code stringlengths 3 1.18M | language stringclasses 1 value |
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/*
* Copyright (C) 2007 The Guava Authors
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package com.google.common.collect;
import com.google.common.annotations.GwtCompatible;
import java.util.LinkedHashMap;
/**
* A {@code Multiset} implementation with predictable iteration order. Its
* iterator orders elements according to when the first occurrence of the
* element was added. When the multiset contains multiple instances of an
* element, those instances are consecutive in the iteration order. If all
* occurrences of an element are removed, after which that element is added to
* the multiset, the element will appear at the end of the iteration.
*
* <p>See the Guava User Guide article on <a href=
* "http://code.google.com/p/guava-libraries/wiki/NewCollectionTypesExplained#Multiset">
* {@code Multiset}</a>.
*
* @author Kevin Bourrillion
* @author Jared Levy
* @since 2.0 (imported from Google Collections Library)
*/
@GwtCompatible(serializable = true, emulated = true)
@SuppressWarnings("serial") // we're overriding default serialization
public final class LinkedHashMultiset<E> extends AbstractMapBasedMultiset<E> {
/**
* Creates a new, empty {@code LinkedHashMultiset} using the default initial
* capacity.
*/
public static <E> LinkedHashMultiset<E> create() {
return new LinkedHashMultiset<E>();
}
/**
* Creates a new, empty {@code LinkedHashMultiset} with the specified expected
* number of distinct elements.
*
* @param distinctElements the expected number of distinct elements
* @throws IllegalArgumentException if {@code distinctElements} is negative
*/
public static <E> LinkedHashMultiset<E> create(int distinctElements) {
return new LinkedHashMultiset<E>(distinctElements);
}
/**
* Creates a new {@code LinkedHashMultiset} containing the specified elements.
*
* <p>This implementation is highly efficient when {@code elements} is itself
* a {@link Multiset}.
*
* @param elements the elements that the multiset should contain
*/
public static <E> LinkedHashMultiset<E> create(
Iterable<? extends E> elements) {
LinkedHashMultiset<E> multiset =
create(Multisets.inferDistinctElements(elements));
Iterables.addAll(multiset, elements);
return multiset;
}
private LinkedHashMultiset() {
super(new LinkedHashMap<E, Count>());
}
private LinkedHashMultiset(int distinctElements) {
// Could use newLinkedHashMapWithExpectedSize() if it existed
super(new LinkedHashMap<E, Count>(Maps.capacity(distinctElements)));
}
}
| Java |
/*
* Copyright (C) 2010 The Guava Authors
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package com.google.common.collect;
import java.util.List;
/**
* GWT emulation of {@link ImmutableAsList}.
*
* @author Hayward Chan
*/
final class ImmutableAsList<E> extends RegularImmutableList<E> {
ImmutableAsList(List<E> delegate) {
super(delegate);
}
}
| Java |
/*
* Copyright (C) 2009 The Guava Authors
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package com.google.common.collect;
import static com.google.common.base.Preconditions.checkNotNull;
import com.google.common.annotations.Beta;
import com.google.common.annotations.GwtCompatible;
import java.util.Arrays;
import java.util.Collection;
import java.util.Comparator;
import java.util.LinkedHashMap;
import java.util.Map.Entry;
import java.util.TreeMap;
import javax.annotation.Nullable;
/**
* An immutable {@link SetMultimap} with reliable user-specified key and value
* iteration order. Does not permit null keys or values.
*
* <p>Unlike {@link Multimaps#unmodifiableSetMultimap(SetMultimap)}, which is
* a <i>view</i> of a separate multimap which can still change, an instance of
* {@code ImmutableSetMultimap} contains its own data and will <i>never</i>
* change. {@code ImmutableSetMultimap} is convenient for
* {@code public static final} multimaps ("constant multimaps") and also lets
* you easily make a "defensive copy" of a multimap provided to your class by
* a caller.
*
* <p><b>Note:</b> Although this class is not final, it cannot be subclassed as
* it has no public or protected constructors. Thus, instances of this class
* are guaranteed to be immutable.
*
* <p>See the Guava User Guide article on <a href=
* "http://code.google.com/p/guava-libraries/wiki/ImmutableCollectionsExplained">
* immutable collections</a>.
*
* @author Mike Ward
* @since 2.0 (imported from Google Collections Library)
*/
@GwtCompatible(serializable = true, emulated = true)
public class ImmutableSetMultimap<K, V>
extends ImmutableMultimap<K, V>
implements SetMultimap<K, V> {
/** Returns the empty multimap. */
// Casting is safe because the multimap will never hold any elements.
@SuppressWarnings("unchecked")
public static <K, V> ImmutableSetMultimap<K, V> of() {
return (ImmutableSetMultimap<K, V>) EmptyImmutableSetMultimap.INSTANCE;
}
/**
* Returns an immutable multimap containing a single entry.
*/
public static <K, V> ImmutableSetMultimap<K, V> of(K k1, V v1) {
ImmutableSetMultimap.Builder<K, V> builder = ImmutableSetMultimap.builder();
builder.put(k1, v1);
return builder.build();
}
/**
* Returns an immutable multimap containing the given entries, in order.
* Repeated occurrences of an entry (according to {@link Object#equals}) after
* the first are ignored.
*/
public static <K, V> ImmutableSetMultimap<K, V> of(K k1, V v1, K k2, V v2) {
ImmutableSetMultimap.Builder<K, V> builder = ImmutableSetMultimap.builder();
builder.put(k1, v1);
builder.put(k2, v2);
return builder.build();
}
/**
* Returns an immutable multimap containing the given entries, in order.
* Repeated occurrences of an entry (according to {@link Object#equals}) after
* the first are ignored.
*/
public static <K, V> ImmutableSetMultimap<K, V> of(
K k1, V v1, K k2, V v2, K k3, V v3) {
ImmutableSetMultimap.Builder<K, V> builder = ImmutableSetMultimap.builder();
builder.put(k1, v1);
builder.put(k2, v2);
builder.put(k3, v3);
return builder.build();
}
/**
* Returns an immutable multimap containing the given entries, in order.
* Repeated occurrences of an entry (according to {@link Object#equals}) after
* the first are ignored.
*/
public static <K, V> ImmutableSetMultimap<K, V> of(
K k1, V v1, K k2, V v2, K k3, V v3, K k4, V v4) {
ImmutableSetMultimap.Builder<K, V> builder = ImmutableSetMultimap.builder();
builder.put(k1, v1);
builder.put(k2, v2);
builder.put(k3, v3);
builder.put(k4, v4);
return builder.build();
}
/**
* Returns an immutable multimap containing the given entries, in order.
* Repeated occurrences of an entry (according to {@link Object#equals}) after
* the first are ignored.
*/
public static <K, V> ImmutableSetMultimap<K, V> of(
K k1, V v1, K k2, V v2, K k3, V v3, K k4, V v4, K k5, V v5) {
ImmutableSetMultimap.Builder<K, V> builder = ImmutableSetMultimap.builder();
builder.put(k1, v1);
builder.put(k2, v2);
builder.put(k3, v3);
builder.put(k4, v4);
builder.put(k5, v5);
return builder.build();
}
// looking for of() with > 5 entries? Use the builder instead.
/**
* Returns a new {@link Builder}.
*/
public static <K, V> Builder<K, V> builder() {
return new Builder<K, V>();
}
/**
* Multimap for {@link ImmutableSetMultimap.Builder} that maintains key
* and value orderings and performs better than {@link LinkedHashMultimap}.
*/
private static class BuilderMultimap<K, V> extends AbstractMultimap<K, V> {
BuilderMultimap() {
super(new LinkedHashMap<K, Collection<V>>());
}
@Override Collection<V> createCollection() {
return Sets.newLinkedHashSet();
}
private static final long serialVersionUID = 0;
}
/**
* Multimap for {@link ImmutableSetMultimap.Builder} that sorts keys and
* maintains value orderings.
*/
private static class SortedKeyBuilderMultimap<K, V>
extends AbstractMultimap<K, V> {
SortedKeyBuilderMultimap(
Comparator<? super K> keyComparator, Multimap<K, V> multimap) {
super(new TreeMap<K, Collection<V>>(keyComparator));
putAll(multimap);
}
@Override Collection<V> createCollection() {
return Sets.newLinkedHashSet();
}
private static final long serialVersionUID = 0;
}
/**
* A builder for creating immutable {@code SetMultimap} instances, especially
* {@code public static final} multimaps ("constant multimaps"). Example:
* <pre> {@code
*
* static final Multimap<String, Integer> STRING_TO_INTEGER_MULTIMAP =
* new ImmutableSetMultimap.Builder<String, Integer>()
* .put("one", 1)
* .putAll("several", 1, 2, 3)
* .putAll("many", 1, 2, 3, 4, 5)
* .build();}</pre>
*
* Builder instances can be reused; it is safe to call {@link #build} multiple
* times to build multiple multimaps in series. Each multimap contains the
* key-value mappings in the previously created multimaps.
*
* @since 2.0 (imported from Google Collections Library)
*/
public static final class Builder<K, V>
extends ImmutableMultimap.Builder<K, V> {
/**
* Creates a new builder. The returned builder is equivalent to the builder
* generated by {@link ImmutableSetMultimap#builder}.
*/
public Builder() {
builderMultimap = new BuilderMultimap<K, V>();
}
/**
* Adds a key-value mapping to the built multimap if it is not already
* present.
*/
@Override public Builder<K, V> put(K key, V value) {
builderMultimap.put(checkNotNull(key), checkNotNull(value));
return this;
}
/**
* Adds an entry to the built multimap if it is not already present.
*
* @since 11.0
*/
@Override public Builder<K, V> put(Entry<? extends K, ? extends V> entry) {
builderMultimap.put(
checkNotNull(entry.getKey()), checkNotNull(entry.getValue()));
return this;
}
@Override public Builder<K, V> putAll(K key, Iterable<? extends V> values) {
Collection<V> collection = builderMultimap.get(checkNotNull(key));
for (V value : values) {
collection.add(checkNotNull(value));
}
return this;
}
@Override public Builder<K, V> putAll(K key, V... values) {
return putAll(key, Arrays.asList(values));
}
@Override public Builder<K, V> putAll(
Multimap<? extends K, ? extends V> multimap) {
for (Entry<? extends K, ? extends Collection<? extends V>> entry
: multimap.asMap().entrySet()) {
putAll(entry.getKey(), entry.getValue());
}
return this;
}
/**
* {@inheritDoc}
*
* @since 8.0
*/
@Beta @Override
public Builder<K, V> orderKeysBy(Comparator<? super K> keyComparator) {
builderMultimap = new SortedKeyBuilderMultimap<K, V>(
checkNotNull(keyComparator), builderMultimap);
return this;
}
/**
* Specifies the ordering of the generated multimap's values for each key.
*
* <p>If this method is called, the sets returned by the {@code get()}
* method of the generated multimap and its {@link Multimap#asMap()} view
* are {@link ImmutableSortedSet} instances. However, serialization does not
* preserve that property, though it does maintain the key and value
* ordering.
*
* @since 8.0
*/
// TODO: Make serialization behavior consistent.
@Beta @Override
public Builder<K, V> orderValuesBy(Comparator<? super V> valueComparator) {
super.orderValuesBy(valueComparator);
return this;
}
/**
* Returns a newly-created immutable set multimap.
*/
@Override public ImmutableSetMultimap<K, V> build() {
return copyOf(builderMultimap, valueComparator);
}
}
/**
* Returns an immutable set multimap containing the same mappings as
* {@code multimap}. The generated multimap's key and value orderings
* correspond to the iteration ordering of the {@code multimap.asMap()} view.
* Repeated occurrences of an entry in the multimap after the first are
* ignored.
*
* <p>Despite the method name, this method attempts to avoid actually copying
* the data when it is safe to do so. The exact circumstances under which a
* copy will or will not be performed are undocumented and subject to change.
*
* @throws NullPointerException if any key or value in {@code multimap} is
* null
*/
public static <K, V> ImmutableSetMultimap<K, V> copyOf(
Multimap<? extends K, ? extends V> multimap) {
return copyOf(multimap, null);
}
private static <K, V> ImmutableSetMultimap<K, V> copyOf(
Multimap<? extends K, ? extends V> multimap,
Comparator<? super V> valueComparator) {
checkNotNull(multimap); // eager for GWT
if (multimap.isEmpty() && valueComparator == null) {
return of();
}
if (multimap instanceof ImmutableSetMultimap) {
@SuppressWarnings("unchecked") // safe since multimap is not writable
ImmutableSetMultimap<K, V> kvMultimap
= (ImmutableSetMultimap<K, V>) multimap;
if (!kvMultimap.isPartialView()) {
return kvMultimap;
}
}
ImmutableMap.Builder<K, ImmutableSet<V>> builder = ImmutableMap.builder();
int size = 0;
for (Entry<? extends K, ? extends Collection<? extends V>> entry
: multimap.asMap().entrySet()) {
K key = entry.getKey();
Collection<? extends V> values = entry.getValue();
ImmutableSet<V> set = (valueComparator == null)
? ImmutableSet.copyOf(values)
: ImmutableSortedSet.copyOf(valueComparator, values);
if (!set.isEmpty()) {
builder.put(key, set);
size += set.size();
}
}
return new ImmutableSetMultimap<K, V>(
builder.build(), size, valueComparator);
}
// Returned by get() when values are sorted and a missing key is provided.
private final transient ImmutableSortedSet<V> emptySet;
ImmutableSetMultimap(ImmutableMap<K, ImmutableSet<V>> map, int size,
@Nullable Comparator<? super V> valueComparator) {
super(map, size);
this.emptySet = (valueComparator == null)
? null : ImmutableSortedSet.<V>emptySet(valueComparator);
}
// views
/**
* Returns an immutable set of the values for the given key. If no mappings
* in the multimap have the provided key, an empty immutable set is returned.
* The values are in the same order as the parameters used to build this
* multimap.
*/
@Override public ImmutableSet<V> get(@Nullable K key) {
// This cast is safe as its type is known in constructor.
ImmutableSet<V> set = (ImmutableSet<V>) map.get(key);
if (set != null) {
return set;
} else if (emptySet != null) {
return emptySet;
} else {
return ImmutableSet.<V>of();
}
}
private transient ImmutableSetMultimap<V, K> inverse;
/**
* {@inheritDoc}
*
* <p>Because an inverse of a set multimap cannot contain multiple pairs with the same key and
* value, this method returns an {@code ImmutableSetMultimap} rather than the
* {@code ImmutableMultimap} specified in the {@code ImmutableMultimap} class.
*
* @since 11
*/
@Beta
public ImmutableSetMultimap<V, K> inverse() {
ImmutableSetMultimap<V, K> result = inverse;
return (result == null) ? (inverse = invert()) : result;
}
private ImmutableSetMultimap<V, K> invert() {
Builder<V, K> builder = builder();
for (Entry<K, V> entry : entries()) {
builder.put(entry.getValue(), entry.getKey());
}
ImmutableSetMultimap<V, K> invertedMultimap = builder.build();
invertedMultimap.inverse = this;
return invertedMultimap;
}
/**
* Guaranteed to throw an exception and leave the multimap unmodified.
*
* @throws UnsupportedOperationException always
*/
@Override public ImmutableSet<V> removeAll(Object key) {
throw new UnsupportedOperationException();
}
/**
* Guaranteed to throw an exception and leave the multimap unmodified.
*
* @throws UnsupportedOperationException always
*/
@Override public ImmutableSet<V> replaceValues(
K key, Iterable<? extends V> values) {
throw new UnsupportedOperationException();
}
private transient ImmutableSet<Entry<K, V>> entries;
/**
* Returns an immutable collection of all key-value pairs in the multimap.
* Its iterator traverses the values for the first key, the values for the
* second key, and so on.
*/
// TODO(kevinb): Fix this so that two copies of the entries are not created.
@Override public ImmutableSet<Entry<K, V>> entries() {
ImmutableSet<Entry<K, V>> result = entries;
return (result == null)
? (entries = ImmutableSet.copyOf(super.entries()))
: result;
}
}
| Java |
/*
* Copyright (C) 2007 The Guava Authors
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package com.google.common.collect;
import static com.google.common.base.Preconditions.checkArgument;
import static com.google.common.base.Preconditions.checkNotNull;
import com.google.common.annotations.Beta;
import com.google.common.annotations.GwtCompatible;
import com.google.common.base.Function;
import com.google.common.base.Objects;
import com.google.common.base.Optional;
import com.google.common.base.Preconditions;
import com.google.common.base.Predicate;
import java.util.Arrays;
import java.util.Collection;
import java.util.Comparator;
import java.util.Iterator;
import java.util.List;
import java.util.NoSuchElementException;
import java.util.Queue;
import java.util.RandomAccess;
import java.util.Set;
import java.util.SortedSet;
import javax.annotation.Nullable;
/**
* This class contains static utility methods that operate on or return objects
* of type {@code Iterable}. Except as noted, each method has a corresponding
* {@link Iterator}-based method in the {@link Iterators} class.
*
* <p><i>Performance notes:</i> Unless otherwise noted, all of the iterables
* produced in this class are <i>lazy</i>, which means that their iterators
* only advance the backing iteration when absolutely necessary.
*
* <p>See the Guava User Guide article on <a href=
* "http://code.google.com/p/guava-libraries/wiki/CollectionUtilitiesExplained#Iterables">
* {@code Iterables}</a>.
*
* @author Kevin Bourrillion
* @author Jared Levy
* @since 2.0 (imported from Google Collections Library)
*/
@GwtCompatible(emulated = true)
public final class Iterables {
private Iterables() {}
/** Returns an unmodifiable view of {@code iterable}. */
public static <T> Iterable<T> unmodifiableIterable(
final Iterable<T> iterable) {
checkNotNull(iterable);
if (iterable instanceof UnmodifiableIterable ||
iterable instanceof ImmutableCollection) {
return iterable;
}
return new UnmodifiableIterable<T>(iterable);
}
/**
* Simply returns its argument.
*
* @deprecated no need to use this
* @since 10.0
*/
@Deprecated public static <E> Iterable<E> unmodifiableIterable(
ImmutableCollection<E> iterable) {
return checkNotNull(iterable);
}
private static final class UnmodifiableIterable<T> implements Iterable<T> {
private final Iterable<T> iterable;
private UnmodifiableIterable(Iterable<T> iterable) {
this.iterable = iterable;
}
@Override
public Iterator<T> iterator() {
return Iterators.unmodifiableIterator(iterable.iterator());
}
@Override
public String toString() {
return iterable.toString();
}
// no equals and hashCode; it would break the contract!
}
/**
* Returns the number of elements in {@code iterable}.
*/
public static int size(Iterable<?> iterable) {
return (iterable instanceof Collection)
? ((Collection<?>) iterable).size()
: Iterators.size(iterable.iterator());
}
/**
* Returns {@code true} if {@code iterable} contains {@code element}; that is,
* any object for which {@code equals(element)} is true.
*/
public static boolean contains(Iterable<?> iterable, @Nullable Object element)
{
if (iterable instanceof Collection) {
Collection<?> collection = (Collection<?>) iterable;
try {
return collection.contains(element);
} catch (NullPointerException e) {
return false;
} catch (ClassCastException e) {
return false;
}
}
return Iterators.contains(iterable.iterator(), element);
}
/**
* Removes, from an iterable, every element that belongs to the provided
* collection.
*
* <p>This method calls {@link Collection#removeAll} if {@code iterable} is a
* collection, and {@link Iterators#removeAll} otherwise.
*
* @param removeFrom the iterable to (potentially) remove elements from
* @param elementsToRemove the elements to remove
* @return {@code true} if any element was removed from {@code iterable}
*/
public static boolean removeAll(
Iterable<?> removeFrom, Collection<?> elementsToRemove) {
return (removeFrom instanceof Collection)
? ((Collection<?>) removeFrom).removeAll(checkNotNull(elementsToRemove))
: Iterators.removeAll(removeFrom.iterator(), elementsToRemove);
}
/**
* Removes, from an iterable, every element that does not belong to the
* provided collection.
*
* <p>This method calls {@link Collection#retainAll} if {@code iterable} is a
* collection, and {@link Iterators#retainAll} otherwise.
*
* @param removeFrom the iterable to (potentially) remove elements from
* @param elementsToRetain the elements to retain
* @return {@code true} if any element was removed from {@code iterable}
*/
public static boolean retainAll(
Iterable<?> removeFrom, Collection<?> elementsToRetain) {
return (removeFrom instanceof Collection)
? ((Collection<?>) removeFrom).retainAll(checkNotNull(elementsToRetain))
: Iterators.retainAll(removeFrom.iterator(), elementsToRetain);
}
/**
* Removes, from an iterable, every element that satisfies the provided
* predicate.
*
* @param removeFrom the iterable to (potentially) remove elements from
* @param predicate a predicate that determines whether an element should
* be removed
* @return {@code true} if any elements were removed from the iterable
*
* @throws UnsupportedOperationException if the iterable does not support
* {@code remove()}.
* @since 2.0
*/
public static <T> boolean removeIf(
Iterable<T> removeFrom, Predicate<? super T> predicate) {
if (removeFrom instanceof RandomAccess && removeFrom instanceof List) {
return removeIfFromRandomAccessList(
(List<T>) removeFrom, checkNotNull(predicate));
}
return Iterators.removeIf(removeFrom.iterator(), predicate);
}
private static <T> boolean removeIfFromRandomAccessList(
List<T> list, Predicate<? super T> predicate) {
// Note: Not all random access lists support set() so we need to deal with
// those that don't and attempt the slower remove() based solution.
int from = 0;
int to = 0;
for (; from < list.size(); from++) {
T element = list.get(from);
if (!predicate.apply(element)) {
if (from > to) {
try {
list.set(to, element);
} catch (UnsupportedOperationException e) {
slowRemoveIfForRemainingElements(list, predicate, to, from);
return true;
}
}
to++;
}
}
// Clear the tail of any remaining items
list.subList(to, list.size()).clear();
return from != to;
}
private static <T> void slowRemoveIfForRemainingElements(List<T> list,
Predicate<? super T> predicate, int to, int from) {
// Here we know that:
// * (to < from) and that both are valid indices.
// * Everything with (index < to) should be kept.
// * Everything with (to <= index < from) should be removed.
// * The element with (index == from) should be kept.
// * Everything with (index > from) has not been checked yet.
// Check from the end of the list backwards (minimize expected cost of
// moving elements when remove() is called). Stop before 'from' because
// we already know that should be kept.
for (int n = list.size() - 1; n > from; n--) {
if (predicate.apply(list.get(n))) {
list.remove(n);
}
}
// And now remove everything in the range [to, from) (going backwards).
for (int n = from - 1; n >= to; n--) {
list.remove(n);
}
}
/**
* Determines whether two iterables contain equal elements in the same order.
* More specifically, this method returns {@code true} if {@code iterable1}
* and {@code iterable2} contain the same number of elements and every element
* of {@code iterable1} is equal to the corresponding element of
* {@code iterable2}.
*/
public static boolean elementsEqual(
Iterable<?> iterable1, Iterable<?> iterable2) {
return Iterators.elementsEqual(iterable1.iterator(), iterable2.iterator());
}
/**
* Returns a string representation of {@code iterable}, with the format
* {@code [e1, e2, ..., en]}.
*/
public static String toString(Iterable<?> iterable) {
return Iterators.toString(iterable.iterator());
}
/**
* Returns the single element contained in {@code iterable}.
*
* @throws NoSuchElementException if the iterable is empty
* @throws IllegalArgumentException if the iterable contains multiple
* elements
*/
public static <T> T getOnlyElement(Iterable<T> iterable) {
return Iterators.getOnlyElement(iterable.iterator());
}
/**
* Returns the single element contained in {@code iterable}, or {@code
* defaultValue} if the iterable is empty.
*
* @throws IllegalArgumentException if the iterator contains multiple
* elements
*/
public static <T> T getOnlyElement(
Iterable<T> iterable, @Nullable T defaultValue) {
return Iterators.getOnlyElement(iterable.iterator(), defaultValue);
}
/**
* Copies an iterable's elements into an array.
*
* @param iterable the iterable to copy
* @return a newly-allocated array into which all the elements of the iterable
* have been copied
*/
static Object[] toArray(Iterable<?> iterable) {
return toCollection(iterable).toArray();
}
/**
* Converts an iterable into a collection. If the iterable is already a
* collection, it is returned. Otherwise, an {@link java.util.ArrayList} is
* created with the contents of the iterable in the same iteration order.
*/
private static <E> Collection<E> toCollection(Iterable<E> iterable) {
return (iterable instanceof Collection)
? (Collection<E>) iterable
: Lists.newArrayList(iterable.iterator());
}
/**
* Adds all elements in {@code iterable} to {@code collection}.
*
* @return {@code true} if {@code collection} was modified as a result of this
* operation.
*/
public static <T> boolean addAll(
Collection<T> addTo, Iterable<? extends T> elementsToAdd) {
if (elementsToAdd instanceof Collection) {
Collection<? extends T> c = Collections2.cast(elementsToAdd);
return addTo.addAll(c);
}
return Iterators.addAll(addTo, elementsToAdd.iterator());
}
/**
* Returns the number of elements in the specified iterable that equal the
* specified object. This implementation avoids a full iteration when the
* iterable is a {@link Multiset} or {@link Set}.
*
* @see Collections#frequency
*/
public static int frequency(Iterable<?> iterable, @Nullable Object element) {
if ((iterable instanceof Multiset)) {
return ((Multiset<?>) iterable).count(element);
}
if ((iterable instanceof Set)) {
return ((Set<?>) iterable).contains(element) ? 1 : 0;
}
return Iterators.frequency(iterable.iterator(), element);
}
/**
* Returns an iterable whose iterators cycle indefinitely over the elements of
* {@code iterable}.
*
* <p>That iterator supports {@code remove()} if {@code iterable.iterator()}
* does. After {@code remove()} is called, subsequent cycles omit the removed
* element, which is no longer in {@code iterable}. The iterator's
* {@code hasNext()} method returns {@code true} until {@code iterable} is
* empty.
*
* <p><b>Warning:</b> Typical uses of the resulting iterator may produce an
* infinite loop. You should use an explicit {@code break} or be certain that
* you will eventually remove all the elements.
*
* <p>To cycle over the iterable {@code n} times, use the following:
* {@code Iterables.concat(Collections.nCopies(n, iterable))}
*/
public static <T> Iterable<T> cycle(final Iterable<T> iterable) {
checkNotNull(iterable);
return new Iterable<T>() {
@Override
public Iterator<T> iterator() {
return Iterators.cycle(iterable);
}
@Override public String toString() {
return iterable.toString() + " (cycled)";
}
};
}
/**
* Returns an iterable whose iterators cycle indefinitely over the provided
* elements.
*
* <p>After {@code remove} is invoked on a generated iterator, the removed
* element will no longer appear in either that iterator or any other iterator
* created from the same source iterable. That is, this method behaves exactly
* as {@code Iterables.cycle(Lists.newArrayList(elements))}. The iterator's
* {@code hasNext} method returns {@code true} until all of the original
* elements have been removed.
*
* <p><b>Warning:</b> Typical uses of the resulting iterator may produce an
* infinite loop. You should use an explicit {@code break} or be certain that
* you will eventually remove all the elements.
*
* <p>To cycle over the elements {@code n} times, use the following:
* {@code Iterables.concat(Collections.nCopies(n, Arrays.asList(elements)))}
*/
public static <T> Iterable<T> cycle(T... elements) {
return cycle(Lists.newArrayList(elements));
}
/**
* Combines two iterables into a single iterable. The returned iterable has an
* iterator that traverses the elements in {@code a}, followed by the elements
* in {@code b}. The source iterators are not polled until necessary.
*
* <p>The returned iterable's iterator supports {@code remove()} when the
* corresponding input iterator supports it.
*/
@SuppressWarnings("unchecked")
public static <T> Iterable<T> concat(
Iterable<? extends T> a, Iterable<? extends T> b) {
checkNotNull(a);
checkNotNull(b);
return concat(Arrays.asList(a, b));
}
/**
* Combines three iterables into a single iterable. The returned iterable has
* an iterator that traverses the elements in {@code a}, followed by the
* elements in {@code b}, followed by the elements in {@code c}. The source
* iterators are not polled until necessary.
*
* <p>The returned iterable's iterator supports {@code remove()} when the
* corresponding input iterator supports it.
*/
@SuppressWarnings("unchecked")
public static <T> Iterable<T> concat(Iterable<? extends T> a,
Iterable<? extends T> b, Iterable<? extends T> c) {
checkNotNull(a);
checkNotNull(b);
checkNotNull(c);
return concat(Arrays.asList(a, b, c));
}
/**
* Combines four iterables into a single iterable. The returned iterable has
* an iterator that traverses the elements in {@code a}, followed by the
* elements in {@code b}, followed by the elements in {@code c}, followed by
* the elements in {@code d}. The source iterators are not polled until
* necessary.
*
* <p>The returned iterable's iterator supports {@code remove()} when the
* corresponding input iterator supports it.
*/
@SuppressWarnings("unchecked")
public static <T> Iterable<T> concat(Iterable<? extends T> a,
Iterable<? extends T> b, Iterable<? extends T> c,
Iterable<? extends T> d) {
checkNotNull(a);
checkNotNull(b);
checkNotNull(c);
checkNotNull(d);
return concat(Arrays.asList(a, b, c, d));
}
/**
* Combines multiple iterables into a single iterable. The returned iterable
* has an iterator that traverses the elements of each iterable in
* {@code inputs}. The input iterators are not polled until necessary.
*
* <p>The returned iterable's iterator supports {@code remove()} when the
* corresponding input iterator supports it.
*
* @throws NullPointerException if any of the provided iterables is null
*/
public static <T> Iterable<T> concat(Iterable<? extends T>... inputs) {
return concat(ImmutableList.copyOf(inputs));
}
/**
* Combines multiple iterables into a single iterable. The returned iterable
* has an iterator that traverses the elements of each iterable in
* {@code inputs}. The input iterators are not polled until necessary.
*
* <p>The returned iterable's iterator supports {@code remove()} when the
* corresponding input iterator supports it. The methods of the returned
* iterable may throw {@code NullPointerException} if any of the input
* iterators is null.
*/
public static <T> Iterable<T> concat(
final Iterable<? extends Iterable<? extends T>> inputs) {
checkNotNull(inputs);
return new IterableWithToString<T>() {
@Override
public Iterator<T> iterator() {
return Iterators.concat(iterators(inputs));
}
};
}
/**
* Returns an iterator over the iterators of the given iterables.
*/
private static <T> UnmodifiableIterator<Iterator<? extends T>> iterators(
Iterable<? extends Iterable<? extends T>> iterables) {
final Iterator<? extends Iterable<? extends T>> iterableIterator =
iterables.iterator();
return new UnmodifiableIterator<Iterator<? extends T>>() {
@Override
public boolean hasNext() {
return iterableIterator.hasNext();
}
@Override
public Iterator<? extends T> next() {
return iterableIterator.next().iterator();
}
};
}
/**
* Divides an iterable into unmodifiable sublists of the given size (the final
* iterable may be smaller). For example, partitioning an iterable containing
* {@code [a, b, c, d, e]} with a partition size of 3 yields {@code
* [[a, b, c], [d, e]]} -- an outer iterable containing two inner lists of
* three and two elements, all in the original order.
*
* <p>Iterators returned by the returned iterable do not support the {@link
* Iterator#remove()} method. The returned lists implement {@link
* RandomAccess}, whether or not the input list does.
*
* <p><b>Note:</b> if {@code iterable} is a {@link List}, use {@link
* Lists#partition(List, int)} instead.
*
* @param iterable the iterable to return a partitioned view of
* @param size the desired size of each partition (the last may be smaller)
* @return an iterable of unmodifiable lists containing the elements of {@code
* iterable} divided into partitions
* @throws IllegalArgumentException if {@code size} is nonpositive
*/
public static <T> Iterable<List<T>> partition(
final Iterable<T> iterable, final int size) {
checkNotNull(iterable);
checkArgument(size > 0);
return new IterableWithToString<List<T>>() {
@Override
public Iterator<List<T>> iterator() {
return Iterators.partition(iterable.iterator(), size);
}
};
}
/**
* Divides an iterable into unmodifiable sublists of the given size, padding
* the final iterable with null values if necessary. For example, partitioning
* an iterable containing {@code [a, b, c, d, e]} with a partition size of 3
* yields {@code [[a, b, c], [d, e, null]]} -- an outer iterable containing
* two inner lists of three elements each, all in the original order.
*
* <p>Iterators returned by the returned iterable do not support the {@link
* Iterator#remove()} method.
*
* @param iterable the iterable to return a partitioned view of
* @param size the desired size of each partition
* @return an iterable of unmodifiable lists containing the elements of {@code
* iterable} divided into partitions (the final iterable may have
* trailing null elements)
* @throws IllegalArgumentException if {@code size} is nonpositive
*/
public static <T> Iterable<List<T>> paddedPartition(
final Iterable<T> iterable, final int size) {
checkNotNull(iterable);
checkArgument(size > 0);
return new IterableWithToString<List<T>>() {
@Override
public Iterator<List<T>> iterator() {
return Iterators.paddedPartition(iterable.iterator(), size);
}
};
}
/**
* Returns the elements of {@code unfiltered} that satisfy a predicate. The
* resulting iterable's iterator does not support {@code remove()}.
*/
public static <T> Iterable<T> filter(
final Iterable<T> unfiltered, final Predicate<? super T> predicate) {
checkNotNull(unfiltered);
checkNotNull(predicate);
return new IterableWithToString<T>() {
@Override
public Iterator<T> iterator() {
return Iterators.filter(unfiltered.iterator(), predicate);
}
};
}
/**
* Returns {@code true} if one or more elements in {@code iterable} satisfy
* the predicate.
*/
public static <T> boolean any(
Iterable<T> iterable, Predicate<? super T> predicate) {
return Iterators.any(iterable.iterator(), predicate);
}
/**
* Returns {@code true} if every element in {@code iterable} satisfies the
* predicate. If {@code iterable} is empty, {@code true} is returned.
*/
public static <T> boolean all(
Iterable<T> iterable, Predicate<? super T> predicate) {
return Iterators.all(iterable.iterator(), predicate);
}
/**
* Returns the first element in {@code iterable} that satisfies the given
* predicate; use this method only when such an element is known to exist. If
* it is possible that <i>no</i> element will match, use {@link
* #tryFind)} or {@link #find(Iterable, Predicate, T)} instead.
*
* @throws NoSuchElementException if no element in {@code iterable} matches
* the given predicate
*/
public static <T> T find(Iterable<T> iterable,
Predicate<? super T> predicate) {
return Iterators.find(iterable.iterator(), predicate);
}
/**
* Returns the first element in {@code iterable} that satisfies the given
* predicate, or {@code defaultValue} if none found. Note that this can
* usually be handled more naturally using {@code
* tryFind(iterable, predicate).or(defaultValue)}.
*
* @since 7.0
*/
public static <T> T find(Iterable<T> iterable,
Predicate<? super T> predicate, @Nullable T defaultValue) {
return Iterators.find(iterable.iterator(), predicate, defaultValue);
}
/**
* Returns an {@link Optional} containing the first element in {@code
* iterable} that satisfies the given predicate, if such an element exists.
*
* <p><b>Warning:</b> avoid using a {@code predicate} that matches {@code
* null}. If {@code null} is matched in {@code iterable}, a
* NullPointerException will be thrown.
*
* @since 11.0
*/
public static <T> Optional<T> tryFind(Iterable<T> iterable,
Predicate<? super T> predicate) {
return Iterators.tryFind(iterable.iterator(), predicate);
}
/**
* Returns the index in {@code iterable} of the first element that satisfies
* the provided {@code predicate}, or {@code -1} if the Iterable has no such
* elements.
*
* <p>More formally, returns the lowest index {@code i} such that
* {@code predicate.apply(Iterables.get(iterable, i))} returns {@code true},
* or {@code -1} if there is no such index.
*
* @since 2.0
*/
public static <T> int indexOf(
Iterable<T> iterable, Predicate<? super T> predicate) {
return Iterators.indexOf(iterable.iterator(), predicate);
}
/**
* Returns an iterable that applies {@code function} to each element of {@code
* fromIterable}.
*
* <p>The returned iterable's iterator supports {@code remove()} if the
* provided iterator does. After a successful {@code remove()} call,
* {@code fromIterable} no longer contains the corresponding element.
*
* <p>If the input {@code Iterable} is known to be a {@code List} or other
* {@code Collection}, consider {@link Lists#transform} and {@link
* Collections2#transform}.
*/
public static <F, T> Iterable<T> transform(final Iterable<F> fromIterable,
final Function<? super F, ? extends T> function) {
checkNotNull(fromIterable);
checkNotNull(function);
return new IterableWithToString<T>() {
@Override
public Iterator<T> iterator() {
return Iterators.transform(fromIterable.iterator(), function);
}
};
}
/**
* Returns the element at the specified position in an iterable.
*
* @param position position of the element to return
* @return the element at the specified position in {@code iterable}
* @throws IndexOutOfBoundsException if {@code position} is negative or
* greater than or equal to the size of {@code iterable}
*/
public static <T> T get(Iterable<T> iterable, int position) {
checkNotNull(iterable);
if (iterable instanceof List) {
return ((List<T>) iterable).get(position);
}
if (iterable instanceof Collection) {
// Can check both ends
Collection<T> collection = (Collection<T>) iterable;
Preconditions.checkElementIndex(position, collection.size());
} else {
// Can only check the lower end
checkNonnegativeIndex(position);
}
return Iterators.get(iterable.iterator(), position);
}
private static void checkNonnegativeIndex(int position) {
if (position < 0) {
throw new IndexOutOfBoundsException(
"position cannot be negative: " + position);
}
}
/**
* Returns the element at the specified position in an iterable or a default
* value otherwise.
*
* @param position position of the element to return
* @param defaultValue the default value to return if {@code position} is
* greater than or equal to the size of the iterable
* @return the element at the specified position in {@code iterable} or
* {@code defaultValue} if {@code iterable} contains fewer than
* {@code position + 1} elements.
* @throws IndexOutOfBoundsException if {@code position} is negative
* @since 4.0
*/
public static <T> T get(Iterable<T> iterable, int position,
@Nullable T defaultValue) {
checkNotNull(iterable);
checkNonnegativeIndex(position);
try {
return get(iterable, position);
} catch (IndexOutOfBoundsException e) {
return defaultValue;
}
}
/**
* Returns the first element in {@code iterable} or {@code defaultValue} if
* the iterable is empty. The {@link Iterators} analog to this method is
* {@link Iterators#getNext}.
*
* @param defaultValue the default value to return if the iterable is empty
* @return the first element of {@code iterable} or the default value
* @since 7.0
*/
public static <T> T getFirst(Iterable<T> iterable, @Nullable T defaultValue) {
return Iterators.getNext(iterable.iterator(), defaultValue);
}
/**
* Returns the last element of {@code iterable}.
*
* @return the last element of {@code iterable}
* @throws NoSuchElementException if the iterable is empty
*/
public static <T> T getLast(Iterable<T> iterable) {
// TODO(kevinb): Support a concurrently modified collection?
if (iterable instanceof List) {
List<T> list = (List<T>) iterable;
if (list.isEmpty()) {
throw new NoSuchElementException();
}
return getLastInNonemptyList(list);
}
/*
* TODO(kevinb): consider whether this "optimization" is worthwhile. Users
* with SortedSets tend to know they are SortedSets and probably would not
* call this method.
*/
if (iterable instanceof SortedSet) {
SortedSet<T> sortedSet = (SortedSet<T>) iterable;
return sortedSet.last();
}
return Iterators.getLast(iterable.iterator());
}
/**
* Returns the last element of {@code iterable} or {@code defaultValue} if
* the iterable is empty.
*
* @param defaultValue the value to return if {@code iterable} is empty
* @return the last element of {@code iterable} or the default value
* @since 3.0
*/
public static <T> T getLast(Iterable<T> iterable, @Nullable T defaultValue) {
if (iterable instanceof Collection) {
Collection<T> collection = (Collection<T>) iterable;
if (collection.isEmpty()) {
return defaultValue;
}
}
if (iterable instanceof List) {
List<T> list = (List<T>) iterable;
return getLastInNonemptyList(list);
}
/*
* TODO(kevinb): consider whether this "optimization" is worthwhile. Users
* with SortedSets tend to know they are SortedSets and probably would not
* call this method.
*/
if (iterable instanceof SortedSet) {
SortedSet<T> sortedSet = (SortedSet<T>) iterable;
return sortedSet.last();
}
return Iterators.getLast(iterable.iterator(), defaultValue);
}
private static <T> T getLastInNonemptyList(List<T> list) {
return list.get(list.size() - 1);
}
/**
* Returns a view of {@code iterable} that skips its first
* {@code numberToSkip} elements. If {@code iterable} contains fewer than
* {@code numberToSkip} elements, the returned iterable skips all of its
* elements.
*
* <p>Modifications to the underlying {@link Iterable} before a call to
* {@code iterator()} are reflected in the returned iterator. That is, the
* iterator skips the first {@code numberToSkip} elements that exist when the
* {@code Iterator} is created, not when {@code skip()} is called.
*
* <p>The returned iterable's iterator supports {@code remove()} if the
* iterator of the underlying iterable supports it. Note that it is
* <i>not</i> possible to delete the last skipped element by immediately
* calling {@code remove()} on that iterator, as the {@code Iterator}
* contract states that a call to {@code remove()} before a call to
* {@code next()} will throw an {@link IllegalStateException}.
*
* @since 3.0
*/
public static <T> Iterable<T> skip(final Iterable<T> iterable,
final int numberToSkip) {
checkNotNull(iterable);
checkArgument(numberToSkip >= 0, "number to skip cannot be negative");
if (iterable instanceof List) {
final List<T> list = (List<T>) iterable;
return new IterableWithToString<T>() {
@Override
public Iterator<T> iterator() {
// TODO(kevinb): Support a concurrently modified collection?
return (numberToSkip >= list.size())
? Iterators.<T>emptyIterator()
: list.subList(numberToSkip, list.size()).iterator();
}
};
}
return new IterableWithToString<T>() {
@Override
public Iterator<T> iterator() {
final Iterator<T> iterator = iterable.iterator();
Iterators.skip(iterator, numberToSkip);
/*
* We can't just return the iterator because an immediate call to its
* remove() method would remove one of the skipped elements instead of
* throwing an IllegalStateException.
*/
return new Iterator<T>() {
boolean atStart = true;
@Override
public boolean hasNext() {
return iterator.hasNext();
}
@Override
public T next() {
if (!hasNext()) {
throw new NoSuchElementException();
}
try {
return iterator.next();
} finally {
atStart = false;
}
}
@Override
public void remove() {
if (atStart) {
throw new IllegalStateException();
}
iterator.remove();
}
};
}
};
}
/**
* Creates an iterable with the first {@code limitSize} elements of the given
* iterable. If the original iterable does not contain that many elements, the
* returned iterator will have the same behavior as the original iterable. The
* returned iterable's iterator supports {@code remove()} if the original
* iterator does.
*
* @param iterable the iterable to limit
* @param limitSize the maximum number of elements in the returned iterator
* @throws IllegalArgumentException if {@code limitSize} is negative
* @since 3.0
*/
public static <T> Iterable<T> limit(
final Iterable<T> iterable, final int limitSize) {
checkNotNull(iterable);
checkArgument(limitSize >= 0, "limit is negative");
return new IterableWithToString<T>() {
@Override
public Iterator<T> iterator() {
return Iterators.limit(iterable.iterator(), limitSize);
}
};
}
/**
* Returns a view of the supplied iterable that wraps each generated
* {@link Iterator} through {@link Iterators#consumingIterator(Iterator)}.
*
* <p>Note: If {@code iterable} is a {@link Queue}, the returned iterable will
* get entries from {@link Queue#remove()} since {@link Queue}'s iteration
* order is undefined. Calling {@link Iterator#hasNext()} on a generated
* iterator from the returned iterable may cause an item to be immediately
* dequeued for return on a subsequent call to {@link Iterator#next()}.
*
* @param iterable the iterable to wrap
* @return a view of the supplied iterable that wraps each generated iterator
* through {@link Iterators#consumingIterator(Iterator)}; for queues,
* an iterable that generates iterators that return and consume the
* queue's elements in queue order
*
* @see Iterators#consumingIterator(Iterator)
* @since 2.0
*/
public static <T> Iterable<T> consumingIterable(final Iterable<T> iterable) {
if (iterable instanceof Queue) {
return new Iterable<T>() {
@Override
public Iterator<T> iterator() {
return new ConsumingQueueIterator<T>((Queue<T>) iterable);
}
};
}
checkNotNull(iterable);
return new Iterable<T>() {
@Override
public Iterator<T> iterator() {
return Iterators.consumingIterator(iterable.iterator());
}
};
}
private static class ConsumingQueueIterator<T> extends AbstractIterator<T> {
private final Queue<T> queue;
private ConsumingQueueIterator(Queue<T> queue) {
this.queue = queue;
}
@Override public T computeNext() {
try {
return queue.remove();
} catch (NoSuchElementException e) {
return endOfData();
}
}
}
// Methods only in Iterables, not in Iterators
/**
* Adapts a list to an iterable with reversed iteration order. It is
* especially useful in foreach-style loops: <pre> {@code
*
* List<String> mylist = ...
* for (String str : Iterables.reverse(mylist)) {
* ...
* }}</pre>
*
* There is no corresponding method in {@link Iterators}, since {@link
* Iterable#iterator} can simply be invoked on the result of calling this
* method.
*
* @return an iterable with the same elements as the list, in reverse
*
* @deprecated use {@link Lists#reverse(List)} or {@link
* ImmutableList#reverse()}. <b>This method is scheduled for deletion in
* July 2012.</b>
*/
@Deprecated
public static <T> Iterable<T> reverse(final List<T> list) {
return Lists.reverse(list);
}
/**
* Determines if the given iterable contains no elements.
*
* <p>There is no precise {@link Iterator} equivalent to this method, since
* one can only ask an iterator whether it has any elements <i>remaining</i>
* (which one does using {@link Iterator#hasNext}).
*
* @return {@code true} if the iterable contains no elements
*/
public static boolean isEmpty(Iterable<?> iterable) {
if (iterable instanceof Collection) {
return ((Collection<?>) iterable).isEmpty();
}
return !iterable.iterator().hasNext();
}
// Non-public
/**
* Removes the specified element from the specified iterable.
*
* <p>This method iterates over the iterable, checking each element returned
* by the iterator in turn to see if it equals the object {@code o}. If they
* are equal, it is removed from the iterable with the iterator's
* {@code remove} method. At most one element is removed, even if the iterable
* contains multiple members that equal {@code o}.
*
* <p><b>Warning:</b> Do not use this method for a collection, such as a
* {@link HashSet}, that has a fast {@code remove} method.
*
* @param iterable the iterable from which to remove
* @param o an element to remove from the collection
* @return {@code true} if the iterable changed as a result
* @throws UnsupportedOperationException if the iterator does not support the
* {@code remove} method and the iterable contains the object
*/
static boolean remove(Iterable<?> iterable, @Nullable Object o) {
Iterator<?> i = iterable.iterator();
while (i.hasNext()) {
if (Objects.equal(i.next(), o)) {
i.remove();
return true;
}
}
return false;
}
abstract static class IterableWithToString<E> implements Iterable<E> {
@Override public String toString() {
return Iterables.toString(this);
}
}
/**
* Returns an iterable over the merged contents of all given
* {@code iterables}. Equivalent entries will not be de-duplicated.
*
* <p>Callers must ensure that the source {@code iterables} are in
* non-descending order as this method does not sort its input.
*
* <p>For any equivalent elements across all {@code iterables}, it is
* undefined which element is returned first.
*
* @since 11.0
*/
@Beta
public static <T> Iterable<T> mergeSorted(
final Iterable<? extends Iterable<? extends T>> iterables,
final Comparator<? super T> comparator) {
checkNotNull(iterables, "iterables");
checkNotNull(comparator, "comparator");
Iterable<T> iterable = new Iterable<T>() {
@Override
public Iterator<T> iterator() {
return Iterators.mergeSorted(
Iterables.transform(iterables, Iterables.<T>toIterator()),
comparator);
}
};
return new UnmodifiableIterable<T>(iterable);
}
// TODO(user): Is this the best place for this? Move to fluent functions?
// Useful as a public method?
private static <T> Function<Iterable<? extends T>, Iterator<? extends T>>
toIterator() {
return new Function<Iterable<? extends T>, Iterator<? extends T>>() {
@Override
public Iterator<? extends T> apply(Iterable<? extends T> iterable) {
return iterable.iterator();
}
};
}
}
| Java |
/*
* Copyright (C) 2010 The Guava Authors
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package com.google.common.collect;
import com.google.gwt.user.client.rpc.SerializationException;
import com.google.gwt.user.client.rpc.SerializationStreamReader;
import com.google.gwt.user.client.rpc.SerializationStreamWriter;
import com.google.gwt.user.client.rpc.core.java.util.Collection_CustomFieldSerializerBase;
import java.util.ArrayList;
import java.util.List;
/**
* This class implements the client-side GWT serialization of
* {@link ImmutableAsList}.
*
* @author Hayward Chan
*/
public class ImmutableAsList_CustomFieldSerializer {
public static void deserialize(SerializationStreamReader reader,
RegularImmutableList<?> instance) {
}
public static ImmutableAsList<Object> instantiate(
SerializationStreamReader reader) throws SerializationException {
List<Object> elements = new ArrayList<Object>();
Collection_CustomFieldSerializerBase.deserialize(reader, elements);
return new ImmutableAsList<Object>(elements);
}
public static void serialize(SerializationStreamWriter writer,
ImmutableAsList<?> instance) throws SerializationException {
Collection_CustomFieldSerializerBase.serialize(writer, instance);
}
}
| Java |
/*
* Copyright (C) 2007 The Guava Authors
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package com.google.common.collect;
import static com.google.common.base.Preconditions.checkArgument;
import static com.google.common.base.Preconditions.checkNotNull;
import com.google.common.annotations.Beta;
import com.google.common.annotations.GwtCompatible;
import com.google.common.base.Function;
import com.google.common.base.Objects;
import com.google.common.base.Preconditions;
import com.google.common.base.Predicate;
import com.google.common.base.Predicates;
import com.google.common.collect.Collections2.FilteredCollection;
import com.google.common.math.IntMath;
import java.io.Serializable;
import java.util.AbstractSet;
import java.util.Arrays;
import java.util.Collection;
import java.util.Collections;
import java.util.Comparator;
import java.util.EnumSet;
import java.util.HashSet;
import java.util.Iterator;
import java.util.LinkedHashSet;
import java.util.List;
import java.util.Map;
import java.util.NoSuchElementException;
import java.util.Set;
import java.util.SortedSet;
import java.util.TreeSet;
import javax.annotation.Nullable;
/**
* Static utility methods pertaining to {@link Set} instances. Also see this
* class's counterparts {@link Lists} and {@link Maps}.
*
* <p>See the Guava User Guide article on <a href=
* "http://code.google.com/p/guava-libraries/wiki/CollectionUtilitiesExplained#Sets">
* {@code Sets}</a>.
*
* @author Kevin Bourrillion
* @author Jared Levy
* @author Chris Povirk
* @since 2.0 (imported from Google Collections Library)
*/
@GwtCompatible(emulated = true)
public final class Sets {
private Sets() {}
/**
* Returns an immutable set instance containing the given enum elements.
* Internally, the returned set will be backed by an {@link EnumSet}.
*
* <p>The iteration order of the returned set follows the enum's iteration
* order, not the order in which the elements are provided to the method.
*
* @param anElement one of the elements the set should contain
* @param otherElements the rest of the elements the set should contain
* @return an immutable set containing those elements, minus duplicates
*/
// http://code.google.com/p/google-web-toolkit/issues/detail?id=3028
@GwtCompatible(serializable = true)
public static <E extends Enum<E>> ImmutableSet<E> immutableEnumSet(
E anElement, E... otherElements) {
return new ImmutableEnumSet<E>(EnumSet.of(anElement, otherElements));
}
/**
* Returns an immutable set instance containing the given enum elements.
* Internally, the returned set will be backed by an {@link EnumSet}.
*
* <p>The iteration order of the returned set follows the enum's iteration
* order, not the order in which the elements appear in the given collection.
*
* @param elements the elements, all of the same {@code enum} type, that the
* set should contain
* @return an immutable set containing those elements, minus duplicates
*/
// http://code.google.com/p/google-web-toolkit/issues/detail?id=3028
@GwtCompatible(serializable = true)
public static <E extends Enum<E>> ImmutableSet<E> immutableEnumSet(
Iterable<E> elements) {
Iterator<E> iterator = elements.iterator();
if (!iterator.hasNext()) {
return ImmutableSet.of();
}
if (elements instanceof EnumSet) {
EnumSet<E> enumSetClone = EnumSet.copyOf((EnumSet<E>) elements);
return new ImmutableEnumSet<E>(enumSetClone);
}
E first = iterator.next();
EnumSet<E> set = EnumSet.of(first);
while (iterator.hasNext()) {
set.add(iterator.next());
}
return new ImmutableEnumSet<E>(set);
}
/**
* Returns a new {@code EnumSet} instance containing the given elements.
* Unlike {@link EnumSet#copyOf(Collection)}, this method does not produce an
* exception on an empty collection, and it may be called on any iterable, not
* just a {@code Collection}.
*/
public static <E extends Enum<E>> EnumSet<E> newEnumSet(Iterable<E> iterable,
Class<E> elementType) {
/*
* TODO(cpovirk): noneOf() and addAll() will both throw
* NullPointerExceptions when appropriate. However, NullPointerTester will
* fail on this method because it passes in Class.class instead of an enum
* type. This means that, when iterable is null but elementType is not,
* noneOf() will throw a ClassCastException before addAll() has a chance to
* throw a NullPointerException. NullPointerTester considers this a failure.
* Ideally the test would be fixed, but it would require a special case for
* Class<E> where E extends Enum. Until that happens (if ever), leave
* checkNotNull() here. For now, contemplate the irony that checking
* elementType, the problem argument, is harmful, while checking iterable,
* the innocent bystander, is effective.
*/
checkNotNull(iterable);
EnumSet<E> set = EnumSet.noneOf(elementType);
Iterables.addAll(set, iterable);
return set;
}
// HashSet
/**
* Creates a <i>mutable</i>, empty {@code HashSet} instance.
*
* <p><b>Note:</b> if mutability is not required, use {@link
* ImmutableSet#of()} instead.
*
* <p><b>Note:</b> if {@code E} is an {@link Enum} type, use {@link
* EnumSet#noneOf} instead.
*
* @return a new, empty {@code HashSet}
*/
public static <E> HashSet<E> newHashSet() {
return new HashSet<E>();
}
/**
* Creates a <i>mutable</i> {@code HashSet} instance containing the given
* elements in unspecified order.
*
* <p><b>Note:</b> if mutability is not required and the elements are
* non-null, use an overload of {@link ImmutableSet#of()} (for varargs) or
* {@link ImmutableSet#copyOf(Object[])} (for an array) instead.
*
* <p><b>Note:</b> if {@code E} is an {@link Enum} type, use {@link
* EnumSet#of(Enum, Enum[])} instead.
*
* @param elements the elements that the set should contain
* @return a new {@code HashSet} containing those elements (minus duplicates)
*/
public static <E> HashSet<E> newHashSet(E... elements) {
HashSet<E> set = newHashSetWithExpectedSize(elements.length);
Collections.addAll(set, elements);
return set;
}
/**
* Creates a {@code HashSet} instance, with a high enough "initial capacity"
* that it <i>should</i> hold {@code expectedSize} elements without growth.
* This behavior cannot be broadly guaranteed, but it is observed to be true
* for OpenJDK 1.6. It also can't be guaranteed that the method isn't
* inadvertently <i>oversizing</i> the returned set.
*
* @param expectedSize the number of elements you expect to add to the
* returned set
* @return a new, empty {@code HashSet} with enough capacity to hold {@code
* expectedSize} elements without resizing
* @throws IllegalArgumentException if {@code expectedSize} is negative
*/
public static <E> HashSet<E> newHashSetWithExpectedSize(int expectedSize) {
return new HashSet<E>(Maps.capacity(expectedSize));
}
/**
* Creates a <i>mutable</i> {@code HashSet} instance containing the given
* elements in unspecified order.
*
* <p><b>Note:</b> if mutability is not required and the elements are
* non-null, use {@link ImmutableSet#copyOf(Iterable)} instead.
*
* <p><b>Note:</b> if {@code E} is an {@link Enum} type, use
* {@link #newEnumSet(Iterable, Class)} instead.
*
* @param elements the elements that the set should contain
* @return a new {@code HashSet} containing those elements (minus duplicates)
*/
public static <E> HashSet<E> newHashSet(Iterable<? extends E> elements) {
return (elements instanceof Collection)
? new HashSet<E>(Collections2.cast(elements))
: newHashSet(elements.iterator());
}
/**
* Creates a <i>mutable</i> {@code HashSet} instance containing the given
* elements in unspecified order.
*
* <p><b>Note:</b> if mutability is not required and the elements are
* non-null, use {@link ImmutableSet#copyOf(Iterable)} instead.
*
* <p><b>Note:</b> if {@code E} is an {@link Enum} type, you should create an
* {@link EnumSet} instead.
*
* @param elements the elements that the set should contain
* @return a new {@code HashSet} containing those elements (minus duplicates)
*/
public static <E> HashSet<E> newHashSet(Iterator<? extends E> elements) {
HashSet<E> set = newHashSet();
while (elements.hasNext()) {
set.add(elements.next());
}
return set;
}
// LinkedHashSet
/**
* Creates a <i>mutable</i>, empty {@code LinkedHashSet} instance.
*
* <p><b>Note:</b> if mutability is not required, use {@link
* ImmutableSet#of()} instead.
*
* @return a new, empty {@code LinkedHashSet}
*/
public static <E> LinkedHashSet<E> newLinkedHashSet() {
return new LinkedHashSet<E>();
}
/**
* Creates a {@code LinkedHashSet} instance, with a high enough "initial
* capacity" that it <i>should</i> hold {@code expectedSize} elements without
* growth. This behavior cannot be broadly guaranteed, but it is observed to
* be true for OpenJDK 1.6. It also can't be guaranteed that the method isn't
* inadvertently <i>oversizing</i> the returned set.
*
* @param expectedSize the number of elements you expect to add to the
* returned set
* @return a new, empty {@code LinkedHashSet} with enough capacity to hold
* {@code expectedSize} elements without resizing
* @throws IllegalArgumentException if {@code expectedSize} is negative
* @since 11.0
*/
public static <E> LinkedHashSet<E> newLinkedHashSetWithExpectedSize(
int expectedSize) {
return new LinkedHashSet<E>(Maps.capacity(expectedSize));
}
/**
* Creates a <i>mutable</i> {@code LinkedHashSet} instance containing the
* given elements in order.
*
* <p><b>Note:</b> if mutability is not required and the elements are
* non-null, use {@link ImmutableSet#copyOf(Iterable)} instead.
*
* @param elements the elements that the set should contain, in order
* @return a new {@code LinkedHashSet} containing those elements (minus
* duplicates)
*/
public static <E> LinkedHashSet<E> newLinkedHashSet(
Iterable<? extends E> elements) {
if (elements instanceof Collection) {
return new LinkedHashSet<E>(Collections2.cast(elements));
}
LinkedHashSet<E> set = newLinkedHashSet();
for (E element : elements) {
set.add(element);
}
return set;
}
// TreeSet
/**
* Creates a <i>mutable</i>, empty {@code TreeSet} instance sorted by the
* natural sort ordering of its elements.
*
* <p><b>Note:</b> if mutability is not required, use {@link
* ImmutableSortedSet#of()} instead.
*
* @return a new, empty {@code TreeSet}
*/
public static <E extends Comparable> TreeSet<E> newTreeSet() {
return new TreeSet<E>();
}
/**
* Creates a <i>mutable</i> {@code TreeSet} instance containing the given
* elements sorted by their natural ordering.
*
* <p><b>Note:</b> if mutability is not required, use {@link
* ImmutableSortedSet#copyOf(Iterable)} instead.
*
* <p><b>Note:</b> If {@code elements} is a {@code SortedSet} with an explicit
* comparator, this method has different behavior than
* {@link TreeSet#TreeSet(SortedSet)}, which returns a {@code TreeSet} with
* that comparator.
*
* @param elements the elements that the set should contain
* @return a new {@code TreeSet} containing those elements (minus duplicates)
*/
public static <E extends Comparable> TreeSet<E> newTreeSet(
Iterable<? extends E> elements) {
TreeSet<E> set = newTreeSet();
for (E element : elements) {
set.add(element);
}
return set;
}
/**
* Creates a <i>mutable</i>, empty {@code TreeSet} instance with the given
* comparator.
*
* <p><b>Note:</b> if mutability is not required, use {@code
* ImmutableSortedSet.orderedBy(comparator).build()} instead.
*
* @param comparator the comparator to use to sort the set
* @return a new, empty {@code TreeSet}
* @throws NullPointerException if {@code comparator} is null
*/
public static <E> TreeSet<E> newTreeSet(Comparator<? super E> comparator) {
return new TreeSet<E>(checkNotNull(comparator));
}
/**
* Creates an empty {@code Set} that uses identity to determine equality. It
* compares object references, instead of calling {@code equals}, to
* determine whether a provided object matches an element in the set. For
* example, {@code contains} returns {@code false} when passed an object that
* equals a set member, but isn't the same instance. This behavior is similar
* to the way {@code IdentityHashMap} handles key lookups.
*
* @since 8.0
*/
public static <E> Set<E> newIdentityHashSet() {
return Sets.newSetFromMap(Maps.<E, Boolean>newIdentityHashMap());
}
/**
* Creates an {@code EnumSet} consisting of all enum values that are not in
* the specified collection. If the collection is an {@link EnumSet}, this
* method has the same behavior as {@link EnumSet#complementOf}. Otherwise,
* the specified collection must contain at least one element, in order to
* determine the element type. If the collection could be empty, use
* {@link #complementOf(Collection, Class)} instead of this method.
*
* @param collection the collection whose complement should be stored in the
* enum set
* @return a new, modifiable {@code EnumSet} containing all values of the enum
* that aren't present in the given collection
* @throws IllegalArgumentException if {@code collection} is not an
* {@code EnumSet} instance and contains no elements
*/
public static <E extends Enum<E>> EnumSet<E> complementOf(
Collection<E> collection) {
if (collection instanceof EnumSet) {
return EnumSet.complementOf((EnumSet<E>) collection);
}
checkArgument(!collection.isEmpty(),
"collection is empty; use the other version of this method");
Class<E> type = collection.iterator().next().getDeclaringClass();
return makeComplementByHand(collection, type);
}
/**
* Creates an {@code EnumSet} consisting of all enum values that are not in
* the specified collection. This is equivalent to
* {@link EnumSet#complementOf}, but can act on any input collection, as long
* as the elements are of enum type.
*
* @param collection the collection whose complement should be stored in the
* {@code EnumSet}
* @param type the type of the elements in the set
* @return a new, modifiable {@code EnumSet} initially containing all the
* values of the enum not present in the given collection
*/
public static <E extends Enum<E>> EnumSet<E> complementOf(
Collection<E> collection, Class<E> type) {
checkNotNull(collection);
return (collection instanceof EnumSet)
? EnumSet.complementOf((EnumSet<E>) collection)
: makeComplementByHand(collection, type);
}
private static <E extends Enum<E>> EnumSet<E> makeComplementByHand(
Collection<E> collection, Class<E> type) {
EnumSet<E> result = EnumSet.allOf(type);
result.removeAll(collection);
return result;
}
/*
* Regarding newSetForMap() and SetFromMap:
*
* Written by Doug Lea with assistance from members of JCP JSR-166
* Expert Group and released to the public domain, as explained at
* http://creativecommons.org/licenses/publicdomain
*/
/**
* Returns a set backed by the specified map. The resulting set displays
* the same ordering, concurrency, and performance characteristics as the
* backing map. In essence, this factory method provides a {@link Set}
* implementation corresponding to any {@link Map} implementation. There is no
* need to use this method on a {@link Map} implementation that already has a
* corresponding {@link Set} implementation (such as {@link java.util.HashMap}
* or {@link java.util.TreeMap}).
*
* <p>Each method invocation on the set returned by this method results in
* exactly one method invocation on the backing map or its {@code keySet}
* view, with one exception. The {@code addAll} method is implemented as a
* sequence of {@code put} invocations on the backing map.
*
* <p>The specified map must be empty at the time this method is invoked,
* and should not be accessed directly after this method returns. These
* conditions are ensured if the map is created empty, passed directly
* to this method, and no reference to the map is retained, as illustrated
* in the following code fragment: <pre> {@code
*
* Set<Object> identityHashSet = Sets.newSetFromMap(
* new IdentityHashMap<Object, Boolean>());}</pre>
*
* This method has the same behavior as the JDK 6 method
* {@code Collections.newSetFromMap()}. The returned set is serializable if
* the backing map is.
*
* @param map the backing map
* @return the set backed by the map
* @throws IllegalArgumentException if {@code map} is not empty
*/
public static <E> Set<E> newSetFromMap(Map<E, Boolean> map) {
return new SetFromMap<E>(map);
}
private static class SetFromMap<E> extends AbstractSet<E>
implements Set<E>, Serializable {
private final Map<E, Boolean> m; // The backing map
private transient Set<E> s; // Its keySet
SetFromMap(Map<E, Boolean> map) {
checkArgument(map.isEmpty(), "Map is non-empty");
m = map;
s = map.keySet();
}
@Override public void clear() {
m.clear();
}
@Override public int size() {
return m.size();
}
@Override public boolean isEmpty() {
return m.isEmpty();
}
@Override public boolean contains(Object o) {
return m.containsKey(o);
}
@Override public boolean remove(Object o) {
return m.remove(o) != null;
}
@Override public boolean add(E e) {
return m.put(e, Boolean.TRUE) == null;
}
@Override public Iterator<E> iterator() {
return s.iterator();
}
@Override public Object[] toArray() {
return s.toArray();
}
@Override public <T> T[] toArray(T[] a) {
return s.toArray(a);
}
@Override public String toString() {
return s.toString();
}
@Override public int hashCode() {
return s.hashCode();
}
@Override public boolean equals(@Nullable Object object) {
return this == object || this.s.equals(object);
}
@Override public boolean containsAll(Collection<?> c) {
return s.containsAll(c);
}
@Override public boolean removeAll(Collection<?> c) {
return s.removeAll(c);
}
@Override public boolean retainAll(Collection<?> c) {
return s.retainAll(c);
}
// addAll is the only inherited implementation
}
/**
* An unmodifiable view of a set which may be backed by other sets; this view
* will change as the backing sets do. Contains methods to copy the data into
* a new set which will then remain stable. There is usually no reason to
* retain a reference of type {@code SetView}; typically, you either use it
* as a plain {@link Set}, or immediately invoke {@link #immutableCopy} or
* {@link #copyInto} and forget the {@code SetView} itself.
*
* @since 2.0 (imported from Google Collections Library)
*/
public abstract static class SetView<E> extends AbstractSet<E> {
private SetView() {} // no subclasses but our own
/**
* Returns an immutable copy of the current contents of this set view.
* Does not support null elements.
*
* <p><b>Warning:</b> this may have unexpected results if a backing set of
* this view uses a nonstandard notion of equivalence, for example if it is
* a {@link TreeSet} using a comparator that is inconsistent with {@link
* Object#equals(Object)}.
*/
public ImmutableSet<E> immutableCopy() {
return ImmutableSet.copyOf(this);
}
/**
* Copies the current contents of this set view into an existing set. This
* method has equivalent behavior to {@code set.addAll(this)}, assuming that
* all the sets involved are based on the same notion of equivalence.
*
* @return a reference to {@code set}, for convenience
*/
// Note: S should logically extend Set<? super E> but can't due to either
// some javac bug or some weirdness in the spec, not sure which.
public <S extends Set<E>> S copyInto(S set) {
set.addAll(this);
return set;
}
}
/**
* Returns an unmodifiable <b>view</b> of the union of two sets. The returned
* set contains all elements that are contained in either backing set.
* Iterating over the returned set iterates first over all the elements of
* {@code set1}, then over each element of {@code set2}, in order, that is not
* contained in {@code set1}.
*
* <p>Results are undefined if {@code set1} and {@code set2} are sets based on
* different equivalence relations (as {@link HashSet}, {@link TreeSet}, and
* the {@link Map#keySet} of an {@code IdentityHashMap} all are).
*
* <p><b>Note:</b> The returned view performs better when {@code set1} is the
* smaller of the two sets. If you have reason to believe one of your sets
* will generally be smaller than the other, pass it first.
*/
public static <E> SetView<E> union(
final Set<? extends E> set1, final Set<? extends E> set2) {
checkNotNull(set1, "set1");
checkNotNull(set2, "set2");
final Set<? extends E> set2minus1 = difference(set2, set1);
return new SetView<E>() {
@Override public int size() {
return set1.size() + set2minus1.size();
}
@Override public boolean isEmpty() {
return set1.isEmpty() && set2.isEmpty();
}
@Override public Iterator<E> iterator() {
return Iterators.unmodifiableIterator(
Iterators.concat(set1.iterator(), set2minus1.iterator()));
}
@Override public boolean contains(Object object) {
return set1.contains(object) || set2.contains(object);
}
@Override public <S extends Set<E>> S copyInto(S set) {
set.addAll(set1);
set.addAll(set2);
return set;
}
@Override public ImmutableSet<E> immutableCopy() {
return new ImmutableSet.Builder<E>()
.addAll(set1).addAll(set2).build();
}
};
}
/**
* Returns an unmodifiable <b>view</b> of the intersection of two sets. The
* returned set contains all elements that are contained by both backing sets.
* The iteration order of the returned set matches that of {@code set1}.
*
* <p>Results are undefined if {@code set1} and {@code set2} are sets based
* on different equivalence relations (as {@code HashSet}, {@code TreeSet},
* and the keySet of an {@code IdentityHashMap} all are).
*
* <p><b>Note:</b> The returned view performs slightly better when {@code
* set1} is the smaller of the two sets. If you have reason to believe one of
* your sets will generally be smaller than the other, pass it first.
* Unfortunately, since this method sets the generic type of the returned set
* based on the type of the first set passed, this could in rare cases force
* you to make a cast, for example: <pre> {@code
*
* Set<Object> aFewBadObjects = ...
* Set<String> manyBadStrings = ...
*
* // impossible for a non-String to be in the intersection
* SuppressWarnings("unchecked")
* Set<String> badStrings = (Set) Sets.intersection(
* aFewBadObjects, manyBadStrings);}</pre>
*
* This is unfortunate, but should come up only very rarely.
*/
public static <E> SetView<E> intersection(
final Set<E> set1, final Set<?> set2) {
checkNotNull(set1, "set1");
checkNotNull(set2, "set2");
final Predicate<Object> inSet2 = Predicates.in(set2);
return new SetView<E>() {
@Override public Iterator<E> iterator() {
return Iterators.filter(set1.iterator(), inSet2);
}
@Override public int size() {
return Iterators.size(iterator());
}
@Override public boolean isEmpty() {
return !iterator().hasNext();
}
@Override public boolean contains(Object object) {
return set1.contains(object) && set2.contains(object);
}
@Override public boolean containsAll(Collection<?> collection) {
return set1.containsAll(collection)
&& set2.containsAll(collection);
}
};
}
/**
* Returns an unmodifiable <b>view</b> of the difference of two sets. The
* returned set contains all elements that are contained by {@code set1} and
* not contained by {@code set2}. {@code set2} may also contain elements not
* present in {@code set1}; these are simply ignored. The iteration order of
* the returned set matches that of {@code set1}.
*
* <p>Results are undefined if {@code set1} and {@code set2} are sets based
* on different equivalence relations (as {@code HashSet}, {@code TreeSet},
* and the keySet of an {@code IdentityHashMap} all are).
*/
public static <E> SetView<E> difference(
final Set<E> set1, final Set<?> set2) {
checkNotNull(set1, "set1");
checkNotNull(set2, "set2");
final Predicate<Object> notInSet2 = Predicates.not(Predicates.in(set2));
return new SetView<E>() {
@Override public Iterator<E> iterator() {
return Iterators.filter(set1.iterator(), notInSet2);
}
@Override public int size() {
return Iterators.size(iterator());
}
@Override public boolean isEmpty() {
return set2.containsAll(set1);
}
@Override public boolean contains(Object element) {
return set1.contains(element) && !set2.contains(element);
}
};
}
/**
* Returns an unmodifiable <b>view</b> of the symmetric difference of two
* sets. The returned set contains all elements that are contained in either
* {@code set1} or {@code set2} but not in both. The iteration order of the
* returned set is undefined.
*
* <p>Results are undefined if {@code set1} and {@code set2} are sets based
* on different equivalence relations (as {@code HashSet}, {@code TreeSet},
* and the keySet of an {@code IdentityHashMap} all are).
*
* @since 3.0
*/
public static <E> SetView<E> symmetricDifference(
Set<? extends E> set1, Set<? extends E> set2) {
checkNotNull(set1, "set1");
checkNotNull(set2, "set2");
// TODO(kevinb): Replace this with a more efficient implementation
return difference(union(set1, set2), intersection(set1, set2));
}
/**
* Returns the elements of {@code unfiltered} that satisfy a predicate. The
* returned set is a live view of {@code unfiltered}; changes to one affect
* the other.
*
* <p>The resulting set's iterator does not support {@code remove()}, but all
* other set methods are supported. When given an element that doesn't satisfy
* the predicate, the set's {@code add()} and {@code addAll()} methods throw
* an {@link IllegalArgumentException}. When methods such as {@code
* removeAll()} and {@code clear()} are called on the filtered set, only
* elements that satisfy the filter will be removed from the underlying set.
*
* <p>The returned set isn't threadsafe or serializable, even if
* {@code unfiltered} is.
*
* <p>Many of the filtered set's methods, such as {@code size()}, iterate
* across every element in the underlying set and determine which elements
* satisfy the filter. When a live view is <i>not</i> needed, it may be faster
* to copy {@code Iterables.filter(unfiltered, predicate)} and use the copy.
*
* <p><b>Warning:</b> {@code predicate} must be <i>consistent with equals</i>,
* as documented at {@link Predicate#apply}. Do not provide a predicate such
* as {@code Predicates.instanceOf(ArrayList.class)}, which is inconsistent
* with equals. (See {@link Iterables#filter(Iterable, Class)} for related
* functionality.)
*/
// TODO(kevinb): how to omit that last sentence when building GWT javadoc?
public static <E> Set<E> filter(
Set<E> unfiltered, Predicate<? super E> predicate) {
if (unfiltered instanceof SortedSet) {
return filter((SortedSet<E>) unfiltered, predicate);
}
if (unfiltered instanceof FilteredSet) {
// Support clear(), removeAll(), and retainAll() when filtering a filtered
// collection.
FilteredSet<E> filtered = (FilteredSet<E>) unfiltered;
Predicate<E> combinedPredicate
= Predicates.<E>and(filtered.predicate, predicate);
return new FilteredSet<E>(
(Set<E>) filtered.unfiltered, combinedPredicate);
}
return new FilteredSet<E>(
checkNotNull(unfiltered), checkNotNull(predicate));
}
private static class FilteredSet<E> extends FilteredCollection<E>
implements Set<E> {
FilteredSet(Set<E> unfiltered, Predicate<? super E> predicate) {
super(unfiltered, predicate);
}
@Override public boolean equals(@Nullable Object object) {
return equalsImpl(this, object);
}
@Override public int hashCode() {
return hashCodeImpl(this);
}
}
/**
* Returns the elements of a {@code SortedSet}, {@code unfiltered}, that
* satisfy a predicate. The returned set is a live view of {@code unfiltered};
* changes to one affect the other.
*
* <p>The resulting set's iterator does not support {@code remove()}, but all
* other set methods are supported. When given an element that doesn't satisfy
* the predicate, the set's {@code add()} and {@code addAll()} methods throw
* an {@link IllegalArgumentException}. When methods such as
* {@code removeAll()} and {@code clear()} are called on the filtered set,
* only elements that satisfy the filter will be removed from the underlying
* set.
*
* <p>The returned set isn't threadsafe or serializable, even if
* {@code unfiltered} is.
*
* <p>Many of the filtered set's methods, such as {@code size()}, iterate across
* every element in the underlying set and determine which elements satisfy
* the filter. When a live view is <i>not</i> needed, it may be faster to copy
* {@code Iterables.filter(unfiltered, predicate)} and use the copy.
*
* <p><b>Warning:</b> {@code predicate} must be <i>consistent with equals</i>,
* as documented at {@link Predicate#apply}. Do not provide a predicate such as
* {@code Predicates.instanceOf(ArrayList.class)}, which is inconsistent with
* equals. (See {@link Iterables#filter(Iterable, Class)} for related
* functionality.)
*
* @since 11.0
*/
@Beta
@SuppressWarnings("unchecked")
public static <E> SortedSet<E> filter(
SortedSet<E> unfiltered, Predicate<? super E> predicate) {
if (unfiltered instanceof FilteredSet) {
// Support clear(), removeAll(), and retainAll() when filtering a filtered
// collection.
FilteredSet<E> filtered = (FilteredSet<E>) unfiltered;
Predicate<E> combinedPredicate
= Predicates.<E>and(filtered.predicate, predicate);
return new FilteredSortedSet<E>(
(SortedSet<E>) filtered.unfiltered, combinedPredicate);
}
return new FilteredSortedSet<E>(
checkNotNull(unfiltered), checkNotNull(predicate));
}
private static class FilteredSortedSet<E> extends FilteredCollection<E>
implements SortedSet<E> {
FilteredSortedSet(SortedSet<E> unfiltered, Predicate<? super E> predicate) {
super(unfiltered, predicate);
}
@Override public boolean equals(@Nullable Object object) {
return equalsImpl(this, object);
}
@Override public int hashCode() {
return hashCodeImpl(this);
}
@Override
public Comparator<? super E> comparator() {
return ((SortedSet<E>) unfiltered).comparator();
}
@Override
public SortedSet<E> subSet(E fromElement, E toElement) {
return new FilteredSortedSet<E>(((SortedSet<E>) unfiltered).subSet(fromElement, toElement),
predicate);
}
@Override
public SortedSet<E> headSet(E toElement) {
return new FilteredSortedSet<E>(((SortedSet<E>) unfiltered).headSet(toElement), predicate);
}
@Override
public SortedSet<E> tailSet(E fromElement) {
return new FilteredSortedSet<E>(((SortedSet<E>) unfiltered).tailSet(fromElement), predicate);
}
@Override
public E first() {
return iterator().next();
}
@Override
public E last() {
SortedSet<E> sortedUnfiltered = (SortedSet<E>) unfiltered;
while (true) {
E element = sortedUnfiltered.last();
if (predicate.apply(element)) {
return element;
}
sortedUnfiltered = sortedUnfiltered.headSet(element);
}
}
}
/**
* Returns every possible list that can be formed by choosing one element
* from each of the given sets in order; the "n-ary
* <a href="http://en.wikipedia.org/wiki/Cartesian_product">Cartesian
* product</a>" of the sets. For example: <pre> {@code
*
* Sets.cartesianProduct(ImmutableList.of(
* ImmutableSet.of(1, 2),
* ImmutableSet.of("A", "B", "C")))}</pre>
*
* returns a set containing six lists:
*
* <ul>
* <li>{@code ImmutableList.of(1, "A")}
* <li>{@code ImmutableList.of(1, "B")}
* <li>{@code ImmutableList.of(1, "C")}
* <li>{@code ImmutableList.of(2, "A")}
* <li>{@code ImmutableList.of(2, "B")}
* <li>{@code ImmutableList.of(2, "C")}
* </ul>
*
* The order in which these lists are returned is not guaranteed, however the
* position of an element inside a tuple always corresponds to the position of
* the set from which it came in the input list. Note that if any input set is
* empty, the Cartesian product will also be empty. If no sets at all are
* provided (an empty list), the resulting Cartesian product has one element,
* an empty list (counter-intuitive, but mathematically consistent).
*
* <p><i>Performance notes:</i> while the cartesian product of sets of size
* {@code m, n, p} is a set of size {@code m x n x p}, its actual memory
* consumption is much smaller. When the cartesian set is constructed, the
* input sets are merely copied. Only as the resulting set is iterated are the
* individual lists created, and these are not retained after iteration.
*
* @param sets the sets to choose elements from, in the order that
* the elements chosen from those sets should appear in the resulting
* lists
* @param <B> any common base class shared by all axes (often just {@link
* Object})
* @return the Cartesian product, as an immutable set containing immutable
* lists
* @throws NullPointerException if {@code sets}, any one of the {@code sets},
* or any element of a provided set is null
* @since 2.0
*/
public static <B> Set<List<B>> cartesianProduct(
List<? extends Set<? extends B>> sets) {
for (Set<? extends B> set : sets) {
if (set.isEmpty()) {
return ImmutableSet.of();
}
}
CartesianSet<B> cartesianSet = new CartesianSet<B>(sets);
return cartesianSet;
}
/**
* Returns every possible list that can be formed by choosing one element
* from each of the given sets in order; the "n-ary
* <a href="http://en.wikipedia.org/wiki/Cartesian_product">Cartesian
* product</a>" of the sets. For example: <pre> {@code
*
* Sets.cartesianProduct(
* ImmutableSet.of(1, 2),
* ImmutableSet.of("A", "B", "C"))}</pre>
*
* returns a set containing six lists:
*
* <ul>
* <li>{@code ImmutableList.of(1, "A")}
* <li>{@code ImmutableList.of(1, "B")}
* <li>{@code ImmutableList.of(1, "C")}
* <li>{@code ImmutableList.of(2, "A")}
* <li>{@code ImmutableList.of(2, "B")}
* <li>{@code ImmutableList.of(2, "C")}
* </ul>
*
* The order in which these lists are returned is not guaranteed, however the
* position of an element inside a tuple always corresponds to the position of
* the set from which it came in the input list. Note that if any input set is
* empty, the Cartesian product will also be empty. If no sets at all are
* provided, the resulting Cartesian product has one element, an empty list
* (counter-intuitive, but mathematically consistent).
*
* <p><i>Performance notes:</i> while the cartesian product of sets of size
* {@code m, n, p} is a set of size {@code m x n x p}, its actual memory
* consumption is much smaller. When the cartesian set is constructed, the
* input sets are merely copied. Only as the resulting set is iterated are the
* individual lists created, and these are not retained after iteration.
*
* @param sets the sets to choose elements from, in the order that
* the elements chosen from those sets should appear in the resulting
* lists
* @param <B> any common base class shared by all axes (often just {@link
* Object})
* @return the Cartesian product, as an immutable set containing immutable
* lists
* @throws NullPointerException if {@code sets}, any one of the {@code sets},
* or any element of a provided set is null
* @since 2.0
*/
public static <B> Set<List<B>> cartesianProduct(
Set<? extends B>... sets) {
return cartesianProduct(Arrays.asList(sets));
}
private static class CartesianSet<B> extends AbstractSet<List<B>> {
final ImmutableList<Axis> axes;
final int size;
CartesianSet(List<? extends Set<? extends B>> sets) {
int dividend = 1;
ImmutableList.Builder<Axis> builder = ImmutableList.builder();
try {
for (Set<? extends B> set : sets) {
Axis axis = new Axis(set, dividend);
builder.add(axis);
dividend = IntMath.checkedMultiply(dividend, axis.size());
}
} catch (ArithmeticException overflow) {
throw new IllegalArgumentException("cartesian product too big");
}
this.axes = builder.build();
size = dividend;
}
@Override public int size() {
return size;
}
@Override public UnmodifiableIterator<List<B>> iterator() {
return new UnmodifiableIterator<List<B>>() {
int index;
@Override
public boolean hasNext() {
return index < size;
}
@Override
public List<B> next() {
if (!hasNext()) {
throw new NoSuchElementException();
}
Object[] tuple = new Object[axes.size()];
for (int i = 0 ; i < tuple.length; i++) {
tuple[i] = axes.get(i).getForIndex(index);
}
index++;
@SuppressWarnings("unchecked") // only B's are put in here
List<B> result = (ImmutableList<B>) ImmutableList.copyOf(tuple);
return result;
}
};
}
@Override public boolean contains(Object element) {
if (!(element instanceof List<?>)) {
return false;
}
List<?> tuple = (List<?>) element;
int dimensions = axes.size();
if (tuple.size() != dimensions) {
return false;
}
for (int i = 0; i < dimensions; i++) {
if (!axes.get(i).contains(tuple.get(i))) {
return false;
}
}
return true;
}
@Override public boolean equals(@Nullable Object object) {
// Warning: this is broken if size() == 0, so it is critical that we
// substitute an empty ImmutableSet to the user in place of this
if (object instanceof CartesianSet) {
CartesianSet<?> that = (CartesianSet<?>) object;
return this.axes.equals(that.axes);
}
return super.equals(object);
}
@Override public int hashCode() {
// Warning: this is broken if size() == 0, so it is critical that we
// substitute an empty ImmutableSet to the user in place of this
// It's a weird formula, but tests prove it works.
int adjust = size - 1;
for (int i = 0; i < axes.size(); i++) {
adjust *= 31;
}
return axes.hashCode() + adjust;
}
private class Axis {
final ImmutableSet<? extends B> choices;
final ImmutableList<? extends B> choicesList;
final int dividend;
Axis(Set<? extends B> set, int dividend) {
choices = ImmutableSet.copyOf(set);
choicesList = choices.asList();
this.dividend = dividend;
}
int size() {
return choices.size();
}
B getForIndex(int index) {
return choicesList.get(index / dividend % size());
}
boolean contains(Object target) {
return choices.contains(target);
}
@Override public boolean equals(Object obj) {
if (obj instanceof CartesianSet.Axis) {
CartesianSet.Axis that = (CartesianSet.Axis) obj;
return this.choices.equals(that.choices);
// dividends must be equal or we wouldn't have gotten this far
}
return false;
}
@Override public int hashCode() {
// Because Axis instances are not exposed, we can
// opportunistically choose whatever bizarre formula happens
// to make CartesianSet.hashCode() as simple as possible.
return size / choices.size() * choices.hashCode();
}
}
}
/**
* Returns the set of all possible subsets of {@code set}. For example,
* {@code powerSet(ImmutableSet.of(1, 2))} returns the set {@code {{},
* {1}, {2}, {1, 2}}}.
*
* <p>Elements appear in these subsets in the same iteration order as they
* appeared in the input set. The order in which these subsets appear in the
* outer set is undefined. Note that the power set of the empty set is not the
* empty set, but a one-element set containing the empty set.
*
* <p>The returned set and its constituent sets use {@code equals} to decide
* whether two elements are identical, even if the input set uses a different
* concept of equivalence.
*
* <p><i>Performance notes:</i> while the power set of a set with size {@code
* n} is of size {@code 2^n}, its memory usage is only {@code O(n)}. When the
* power set is constructed, the input set is merely copied. Only as the
* power set is iterated are the individual subsets created, and these subsets
* themselves occupy only a few bytes of memory regardless of their size.
*
* @param set the set of elements to construct a power set from
* @return the power set, as an immutable set of immutable sets
* @throws IllegalArgumentException if {@code set} has more than 30 unique
* elements (causing the power set size to exceed the {@code int} range)
* @throws NullPointerException if {@code set} is or contains {@code null}
* @see <a href="http://en.wikipedia.org/wiki/Power_set">Power set article at
* Wikipedia</a>
* @since 4.0
*/
@GwtCompatible(serializable = false)
public static <E> Set<Set<E>> powerSet(Set<E> set) {
ImmutableSet<E> input = ImmutableSet.copyOf(set);
checkArgument(input.size() <= 30,
"Too many elements to create power set: %s > 30", input.size());
return new PowerSet<E>(input);
}
private static final class PowerSet<E> extends AbstractSet<Set<E>> {
final ImmutableSet<E> inputSet;
final ImmutableList<E> inputList;
final int powerSetSize;
PowerSet(ImmutableSet<E> input) {
this.inputSet = input;
this.inputList = input.asList();
this.powerSetSize = 1 << input.size();
}
@Override public int size() {
return powerSetSize;
}
@Override public boolean isEmpty() {
return false;
}
@Override public Iterator<Set<E>> iterator() {
return new AbstractIndexedListIterator<Set<E>>(powerSetSize) {
@Override protected Set<E> get(final int setBits) {
return new AbstractSet<E>() {
@Override public int size() {
return Integer.bitCount(setBits);
}
@Override public Iterator<E> iterator() {
return new BitFilteredSetIterator<E>(inputList, setBits);
}
};
}
};
}
private static final class BitFilteredSetIterator<E>
extends UnmodifiableIterator<E> {
final ImmutableList<E> input;
int remainingSetBits;
BitFilteredSetIterator(ImmutableList<E> input, int allSetBits) {
this.input = input;
this.remainingSetBits = allSetBits;
}
@Override public boolean hasNext() {
return remainingSetBits != 0;
}
@Override public E next() {
int index = Integer.numberOfTrailingZeros(remainingSetBits);
if (index == 32) {
throw new NoSuchElementException();
}
int currentElementMask = 1 << index;
remainingSetBits &= ~currentElementMask;
return input.get(index);
}
}
@Override public boolean contains(@Nullable Object obj) {
if (obj instanceof Set) {
Set<?> set = (Set<?>) obj;
return inputSet.containsAll(set);
}
return false;
}
@Override public boolean equals(@Nullable Object obj) {
if (obj instanceof PowerSet) {
PowerSet<?> that = (PowerSet<?>) obj;
return inputSet.equals(that.inputSet);
}
return super.equals(obj);
}
@Override public int hashCode() {
/*
* The sum of the sums of the hash codes in each subset is just the sum of
* each input element's hash code times the number of sets that element
* appears in. Each element appears in exactly half of the 2^n sets, so:
*/
return inputSet.hashCode() << (inputSet.size() - 1);
}
@Override public String toString() {
return "powerSet(" + inputSet + ")";
}
}
/**
* An implementation for {@link Set#hashCode()}.
*/
static int hashCodeImpl(Set<?> s) {
int hashCode = 0;
for (Object o : s) {
hashCode += o != null ? o.hashCode() : 0;
}
return hashCode;
}
/**
* An implementation for {@link Set#equals(Object)}.
*/
static boolean equalsImpl(Set<?> s, @Nullable Object object){
if (s == object) {
return true;
}
if (object instanceof Set) {
Set<?> o = (Set<?>) object;
try {
return s.size() == o.size() && s.containsAll(o);
} catch (NullPointerException ignored) {
return false;
} catch (ClassCastException ignored) {
return false;
}
}
return false;
}
/**
* Creates a view of Set<B> for a Set<A>, given a bijection between A and B.
* (Modelled for now as InvertibleFunction<A, B>, can't be Converter<A, B>
* because that's not in Guava, though both designs are less than optimal).
* Note that the bijection is treated as undefined for values not in the
* given Set<A> - it doesn't have to define a true bijection for those.
*
* <p>Note that the returned Set's contains method is unsafe -
* you *must* pass an instance of B to it, since the bijection
* can only invert B's (not any Object) back to A, so we can
* then delegate the call to the original Set<A>.
*/
static <A, B> Set<B> transform(
Set<A> set, InvertibleFunction<A, B> bijection) {
return new TransformedSet<A, B>(
Preconditions.checkNotNull(set, "set"),
Preconditions.checkNotNull(bijection, "bijection")
);
}
/**
* Stop-gap measure since there is no bijection related type in Guava.
*/
abstract static class InvertibleFunction<A, B> implements Function<A, B> {
abstract A invert(B b);
public InvertibleFunction<B, A> inverse() {
return new InvertibleFunction<B, A>() {
@Override public A apply(B b) {
return InvertibleFunction.this.invert(b);
}
@Override B invert(A a) {
return InvertibleFunction.this.apply(a);
}
// Not required per se, but just for good karma.
@Override public InvertibleFunction<A, B> inverse() {
return InvertibleFunction.this;
}
};
}
}
private static class TransformedSet<A, B> extends AbstractSet<B> {
final Set<A> delegate;
final InvertibleFunction<A, B> bijection;
TransformedSet(Set<A> delegate, InvertibleFunction<A, B> bijection) {
this.delegate = delegate;
this.bijection = bijection;
}
@Override public Iterator<B> iterator() {
return Iterators.transform(delegate.iterator(), bijection);
}
@Override public int size() {
return delegate.size();
}
@SuppressWarnings("unchecked") // unsafe, passed object *must* be B
@Override public boolean contains(Object o) {
B b = (B) o;
A a = bijection.invert(b);
/*
* Mathematically, Converter<A, B> defines a bijection between ALL A's
* on ALL B's. Here we concern ourselves with a subset
* of this relation: we only want the part that is defined by a *subset*
* of all A's (defined by that Set<A> delegate), and the image
* of *that* on B (which is this set). We don't care whether
* the converter is *not* a bijection for A's that are not in Set<A>
* or B's not in this Set<B>.
*
* We only want to return true if and only f the user passes a B instance
* that is contained in precisely in the image of Set<A>.
*
* The first test is whether the inverse image of this B is indeed
* in Set<A>. But we don't know whether that B belongs in this Set<B>
* or not; if not, the converter is free to return
* anything it wants, even an element of Set<A> (and this relationship
* is not part of the Set<A> <--> Set<B> bijection), and we must not
* be confused by that. So we have to do a final check to see if the
* image of that A is really equivalent to the passed B, which proves
* that the given B belongs indeed in the image of Set<A>.
*/
return delegate.contains(a) && Objects.equal(bijection.apply(a), o);
}
@Override public boolean add(B b) {
return delegate.add(bijection.invert(b));
}
@SuppressWarnings("unchecked") // unsafe, passed object *must* be B
@Override public boolean remove(Object o) {
return contains(o) && delegate.remove(bijection.invert((B) o));
}
@Override public void clear() {
delegate.clear();
}
}
/**
* Remove each element in an iterable from a set.
*/
static boolean removeAllImpl(Set<?> set, Iterable<?> iterable) {
// TODO(jlevy): Have ForwardingSet.standardRemoveAll() call this method.
boolean changed = false;
for (Object o : iterable) {
changed |= set.remove(o);
}
return changed;
}
}
| Java |
/*
* Copyright (C) 2008 The Guava Authors
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package com.google.common.collect;
/**
* Minimal GWT emulation of {@code com.google.common.collect.Platform}.
*
* <p><strong>This .java file should never be consumed by javac.</strong>
*
* @author Hayward Chan
*/
class Platform {
static <T> T[] clone(T[] array) {
return GwtPlatform.clone(array);
}
// TODO: Fix System.arraycopy in GWT so that it isn't necessary.
static void unsafeArrayCopy(
Object[] src, int srcPos, Object[] dest, int destPos, int length) {
for (int i = 0; i < length; i++) {
dest[destPos + i] = src[srcPos + i];
}
}
static <T> T[] newArray(Class<T> type, int length) {
throw new UnsupportedOperationException(
"Platform.newArray is not supported in GWT yet.");
}
static <T> T[] newArray(T[] reference, int length) {
return GwtPlatform.newArray(reference, length);
}
static MapMaker tryWeakKeys(MapMaker mapMaker) {
return mapMaker;
}
}
| Java |
/*
* Copyright (C) 2007 The Guava Authors
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package com.google.common.collect;
import static com.google.common.base.Preconditions.checkNotNull;
import com.google.common.annotations.GwtCompatible;
import java.util.Collection;
import java.util.Comparator;
import java.util.SortedMap;
import java.util.SortedSet;
import java.util.TreeMap;
import java.util.TreeSet;
/**
* Implementation of {@code Multimap} whose keys and values are ordered by
* their natural ordering or by supplied comparators. In all cases, this
* implementation uses {@link Comparable#compareTo} or {@link
* Comparator#compare} instead of {@link Object#equals} to determine
* equivalence of instances.
*
* <p><b>Warning:</b> The comparators or comparables used must be <i>consistent
* with equals</i> as explained by the {@link Comparable} class specification.
* Otherwise, the resulting multiset will violate the general contract of {@link
* SetMultimap}, which it is specified in terms of {@link Object#equals}.
*
* <p>The collections returned by {@code keySet} and {@code asMap} iterate
* through the keys according to the key comparator ordering or the natural
* ordering of the keys. Similarly, {@code get}, {@code removeAll}, and {@code
* replaceValues} return collections that iterate through the values according
* to the value comparator ordering or the natural ordering of the values. The
* collections generated by {@code entries}, {@code keys}, and {@code values}
* iterate across the keys according to the above key ordering, and for each
* key they iterate across the values according to the value ordering.
*
* <p>The multimap does not store duplicate key-value pairs. Adding a new
* key-value pair equal to an existing key-value pair has no effect.
*
* <p>Null keys and values are permitted (provided, of course, that the
* respective comparators support them). All optional multimap methods are
* supported, and all returned views are modifiable.
*
* <p>This class is not threadsafe when any concurrent operations update the
* multimap. Concurrent read operations will work correctly. To allow concurrent
* update operations, wrap your multimap with a call to {@link
* Multimaps#synchronizedSortedSetMultimap}.
*
* <p>See the Guava User Guide article on <a href=
* "http://code.google.com/p/guava-libraries/wiki/NewCollectionTypesExplained#Multimap">
* {@code Multimap}</a>.
*
* @author Jared Levy
* @since 2.0 (imported from Google Collections Library)
*/
@GwtCompatible(serializable = true, emulated = true)
public class TreeMultimap<K, V> extends AbstractSortedSetMultimap<K, V> {
private transient Comparator<? super K> keyComparator;
private transient Comparator<? super V> valueComparator;
/**
* Creates an empty {@code TreeMultimap} ordered by the natural ordering of
* its keys and values.
*/
public static <K extends Comparable, V extends Comparable>
TreeMultimap<K, V> create() {
return new TreeMultimap<K, V>(Ordering.natural(), Ordering.natural());
}
/**
* Creates an empty {@code TreeMultimap} instance using explicit comparators.
* Neither comparator may be null; use {@link Ordering#natural()} to specify
* natural order.
*
* @param keyComparator the comparator that determines the key ordering
* @param valueComparator the comparator that determines the value ordering
*/
public static <K, V> TreeMultimap<K, V> create(
Comparator<? super K> keyComparator,
Comparator<? super V> valueComparator) {
return new TreeMultimap<K, V>(checkNotNull(keyComparator),
checkNotNull(valueComparator));
}
/**
* Constructs a {@code TreeMultimap}, ordered by the natural ordering of its
* keys and values, with the same mappings as the specified multimap.
*
* @param multimap the multimap whose contents are copied to this multimap
*/
public static <K extends Comparable, V extends Comparable>
TreeMultimap<K, V> create(Multimap<? extends K, ? extends V> multimap) {
return new TreeMultimap<K, V>(Ordering.natural(), Ordering.natural(),
multimap);
}
TreeMultimap(Comparator<? super K> keyComparator,
Comparator<? super V> valueComparator) {
super(new TreeMap<K, Collection<V>>(keyComparator));
this.keyComparator = keyComparator;
this.valueComparator = valueComparator;
}
private TreeMultimap(Comparator<? super K> keyComparator,
Comparator<? super V> valueComparator,
Multimap<? extends K, ? extends V> multimap) {
this(keyComparator, valueComparator);
putAll(multimap);
}
/**
* {@inheritDoc}
*
* <p>Creates an empty {@code TreeSet} for a collection of values for one key.
*
* @return a new {@code TreeSet} containing a collection of values for one
* key
*/
@Override SortedSet<V> createCollection() {
return new TreeSet<V>(valueComparator);
}
/**
* Returns the comparator that orders the multimap keys.
*/
public Comparator<? super K> keyComparator() {
return keyComparator;
}
@Override
public Comparator<? super V> valueComparator() {
return valueComparator;
}
/**
* {@inheritDoc}
*
* <p>Because a {@code TreeMultimap} has unique sorted keys, this method
* returns a {@link SortedSet}, instead of the {@link java.util.Set} specified
* in the {@link Multimap} interface.
*/
@Override public SortedSet<K> keySet() {
return (SortedSet<K>) super.keySet();
}
/**
* {@inheritDoc}
*
* <p>Because a {@code TreeMultimap} has unique sorted keys, this method
* returns a {@link SortedMap}, instead of the {@link java.util.Map} specified
* in the {@link Multimap} interface.
*/
@Override public SortedMap<K, Collection<V>> asMap() {
return (SortedMap<K, Collection<V>>) super.asMap();
}
}
| Java |
/*
* Copyright (C) 2007 The Guava Authors
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package com.google.common.collect;
import static com.google.common.base.Preconditions.checkArgument;
import static com.google.common.base.Preconditions.checkNotNull;
import static com.google.common.base.Preconditions.checkState;
import static com.google.common.collect.Multisets.setCountImpl;
import static java.util.Collections.unmodifiableList;
import com.google.common.annotations.GwtCompatible;
import com.google.common.base.Objects;
import com.google.common.base.Preconditions;
import java.io.Serializable;
import java.util.AbstractCollection;
import java.util.AbstractMap;
import java.util.AbstractSequentialList;
import java.util.AbstractSet;
import java.util.Collection;
import java.util.Iterator;
import java.util.List;
import java.util.ListIterator;
import java.util.Map;
import java.util.Map.Entry;
import java.util.NoSuchElementException;
import java.util.Set;
import javax.annotation.Nullable;
/**
* An implementation of {@code ListMultimap} that supports deterministic
* iteration order for both keys and values. The iteration order is preserved
* across non-distinct key values. For example, for the following multimap
* definition: <pre> {@code
*
* Multimap<K, V> multimap = LinkedListMultimap.create();
* multimap.put(key1, foo);
* multimap.put(key2, bar);
* multimap.put(key1, baz);}</pre>
*
* ... the iteration order for {@link #keys()} is {@code [key1, key2, key1]},
* and similarly for {@link #entries()}. Unlike {@link LinkedHashMultimap}, the
* iteration order is kept consistent between keys, entries and values. For
* example, calling: <pre> {@code
*
* map.remove(key1, foo);}</pre>
*
* changes the entries iteration order to {@code [key2=bar, key1=baz]} and the
* key iteration order to {@code [key2, key1]}. The {@link #entries()} iterator
* returns mutable map entries, and {@link #replaceValues} attempts to preserve
* iteration order as much as possible.
*
* <p>The collections returned by {@link #keySet()} and {@link #asMap} iterate
* through the keys in the order they were first added to the multimap.
* Similarly, {@link #get}, {@link #removeAll}, and {@link #replaceValues}
* return collections that iterate through the values in the order they were
* added. The collections generated by {@link #entries()}, {@link #keys()}, and
* {@link #values} iterate across the key-value mappings in the order they were
* added to the multimap.
*
* <p>The {@link #values()} and {@link #entries()} methods both return a
* {@code List}, instead of the {@code Collection} specified by the {@link
* ListMultimap} interface.
*
* <p>The methods {@link #get}, {@link #keySet()}, {@link #keys()},
* {@link #values}, {@link #entries()}, and {@link #asMap} return collections
* that are views of the multimap. If the multimap is modified while an
* iteration over any of those collections is in progress, except through the
* iterator's methods, the results of the iteration are undefined.
*
* <p>Keys and values may be null. All optional multimap methods are supported,
* and all returned views are modifiable.
*
* <p>This class is not threadsafe when any concurrent operations update the
* multimap. Concurrent read operations will work correctly. To allow concurrent
* update operations, wrap your multimap with a call to {@link
* Multimaps#synchronizedListMultimap}.
*
* <p>See the Guava User Guide article on <a href=
* "http://code.google.com/p/guava-libraries/wiki/NewCollectionTypesExplained#Multimap">
* {@code Multimap}</a>.
*
* @author Mike Bostock
* @since 2.0 (imported from Google Collections Library)
*/
@GwtCompatible(serializable = true, emulated = true)
public class LinkedListMultimap<K, V>
implements ListMultimap<K, V>, Serializable {
/*
* Order is maintained using a linked list containing all key-value pairs. In
* addition, a series of disjoint linked lists of "siblings", each containing
* the values for a specific key, is used to implement {@link
* ValueForKeyIterator} in constant time.
*/
private static final class Node<K, V> {
final K key;
V value;
Node<K, V> next; // the next node (with any key)
Node<K, V> previous; // the previous node (with any key)
Node<K, V> nextSibling; // the next node with the same key
Node<K, V> previousSibling; // the previous node with the same key
Node(@Nullable K key, @Nullable V value) {
this.key = key;
this.value = value;
}
@Override public String toString() {
return key + "=" + value;
}
}
private transient Node<K, V> head; // the head for all keys
private transient Node<K, V> tail; // the tail for all keys
private transient Multiset<K> keyCount; // the number of values for each key
private transient Map<K, Node<K, V>> keyToKeyHead; // the head for a given key
private transient Map<K, Node<K, V>> keyToKeyTail; // the tail for a given key
/**
* Creates a new, empty {@code LinkedListMultimap} with the default initial
* capacity.
*/
public static <K, V> LinkedListMultimap<K, V> create() {
return new LinkedListMultimap<K, V>();
}
/**
* Constructs an empty {@code LinkedListMultimap} with enough capacity to hold
* the specified number of keys without rehashing.
*
* @param expectedKeys the expected number of distinct keys
* @throws IllegalArgumentException if {@code expectedKeys} is negative
*/
public static <K, V> LinkedListMultimap<K, V> create(int expectedKeys) {
return new LinkedListMultimap<K, V>(expectedKeys);
}
/**
* Constructs a {@code LinkedListMultimap} with the same mappings as the
* specified {@code Multimap}. The new multimap has the same
* {@link Multimap#entries()} iteration order as the input multimap.
*
* @param multimap the multimap whose contents are copied to this multimap
*/
public static <K, V> LinkedListMultimap<K, V> create(
Multimap<? extends K, ? extends V> multimap) {
return new LinkedListMultimap<K, V>(multimap);
}
LinkedListMultimap() {
keyCount = LinkedHashMultiset.create();
keyToKeyHead = Maps.newHashMap();
keyToKeyTail = Maps.newHashMap();
}
private LinkedListMultimap(int expectedKeys) {
keyCount = LinkedHashMultiset.create(expectedKeys);
keyToKeyHead = Maps.newHashMapWithExpectedSize(expectedKeys);
keyToKeyTail = Maps.newHashMapWithExpectedSize(expectedKeys);
}
private LinkedListMultimap(Multimap<? extends K, ? extends V> multimap) {
this(multimap.keySet().size());
putAll(multimap);
}
/**
* Adds a new node for the specified key-value pair before the specified
* {@code nextSibling} element, or at the end of the list if {@code
* nextSibling} is null. Note: if {@code nextSibling} is specified, it MUST be
* for an node for the same {@code key}!
*/
private Node<K, V> addNode(
@Nullable K key, @Nullable V value, @Nullable Node<K, V> nextSibling) {
Node<K, V> node = new Node<K, V>(key, value);
if (head == null) { // empty list
head = tail = node;
keyToKeyHead.put(key, node);
keyToKeyTail.put(key, node);
} else if (nextSibling == null) { // non-empty list, add to tail
tail.next = node;
node.previous = tail;
Node<K, V> keyTail = keyToKeyTail.get(key);
if (keyTail == null) { // first for this key
keyToKeyHead.put(key, node);
} else {
keyTail.nextSibling = node;
node.previousSibling = keyTail;
}
keyToKeyTail.put(key, node);
tail = node;
} else { // non-empty list, insert before nextSibling
node.previous = nextSibling.previous;
node.previousSibling = nextSibling.previousSibling;
node.next = nextSibling;
node.nextSibling = nextSibling;
if (nextSibling.previousSibling == null) { // nextSibling was key head
keyToKeyHead.put(key, node);
} else {
nextSibling.previousSibling.nextSibling = node;
}
if (nextSibling.previous == null) { // nextSibling was head
head = node;
} else {
nextSibling.previous.next = node;
}
nextSibling.previous = node;
nextSibling.previousSibling = node;
}
keyCount.add(key);
return node;
}
/**
* Removes the specified node from the linked list. This method is only
* intended to be used from the {@code Iterator} classes. See also {@link
* LinkedListMultimap#removeAllNodes(Object)}.
*/
private void removeNode(Node<K, V> node) {
if (node.previous != null) {
node.previous.next = node.next;
} else { // node was head
head = node.next;
}
if (node.next != null) {
node.next.previous = node.previous;
} else { // node was tail
tail = node.previous;
}
if (node.previousSibling != null) {
node.previousSibling.nextSibling = node.nextSibling;
} else if (node.nextSibling != null) { // node was key head
keyToKeyHead.put(node.key, node.nextSibling);
} else {
keyToKeyHead.remove(node.key); // don't leak a key-null entry
}
if (node.nextSibling != null) {
node.nextSibling.previousSibling = node.previousSibling;
} else if (node.previousSibling != null) { // node was key tail
keyToKeyTail.put(node.key, node.previousSibling);
} else {
keyToKeyTail.remove(node.key); // don't leak a key-null entry
}
keyCount.remove(node.key);
}
/** Removes all nodes for the specified key. */
private void removeAllNodes(@Nullable Object key) {
for (Iterator<V> i = new ValueForKeyIterator(key); i.hasNext();) {
i.next();
i.remove();
}
}
/** Helper method for verifying that an iterator element is present. */
private static void checkElement(@Nullable Object node) {
if (node == null) {
throw new NoSuchElementException();
}
}
/** An {@code Iterator} over all nodes. */
private class NodeIterator implements ListIterator<Node<K, V>> {
int nextIndex;
Node<K, V> next;
Node<K, V> current;
Node<K, V> previous;
NodeIterator() {
next = head;
}
NodeIterator(int index) {
int size = size();
Preconditions.checkPositionIndex(index, size);
if (index >= (size / 2)) {
previous = tail;
nextIndex = size;
while (index++ < size) {
previous();
}
} else {
next = head;
while (index-- > 0) {
next();
}
}
current = null;
}
@Override
public boolean hasNext() {
return next != null;
}
@Override
public Node<K, V> next() {
checkElement(next);
previous = current = next;
next = next.next;
nextIndex++;
return current;
}
@Override
public void remove() {
checkState(current != null);
if (current != next) { // after call to next()
previous = current.previous;
nextIndex--;
} else { // after call to previous()
next = current.next;
}
removeNode(current);
current = null;
}
@Override
public boolean hasPrevious() {
return previous != null;
}
@Override
public Node<K, V> previous() {
checkElement(previous);
next = current = previous;
previous = previous.previous;
nextIndex--;
return current;
}
@Override
public int nextIndex() {
return nextIndex;
}
@Override
public int previousIndex() {
return nextIndex - 1;
}
@Override
public void set(Node<K, V> e) {
throw new UnsupportedOperationException();
}
@Override
public void add(Node<K, V> e) {
throw new UnsupportedOperationException();
}
void setValue(V value) {
checkState(current != null);
current.value = value;
}
}
/** An {@code Iterator} over distinct keys in key head order. */
private class DistinctKeyIterator implements Iterator<K> {
final Set<K> seenKeys = Sets.<K>newHashSetWithExpectedSize(keySet().size());
Node<K, V> next = head;
Node<K, V> current;
@Override
public boolean hasNext() {
return next != null;
}
@Override
public K next() {
checkElement(next);
current = next;
seenKeys.add(current.key);
do { // skip ahead to next unseen key
next = next.next;
} while ((next != null) && !seenKeys.add(next.key));
return current.key;
}
@Override
public void remove() {
checkState(current != null);
removeAllNodes(current.key);
current = null;
}
}
/** A {@code ListIterator} over values for a specified key. */
private class ValueForKeyIterator implements ListIterator<V> {
final Object key;
int nextIndex;
Node<K, V> next;
Node<K, V> current;
Node<K, V> previous;
/** Constructs a new iterator over all values for the specified key. */
ValueForKeyIterator(@Nullable Object key) {
this.key = key;
next = keyToKeyHead.get(key);
}
/**
* Constructs a new iterator over all values for the specified key starting
* at the specified index. This constructor is optimized so that it starts
* at either the head or the tail, depending on which is closer to the
* specified index. This allows adds to the tail to be done in constant
* time.
*
* @throws IndexOutOfBoundsException if index is invalid
*/
public ValueForKeyIterator(@Nullable Object key, int index) {
int size = keyCount.count(key);
Preconditions.checkPositionIndex(index, size);
if (index >= (size / 2)) {
previous = keyToKeyTail.get(key);
nextIndex = size;
while (index++ < size) {
previous();
}
} else {
next = keyToKeyHead.get(key);
while (index-- > 0) {
next();
}
}
this.key = key;
current = null;
}
@Override
public boolean hasNext() {
return next != null;
}
@Override
public V next() {
checkElement(next);
previous = current = next;
next = next.nextSibling;
nextIndex++;
return current.value;
}
@Override
public boolean hasPrevious() {
return previous != null;
}
@Override
public V previous() {
checkElement(previous);
next = current = previous;
previous = previous.previousSibling;
nextIndex--;
return current.value;
}
@Override
public int nextIndex() {
return nextIndex;
}
@Override
public int previousIndex() {
return nextIndex - 1;
}
@Override
public void remove() {
checkState(current != null);
if (current != next) { // after call to next()
previous = current.previousSibling;
nextIndex--;
} else { // after call to previous()
next = current.nextSibling;
}
removeNode(current);
current = null;
}
@Override
public void set(V value) {
checkState(current != null);
current.value = value;
}
@Override
@SuppressWarnings("unchecked")
public void add(V value) {
previous = addNode((K) key, value, next);
nextIndex++;
current = null;
}
}
// Query Operations
@Override
public int size() {
return keyCount.size();
}
@Override
public boolean isEmpty() {
return head == null;
}
@Override
public boolean containsKey(@Nullable Object key) {
return keyToKeyHead.containsKey(key);
}
@Override
public boolean containsValue(@Nullable Object value) {
for (Iterator<Node<K, V>> i = new NodeIterator(); i.hasNext();) {
if (Objects.equal(i.next().value, value)) {
return true;
}
}
return false;
}
@Override
public boolean containsEntry(@Nullable Object key, @Nullable Object value) {
for (Iterator<V> i = new ValueForKeyIterator(key); i.hasNext();) {
if (Objects.equal(i.next(), value)) {
return true;
}
}
return false;
}
// Modification Operations
/**
* Stores a key-value pair in the multimap.
*
* @param key key to store in the multimap
* @param value value to store in the multimap
* @return {@code true} always
*/
@Override
public boolean put(@Nullable K key, @Nullable V value) {
addNode(key, value, null);
return true;
}
@Override
public boolean remove(@Nullable Object key, @Nullable Object value) {
Iterator<V> values = new ValueForKeyIterator(key);
while (values.hasNext()) {
if (Objects.equal(values.next(), value)) {
values.remove();
return true;
}
}
return false;
}
// Bulk Operations
@Override
public boolean putAll(@Nullable K key, Iterable<? extends V> values) {
boolean changed = false;
for (V value : values) {
changed |= put(key, value);
}
return changed;
}
@Override
public boolean putAll(Multimap<? extends K, ? extends V> multimap) {
boolean changed = false;
for (Entry<? extends K, ? extends V> entry : multimap.entries()) {
changed |= put(entry.getKey(), entry.getValue());
}
return changed;
}
/**
* {@inheritDoc}
*
* <p>If any entries for the specified {@code key} already exist in the
* multimap, their values are changed in-place without affecting the iteration
* order.
*
* <p>The returned list is immutable and implements
* {@link java.util.RandomAccess}.
*/
@Override
public List<V> replaceValues(@Nullable K key, Iterable<? extends V> values) {
List<V> oldValues = getCopy(key);
ListIterator<V> keyValues = new ValueForKeyIterator(key);
Iterator<? extends V> newValues = values.iterator();
// Replace existing values, if any.
while (keyValues.hasNext() && newValues.hasNext()) {
keyValues.next();
keyValues.set(newValues.next());
}
// Remove remaining old values, if any.
while (keyValues.hasNext()) {
keyValues.next();
keyValues.remove();
}
// Add remaining new values, if any.
while (newValues.hasNext()) {
keyValues.add(newValues.next());
}
return oldValues;
}
private List<V> getCopy(@Nullable Object key) {
return unmodifiableList(Lists.newArrayList(new ValueForKeyIterator(key)));
}
/**
* {@inheritDoc}
*
* <p>The returned list is immutable and implements
* {@link java.util.RandomAccess}.
*/
@Override
public List<V> removeAll(@Nullable Object key) {
List<V> oldValues = getCopy(key);
removeAllNodes(key);
return oldValues;
}
@Override
public void clear() {
head = null;
tail = null;
keyCount.clear();
keyToKeyHead.clear();
keyToKeyTail.clear();
}
// Views
/**
* {@inheritDoc}
*
* <p>If the multimap is modified while an iteration over the list is in
* progress (except through the iterator's own {@code add}, {@code set} or
* {@code remove} operations) the results of the iteration are undefined.
*
* <p>The returned list is not serializable and does not have random access.
*/
@Override
public List<V> get(final @Nullable K key) {
return new AbstractSequentialList<V>() {
@Override public int size() {
return keyCount.count(key);
}
@Override public ListIterator<V> listIterator(int index) {
return new ValueForKeyIterator(key, index);
}
@Override public boolean removeAll(Collection<?> c) {
return Iterators.removeAll(iterator(), c);
}
@Override public boolean retainAll(Collection<?> c) {
return Iterators.retainAll(iterator(), c);
}
};
}
private transient Set<K> keySet;
@Override
public Set<K> keySet() {
Set<K> result = keySet;
if (result == null) {
keySet = result = new AbstractSet<K>() {
@Override public int size() {
return keyCount.elementSet().size();
}
@Override public Iterator<K> iterator() {
return new DistinctKeyIterator();
}
@Override public boolean contains(Object key) { // for performance
return keyCount.contains(key);
}
@Override public boolean removeAll(Collection<?> c) {
checkNotNull(c); // eager for GWT
return super.removeAll(c);
}
};
}
return result;
}
private transient Multiset<K> keys;
@Override
public Multiset<K> keys() {
Multiset<K> result = keys;
if (result == null) {
keys = result = new MultisetView();
}
return result;
}
private class MultisetView extends AbstractCollection<K>
implements Multiset<K> {
@Override public int size() {
return keyCount.size();
}
@Override public Iterator<K> iterator() {
final Iterator<Node<K, V>> nodes = new NodeIterator();
return new Iterator<K>() {
@Override
public boolean hasNext() {
return nodes.hasNext();
}
@Override
public K next() {
return nodes.next().key;
}
@Override
public void remove() {
nodes.remove();
}
};
}
@Override
public int count(@Nullable Object key) {
return keyCount.count(key);
}
@Override
public int add(@Nullable K key, int occurrences) {
throw new UnsupportedOperationException();
}
@Override
public int remove(@Nullable Object key, int occurrences) {
checkArgument(occurrences >= 0);
int oldCount = count(key);
Iterator<V> values = new ValueForKeyIterator(key);
while ((occurrences-- > 0) && values.hasNext()) {
values.next();
values.remove();
}
return oldCount;
}
@Override
public int setCount(K element, int count) {
return setCountImpl(this, element, count);
}
@Override
public boolean setCount(K element, int oldCount, int newCount) {
return setCountImpl(this, element, oldCount, newCount);
}
@Override public boolean removeAll(Collection<?> c) {
return Iterators.removeAll(iterator(), c);
}
@Override public boolean retainAll(Collection<?> c) {
return Iterators.retainAll(iterator(), c);
}
@Override
public Set<K> elementSet() {
return keySet();
}
@Override
public Set<Entry<K>> entrySet() {
// TODO(jlevy): lazy init?
return new AbstractSet<Entry<K>>() {
@Override public int size() {
return keyCount.elementSet().size();
}
@Override public Iterator<Entry<K>> iterator() {
final Iterator<K> keyIterator = new DistinctKeyIterator();
return new Iterator<Entry<K>>() {
@Override
public boolean hasNext() {
return keyIterator.hasNext();
}
@Override
public Entry<K> next() {
final K key = keyIterator.next();
return new Multisets.AbstractEntry<K>() {
@Override
public K getElement() {
return key;
}
@Override
public int getCount() {
return keyCount.count(key);
}
};
}
@Override
public void remove() {
keyIterator.remove();
}
};
}
};
}
@Override public boolean equals(@Nullable Object object) {
return keyCount.equals(object);
}
@Override public int hashCode() {
return keyCount.hashCode();
}
@Override public String toString() {
return keyCount.toString(); // XXX observe order?
}
}
private transient List<V> valuesList;
/**
* {@inheritDoc}
*
* <p>The iterator generated by the returned collection traverses the values
* in the order they were added to the multimap. Because the values may have
* duplicates and follow the insertion ordering, this method returns a {@link
* List}, instead of the {@link Collection} specified in the {@link
* ListMultimap} interface.
*/
@Override
public List<V> values() {
List<V> result = valuesList;
if (result == null) {
valuesList = result = new AbstractSequentialList<V>() {
@Override public int size() {
return keyCount.size();
}
@Override
public ListIterator<V> listIterator(int index) {
final NodeIterator nodes = new NodeIterator(index);
return new ListIterator<V>() {
@Override
public boolean hasNext() {
return nodes.hasNext();
}
@Override
public V next() {
return nodes.next().value;
}
@Override
public boolean hasPrevious() {
return nodes.hasPrevious();
}
@Override
public V previous() {
return nodes.previous().value;
}
@Override
public int nextIndex() {
return nodes.nextIndex();
}
@Override
public int previousIndex() {
return nodes.previousIndex();
}
@Override
public void remove() {
nodes.remove();
}
@Override
public void set(V e) {
nodes.setValue(e);
}
@Override
public void add(V e) {
throw new UnsupportedOperationException();
}
};
}
};
}
return result;
}
private static <K, V> Entry<K, V> createEntry(final Node<K, V> node) {
return new AbstractMapEntry<K, V>() {
@Override public K getKey() {
return node.key;
}
@Override public V getValue() {
return node.value;
}
@Override public V setValue(V value) {
V oldValue = node.value;
node.value = value;
return oldValue;
}
};
}
private transient List<Entry<K, V>> entries;
/**
* {@inheritDoc}
*
* <p>The iterator generated by the returned collection traverses the entries
* in the order they were added to the multimap. Because the entries may have
* duplicates and follow the insertion ordering, this method returns a {@link
* List}, instead of the {@link Collection} specified in the {@link
* ListMultimap} interface.
*
* <p>An entry's {@link Entry#getKey} method always returns the same key,
* regardless of what happens subsequently. As long as the corresponding
* key-value mapping is not removed from the multimap, {@link Entry#getValue}
* returns the value from the multimap, which may change over time, and {@link
* Entry#setValue} modifies that value. Removing the mapping from the
* multimap does not alter the value returned by {@code getValue()}, though a
* subsequent {@code setValue()} call won't update the multimap but will lead
* to a revised value being returned by {@code getValue()}.
*/
@Override
public List<Entry<K, V>> entries() {
List<Entry<K, V>> result = entries;
if (result == null) {
entries = result = new AbstractSequentialList<Entry<K, V>>() {
@Override public int size() {
return keyCount.size();
}
@Override public ListIterator<Entry<K, V>> listIterator(int index) {
final ListIterator<Node<K, V>> nodes = new NodeIterator(index);
return new ListIterator<Entry<K, V>>() {
@Override
public boolean hasNext() {
return nodes.hasNext();
}
@Override
public Entry<K, V> next() {
return createEntry(nodes.next());
}
@Override
public void remove() {
nodes.remove();
}
@Override
public boolean hasPrevious() {
return nodes.hasPrevious();
}
@Override
public Map.Entry<K, V> previous() {
return createEntry(nodes.previous());
}
@Override
public int nextIndex() {
return nodes.nextIndex();
}
@Override
public int previousIndex() {
return nodes.previousIndex();
}
@Override
public void set(Map.Entry<K, V> e) {
throw new UnsupportedOperationException();
}
@Override
public void add(Map.Entry<K, V> e) {
throw new UnsupportedOperationException();
}
};
}
};
}
return result;
}
private class AsMapEntries extends AbstractSet<Entry<K, Collection<V>>> {
@Override public int size() {
return keyCount.elementSet().size();
}
@Override public Iterator<Entry<K, Collection<V>>> iterator() {
final Iterator<K> keyIterator = new DistinctKeyIterator();
return new Iterator<Entry<K, Collection<V>>>() {
@Override
public boolean hasNext() {
return keyIterator.hasNext();
}
@Override
public Entry<K, Collection<V>> next() {
final K key = keyIterator.next();
return new AbstractMapEntry<K, Collection<V>>() {
@Override public K getKey() {
return key;
}
@Override public Collection<V> getValue() {
return LinkedListMultimap.this.get(key);
}
};
}
@Override
public void remove() {
keyIterator.remove();
}
};
}
// TODO(jlevy): Override contains() and remove() for better performance.
}
private transient Map<K, Collection<V>> map;
@Override
public Map<K, Collection<V>> asMap() {
Map<K, Collection<V>> result = map;
if (result == null) {
map = result = new AbstractMap<K, Collection<V>>() {
Set<Entry<K, Collection<V>>> entrySet;
@Override public Set<Entry<K, Collection<V>>> entrySet() {
Set<Entry<K, Collection<V>>> result = entrySet;
if (result == null) {
entrySet = result = new AsMapEntries();
}
return result;
}
// The following methods are included for performance.
@Override public boolean containsKey(@Nullable Object key) {
return LinkedListMultimap.this.containsKey(key);
}
@SuppressWarnings("unchecked")
@Override public Collection<V> get(@Nullable Object key) {
Collection<V> collection = LinkedListMultimap.this.get((K) key);
return collection.isEmpty() ? null : collection;
}
@Override public Collection<V> remove(@Nullable Object key) {
Collection<V> collection = removeAll(key);
return collection.isEmpty() ? null : collection;
}
};
}
return result;
}
// Comparison and hashing
/**
* Compares the specified object to this multimap for equality.
*
* <p>Two {@code ListMultimap} instances are equal if, for each key, they
* contain the same values in the same order. If the value orderings disagree,
* the multimaps will not be considered equal.
*/
@Override public boolean equals(@Nullable Object other) {
if (other == this) {
return true;
}
if (other instanceof Multimap) {
Multimap<?, ?> that = (Multimap<?, ?>) other;
return this.asMap().equals(that.asMap());
}
return false;
}
/**
* Returns the hash code for this multimap.
*
* <p>The hash code of a multimap is defined as the hash code of the map view,
* as returned by {@link Multimap#asMap}.
*/
@Override public int hashCode() {
return asMap().hashCode();
}
/**
* Returns a string representation of the multimap, generated by calling
* {@code toString} on the map returned by {@link Multimap#asMap}.
*
* @return a string representation of the multimap
*/
@Override public String toString() {
return asMap().toString();
}
}
| Java |
/*
* Copyright (C) 2009 The Guava Authors
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package com.google.common.collect;
/**
* GWT emulated version of EmptyImmutableList.
*
* @author Hayward Chan
*/
final class EmptyImmutableList extends ImmutableList<Object> {
static final EmptyImmutableList INSTANCE = new EmptyImmutableList();
}
| Java |
/*
* Copyright (C) 2007 The Guava Authors
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package com.google.common.collect;
import com.google.common.annotations.GwtCompatible;
import java.util.HashMap;
/**
* Multiset implementation backed by a {@link HashMap}.
*
* @author Kevin Bourrillion
* @author Jared Levy
* @since 2.0 (imported from Google Collections Library)
*/
@GwtCompatible(serializable = true, emulated = true)
public final class HashMultiset<E> extends AbstractMapBasedMultiset<E> {
/**
* Creates a new, empty {@code HashMultiset} using the default initial
* capacity.
*/
public static <E> HashMultiset<E> create() {
return new HashMultiset<E>();
}
/**
* Creates a new, empty {@code HashMultiset} with the specified expected
* number of distinct elements.
*
* @param distinctElements the expected number of distinct elements
* @throws IllegalArgumentException if {@code distinctElements} is negative
*/
public static <E> HashMultiset<E> create(int distinctElements) {
return new HashMultiset<E>(distinctElements);
}
/**
* Creates a new {@code HashMultiset} containing the specified elements.
*
* <p>This implementation is highly efficient when {@code elements} is itself
* a {@link Multiset}.
*
* @param elements the elements that the multiset should contain
*/
public static <E> HashMultiset<E> create(Iterable<? extends E> elements) {
HashMultiset<E> multiset =
create(Multisets.inferDistinctElements(elements));
Iterables.addAll(multiset, elements);
return multiset;
}
private HashMultiset() {
super(new HashMap<E, Count>());
}
private HashMultiset(int distinctElements) {
super(Maps.<E, Count>newHashMapWithExpectedSize(distinctElements));
}
}
| Java |
/*
* Copyright (C) 2007 The Guava Authors
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package com.google.common.collect;
import static com.google.common.base.Preconditions.checkArgument;
import static com.google.common.base.Preconditions.checkNotNull;
import com.google.common.annotations.GwtCompatible;
import java.util.EnumMap;
import java.util.Map;
/**
* A {@code BiMap} backed by two {@code EnumMap} instances. Null keys and values
* are not permitted. An {@code EnumBiMap} and its inverse are both
* serializable.
*
* <p>See the Guava User Guide article on <a href=
* "http://code.google.com/p/guava-libraries/wiki/NewCollectionTypesExplained#BiMap">
* {@code BiMap}</a>.
*
* @author Mike Bostock
* @since 2.0 (imported from Google Collections Library)
*/
@GwtCompatible(emulated = true)
public final class EnumBiMap<K extends Enum<K>, V extends Enum<V>>
extends AbstractBiMap<K, V> {
private transient Class<K> keyType;
private transient Class<V> valueType;
/**
* Returns a new, empty {@code EnumBiMap} using the specified key and value
* types.
*
* @param keyType the key type
* @param valueType the value type
*/
public static <K extends Enum<K>, V extends Enum<V>> EnumBiMap<K, V>
create(Class<K> keyType, Class<V> valueType) {
return new EnumBiMap<K, V>(keyType, valueType);
}
/**
* Returns a new bimap with the same mappings as the specified map. If the
* specified map is an {@code EnumBiMap}, the new bimap has the same types as
* the provided map. Otherwise, the specified map must contain at least one
* mapping, in order to determine the key and value types.
*
* @param map the map whose mappings are to be placed in this map
* @throws IllegalArgumentException if map is not an {@code EnumBiMap}
* instance and contains no mappings
*/
public static <K extends Enum<K>, V extends Enum<V>> EnumBiMap<K, V>
create(Map<K, V> map) {
EnumBiMap<K, V> bimap = create(inferKeyType(map), inferValueType(map));
bimap.putAll(map);
return bimap;
}
private EnumBiMap(Class<K> keyType, Class<V> valueType) {
super(WellBehavedMap.wrap(new EnumMap<K, V>(keyType)),
WellBehavedMap.wrap(new EnumMap<V, K>(valueType)));
this.keyType = keyType;
this.valueType = valueType;
}
static <K extends Enum<K>> Class<K> inferKeyType(Map<K, ?> map) {
if (map instanceof EnumBiMap) {
return ((EnumBiMap<K, ?>) map).keyType();
}
if (map instanceof EnumHashBiMap) {
return ((EnumHashBiMap<K, ?>) map).keyType();
}
checkArgument(!map.isEmpty());
return map.keySet().iterator().next().getDeclaringClass();
}
private static <V extends Enum<V>> Class<V> inferValueType(Map<?, V> map) {
if (map instanceof EnumBiMap) {
return ((EnumBiMap<?, V>) map).valueType;
}
checkArgument(!map.isEmpty());
return map.values().iterator().next().getDeclaringClass();
}
/** Returns the associated key type. */
public Class<K> keyType() {
return keyType;
}
/** Returns the associated value type. */
public Class<V> valueType() {
return valueType;
}
@Override
K checkKey(K key) {
return checkNotNull(key);
}
@Override
V checkValue(V value) {
return checkNotNull(value);
}
}
| Java |
/*
* Copyright (C) 2009 The Guava Authors
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package com.google.common.collect;
import java.util.List;
/**
* GWT emulated version of {@link RegularImmutableList}.
*
* @author Hayward Chan
*/
class RegularImmutableList<E> extends ImmutableList<E> {
RegularImmutableList(List<E> delegate) {
super(delegate);
}
}
| Java |
/*
* Copyright (C) 2009 The Guava Authors
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package com.google.common.collect;
import static com.google.common.base.Preconditions.checkNotNull;
import static com.google.common.base.Preconditions.checkArgument;
import java.util.ArrayList;
import java.util.Collection;
import java.util.Collections;
import java.util.Comparator;
import java.util.Iterator;
import java.util.List;
import java.util.SortedSet;
import java.util.TreeSet;
import javax.annotation.Nullable;
/**
* GWT emulation of {@link ImmutableSortedSet}.
*
* @author Hayward Chan
*/
public abstract class ImmutableSortedSet<E>
extends ImmutableSet<E> implements SortedSet<E>, SortedIterable<E> {
// In the non-emulated source, this is in ImmutableSortedSetFauxverideShim,
// which overrides ImmutableSet & which ImmutableSortedSet extends.
// It is necessary here because otherwise the builder() method
// would be inherited from the emulated ImmutableSet.
@Deprecated public static <E> ImmutableSortedSet.Builder<E> builder() {
throw new UnsupportedOperationException();
}
// TODO: Can we find a way to remove this @SuppressWarnings even for eclipse?
@SuppressWarnings("unchecked")
private static final Comparator NATURAL_ORDER = Ordering.natural();
@SuppressWarnings("unchecked")
private static final ImmutableSortedSet<Object> NATURAL_EMPTY_SET =
new EmptyImmutableSortedSet<Object>(NATURAL_ORDER);
@SuppressWarnings("unchecked")
private static <E> ImmutableSortedSet<E> emptySet() {
return (ImmutableSortedSet<E>) NATURAL_EMPTY_SET;
}
static <E> ImmutableSortedSet<E> emptySet(
Comparator<? super E> comparator) {
checkNotNull(comparator);
if (NATURAL_ORDER.equals(comparator)) {
return emptySet();
} else {
return new EmptyImmutableSortedSet<E>(comparator);
}
}
public static <E> ImmutableSortedSet<E> of() {
return emptySet();
}
public static <E extends Comparable<? super E>> ImmutableSortedSet<E> of(
E element) {
return ofInternal(Ordering.natural(), element);
}
@SuppressWarnings("unchecked")
public static <E extends Comparable<? super E>> ImmutableSortedSet<E> of(
E e1, E e2) {
return ofInternal(Ordering.natural(), e1, e2);
}
@SuppressWarnings("unchecked")
public static <E extends Comparable<? super E>> ImmutableSortedSet<E> of(
E e1, E e2, E e3) {
return ofInternal(Ordering.natural(), e1, e2, e3);
}
@SuppressWarnings("unchecked")
public static <E extends Comparable<? super E>> ImmutableSortedSet<E> of(
E e1, E e2, E e3, E e4) {
return ofInternal(Ordering.natural(), e1, e2, e3, e4);
}
@SuppressWarnings("unchecked")
public static <E extends Comparable<? super E>> ImmutableSortedSet<E> of(
E e1, E e2, E e3, E e4, E e5) {
return ofInternal(Ordering.natural(), e1, e2, e3, e4, e5);
}
@SuppressWarnings("unchecked")
public static <E extends Comparable<? super E>> ImmutableSortedSet<E> of(
E e1, E e2, E e3, E e4, E e5, E e6, E... remaining) {
int size = remaining.length + 6;
List<E> all = new ArrayList<E>(size);
Collections.addAll(all, e1, e2, e3, e4, e5, e6);
Collections.addAll(all, remaining);
// This is messed up. See TODO at top of file.
return ofInternal(Ordering.natural(), (E[]) all.toArray(new Comparable[0]));
}
@Deprecated
public
static <E extends Comparable<? super E>> ImmutableSortedSet<E> of(
E[] elements) {
return copyOf(elements);
}
private static <E> ImmutableSortedSet<E> ofInternal(
Comparator<? super E> comparator, E... elements) {
checkNotNull(elements);
switch (elements.length) {
case 0:
return emptySet(comparator);
default:
SortedSet<E> delegate = new TreeSet<E>(comparator);
for (E element : elements) {
checkNotNull(element);
delegate.add(element);
}
return new RegularImmutableSortedSet<E>(delegate, false);
}
}
public static <E extends Comparable<? super E>> ImmutableSortedSet<E> copyOf(
Collection<? extends E> elements) {
return copyOfInternal(Ordering.natural(), elements, false);
}
public static <E extends Comparable<? super E>> ImmutableSortedSet<E> copyOf(
Iterable<? extends E> elements) {
return copyOfInternal(Ordering.natural(), elements, false);
}
public static <E extends Comparable<? super E>> ImmutableSortedSet<E> copyOf(
Iterator<? extends E> elements) {
return copyOfInternal(Ordering.natural(), elements);
}
public static <E extends Comparable<? super E>> ImmutableSortedSet<E> copyOf(
E[] elements) {
return ofInternal(Ordering.natural(), elements);
}
public static <E> ImmutableSortedSet<E> copyOf(
Comparator<? super E> comparator, Iterable<? extends E> elements) {
checkNotNull(comparator);
return copyOfInternal(comparator, elements, false);
}
public static <E> ImmutableSortedSet<E> copyOf(
Comparator<? super E> comparator, Collection<? extends E> elements) {
checkNotNull(comparator);
return copyOfInternal(comparator, elements, false);
}
public static <E> ImmutableSortedSet<E> copyOf(
Comparator<? super E> comparator, Iterator<? extends E> elements) {
checkNotNull(comparator);
return copyOfInternal(comparator, elements);
}
@SuppressWarnings("unchecked")
public static <E> ImmutableSortedSet<E> copyOfSorted(SortedSet<E> sortedSet) {
Comparator<? super E> comparator = sortedSet.comparator();
if (comparator == null) {
comparator = NATURAL_ORDER;
}
return copyOfInternal(comparator, sortedSet.iterator());
}
private static <E> ImmutableSortedSet<E> copyOfInternal(
Comparator<? super E> comparator, Iterable<? extends E> elements,
boolean fromSortedSet) {
checkNotNull(comparator);
boolean hasSameComparator
= fromSortedSet || hasSameComparator(elements, comparator);
if (hasSameComparator && (elements instanceof ImmutableSortedSet)) {
@SuppressWarnings("unchecked")
ImmutableSortedSet<E> result = (ImmutableSortedSet<E>) elements;
boolean isSubset = (result instanceof RegularImmutableSortedSet)
&& ((RegularImmutableSortedSet) result).isSubset;
if (!isSubset) {
// Only return the original copy if this immutable sorted set isn't
// a subset of another, to avoid memory leak.
return result;
}
}
return copyOfInternal(comparator, elements.iterator());
}
private static <E> ImmutableSortedSet<E> copyOfInternal(
Comparator<? super E> comparator, Iterator<? extends E> elements) {
checkNotNull(comparator);
if (!elements.hasNext()) {
return emptySet(comparator);
}
SortedSet<E> delegate = new TreeSet<E>(comparator);
while (elements.hasNext()) {
E element = elements.next();
checkNotNull(element);
delegate.add(element);
}
return new RegularImmutableSortedSet<E>(delegate, false);
}
private static boolean hasSameComparator(
Iterable<?> elements, Comparator<?> comparator) {
if (elements instanceof SortedSet) {
SortedSet<?> sortedSet = (SortedSet<?>) elements;
Comparator<?> comparator2 = sortedSet.comparator();
return (comparator2 == null)
? comparator == Ordering.natural()
: comparator.equals(comparator2);
}
return false;
}
// Assumes that delegate doesn't have null elements and comparator.
static <E> ImmutableSortedSet<E> unsafeDelegateSortedSet(
SortedSet<E> delegate, boolean isSubset) {
return delegate.isEmpty()
? emptySet(delegate.comparator())
: new RegularImmutableSortedSet<E>(delegate, isSubset);
}
// This reference is only used by GWT compiler to infer the elements of the
// set that needs to be serialized.
private Comparator<E> unusedComparatorForSerialization;
private E unusedElementForSerialization;
private transient final SortedSet<E> sortedDelegate;
ImmutableSortedSet(Comparator<? super E> comparator) {
this(Sets.newTreeSet(comparator));
}
ImmutableSortedSet(SortedSet<E> sortedDelegate) {
super(sortedDelegate);
this.sortedDelegate = Collections.unmodifiableSortedSet(sortedDelegate);
}
public Comparator<? super E> comparator() {
return sortedDelegate.comparator();
}
@Override // needed to unify SortedIterable and Collection iterator() methods
public UnmodifiableIterator<E> iterator() {
return super.iterator();
}
@Override public boolean contains(@Nullable Object object) {
try {
// This set never contains null. We need to explicitly check here
// because some comparator might throw NPE (e.g. the natural ordering).
return object != null && sortedDelegate.contains(object);
} catch (ClassCastException e) {
return false;
}
}
@Override public boolean containsAll(Collection<?> targets) {
for (Object target : targets) {
if (target == null) {
// This set never contains null. We need to explicitly check here
// because some comparator might throw NPE (e.g. the natural ordering).
return false;
}
}
try {
return sortedDelegate.containsAll(targets);
} catch (ClassCastException e) {
return false;
}
}
public E first() {
return sortedDelegate.first();
}
public ImmutableSortedSet<E> headSet(E toElement) {
checkNotNull(toElement);
try {
return unsafeDelegateSortedSet(sortedDelegate.headSet(toElement), true);
} catch (IllegalArgumentException e) {
return emptySet(comparator());
}
}
E higher(E e) {
checkNotNull(e);
Iterator<E> iterator = tailSet(e).iterator();
while (iterator.hasNext()) {
E higher = iterator.next();
if (comparator().compare(e, higher) < 0) {
return higher;
}
}
return null;
}
ImmutableSortedSet<E> headSet(E toElement, boolean inclusive) {
checkNotNull(toElement);
if (inclusive) {
E tmp = higher(toElement);
if (tmp == null) {
return this;
}
toElement = tmp;
}
return headSet(toElement);
}
public E last() {
return sortedDelegate.last();
}
public ImmutableSortedSet<E> subSet(E fromElement, E toElement) {
return subSet(fromElement, true, toElement, false);
}
ImmutableSortedSet<E> subSet(E fromElement, boolean fromInclusive, E toElement,
boolean toInclusive) {
checkNotNull(fromElement);
checkNotNull(toElement);
int cmp = comparator().compare(fromElement, toElement);
checkArgument(cmp <= 0, "fromElement (%s) is less than toElement (%s)", fromElement, toElement);
if (cmp == 0 && !(fromInclusive && toInclusive)) {
return emptySet(comparator());
}
return tailSet(fromElement, fromInclusive).headSet(toElement, toInclusive);
}
public ImmutableSortedSet<E> tailSet(E fromElement) {
checkNotNull(fromElement);
try {
return unsafeDelegateSortedSet(sortedDelegate.tailSet(fromElement), true);
} catch (IllegalArgumentException e) {
return emptySet(comparator());
}
}
ImmutableSortedSet<E> tailSet(E fromElement, boolean inclusive) {
checkNotNull(fromElement);
if (!inclusive) {
E tmp = higher(fromElement);
if (tmp == null) {
return emptySet(comparator());
}
fromElement = tmp;
}
return tailSet(fromElement);
}
public static <E> Builder<E> orderedBy(Comparator<E> comparator) {
return new Builder<E>(comparator);
}
public static <E extends Comparable<E>> Builder<E> reverseOrder() {
return new Builder<E>(Ordering.natural().reverse());
}
public static <E extends Comparable<E>> Builder<E> naturalOrder() {
return new Builder<E>(Ordering.natural());
}
public static final class Builder<E> extends ImmutableSet.Builder<E> {
private final Comparator<? super E> comparator;
public Builder(Comparator<? super E> comparator) {
this.comparator = checkNotNull(comparator);
}
@Override public Builder<E> add(E element) {
super.add(element);
return this;
}
@Override public Builder<E> add(E... elements) {
super.add(elements);
return this;
}
@Override public Builder<E> addAll(Iterable<? extends E> elements) {
super.addAll(elements);
return this;
}
@Override public Builder<E> addAll(Iterator<? extends E> elements) {
super.addAll(elements);
return this;
}
@Override public ImmutableSortedSet<E> build() {
return copyOfInternal(comparator, contents.iterator());
}
}
}
| Java |
/*
* Copyright (C) 2007 The Guava Authors
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package com.google.common.collect;
import static com.google.common.base.Preconditions.checkArgument;
import static com.google.common.base.Preconditions.checkNotNull;
import static com.google.common.base.Preconditions.checkState;
import static com.google.common.collect.BstSide.LEFT;
import static com.google.common.collect.BstSide.RIGHT;
import com.google.common.annotations.GwtCompatible;
import com.google.common.primitives.Ints;
import java.io.Serializable;
import java.util.Comparator;
import java.util.ConcurrentModificationException;
import java.util.Iterator;
import javax.annotation.Nullable;
/**
* A multiset which maintains the ordering of its elements, according to either
* their natural order or an explicit {@link Comparator}. In all cases, this
* implementation uses {@link Comparable#compareTo} or {@link
* Comparator#compare} instead of {@link Object#equals} to determine
* equivalence of instances.
*
* <p><b>Warning:</b> The comparison must be <i>consistent with equals</i> as
* explained by the {@link Comparable} class specification. Otherwise, the
* resulting multiset will violate the {@link java.util.Collection} contract,
* which is specified in terms of {@link Object#equals}.
*
* <p>See the Guava User Guide article on <a href=
* "http://code.google.com/p/guava-libraries/wiki/NewCollectionTypesExplained#Multiset">
* {@code Multiset}</a>.
*
* @author Louis Wasserman
* @author Jared Levy
* @since 2.0 (imported from Google Collections Library)
*/
@GwtCompatible(emulated = true)
public final class TreeMultiset<E> extends AbstractSortedMultiset<E>
implements Serializable {
/**
* Creates a new, empty multiset, sorted according to the elements' natural
* order. All elements inserted into the multiset must implement the
* {@code Comparable} interface. Furthermore, all such elements must be
* <i>mutually comparable</i>: {@code e1.compareTo(e2)} must not throw a
* {@code ClassCastException} for any elements {@code e1} and {@code e2} in
* the multiset. If the user attempts to add an element to the multiset that
* violates this constraint (for example, the user attempts to add a string
* element to a set whose elements are integers), the {@code add(Object)}
* call will throw a {@code ClassCastException}.
*
* <p>The type specification is {@code <E extends Comparable>}, instead of the
* more specific {@code <E extends Comparable<? super E>>}, to support
* classes defined without generics.
*/
public static <E extends Comparable> TreeMultiset<E> create() {
return new TreeMultiset<E>(Ordering.natural());
}
/**
* Creates a new, empty multiset, sorted according to the specified
* comparator. All elements inserted into the multiset must be <i>mutually
* comparable</i> by the specified comparator: {@code comparator.compare(e1,
* e2)} must not throw a {@code ClassCastException} for any elements {@code
* e1} and {@code e2} in the multiset. If the user attempts to add an element
* to the multiset that violates this constraint, the {@code add(Object)} call
* will throw a {@code ClassCastException}.
*
* @param comparator the comparator that will be used to sort this multiset. A
* null value indicates that the elements' <i>natural ordering</i> should
* be used.
*/
@SuppressWarnings("unchecked")
public static <E> TreeMultiset<E> create(
@Nullable Comparator<? super E> comparator) {
return (comparator == null)
? new TreeMultiset<E>((Comparator) Ordering.natural())
: new TreeMultiset<E>(comparator);
}
/**
* Creates an empty multiset containing the given initial elements, sorted
* according to the elements' natural order.
*
* <p>This implementation is highly efficient when {@code elements} is itself
* a {@link Multiset}.
*
* <p>The type specification is {@code <E extends Comparable>}, instead of the
* more specific {@code <E extends Comparable<? super E>>}, to support
* classes defined without generics.
*/
public static <E extends Comparable> TreeMultiset<E> create(
Iterable<? extends E> elements) {
TreeMultiset<E> multiset = create();
Iterables.addAll(multiset, elements);
return multiset;
}
/**
* Returns an iterator over the elements contained in this collection.
*/
@Override
public Iterator<E> iterator() {
// Needed to avoid Javadoc bug.
return super.iterator();
}
private TreeMultiset(Comparator<? super E> comparator) {
super(comparator);
this.range = GeneralRange.all(comparator);
this.rootReference = new Reference<Node<E>>();
}
private TreeMultiset(GeneralRange<E> range, Reference<Node<E>> root) {
super(range.comparator());
this.range = range;
this.rootReference = root;
}
@SuppressWarnings("unchecked")
E checkElement(Object o) {
return (E) o;
}
private transient final GeneralRange<E> range;
private transient final Reference<Node<E>> rootReference;
static final class Reference<T> {
T value;
public Reference() {}
public T get() {
return value;
}
public boolean compareAndSet(T expected, T newValue) {
if (value == expected) {
value = newValue;
return true;
}
return false;
}
}
@Override
int distinctElements() {
Node<E> root = rootReference.get();
return Ints.checkedCast(BstRangeOps.totalInRange(distinctAggregate(), range, root));
}
@Override
public int size() {
Node<E> root = rootReference.get();
return Ints.saturatedCast(BstRangeOps.totalInRange(sizeAggregate(), range, root));
}
@Override
public int count(@Nullable Object element) {
try {
E e = checkElement(element);
if (range.contains(e)) {
Node<E> node = BstOperations.seek(comparator(), rootReference.get(), e);
return countOrZero(node);
}
return 0;
} catch (ClassCastException e) {
return 0;
} catch (NullPointerException e) {
return 0;
}
}
private int mutate(@Nullable E e, MultisetModifier modifier) {
BstMutationRule<E, Node<E>> mutationRule = BstMutationRule.createRule(
modifier,
BstCountBasedBalancePolicies.
<E, Node<E>>singleRebalancePolicy(distinctAggregate()),
nodeFactory());
BstMutationResult<E, Node<E>> mutationResult =
BstOperations.mutate(comparator(), mutationRule, rootReference.get(), e);
if (!rootReference.compareAndSet(
mutationResult.getOriginalRoot(), mutationResult.getChangedRoot())) {
throw new ConcurrentModificationException();
}
Node<E> original = mutationResult.getOriginalTarget();
return countOrZero(original);
}
@Override
public int add(E element, int occurrences) {
checkElement(element);
if (occurrences == 0) {
return count(element);
}
checkArgument(range.contains(element));
return mutate(element, new AddModifier(occurrences));
}
@Override
public int remove(@Nullable Object element, int occurrences) {
if (element == null) {
return 0;
} else if (occurrences == 0) {
return count(element);
}
try {
E e = checkElement(element);
return range.contains(e) ? mutate(e, new RemoveModifier(occurrences)) : 0;
} catch (ClassCastException e) {
return 0;
}
}
@Override
public boolean setCount(E element, int oldCount, int newCount) {
checkElement(element);
checkArgument(range.contains(element));
return mutate(element, new ConditionalSetCountModifier(oldCount, newCount))
== oldCount;
}
@Override
public int setCount(E element, int count) {
checkElement(element);
checkArgument(range.contains(element));
return mutate(element, new SetCountModifier(count));
}
private BstPathFactory<Node<E>, BstInOrderPath<Node<E>>> pathFactory() {
return BstInOrderPath.inOrderFactory();
}
@Override
Iterator<Entry<E>> entryIterator() {
Node<E> root = rootReference.get();
final BstInOrderPath<Node<E>> startingPath =
BstRangeOps.furthestPath(range, LEFT, pathFactory(), root);
return iteratorInDirection(startingPath, RIGHT);
}
@Override
Iterator<Entry<E>> descendingEntryIterator() {
Node<E> root = rootReference.get();
final BstInOrderPath<Node<E>> startingPath =
BstRangeOps.furthestPath(range, RIGHT, pathFactory(), root);
return iteratorInDirection(startingPath, LEFT);
}
private Iterator<Entry<E>> iteratorInDirection(
@Nullable BstInOrderPath<Node<E>> start, final BstSide direction) {
final Iterator<BstInOrderPath<Node<E>>> pathIterator =
new AbstractSequentialIterator<BstInOrderPath<Node<E>>>(start) {
@Override
protected BstInOrderPath<Node<E>> computeNext(BstInOrderPath<Node<E>> previous) {
if (!previous.hasNext(direction)) {
return null;
}
BstInOrderPath<Node<E>> next = previous.next(direction);
// TODO(user): only check against one side
return range.contains(next.getTip().getKey()) ? next : null;
}
};
return new Iterator<Entry<E>>() {
E toRemove = null;
@Override
public boolean hasNext() {
return pathIterator.hasNext();
}
@Override
public Entry<E> next() {
BstInOrderPath<Node<E>> path = pathIterator.next();
return new LiveEntry(
toRemove = path.getTip().getKey(), path.getTip().elemCount());
}
@Override
public void remove() {
checkState(toRemove != null);
setCount(toRemove, 0);
toRemove = null;
}
};
}
class LiveEntry extends Multisets.AbstractEntry<E> {
private Node<E> expectedRoot;
private final E element;
private int count;
private LiveEntry(E element, int count) {
this.expectedRoot = rootReference.get();
this.element = element;
this.count = count;
}
@Override
public E getElement() {
return element;
}
@Override
public int getCount() {
if (rootReference.get() == expectedRoot) {
return count;
} else {
// check for updates
expectedRoot = rootReference.get();
return count = TreeMultiset.this.count(element);
}
}
}
@Override
public void clear() {
Node<E> root = rootReference.get();
Node<E> cleared = BstRangeOps.minusRange(range,
BstCountBasedBalancePolicies.<E, Node<E>>fullRebalancePolicy(distinctAggregate()),
nodeFactory(), root);
if (!rootReference.compareAndSet(root, cleared)) {
throw new ConcurrentModificationException();
}
}
@Override
public SortedMultiset<E> headMultiset(E upperBound, BoundType boundType) {
checkNotNull(upperBound);
return new TreeMultiset<E>(
range.intersect(GeneralRange.upTo(comparator, upperBound, boundType)), rootReference);
}
@Override
public SortedMultiset<E> tailMultiset(E lowerBound, BoundType boundType) {
checkNotNull(lowerBound);
return new TreeMultiset<E>(
range.intersect(GeneralRange.downTo(comparator, lowerBound, boundType)), rootReference);
}
/**
* {@inheritDoc}
*
* @since 11.0
*/
@Override
public Comparator<? super E> comparator() {
return super.comparator();
}
private static final class Node<E> extends BstNode<E, Node<E>> implements Serializable {
private final long size;
private final int distinct;
private Node(E key, int elemCount, @Nullable Node<E> left,
@Nullable Node<E> right) {
super(key, left, right);
checkArgument(elemCount > 0);
this.size = (long) elemCount + sizeOrZero(left) + sizeOrZero(right);
this.distinct = 1 + distinctOrZero(left) + distinctOrZero(right);
}
int elemCount() {
long result = size - sizeOrZero(childOrNull(LEFT))
- sizeOrZero(childOrNull(RIGHT));
return Ints.checkedCast(result);
}
private Node(E key, int elemCount) {
this(key, elemCount, null, null);
}
private static final long serialVersionUID = 0;
}
private static long sizeOrZero(@Nullable Node<?> node) {
return (node == null) ? 0 : node.size;
}
private static int distinctOrZero(@Nullable Node<?> node) {
return (node == null) ? 0 : node.distinct;
}
private static int countOrZero(@Nullable Node<?> entry) {
return (entry == null) ? 0 : entry.elemCount();
}
@SuppressWarnings("unchecked")
private BstAggregate<Node<E>> distinctAggregate() {
return (BstAggregate) DISTINCT_AGGREGATE;
}
private static final BstAggregate<Node<Object>> DISTINCT_AGGREGATE =
new BstAggregate<Node<Object>>() {
@Override
public int entryValue(Node<Object> entry) {
return 1;
}
@Override
public long treeValue(@Nullable Node<Object> tree) {
return distinctOrZero(tree);
}
};
@SuppressWarnings("unchecked")
private BstAggregate<Node<E>> sizeAggregate() {
return (BstAggregate) SIZE_AGGREGATE;
}
private static final BstAggregate<Node<Object>> SIZE_AGGREGATE =
new BstAggregate<Node<Object>>() {
@Override
public int entryValue(Node<Object> entry) {
return entry.elemCount();
}
@Override
public long treeValue(@Nullable Node<Object> tree) {
return sizeOrZero(tree);
}
};
@SuppressWarnings("unchecked")
private BstNodeFactory<Node<E>> nodeFactory() {
return (BstNodeFactory) NODE_FACTORY;
}
private static final BstNodeFactory<Node<Object>> NODE_FACTORY =
new BstNodeFactory<Node<Object>>() {
@Override
public Node<Object> createNode(Node<Object> source, @Nullable Node<Object> left,
@Nullable Node<Object> right) {
return new Node<Object>(source.getKey(), source.elemCount(), left, right);
}
};
private abstract class MultisetModifier implements BstModifier<E, Node<E>> {
abstract int newCount(int oldCount);
@Nullable
@Override
public BstModificationResult<Node<E>> modify(E key, @Nullable Node<E> originalEntry) {
int oldCount = countOrZero(originalEntry);
int newCount = newCount(oldCount);
if (oldCount == newCount) {
return BstModificationResult.identity(originalEntry);
} else if (newCount == 0) {
return BstModificationResult.rebalancingChange(originalEntry, null);
} else if (oldCount == 0) {
return BstModificationResult.rebalancingChange(null, new Node<E>(key, newCount));
} else {
return BstModificationResult.rebuildingChange(originalEntry,
new Node<E>(originalEntry.getKey(), newCount));
}
}
}
private final class AddModifier extends MultisetModifier {
private final int countToAdd;
private AddModifier(int countToAdd) {
checkArgument(countToAdd > 0);
this.countToAdd = countToAdd;
}
@Override
int newCount(int oldCount) {
checkArgument(countToAdd <= Integer.MAX_VALUE - oldCount, "Cannot add this many elements");
return oldCount + countToAdd;
}
}
private final class RemoveModifier extends MultisetModifier {
private final int countToRemove;
private RemoveModifier(int countToRemove) {
checkArgument(countToRemove > 0);
this.countToRemove = countToRemove;
}
@Override
int newCount(int oldCount) {
return Math.max(0, oldCount - countToRemove);
}
}
private final class SetCountModifier extends MultisetModifier {
private final int countToSet;
private SetCountModifier(int countToSet) {
checkArgument(countToSet >= 0);
this.countToSet = countToSet;
}
@Override
int newCount(int oldCount) {
return countToSet;
}
}
private final class ConditionalSetCountModifier extends MultisetModifier {
private final int expectedCount;
private final int setCount;
private ConditionalSetCountModifier(int expectedCount, int setCount) {
checkArgument(setCount >= 0 & expectedCount >= 0);
this.expectedCount = expectedCount;
this.setCount = setCount;
}
@Override
int newCount(int oldCount) {
return (oldCount == expectedCount) ? setCount : oldCount;
}
}
/*
* TODO(jlevy): Decide whether entrySet() should return entries with an
* equals() method that calls the comparator to compare the two keys. If that
* change is made, AbstractMultiset.equals() can simply check whether two
* multisets have equal entry sets.
*/
}
| Java |
/*
* Copyright (C) 2009 The Guava Authors
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package com.google.common.collect;
import static com.google.common.base.Preconditions.checkArgument;
import java.util.Set;
/**
* GWT emulation of {@link RegularImmutableSet}.
*
* @author Hayward Chan
*/
final class RegularImmutableSet<E> extends ImmutableSet<E> {
RegularImmutableSet(Set<E> delegate) {
super(delegate);
// Required for GWT deserialization because the server-side implementation
// requires this.
checkArgument(delegate.size() >= 2);
}
}
| Java |
/*
* Copyright (C) 2009 The Guava Authors
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package com.google.common.collect;
import java.util.Map;
/**
* GWt emulation of {@link RegularImmutableMap}.
*
* @author Hayward Chan
*/
final class RegularImmutableMap<K, V> extends ImmutableMap<K, V> {
RegularImmutableMap(Map<? extends K, ? extends V> delegate) {
super(delegate);
}
RegularImmutableMap(Entry<? extends K, ? extends V>... entries) {
super(entries);
}
}
| Java |
/*
* Copyright (C) 2007 The Guava Authors
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package com.google.common.collect;
import static com.google.common.base.Preconditions.checkArgument;
import static com.google.common.base.Preconditions.checkNotNull;
import com.google.common.annotations.Beta;
import com.google.common.annotations.GwtCompatible;
import com.google.common.base.Equivalence;
import com.google.common.base.Equivalences;
import com.google.common.base.Function;
import com.google.common.base.Joiner.MapJoiner;
import com.google.common.base.Objects;
import com.google.common.base.Preconditions;
import com.google.common.base.Predicate;
import com.google.common.base.Predicates;
import com.google.common.collect.MapDifference.ValueDifference;
import com.google.common.primitives.Ints;
import java.io.Serializable;
import java.util.AbstractCollection;
import java.util.AbstractMap;
import java.util.AbstractSet;
import java.util.Collection;
import java.util.Collections;
import java.util.Comparator;
import java.util.EnumMap;
import java.util.HashMap;
import java.util.IdentityHashMap;
import java.util.Iterator;
import java.util.LinkedHashMap;
import java.util.Map;
import java.util.Map.Entry;
import java.util.Set;
import java.util.SortedMap;
import java.util.TreeMap;
import java.util.concurrent.ConcurrentMap;
import javax.annotation.Nullable;
/**
* Static utility methods pertaining to {@link Map} instances (including instances of
* {@link SortedMap}, {@link BiMap}, etc.). Also see this class's counterparts
* {@link Lists}, {@link Sets} and {@link Queues}.
*
* <p>See the Guava User Guide article on <a href=
* "http://code.google.com/p/guava-libraries/wiki/CollectionUtilitiesExplained#Maps">
* {@code Maps}</a>.
*
* @author Kevin Bourrillion
* @author Mike Bostock
* @author Isaac Shum
* @author Louis Wasserman
* @since 2.0 (imported from Google Collections Library)
*/
@GwtCompatible(emulated = true)
public final class Maps {
private Maps() {}
/**
* Creates a <i>mutable</i>, empty {@code HashMap} instance.
*
* <p><b>Note:</b> if mutability is not required, use {@link
* ImmutableMap#of()} instead.
*
* <p><b>Note:</b> if {@code K} is an {@code enum} type, use {@link
* #newEnumMap} instead.
*
* @return a new, empty {@code HashMap}
*/
public static <K, V> HashMap<K, V> newHashMap() {
return new HashMap<K, V>();
}
/**
* Creates a {@code HashMap} instance, with a high enough "initial capacity"
* that it <i>should</i> hold {@code expectedSize} elements without growth.
* This behavior cannot be broadly guaranteed, but it is observed to be true
* for OpenJDK 1.6. It also can't be guaranteed that the method isn't
* inadvertently <i>oversizing</i> the returned map.
*
* @param expectedSize the number of elements you expect to add to the
* returned map
* @return a new, empty {@code HashMap} with enough capacity to hold {@code
* expectedSize} elements without resizing
* @throws IllegalArgumentException if {@code expectedSize} is negative
*/
public static <K, V> HashMap<K, V> newHashMapWithExpectedSize(
int expectedSize) {
return new HashMap<K, V>(capacity(expectedSize));
}
/**
* Returns a capacity that is sufficient to keep the map from being resized as
* long as it grows no larger than expectedSize and the load factor is >= its
* default (0.75).
*/
static int capacity(int expectedSize) {
if (expectedSize < 3) {
checkArgument(expectedSize >= 0);
return expectedSize + 1;
}
if (expectedSize < Ints.MAX_POWER_OF_TWO) {
return expectedSize + expectedSize / 3;
}
return Integer.MAX_VALUE; // any large value
}
/**
* Creates a <i>mutable</i> {@code HashMap} instance with the same mappings as
* the specified map.
*
* <p><b>Note:</b> if mutability is not required, use {@link
* ImmutableMap#copyOf(Map)} instead.
*
* <p><b>Note:</b> if {@code K} is an {@link Enum} type, use {@link
* #newEnumMap} instead.
*
* @param map the mappings to be placed in the new map
* @return a new {@code HashMap} initialized with the mappings from {@code
* map}
*/
public static <K, V> HashMap<K, V> newHashMap(
Map<? extends K, ? extends V> map) {
return new HashMap<K, V>(map);
}
/**
* Creates a <i>mutable</i>, empty, insertion-ordered {@code LinkedHashMap}
* instance.
*
* <p><b>Note:</b> if mutability is not required, use {@link
* ImmutableMap#of()} instead.
*
* @return a new, empty {@code LinkedHashMap}
*/
public static <K, V> LinkedHashMap<K, V> newLinkedHashMap() {
return new LinkedHashMap<K, V>();
}
/**
* Creates a <i>mutable</i>, insertion-ordered {@code LinkedHashMap} instance
* with the same mappings as the specified map.
*
* <p><b>Note:</b> if mutability is not required, use {@link
* ImmutableMap#copyOf(Map)} instead.
*
* @param map the mappings to be placed in the new map
* @return a new, {@code LinkedHashMap} initialized with the mappings from
* {@code map}
*/
public static <K, V> LinkedHashMap<K, V> newLinkedHashMap(
Map<? extends K, ? extends V> map) {
return new LinkedHashMap<K, V>(map);
}
/**
* Returns a general-purpose instance of {@code ConcurrentMap}, which supports
* all optional operations of the ConcurrentMap interface. It does not permit
* null keys or values. It is serializable.
*
* <p>This is currently accomplished by calling {@link MapMaker#makeMap()}.
*
* <p>It is preferable to use {@code MapMaker} directly (rather than through
* this method), as it presents numerous useful configuration options,
* such as the concurrency level, load factor, key/value reference types,
* and value computation.
*
* @return a new, empty {@code ConcurrentMap}
* @since 3.0
*/
public static <K, V> ConcurrentMap<K, V> newConcurrentMap() {
return new MapMaker().<K, V>makeMap();
}
/**
* Creates a <i>mutable</i>, empty {@code TreeMap} instance using the natural
* ordering of its elements.
*
* <p><b>Note:</b> if mutability is not required, use {@link
* ImmutableSortedMap#of()} instead.
*
* @return a new, empty {@code TreeMap}
*/
public static <K extends Comparable, V> TreeMap<K, V> newTreeMap() {
return new TreeMap<K, V>();
}
/**
* Creates a <i>mutable</i> {@code TreeMap} instance with the same mappings as
* the specified map and using the same ordering as the specified map.
*
* <p><b>Note:</b> if mutability is not required, use {@link
* ImmutableSortedMap#copyOfSorted(SortedMap)} instead.
*
* @param map the sorted map whose mappings are to be placed in the new map
* and whose comparator is to be used to sort the new map
* @return a new {@code TreeMap} initialized with the mappings from {@code
* map} and using the comparator of {@code map}
*/
public static <K, V> TreeMap<K, V> newTreeMap(SortedMap<K, ? extends V> map) {
return new TreeMap<K, V>(map);
}
/**
* Creates a <i>mutable</i>, empty {@code TreeMap} instance using the given
* comparator.
*
* <p><b>Note:</b> if mutability is not required, use {@code
* ImmutableSortedMap.orderedBy(comparator).build()} instead.
*
* @param comparator the comparator to sort the keys with
* @return a new, empty {@code TreeMap}
*/
public static <C, K extends C, V> TreeMap<K, V> newTreeMap(
@Nullable Comparator<C> comparator) {
// Ideally, the extra type parameter "C" shouldn't be necessary. It is a
// work-around of a compiler type inference quirk that prevents the
// following code from being compiled:
// Comparator<Class<?>> comparator = null;
// Map<Class<? extends Throwable>, String> map = newTreeMap(comparator);
return new TreeMap<K, V>(comparator);
}
/**
* Creates an {@code EnumMap} instance.
*
* @param type the key type for this map
* @return a new, empty {@code EnumMap}
*/
public static <K extends Enum<K>, V> EnumMap<K, V> newEnumMap(Class<K> type) {
return new EnumMap<K, V>(checkNotNull(type));
}
/**
* Creates an {@code EnumMap} with the same mappings as the specified map.
*
* @param map the map from which to initialize this {@code EnumMap}
* @return a new {@code EnumMap} initialized with the mappings from {@code
* map}
* @throws IllegalArgumentException if {@code m} is not an {@code EnumMap}
* instance and contains no mappings
*/
public static <K extends Enum<K>, V> EnumMap<K, V> newEnumMap(
Map<K, ? extends V> map) {
return new EnumMap<K, V>(map);
}
/**
* Creates an {@code IdentityHashMap} instance.
*
* @return a new, empty {@code IdentityHashMap}
*/
public static <K, V> IdentityHashMap<K, V> newIdentityHashMap() {
return new IdentityHashMap<K, V>();
}
/**
* Computes the difference between two maps. This difference is an immutable
* snapshot of the state of the maps at the time this method is called. It
* will never change, even if the maps change at a later time.
*
* <p>Since this method uses {@code HashMap} instances internally, the keys of
* the supplied maps must be well-behaved with respect to
* {@link Object#equals} and {@link Object#hashCode}.
*
* <p><b>Note:</b>If you only need to know whether two maps have the same
* mappings, call {@code left.equals(right)} instead of this method.
*
* @param left the map to treat as the "left" map for purposes of comparison
* @param right the map to treat as the "right" map for purposes of comparison
* @return the difference between the two maps
*/
@SuppressWarnings("unchecked")
public static <K, V> MapDifference<K, V> difference(
Map<? extends K, ? extends V> left, Map<? extends K, ? extends V> right) {
if (left instanceof SortedMap) {
SortedMap<K, ? extends V> sortedLeft = (SortedMap<K, ? extends V>) left;
SortedMapDifference<K, V> result = difference(sortedLeft, right);
return result;
}
return difference(left, right, Equivalences.equals());
}
/**
* Computes the difference between two maps. This difference is an immutable
* snapshot of the state of the maps at the time this method is called. It
* will never change, even if the maps change at a later time.
*
* <p>Values are compared using a provided equivalence, in the case of
* equality, the value on the 'left' is returned in the difference.
*
* <p>Since this method uses {@code HashMap} instances internally, the keys of
* the supplied maps must be well-behaved with respect to
* {@link Object#equals} and {@link Object#hashCode}.
*
* @param left the map to treat as the "left" map for purposes of comparison
* @param right the map to treat as the "right" map for purposes of comparison
* @param valueEquivalence the equivalence relationship to use to compare
* values
* @return the difference between the two maps
* @since 10.0
*/
@Beta
public static <K, V> MapDifference<K, V> difference(
Map<? extends K, ? extends V> left, Map<? extends K, ? extends V> right,
Equivalence<? super V> valueEquivalence) {
Preconditions.checkNotNull(valueEquivalence);
Map<K, V> onlyOnLeft = newHashMap();
Map<K, V> onlyOnRight = new HashMap<K, V>(right); // will whittle it down
Map<K, V> onBoth = newHashMap();
Map<K, MapDifference.ValueDifference<V>> differences = newHashMap();
boolean eq = true;
for (Entry<? extends K, ? extends V> entry : left.entrySet()) {
K leftKey = entry.getKey();
V leftValue = entry.getValue();
if (right.containsKey(leftKey)) {
V rightValue = onlyOnRight.remove(leftKey);
if (valueEquivalence.equivalent(leftValue, rightValue)) {
onBoth.put(leftKey, leftValue);
} else {
eq = false;
differences.put(
leftKey, ValueDifferenceImpl.create(leftValue, rightValue));
}
} else {
eq = false;
onlyOnLeft.put(leftKey, leftValue);
}
}
boolean areEqual = eq && onlyOnRight.isEmpty();
return mapDifference(
areEqual, onlyOnLeft, onlyOnRight, onBoth, differences);
}
private static <K, V> MapDifference<K, V> mapDifference(boolean areEqual,
Map<K, V> onlyOnLeft, Map<K, V> onlyOnRight, Map<K, V> onBoth,
Map<K, ValueDifference<V>> differences) {
return new MapDifferenceImpl<K, V>(areEqual,
Collections.unmodifiableMap(onlyOnLeft),
Collections.unmodifiableMap(onlyOnRight),
Collections.unmodifiableMap(onBoth),
Collections.unmodifiableMap(differences));
}
static class MapDifferenceImpl<K, V> implements MapDifference<K, V> {
final boolean areEqual;
final Map<K, V> onlyOnLeft;
final Map<K, V> onlyOnRight;
final Map<K, V> onBoth;
final Map<K, ValueDifference<V>> differences;
MapDifferenceImpl(boolean areEqual, Map<K, V> onlyOnLeft,
Map<K, V> onlyOnRight, Map<K, V> onBoth,
Map<K, ValueDifference<V>> differences) {
this.areEqual = areEqual;
this.onlyOnLeft = onlyOnLeft;
this.onlyOnRight = onlyOnRight;
this.onBoth = onBoth;
this.differences = differences;
}
@Override
public boolean areEqual() {
return areEqual;
}
@Override
public Map<K, V> entriesOnlyOnLeft() {
return onlyOnLeft;
}
@Override
public Map<K, V> entriesOnlyOnRight() {
return onlyOnRight;
}
@Override
public Map<K, V> entriesInCommon() {
return onBoth;
}
@Override
public Map<K, ValueDifference<V>> entriesDiffering() {
return differences;
}
@Override public boolean equals(Object object) {
if (object == this) {
return true;
}
if (object instanceof MapDifference) {
MapDifference<?, ?> other = (MapDifference<?, ?>) object;
return entriesOnlyOnLeft().equals(other.entriesOnlyOnLeft())
&& entriesOnlyOnRight().equals(other.entriesOnlyOnRight())
&& entriesInCommon().equals(other.entriesInCommon())
&& entriesDiffering().equals(other.entriesDiffering());
}
return false;
}
@Override public int hashCode() {
return Objects.hashCode(entriesOnlyOnLeft(), entriesOnlyOnRight(),
entriesInCommon(), entriesDiffering());
}
@Override public String toString() {
if (areEqual) {
return "equal";
}
StringBuilder result = new StringBuilder("not equal");
if (!onlyOnLeft.isEmpty()) {
result.append(": only on left=").append(onlyOnLeft);
}
if (!onlyOnRight.isEmpty()) {
result.append(": only on right=").append(onlyOnRight);
}
if (!differences.isEmpty()) {
result.append(": value differences=").append(differences);
}
return result.toString();
}
}
static class ValueDifferenceImpl<V>
implements MapDifference.ValueDifference<V> {
private final V left;
private final V right;
static <V> ValueDifference<V> create(@Nullable V left, @Nullable V right) {
return new ValueDifferenceImpl<V>(left, right);
}
private ValueDifferenceImpl(@Nullable V left, @Nullable V right) {
this.left = left;
this.right = right;
}
@Override
public V leftValue() {
return left;
}
@Override
public V rightValue() {
return right;
}
@Override public boolean equals(@Nullable Object object) {
if (object instanceof MapDifference.ValueDifference<?>) {
MapDifference.ValueDifference<?> that =
(MapDifference.ValueDifference<?>) object;
return Objects.equal(this.left, that.leftValue())
&& Objects.equal(this.right, that.rightValue());
}
return false;
}
@Override public int hashCode() {
return Objects.hashCode(left, right);
}
@Override public String toString() {
return "(" + left + ", " + right + ")";
}
}
/**
* Computes the difference between two sorted maps, using the comparator of
* the left map, or {@code Ordering.natural()} if the left map uses the
* natural ordering of its elements. This difference is an immutable snapshot
* of the state of the maps at the time this method is called. It will never
* change, even if the maps change at a later time.
*
* <p>Since this method uses {@code TreeMap} instances internally, the keys of
* the right map must all compare as distinct according to the comparator
* of the left map.
*
* <p><b>Note:</b>If you only need to know whether two sorted maps have the
* same mappings, call {@code left.equals(right)} instead of this method.
*
* @param left the map to treat as the "left" map for purposes of comparison
* @param right the map to treat as the "right" map for purposes of comparison
* @return the difference between the two maps
* @since 11.0
*/
@Beta
public static <K, V> SortedMapDifference<K, V> difference(
SortedMap<K, ? extends V> left, Map<? extends K, ? extends V> right) {
checkNotNull(left);
checkNotNull(right);
Comparator<? super K> comparator = orNaturalOrder(left.comparator());
SortedMap<K, V> onlyOnLeft = Maps.newTreeMap(comparator);
SortedMap<K, V> onlyOnRight = Maps.newTreeMap(comparator);
onlyOnRight.putAll(right); // will whittle it down
SortedMap<K, V> onBoth = Maps.newTreeMap(comparator);
SortedMap<K, MapDifference.ValueDifference<V>> differences =
Maps.newTreeMap(comparator);
boolean eq = true;
for (Entry<? extends K, ? extends V> entry : left.entrySet()) {
K leftKey = entry.getKey();
V leftValue = entry.getValue();
if (right.containsKey(leftKey)) {
V rightValue = onlyOnRight.remove(leftKey);
if (Objects.equal(leftValue, rightValue)) {
onBoth.put(leftKey, leftValue);
} else {
eq = false;
differences.put(
leftKey, ValueDifferenceImpl.create(leftValue, rightValue));
}
} else {
eq = false;
onlyOnLeft.put(leftKey, leftValue);
}
}
boolean areEqual = eq && onlyOnRight.isEmpty();
return sortedMapDifference(
areEqual, onlyOnLeft, onlyOnRight, onBoth, differences);
}
private static <K, V> SortedMapDifference<K, V> sortedMapDifference(
boolean areEqual, SortedMap<K, V> onlyOnLeft, SortedMap<K, V> onlyOnRight,
SortedMap<K, V> onBoth, SortedMap<K, ValueDifference<V>> differences) {
return new SortedMapDifferenceImpl<K, V>(areEqual,
Collections.unmodifiableSortedMap(onlyOnLeft),
Collections.unmodifiableSortedMap(onlyOnRight),
Collections.unmodifiableSortedMap(onBoth),
Collections.unmodifiableSortedMap(differences));
}
static class SortedMapDifferenceImpl<K, V> extends MapDifferenceImpl<K, V>
implements SortedMapDifference<K, V> {
SortedMapDifferenceImpl(boolean areEqual, SortedMap<K, V> onlyOnLeft,
SortedMap<K, V> onlyOnRight, SortedMap<K, V> onBoth,
SortedMap<K, ValueDifference<V>> differences) {
super(areEqual, onlyOnLeft, onlyOnRight, onBoth, differences);
}
@Override public SortedMap<K, ValueDifference<V>> entriesDiffering() {
return (SortedMap<K, ValueDifference<V>>) super.entriesDiffering();
}
@Override public SortedMap<K, V> entriesInCommon() {
return (SortedMap<K, V>) super.entriesInCommon();
}
@Override public SortedMap<K, V> entriesOnlyOnLeft() {
return (SortedMap<K, V>) super.entriesOnlyOnLeft();
}
@Override public SortedMap<K, V> entriesOnlyOnRight() {
return (SortedMap<K, V>) super.entriesOnlyOnRight();
}
}
/**
* Returns the specified comparator if not null; otherwise returns {@code
* Ordering.natural()}. This method is an abomination of generics; the only
* purpose of this method is to contain the ugly type-casting in one place.
*/
@SuppressWarnings("unchecked")
static <E> Comparator<? super E> orNaturalOrder(
@Nullable Comparator<? super E> comparator) {
if (comparator != null) { // can't use ? : because of javac bug 5080917
return comparator;
}
return (Comparator<E>) Ordering.natural();
}
/**
* Returns an immutable map for which the {@link Map#values} are the given
* elements in the given order, and each key is the product of invoking a
* supplied function on its corresponding value.
*
* @param values the values to use when constructing the {@code Map}
* @param keyFunction the function used to produce the key for each value
* @return a map mapping the result of evaluating the function {@code
* keyFunction} on each value in the input collection to that value
* @throws IllegalArgumentException if {@code keyFunction} produces the same
* key for more than one value in the input collection
* @throws NullPointerException if any elements of {@code values} is null, or
* if {@code keyFunction} produces {@code null} for any value
*/
public static <K, V> ImmutableMap<K, V> uniqueIndex(
Iterable<V> values, Function<? super V, K> keyFunction) {
return uniqueIndex(values.iterator(), keyFunction);
}
/**
* <b>Deprecated.</b>
*
* @since 10.0
* @deprecated use {@link #uniqueIndex(Iterator, Function)} by casting {@code
* values} to {@code Iterator<V>}, or better yet, by implementing only
* {@code Iterator} and not {@code Iterable}. <b>This method is scheduled
* for deletion in March 2012.</b>
*/
@Beta
@Deprecated
public static <K, V, I extends Object & Iterable<V> & Iterator<V>>
ImmutableMap<K, V> uniqueIndex(
I values, Function<? super V, K> keyFunction) {
Iterable<V> valuesIterable = checkNotNull(values);
return uniqueIndex(valuesIterable, keyFunction);
}
/**
* Returns an immutable map for which the {@link Map#values} are the given
* elements in the given order, and each key is the product of invoking a
* supplied function on its corresponding value.
*
* @param values the values to use when constructing the {@code Map}
* @param keyFunction the function used to produce the key for each value
* @return a map mapping the result of evaluating the function {@code
* keyFunction} on each value in the input collection to that value
* @throws IllegalArgumentException if {@code keyFunction} produces the same
* key for more than one value in the input collection
* @throws NullPointerException if any elements of {@code values} is null, or
* if {@code keyFunction} produces {@code null} for any value
* @since 10.0
*/
public static <K, V> ImmutableMap<K, V> uniqueIndex(
Iterator<V> values, Function<? super V, K> keyFunction) {
checkNotNull(keyFunction);
ImmutableMap.Builder<K, V> builder = ImmutableMap.builder();
while (values.hasNext()) {
V value = values.next();
builder.put(keyFunction.apply(value), value);
}
return builder.build();
}
/**
* Returns an immutable map entry with the specified key and value. The {@link
* Entry#setValue} operation throws an {@link UnsupportedOperationException}.
*
* <p>The returned entry is serializable.
*
* @param key the key to be associated with the returned entry
* @param value the value to be associated with the returned entry
*/
@GwtCompatible(serializable = true)
public static <K, V> Entry<K, V> immutableEntry(
@Nullable K key, @Nullable V value) {
return new ImmutableEntry<K, V>(key, value);
}
/**
* Returns an unmodifiable view of the specified set of entries. The {@link
* Entry#setValue} operation throws an {@link UnsupportedOperationException},
* as do any operations that would modify the returned set.
*
* @param entrySet the entries for which to return an unmodifiable view
* @return an unmodifiable view of the entries
*/
static <K, V> Set<Entry<K, V>> unmodifiableEntrySet(
Set<Entry<K, V>> entrySet) {
return new UnmodifiableEntrySet<K, V>(
Collections.unmodifiableSet(entrySet));
}
/**
* Returns an unmodifiable view of the specified map entry. The {@link
* Entry#setValue} operation throws an {@link UnsupportedOperationException}.
* This also has the side-effect of redefining {@code equals} to comply with
* the Entry contract, to avoid a possible nefarious implementation of equals.
*
* @param entry the entry for which to return an unmodifiable view
* @return an unmodifiable view of the entry
*/
static <K, V> Entry<K, V> unmodifiableEntry(final Entry<K, V> entry) {
checkNotNull(entry);
return new AbstractMapEntry<K, V>() {
@Override public K getKey() {
return entry.getKey();
}
@Override public V getValue() {
return entry.getValue();
}
};
}
/** @see Multimaps#unmodifiableEntries */
static class UnmodifiableEntries<K, V>
extends ForwardingCollection<Entry<K, V>> {
private final Collection<Entry<K, V>> entries;
UnmodifiableEntries(Collection<Entry<K, V>> entries) {
this.entries = entries;
}
@Override protected Collection<Entry<K, V>> delegate() {
return entries;
}
@Override public Iterator<Entry<K, V>> iterator() {
final Iterator<Entry<K, V>> delegate = super.iterator();
return new ForwardingIterator<Entry<K, V>>() {
@Override public Entry<K, V> next() {
return unmodifiableEntry(super.next());
}
@Override public void remove() {
throw new UnsupportedOperationException();
}
@Override protected Iterator<Entry<K, V>> delegate() {
return delegate;
}
};
}
// See java.util.Collections.UnmodifiableEntrySet for details on attacks.
@Override public boolean add(Entry<K, V> element) {
throw new UnsupportedOperationException();
}
@Override public boolean addAll(
Collection<? extends Entry<K, V>> collection) {
throw new UnsupportedOperationException();
}
@Override public void clear() {
throw new UnsupportedOperationException();
}
@Override public boolean remove(Object object) {
throw new UnsupportedOperationException();
}
@Override public boolean removeAll(Collection<?> collection) {
throw new UnsupportedOperationException();
}
@Override public boolean retainAll(Collection<?> collection) {
throw new UnsupportedOperationException();
}
@Override public Object[] toArray() {
return standardToArray();
}
@Override public <T> T[] toArray(T[] array) {
return standardToArray(array);
}
}
/** @see Maps#unmodifiableEntrySet(Set) */
static class UnmodifiableEntrySet<K, V>
extends UnmodifiableEntries<K, V> implements Set<Entry<K, V>> {
UnmodifiableEntrySet(Set<Entry<K, V>> entries) {
super(entries);
}
// See java.util.Collections.UnmodifiableEntrySet for details on attacks.
@Override public boolean equals(@Nullable Object object) {
return Sets.equalsImpl(this, object);
}
@Override public int hashCode() {
return Sets.hashCodeImpl(this);
}
}
/**
* Returns a synchronized (thread-safe) bimap backed by the specified bimap.
* In order to guarantee serial access, it is critical that <b>all</b> access
* to the backing bimap is accomplished through the returned bimap.
*
* <p>It is imperative that the user manually synchronize on the returned map
* when accessing any of its collection views: <pre> {@code
*
* BiMap<Long, String> map = Maps.synchronizedBiMap(
* HashBiMap.<Long, String>create());
* ...
* Set<Long> set = map.keySet(); // Needn't be in synchronized block
* ...
* synchronized (map) { // Synchronizing on map, not set!
* Iterator<Long> it = set.iterator(); // Must be in synchronized block
* while (it.hasNext()) {
* foo(it.next());
* }
* }}</pre>
*
* Failure to follow this advice may result in non-deterministic behavior.
*
* <p>The returned bimap will be serializable if the specified bimap is
* serializable.
*
* @param bimap the bimap to be wrapped in a synchronized view
* @return a sychronized view of the specified bimap
*/
public static <K, V> BiMap<K, V> synchronizedBiMap(BiMap<K, V> bimap) {
return Synchronized.biMap(bimap, null);
}
/**
* Returns an unmodifiable view of the specified bimap. This method allows
* modules to provide users with "read-only" access to internal bimaps. Query
* operations on the returned bimap "read through" to the specified bimap, and
* attempts to modify the returned map, whether direct or via its collection
* views, result in an {@code UnsupportedOperationException}.
*
* <p>The returned bimap will be serializable if the specified bimap is
* serializable.
*
* @param bimap the bimap for which an unmodifiable view is to be returned
* @return an unmodifiable view of the specified bimap
*/
public static <K, V> BiMap<K, V> unmodifiableBiMap(
BiMap<? extends K, ? extends V> bimap) {
return new UnmodifiableBiMap<K, V>(bimap, null);
}
/** @see Maps#unmodifiableBiMap(BiMap) */
private static class UnmodifiableBiMap<K, V>
extends ForwardingMap<K, V> implements BiMap<K, V>, Serializable {
final Map<K, V> unmodifiableMap;
final BiMap<? extends K, ? extends V> delegate;
transient BiMap<V, K> inverse;
transient Set<V> values;
UnmodifiableBiMap(BiMap<? extends K, ? extends V> delegate,
@Nullable BiMap<V, K> inverse) {
unmodifiableMap = Collections.unmodifiableMap(delegate);
this.delegate = delegate;
this.inverse = inverse;
}
@Override protected Map<K, V> delegate() {
return unmodifiableMap;
}
@Override
public V forcePut(K key, V value) {
throw new UnsupportedOperationException();
}
@Override
public BiMap<V, K> inverse() {
BiMap<V, K> result = inverse;
return (result == null)
? inverse = new UnmodifiableBiMap<V, K>(delegate.inverse(), this)
: result;
}
@Override public Set<V> values() {
Set<V> result = values;
return (result == null)
? values = Collections.unmodifiableSet(delegate.values())
: result;
}
private static final long serialVersionUID = 0;
}
/**
* Returns a view of a map where each value is transformed by a function. All
* other properties of the map, such as iteration order, are left intact. For
* example, the code: <pre> {@code
*
* Map<String, Integer> map = ImmutableMap.of("a", 4, "b", 9);
* Function<Integer, Double> sqrt =
* new Function<Integer, Double>() {
* public Double apply(Integer in) {
* return Math.sqrt((int) in);
* }
* };
* Map<String, Double> transformed = Maps.transformValues(map, sqrt);
* System.out.println(transformed);}</pre>
*
* ... prints {@code {a=2.0, b=3.0}}.
*
* <p>Changes in the underlying map are reflected in this view. Conversely,
* this view supports removal operations, and these are reflected in the
* underlying map.
*
* <p>It's acceptable for the underlying map to contain null keys, and even
* null values provided that the function is capable of accepting null input.
* The transformed map might contain null values, if the function sometimes
* gives a null result.
*
* <p>The returned map is not thread-safe or serializable, even if the
* underlying map is.
*
* <p>The function is applied lazily, invoked when needed. This is necessary
* for the returned map to be a view, but it means that the function will be
* applied many times for bulk operations like {@link Map#containsValue} and
* {@code Map.toString()}. For this to perform well, {@code function} should
* be fast. To avoid lazy evaluation when the returned map doesn't need to be
* a view, copy the returned map into a new map of your choosing.
*/
public static <K, V1, V2> Map<K, V2> transformValues(
Map<K, V1> fromMap, final Function<? super V1, V2> function) {
checkNotNull(function);
EntryTransformer<K, V1, V2> transformer =
new EntryTransformer<K, V1, V2>() {
@Override
public V2 transformEntry(K key, V1 value) {
return function.apply(value);
}
};
return transformEntries(fromMap, transformer);
}
/**
* Returns a view of a sorted map where each value is transformed by a
* function. All other properties of the map, such as iteration order, are
* left intact. For example, the code: <pre> {@code
*
* SortedMap<String, Integer> map = ImmutableSortedMap.of("a", 4, "b", 9);
* Function<Integer, Double> sqrt =
* new Function<Integer, Double>() {
* public Double apply(Integer in) {
* return Math.sqrt((int) in);
* }
* };
* SortedMap<String, Double> transformed =
* Maps.transformSortedValues(map, sqrt);
* System.out.println(transformed);}</pre>
*
* ... prints {@code {a=2.0, b=3.0}}.
*
* <p>Changes in the underlying map are reflected in this view. Conversely,
* this view supports removal operations, and these are reflected in the
* underlying map.
*
* <p>It's acceptable for the underlying map to contain null keys, and even
* null values provided that the function is capable of accepting null input.
* The transformed map might contain null values, if the function sometimes
* gives a null result.
*
* <p>The returned map is not thread-safe or serializable, even if the
* underlying map is.
*
* <p>The function is applied lazily, invoked when needed. This is necessary
* for the returned map to be a view, but it means that the function will be
* applied many times for bulk operations like {@link Map#containsValue} and
* {@code Map.toString()}. For this to perform well, {@code function} should
* be fast. To avoid lazy evaluation when the returned map doesn't need to be
* a view, copy the returned map into a new map of your choosing.
*
* @since 11.0
*/
@Beta
public static <K, V1, V2> SortedMap<K, V2> transformValues(
SortedMap<K, V1> fromMap, final Function<? super V1, V2> function) {
checkNotNull(function);
EntryTransformer<K, V1, V2> transformer =
new EntryTransformer<K, V1, V2>() {
@Override
public V2 transformEntry(K key, V1 value) {
return function.apply(value);
}
};
return transformEntries(fromMap, transformer);
}
/**
* Returns a view of a map whose values are derived from the original map's
* entries. In contrast to {@link #transformValues}, this method's
* entry-transformation logic may depend on the key as well as the value.
*
* <p>All other properties of the transformed map, such as iteration order,
* are left intact. For example, the code: <pre> {@code
*
* Map<String, Boolean> options =
* ImmutableMap.of("verbose", true, "sort", false);
* EntryTransformer<String, Boolean, String> flagPrefixer =
* new EntryTransformer<String, Boolean, String>() {
* public String transformEntry(String key, Boolean value) {
* return value ? key : "no" + key;
* }
* };
* Map<String, String> transformed =
* Maps.transformEntries(options, flagPrefixer);
* System.out.println(transformed);}</pre>
*
* ... prints {@code {verbose=verbose, sort=nosort}}.
*
* <p>Changes in the underlying map are reflected in this view. Conversely,
* this view supports removal operations, and these are reflected in the
* underlying map.
*
* <p>It's acceptable for the underlying map to contain null keys and null
* values provided that the transformer is capable of accepting null inputs.
* The transformed map might contain null values if the transformer sometimes
* gives a null result.
*
* <p>The returned map is not thread-safe or serializable, even if the
* underlying map is.
*
* <p>The transformer is applied lazily, invoked when needed. This is
* necessary for the returned map to be a view, but it means that the
* transformer will be applied many times for bulk operations like {@link
* Map#containsValue} and {@link Object#toString}. For this to perform well,
* {@code transformer} should be fast. To avoid lazy evaluation when the
* returned map doesn't need to be a view, copy the returned map into a new
* map of your choosing.
*
* <p><b>Warning:</b> This method assumes that for any instance {@code k} of
* {@code EntryTransformer} key type {@code K}, {@code k.equals(k2)} implies
* that {@code k2} is also of type {@code K}. Using an {@code
* EntryTransformer} key type for which this may not hold, such as {@code
* ArrayList}, may risk a {@code ClassCastException} when calling methods on
* the transformed map.
*
* @since 7.0
*/
public static <K, V1, V2> Map<K, V2> transformEntries(
Map<K, V1> fromMap,
EntryTransformer<? super K, ? super V1, V2> transformer) {
if (fromMap instanceof SortedMap) {
return transformEntries((SortedMap<K, V1>) fromMap, transformer);
}
return new TransformedEntriesMap<K, V1, V2>(fromMap, transformer);
}
/**
* Returns a view of a sorted map whose values are derived from the original
* sorted map's entries. In contrast to {@link #transformValues}, this
* method's entry-transformation logic may depend on the key as well as the
* value.
*
* <p>All other properties of the transformed map, such as iteration order,
* are left intact. For example, the code: <pre> {@code
*
* Map<String, Boolean> options =
* ImmutableSortedMap.of("verbose", true, "sort", false);
* EntryTransformer<String, Boolean, String> flagPrefixer =
* new EntryTransformer<String, Boolean, String>() {
* public String transformEntry(String key, Boolean value) {
* return value ? key : "yes" + key;
* }
* };
* SortedMap<String, String> transformed =
* LabsMaps.transformSortedEntries(options, flagPrefixer);
* System.out.println(transformed);}</pre>
*
* ... prints {@code {sort=yessort, verbose=verbose}}.
*
* <p>Changes in the underlying map are reflected in this view. Conversely,
* this view supports removal operations, and these are reflected in the
* underlying map.
*
* <p>It's acceptable for the underlying map to contain null keys and null
* values provided that the transformer is capable of accepting null inputs.
* The transformed map might contain null values if the transformer sometimes
* gives a null result.
*
* <p>The returned map is not thread-safe or serializable, even if the
* underlying map is.
*
* <p>The transformer is applied lazily, invoked when needed. This is
* necessary for the returned map to be a view, but it means that the
* transformer will be applied many times for bulk operations like {@link
* Map#containsValue} and {@link Object#toString}. For this to perform well,
* {@code transformer} should be fast. To avoid lazy evaluation when the
* returned map doesn't need to be a view, copy the returned map into a new
* map of your choosing.
*
* <p><b>Warning:</b> This method assumes that for any instance {@code k} of
* {@code EntryTransformer} key type {@code K}, {@code k.equals(k2)} implies
* that {@code k2} is also of type {@code K}. Using an {@code
* EntryTransformer} key type for which this may not hold, such as {@code
* ArrayList}, may risk a {@code ClassCastException} when calling methods on
* the transformed map.
*
* @since 11.0
*/
@Beta
public static <K, V1, V2> SortedMap<K, V2> transformEntries(
final SortedMap<K, V1> fromMap,
EntryTransformer<? super K, ? super V1, V2> transformer) {
return new TransformedEntriesSortedMap<K, V1, V2>(fromMap, transformer);
}
/**
* A transformation of the value of a key-value pair, using both key and value
* as inputs. To apply the transformation to a map, use
* {@link Maps#transformEntries(Map, EntryTransformer)}.
*
* @param <K> the key type of the input and output entries
* @param <V1> the value type of the input entry
* @param <V2> the value type of the output entry
* @since 7.0
*/
public interface EntryTransformer<K, V1, V2> {
/**
* Determines an output value based on a key-value pair. This method is
* <i>generally expected</i>, but not absolutely required, to have the
* following properties:
*
* <ul>
* <li>Its execution does not cause any observable side effects.
* <li>The computation is <i>consistent with equals</i>; that is,
* {@link Objects#equal Objects.equal}{@code (k1, k2) &&}
* {@link Objects#equal}{@code (v1, v2)} implies that {@code
* Objects.equal(transformer.transform(k1, v1),
* transformer.transform(k2, v2))}.
* </ul>
*
* @throws NullPointerException if the key or value is null and this
* transformer does not accept null arguments
*/
V2 transformEntry(@Nullable K key, @Nullable V1 value);
}
static class TransformedEntriesMap<K, V1, V2>
extends AbstractMap<K, V2> {
final Map<K, V1> fromMap;
final EntryTransformer<? super K, ? super V1, V2> transformer;
TransformedEntriesMap(
Map<K, V1> fromMap,
EntryTransformer<? super K, ? super V1, V2> transformer) {
this.fromMap = checkNotNull(fromMap);
this.transformer = checkNotNull(transformer);
}
@Override public int size() {
return fromMap.size();
}
@Override public boolean containsKey(Object key) {
return fromMap.containsKey(key);
}
// safe as long as the user followed the <b>Warning</b> in the javadoc
@SuppressWarnings("unchecked")
@Override public V2 get(Object key) {
V1 value = fromMap.get(key);
return (value != null || fromMap.containsKey(key))
? transformer.transformEntry((K) key, value)
: null;
}
// safe as long as the user followed the <b>Warning</b> in the javadoc
@SuppressWarnings("unchecked")
@Override public V2 remove(Object key) {
return fromMap.containsKey(key)
? transformer.transformEntry((K) key, fromMap.remove(key))
: null;
}
@Override public void clear() {
fromMap.clear();
}
@Override public Set<K> keySet() {
return fromMap.keySet();
}
Set<Entry<K, V2>> entrySet;
@Override public Set<Entry<K, V2>> entrySet() {
Set<Entry<K, V2>> result = entrySet;
if (result == null) {
entrySet = result = new EntrySet<K, V2>() {
@Override Map<K, V2> map() {
return TransformedEntriesMap.this;
}
@Override public Iterator<Entry<K, V2>> iterator() {
final Iterator<Entry<K, V1>> backingIterator =
fromMap.entrySet().iterator();
return Iterators.transform(backingIterator,
new Function<Entry<K, V1>, Entry<K, V2>>() {
@Override public Entry<K, V2> apply(Entry<K, V1> entry) {
return immutableEntry(
entry.getKey(),
transformer.transformEntry(entry.getKey(),
entry.getValue()));
}
});
}
};
}
return result;
}
Collection<V2> values;
@Override public Collection<V2> values() {
Collection<V2> result = values;
if (result == null) {
return values = new Values<K, V2>() {
@Override Map<K, V2> map() {
return TransformedEntriesMap.this;
}
};
}
return result;
}
}
static class TransformedEntriesSortedMap<K, V1, V2>
extends TransformedEntriesMap<K, V1, V2> implements SortedMap<K, V2> {
protected SortedMap<K, V1> fromMap() {
return (SortedMap<K, V1>) fromMap;
}
TransformedEntriesSortedMap(SortedMap<K, V1> fromMap,
EntryTransformer<? super K, ? super V1, V2> transformer) {
super(fromMap, transformer);
}
@Override public Comparator<? super K> comparator() {
return fromMap().comparator();
}
@Override public K firstKey() {
return fromMap().firstKey();
}
@Override public SortedMap<K, V2> headMap(K toKey) {
return transformEntries(fromMap().headMap(toKey), transformer);
}
@Override public K lastKey() {
return fromMap().lastKey();
}
@Override public SortedMap<K, V2> subMap(K fromKey, K toKey) {
return transformEntries(
fromMap().subMap(fromKey, toKey), transformer);
}
@Override public SortedMap<K, V2> tailMap(K fromKey) {
return transformEntries(fromMap().tailMap(fromKey), transformer);
}
}
/**
* Returns a map containing the mappings in {@code unfiltered} whose keys
* satisfy a predicate. The returned map is a live view of {@code unfiltered};
* changes to one affect the other.
*
* <p>The resulting map's {@code keySet()}, {@code entrySet()}, and {@code
* values()} views have iterators that don't support {@code remove()}, but all
* other methods are supported by the map and its views. When given a key that
* doesn't satisfy the predicate, the map's {@code put()} and {@code putAll()}
* methods throw an {@link IllegalArgumentException}.
*
* <p>When methods such as {@code removeAll()} and {@code clear()} are called
* on the filtered map or its views, only mappings whose keys satisfy the
* filter will be removed from the underlying map.
*
* <p>The returned map isn't threadsafe or serializable, even if {@code
* unfiltered} is.
*
* <p>Many of the filtered map's methods, such as {@code size()},
* iterate across every key/value mapping in the underlying map and determine
* which satisfy the filter. When a live view is <i>not</i> needed, it may be
* faster to copy the filtered map and use the copy.
*
* <p><b>Warning:</b> {@code keyPredicate} must be <i>consistent with
* equals</i>, as documented at {@link Predicate#apply}. Do not provide a
* predicate such as {@code Predicates.instanceOf(ArrayList.class)}, which is
* inconsistent with equals.
*/
public static <K, V> Map<K, V> filterKeys(
Map<K, V> unfiltered, final Predicate<? super K> keyPredicate) {
if (unfiltered instanceof SortedMap) {
return filterKeys((SortedMap<K, V>) unfiltered, keyPredicate);
}
checkNotNull(keyPredicate);
Predicate<Entry<K, V>> entryPredicate =
new Predicate<Entry<K, V>>() {
@Override
public boolean apply(Entry<K, V> input) {
return keyPredicate.apply(input.getKey());
}
};
return (unfiltered instanceof AbstractFilteredMap)
? filterFiltered((AbstractFilteredMap<K, V>) unfiltered, entryPredicate)
: new FilteredKeyMap<K, V>(
checkNotNull(unfiltered), keyPredicate, entryPredicate);
}
/**
* Returns a sorted map containing the mappings in {@code unfiltered} whose
* keys satisfy a predicate. The returned map is a live view of {@code
* unfiltered}; changes to one affect the other.
*
* <p>The resulting map's {@code keySet()}, {@code entrySet()}, and {@code
* values()} views have iterators that don't support {@code remove()}, but all
* other methods are supported by the map and its views. When given a key that
* doesn't satisfy the predicate, the map's {@code put()} and {@code putAll()}
* methods throw an {@link IllegalArgumentException}.
*
* <p>When methods such as {@code removeAll()} and {@code clear()} are called
* on the filtered map or its views, only mappings whose keys satisfy the
* filter will be removed from the underlying map.
*
* <p>The returned map isn't threadsafe or serializable, even if {@code
* unfiltered} is.
*
* <p>Many of the filtered map's methods, such as {@code size()},
* iterate across every key/value mapping in the underlying map and determine
* which satisfy the filter. When a live view is <i>not</i> needed, it may be
* faster to copy the filtered map and use the copy.
*
* <p><b>Warning:</b> {@code keyPredicate} must be <i>consistent with
* equals</i>, as documented at {@link Predicate#apply}. Do not provide a
* predicate such as {@code Predicates.instanceOf(ArrayList.class)}, which is
* inconsistent with equals.
*
* @since 11.0
*/
@Beta
public static <K, V> SortedMap<K, V> filterKeys(
SortedMap<K, V> unfiltered, final Predicate<? super K> keyPredicate) {
// TODO: Return a subclass of Maps.FilteredKeyMap for slightly better
// performance.
checkNotNull(keyPredicate);
Predicate<Entry<K, V>> entryPredicate = new Predicate<Entry<K, V>>() {
@Override
public boolean apply(Entry<K, V> input) {
return keyPredicate.apply(input.getKey());
}
};
return filterEntries(unfiltered, entryPredicate);
}
/**
* Returns a map containing the mappings in {@code unfiltered} whose values
* satisfy a predicate. The returned map is a live view of {@code unfiltered};
* changes to one affect the other.
*
* <p>The resulting map's {@code keySet()}, {@code entrySet()}, and {@code
* values()} views have iterators that don't support {@code remove()}, but all
* other methods are supported by the map and its views. When given a value
* that doesn't satisfy the predicate, the map's {@code put()}, {@code
* putAll()}, and {@link Entry#setValue} methods throw an {@link
* IllegalArgumentException}.
*
* <p>When methods such as {@code removeAll()} and {@code clear()} are called
* on the filtered map or its views, only mappings whose values satisfy the
* filter will be removed from the underlying map.
*
* <p>The returned map isn't threadsafe or serializable, even if {@code
* unfiltered} is.
*
* <p>Many of the filtered map's methods, such as {@code size()},
* iterate across every key/value mapping in the underlying map and determine
* which satisfy the filter. When a live view is <i>not</i> needed, it may be
* faster to copy the filtered map and use the copy.
*
* <p><b>Warning:</b> {@code valuePredicate} must be <i>consistent with
* equals</i>, as documented at {@link Predicate#apply}. Do not provide a
* predicate such as {@code Predicates.instanceOf(ArrayList.class)}, which is
* inconsistent with equals.
*/
public static <K, V> Map<K, V> filterValues(
Map<K, V> unfiltered, final Predicate<? super V> valuePredicate) {
if (unfiltered instanceof SortedMap) {
return filterValues((SortedMap<K, V>) unfiltered, valuePredicate);
}
checkNotNull(valuePredicate);
Predicate<Entry<K, V>> entryPredicate =
new Predicate<Entry<K, V>>() {
@Override
public boolean apply(Entry<K, V> input) {
return valuePredicate.apply(input.getValue());
}
};
return filterEntries(unfiltered, entryPredicate);
}
/**
* Returns a sorted map containing the mappings in {@code unfiltered} whose
* values satisfy a predicate. The returned map is a live view of {@code
* unfiltered}; changes to one affect the other.
*
* <p>The resulting map's {@code keySet()}, {@code entrySet()}, and {@code
* values()} views have iterators that don't support {@code remove()}, but all
* other methods are supported by the map and its views. When given a value
* that doesn't satisfy the predicate, the map's {@code put()}, {@code
* putAll()}, and {@link Entry#setValue} methods throw an {@link
* IllegalArgumentException}.
*
* <p>When methods such as {@code removeAll()} and {@code clear()} are called
* on the filtered map or its views, only mappings whose values satisfy the
* filter will be removed from the underlying map.
*
* <p>The returned map isn't threadsafe or serializable, even if {@code
* unfiltered} is.
*
* <p>Many of the filtered map's methods, such as {@code size()},
* iterate across every key/value mapping in the underlying map and determine
* which satisfy the filter. When a live view is <i>not</i> needed, it may be
* faster to copy the filtered map and use the copy.
*
* <p><b>Warning:</b> {@code valuePredicate} must be <i>consistent with
* equals</i>, as documented at {@link Predicate#apply}. Do not provide a
* predicate such as {@code Predicates.instanceOf(ArrayList.class)}, which is
* inconsistent with equals.
*
* @since 11.0
*/
@Beta
public static <K, V> SortedMap<K, V> filterValues(
SortedMap<K, V> unfiltered, final Predicate<? super V> valuePredicate) {
checkNotNull(valuePredicate);
Predicate<Entry<K, V>> entryPredicate =
new Predicate<Entry<K, V>>() {
@Override
public boolean apply(Entry<K, V> input) {
return valuePredicate.apply(input.getValue());
}
};
return filterEntries(unfiltered, entryPredicate);
}
/**
* Returns a map containing the mappings in {@code unfiltered} that satisfy a
* predicate. The returned map is a live view of {@code unfiltered}; changes
* to one affect the other.
*
* <p>The resulting map's {@code keySet()}, {@code entrySet()}, and {@code
* values()} views have iterators that don't support {@code remove()}, but all
* other methods are supported by the map and its views. When given a
* key/value pair that doesn't satisfy the predicate, the map's {@code put()}
* and {@code putAll()} methods throw an {@link IllegalArgumentException}.
* Similarly, the map's entries have a {@link Entry#setValue} method that
* throws an {@link IllegalArgumentException} when the existing key and the
* provided value don't satisfy the predicate.
*
* <p>When methods such as {@code removeAll()} and {@code clear()} are called
* on the filtered map or its views, only mappings that satisfy the filter
* will be removed from the underlying map.
*
* <p>The returned map isn't threadsafe or serializable, even if {@code
* unfiltered} is.
*
* <p>Many of the filtered map's methods, such as {@code size()},
* iterate across every key/value mapping in the underlying map and determine
* which satisfy the filter. When a live view is <i>not</i> needed, it may be
* faster to copy the filtered map and use the copy.
*
* <p><b>Warning:</b> {@code entryPredicate} must be <i>consistent with
* equals</i>, as documented at {@link Predicate#apply}.
*/
public static <K, V> Map<K, V> filterEntries(
Map<K, V> unfiltered, Predicate<? super Entry<K, V>> entryPredicate) {
if (unfiltered instanceof SortedMap) {
return filterEntries((SortedMap<K, V>) unfiltered, entryPredicate);
}
checkNotNull(entryPredicate);
return (unfiltered instanceof AbstractFilteredMap)
? filterFiltered((AbstractFilteredMap<K, V>) unfiltered, entryPredicate)
: new FilteredEntryMap<K, V>(checkNotNull(unfiltered), entryPredicate);
}
/**
* Returns a sorted map containing the mappings in {@code unfiltered} that
* satisfy a predicate. The returned map is a live view of {@code unfiltered};
* changes to one affect the other.
*
* <p>The resulting map's {@code keySet()}, {@code entrySet()}, and {@code
* values()} views have iterators that don't support {@code remove()}, but all
* other methods are supported by the map and its views. When given a
* key/value pair that doesn't satisfy the predicate, the map's {@code put()}
* and {@code putAll()} methods throw an {@link IllegalArgumentException}.
* Similarly, the map's entries have a {@link Entry#setValue} method that
* throws an {@link IllegalArgumentException} when the existing key and the
* provided value don't satisfy the predicate.
*
* <p>When methods such as {@code removeAll()} and {@code clear()} are called
* on the filtered map or its views, only mappings that satisfy the filter
* will be removed from the underlying map.
*
* <p>The returned map isn't threadsafe or serializable, even if {@code
* unfiltered} is.
*
* <p>Many of the filtered map's methods, such as {@code size()},
* iterate across every key/value mapping in the underlying map and determine
* which satisfy the filter. When a live view is <i>not</i> needed, it may be
* faster to copy the filtered map and use the copy.
*
* <p><b>Warning:</b> {@code entryPredicate} must be <i>consistent with
* equals</i>, as documented at {@link Predicate#apply}.
*
* @since 11.0
*/
@Beta
public static <K, V> SortedMap<K, V> filterEntries(
SortedMap<K, V> unfiltered,
Predicate<? super Entry<K, V>> entryPredicate) {
checkNotNull(entryPredicate);
return (unfiltered instanceof FilteredEntrySortedMap)
? filterFiltered((FilteredEntrySortedMap<K, V>) unfiltered, entryPredicate)
: new FilteredEntrySortedMap<K, V>(checkNotNull(unfiltered), entryPredicate);
}
/**
* Support {@code clear()}, {@code removeAll()}, and {@code retainAll()} when
* filtering a filtered map.
*/
private static <K, V> Map<K, V> filterFiltered(AbstractFilteredMap<K, V> map,
Predicate<? super Entry<K, V>> entryPredicate) {
Predicate<Entry<K, V>> predicate =
Predicates.and(map.predicate, entryPredicate);
return new FilteredEntryMap<K, V>(map.unfiltered, predicate);
}
private abstract static class AbstractFilteredMap<K, V>
extends AbstractMap<K, V> {
final Map<K, V> unfiltered;
final Predicate<? super Entry<K, V>> predicate;
AbstractFilteredMap(
Map<K, V> unfiltered, Predicate<? super Entry<K, V>> predicate) {
this.unfiltered = unfiltered;
this.predicate = predicate;
}
boolean apply(Object key, V value) {
// This method is called only when the key is in the map, implying that
// key is a K.
@SuppressWarnings("unchecked")
K k = (K) key;
return predicate.apply(Maps.immutableEntry(k, value));
}
@Override public V put(K key, V value) {
checkArgument(apply(key, value));
return unfiltered.put(key, value);
}
@Override public void putAll(Map<? extends K, ? extends V> map) {
for (Entry<? extends K, ? extends V> entry : map.entrySet()) {
checkArgument(apply(entry.getKey(), entry.getValue()));
}
unfiltered.putAll(map);
}
@Override public boolean containsKey(Object key) {
return unfiltered.containsKey(key) && apply(key, unfiltered.get(key));
}
@Override public V get(Object key) {
V value = unfiltered.get(key);
return ((value != null) && apply(key, value)) ? value : null;
}
@Override public boolean isEmpty() {
return entrySet().isEmpty();
}
@Override public V remove(Object key) {
return containsKey(key) ? unfiltered.remove(key) : null;
}
Collection<V> values;
@Override public Collection<V> values() {
Collection<V> result = values;
return (result == null) ? values = new Values() : result;
}
class Values extends AbstractCollection<V> {
@Override public Iterator<V> iterator() {
final Iterator<Entry<K, V>> entryIterator = entrySet().iterator();
return new UnmodifiableIterator<V>() {
@Override
public boolean hasNext() {
return entryIterator.hasNext();
}
@Override
public V next() {
return entryIterator.next().getValue();
}
};
}
@Override public int size() {
return entrySet().size();
}
@Override public void clear() {
entrySet().clear();
}
@Override public boolean isEmpty() {
return entrySet().isEmpty();
}
@Override public boolean remove(Object o) {
Iterator<Entry<K, V>> iterator = unfiltered.entrySet().iterator();
while (iterator.hasNext()) {
Entry<K, V> entry = iterator.next();
if (Objects.equal(o, entry.getValue()) && predicate.apply(entry)) {
iterator.remove();
return true;
}
}
return false;
}
@Override public boolean removeAll(Collection<?> collection) {
checkNotNull(collection);
boolean changed = false;
Iterator<Entry<K, V>> iterator = unfiltered.entrySet().iterator();
while (iterator.hasNext()) {
Entry<K, V> entry = iterator.next();
if (collection.contains(entry.getValue()) && predicate.apply(entry)) {
iterator.remove();
changed = true;
}
}
return changed;
}
@Override public boolean retainAll(Collection<?> collection) {
checkNotNull(collection);
boolean changed = false;
Iterator<Entry<K, V>> iterator = unfiltered.entrySet().iterator();
while (iterator.hasNext()) {
Entry<K, V> entry = iterator.next();
if (!collection.contains(entry.getValue())
&& predicate.apply(entry)) {
iterator.remove();
changed = true;
}
}
return changed;
}
@Override public Object[] toArray() {
// creating an ArrayList so filtering happens once
return Lists.newArrayList(iterator()).toArray();
}
@Override public <T> T[] toArray(T[] array) {
return Lists.newArrayList(iterator()).toArray(array);
}
}
}
/**
* Support {@code clear()}, {@code removeAll()}, and {@code retainAll()} when
* filtering a filtered sorted map.
*/
private static <K, V> SortedMap<K, V> filterFiltered(
FilteredEntrySortedMap<K, V> map,
Predicate<? super Entry<K, V>> entryPredicate) {
Predicate<Entry<K, V>> predicate
= Predicates.and(map.predicate, entryPredicate);
return new FilteredEntrySortedMap<K, V>(map.sortedMap(), predicate);
}
private static class FilteredEntrySortedMap<K, V>
extends FilteredEntryMap<K, V> implements SortedMap<K, V> {
FilteredEntrySortedMap(SortedMap<K, V> unfiltered,
Predicate<? super Entry<K, V>> entryPredicate) {
super(unfiltered, entryPredicate);
}
SortedMap<K, V> sortedMap() {
return (SortedMap<K, V>) unfiltered;
}
@Override public Comparator<? super K> comparator() {
return sortedMap().comparator();
}
@Override public K firstKey() {
// correctly throws NoSuchElementException when filtered map is empty.
return keySet().iterator().next();
}
@Override public K lastKey() {
SortedMap<K, V> headMap = sortedMap();
while (true) {
// correctly throws NoSuchElementException when filtered map is empty.
K key = headMap.lastKey();
if (apply(key, unfiltered.get(key))) {
return key;
}
headMap = sortedMap().headMap(key);
}
}
@Override public SortedMap<K, V> headMap(K toKey) {
return new FilteredEntrySortedMap<K, V>(sortedMap().headMap(toKey), predicate);
}
@Override public SortedMap<K, V> subMap(K fromKey, K toKey) {
return new FilteredEntrySortedMap<K, V>(
sortedMap().subMap(fromKey, toKey), predicate);
}
@Override public SortedMap<K, V> tailMap(K fromKey) {
return new FilteredEntrySortedMap<K, V>(
sortedMap().tailMap(fromKey), predicate);
}
}
private static class FilteredKeyMap<K, V> extends AbstractFilteredMap<K, V> {
Predicate<? super K> keyPredicate;
FilteredKeyMap(Map<K, V> unfiltered, Predicate<? super K> keyPredicate,
Predicate<Entry<K, V>> entryPredicate) {
super(unfiltered, entryPredicate);
this.keyPredicate = keyPredicate;
}
Set<Entry<K, V>> entrySet;
@Override public Set<Entry<K, V>> entrySet() {
Set<Entry<K, V>> result = entrySet;
return (result == null)
? entrySet = Sets.filter(unfiltered.entrySet(), predicate)
: result;
}
Set<K> keySet;
@Override public Set<K> keySet() {
Set<K> result = keySet;
return (result == null)
? keySet = Sets.filter(unfiltered.keySet(), keyPredicate)
: result;
}
// The cast is called only when the key is in the unfiltered map, implying
// that key is a K.
@Override
@SuppressWarnings("unchecked")
public boolean containsKey(Object key) {
return unfiltered.containsKey(key) && keyPredicate.apply((K) key);
}
}
static class FilteredEntryMap<K, V> extends AbstractFilteredMap<K, V> {
/**
* Entries in this set satisfy the predicate, but they don't validate the
* input to {@code Entry.setValue()}.
*/
final Set<Entry<K, V>> filteredEntrySet;
FilteredEntryMap(
Map<K, V> unfiltered, Predicate<? super Entry<K, V>> entryPredicate) {
super(unfiltered, entryPredicate);
filteredEntrySet = Sets.filter(unfiltered.entrySet(), predicate);
}
Set<Entry<K, V>> entrySet;
@Override public Set<Entry<K, V>> entrySet() {
Set<Entry<K, V>> result = entrySet;
return (result == null) ? entrySet = new EntrySet() : result;
}
private class EntrySet extends ForwardingSet<Entry<K, V>> {
@Override protected Set<Entry<K, V>> delegate() {
return filteredEntrySet;
}
@Override public Iterator<Entry<K, V>> iterator() {
final Iterator<Entry<K, V>> iterator = filteredEntrySet.iterator();
return new UnmodifiableIterator<Entry<K, V>>() {
@Override
public boolean hasNext() {
return iterator.hasNext();
}
@Override
public Entry<K, V> next() {
final Entry<K, V> entry = iterator.next();
return new ForwardingMapEntry<K, V>() {
@Override protected Entry<K, V> delegate() {
return entry;
}
@Override public V setValue(V value) {
checkArgument(apply(entry.getKey(), value));
return super.setValue(value);
}
};
}
};
}
}
Set<K> keySet;
@Override public Set<K> keySet() {
Set<K> result = keySet;
return (result == null) ? keySet = new KeySet() : result;
}
private class KeySet extends AbstractSet<K> {
@Override public Iterator<K> iterator() {
final Iterator<Entry<K, V>> iterator = filteredEntrySet.iterator();
return new UnmodifiableIterator<K>() {
@Override
public boolean hasNext() {
return iterator.hasNext();
}
@Override
public K next() {
return iterator.next().getKey();
}
};
}
@Override public int size() {
return filteredEntrySet.size();
}
@Override public void clear() {
filteredEntrySet.clear();
}
@Override public boolean contains(Object o) {
return containsKey(o);
}
@Override public boolean remove(Object o) {
if (containsKey(o)) {
unfiltered.remove(o);
return true;
}
return false;
}
@Override public boolean removeAll(Collection<?> collection) {
checkNotNull(collection); // for GWT
boolean changed = false;
for (Object obj : collection) {
changed |= remove(obj);
}
return changed;
}
@Override public boolean retainAll(Collection<?> collection) {
checkNotNull(collection); // for GWT
boolean changed = false;
Iterator<Entry<K, V>> iterator = unfiltered.entrySet().iterator();
while (iterator.hasNext()) {
Entry<K, V> entry = iterator.next();
if (!collection.contains(entry.getKey()) && predicate.apply(entry)) {
iterator.remove();
changed = true;
}
}
return changed;
}
@Override public Object[] toArray() {
// creating an ArrayList so filtering happens once
return Lists.newArrayList(iterator()).toArray();
}
@Override public <T> T[] toArray(T[] array) {
return Lists.newArrayList(iterator()).toArray(array);
}
}
}
@Nullable private static <K, V> Entry<K, V> unmodifiableOrNull(@Nullable Entry<K, V> entry) {
return (entry == null) ? null : Maps.unmodifiableEntry(entry);
}
/**
* {@code AbstractMap} extension that implements {@link #isEmpty()} as {@code
* entrySet().isEmpty()} instead of {@code size() == 0} to speed up
* implementations where {@code size()} is O(n), and it delegates the {@code
* isEmpty()} methods of its key set and value collection to this
* implementation.
*/
@GwtCompatible
static abstract class ImprovedAbstractMap<K, V> extends AbstractMap<K, V> {
/**
* Creates the entry set to be returned by {@link #entrySet()}. This method
* is invoked at most once on a given map, at the time when {@code entrySet}
* is first called.
*/
protected abstract Set<Entry<K, V>> createEntrySet();
private Set<Entry<K, V>> entrySet;
@Override public Set<Entry<K, V>> entrySet() {
Set<Entry<K, V>> result = entrySet;
if (result == null) {
entrySet = result = createEntrySet();
}
return result;
}
private Set<K> keySet;
@Override public Set<K> keySet() {
Set<K> result = keySet;
if (result == null) {
return keySet = new KeySet<K, V>() {
@Override Map<K, V> map() {
return ImprovedAbstractMap.this;
}
};
}
return result;
}
private Collection<V> values;
@Override public Collection<V> values() {
Collection<V> result = values;
if (result == null) {
return values = new Values<K, V>(){
@Override Map<K, V> map() {
return ImprovedAbstractMap.this;
}
};
}
return result;
}
/**
* Returns {@code true} if this map contains no key-value mappings.
*
* <p>The implementation returns {@code entrySet().isEmpty()}.
*
* @return {@code true} if this map contains no key-value mappings
*/
@Override public boolean isEmpty() {
return entrySet().isEmpty();
}
}
static final MapJoiner STANDARD_JOINER =
Collections2.STANDARD_JOINER.withKeyValueSeparator("=");
/**
* Delegates to {@link Map#get}. Returns {@code null} on {@code
* ClassCastException}.
*/
static <V> V safeGet(Map<?, V> map, Object key) {
try {
return map.get(key);
} catch (ClassCastException e) {
return null;
}
}
/**
* Delegates to {@link Map#containsKey}. Returns {@code false} on {@code
* ClassCastException}
*/
static boolean safeContainsKey(Map<?, ?> map, Object key) {
try {
return map.containsKey(key);
} catch (ClassCastException e) {
return false;
}
}
/**
* Implements {@code Collection.contains} safely for forwarding collections of
* map entries. If {@code o} is an instance of {@code Map.Entry}, it is
* wrapped using {@link #unmodifiableEntry} to protect against a possible
* nefarious equals method.
*
* <p>Note that {@code c} is the backing (delegate) collection, rather than
* the forwarding collection.
*
* @param c the delegate (unwrapped) collection of map entries
* @param o the object that might be contained in {@code c}
* @return {@code true} if {@code c} contains {@code o}
*/
static <K, V> boolean containsEntryImpl(Collection<Entry<K, V>> c, Object o) {
if (!(o instanceof Entry)) {
return false;
}
return c.contains(unmodifiableEntry((Entry<?, ?>) o));
}
/**
* Implements {@code Collection.remove} safely for forwarding collections of
* map entries. If {@code o} is an instance of {@code Map.Entry}, it is
* wrapped using {@link #unmodifiableEntry} to protect against a possible
* nefarious equals method.
*
* <p>Note that {@code c} is backing (delegate) collection, rather than the
* forwarding collection.
*
* @param c the delegate (unwrapped) collection of map entries
* @param o the object to remove from {@code c}
* @return {@code true} if {@code c} was changed
*/
static <K, V> boolean removeEntryImpl(Collection<Entry<K, V>> c, Object o) {
if (!(o instanceof Entry)) {
return false;
}
return c.remove(unmodifiableEntry((Entry<?, ?>) o));
}
/**
* An implementation of {@link Map#equals}.
*/
static boolean equalsImpl(Map<?, ?> map, Object object) {
if (map == object) {
return true;
}
if (object instanceof Map) {
Map<?, ?> o = (Map<?, ?>) object;
return map.entrySet().equals(o.entrySet());
}
return false;
}
/**
* An implementation of {@link Map#hashCode}.
*/
static int hashCodeImpl(Map<?, ?> map) {
return Sets.hashCodeImpl(map.entrySet());
}
/**
* An implementation of {@link Map#toString}.
*/
static String toStringImpl(Map<?, ?> map) {
StringBuilder sb
= Collections2.newStringBuilderForCollection(map.size()).append('{');
STANDARD_JOINER.appendTo(sb, map);
return sb.append('}').toString();
}
/**
* An implementation of {@link Map#putAll}.
*/
static <K, V> void putAllImpl(
Map<K, V> self, Map<? extends K, ? extends V> map) {
for (Map.Entry<? extends K, ? extends V> entry : map.entrySet()) {
self.put(entry.getKey(), entry.getValue());
}
}
/**
* An admittedly inefficient implementation of {@link Map#containsKey}.
*/
static boolean containsKeyImpl(Map<?, ?> map, @Nullable Object key) {
for (Entry<?, ?> entry : map.entrySet()) {
if (Objects.equal(entry.getKey(), key)) {
return true;
}
}
return false;
}
/**
* An implementation of {@link Map#containsValue}.
*/
static boolean containsValueImpl(Map<?, ?> map, @Nullable Object value) {
for (Entry<?, ?> entry : map.entrySet()) {
if (Objects.equal(entry.getValue(), value)) {
return true;
}
}
return false;
}
abstract static class KeySet<K, V> extends AbstractSet<K> {
abstract Map<K, V> map();
@Override public Iterator<K> iterator() {
return Iterators.transform(map().entrySet().iterator(),
new Function<Map.Entry<K, V>, K>() {
@Override public K apply(Entry<K, V> entry) {
return entry.getKey();
}
});
}
@Override public int size() {
return map().size();
}
@Override public boolean isEmpty() {
return map().isEmpty();
}
@Override public boolean contains(Object o) {
return map().containsKey(o);
}
@Override public boolean remove(Object o) {
if (contains(o)) {
map().remove(o);
return true;
}
return false;
}
@Override
public boolean removeAll(Collection<?> c) {
// TODO(user): find out why this is necessary to make GWT tests pass.
return super.removeAll(checkNotNull(c));
}
@Override public void clear() {
map().clear();
}
}
@Nullable
static <K> K keyOrNull(@Nullable Entry<K, ?> entry) {
return (entry == null) ? null : entry.getKey();
}
abstract static class Values<K, V> extends AbstractCollection<V> {
abstract Map<K, V> map();
@Override public Iterator<V> iterator() {
return Iterators.transform(map().entrySet().iterator(),
new Function<Entry<K, V>, V>() {
@Override public V apply(Entry<K, V> entry) {
return entry.getValue();
}
});
}
@Override public boolean remove(Object o) {
try {
return super.remove(o);
} catch (UnsupportedOperationException e) {
for (Entry<K, V> entry : map().entrySet()) {
if (Objects.equal(o, entry.getValue())) {
map().remove(entry.getKey());
return true;
}
}
return false;
}
}
@Override public boolean removeAll(Collection<?> c) {
try {
return super.removeAll(checkNotNull(c));
} catch (UnsupportedOperationException e) {
Set<K> toRemove = Sets.newHashSet();
for (Entry<K, V> entry : map().entrySet()) {
if (c.contains(entry.getValue())) {
toRemove.add(entry.getKey());
}
}
return map().keySet().removeAll(toRemove);
}
}
@Override public boolean retainAll(Collection<?> c) {
try {
return super.retainAll(checkNotNull(c));
} catch (UnsupportedOperationException e) {
Set<K> toRetain = Sets.newHashSet();
for (Entry<K, V> entry : map().entrySet()) {
if (c.contains(entry.getValue())) {
toRetain.add(entry.getKey());
}
}
return map().keySet().retainAll(toRetain);
}
}
@Override public int size() {
return map().size();
}
@Override public boolean isEmpty() {
return map().isEmpty();
}
@Override public boolean contains(@Nullable Object o) {
return map().containsValue(o);
}
@Override public void clear() {
map().clear();
}
}
abstract static class EntrySet<K, V> extends AbstractSet<Entry<K, V>> {
abstract Map<K, V> map();
@Override public int size() {
return map().size();
}
@Override public void clear() {
map().clear();
}
@Override public boolean contains(Object o) {
if (o instanceof Entry) {
Entry<?, ?> entry = (Entry<?, ?>) o;
Object key = entry.getKey();
V value = map().get(key);
return Objects.equal(value, entry.getValue())
&& (value != null || map().containsKey(key));
}
return false;
}
@Override public boolean isEmpty() {
return map().isEmpty();
}
@Override public boolean remove(Object o) {
if (contains(o)) {
Entry<?, ?> entry = (Entry<?, ?>) o;
return map().keySet().remove(entry.getKey());
}
return false;
}
@Override public boolean removeAll(Collection<?> c) {
try {
return super.removeAll(checkNotNull(c));
} catch (UnsupportedOperationException e) {
// if the iterators don't support remove
boolean changed = true;
for (Object o : c) {
changed |= remove(o);
}
return changed;
}
}
@Override public boolean retainAll(Collection<?> c) {
try {
return super.retainAll(checkNotNull(c));
} catch (UnsupportedOperationException e) {
// if the iterators don't support remove
Set<Object> keys = Sets.newHashSetWithExpectedSize(c.size());
for (Object o : c) {
if (contains(o)) {
Entry<?, ?> entry = (Entry<?, ?>) o;
keys.add(entry.getKey());
}
}
return map().keySet().retainAll(keys);
}
}
}
}
| Java |
/*
* Copyright (C) 2007 The Guava Authors
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package com.google.common.collect;
import com.google.common.annotations.GwtCompatible;
import java.util.Collection;
import javax.annotation.Nullable;
/**
* Static utility methods pertaining to object arrays.
*
* @author Kevin Bourrillion
* @since 2.0 (imported from Google Collections Library)
*/
@GwtCompatible(emulated = true)
public final class ObjectArrays {
private ObjectArrays() {}
/**
* Returns a new array of the given length with the same type as a reference
* array.
*
* @param reference any array of the desired type
* @param length the length of the new array
*/
public static <T> T[] newArray(T[] reference, int length) {
return Platform.newArray(reference, length);
}
/**
* Returns a new array that prepends {@code element} to {@code array}.
*
* @param element the element to prepend to the front of {@code array}
* @param array the array of elements to append
* @return an array whose size is one larger than {@code array}, with
* {@code element} occupying the first position, and the
* elements of {@code array} occupying the remaining elements.
*/
public static <T> T[] concat(@Nullable T element, T[] array) {
T[] result = newArray(array, array.length + 1);
result[0] = element;
Platform.unsafeArrayCopy(array, 0, result, 1, array.length);
return result;
}
/**
* Returns a new array that appends {@code element} to {@code array}.
*
* @param array the array of elements to prepend
* @param element the element to append to the end
* @return an array whose size is one larger than {@code array}, with
* the same contents as {@code array}, plus {@code element} occupying the
* last position.
*/
public static <T> T[] concat(T[] array, @Nullable T element) {
T[] result = arraysCopyOf(array, array.length + 1);
result[array.length] = element;
return result;
}
/** GWT safe version of Arrays.copyOf. */
static <T> T[] arraysCopyOf(T[] original, int newLength) {
T[] copy = newArray(original, newLength);
Platform.unsafeArrayCopy(
original, 0, copy, 0, Math.min(original.length, newLength));
return copy;
}
/**
* Returns an array containing all of the elements in the specified
* collection; the runtime type of the returned array is that of the specified
* array. If the collection fits in the specified array, it is returned
* therein. Otherwise, a new array is allocated with the runtime type of the
* specified array and the size of the specified collection.
*
* <p>If the collection fits in the specified array with room to spare (i.e.,
* the array has more elements than the collection), the element in the array
* immediately following the end of the collection is set to {@code null}.
* This is useful in determining the length of the collection <i>only</i> if
* the caller knows that the collection does not contain any null elements.
*
* <p>This method returns the elements in the order they are returned by the
* collection's iterator.
*
* <p>TODO(kevinb): support concurrently modified collections?
*
* @param c the collection for which to return an array of elements
* @param array the array in which to place the collection elements
* @throws ArrayStoreException if the runtime type of the specified array is
* not a supertype of the runtime type of every element in the specified
* collection
*/
static <T> T[] toArrayImpl(Collection<?> c, T[] array) {
int size = c.size();
if (array.length < size) {
array = newArray(array, size);
}
fillArray(c, array);
if (array.length > size) {
array[size] = null;
}
return array;
}
/**
* Returns an array containing all of the elements in the specified
* collection. This method returns the elements in the order they are returned
* by the collection's iterator. The returned array is "safe" in that no
* references to it are maintained by the collection. The caller is thus free
* to modify the returned array.
*
* <p>This method assumes that the collection size doesn't change while the
* method is running.
*
* <p>TODO(kevinb): support concurrently modified collections?
*
* @param c the collection for which to return an array of elements
*/
static Object[] toArrayImpl(Collection<?> c) {
return fillArray(c, new Object[c.size()]);
}
private static Object[] fillArray(Iterable<?> elements, Object[] array) {
int i = 0;
for (Object element : elements) {
array[i++] = element;
}
return array;
}
/**
* Swaps {@code array[i]} with {@code array[j]}.
*/
static void swap(Object[] array, int i, int j) {
Object temp = array[i];
array[i] = array[j];
array[j] = temp;
}
}
| Java |
/*
* Copyright (C) 2009 The Guava Authors
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package com.google.common.collect;
import static com.google.common.base.Preconditions.checkNotNull;
import com.google.common.collect.Lists;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Collection;
import java.util.Collections;
import java.util.Iterator;
import java.util.List;
import java.util.ListIterator;
import java.util.RandomAccess;
import javax.annotation.Nullable;
/**
* GWT emulated version of {@link ImmutableList}.
*
* @author Hayward Chan
*/
@SuppressWarnings("serial") // we're overriding default serialization
public abstract class ImmutableList<E> extends ForwardingImmutableCollection<E>
implements List<E>, RandomAccess {
private transient final List<E> delegate;
ImmutableList(List<E> delegate) {
super(delegate);
this.delegate = Collections.unmodifiableList(delegate);
}
ImmutableList() {
this(Collections.<E>emptyList());
}
// Casting to any type is safe because the list will never hold any elements.
@SuppressWarnings("unchecked")
public static <E> ImmutableList<E> of() {
return (ImmutableList<E>) EmptyImmutableList.INSTANCE;
}
public static <E> ImmutableList<E> of(E element) {
return new SingletonImmutableList<E>(element);
}
public static <E> ImmutableList<E> of(E e1, E e2) {
return new RegularImmutableList<E>(
ImmutableList.<E>nullCheckedList(e1, e2));
}
public static <E> ImmutableList<E> of(E e1, E e2, E e3) {
return new RegularImmutableList<E>(
ImmutableList.<E>nullCheckedList(e1, e2, e3));
}
public static <E> ImmutableList<E> of(E e1, E e2, E e3, E e4) {
return new RegularImmutableList<E>(
ImmutableList.<E>nullCheckedList(e1, e2, e3, e4));
}
public static <E> ImmutableList<E> of(E e1, E e2, E e3, E e4, E e5) {
return new RegularImmutableList<E>(
ImmutableList.<E>nullCheckedList(e1, e2, e3, e4, e5));
}
public static <E> ImmutableList<E> of(E e1, E e2, E e3, E e4, E e5, E e6) {
return new RegularImmutableList<E>(
ImmutableList.<E>nullCheckedList(e1, e2, e3, e4, e5, e6));
}
public static <E> ImmutableList<E> of(
E e1, E e2, E e3, E e4, E e5, E e6, E e7) {
return new RegularImmutableList<E>(
ImmutableList.<E>nullCheckedList(e1, e2, e3, e4, e5, e6, e7));
}
public static <E> ImmutableList<E> of(
E e1, E e2, E e3, E e4, E e5, E e6, E e7, E e8) {
return new RegularImmutableList<E>(
ImmutableList.<E>nullCheckedList(e1, e2, e3, e4, e5, e6, e7, e8));
}
public static <E> ImmutableList<E> of(
E e1, E e2, E e3, E e4, E e5, E e6, E e7, E e8, E e9) {
return new RegularImmutableList<E>(
ImmutableList.<E>nullCheckedList(e1, e2, e3, e4, e5, e6, e7, e8, e9));
}
public static <E> ImmutableList<E> of(
E e1, E e2, E e3, E e4, E e5, E e6, E e7, E e8, E e9, E e10) {
return new RegularImmutableList<E>(ImmutableList.<E>nullCheckedList(
e1, e2, e3, e4, e5, e6, e7, e8, e9, e10));
}
public static <E> ImmutableList<E> of(
E e1, E e2, E e3, E e4, E e5, E e6, E e7, E e8, E e9, E e10, E e11) {
return new RegularImmutableList<E>(ImmutableList.<E>nullCheckedList(
e1, e2, e3, e4, e5, e6, e7, e8, e9, e10, e11));
}
public static <E> ImmutableList<E> of(
E e1, E e2, E e3, E e4, E e5, E e6, E e7, E e8, E e9, E e10, E e11,
E e12, E... others) {
final int paramCount = 12;
Object[] array = new Object[paramCount + others.length];
arrayCopy(array, 0, e1, e2, e3, e4, e5, e6, e7, e8, e9, e10, e11, e12);
arrayCopy(array, paramCount, others);
return new RegularImmutableList<E>(ImmutableList.<E>nullCheckedList(array));
}
public static <E> ImmutableList<E> of(E[] elements) {
checkNotNull(elements); // for GWT
switch (elements.length) {
case 0:
return ImmutableList.of();
case 1:
return new SingletonImmutableList<E>(elements[0]);
default:
return new RegularImmutableList<E>(
ImmutableList.<E>nullCheckedList(elements));
}
}
private static void arrayCopy(Object[] dest, int pos, Object... source) {
System.arraycopy(source, 0, dest, pos, source.length);
}
public static <E> ImmutableList<E> copyOf(Iterable<? extends E> elements) {
checkNotNull(elements); // for GWT
return (elements instanceof Collection)
? copyOf((Collection<? extends E>) elements)
: copyOf(elements.iterator());
}
public static <E> ImmutableList<E> copyOf(Iterator<? extends E> elements) {
return copyFromCollection(Lists.newArrayList(elements));
}
public static <E> ImmutableList<E> copyOf(Collection<? extends E> elements) {
if (elements instanceof ImmutableCollection) {
/*
* TODO: When given an ImmutableList that's a sublist, copy the referenced
* portion of the array into a new array to save space?
*/
@SuppressWarnings("unchecked") // all supported methods are covariant
ImmutableCollection<E> list = (ImmutableCollection<E>) elements;
return list.asList();
}
return copyFromCollection(elements);
}
public static <E> ImmutableList<E> copyOf(E[] elements) {
checkNotNull(elements); // eager for GWT
return copyOf(Arrays.asList(elements));
}
private static <E> ImmutableList<E> copyFromCollection(
Collection<? extends E> collection) {
Object[] elements = collection.toArray();
switch (elements.length) {
case 0:
return of();
case 1:
@SuppressWarnings("unchecked") // collection had only Es in it
ImmutableList<E> list = new SingletonImmutableList<E>((E) elements[0]);
return list;
default:
return new RegularImmutableList<E>(ImmutableList.<E>nullCheckedList(elements));
}
}
// Factory method that skips the null checks. Used only when the elements
// are guaranteed to be null.
static <E> ImmutableList<E> unsafeDelegateList(List<? extends E> list) {
switch (list.size()) {
case 0:
return of();
case 1:
return new SingletonImmutableList<E>(list.iterator().next());
default:
@SuppressWarnings("unchecked")
List<E> castedList = (List<E>) list;
return new RegularImmutableList<E>(castedList);
}
}
static <E> ImmutableList<E> backedBy(E[] elements) {
return unsafeDelegateList(Arrays.asList(elements));
}
private static <E> List<E> nullCheckedList(Object... array) {
for (int i = 0, len = array.length; i < len; i++) {
if (array[i] == null) {
throw new NullPointerException("at index " + i);
}
}
@SuppressWarnings("unchecked")
E[] castedArray = (E[]) array;
return Arrays.asList(castedArray);
}
public int indexOf(@Nullable Object object) {
return delegate.indexOf(object);
}
public int lastIndexOf(@Nullable Object object) {
return delegate.lastIndexOf(object);
}
public final boolean addAll(int index, Collection<? extends E> newElements) {
throw new UnsupportedOperationException();
}
public final E set(int index, E element) {
throw new UnsupportedOperationException();
}
public final void add(int index, E element) {
throw new UnsupportedOperationException();
}
public final E remove(int index) {
throw new UnsupportedOperationException();
}
public E get(int index) {
return delegate.get(index);
}
public ImmutableList<E> subList(int fromIndex, int toIndex) {
return unsafeDelegateList(delegate.subList(fromIndex, toIndex));
}
public ListIterator<E> listIterator() {
return delegate.listIterator();
}
public ListIterator<E> listIterator(int index) {
return delegate.listIterator(index);
}
@Override public ImmutableList<E> asList() {
return this;
}
public ImmutableList<E> reverse(){
List<E> list = Lists.newArrayList(this);
Collections.reverse(list);
return unsafeDelegateList(list);
}
@Override public Object[] toArray() {
// Note that ArrayList.toArray() doesn't work here because it returns E[]
// instead of Object[].
return delegate.toArray(new Object[size()]);
}
@Override public boolean equals(Object obj) {
return delegate.equals(obj);
}
@Override public int hashCode() {
return delegate.hashCode();
}
public static <E> Builder<E> builder() {
return new Builder<E>();
}
public static final class Builder<E> extends ImmutableCollection.Builder<E> {
private final ArrayList<E> contents = Lists.newArrayList();
public Builder() {}
@Override public Builder<E> add(E element) {
contents.add(checkNotNull(element));
return this;
}
@Override public Builder<E> addAll(Iterable<? extends E> elements) {
super.addAll(elements);
return this;
}
@Override public Builder<E> add(E... elements) {
checkNotNull(elements); // for GWT
super.add(elements);
return this;
}
@Override public Builder<E> addAll(Iterator<? extends E> elements) {
super.addAll(elements);
return this;
}
@Override public ImmutableList<E> build() {
return copyOf(contents);
}
}
}
| Java |
/*
* Copyright (C) 2009 The Guava Authors
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package com.google.common.collect;
import static com.google.common.base.Preconditions.checkNotNull;
import java.util.Collections;
/**
* GWT emulated version of {@link SingletonImmutableList}.
*
* @author Hayward Chan
*/
final class SingletonImmutableList<E> extends ImmutableList<E> {
// This reference is used both by the custom field serializer, and by the
// GWT compiler to infer the elements of the lists that needs to be
// serialized.
E element;
SingletonImmutableList(E element) {
super(Collections.singletonList(checkNotNull(element)));
this.element = element;
}
}
| Java |
/*
* Copyright (C) 2007 The Guava Authors
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package com.google.common.collect;
import static com.google.common.base.Preconditions.checkArgument;
import static com.google.common.base.Preconditions.checkNotNull;
import static com.google.common.base.Preconditions.checkState;
import com.google.common.annotations.Beta;
import com.google.common.annotations.GwtCompatible;
import com.google.common.base.Function;
import com.google.common.base.Objects;
import com.google.common.base.Optional;
import com.google.common.base.Preconditions;
import com.google.common.base.Predicate;
import java.util.Arrays;
import java.util.Collection;
import java.util.Collections;
import java.util.Comparator;
import java.util.Enumeration;
import java.util.Iterator;
import java.util.List;
import java.util.NoSuchElementException;
import java.util.PriorityQueue;
import java.util.Queue;
import javax.annotation.Nullable;
/**
* This class contains static utility methods that operate on or return objects
* of type {@link Iterator}. Except as noted, each method has a corresponding
* {@link Iterable}-based method in the {@link Iterables} class.
*
* <p><i>Performance notes:</i> Unless otherwise noted, all of the iterators
* produced in this class are <i>lazy</i>, which means that they only advance
* the backing iteration when absolutely necessary.
*
* <p>See the Guava User Guide section on <a href=
* "http://code.google.com/p/guava-libraries/wiki/CollectionUtilitiesExplained#Iterables">
* {@code Iterators}</a>.
*
* @author Kevin Bourrillion
* @author Jared Levy
* @since 2.0 (imported from Google Collections Library)
*/
@GwtCompatible(emulated = true)
public final class Iterators {
private Iterators() {}
static final UnmodifiableIterator<Object> EMPTY_ITERATOR
= new UnmodifiableIterator<Object>() {
@Override
public boolean hasNext() {
return false;
}
@Override
public Object next() {
throw new NoSuchElementException();
}
};
/**
* Returns the empty iterator.
*
* <p>The {@link Iterable} equivalent of this method is {@link
* ImmutableSet#of()}.
*/
// Casting to any type is safe since there are no actual elements.
@SuppressWarnings("unchecked")
public static <T> UnmodifiableIterator<T> emptyIterator() {
return (UnmodifiableIterator<T>) EMPTY_ITERATOR;
}
private static final Iterator<Object> EMPTY_MODIFIABLE_ITERATOR =
new Iterator<Object>() {
@Override public boolean hasNext() {
return false;
}
@Override public Object next() {
throw new NoSuchElementException();
}
@Override public void remove() {
throw new IllegalStateException();
}
};
/**
* Returns the empty {@code Iterator} that throws
* {@link IllegalStateException} instead of
* {@link UnsupportedOperationException} on a call to
* {@link Iterator#remove()}.
*/
// Casting to any type is safe since there are no actual elements.
@SuppressWarnings("unchecked")
static <T> Iterator<T> emptyModifiableIterator() {
return (Iterator<T>) EMPTY_MODIFIABLE_ITERATOR;
}
/** Returns an unmodifiable view of {@code iterator}. */
public static <T> UnmodifiableIterator<T> unmodifiableIterator(
final Iterator<T> iterator) {
checkNotNull(iterator);
if (iterator instanceof UnmodifiableIterator) {
return (UnmodifiableIterator<T>) iterator;
}
return new UnmodifiableIterator<T>() {
@Override
public boolean hasNext() {
return iterator.hasNext();
}
@Override
public T next() {
return iterator.next();
}
};
}
/**
* Simply returns its argument.
*
* @deprecated no need to use this
* @since 10.0
*/
@Deprecated public static <T> UnmodifiableIterator<T> unmodifiableIterator(
UnmodifiableIterator<T> iterator) {
return checkNotNull(iterator);
}
/**
* Returns the number of elements remaining in {@code iterator}. The iterator
* will be left exhausted: its {@code hasNext()} method will return
* {@code false}.
*/
public static int size(Iterator<?> iterator) {
int count = 0;
while (iterator.hasNext()) {
iterator.next();
count++;
}
return count;
}
/**
* Returns {@code true} if {@code iterator} contains {@code element}.
*/
public static boolean contains(Iterator<?> iterator, @Nullable Object element)
{
if (element == null) {
while (iterator.hasNext()) {
if (iterator.next() == null) {
return true;
}
}
} else {
while (iterator.hasNext()) {
if (element.equals(iterator.next())) {
return true;
}
}
}
return false;
}
/**
* Traverses an iterator and removes every element that belongs to the
* provided collection. The iterator will be left exhausted: its
* {@code hasNext()} method will return {@code false}.
*
* @param removeFrom the iterator to (potentially) remove elements from
* @param elementsToRemove the elements to remove
* @return {@code true} if any element was removed from {@code iterator}
*/
public static boolean removeAll(
Iterator<?> removeFrom, Collection<?> elementsToRemove) {
checkNotNull(elementsToRemove);
boolean modified = false;
while (removeFrom.hasNext()) {
if (elementsToRemove.contains(removeFrom.next())) {
removeFrom.remove();
modified = true;
}
}
return modified;
}
/**
* Removes every element that satisfies the provided predicate from the
* iterator. The iterator will be left exhausted: its {@code hasNext()}
* method will return {@code false}.
*
* @param removeFrom the iterator to (potentially) remove elements from
* @param predicate a predicate that determines whether an element should
* be removed
* @return {@code true} if any elements were removed from the iterator
* @since 2.0
*/
public static <T> boolean removeIf(
Iterator<T> removeFrom, Predicate<? super T> predicate) {
checkNotNull(predicate);
boolean modified = false;
while (removeFrom.hasNext()) {
if (predicate.apply(removeFrom.next())) {
removeFrom.remove();
modified = true;
}
}
return modified;
}
/**
* Traverses an iterator and removes every element that does not belong to the
* provided collection. The iterator will be left exhausted: its
* {@code hasNext()} method will return {@code false}.
*
* @param removeFrom the iterator to (potentially) remove elements from
* @param elementsToRetain the elements to retain
* @return {@code true} if any element was removed from {@code iterator}
*/
public static boolean retainAll(
Iterator<?> removeFrom, Collection<?> elementsToRetain) {
checkNotNull(elementsToRetain);
boolean modified = false;
while (removeFrom.hasNext()) {
if (!elementsToRetain.contains(removeFrom.next())) {
removeFrom.remove();
modified = true;
}
}
return modified;
}
/**
* Determines whether two iterators contain equal elements in the same order.
* More specifically, this method returns {@code true} if {@code iterator1}
* and {@code iterator2} contain the same number of elements and every element
* of {@code iterator1} is equal to the corresponding element of
* {@code iterator2}.
*
* <p>Note that this will modify the supplied iterators, since they will have
* been advanced some number of elements forward.
*/
public static boolean elementsEqual(
Iterator<?> iterator1, Iterator<?> iterator2) {
while (iterator1.hasNext()) {
if (!iterator2.hasNext()) {
return false;
}
Object o1 = iterator1.next();
Object o2 = iterator2.next();
if (!Objects.equal(o1, o2)) {
return false;
}
}
return !iterator2.hasNext();
}
/**
* Returns a string representation of {@code iterator}, with the format
* {@code [e1, e2, ..., en]}. The iterator will be left exhausted: its
* {@code hasNext()} method will return {@code false}.
*/
public static String toString(Iterator<?> iterator) {
if (!iterator.hasNext()) {
return "[]";
}
StringBuilder builder = new StringBuilder();
builder.append('[').append(iterator.next());
while (iterator.hasNext()) {
builder.append(", ").append(iterator.next());
}
return builder.append(']').toString();
}
/**
* Returns the single element contained in {@code iterator}.
*
* @throws NoSuchElementException if the iterator is empty
* @throws IllegalArgumentException if the iterator contains multiple
* elements. The state of the iterator is unspecified.
*/
public static <T> T getOnlyElement(Iterator<T> iterator) {
T first = iterator.next();
if (!iterator.hasNext()) {
return first;
}
StringBuilder sb = new StringBuilder();
sb.append("expected one element but was: <" + first);
for (int i = 0; i < 4 && iterator.hasNext(); i++) {
sb.append(", " + iterator.next());
}
if (iterator.hasNext()) {
sb.append(", ...");
}
sb.append('>');
throw new IllegalArgumentException(sb.toString());
}
/**
* Returns the single element contained in {@code iterator}, or {@code
* defaultValue} if the iterator is empty.
*
* @throws IllegalArgumentException if the iterator contains multiple
* elements. The state of the iterator is unspecified.
*/
public static <T> T getOnlyElement(
Iterator<T> iterator, @Nullable T defaultValue) {
return iterator.hasNext() ? getOnlyElement(iterator) : defaultValue;
}
/**
* Adds all elements in {@code iterator} to {@code collection}. The iterator
* will be left exhausted: its {@code hasNext()} method will return
* {@code false}.
*
* @return {@code true} if {@code collection} was modified as a result of this
* operation
*/
public static <T> boolean addAll(
Collection<T> addTo, Iterator<? extends T> iterator) {
checkNotNull(addTo);
boolean wasModified = false;
while (iterator.hasNext()) {
wasModified |= addTo.add(iterator.next());
}
return wasModified;
}
/**
* Returns the number of elements in the specified iterator that equal the
* specified object. The iterator will be left exhausted: its
* {@code hasNext()} method will return {@code false}.
*
* @see Collections#frequency
*/
public static int frequency(Iterator<?> iterator, @Nullable Object element) {
int result = 0;
if (element == null) {
while (iterator.hasNext()) {
if (iterator.next() == null) {
result++;
}
}
} else {
while (iterator.hasNext()) {
if (element.equals(iterator.next())) {
result++;
}
}
}
return result;
}
/**
* Returns an iterator that cycles indefinitely over the elements of {@code
* iterable}.
*
* <p>The returned iterator supports {@code remove()} if the provided iterator
* does. After {@code remove()} is called, subsequent cycles omit the removed
* element, which is no longer in {@code iterable}. The iterator's
* {@code hasNext()} method returns {@code true} until {@code iterable} is
* empty.
*
* <p><b>Warning:</b> Typical uses of the resulting iterator may produce an
* infinite loop. You should use an explicit {@code break} or be certain that
* you will eventually remove all the elements.
*/
public static <T> Iterator<T> cycle(final Iterable<T> iterable) {
checkNotNull(iterable);
return new Iterator<T>() {
Iterator<T> iterator = emptyIterator();
Iterator<T> removeFrom;
@Override
public boolean hasNext() {
if (!iterator.hasNext()) {
iterator = iterable.iterator();
}
return iterator.hasNext();
}
@Override
public T next() {
if (!hasNext()) {
throw new NoSuchElementException();
}
removeFrom = iterator;
return iterator.next();
}
@Override
public void remove() {
checkState(removeFrom != null,
"no calls to next() since last call to remove()");
removeFrom.remove();
removeFrom = null;
}
};
}
/**
* Returns an iterator that cycles indefinitely over the provided elements.
*
* <p>The returned iterator supports {@code remove()} if the provided iterator
* does. After {@code remove()} is called, subsequent cycles omit the removed
* element, but {@code elements} does not change. The iterator's
* {@code hasNext()} method returns {@code true} until all of the original
* elements have been removed.
*
* <p><b>Warning:</b> Typical uses of the resulting iterator may produce an
* infinite loop. You should use an explicit {@code break} or be certain that
* you will eventually remove all the elements.
*/
public static <T> Iterator<T> cycle(T... elements) {
return cycle(Lists.newArrayList(elements));
}
/**
* Combines two iterators into a single iterator. The returned iterator
* iterates across the elements in {@code a}, followed by the elements in
* {@code b}. The source iterators are not polled until necessary.
*
* <p>The returned iterator supports {@code remove()} when the corresponding
* input iterator supports it.
*/
@SuppressWarnings("unchecked")
public static <T> Iterator<T> concat(Iterator<? extends T> a,
Iterator<? extends T> b) {
checkNotNull(a);
checkNotNull(b);
return concat(Arrays.asList(a, b).iterator());
}
/**
* Combines three iterators into a single iterator. The returned iterator
* iterates across the elements in {@code a}, followed by the elements in
* {@code b}, followed by the elements in {@code c}. The source iterators
* are not polled until necessary.
*
* <p>The returned iterator supports {@code remove()} when the corresponding
* input iterator supports it.
*/
@SuppressWarnings("unchecked")
public static <T> Iterator<T> concat(Iterator<? extends T> a,
Iterator<? extends T> b, Iterator<? extends T> c) {
checkNotNull(a);
checkNotNull(b);
checkNotNull(c);
return concat(Arrays.asList(a, b, c).iterator());
}
/**
* Combines four iterators into a single iterator. The returned iterator
* iterates across the elements in {@code a}, followed by the elements in
* {@code b}, followed by the elements in {@code c}, followed by the elements
* in {@code d}. The source iterators are not polled until necessary.
*
* <p>The returned iterator supports {@code remove()} when the corresponding
* input iterator supports it.
*/
@SuppressWarnings("unchecked")
public static <T> Iterator<T> concat(Iterator<? extends T> a,
Iterator<? extends T> b, Iterator<? extends T> c,
Iterator<? extends T> d) {
checkNotNull(a);
checkNotNull(b);
checkNotNull(c);
checkNotNull(d);
return concat(Arrays.asList(a, b, c, d).iterator());
}
/**
* Combines multiple iterators into a single iterator. The returned iterator
* iterates across the elements of each iterator in {@code inputs}. The input
* iterators are not polled until necessary.
*
* <p>The returned iterator supports {@code remove()} when the corresponding
* input iterator supports it.
*
* @throws NullPointerException if any of the provided iterators is null
*/
public static <T> Iterator<T> concat(Iterator<? extends T>... inputs) {
return concat(ImmutableList.copyOf(inputs).iterator());
}
/**
* Combines multiple iterators into a single iterator. The returned iterator
* iterates across the elements of each iterator in {@code inputs}. The input
* iterators are not polled until necessary.
*
* <p>The returned iterator supports {@code remove()} when the corresponding
* input iterator supports it. The methods of the returned iterator may throw
* {@code NullPointerException} if any of the input iterators is null.
*/
public static <T> Iterator<T> concat(
final Iterator<? extends Iterator<? extends T>> inputs) {
checkNotNull(inputs);
return new Iterator<T>() {
Iterator<? extends T> current = emptyIterator();
Iterator<? extends T> removeFrom;
@Override
public boolean hasNext() {
// http://code.google.com/p/google-collections/issues/detail?id=151
// current.hasNext() might be relatively expensive, worth minimizing.
boolean currentHasNext;
// checkNotNull eager for GWT
// note: it must be here & not where 'current' is assigned,
// because otherwise we'll have called inputs.next() before throwing
// the first NPE, and the next time around we'll call inputs.next()
// again, incorrectly moving beyond the error.
while (!(currentHasNext = checkNotNull(current).hasNext())
&& inputs.hasNext()) {
current = inputs.next();
}
return currentHasNext;
}
@Override
public T next() {
if (!hasNext()) {
throw new NoSuchElementException();
}
removeFrom = current;
return current.next();
}
@Override
public void remove() {
checkState(removeFrom != null,
"no calls to next() since last call to remove()");
removeFrom.remove();
removeFrom = null;
}
};
}
/**
* Divides an iterator into unmodifiable sublists of the given size (the final
* list may be smaller). For example, partitioning an iterator containing
* {@code [a, b, c, d, e]} with a partition size of 3 yields {@code
* [[a, b, c], [d, e]]} -- an outer iterator containing two inner lists of
* three and two elements, all in the original order.
*
* <p>The returned lists implement {@link java.util.RandomAccess}.
*
* @param iterator the iterator to return a partitioned view of
* @param size the desired size of each partition (the last may be smaller)
* @return an iterator of immutable lists containing the elements of {@code
* iterator} divided into partitions
* @throws IllegalArgumentException if {@code size} is nonpositive
*/
public static <T> UnmodifiableIterator<List<T>> partition(
Iterator<T> iterator, int size) {
return partitionImpl(iterator, size, false);
}
/**
* Divides an iterator into unmodifiable sublists of the given size, padding
* the final iterator with null values if necessary. For example, partitioning
* an iterator containing {@code [a, b, c, d, e]} with a partition size of 3
* yields {@code [[a, b, c], [d, e, null]]} -- an outer iterator containing
* two inner lists of three elements each, all in the original order.
*
* <p>The returned lists implement {@link java.util.RandomAccess}.
*
* @param iterator the iterator to return a partitioned view of
* @param size the desired size of each partition
* @return an iterator of immutable lists containing the elements of {@code
* iterator} divided into partitions (the final iterable may have
* trailing null elements)
* @throws IllegalArgumentException if {@code size} is nonpositive
*/
public static <T> UnmodifiableIterator<List<T>> paddedPartition(
Iterator<T> iterator, int size) {
return partitionImpl(iterator, size, true);
}
private static <T> UnmodifiableIterator<List<T>> partitionImpl(
final Iterator<T> iterator, final int size, final boolean pad) {
checkNotNull(iterator);
checkArgument(size > 0);
return new UnmodifiableIterator<List<T>>() {
@Override
public boolean hasNext() {
return iterator.hasNext();
}
@Override
public List<T> next() {
if (!hasNext()) {
throw new NoSuchElementException();
}
Object[] array = new Object[size];
int count = 0;
for (; count < size && iterator.hasNext(); count++) {
array[count] = iterator.next();
}
for (int i = count; i < size; i++) {
array[i] = null; // for GWT
}
@SuppressWarnings("unchecked") // we only put Ts in it
List<T> list = Collections.unmodifiableList(
(List<T>) Arrays.asList(array));
return (pad || count == size) ? list : list.subList(0, count);
}
};
}
/**
* Returns the elements of {@code unfiltered} that satisfy a predicate.
*/
public static <T> UnmodifiableIterator<T> filter(
final Iterator<T> unfiltered, final Predicate<? super T> predicate) {
checkNotNull(unfiltered);
checkNotNull(predicate);
return new AbstractIterator<T>() {
@Override protected T computeNext() {
while (unfiltered.hasNext()) {
T element = unfiltered.next();
if (predicate.apply(element)) {
return element;
}
}
return endOfData();
}
};
}
/**
* Returns {@code true} if one or more elements returned by {@code iterator}
* satisfy the given predicate.
*/
public static <T> boolean any(
Iterator<T> iterator, Predicate<? super T> predicate) {
checkNotNull(predicate);
while (iterator.hasNext()) {
T element = iterator.next();
if (predicate.apply(element)) {
return true;
}
}
return false;
}
/**
* Returns {@code true} if every element returned by {@code iterator}
* satisfies the given predicate. If {@code iterator} is empty, {@code true}
* is returned.
*/
public static <T> boolean all(
Iterator<T> iterator, Predicate<? super T> predicate) {
checkNotNull(predicate);
while (iterator.hasNext()) {
T element = iterator.next();
if (!predicate.apply(element)) {
return false;
}
}
return true;
}
/**
* Returns the first element in {@code iterator} that satisfies the given
* predicate; use this method only when such an element is known to exist. If
* no such element is found, the iterator will be left exhausted: its {@code
* hasNext()} method will return {@code false}. If it is possible that
* <i>no</i> element will match, use {@link #tryFind)} or {@link
* #find(Iterator, Predicate, T)} instead.
*
* @throws NoSuchElementException if no element in {@code iterator} matches
* the given predicate
*/
public static <T> T find(
Iterator<T> iterator, Predicate<? super T> predicate) {
return filter(iterator, predicate).next();
}
/**
* Returns the first element in {@code iterator} that satisfies the given
* predicate. If no such element is found, {@code defaultValue} will be
* returned from this method and the iterator will be left exhausted: its
* {@code hasNext()} method will return {@code false}. Note that this can
* usually be handled more naturally using {@code
* tryFind(iterator, predicate).or(defaultValue)}.
*
* @since 7.0
*/
public static <T> T find(Iterator<T> iterator, Predicate<? super T> predicate,
@Nullable T defaultValue) {
UnmodifiableIterator<T> filteredIterator = filter(iterator, predicate);
return filteredIterator.hasNext() ? filteredIterator.next() : defaultValue;
}
/**
* Returns an {@link Optional} containing the first element in {@code
* iterator} that satisfies the given predicate, if such an element exists. If
* no such element is found, an empty {@link Optional} will be returned from
* this method and the the iterator will be left exhausted: its {@code
* hasNext()} method will return {@code false}.
*
* <p><b>Warning:</b> avoid using a {@code predicate} that matches {@code
* null}. If {@code null} is matched in {@code iterator}, a
* NullPointerException will be thrown.
*
* @since 11.0
*/
public static <T> Optional<T> tryFind(
Iterator<T> iterator, Predicate<? super T> predicate) {
UnmodifiableIterator<T> filteredIterator = filter(iterator, predicate);
return filteredIterator.hasNext()
? Optional.of(filteredIterator.next())
: Optional.<T>absent();
}
/**
* Returns the index in {@code iterator} of the first element that satisfies
* the provided {@code predicate}, or {@code -1} if the Iterator has no such
* elements.
*
* <p>More formally, returns the lowest index {@code i} such that
* {@code predicate.apply(Iterators.get(iterator, i))} returns {@code true},
* or {@code -1} if there is no such index.
*
* <p>If -1 is returned, the iterator will be left exhausted: its
* {@code hasNext()} method will return {@code false}. Otherwise,
* the iterator will be set to the element which satisfies the
* {@code predicate}.
*
* @since 2.0
*/
public static <T> int indexOf(
Iterator<T> iterator, Predicate<? super T> predicate) {
checkNotNull(predicate, "predicate");
int i = 0;
while (iterator.hasNext()) {
T current = iterator.next();
if (predicate.apply(current)) {
return i;
}
i++;
}
return -1;
}
/**
* Returns an iterator that applies {@code function} to each element of {@code
* fromIterator}.
*
* <p>The returned iterator supports {@code remove()} if the provided iterator
* does. After a successful {@code remove()} call, {@code fromIterator} no
* longer contains the corresponding element.
*/
public static <F, T> Iterator<T> transform(final Iterator<F> fromIterator,
final Function<? super F, ? extends T> function) {
checkNotNull(fromIterator);
checkNotNull(function);
return new Iterator<T>() {
@Override
public boolean hasNext() {
return fromIterator.hasNext();
}
@Override
public T next() {
F from = fromIterator.next();
return function.apply(from);
}
@Override
public void remove() {
fromIterator.remove();
}
};
}
/**
* Advances {@code iterator} {@code position + 1} times, returning the
* element at the {@code position}th position.
*
* @param position position of the element to return
* @return the element at the specified position in {@code iterator}
* @throws IndexOutOfBoundsException if {@code position} is negative or
* greater than or equal to the number of elements remaining in
* {@code iterator}
*/
public static <T> T get(Iterator<T> iterator, int position) {
checkNonnegative(position);
int skipped = 0;
while (iterator.hasNext()) {
T t = iterator.next();
if (skipped++ == position) {
return t;
}
}
throw new IndexOutOfBoundsException("position (" + position
+ ") must be less than the number of elements that remained ("
+ skipped + ")");
}
private static void checkNonnegative(int position) {
if (position < 0) {
throw new IndexOutOfBoundsException("position (" + position
+ ") must not be negative");
}
}
/**
* Advances {@code iterator} {@code position + 1} times, returning the
* element at the {@code position}th position or {@code defaultValue}
* otherwise.
*
* @param position position of the element to return
* @param defaultValue the default value to return if the iterator is empty
* or if {@code position} is greater than the number of elements
* remaining in {@code iterator}
* @return the element at the specified position in {@code iterator} or
* {@code defaultValue} if {@code iterator} produces fewer than
* {@code position + 1} elements.
* @throws IndexOutOfBoundsException if {@code position} is negative
* @since 4.0
*/
public static <T> T get(Iterator<T> iterator, int position,
@Nullable T defaultValue) {
checkNonnegative(position);
try {
return get(iterator, position);
} catch (IndexOutOfBoundsException e) {
return defaultValue;
}
}
/**
* Returns the next element in {@code iterator} or {@code defaultValue} if
* the iterator is empty. The {@link Iterables} analog to this method is
* {@link Iterables#getFirst}.
*
* @param defaultValue the default value to return if the iterator is empty
* @return the next element of {@code iterator} or the default value
* @since 7.0
*/
public static <T> T getNext(Iterator<T> iterator, @Nullable T defaultValue) {
return iterator.hasNext() ? iterator.next() : defaultValue;
}
/**
* Advances {@code iterator} to the end, returning the last element.
*
* @return the last element of {@code iterator}
* @throws NoSuchElementException if the iterator is empty
*/
public static <T> T getLast(Iterator<T> iterator) {
while (true) {
T current = iterator.next();
if (!iterator.hasNext()) {
return current;
}
}
}
/**
* Advances {@code iterator} to the end, returning the last element or
* {@code defaultValue} if the iterator is empty.
*
* @param defaultValue the default value to return if the iterator is empty
* @return the last element of {@code iterator}
* @since 3.0
*/
public static <T> T getLast(Iterator<T> iterator, @Nullable T defaultValue) {
return iterator.hasNext() ? getLast(iterator) : defaultValue;
}
/**
* Calls {@code next()} on {@code iterator}, either {@code numberToSkip} times
* or until {@code hasNext()} returns {@code false}, whichever comes first.
*
* @return the number of elements skipped
* @since 3.0
*/
@Beta
public static <T> int skip(Iterator<T> iterator, int numberToSkip) {
checkNotNull(iterator);
checkArgument(numberToSkip >= 0, "number to skip cannot be negative");
int i;
for (i = 0; i < numberToSkip && iterator.hasNext(); i++) {
iterator.next();
}
return i;
}
/**
* Creates an iterator returning the first {@code limitSize} elements of the
* given iterator. If the original iterator does not contain that many
* elements, the returned iterator will have the same behavior as the original
* iterator. The returned iterator supports {@code remove()} if the original
* iterator does.
*
* @param iterator the iterator to limit
* @param limitSize the maximum number of elements in the returned iterator
* @throws IllegalArgumentException if {@code limitSize} is negative
* @since 3.0
*/
public static <T> Iterator<T> limit(
final Iterator<T> iterator, final int limitSize) {
checkNotNull(iterator);
checkArgument(limitSize >= 0, "limit is negative");
return new Iterator<T>() {
private int count;
@Override
public boolean hasNext() {
return count < limitSize && iterator.hasNext();
}
@Override
public T next() {
if (!hasNext()) {
throw new NoSuchElementException();
}
count++;
return iterator.next();
}
@Override
public void remove() {
iterator.remove();
}
};
}
/**
* Returns a view of the supplied {@code iterator} that removes each element
* from the supplied {@code iterator} as it is returned.
*
* <p>The provided iterator must support {@link Iterator#remove()} or
* else the returned iterator will fail on the first call to {@code
* next}.
*
* @param iterator the iterator to remove and return elements from
* @return an iterator that removes and returns elements from the
* supplied iterator
* @since 2.0
*/
public static <T> Iterator<T> consumingIterator(final Iterator<T> iterator) {
checkNotNull(iterator);
return new UnmodifiableIterator<T>() {
@Override
public boolean hasNext() {
return iterator.hasNext();
}
@Override
public T next() {
T next = iterator.next();
iterator.remove();
return next;
}
};
}
// Methods only in Iterators, not in Iterables
/**
* Clears the iterator using its remove method.
*/
static void clear(Iterator<?> iterator) {
checkNotNull(iterator);
while (iterator.hasNext()) {
iterator.next();
iterator.remove();
}
}
/**
* Returns an iterator containing the elements of {@code array} in order. The
* returned iterator is a view of the array; subsequent changes to the array
* will be reflected in the iterator.
*
* <p><b>Note:</b> It is often preferable to represent your data using a
* collection type, for example using {@link Arrays#asList(Object[])}, making
* this method unnecessary.
*
* <p>The {@code Iterable} equivalent of this method is either {@link
* Arrays#asList(Object[])}, {@link ImmutableList#copyOf(Object[])}},
* or {@link ImmutableList#of}.
*/
public static <T> UnmodifiableIterator<T> forArray(final T... array) {
// TODO(kevinb): compare performance with Arrays.asList(array).iterator().
checkNotNull(array); // eager for GWT.
return new AbstractIndexedListIterator<T>(array.length) {
@Override protected T get(int index) {
return array[index];
}
};
}
/**
* Returns an iterator containing the elements in the specified range of
* {@code array} in order. The returned iterator is a view of the array;
* subsequent changes to the array will be reflected in the iterator.
*
* <p>The {@code Iterable} equivalent of this method is {@code
* Arrays.asList(array).subList(offset, offset + length)}.
*
* @param array array to read elements out of
* @param offset index of first array element to retrieve
* @param length number of elements in iteration
* @throws IndexOutOfBoundsException if {@code offset} is negative, {@code
* length} is negative, or {@code offset + length > array.length}
*/
static <T> UnmodifiableIterator<T> forArray(
final T[] array, final int offset, int length) {
checkArgument(length >= 0);
int end = offset + length;
// Technically we should give a slightly more descriptive error on overflow
Preconditions.checkPositionIndexes(offset, end, array.length);
/*
* We can't use call the two-arg constructor with arguments (offset, end)
* because the returned Iterator is a ListIterator that may be moved back
* past the beginning of the iteration.
*/
return new AbstractIndexedListIterator<T>(length) {
@Override protected T get(int index) {
return array[offset + index];
}
};
}
/**
* Returns an iterator containing only {@code value}.
*
* <p>The {@link Iterable} equivalent of this method is {@link
* Collections#singleton}.
*/
public static <T> UnmodifiableIterator<T> singletonIterator(
@Nullable final T value) {
return new UnmodifiableIterator<T>() {
boolean done;
@Override
public boolean hasNext() {
return !done;
}
@Override
public T next() {
if (done) {
throw new NoSuchElementException();
}
done = true;
return value;
}
};
}
/**
* Adapts an {@code Enumeration} to the {@code Iterator} interface.
*
* <p>This method has no equivalent in {@link Iterables} because viewing an
* {@code Enumeration} as an {@code Iterable} is impossible. However, the
* contents can be <i>copied</i> into a collection using {@link
* Collections#list}.
*/
public static <T> UnmodifiableIterator<T> forEnumeration(
final Enumeration<T> enumeration) {
checkNotNull(enumeration);
return new UnmodifiableIterator<T>() {
@Override
public boolean hasNext() {
return enumeration.hasMoreElements();
}
@Override
public T next() {
return enumeration.nextElement();
}
};
}
/**
* Adapts an {@code Iterator} to the {@code Enumeration} interface.
*
* <p>The {@code Iterable} equivalent of this method is either {@link
* Collections#enumeration} (if you have a {@link Collection}), or
* {@code Iterators.asEnumeration(collection.iterator())}.
*/
public static <T> Enumeration<T> asEnumeration(final Iterator<T> iterator) {
checkNotNull(iterator);
return new Enumeration<T>() {
@Override
public boolean hasMoreElements() {
return iterator.hasNext();
}
@Override
public T nextElement() {
return iterator.next();
}
};
}
/**
* Implementation of PeekingIterator that avoids peeking unless necessary.
*/
private static class PeekingImpl<E> implements PeekingIterator<E> {
private final Iterator<? extends E> iterator;
private boolean hasPeeked;
private E peekedElement;
public PeekingImpl(Iterator<? extends E> iterator) {
this.iterator = checkNotNull(iterator);
}
@Override
public boolean hasNext() {
return hasPeeked || iterator.hasNext();
}
@Override
public E next() {
if (!hasPeeked) {
return iterator.next();
}
E result = peekedElement;
hasPeeked = false;
peekedElement = null;
return result;
}
@Override
public void remove() {
checkState(!hasPeeked, "Can't remove after you've peeked at next");
iterator.remove();
}
@Override
public E peek() {
if (!hasPeeked) {
peekedElement = iterator.next();
hasPeeked = true;
}
return peekedElement;
}
}
/**
* Returns a {@code PeekingIterator} backed by the given iterator.
*
* <p>Calls to the {@code peek} method with no intervening calls to {@code
* next} do not affect the iteration, and hence return the same object each
* time. A subsequent call to {@code next} is guaranteed to return the same
* object again. For example: <pre> {@code
*
* PeekingIterator<String> peekingIterator =
* Iterators.peekingIterator(Iterators.forArray("a", "b"));
* String a1 = peekingIterator.peek(); // returns "a"
* String a2 = peekingIterator.peek(); // also returns "a"
* String a3 = peekingIterator.next(); // also returns "a"}</pre>
*
* Any structural changes to the underlying iteration (aside from those
* performed by the iterator's own {@link PeekingIterator#remove()} method)
* will leave the iterator in an undefined state.
*
* <p>The returned iterator does not support removal after peeking, as
* explained by {@link PeekingIterator#remove()}.
*
* <p>Note: If the given iterator is already a {@code PeekingIterator},
* it <i>might</i> be returned to the caller, although this is neither
* guaranteed to occur nor required to be consistent. For example, this
* method <i>might</i> choose to pass through recognized implementations of
* {@code PeekingIterator} when the behavior of the implementation is
* known to meet the contract guaranteed by this method.
*
* <p>There is no {@link Iterable} equivalent to this method, so use this
* method to wrap each individual iterator as it is generated.
*
* @param iterator the backing iterator. The {@link PeekingIterator} assumes
* ownership of this iterator, so users should cease making direct calls
* to it after calling this method.
* @return a peeking iterator backed by that iterator. Apart from the
* additional {@link PeekingIterator#peek()} method, this iterator behaves
* exactly the same as {@code iterator}.
*/
public static <T> PeekingIterator<T> peekingIterator(
Iterator<? extends T> iterator) {
if (iterator instanceof PeekingImpl) {
// Safe to cast <? extends T> to <T> because PeekingImpl only uses T
// covariantly (and cannot be subclassed to add non-covariant uses).
@SuppressWarnings("unchecked")
PeekingImpl<T> peeking = (PeekingImpl<T>) iterator;
return peeking;
}
return new PeekingImpl<T>(iterator);
}
/**
* Simply returns its argument.
*
* @deprecated no need to use this
* @since 10.0
*/
@Deprecated public static <T> PeekingIterator<T> peekingIterator(
PeekingIterator<T> iterator) {
return checkNotNull(iterator);
}
/**
* Returns an iterator over the merged contents of all given
* {@code iterators}, traversing every element of the input iterators.
* Equivalent entries will not be de-duplicated.
*
* <p>Callers must ensure that the source {@code iterators} are in
* non-descending order as this method does not sort its input.
*
* <p>For any equivalent elements across all {@code iterators}, it is
* undefined which element is returned first.
*
* @since 11.0
*/
@Beta
public static <T> UnmodifiableIterator<T> mergeSorted(
Iterable<? extends Iterator<? extends T>> iterators,
Comparator<? super T> comparator) {
checkNotNull(iterators, "iterators");
checkNotNull(comparator, "comparator");
return new MergingIterator<T>(iterators, comparator);
}
/**
* An iterator that performs a lazy N-way merge, calculating the next value
* each time the iterator is polled. This amortizes the sorting cost over the
* iteration and requires less memory than sorting all elements at once.
*
* <p>Retrieving a single element takes approximately O(log(M)) time, where M
* is the number of iterators. (Retrieving all elements takes approximately
* O(N*log(M)) time, where N is the total number of elements.)
*/
private static class MergingIterator<T> extends AbstractIterator<T> {
final Queue<PeekingIterator<T>> queue;
final Comparator<? super T> comparator;
public MergingIterator(Iterable<? extends Iterator<? extends T>> iterators,
Comparator<? super T> itemComparator) {
this.comparator = itemComparator;
// A comparator that's used by the heap, allowing the heap
// to be sorted based on the top of each iterator.
Comparator<PeekingIterator<T>> heapComparator =
new Comparator<PeekingIterator<T>>() {
@Override
public int compare(PeekingIterator<T> o1, PeekingIterator<T> o2) {
return comparator.compare(o1.peek(), o2.peek());
}
};
queue = new PriorityQueue<PeekingIterator<T>>(2, heapComparator);
for (Iterator<? extends T> iterator : iterators) {
if (iterator.hasNext()) {
queue.add(Iterators.peekingIterator(iterator));
}
}
}
@Override
protected T computeNext() {
if (queue.isEmpty()) {
return endOfData();
}
PeekingIterator<T> nextIter = queue.poll();
T next = nextIter.next();
if (nextIter.hasNext()) {
queue.add(nextIter);
}
return next;
}
}
}
| Java |
/*
* Copyright (C) 2009 The Guava Authors
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package com.google.common.collect;
import java.util.Collections;
import java.util.Map;
/**
* GWT emulation of {@link ImmutableBiMap}.
*
* @author Hayward Chan
*/
public abstract class ImmutableBiMap<K, V> extends ImmutableMap<K,V>
implements BiMap<K, V> {
private static final ImmutableBiMap<Object, Object> EMPTY_IMMUTABLE_BIMAP
= new EmptyBiMap();
// Casting to any type is safe because the set will never hold any elements.
@SuppressWarnings("unchecked")
public static <K, V> ImmutableBiMap<K, V> of() {
return (ImmutableBiMap<K, V>) EMPTY_IMMUTABLE_BIMAP;
}
public static <K, V> ImmutableBiMap<K, V> of(K k1, V v1) {
return new RegularImmutableBiMap<K, V>(ImmutableMap.of(k1, v1));
}
public static <K, V> ImmutableBiMap<K, V> of(K k1, V v1, K k2, V v2) {
return new RegularImmutableBiMap<K, V>(ImmutableMap.of(k1, v1, k2, v2));
}
public static <K, V> ImmutableBiMap<K, V> of(
K k1, V v1, K k2, V v2, K k3, V v3) {
return new RegularImmutableBiMap<K, V>(ImmutableMap.of(
k1, v1, k2, v2, k3, v3));
}
public static <K, V> ImmutableBiMap<K, V> of(
K k1, V v1, K k2, V v2, K k3, V v3, K k4, V v4) {
return new RegularImmutableBiMap<K, V>(ImmutableMap.of(
k1, v1, k2, v2, k3, v3, k4, v4));
}
public static <K, V> ImmutableBiMap<K, V> of(
K k1, V v1, K k2, V v2, K k3, V v3, K k4, V v4, K k5, V v5) {
return new RegularImmutableBiMap<K, V>(ImmutableMap.of(
k1, v1, k2, v2, k3, v3, k4, v4, k5, v5));
}
public static <K, V> Builder<K, V> builder() {
return new Builder<K, V>();
}
public static final class Builder<K, V> extends ImmutableMap.Builder<K, V> {
public Builder() {}
@Override public Builder<K, V> put(K key, V value) {
super.put(key, value);
return this;
}
@Override public Builder<K, V> putAll(Map<? extends K, ? extends V> map) {
super.putAll(map);
return this;
}
@Override public ImmutableBiMap<K, V> build() {
ImmutableMap<K, V> map = super.build();
if (map.isEmpty()) {
return of();
}
return new RegularImmutableBiMap<K, V>(super.build());
}
}
public static <K, V> ImmutableBiMap<K, V> copyOf(
Map<? extends K, ? extends V> map) {
if (map instanceof ImmutableBiMap) {
@SuppressWarnings("unchecked") // safe since map is not writable
ImmutableBiMap<K, V> bimap = (ImmutableBiMap<K, V>) map;
return bimap;
}
if (map.isEmpty()) {
return of();
}
ImmutableMap<K, V> immutableMap = ImmutableMap.copyOf(map);
return new RegularImmutableBiMap<K, V>(immutableMap);
}
ImmutableBiMap(Map<K, V> delegate) {
super(delegate);
}
public abstract ImmutableBiMap<V, K> inverse();
@Override public ImmutableSet<V> values() {
return inverse().keySet();
}
public final V forcePut(K key, V value) {
throw new UnsupportedOperationException();
}
@SuppressWarnings("serial")
static class EmptyBiMap extends ImmutableBiMap<Object, Object> {
EmptyBiMap() {
super(Collections.emptyMap());
}
@Override public ImmutableBiMap<Object, Object> inverse() {
return this;
}
}
}
| Java |
/*
* Copyright (C) 2009 The Guava Authors
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package com.google.common.collect;
import static com.google.common.base.Preconditions.checkNotNull;
import static com.google.common.collect.Iterables.getOnlyElement;
import java.io.Serializable;
import java.util.Collections;
import java.util.List;
import java.util.Map;
import java.util.Set;
import javax.annotation.Nullable;
/**
* GWT emulation of {@link ImmutableMap}. For non sorted maps, it is a thin
* wrapper around {@link java.util.Collections#emptyMap()}, {@link
* Collections#singletonMap(Object, Object)} and {@link java.util.LinkedHashMap}
* for empty, singleton and regular maps respectively. For sorted maps, it's
* a thin wrapper around {@link java.util.TreeMap}.
*
* @see ImmutableSortedMap
*
* @author Hayward Chan
*/
public abstract class ImmutableMap<K, V> implements Map<K, V>, Serializable {
private transient final Map<K, V> delegate;
ImmutableMap() {
this.delegate = Collections.emptyMap();
}
ImmutableMap(Map<? extends K, ? extends V> delegate) {
this.delegate = Collections.unmodifiableMap(delegate);
}
@SuppressWarnings("unchecked")
ImmutableMap(Entry<? extends K, ? extends V>... entries) {
Map<K, V> delegate = Maps.newLinkedHashMap();
for (Entry<? extends K, ? extends V> entry : entries) {
K key = checkNotNull(entry.getKey());
V previous = delegate.put(key, checkNotNull(entry.getValue()));
if (previous != null) {
throw new IllegalArgumentException("duplicate key: " + key);
}
}
this.delegate = Collections.unmodifiableMap(delegate);
}
// Casting to any type is safe because the set will never hold any elements.
@SuppressWarnings("unchecked")
public static <K, V> ImmutableMap<K, V> of() {
return (ImmutableMap<K, V>) EmptyImmutableMap.INSTANCE;
}
public static <K, V> ImmutableMap<K, V> of(K k1, V v1) {
return new SingletonImmutableMap<K, V>(
checkNotNull(k1), checkNotNull(v1));
}
public static <K, V> ImmutableMap<K, V> of(K k1, V v1, K k2, V v2) {
return new RegularImmutableMap<K, V>(entryOf(k1, v1), entryOf(k2, v2));
}
public static <K, V> ImmutableMap<K, V> of(
K k1, V v1, K k2, V v2, K k3, V v3) {
return new RegularImmutableMap<K, V>(
entryOf(k1, v1), entryOf(k2, v2), entryOf(k3, v3));
}
public static <K, V> ImmutableMap<K, V> of(
K k1, V v1, K k2, V v2, K k3, V v3, K k4, V v4) {
return new RegularImmutableMap<K, V>(
entryOf(k1, v1), entryOf(k2, v2), entryOf(k3, v3), entryOf(k4, v4));
}
public static <K, V> ImmutableMap<K, V> of(
K k1, V v1, K k2, V v2, K k3, V v3, K k4, V v4, K k5, V v5) {
return new RegularImmutableMap<K, V>(entryOf(k1, v1),
entryOf(k2, v2), entryOf(k3, v3), entryOf(k4, v4), entryOf(k5, v5));
}
// looking for of() with > 5 entries? Use the builder instead.
public static <K, V> Builder<K, V> builder() {
return new Builder<K, V>();
}
static <K, V> Entry<K, V> entryOf(K key, V value) {
return Maps.immutableEntry(checkNotNull(key), checkNotNull(value));
}
public static class Builder<K, V> {
final List<Entry<K, V>> entries = Lists.newArrayList();
public Builder() {}
public Builder<K, V> put(K key, V value) {
entries.add(entryOf(key, value));
return this;
}
public Builder<K, V> put(Entry<? extends K, ? extends V> entry) {
if (entry instanceof ImmutableEntry<?, ?>) {
checkNotNull(entry.getKey());
checkNotNull(entry.getValue());
@SuppressWarnings("unchecked") // all supported methods are covariant
Entry<K, V> immutableEntry = (Entry<K, V>) entry;
entries.add(immutableEntry);
} else {
entries.add(entryOf((K) entry.getKey(), (V) entry.getValue()));
}
return this;
}
public Builder<K, V> putAll(Map<? extends K, ? extends V> map) {
for (Entry<? extends K, ? extends V> entry : map.entrySet()) {
put(entry.getKey(), entry.getValue());
}
return this;
}
public ImmutableMap<K, V> build() {
return fromEntryList(entries);
}
private static <K, V> ImmutableMap<K, V> fromEntryList(
List<Entry<K, V>> entries) {
int size = entries.size();
switch (size) {
case 0:
return of();
case 1:
Entry<K, V> entry = getOnlyElement(entries);
return new SingletonImmutableMap<K, V>(
entry.getKey(), entry.getValue());
default:
@SuppressWarnings("unchecked")
Entry<K, V>[] entryArray
= entries.toArray(new Entry[entries.size()]);
return new RegularImmutableMap<K, V>(entryArray);
}
}
}
public static <K, V> ImmutableMap<K, V> copyOf(
Map<? extends K, ? extends V> map) {
if ((map instanceof ImmutableMap) && !(map instanceof ImmutableSortedMap)) {
@SuppressWarnings("unchecked") // safe since map is not writable
ImmutableMap<K, V> kvMap = (ImmutableMap<K, V>) map;
return kvMap;
}
int size = map.size();
switch (size) {
case 0:
return of();
case 1:
Entry<? extends K, ? extends V> entry
= getOnlyElement(map.entrySet());
return ImmutableMap.<K, V>of(entry.getKey(), entry.getValue());
default:
Map<K, V> orderPreservingCopy = Maps.newLinkedHashMap();
for (Entry<? extends K, ? extends V> e : map.entrySet()) {
orderPreservingCopy.put(
checkNotNull(e.getKey()), checkNotNull(e.getValue()));
}
return new RegularImmutableMap<K, V>(orderPreservingCopy);
}
}
boolean isPartialView(){
return false;
}
public final V put(K k, V v) {
throw new UnsupportedOperationException();
}
public final V remove(Object o) {
throw new UnsupportedOperationException();
}
public final void putAll(Map<? extends K, ? extends V> map) {
throw new UnsupportedOperationException();
}
public final void clear() {
throw new UnsupportedOperationException();
}
public final boolean isEmpty() {
return delegate.isEmpty();
}
public final boolean containsKey(@Nullable Object key) {
return Maps.safeContainsKey(delegate, key);
}
public final boolean containsValue(@Nullable Object value) {
return delegate.containsValue(value);
}
public final V get(@Nullable Object key) {
return (key == null) ? null : Maps.safeGet(delegate, key);
}
private transient ImmutableSet<Entry<K, V>> cachedEntrySet = null;
public final ImmutableSet<Entry<K, V>> entrySet() {
if (cachedEntrySet != null) {
return cachedEntrySet;
}
return cachedEntrySet = ImmutableSet.unsafeDelegate(
new ForwardingSet<Entry<K, V>>() {
@Override protected Set<Entry<K, V>> delegate() {
return delegate.entrySet();
}
@Override public boolean contains(Object object) {
if (object instanceof Entry<?, ?>
&& ((Entry<?, ?>) object).getKey() == null) {
return false;
}
try {
return super.contains(object);
} catch (ClassCastException e) {
return false;
}
}
@Override public <T> T[] toArray(T[] array) {
T[] result = super.toArray(array);
if (size() < result.length) {
// It works around a GWT bug where elements after last is not
// properly null'ed.
result[size()] = null;
}
return result;
}
});
}
private transient ImmutableSet<K> cachedKeySet = null;
public ImmutableSet<K> keySet() {
if (cachedKeySet != null) {
return cachedKeySet;
}
return cachedKeySet = ImmutableSet.unsafeDelegate(delegate.keySet());
}
private transient ImmutableCollection<V> cachedValues = null;
public ImmutableCollection<V> values() {
if (cachedValues != null) {
return cachedValues;
}
return cachedValues = ImmutableCollection.unsafeDelegate(delegate.values());
}
public int size() {
return delegate.size();
}
@Override public boolean equals(@Nullable Object object) {
return delegate.equals(object);
}
@Override public int hashCode() {
return delegate.hashCode();
}
@Override public String toString() {
return delegate.toString();
}
}
| Java |
/*
* Copyright (C) 2009 The Guava Authors
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package com.google.common.collect;
import com.google.common.base.Function;
import com.google.gwt.user.client.Timer;
import java.util.LinkedHashMap;
import java.util.Map;
import java.util.concurrent.ConcurrentHashMap;
import java.util.concurrent.ConcurrentMap;
import java.util.concurrent.TimeUnit;
/**
* MapMaker emulation. Since Javascript is single-threaded and have no references, this reduces to
* the creation of expiring and computing maps.
*
* @author Charles Fry
*/
public class MapMaker extends GenericMapMaker<Object, Object> {
// TODO(fry,user): ConcurrentHashMap never throws a CME when mutating the map during iteration, but
// this implementation (based on a LHM) does. This will all be replaced soon anyways, so leaving
// it as is for now.
private static class ExpiringComputingMap<K, V> extends LinkedHashMap<K, V>
implements ConcurrentMap<K, V> {
private final long expirationMillis;
private final Function<? super K, ? extends V> computer;
private final int maximumSize;
ExpiringComputingMap(long expirationMillis, int maximumSize, int initialCapacity,
float loadFactor) {
this(expirationMillis, null, maximumSize, initialCapacity, loadFactor);
}
ExpiringComputingMap(long expirationMillis, Function<? super K, ? extends V> computer,
int maximumSize, int initialCapacity, float loadFactor) {
super(initialCapacity, loadFactor, (maximumSize != -1));
this.expirationMillis = expirationMillis;
this.computer = computer;
this.maximumSize = maximumSize;
}
@Override
public V put(K key, V value) {
V result = super.put(key, value);
if (expirationMillis > 0) {
scheduleRemoval(key, value);
}
return result;
}
@Override
protected boolean removeEldestEntry(Map.Entry<K, V> ignored) {
return (maximumSize == -1) ? false : size() > maximumSize;
}
@Override
public V putIfAbsent(K key, V value) {
if (!containsKey(key)) {
return put(key, value);
} else {
return get(key);
}
}
@Override
public boolean remove(Object key, Object value) {
if (containsKey(key) && get(key).equals(value)) {
remove(key);
return true;
}
return false;
}
@Override
public boolean replace(K key, V oldValue, V newValue) {
if (containsKey(key) && get(key).equals(oldValue)) {
put(key, newValue);
return true;
}
return false;
}
@Override
public V replace(K key, V value) {
return containsKey(key) ? put(key, value) : null;
}
private void scheduleRemoval(final K key, final V value) {
// from MapMaker
/*
* TODO: Keep weak reference to map, too. Build a priority queue out of the entries themselves
* instead of creating a task per entry. Then, we could have one recurring task per map (which
* would clean the entire map and then reschedule itself depending upon when the next
* expiration comes). We also want to avoid removing an entry prematurely if the entry was set
* to the same value again.
*/
Timer timer = new Timer() {
@Override
public void run() {
remove(key, value);
}
};
timer.schedule((int) expirationMillis);
}
@Override
public V get(Object k) {
// from CustomConcurrentHashMap
V result = super.get(k);
if (result == null && computer != null) {
/*
* This cast isn't safe, but we can rely on the fact that K is almost always passed to
* Map.get(), and tools like IDEs and Findbugs can catch situations where this isn't the
* case.
*
* The alternative is to add an overloaded method, but the chances of a user calling get()
* instead of the new API and the risks inherent in adding a new API outweigh this little
* hole.
*/
@SuppressWarnings("unchecked")
K key = (K) k;
result = compute(key);
}
return result;
}
private V compute(K key) {
// from MapMaker
V value;
try {
value = computer.apply(key);
} catch (Throwable t) {
throw new ComputationException(t);
}
if (value == null) {
String message = computer + " returned null for key " + key + ".";
throw new NullPointerException(message);
}
put(key, value);
return value;
}
}
private int initialCapacity = 16;
private float loadFactor = 0.75f;
private long expirationMillis = 0;
private int maximumSize = -1;
private boolean useCustomMap;
public MapMaker() {}
@Override
public MapMaker initialCapacity(int initialCapacity) {
if (initialCapacity < 0) {
throw new IllegalArgumentException();
}
this.initialCapacity = initialCapacity;
return this;
}
public MapMaker loadFactor(float loadFactor) {
if (loadFactor <= 0) {
throw new IllegalArgumentException();
}
this.loadFactor = loadFactor;
return this;
}
@Override
public
MapMaker expiration(long duration, TimeUnit unit) {
return expireAfterWrite(duration, unit);
}
@Override
MapMaker expireAfterWrite(long duration, TimeUnit unit) {
if (expirationMillis != 0) {
throw new IllegalStateException(
"expiration time of " + expirationMillis + " ns was already set");
}
if (duration <= 0) {
throw new IllegalArgumentException("invalid duration: " + duration);
}
this.expirationMillis = unit.toMillis(duration);
useCustomMap = true;
return this;
}
@Override
MapMaker maximumSize(int maximumSize) {
if (this.maximumSize != -1) {
throw new IllegalStateException("maximum size of " + maximumSize + " was already set");
}
if (maximumSize < 0) {
throw new IllegalArgumentException("invalid maximum size: " + maximumSize);
}
this.maximumSize = maximumSize;
useCustomMap = true;
return this;
}
@Override
public MapMaker concurrencyLevel(int concurrencyLevel) {
if (concurrencyLevel < 1) {
throw new IllegalArgumentException("GWT only supports a concurrency level of 1");
}
// GWT technically only supports concurrencyLevel == 1, but we silently
// ignore other positive values.
return this;
}
@Override
MapMaker strongKeys() {
return this;
}
@Override
MapMaker strongValues() {
return this;
}
@Override
public <K, V> ConcurrentMap<K, V> makeMap() {
return useCustomMap
? new ExpiringComputingMap<K, V>(expirationMillis, null, maximumSize, initialCapacity,
loadFactor)
: new ConcurrentHashMap<K, V>(initialCapacity, loadFactor);
}
@Override
public <K, V> ConcurrentMap<K, V> makeComputingMap(Function<? super K, ? extends V> computer) {
return new ExpiringComputingMap<K, V>(expirationMillis, computer, maximumSize, initialCapacity,
loadFactor);
}
}
| Java |
/*
* Copyright (C) 2008 The Guava Authors
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package com.google.common.collect;
import com.google.common.annotations.Beta;
import com.google.common.annotations.GwtCompatible;
import java.util.Collection;
import java.util.Comparator;
import java.util.Map.Entry;
import javax.annotation.Nullable;
/**
* An immutable {@link ListMultimap} with reliable user-specified key and value
* iteration order. Does not permit null keys or values.
*
* <p>Unlike {@link Multimaps#unmodifiableListMultimap(ListMultimap)}, which is
* a <i>view</i> of a separate multimap which can still change, an instance of
* {@code ImmutableListMultimap} contains its own data and will <i>never</i>
* change. {@code ImmutableListMultimap} is convenient for
* {@code public static final} multimaps ("constant multimaps") and also lets
* you easily make a "defensive copy" of a multimap provided to your class by
* a caller.
*
* <p><b>Note:</b> Although this class is not final, it cannot be subclassed as
* it has no public or protected constructors. Thus, instances of this class
* are guaranteed to be immutable.
*
* <p>See the Guava User Guide article on <a href=
* "http://code.google.com/p/guava-libraries/wiki/ImmutableCollectionsExplained">
* immutable collections</a>.
*
* @author Jared Levy
* @since 2.0 (imported from Google Collections Library)
*/
@GwtCompatible(serializable = true, emulated = true)
public class ImmutableListMultimap<K, V>
extends ImmutableMultimap<K, V>
implements ListMultimap<K, V> {
/** Returns the empty multimap. */
// Casting is safe because the multimap will never hold any elements.
@SuppressWarnings("unchecked")
public static <K, V> ImmutableListMultimap<K, V> of() {
return (ImmutableListMultimap<K, V>) EmptyImmutableListMultimap.INSTANCE;
}
/**
* Returns an immutable multimap containing a single entry.
*/
public static <K, V> ImmutableListMultimap<K, V> of(K k1, V v1) {
ImmutableListMultimap.Builder<K, V> builder
= ImmutableListMultimap.builder();
builder.put(k1, v1);
return builder.build();
}
/**
* Returns an immutable multimap containing the given entries, in order.
*/
public static <K, V> ImmutableListMultimap<K, V> of(K k1, V v1, K k2, V v2) {
ImmutableListMultimap.Builder<K, V> builder
= ImmutableListMultimap.builder();
builder.put(k1, v1);
builder.put(k2, v2);
return builder.build();
}
/**
* Returns an immutable multimap containing the given entries, in order.
*/
public static <K, V> ImmutableListMultimap<K, V> of(
K k1, V v1, K k2, V v2, K k3, V v3) {
ImmutableListMultimap.Builder<K, V> builder
= ImmutableListMultimap.builder();
builder.put(k1, v1);
builder.put(k2, v2);
builder.put(k3, v3);
return builder.build();
}
/**
* Returns an immutable multimap containing the given entries, in order.
*/
public static <K, V> ImmutableListMultimap<K, V> of(
K k1, V v1, K k2, V v2, K k3, V v3, K k4, V v4) {
ImmutableListMultimap.Builder<K, V> builder
= ImmutableListMultimap.builder();
builder.put(k1, v1);
builder.put(k2, v2);
builder.put(k3, v3);
builder.put(k4, v4);
return builder.build();
}
/**
* Returns an immutable multimap containing the given entries, in order.
*/
public static <K, V> ImmutableListMultimap<K, V> of(
K k1, V v1, K k2, V v2, K k3, V v3, K k4, V v4, K k5, V v5) {
ImmutableListMultimap.Builder<K, V> builder
= ImmutableListMultimap.builder();
builder.put(k1, v1);
builder.put(k2, v2);
builder.put(k3, v3);
builder.put(k4, v4);
builder.put(k5, v5);
return builder.build();
}
// looking for of() with > 5 entries? Use the builder instead.
/**
* Returns a new builder. The generated builder is equivalent to the builder
* created by the {@link Builder} constructor.
*/
public static <K, V> Builder<K, V> builder() {
return new Builder<K, V>();
}
/**
* A builder for creating immutable {@code ListMultimap} instances, especially
* {@code public static final} multimaps ("constant multimaps"). Example:
* <pre> {@code
*
* static final Multimap<String, Integer> STRING_TO_INTEGER_MULTIMAP =
* new ImmutableListMultimap.Builder<String, Integer>()
* .put("one", 1)
* .putAll("several", 1, 2, 3)
* .putAll("many", 1, 2, 3, 4, 5)
* .build();}</pre>
*
* Builder instances can be reused; it is safe to call {@link #build} multiple
* times to build multiple multimaps in series. Each multimap contains the
* key-value mappings in the previously created multimaps.
*
* @since 2.0 (imported from Google Collections Library)
*/
public static final class Builder<K, V>
extends ImmutableMultimap.Builder<K, V> {
/**
* Creates a new builder. The returned builder is equivalent to the builder
* generated by {@link ImmutableListMultimap#builder}.
*/
public Builder() {}
@Override public Builder<K, V> put(K key, V value) {
super.put(key, value);
return this;
}
/**
* {@inheritDoc}
*
* @since 11.0
*/
@Override public Builder<K, V> put(
Entry<? extends K, ? extends V> entry) {
super.put(entry);
return this;
}
@Override public Builder<K, V> putAll(K key, Iterable<? extends V> values) {
super.putAll(key, values);
return this;
}
@Override public Builder<K, V> putAll(K key, V... values) {
super.putAll(key, values);
return this;
}
@Override public Builder<K, V> putAll(
Multimap<? extends K, ? extends V> multimap) {
super.putAll(multimap);
return this;
}
/**
* {@inheritDoc}
*
* @since 8.0
*/
@Beta @Override
public Builder<K, V> orderKeysBy(Comparator<? super K> keyComparator) {
super.orderKeysBy(keyComparator);
return this;
}
/**
* {@inheritDoc}
*
* @since 8.0
*/
@Beta @Override
public Builder<K, V> orderValuesBy(Comparator<? super V> valueComparator) {
super.orderValuesBy(valueComparator);
return this;
}
/**
* Returns a newly-created immutable list multimap.
*/
@Override public ImmutableListMultimap<K, V> build() {
return (ImmutableListMultimap<K, V>) super.build();
}
}
/**
* Returns an immutable multimap containing the same mappings as {@code
* multimap}. The generated multimap's key and value orderings correspond to
* the iteration ordering of the {@code multimap.asMap()} view.
*
* <p>Despite the method name, this method attempts to avoid actually copying
* the data when it is safe to do so. The exact circumstances under which a
* copy will or will not be performed are undocumented and subject to change.
*
* @throws NullPointerException if any key or value in {@code multimap} is
* null
*/
public static <K, V> ImmutableListMultimap<K, V> copyOf(
Multimap<? extends K, ? extends V> multimap) {
if (multimap.isEmpty()) {
return of();
}
// TODO(user): copy ImmutableSetMultimap by using asList() on the sets
if (multimap instanceof ImmutableListMultimap) {
@SuppressWarnings("unchecked") // safe since multimap is not writable
ImmutableListMultimap<K, V> kvMultimap
= (ImmutableListMultimap<K, V>) multimap;
if (!kvMultimap.isPartialView()) {
return kvMultimap;
}
}
ImmutableMap.Builder<K, ImmutableList<V>> builder = ImmutableMap.builder();
int size = 0;
for (Entry<? extends K, ? extends Collection<? extends V>> entry
: multimap.asMap().entrySet()) {
ImmutableList<V> list = ImmutableList.copyOf(entry.getValue());
if (!list.isEmpty()) {
builder.put(entry.getKey(), list);
size += list.size();
}
}
return new ImmutableListMultimap<K, V>(builder.build(), size);
}
ImmutableListMultimap(ImmutableMap<K, ImmutableList<V>> map, int size) {
super(map, size);
}
// views
/**
* Returns an immutable list of the values for the given key. If no mappings
* in the multimap have the provided key, an empty immutable list is
* returned. The values are in the same order as the parameters used to build
* this multimap.
*/
@Override public ImmutableList<V> get(@Nullable K key) {
// This cast is safe as its type is known in constructor.
ImmutableList<V> list = (ImmutableList<V>) map.get(key);
return (list == null) ? ImmutableList.<V>of() : list;
}
private transient ImmutableListMultimap<V, K> inverse;
/**
* {@inheritDoc}
*
* <p>Because an inverse of a list multimap can contain multiple pairs with the same key and
* value, this method returns an {@code ImmutableListMultimap} rather than the
* {@code ImmutableMultimap} specified in the {@code ImmutableMultimap} class.
*
* @since 11
*/
@Beta
public ImmutableListMultimap<V, K> inverse() {
ImmutableListMultimap<V, K> result = inverse;
return (result == null) ? (inverse = invert()) : result;
}
private ImmutableListMultimap<V, K> invert() {
Builder<V, K> builder = builder();
for (Entry<K, V> entry : entries()) {
builder.put(entry.getValue(), entry.getKey());
}
ImmutableListMultimap<V, K> invertedMultimap = builder.build();
invertedMultimap.inverse = this;
return invertedMultimap;
}
/**
* Guaranteed to throw an exception and leave the multimap unmodified.
*
* @throws UnsupportedOperationException always
*/
@Override public ImmutableList<V> removeAll(Object key) {
throw new UnsupportedOperationException();
}
/**
* Guaranteed to throw an exception and leave the multimap unmodified.
*
* @throws UnsupportedOperationException always
*/
@Override public ImmutableList<V> replaceValues(
K key, Iterable<? extends V> values) {
throw new UnsupportedOperationException();
}
}
| Java |
/*
* Copyright (C) 2007 The Guava Authors
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package com.google.common.collect;
import static com.google.common.base.Preconditions.checkNotNull;
import com.google.common.annotations.GwtCompatible;
import com.google.common.annotations.VisibleForTesting;
import java.io.Serializable;
import java.util.Collection;
import java.util.Comparator;
import java.util.Iterator;
import java.util.List;
import java.util.ListIterator;
import java.util.Map;
import java.util.RandomAccess;
import java.util.Set;
import java.util.SortedMap;
import java.util.SortedSet;
import javax.annotation.Nullable;
/**
* Synchronized collection views. The returned synchronized collection views are
* serializable if the backing collection and the mutex are serializable.
*
* <p>If {@code null} is passed as the {@code mutex} parameter to any of this
* class's top-level methods or inner class constructors, the created object
* uses itself as the synchronization mutex.
*
* <p>This class should be used by other collection classes only.
*
* @author Mike Bostock
* @author Jared Levy
*/
@GwtCompatible(emulated = true)
final class Synchronized {
private Synchronized() {}
static class SynchronizedObject implements Serializable {
final Object delegate;
final Object mutex;
SynchronizedObject(Object delegate, @Nullable Object mutex) {
this.delegate = checkNotNull(delegate);
this.mutex = (mutex == null) ? this : mutex;
}
Object delegate() {
return delegate;
}
// No equals and hashCode; see ForwardingObject for details.
@Override public String toString() {
synchronized (mutex) {
return delegate.toString();
}
}
// Serialization invokes writeObject only when it's private.
// The SynchronizedObject subclasses don't need a writeObject method since
// they don't contain any non-transient member variables, while the
// following writeObject() handles the SynchronizedObject members.
}
private static <E> Collection<E> collection(
Collection<E> collection, @Nullable Object mutex) {
return new SynchronizedCollection<E>(collection, mutex);
}
@VisibleForTesting static class SynchronizedCollection<E>
extends SynchronizedObject implements Collection<E> {
private SynchronizedCollection(
Collection<E> delegate, @Nullable Object mutex) {
super(delegate, mutex);
}
@SuppressWarnings("unchecked")
@Override Collection<E> delegate() {
return (Collection<E>) super.delegate();
}
@Override
public boolean add(E e) {
synchronized (mutex) {
return delegate().add(e);
}
}
@Override
public boolean addAll(Collection<? extends E> c) {
synchronized (mutex) {
return delegate().addAll(c);
}
}
@Override
public void clear() {
synchronized (mutex) {
delegate().clear();
}
}
@Override
public boolean contains(Object o) {
synchronized (mutex) {
return delegate().contains(o);
}
}
@Override
public boolean containsAll(Collection<?> c) {
synchronized (mutex) {
return delegate().containsAll(c);
}
}
@Override
public boolean isEmpty() {
synchronized (mutex) {
return delegate().isEmpty();
}
}
@Override
public Iterator<E> iterator() {
return delegate().iterator(); // manually synchronized
}
@Override
public boolean remove(Object o) {
synchronized (mutex) {
return delegate().remove(o);
}
}
@Override
public boolean removeAll(Collection<?> c) {
synchronized (mutex) {
return delegate().removeAll(c);
}
}
@Override
public boolean retainAll(Collection<?> c) {
synchronized (mutex) {
return delegate().retainAll(c);
}
}
@Override
public int size() {
synchronized (mutex) {
return delegate().size();
}
}
@Override
public Object[] toArray() {
synchronized (mutex) {
return delegate().toArray();
}
}
@Override
public <T> T[] toArray(T[] a) {
synchronized (mutex) {
return delegate().toArray(a);
}
}
private static final long serialVersionUID = 0;
}
@VisibleForTesting static <E> Set<E> set(Set<E> set, @Nullable Object mutex) {
return new SynchronizedSet<E>(set, mutex);
}
static class SynchronizedSet<E>
extends SynchronizedCollection<E> implements Set<E> {
SynchronizedSet(Set<E> delegate, @Nullable Object mutex) {
super(delegate, mutex);
}
@Override Set<E> delegate() {
return (Set<E>) super.delegate();
}
@Override public boolean equals(Object o) {
if (o == this) {
return true;
}
synchronized (mutex) {
return delegate().equals(o);
}
}
@Override public int hashCode() {
synchronized (mutex) {
return delegate().hashCode();
}
}
private static final long serialVersionUID = 0;
}
private static <E> SortedSet<E> sortedSet(
SortedSet<E> set, @Nullable Object mutex) {
return new SynchronizedSortedSet<E>(set, mutex);
}
static class SynchronizedSortedSet<E> extends SynchronizedSet<E>
implements SortedSet<E> {
SynchronizedSortedSet(SortedSet<E> delegate, @Nullable Object mutex) {
super(delegate, mutex);
}
@Override SortedSet<E> delegate() {
return (SortedSet<E>) super.delegate();
}
@Override
public Comparator<? super E> comparator() {
synchronized (mutex) {
return delegate().comparator();
}
}
@Override
public SortedSet<E> subSet(E fromElement, E toElement) {
synchronized (mutex) {
return sortedSet(delegate().subSet(fromElement, toElement), mutex);
}
}
@Override
public SortedSet<E> headSet(E toElement) {
synchronized (mutex) {
return sortedSet(delegate().headSet(toElement), mutex);
}
}
@Override
public SortedSet<E> tailSet(E fromElement) {
synchronized (mutex) {
return sortedSet(delegate().tailSet(fromElement), mutex);
}
}
@Override
public E first() {
synchronized (mutex) {
return delegate().first();
}
}
@Override
public E last() {
synchronized (mutex) {
return delegate().last();
}
}
private static final long serialVersionUID = 0;
}
private static <E> List<E> list(List<E> list, @Nullable Object mutex) {
return (list instanceof RandomAccess)
? new SynchronizedRandomAccessList<E>(list, mutex)
: new SynchronizedList<E>(list, mutex);
}
private static class SynchronizedList<E> extends SynchronizedCollection<E>
implements List<E> {
SynchronizedList(List<E> delegate, @Nullable Object mutex) {
super(delegate, mutex);
}
@Override List<E> delegate() {
return (List<E>) super.delegate();
}
@Override
public void add(int index, E element) {
synchronized (mutex) {
delegate().add(index, element);
}
}
@Override
public boolean addAll(int index, Collection<? extends E> c) {
synchronized (mutex) {
return delegate().addAll(index, c);
}
}
@Override
public E get(int index) {
synchronized (mutex) {
return delegate().get(index);
}
}
@Override
public int indexOf(Object o) {
synchronized (mutex) {
return delegate().indexOf(o);
}
}
@Override
public int lastIndexOf(Object o) {
synchronized (mutex) {
return delegate().lastIndexOf(o);
}
}
@Override
public ListIterator<E> listIterator() {
return delegate().listIterator(); // manually synchronized
}
@Override
public ListIterator<E> listIterator(int index) {
return delegate().listIterator(index); // manually synchronized
}
@Override
public E remove(int index) {
synchronized (mutex) {
return delegate().remove(index);
}
}
@Override
public E set(int index, E element) {
synchronized (mutex) {
return delegate().set(index, element);
}
}
@Override
public List<E> subList(int fromIndex, int toIndex) {
synchronized (mutex) {
return list(delegate().subList(fromIndex, toIndex), mutex);
}
}
@Override public boolean equals(Object o) {
if (o == this) {
return true;
}
synchronized (mutex) {
return delegate().equals(o);
}
}
@Override public int hashCode() {
synchronized (mutex) {
return delegate().hashCode();
}
}
private static final long serialVersionUID = 0;
}
private static class SynchronizedRandomAccessList<E>
extends SynchronizedList<E> implements RandomAccess {
SynchronizedRandomAccessList(List<E> list, @Nullable Object mutex) {
super(list, mutex);
}
private static final long serialVersionUID = 0;
}
static <E> Multiset<E> multiset(
Multiset<E> multiset, @Nullable Object mutex) {
if (multiset instanceof SynchronizedMultiset ||
multiset instanceof ImmutableMultiset) {
return multiset;
}
return new SynchronizedMultiset<E>(multiset, mutex);
}
private static class SynchronizedMultiset<E> extends SynchronizedCollection<E>
implements Multiset<E> {
transient Set<E> elementSet;
transient Set<Entry<E>> entrySet;
SynchronizedMultiset(Multiset<E> delegate, @Nullable Object mutex) {
super(delegate, mutex);
}
@Override Multiset<E> delegate() {
return (Multiset<E>) super.delegate();
}
@Override
public int count(Object o) {
synchronized (mutex) {
return delegate().count(o);
}
}
@Override
public int add(E e, int n) {
synchronized (mutex) {
return delegate().add(e, n);
}
}
@Override
public int remove(Object o, int n) {
synchronized (mutex) {
return delegate().remove(o, n);
}
}
@Override
public int setCount(E element, int count) {
synchronized (mutex) {
return delegate().setCount(element, count);
}
}
@Override
public boolean setCount(E element, int oldCount, int newCount) {
synchronized (mutex) {
return delegate().setCount(element, oldCount, newCount);
}
}
@Override
public Set<E> elementSet() {
synchronized (mutex) {
if (elementSet == null) {
elementSet = typePreservingSet(delegate().elementSet(), mutex);
}
return elementSet;
}
}
@Override
public Set<Entry<E>> entrySet() {
synchronized (mutex) {
if (entrySet == null) {
entrySet = typePreservingSet(delegate().entrySet(), mutex);
}
return entrySet;
}
}
@Override public boolean equals(Object o) {
if (o == this) {
return true;
}
synchronized (mutex) {
return delegate().equals(o);
}
}
@Override public int hashCode() {
synchronized (mutex) {
return delegate().hashCode();
}
}
private static final long serialVersionUID = 0;
}
static <K, V> Multimap<K, V> multimap(
Multimap<K, V> multimap, @Nullable Object mutex) {
if (multimap instanceof SynchronizedMultimap ||
multimap instanceof ImmutableMultimap) {
return multimap;
}
return new SynchronizedMultimap<K, V>(multimap, mutex);
}
private static class SynchronizedMultimap<K, V> extends SynchronizedObject
implements Multimap<K, V> {
transient Set<K> keySet;
transient Collection<V> valuesCollection;
transient Collection<Map.Entry<K, V>> entries;
transient Map<K, Collection<V>> asMap;
transient Multiset<K> keys;
@SuppressWarnings("unchecked")
@Override Multimap<K, V> delegate() {
return (Multimap<K, V>) super.delegate();
}
SynchronizedMultimap(Multimap<K, V> delegate, @Nullable Object mutex) {
super(delegate, mutex);
}
@Override
public int size() {
synchronized (mutex) {
return delegate().size();
}
}
@Override
public boolean isEmpty() {
synchronized (mutex) {
return delegate().isEmpty();
}
}
@Override
public boolean containsKey(Object key) {
synchronized (mutex) {
return delegate().containsKey(key);
}
}
@Override
public boolean containsValue(Object value) {
synchronized (mutex) {
return delegate().containsValue(value);
}
}
@Override
public boolean containsEntry(Object key, Object value) {
synchronized (mutex) {
return delegate().containsEntry(key, value);
}
}
@Override
public Collection<V> get(K key) {
synchronized (mutex) {
return typePreservingCollection(delegate().get(key), mutex);
}
}
@Override
public boolean put(K key, V value) {
synchronized (mutex) {
return delegate().put(key, value);
}
}
@Override
public boolean putAll(K key, Iterable<? extends V> values) {
synchronized (mutex) {
return delegate().putAll(key, values);
}
}
@Override
public boolean putAll(Multimap<? extends K, ? extends V> multimap) {
synchronized (mutex) {
return delegate().putAll(multimap);
}
}
@Override
public Collection<V> replaceValues(K key, Iterable<? extends V> values) {
synchronized (mutex) {
return delegate().replaceValues(key, values); // copy not synchronized
}
}
@Override
public boolean remove(Object key, Object value) {
synchronized (mutex) {
return delegate().remove(key, value);
}
}
@Override
public Collection<V> removeAll(Object key) {
synchronized (mutex) {
return delegate().removeAll(key); // copy not synchronized
}
}
@Override
public void clear() {
synchronized (mutex) {
delegate().clear();
}
}
@Override
public Set<K> keySet() {
synchronized (mutex) {
if (keySet == null) {
keySet = typePreservingSet(delegate().keySet(), mutex);
}
return keySet;
}
}
@Override
public Collection<V> values() {
synchronized (mutex) {
if (valuesCollection == null) {
valuesCollection = collection(delegate().values(), mutex);
}
return valuesCollection;
}
}
@Override
public Collection<Map.Entry<K, V>> entries() {
synchronized (mutex) {
if (entries == null) {
entries = typePreservingCollection(delegate().entries(), mutex);
}
return entries;
}
}
@Override
public Map<K, Collection<V>> asMap() {
synchronized (mutex) {
if (asMap == null) {
asMap = new SynchronizedAsMap<K, V>(delegate().asMap(), mutex);
}
return asMap;
}
}
@Override
public Multiset<K> keys() {
synchronized (mutex) {
if (keys == null) {
keys = multiset(delegate().keys(), mutex);
}
return keys;
}
}
@Override public boolean equals(Object o) {
if (o == this) {
return true;
}
synchronized (mutex) {
return delegate().equals(o);
}
}
@Override public int hashCode() {
synchronized (mutex) {
return delegate().hashCode();
}
}
private static final long serialVersionUID = 0;
}
static <K, V> ListMultimap<K, V> listMultimap(
ListMultimap<K, V> multimap, @Nullable Object mutex) {
if (multimap instanceof SynchronizedListMultimap ||
multimap instanceof ImmutableListMultimap) {
return multimap;
}
return new SynchronizedListMultimap<K, V>(multimap, mutex);
}
private static class SynchronizedListMultimap<K, V>
extends SynchronizedMultimap<K, V> implements ListMultimap<K, V> {
SynchronizedListMultimap(
ListMultimap<K, V> delegate, @Nullable Object mutex) {
super(delegate, mutex);
}
@Override ListMultimap<K, V> delegate() {
return (ListMultimap<K, V>) super.delegate();
}
@Override public List<V> get(K key) {
synchronized (mutex) {
return list(delegate().get(key), mutex);
}
}
@Override public List<V> removeAll(Object key) {
synchronized (mutex) {
return delegate().removeAll(key); // copy not synchronized
}
}
@Override public List<V> replaceValues(
K key, Iterable<? extends V> values) {
synchronized (mutex) {
return delegate().replaceValues(key, values); // copy not synchronized
}
}
private static final long serialVersionUID = 0;
}
static <K, V> SetMultimap<K, V> setMultimap(
SetMultimap<K, V> multimap, @Nullable Object mutex) {
if (multimap instanceof SynchronizedSetMultimap ||
multimap instanceof ImmutableSetMultimap) {
return multimap;
}
return new SynchronizedSetMultimap<K, V>(multimap, mutex);
}
private static class SynchronizedSetMultimap<K, V>
extends SynchronizedMultimap<K, V> implements SetMultimap<K, V> {
transient Set<Map.Entry<K, V>> entrySet;
SynchronizedSetMultimap(
SetMultimap<K, V> delegate, @Nullable Object mutex) {
super(delegate, mutex);
}
@Override SetMultimap<K, V> delegate() {
return (SetMultimap<K, V>) super.delegate();
}
@Override public Set<V> get(K key) {
synchronized (mutex) {
return set(delegate().get(key), mutex);
}
}
@Override public Set<V> removeAll(Object key) {
synchronized (mutex) {
return delegate().removeAll(key); // copy not synchronized
}
}
@Override public Set<V> replaceValues(
K key, Iterable<? extends V> values) {
synchronized (mutex) {
return delegate().replaceValues(key, values); // copy not synchronized
}
}
@Override public Set<Map.Entry<K, V>> entries() {
synchronized (mutex) {
if (entrySet == null) {
entrySet = set(delegate().entries(), mutex);
}
return entrySet;
}
}
private static final long serialVersionUID = 0;
}
static <K, V> SortedSetMultimap<K, V> sortedSetMultimap(
SortedSetMultimap<K, V> multimap, @Nullable Object mutex) {
if (multimap instanceof SynchronizedSortedSetMultimap) {
return multimap;
}
return new SynchronizedSortedSetMultimap<K, V>(multimap, mutex);
}
private static class SynchronizedSortedSetMultimap<K, V>
extends SynchronizedSetMultimap<K, V> implements SortedSetMultimap<K, V> {
SynchronizedSortedSetMultimap(
SortedSetMultimap<K, V> delegate, @Nullable Object mutex) {
super(delegate, mutex);
}
@Override SortedSetMultimap<K, V> delegate() {
return (SortedSetMultimap<K, V>) super.delegate();
}
@Override public SortedSet<V> get(K key) {
synchronized (mutex) {
return sortedSet(delegate().get(key), mutex);
}
}
@Override public SortedSet<V> removeAll(Object key) {
synchronized (mutex) {
return delegate().removeAll(key); // copy not synchronized
}
}
@Override public SortedSet<V> replaceValues(
K key, Iterable<? extends V> values) {
synchronized (mutex) {
return delegate().replaceValues(key, values); // copy not synchronized
}
}
@Override
public Comparator<? super V> valueComparator() {
synchronized (mutex) {
return delegate().valueComparator();
}
}
private static final long serialVersionUID = 0;
}
private static <E> Collection<E> typePreservingCollection(
Collection<E> collection, @Nullable Object mutex) {
if (collection instanceof SortedSet) {
return sortedSet((SortedSet<E>) collection, mutex);
}
if (collection instanceof Set) {
return set((Set<E>) collection, mutex);
}
if (collection instanceof List) {
return list((List<E>) collection, mutex);
}
return collection(collection, mutex);
}
private static <E> Set<E> typePreservingSet(
Set<E> set, @Nullable Object mutex) {
if (set instanceof SortedSet) {
return sortedSet((SortedSet<E>) set, mutex);
} else {
return set(set, mutex);
}
}
private static class SynchronizedAsMapEntries<K, V>
extends SynchronizedSet<Map.Entry<K, Collection<V>>> {
SynchronizedAsMapEntries(
Set<Map.Entry<K, Collection<V>>> delegate, @Nullable Object mutex) {
super(delegate, mutex);
}
@Override public Iterator<Map.Entry<K, Collection<V>>> iterator() {
// Must be manually synchronized.
final Iterator<Map.Entry<K, Collection<V>>> iterator = super.iterator();
return new ForwardingIterator<Map.Entry<K, Collection<V>>>() {
@Override protected Iterator<Map.Entry<K, Collection<V>>> delegate() {
return iterator;
}
@Override public Map.Entry<K, Collection<V>> next() {
final Map.Entry<K, Collection<V>> entry = iterator.next();
return new ForwardingMapEntry<K, Collection<V>>() {
@Override protected Map.Entry<K, Collection<V>> delegate() {
return entry;
}
@Override public Collection<V> getValue() {
return typePreservingCollection(entry.getValue(), mutex);
}
};
}
};
}
// See Collections.CheckedMap.CheckedEntrySet for details on attacks.
@Override public Object[] toArray() {
synchronized (mutex) {
return ObjectArrays.toArrayImpl(delegate());
}
}
@Override public <T> T[] toArray(T[] array) {
synchronized (mutex) {
return ObjectArrays.toArrayImpl(delegate(), array);
}
}
@Override public boolean contains(Object o) {
synchronized (mutex) {
return Maps.containsEntryImpl(delegate(), o);
}
}
@Override public boolean containsAll(Collection<?> c) {
synchronized (mutex) {
return Collections2.containsAllImpl(delegate(), c);
}
}
@Override public boolean equals(Object o) {
if (o == this) {
return true;
}
synchronized (mutex) {
return Sets.equalsImpl(delegate(), o);
}
}
@Override public boolean remove(Object o) {
synchronized (mutex) {
return Maps.removeEntryImpl(delegate(), o);
}
}
@Override public boolean removeAll(Collection<?> c) {
synchronized (mutex) {
return Iterators.removeAll(delegate().iterator(), c);
}
}
@Override public boolean retainAll(Collection<?> c) {
synchronized (mutex) {
return Iterators.retainAll(delegate().iterator(), c);
}
}
private static final long serialVersionUID = 0;
}
@VisibleForTesting
static <K, V> Map<K, V> map(Map<K, V> map, @Nullable Object mutex) {
return new SynchronizedMap<K, V>(map, mutex);
}
private static class SynchronizedMap<K, V> extends SynchronizedObject
implements Map<K, V> {
transient Set<K> keySet;
transient Collection<V> values;
transient Set<Map.Entry<K, V>> entrySet;
SynchronizedMap(Map<K, V> delegate, @Nullable Object mutex) {
super(delegate, mutex);
}
@SuppressWarnings("unchecked")
@Override Map<K, V> delegate() {
return (Map<K, V>) super.delegate();
}
@Override
public void clear() {
synchronized (mutex) {
delegate().clear();
}
}
@Override
public boolean containsKey(Object key) {
synchronized (mutex) {
return delegate().containsKey(key);
}
}
@Override
public boolean containsValue(Object value) {
synchronized (mutex) {
return delegate().containsValue(value);
}
}
@Override
public Set<Map.Entry<K, V>> entrySet() {
synchronized (mutex) {
if (entrySet == null) {
entrySet = set(delegate().entrySet(), mutex);
}
return entrySet;
}
}
@Override
public V get(Object key) {
synchronized (mutex) {
return delegate().get(key);
}
}
@Override
public boolean isEmpty() {
synchronized (mutex) {
return delegate().isEmpty();
}
}
@Override
public Set<K> keySet() {
synchronized (mutex) {
if (keySet == null) {
keySet = set(delegate().keySet(), mutex);
}
return keySet;
}
}
@Override
public V put(K key, V value) {
synchronized (mutex) {
return delegate().put(key, value);
}
}
@Override
public void putAll(Map<? extends K, ? extends V> map) {
synchronized (mutex) {
delegate().putAll(map);
}
}
@Override
public V remove(Object key) {
synchronized (mutex) {
return delegate().remove(key);
}
}
@Override
public int size() {
synchronized (mutex) {
return delegate().size();
}
}
@Override
public Collection<V> values() {
synchronized (mutex) {
if (values == null) {
values = collection(delegate().values(), mutex);
}
return values;
}
}
@Override public boolean equals(Object o) {
if (o == this) {
return true;
}
synchronized (mutex) {
return delegate().equals(o);
}
}
@Override public int hashCode() {
synchronized (mutex) {
return delegate().hashCode();
}
}
private static final long serialVersionUID = 0;
}
static <K, V> SortedMap<K, V> sortedMap(
SortedMap<K, V> sortedMap, @Nullable Object mutex) {
return new SynchronizedSortedMap<K, V>(sortedMap, mutex);
}
static class SynchronizedSortedMap<K, V> extends SynchronizedMap<K, V>
implements SortedMap<K, V> {
SynchronizedSortedMap(SortedMap<K, V> delegate, @Nullable Object mutex) {
super(delegate, mutex);
}
@Override SortedMap<K, V> delegate() {
return (SortedMap<K, V>) super.delegate();
}
@Override public Comparator<? super K> comparator() {
synchronized (mutex) {
return delegate().comparator();
}
}
@Override public K firstKey() {
synchronized (mutex) {
return delegate().firstKey();
}
}
@Override public SortedMap<K, V> headMap(K toKey) {
synchronized (mutex) {
return sortedMap(delegate().headMap(toKey), mutex);
}
}
@Override public K lastKey() {
synchronized (mutex) {
return delegate().lastKey();
}
}
@Override public SortedMap<K, V> subMap(K fromKey, K toKey) {
synchronized (mutex) {
return sortedMap(delegate().subMap(fromKey, toKey), mutex);
}
}
@Override public SortedMap<K, V> tailMap(K fromKey) {
synchronized (mutex) {
return sortedMap(delegate().tailMap(fromKey), mutex);
}
}
private static final long serialVersionUID = 0;
}
static <K, V> BiMap<K, V> biMap(BiMap<K, V> bimap, @Nullable Object mutex) {
if (bimap instanceof SynchronizedBiMap ||
bimap instanceof ImmutableBiMap) {
return bimap;
}
return new SynchronizedBiMap<K, V>(bimap, mutex, null);
}
@VisibleForTesting static class SynchronizedBiMap<K, V>
extends SynchronizedMap<K, V> implements BiMap<K, V>, Serializable {
private transient Set<V> valueSet;
private transient BiMap<V, K> inverse;
private SynchronizedBiMap(BiMap<K, V> delegate, @Nullable Object mutex,
@Nullable BiMap<V, K> inverse) {
super(delegate, mutex);
this.inverse = inverse;
}
@Override BiMap<K, V> delegate() {
return (BiMap<K, V>) super.delegate();
}
@Override public Set<V> values() {
synchronized (mutex) {
if (valueSet == null) {
valueSet = set(delegate().values(), mutex);
}
return valueSet;
}
}
@Override
public V forcePut(K key, V value) {
synchronized (mutex) {
return delegate().forcePut(key, value);
}
}
@Override
public BiMap<V, K> inverse() {
synchronized (mutex) {
if (inverse == null) {
inverse
= new SynchronizedBiMap<V, K>(delegate().inverse(), mutex, this);
}
return inverse;
}
}
private static final long serialVersionUID = 0;
}
private static class SynchronizedAsMap<K, V>
extends SynchronizedMap<K, Collection<V>> {
transient Set<Map.Entry<K, Collection<V>>> asMapEntrySet;
transient Collection<Collection<V>> asMapValues;
SynchronizedAsMap(Map<K, Collection<V>> delegate, @Nullable Object mutex) {
super(delegate, mutex);
}
@Override public Collection<V> get(Object key) {
synchronized (mutex) {
Collection<V> collection = super.get(key);
return (collection == null) ? null
: typePreservingCollection(collection, mutex);
}
}
@Override public Set<Map.Entry<K, Collection<V>>> entrySet() {
synchronized (mutex) {
if (asMapEntrySet == null) {
asMapEntrySet = new SynchronizedAsMapEntries<K, V>(
delegate().entrySet(), mutex);
}
return asMapEntrySet;
}
}
@Override public Collection<Collection<V>> values() {
synchronized (mutex) {
if (asMapValues == null) {
asMapValues
= new SynchronizedAsMapValues<V>(delegate().values(), mutex);
}
return asMapValues;
}
}
@Override public boolean containsValue(Object o) {
// values() and its contains() method are both synchronized.
return values().contains(o);
}
private static final long serialVersionUID = 0;
}
private static class SynchronizedAsMapValues<V>
extends SynchronizedCollection<Collection<V>> {
SynchronizedAsMapValues(
Collection<Collection<V>> delegate, @Nullable Object mutex) {
super(delegate, mutex);
}
@Override public Iterator<Collection<V>> iterator() {
// Must be manually synchronized.
final Iterator<Collection<V>> iterator = super.iterator();
return new ForwardingIterator<Collection<V>>() {
@Override protected Iterator<Collection<V>> delegate() {
return iterator;
}
@Override public Collection<V> next() {
return typePreservingCollection(iterator.next(), mutex);
}
};
}
private static final long serialVersionUID = 0;
}
}
| Java |
/*
* Copyright (C) 2009 The Guava Authors
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package com.google.common.collect;
/**
* GWT emulation of {@link EmptyImmutableMap}. In GWT, it is a thin wrapper
* around {@link java.util.Collections#emptyMap()}.
*
* @author Hayward Chan
*/
final class EmptyImmutableMap extends ImmutableMap<Object, Object> {
static final EmptyImmutableMap INSTANCE = new EmptyImmutableMap();
}
| Java |
/*
* Copyright (C) 2007 The Guava Authors
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package com.google.common.collect;
import static com.google.common.base.Preconditions.checkNotNull;
import com.google.common.annotations.GwtCompatible;
import java.util.EnumMap;
import java.util.Map;
import javax.annotation.Nullable;
/**
* A {@code BiMap} backed by an {@code EnumMap} instance for keys-to-values, and
* a {@code HashMap} instance for values-to-keys. Null keys are not permitted,
* but null values are. An {@code EnumHashBiMap} and its inverse are both
* serializable.
*
* <p>See the Guava User Guide article on <a href=
* "http://code.google.com/p/guava-libraries/wiki/NewCollectionTypesExplained#BiMap">
* {@code BiMap}</a>.
*
* @author Mike Bostock
* @since 2.0 (imported from Google Collections Library)
*/
@GwtCompatible(emulated = true)
public final class EnumHashBiMap<K extends Enum<K>, V>
extends AbstractBiMap<K, V> {
private transient Class<K> keyType;
/**
* Returns a new, empty {@code EnumHashBiMap} using the specified key type.
*
* @param keyType the key type
*/
public static <K extends Enum<K>, V> EnumHashBiMap<K, V>
create(Class<K> keyType) {
return new EnumHashBiMap<K, V>(keyType);
}
/**
* Constructs a new bimap with the same mappings as the specified map. If the
* specified map is an {@code EnumHashBiMap} or an {@link EnumBiMap}, the new
* bimap has the same key type as the input bimap. Otherwise, the specified
* map must contain at least one mapping, in order to determine the key type.
*
* @param map the map whose mappings are to be placed in this map
* @throws IllegalArgumentException if map is not an {@code EnumBiMap} or an
* {@code EnumHashBiMap} instance and contains no mappings
*/
public static <K extends Enum<K>, V> EnumHashBiMap<K, V>
create(Map<K, ? extends V> map) {
EnumHashBiMap<K, V> bimap = create(EnumBiMap.inferKeyType(map));
bimap.putAll(map);
return bimap;
}
private EnumHashBiMap(Class<K> keyType) {
super(WellBehavedMap.wrap(
new EnumMap<K, V>(keyType)),
Maps.<V, K>newHashMapWithExpectedSize(
keyType.getEnumConstants().length));
this.keyType = keyType;
}
// Overriding these three methods to show that values may be null (but not keys)
@Override
K checkKey(K key) {
return checkNotNull(key);
}
@Override public V put(K key, @Nullable V value) {
return super.put(key, value);
}
@Override public V forcePut(K key, @Nullable V value) {
return super.forcePut(key, value);
}
/** Returns the associated key type. */
public Class<K> keyType() {
return keyType;
}
}
| Java |
/*
* Copyright (C) 2007 The Guava Authors
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package com.google.common.collect;
import static com.google.common.base.Preconditions.checkArgument;
import static com.google.common.base.Preconditions.checkNotNull;
import static com.google.common.base.Preconditions.checkState;
import com.google.common.annotations.Beta;
import com.google.common.annotations.GwtCompatible;
import com.google.common.base.Function;
import com.google.common.base.Joiner;
import com.google.common.base.Joiner.MapJoiner;
import com.google.common.base.Objects;
import com.google.common.base.Predicate;
import com.google.common.base.Predicates;
import com.google.common.base.Supplier;
import com.google.common.collect.Collections2.TransformedCollection;
import com.google.common.collect.Maps.EntryTransformer;
import java.io.Serializable;
import java.util.AbstractCollection;
import java.util.AbstractSet;
import java.util.Collection;
import java.util.Collections;
import java.util.Comparator;
import java.util.HashSet;
import java.util.Iterator;
import java.util.List;
import java.util.Map;
import java.util.Map.Entry;
import java.util.NoSuchElementException;
import java.util.Set;
import java.util.SortedSet;
import javax.annotation.Nullable;
/**
* Provides static methods acting on or generating a {@code Multimap}.
*
* <p>See the Guava User Guide article on <a href=
* "http://code.google.com/p/guava-libraries/wiki/CollectionUtilitiesExplained#Multimaps">
* {@code Multimaps}</a>.
*
* @author Jared Levy
* @author Robert Konigsberg
* @author Mike Bostock
* @author Louis Wasserman
* @since 2.0 (imported from Google Collections Library)
*/
@GwtCompatible(emulated = true)
public final class Multimaps {
private Multimaps() {}
/**
* Creates a new {@code Multimap} that uses the provided map and factory. It
* can generate a multimap based on arbitrary {@link Map} and
* {@link Collection} classes.
*
* <p>The {@code factory}-generated and {@code map} classes determine the
* multimap iteration order. They also specify the behavior of the
* {@code equals}, {@code hashCode}, and {@code toString} methods for the
* multimap and its returned views. However, the multimap's {@code get}
* method returns instances of a different class than {@code factory.get()}
* does.
*
* <p>The multimap is serializable if {@code map}, {@code factory}, the
* collections generated by {@code factory}, and the multimap contents are all
* serializable.
*
* <p>The multimap is not threadsafe when any concurrent operations update the
* multimap, even if {@code map} and the instances generated by
* {@code factory} are. Concurrent read operations will work correctly. To
* allow concurrent update operations, wrap the multimap with a call to
* {@link #synchronizedMultimap}.
*
* <p>Call this method only when the simpler methods
* {@link ArrayListMultimap#create()}, {@link HashMultimap#create()},
* {@link LinkedHashMultimap#create()}, {@link LinkedListMultimap#create()},
* {@link TreeMultimap#create()}, and
* {@link TreeMultimap#create(Comparator, Comparator)} won't suffice.
*
* <p>Note: the multimap assumes complete ownership over of {@code map} and
* the collections returned by {@code factory}. Those objects should not be
* manually updated and they should not use soft, weak, or phantom references.
*
* @param map place to store the mapping from each key to its corresponding
* values
* @param factory supplier of new, empty collections that will each hold all
* values for a given key
* @throws IllegalArgumentException if {@code map} is not empty
*/
public static <K, V> Multimap<K, V> newMultimap(Map<K, Collection<V>> map,
final Supplier<? extends Collection<V>> factory) {
return new CustomMultimap<K, V>(map, factory);
}
private static class CustomMultimap<K, V> extends AbstractMultimap<K, V> {
transient Supplier<? extends Collection<V>> factory;
CustomMultimap(Map<K, Collection<V>> map,
Supplier<? extends Collection<V>> factory) {
super(map);
this.factory = checkNotNull(factory);
}
@Override protected Collection<V> createCollection() {
return factory.get();
}
// can't use Serialization writeMultimap and populateMultimap methods since
// there's no way to generate the empty backing map.
}
/**
* Creates a new {@code ListMultimap} that uses the provided map and factory.
* It can generate a multimap based on arbitrary {@link Map} and {@link List}
* classes.
*
* <p>The {@code factory}-generated and {@code map} classes determine the
* multimap iteration order. They also specify the behavior of the
* {@code equals}, {@code hashCode}, and {@code toString} methods for the
* multimap and its returned views. The multimap's {@code get}, {@code
* removeAll}, and {@code replaceValues} methods return {@code RandomAccess}
* lists if the factory does. However, the multimap's {@code get} method
* returns instances of a different class than does {@code factory.get()}.
*
* <p>The multimap is serializable if {@code map}, {@code factory}, the
* lists generated by {@code factory}, and the multimap contents are all
* serializable.
*
* <p>The multimap is not threadsafe when any concurrent operations update the
* multimap, even if {@code map} and the instances generated by
* {@code factory} are. Concurrent read operations will work correctly. To
* allow concurrent update operations, wrap the multimap with a call to
* {@link #synchronizedListMultimap}.
*
* <p>Call this method only when the simpler methods
* {@link ArrayListMultimap#create()} and {@link LinkedListMultimap#create()}
* won't suffice.
*
* <p>Note: the multimap assumes complete ownership over of {@code map} and
* the lists returned by {@code factory}. Those objects should not be manually
* updated, they should be empty when provided, and they should not use soft,
* weak, or phantom references.
*
* @param map place to store the mapping from each key to its corresponding
* values
* @param factory supplier of new, empty lists that will each hold all values
* for a given key
* @throws IllegalArgumentException if {@code map} is not empty
*/
public static <K, V> ListMultimap<K, V> newListMultimap(
Map<K, Collection<V>> map, final Supplier<? extends List<V>> factory) {
return new CustomListMultimap<K, V>(map, factory);
}
private static class CustomListMultimap<K, V>
extends AbstractListMultimap<K, V> {
transient Supplier<? extends List<V>> factory;
CustomListMultimap(Map<K, Collection<V>> map,
Supplier<? extends List<V>> factory) {
super(map);
this.factory = checkNotNull(factory);
}
@Override protected List<V> createCollection() {
return factory.get();
}
}
/**
* Creates a new {@code SetMultimap} that uses the provided map and factory.
* It can generate a multimap based on arbitrary {@link Map} and {@link Set}
* classes.
*
* <p>The {@code factory}-generated and {@code map} classes determine the
* multimap iteration order. They also specify the behavior of the
* {@code equals}, {@code hashCode}, and {@code toString} methods for the
* multimap and its returned views. However, the multimap's {@code get}
* method returns instances of a different class than {@code factory.get()}
* does.
*
* <p>The multimap is serializable if {@code map}, {@code factory}, the
* sets generated by {@code factory}, and the multimap contents are all
* serializable.
*
* <p>The multimap is not threadsafe when any concurrent operations update the
* multimap, even if {@code map} and the instances generated by
* {@code factory} are. Concurrent read operations will work correctly. To
* allow concurrent update operations, wrap the multimap with a call to
* {@link #synchronizedSetMultimap}.
*
* <p>Call this method only when the simpler methods
* {@link HashMultimap#create()}, {@link LinkedHashMultimap#create()},
* {@link TreeMultimap#create()}, and
* {@link TreeMultimap#create(Comparator, Comparator)} won't suffice.
*
* <p>Note: the multimap assumes complete ownership over of {@code map} and
* the sets returned by {@code factory}. Those objects should not be manually
* updated and they should not use soft, weak, or phantom references.
*
* @param map place to store the mapping from each key to its corresponding
* values
* @param factory supplier of new, empty sets that will each hold all values
* for a given key
* @throws IllegalArgumentException if {@code map} is not empty
*/
public static <K, V> SetMultimap<K, V> newSetMultimap(
Map<K, Collection<V>> map, final Supplier<? extends Set<V>> factory) {
return new CustomSetMultimap<K, V>(map, factory);
}
private static class CustomSetMultimap<K, V>
extends AbstractSetMultimap<K, V> {
transient Supplier<? extends Set<V>> factory;
CustomSetMultimap(Map<K, Collection<V>> map,
Supplier<? extends Set<V>> factory) {
super(map);
this.factory = checkNotNull(factory);
}
@Override protected Set<V> createCollection() {
return factory.get();
}
}
/**
* Creates a new {@code SortedSetMultimap} that uses the provided map and
* factory. It can generate a multimap based on arbitrary {@link Map} and
* {@link SortedSet} classes.
*
* <p>The {@code factory}-generated and {@code map} classes determine the
* multimap iteration order. They also specify the behavior of the
* {@code equals}, {@code hashCode}, and {@code toString} methods for the
* multimap and its returned views. However, the multimap's {@code get}
* method returns instances of a different class than {@code factory.get()}
* does.
*
* <p>The multimap is serializable if {@code map}, {@code factory}, the
* sets generated by {@code factory}, and the multimap contents are all
* serializable.
*
* <p>The multimap is not threadsafe when any concurrent operations update the
* multimap, even if {@code map} and the instances generated by
* {@code factory} are. Concurrent read operations will work correctly. To
* allow concurrent update operations, wrap the multimap with a call to
* {@link #synchronizedSortedSetMultimap}.
*
* <p>Call this method only when the simpler methods
* {@link TreeMultimap#create()} and
* {@link TreeMultimap#create(Comparator, Comparator)} won't suffice.
*
* <p>Note: the multimap assumes complete ownership over of {@code map} and
* the sets returned by {@code factory}. Those objects should not be manually
* updated and they should not use soft, weak, or phantom references.
*
* @param map place to store the mapping from each key to its corresponding
* values
* @param factory supplier of new, empty sorted sets that will each hold
* all values for a given key
* @throws IllegalArgumentException if {@code map} is not empty
*/
public static <K, V> SortedSetMultimap<K, V> newSortedSetMultimap(
Map<K, Collection<V>> map,
final Supplier<? extends SortedSet<V>> factory) {
return new CustomSortedSetMultimap<K, V>(map, factory);
}
private static class CustomSortedSetMultimap<K, V>
extends AbstractSortedSetMultimap<K, V> {
transient Supplier<? extends SortedSet<V>> factory;
transient Comparator<? super V> valueComparator;
CustomSortedSetMultimap(Map<K, Collection<V>> map,
Supplier<? extends SortedSet<V>> factory) {
super(map);
this.factory = checkNotNull(factory);
valueComparator = factory.get().comparator();
}
@Override protected SortedSet<V> createCollection() {
return factory.get();
}
@Override public Comparator<? super V> valueComparator() {
return valueComparator;
}
}
/**
* Copies each key-value mapping in {@code source} into {@code dest}, with
* its key and value reversed.
*
* <p>If {@code source} is an {@link ImmutableMultimap}, consider using
* {@link ImmutableMultimap#inverse} instead.
*
* @param source any multimap
* @param dest the multimap to copy into; usually empty
* @return {@code dest}
*/
public static <K, V, M extends Multimap<K, V>> M invertFrom(
Multimap<? extends V, ? extends K> source, M dest) {
checkNotNull(dest);
for (Map.Entry<? extends V, ? extends K> entry : source.entries()) {
dest.put(entry.getValue(), entry.getKey());
}
return dest;
}
/**
* Returns a synchronized (thread-safe) multimap backed by the specified
* multimap. In order to guarantee serial access, it is critical that
* <b>all</b> access to the backing multimap is accomplished through the
* returned multimap.
*
* <p>It is imperative that the user manually synchronize on the returned
* multimap when accessing any of its collection views: <pre> {@code
*
* Multimap<K, V> m = Multimaps.synchronizedMultimap(
* HashMultimap.<K, V>create());
* ...
* Set<K> s = m.keySet(); // Needn't be in synchronized block
* ...
* synchronized (m) { // Synchronizing on m, not s!
* Iterator<K> i = s.iterator(); // Must be in synchronized block
* while (i.hasNext()) {
* foo(i.next());
* }
* }}</pre>
*
* Failure to follow this advice may result in non-deterministic behavior.
*
* <p>Note that the generated multimap's {@link Multimap#removeAll} and
* {@link Multimap#replaceValues} methods return collections that aren't
* synchronized.
*
* <p>The returned multimap will be serializable if the specified multimap is
* serializable.
*
* @param multimap the multimap to be wrapped in a synchronized view
* @return a synchronized view of the specified multimap
*/
public static <K, V> Multimap<K, V> synchronizedMultimap(
Multimap<K, V> multimap) {
return Synchronized.multimap(multimap, null);
}
/**
* Returns an unmodifiable view of the specified multimap. Query operations on
* the returned multimap "read through" to the specified multimap, and
* attempts to modify the returned multimap, either directly or through the
* multimap's views, result in an {@code UnsupportedOperationException}.
*
* <p>Note that the generated multimap's {@link Multimap#removeAll} and
* {@link Multimap#replaceValues} methods return collections that are
* modifiable.
*
* <p>The returned multimap will be serializable if the specified multimap is
* serializable.
*
* @param delegate the multimap for which an unmodifiable view is to be
* returned
* @return an unmodifiable view of the specified multimap
*/
public static <K, V> Multimap<K, V> unmodifiableMultimap(
Multimap<K, V> delegate) {
if (delegate instanceof UnmodifiableMultimap ||
delegate instanceof ImmutableMultimap) {
return delegate;
}
return new UnmodifiableMultimap<K, V>(delegate);
}
/**
* Simply returns its argument.
*
* @deprecated no need to use this
* @since 10.0
*/
@Deprecated public static <K, V> Multimap<K, V> unmodifiableMultimap(
ImmutableMultimap<K, V> delegate) {
return checkNotNull(delegate);
}
private static class UnmodifiableMultimap<K, V>
extends ForwardingMultimap<K, V> implements Serializable {
final Multimap<K, V> delegate;
transient Collection<Entry<K, V>> entries;
transient Multiset<K> keys;
transient Set<K> keySet;
transient Collection<V> values;
transient Map<K, Collection<V>> map;
UnmodifiableMultimap(final Multimap<K, V> delegate) {
this.delegate = checkNotNull(delegate);
}
@Override protected Multimap<K, V> delegate() {
return delegate;
}
@Override public void clear() {
throw new UnsupportedOperationException();
}
@Override public Map<K, Collection<V>> asMap() {
Map<K, Collection<V>> result = map;
if (result == null) {
final Map<K, Collection<V>> unmodifiableMap
= Collections.unmodifiableMap(delegate.asMap());
map = result = new ForwardingMap<K, Collection<V>>() {
@Override protected Map<K, Collection<V>> delegate() {
return unmodifiableMap;
}
Set<Entry<K, Collection<V>>> entrySet;
@Override public Set<Map.Entry<K, Collection<V>>> entrySet() {
Set<Entry<K, Collection<V>>> result = entrySet;
return (result == null)
? entrySet
= unmodifiableAsMapEntries(unmodifiableMap.entrySet())
: result;
}
@Override public Collection<V> get(Object key) {
Collection<V> collection = unmodifiableMap.get(key);
return (collection == null)
? null : unmodifiableValueCollection(collection);
}
Collection<Collection<V>> asMapValues;
@Override public Collection<Collection<V>> values() {
Collection<Collection<V>> result = asMapValues;
return (result == null)
? asMapValues
= new UnmodifiableAsMapValues<V>(unmodifiableMap.values())
: result;
}
@Override public boolean containsValue(Object o) {
return values().contains(o);
}
};
}
return result;
}
@Override public Collection<Entry<K, V>> entries() {
Collection<Entry<K, V>> result = entries;
if (result == null) {
entries = result = unmodifiableEntries(delegate.entries());
}
return result;
}
@Override public Collection<V> get(K key) {
return unmodifiableValueCollection(delegate.get(key));
}
@Override public Multiset<K> keys() {
Multiset<K> result = keys;
if (result == null) {
keys = result = Multisets.unmodifiableMultiset(delegate.keys());
}
return result;
}
@Override public Set<K> keySet() {
Set<K> result = keySet;
if (result == null) {
keySet = result = Collections.unmodifiableSet(delegate.keySet());
}
return result;
}
@Override public boolean put(K key, V value) {
throw new UnsupportedOperationException();
}
@Override public boolean putAll(K key, Iterable<? extends V> values) {
throw new UnsupportedOperationException();
}
@Override
public boolean putAll(Multimap<? extends K, ? extends V> multimap) {
throw new UnsupportedOperationException();
}
@Override public boolean remove(Object key, Object value) {
throw new UnsupportedOperationException();
}
@Override public Collection<V> removeAll(Object key) {
throw new UnsupportedOperationException();
}
@Override public Collection<V> replaceValues(
K key, Iterable<? extends V> values) {
throw new UnsupportedOperationException();
}
@Override public Collection<V> values() {
Collection<V> result = values;
if (result == null) {
values = result = Collections.unmodifiableCollection(delegate.values());
}
return result;
}
private static final long serialVersionUID = 0;
}
private static class UnmodifiableAsMapValues<V>
extends ForwardingCollection<Collection<V>> {
final Collection<Collection<V>> delegate;
UnmodifiableAsMapValues(Collection<Collection<V>> delegate) {
this.delegate = Collections.unmodifiableCollection(delegate);
}
@Override protected Collection<Collection<V>> delegate() {
return delegate;
}
@Override public Iterator<Collection<V>> iterator() {
final Iterator<Collection<V>> iterator = delegate.iterator();
return new Iterator<Collection<V>>() {
@Override
public boolean hasNext() {
return iterator.hasNext();
}
@Override
public Collection<V> next() {
return unmodifiableValueCollection(iterator.next());
}
@Override
public void remove() {
throw new UnsupportedOperationException();
}
};
}
@Override public Object[] toArray() {
return standardToArray();
}
@Override public <T> T[] toArray(T[] array) {
return standardToArray(array);
}
@Override public boolean contains(Object o) {
return standardContains(o);
}
@Override public boolean containsAll(Collection<?> c) {
return standardContainsAll(c);
}
}
private static class UnmodifiableListMultimap<K, V>
extends UnmodifiableMultimap<K, V> implements ListMultimap<K, V> {
UnmodifiableListMultimap(ListMultimap<K, V> delegate) {
super(delegate);
}
@Override public ListMultimap<K, V> delegate() {
return (ListMultimap<K, V>) super.delegate();
}
@Override public List<V> get(K key) {
return Collections.unmodifiableList(delegate().get(key));
}
@Override public List<V> removeAll(Object key) {
throw new UnsupportedOperationException();
}
@Override public List<V> replaceValues(
K key, Iterable<? extends V> values) {
throw new UnsupportedOperationException();
}
private static final long serialVersionUID = 0;
}
private static class UnmodifiableSetMultimap<K, V>
extends UnmodifiableMultimap<K, V> implements SetMultimap<K, V> {
UnmodifiableSetMultimap(SetMultimap<K, V> delegate) {
super(delegate);
}
@Override public SetMultimap<K, V> delegate() {
return (SetMultimap<K, V>) super.delegate();
}
@Override public Set<V> get(K key) {
/*
* Note that this doesn't return a SortedSet when delegate is a
* SortedSetMultiset, unlike (SortedSet<V>) super.get().
*/
return Collections.unmodifiableSet(delegate().get(key));
}
@Override public Set<Map.Entry<K, V>> entries() {
return Maps.unmodifiableEntrySet(delegate().entries());
}
@Override public Set<V> removeAll(Object key) {
throw new UnsupportedOperationException();
}
@Override public Set<V> replaceValues(
K key, Iterable<? extends V> values) {
throw new UnsupportedOperationException();
}
private static final long serialVersionUID = 0;
}
private static class UnmodifiableSortedSetMultimap<K, V>
extends UnmodifiableSetMultimap<K, V> implements SortedSetMultimap<K, V> {
UnmodifiableSortedSetMultimap(SortedSetMultimap<K, V> delegate) {
super(delegate);
}
@Override public SortedSetMultimap<K, V> delegate() {
return (SortedSetMultimap<K, V>) super.delegate();
}
@Override public SortedSet<V> get(K key) {
return Collections.unmodifiableSortedSet(delegate().get(key));
}
@Override public SortedSet<V> removeAll(Object key) {
throw new UnsupportedOperationException();
}
@Override public SortedSet<V> replaceValues(
K key, Iterable<? extends V> values) {
throw new UnsupportedOperationException();
}
@Override
public Comparator<? super V> valueComparator() {
return delegate().valueComparator();
}
private static final long serialVersionUID = 0;
}
/**
* Returns a synchronized (thread-safe) {@code SetMultimap} backed by the
* specified multimap.
*
* <p>You must follow the warnings described in {@link #synchronizedMultimap}.
*
* <p>The returned multimap will be serializable if the specified multimap is
* serializable.
*
* @param multimap the multimap to be wrapped
* @return a synchronized view of the specified multimap
*/
public static <K, V> SetMultimap<K, V> synchronizedSetMultimap(
SetMultimap<K, V> multimap) {
return Synchronized.setMultimap(multimap, null);
}
/**
* Returns an unmodifiable view of the specified {@code SetMultimap}. Query
* operations on the returned multimap "read through" to the specified
* multimap, and attempts to modify the returned multimap, either directly or
* through the multimap's views, result in an
* {@code UnsupportedOperationException}.
*
* <p>Note that the generated multimap's {@link Multimap#removeAll} and
* {@link Multimap#replaceValues} methods return collections that are
* modifiable.
*
* <p>The returned multimap will be serializable if the specified multimap is
* serializable.
*
* @param delegate the multimap for which an unmodifiable view is to be
* returned
* @return an unmodifiable view of the specified multimap
*/
public static <K, V> SetMultimap<K, V> unmodifiableSetMultimap(
SetMultimap<K, V> delegate) {
if (delegate instanceof UnmodifiableSetMultimap ||
delegate instanceof ImmutableSetMultimap) {
return delegate;
}
return new UnmodifiableSetMultimap<K, V>(delegate);
}
/**
* Simply returns its argument.
*
* @deprecated no need to use this
* @since 10.0
*/
@Deprecated public static <K, V> SetMultimap<K, V> unmodifiableSetMultimap(
ImmutableSetMultimap<K, V> delegate) {
return checkNotNull(delegate);
}
/**
* Returns a synchronized (thread-safe) {@code SortedSetMultimap} backed by
* the specified multimap.
*
* <p>You must follow the warnings described in {@link #synchronizedMultimap}.
*
* <p>The returned multimap will be serializable if the specified multimap is
* serializable.
*
* @param multimap the multimap to be wrapped
* @return a synchronized view of the specified multimap
*/
public static <K, V> SortedSetMultimap<K, V>
synchronizedSortedSetMultimap(SortedSetMultimap<K, V> multimap) {
return Synchronized.sortedSetMultimap(multimap, null);
}
/**
* Returns an unmodifiable view of the specified {@code SortedSetMultimap}.
* Query operations on the returned multimap "read through" to the specified
* multimap, and attempts to modify the returned multimap, either directly or
* through the multimap's views, result in an
* {@code UnsupportedOperationException}.
*
* <p>Note that the generated multimap's {@link Multimap#removeAll} and
* {@link Multimap#replaceValues} methods return collections that are
* modifiable.
*
* <p>The returned multimap will be serializable if the specified multimap is
* serializable.
*
* @param delegate the multimap for which an unmodifiable view is to be
* returned
* @return an unmodifiable view of the specified multimap
*/
public static <K, V> SortedSetMultimap<K, V> unmodifiableSortedSetMultimap(
SortedSetMultimap<K, V> delegate) {
if (delegate instanceof UnmodifiableSortedSetMultimap) {
return delegate;
}
return new UnmodifiableSortedSetMultimap<K, V>(delegate);
}
/**
* Returns a synchronized (thread-safe) {@code ListMultimap} backed by the
* specified multimap.
*
* <p>You must follow the warnings described in {@link #synchronizedMultimap}.
*
* @param multimap the multimap to be wrapped
* @return a synchronized view of the specified multimap
*/
public static <K, V> ListMultimap<K, V> synchronizedListMultimap(
ListMultimap<K, V> multimap) {
return Synchronized.listMultimap(multimap, null);
}
/**
* Returns an unmodifiable view of the specified {@code ListMultimap}. Query
* operations on the returned multimap "read through" to the specified
* multimap, and attempts to modify the returned multimap, either directly or
* through the multimap's views, result in an
* {@code UnsupportedOperationException}.
*
* <p>Note that the generated multimap's {@link Multimap#removeAll} and
* {@link Multimap#replaceValues} methods return collections that are
* modifiable.
*
* <p>The returned multimap will be serializable if the specified multimap is
* serializable.
*
* @param delegate the multimap for which an unmodifiable view is to be
* returned
* @return an unmodifiable view of the specified multimap
*/
public static <K, V> ListMultimap<K, V> unmodifiableListMultimap(
ListMultimap<K, V> delegate) {
if (delegate instanceof UnmodifiableListMultimap ||
delegate instanceof ImmutableListMultimap) {
return delegate;
}
return new UnmodifiableListMultimap<K, V>(delegate);
}
/**
* Simply returns its argument.
*
* @deprecated no need to use this
* @since 10.0
*/
@Deprecated public static <K, V> ListMultimap<K, V> unmodifiableListMultimap(
ImmutableListMultimap<K, V> delegate) {
return checkNotNull(delegate);
}
/**
* Returns an unmodifiable view of the specified collection, preserving the
* interface for instances of {@code SortedSet}, {@code Set}, {@code List} and
* {@code Collection}, in that order of preference.
*
* @param collection the collection for which to return an unmodifiable view
* @return an unmodifiable view of the collection
*/
private static <V> Collection<V> unmodifiableValueCollection(
Collection<V> collection) {
if (collection instanceof SortedSet) {
return Collections.unmodifiableSortedSet((SortedSet<V>) collection);
} else if (collection instanceof Set) {
return Collections.unmodifiableSet((Set<V>) collection);
} else if (collection instanceof List) {
return Collections.unmodifiableList((List<V>) collection);
}
return Collections.unmodifiableCollection(collection);
}
/**
* Returns an unmodifiable view of the specified multimap {@code asMap} entry.
* The {@link Entry#setValue} operation throws an {@link
* UnsupportedOperationException}, and the collection returned by {@code
* getValue} is also an unmodifiable (type-preserving) view. This also has the
* side-effect of redefining equals to comply with the Map.Entry contract, and
* to avoid a possible nefarious implementation of equals.
*
* @param entry the entry for which to return an unmodifiable view
* @return an unmodifiable view of the entry
*/
private static <K, V> Map.Entry<K, Collection<V>> unmodifiableAsMapEntry(
final Map.Entry<K, Collection<V>> entry) {
checkNotNull(entry);
return new AbstractMapEntry<K, Collection<V>>() {
@Override public K getKey() {
return entry.getKey();
}
@Override public Collection<V> getValue() {
return unmodifiableValueCollection(entry.getValue());
}
};
}
/**
* Returns an unmodifiable view of the specified collection of entries. The
* {@link Entry#setValue} operation throws an {@link
* UnsupportedOperationException}. If the specified collection is a {@code
* Set}, the returned collection is also a {@code Set}.
*
* @param entries the entries for which to return an unmodifiable view
* @return an unmodifiable view of the entries
*/
private static <K, V> Collection<Entry<K, V>> unmodifiableEntries(
Collection<Entry<K, V>> entries) {
if (entries instanceof Set) {
return Maps.unmodifiableEntrySet((Set<Entry<K, V>>) entries);
}
return new Maps.UnmodifiableEntries<K, V>(
Collections.unmodifiableCollection(entries));
}
/**
* Returns an unmodifiable view of the specified set of {@code asMap} entries.
* The {@link Entry#setValue} operation throws an {@link
* UnsupportedOperationException}, as do any operations that attempt to modify
* the returned collection.
*
* @param asMapEntries the {@code asMap} entries for which to return an
* unmodifiable view
* @return an unmodifiable view of the collection entries
*/
private static <K, V> Set<Entry<K, Collection<V>>> unmodifiableAsMapEntries(
Set<Entry<K, Collection<V>>> asMapEntries) {
return new UnmodifiableAsMapEntries<K, V>(
Collections.unmodifiableSet(asMapEntries));
}
/** @see Multimaps#unmodifiableAsMapEntries */
static class UnmodifiableAsMapEntries<K, V>
extends ForwardingSet<Entry<K, Collection<V>>> {
private final Set<Entry<K, Collection<V>>> delegate;
UnmodifiableAsMapEntries(Set<Entry<K, Collection<V>>> delegate) {
this.delegate = delegate;
}
@Override protected Set<Entry<K, Collection<V>>> delegate() {
return delegate;
}
@Override public Iterator<Entry<K, Collection<V>>> iterator() {
final Iterator<Entry<K, Collection<V>>> iterator = delegate.iterator();
return new ForwardingIterator<Entry<K, Collection<V>>>() {
@Override protected Iterator<Entry<K, Collection<V>>> delegate() {
return iterator;
}
@Override public Entry<K, Collection<V>> next() {
return unmodifiableAsMapEntry(iterator.next());
}
};
}
@Override public Object[] toArray() {
return standardToArray();
}
@Override public <T> T[] toArray(T[] array) {
return standardToArray(array);
}
@Override public boolean contains(Object o) {
return Maps.containsEntryImpl(delegate(), o);
}
@Override public boolean containsAll(Collection<?> c) {
return standardContainsAll(c);
}
@Override public boolean equals(@Nullable Object object) {
return standardEquals(object);
}
}
/**
* Returns a multimap view of the specified map. The multimap is backed by the
* map, so changes to the map are reflected in the multimap, and vice versa.
* If the map is modified while an iteration over one of the multimap's
* collection views is in progress (except through the iterator's own {@code
* remove} operation, or through the {@code setValue} operation on a map entry
* returned by the iterator), the results of the iteration are undefined.
*
* <p>The multimap supports mapping removal, which removes the corresponding
* mapping from the map. It does not support any operations which might add
* mappings, such as {@code put}, {@code putAll} or {@code replaceValues}.
*
* <p>The returned multimap will be serializable if the specified map is
* serializable.
*
* @param map the backing map for the returned multimap view
*/
public static <K, V> SetMultimap<K, V> forMap(Map<K, V> map) {
return new MapMultimap<K, V>(map);
}
/** @see Multimaps#forMap */
private static class MapMultimap<K, V>
implements SetMultimap<K, V>, Serializable {
final Map<K, V> map;
transient Map<K, Collection<V>> asMap;
MapMultimap(Map<K, V> map) {
this.map = checkNotNull(map);
}
@Override
public int size() {
return map.size();
}
@Override
public boolean isEmpty() {
return map.isEmpty();
}
@Override
public boolean containsKey(Object key) {
return map.containsKey(key);
}
@Override
public boolean containsValue(Object value) {
return map.containsValue(value);
}
@Override
public boolean containsEntry(Object key, Object value) {
return map.entrySet().contains(Maps.immutableEntry(key, value));
}
@Override
public Set<V> get(final K key) {
return new AbstractSet<V>() {
@Override public Iterator<V> iterator() {
return new Iterator<V>() {
int i;
@Override
public boolean hasNext() {
return (i == 0) && map.containsKey(key);
}
@Override
public V next() {
if (!hasNext()) {
throw new NoSuchElementException();
}
i++;
return map.get(key);
}
@Override
public void remove() {
checkState(i == 1);
i = -1;
map.remove(key);
}
};
}
@Override public int size() {
return map.containsKey(key) ? 1 : 0;
}
};
}
@Override
public boolean put(K key, V value) {
throw new UnsupportedOperationException();
}
@Override
public boolean putAll(K key, Iterable<? extends V> values) {
throw new UnsupportedOperationException();
}
@Override
public boolean putAll(Multimap<? extends K, ? extends V> multimap) {
throw new UnsupportedOperationException();
}
@Override
public Set<V> replaceValues(K key, Iterable<? extends V> values) {
throw new UnsupportedOperationException();
}
@Override
public boolean remove(Object key, Object value) {
return map.entrySet().remove(Maps.immutableEntry(key, value));
}
@Override
public Set<V> removeAll(Object key) {
Set<V> values = new HashSet<V>(2);
if (!map.containsKey(key)) {
return values;
}
values.add(map.remove(key));
return values;
}
@Override
public void clear() {
map.clear();
}
@Override
public Set<K> keySet() {
return map.keySet();
}
@Override
public Multiset<K> keys() {
return Multisets.forSet(map.keySet());
}
@Override
public Collection<V> values() {
return map.values();
}
@Override
public Set<Entry<K, V>> entries() {
return map.entrySet();
}
@Override
public Map<K, Collection<V>> asMap() {
Map<K, Collection<V>> result = asMap;
if (result == null) {
asMap = result = new AsMap();
}
return result;
}
@Override public boolean equals(@Nullable Object object) {
if (object == this) {
return true;
}
if (object instanceof Multimap) {
Multimap<?, ?> that = (Multimap<?, ?>) object;
return this.size() == that.size() && asMap().equals(that.asMap());
}
return false;
}
@Override public int hashCode() {
return map.hashCode();
}
private static final MapJoiner JOINER
= Joiner.on("], ").withKeyValueSeparator("=[").useForNull("null");
@Override public String toString() {
if (map.isEmpty()) {
return "{}";
}
StringBuilder builder
= Collections2.newStringBuilderForCollection(map.size()).append('{');
JOINER.appendTo(builder, map);
return builder.append("]}").toString();
}
/** @see MapMultimap#asMap */
class AsMapEntries extends AbstractSet<Entry<K, Collection<V>>> {
@Override public int size() {
return map.size();
}
@Override public Iterator<Entry<K, Collection<V>>> iterator() {
return new Iterator<Entry<K, Collection<V>>>() {
final Iterator<K> keys = map.keySet().iterator();
@Override
public boolean hasNext() {
return keys.hasNext();
}
@Override
public Entry<K, Collection<V>> next() {
final K key = keys.next();
return new AbstractMapEntry<K, Collection<V>>() {
@Override public K getKey() {
return key;
}
@Override public Collection<V> getValue() {
return get(key);
}
};
}
@Override
public void remove() {
keys.remove();
}
};
}
@Override public boolean contains(Object o) {
if (!(o instanceof Entry)) {
return false;
}
Entry<?, ?> entry = (Entry<?, ?>) o;
if (!(entry.getValue() instanceof Set)) {
return false;
}
Set<?> set = (Set<?>) entry.getValue();
return (set.size() == 1)
&& containsEntry(entry.getKey(), set.iterator().next());
}
@Override public boolean remove(Object o) {
if (!(o instanceof Entry)) {
return false;
}
Entry<?, ?> entry = (Entry<?, ?>) o;
if (!(entry.getValue() instanceof Set)) {
return false;
}
Set<?> set = (Set<?>) entry.getValue();
return (set.size() == 1)
&& map.entrySet().remove(
Maps.immutableEntry(entry.getKey(), set.iterator().next()));
}
}
/** @see MapMultimap#asMap */
class AsMap extends Maps.ImprovedAbstractMap<K, Collection<V>> {
@Override protected Set<Entry<K, Collection<V>>> createEntrySet() {
return new AsMapEntries();
}
// The following methods are included for performance.
@Override public boolean containsKey(Object key) {
return map.containsKey(key);
}
@SuppressWarnings("unchecked")
@Override public Collection<V> get(Object key) {
Collection<V> collection = MapMultimap.this.get((K) key);
return collection.isEmpty() ? null : collection;
}
@Override public Collection<V> remove(Object key) {
Collection<V> collection = removeAll(key);
return collection.isEmpty() ? null : collection;
}
}
private static final long serialVersionUID = 7845222491160860175L;
}
/**
* Returns a view of a multimap where each value is transformed by a function.
* All other properties of the multimap, such as iteration order, are left
* intact. For example, the code: <pre> {@code
*
* Multimap<String, Integer> multimap =
* ImmutableSetMultimap.of("a", 2, "b", -3, "b", -3, "a", 4, "c", 6);
* Function<Integer, String> square = new Function<Integer, String>() {
* public String apply(Integer in) {
* return Integer.toString(in * in);
* }
* };
* Multimap<String, String> transformed =
* Multimaps.transformValues(multimap, square);
* System.out.println(transformed);}</pre>
*
* ... prints {@code {a=[4, 16], b=[9, 9], c=[6]}}.
*
* <p>Changes in the underlying multimap are reflected in this view.
* Conversely, this view supports removal operations, and these are reflected
* in the underlying multimap.
*
* <p>It's acceptable for the underlying multimap to contain null keys, and
* even null values provided that the function is capable of accepting null
* input. The transformed multimap might contain null values, if the function
* sometimes gives a null result.
*
* <p>The returned multimap is not thread-safe or serializable, even if the
* underlying multimap is. The {@code equals} and {@code hashCode} methods
* of the returned multimap are meaningless, since there is not a definition
* of {@code equals} or {@code hashCode} for general collections, and
* {@code get()} will return a general {@code Collection} as opposed to a
* {@code List} or a {@code Set}.
*
* <p>The function is applied lazily, invoked when needed. This is necessary
* for the returned multimap to be a view, but it means that the function will
* be applied many times for bulk operations like
* {@link Multimap#containsValue} and {@code Multimap.toString()}. For this to
* perform well, {@code function} should be fast. To avoid lazy evaluation
* when the returned multimap doesn't need to be a view, copy the returned
* multimap into a new multimap of your choosing.
*
* @since 7.0
*/
@Beta
public static <K, V1, V2> Multimap<K, V2> transformValues(
Multimap<K, V1> fromMultimap, final Function<? super V1, V2> function) {
checkNotNull(function);
EntryTransformer<K, V1, V2> transformer =
new EntryTransformer<K, V1, V2>() {
@Override
public V2 transformEntry(K key, V1 value) {
return function.apply(value);
}
};
return transformEntries(fromMultimap, transformer);
}
/**
* Returns a view of a multimap whose values are derived from the original
* multimap's entries. In contrast to {@link #transformValues}, this method's
* entry-transformation logic may depend on the key as well as the value.
*
* <p>All other properties of the transformed multimap, such as iteration
* order, are left intact. For example, the code: <pre> {@code
*
* SetMultimap<String, Integer> multimap =
* ImmutableSetMultimap.of("a", 1, "a", 4, "b", -6);
* EntryTransformer<String, Integer, String> transformer =
* new EntryTransformer<String, Integer, String>() {
* public String transformEntry(String key, Integer value) {
* return (value >= 0) ? key : "no" + key;
* }
* };
* Multimap<String, String> transformed =
* Multimaps.transformEntries(multimap, transformer);
* System.out.println(transformed);}</pre>
*
* ... prints {@code {a=[a, a], b=[nob]}}.
*
* <p>Changes in the underlying multimap are reflected in this view.
* Conversely, this view supports removal operations, and these are reflected
* in the underlying multimap.
*
* <p>It's acceptable for the underlying multimap to contain null keys and
* null values provided that the transformer is capable of accepting null
* inputs. The transformed multimap might contain null values if the
* transformer sometimes gives a null result.
*
* <p>The returned multimap is not thread-safe or serializable, even if the
* underlying multimap is. The {@code equals} and {@code hashCode} methods
* of the returned multimap are meaningless, since there is not a definition
* of {@code equals} or {@code hashCode} for general collections, and
* {@code get()} will return a general {@code Collection} as opposed to a
* {@code List} or a {@code Set}.
*
* <p>The transformer is applied lazily, invoked when needed. This is
* necessary for the returned multimap to be a view, but it means that the
* transformer will be applied many times for bulk operations like {@link
* Multimap#containsValue} and {@link Object#toString}. For this to perform
* well, {@code transformer} should be fast. To avoid lazy evaluation when the
* returned multimap doesn't need to be a view, copy the returned multimap
* into a new multimap of your choosing.
*
* <p><b>Warning:</b> This method assumes that for any instance {@code k} of
* {@code EntryTransformer} key type {@code K}, {@code k.equals(k2)} implies
* that {@code k2} is also of type {@code K}. Using an {@code
* EntryTransformer} key type for which this may not hold, such as {@code
* ArrayList}, may risk a {@code ClassCastException} when calling methods on
* the transformed multimap.
*
* @since 7.0
*/
@Beta
public static <K, V1, V2> Multimap<K, V2> transformEntries(
Multimap<K, V1> fromMap,
EntryTransformer<? super K, ? super V1, V2> transformer) {
return new TransformedEntriesMultimap<K, V1, V2>(fromMap, transformer);
}
private static class TransformedEntriesMultimap<K, V1, V2>
implements Multimap<K, V2> {
final Multimap<K, V1> fromMultimap;
final EntryTransformer<? super K, ? super V1, V2> transformer;
TransformedEntriesMultimap(Multimap<K, V1> fromMultimap,
final EntryTransformer<? super K, ? super V1, V2> transformer) {
this.fromMultimap = checkNotNull(fromMultimap);
this.transformer = checkNotNull(transformer);
}
Collection<V2> transform(final K key, Collection<V1> values) {
return Collections2.transform(values, new Function<V1, V2>() {
@Override public V2 apply(V1 value) {
return transformer.transformEntry(key, value);
}
});
}
private transient Map<K, Collection<V2>> asMap;
@Override public Map<K, Collection<V2>> asMap() {
if (asMap == null) {
Map<K, Collection<V2>> aM = Maps.transformEntries(fromMultimap.asMap(),
new EntryTransformer<K, Collection<V1>, Collection<V2>>() {
@Override public Collection<V2> transformEntry(
K key, Collection<V1> value) {
return transform(key, value);
}
});
asMap = aM;
return aM;
}
return asMap;
}
@Override public void clear() {
fromMultimap.clear();
}
@SuppressWarnings("unchecked")
@Override public boolean containsEntry(Object key, Object value) {
Collection<V2> values = get((K) key);
return values.contains(value);
}
@Override public boolean containsKey(Object key) {
return fromMultimap.containsKey(key);
}
@Override public boolean containsValue(Object value) {
return values().contains(value);
}
private transient Collection<Entry<K, V2>> entries;
@Override public Collection<Entry<K, V2>> entries() {
if (entries == null) {
Collection<Entry<K, V2>> es = new TransformedEntries(transformer);
entries = es;
return es;
}
return entries;
}
private class TransformedEntries
extends TransformedCollection<Entry<K, V1>, Entry<K, V2>> {
TransformedEntries(
final EntryTransformer<? super K, ? super V1, V2> transformer) {
super(fromMultimap.entries(),
new Function<Entry<K, V1>, Entry<K, V2>>() {
@Override public Entry<K, V2> apply(final Entry<K, V1> entry) {
return new AbstractMapEntry<K, V2>() {
@Override public K getKey() {
return entry.getKey();
}
@Override public V2 getValue() {
return transformer.transformEntry(
entry.getKey(), entry.getValue());
}
};
}
});
}
@Override public boolean contains(Object o) {
if (o instanceof Entry) {
Entry<?, ?> entry = (Entry<?, ?>) o;
return containsEntry(entry.getKey(), entry.getValue());
}
return false;
}
@SuppressWarnings("unchecked")
@Override public boolean remove(Object o) {
if (o instanceof Entry) {
Entry<?, ?> entry = (Entry<?, ?>) o;
Collection<V2> values = get((K) entry.getKey());
return values.remove(entry.getValue());
}
return false;
}
}
@Override public Collection<V2> get(final K key) {
return transform(key, fromMultimap.get(key));
}
@Override public boolean isEmpty() {
return fromMultimap.isEmpty();
}
@Override public Set<K> keySet() {
return fromMultimap.keySet();
}
@Override public Multiset<K> keys() {
return fromMultimap.keys();
}
@Override public boolean put(K key, V2 value) {
throw new UnsupportedOperationException();
}
@Override public boolean putAll(K key, Iterable<? extends V2> values) {
throw new UnsupportedOperationException();
}
@Override public boolean putAll(
Multimap<? extends K, ? extends V2> multimap) {
throw new UnsupportedOperationException();
}
@SuppressWarnings("unchecked")
@Override public boolean remove(Object key, Object value) {
return get((K) key).remove(value);
}
@SuppressWarnings("unchecked")
@Override public Collection<V2> removeAll(Object key) {
return transform((K) key, fromMultimap.removeAll(key));
}
@Override public Collection<V2> replaceValues(
K key, Iterable<? extends V2> values) {
throw new UnsupportedOperationException();
}
@Override public int size() {
return fromMultimap.size();
}
private transient Collection<V2> values;
@Override public Collection<V2> values() {
if (values == null) {
Collection<V2> vs = Collections2.transform(
fromMultimap.entries(), new Function<Entry<K, V1>, V2>() {
@Override public V2 apply(Entry<K, V1> entry) {
return transformer.transformEntry(
entry.getKey(), entry.getValue());
}
});
values = vs;
return vs;
}
return values;
}
@Override public boolean equals(Object obj) {
if (obj instanceof Multimap) {
Multimap<?, ?> other = (Multimap<?, ?>) obj;
return asMap().equals(other.asMap());
}
return false;
}
@Override public int hashCode() {
return asMap().hashCode();
}
@Override public String toString() {
return asMap().toString();
}
}
/**
* Returns a view of a {@code ListMultimap} where each value is transformed by
* a function. All other properties of the multimap, such as iteration order,
* are left intact. For example, the code: <pre> {@code
*
* ListMultimap<String, Integer> multimap
* = ImmutableListMultimap.of("a", 4, "a", 16, "b", 9);
* Function<Integer, Double> sqrt =
* new Function<Integer, Double>() {
* public Double apply(Integer in) {
* return Math.sqrt((int) in);
* }
* };
* ListMultimap<String, Double> transformed = Multimaps.transformValues(map,
* sqrt);
* System.out.println(transformed);}</pre>
*
* ... prints {@code {a=[2.0, 4.0], b=[3.0]}}.
*
* <p>Changes in the underlying multimap are reflected in this view.
* Conversely, this view supports removal operations, and these are reflected
* in the underlying multimap.
*
* <p>It's acceptable for the underlying multimap to contain null keys, and
* even null values provided that the function is capable of accepting null
* input. The transformed multimap might contain null values, if the function
* sometimes gives a null result.
*
* <p>The returned multimap is not thread-safe or serializable, even if the
* underlying multimap is.
*
* <p>The function is applied lazily, invoked when needed. This is necessary
* for the returned multimap to be a view, but it means that the function will
* be applied many times for bulk operations like
* {@link Multimap#containsValue} and {@code Multimap.toString()}. For this to
* perform well, {@code function} should be fast. To avoid lazy evaluation
* when the returned multimap doesn't need to be a view, copy the returned
* multimap into a new multimap of your choosing.
*
* @since 7.0
*/
@Beta
public static <K, V1, V2> ListMultimap<K, V2> transformValues(
ListMultimap<K, V1> fromMultimap,
final Function<? super V1, V2> function) {
checkNotNull(function);
EntryTransformer<K, V1, V2> transformer =
new EntryTransformer<K, V1, V2>() {
@Override
public V2 transformEntry(K key, V1 value) {
return function.apply(value);
}
};
return transformEntries(fromMultimap, transformer);
}
/**
* Returns a view of a {@code ListMultimap} whose values are derived from the
* original multimap's entries. In contrast to
* {@link #transformValues(ListMultimap, Function)}, this method's
* entry-transformation logic may depend on the key as well as the value.
*
* <p>All other properties of the transformed multimap, such as iteration
* order, are left intact. For example, the code: <pre> {@code
*
* Multimap<String, Integer> multimap =
* ImmutableMultimap.of("a", 1, "a", 4, "b", 6);
* EntryTransformer<String, Integer, String> transformer =
* new EntryTransformer<String, Integer, String>() {
* public String transformEntry(String key, Integer value) {
* return key + value;
* }
* };
* Multimap<String, String> transformed =
* Multimaps.transformEntries(multimap, transformer);
* System.out.println(transformed);}</pre>
*
* ... prints {@code {"a"=["a1", "a4"], "b"=["b6"]}}.
*
* <p>Changes in the underlying multimap are reflected in this view.
* Conversely, this view supports removal operations, and these are reflected
* in the underlying multimap.
*
* <p>It's acceptable for the underlying multimap to contain null keys and
* null values provided that the transformer is capable of accepting null
* inputs. The transformed multimap might contain null values if the
* transformer sometimes gives a null result.
*
* <p>The returned multimap is not thread-safe or serializable, even if the
* underlying multimap is.
*
* <p>The transformer is applied lazily, invoked when needed. This is
* necessary for the returned multimap to be a view, but it means that the
* transformer will be applied many times for bulk operations like {@link
* Multimap#containsValue} and {@link Object#toString}. For this to perform
* well, {@code transformer} should be fast. To avoid lazy evaluation when the
* returned multimap doesn't need to be a view, copy the returned multimap
* into a new multimap of your choosing.
*
* <p><b>Warning:</b> This method assumes that for any instance {@code k} of
* {@code EntryTransformer} key type {@code K}, {@code k.equals(k2)} implies
* that {@code k2} is also of type {@code K}. Using an {@code
* EntryTransformer} key type for which this may not hold, such as {@code
* ArrayList}, may risk a {@code ClassCastException} when calling methods on
* the transformed multimap.
*
* @since 7.0
*/
@Beta
public static <K, V1, V2> ListMultimap<K, V2> transformEntries(
ListMultimap<K, V1> fromMap,
EntryTransformer<? super K, ? super V1, V2> transformer) {
return new TransformedEntriesListMultimap<K, V1, V2>(fromMap, transformer);
}
private static final class TransformedEntriesListMultimap<K, V1, V2>
extends TransformedEntriesMultimap<K, V1, V2>
implements ListMultimap<K, V2> {
TransformedEntriesListMultimap(ListMultimap<K, V1> fromMultimap,
EntryTransformer<? super K, ? super V1, V2> transformer) {
super(fromMultimap, transformer);
}
@Override List<V2> transform(final K key, Collection<V1> values) {
return Lists.transform((List<V1>) values, new Function<V1, V2>() {
@Override public V2 apply(V1 value) {
return transformer.transformEntry(key, value);
}
});
}
@Override public List<V2> get(K key) {
return transform(key, fromMultimap.get(key));
}
@SuppressWarnings("unchecked")
@Override public List<V2> removeAll(Object key) {
return transform((K) key, fromMultimap.removeAll(key));
}
@Override public List<V2> replaceValues(
K key, Iterable<? extends V2> values) {
throw new UnsupportedOperationException();
}
}
/**
* Creates an index {@code ImmutableListMultimap} that contains the results of
* applying a specified function to each item in an {@code Iterable} of
* values. Each value will be stored as a value in the resulting multimap,
* yielding a multimap with the same size as the input iterable. The key used
* to store that value in the multimap will be the result of calling the
* function on that value. The resulting multimap is created as an immutable
* snapshot. In the returned multimap, keys appear in the order they are first
* encountered, and the values corresponding to each key appear in the same
* order as they are encountered.
*
* <p>For example, <pre> {@code
*
* List<String> badGuys =
* Arrays.asList("Inky", "Blinky", "Pinky", "Pinky", "Clyde");
* Function<String, Integer> stringLengthFunction = ...;
* Multimap<Integer, String> index =
* Multimaps.index(badGuys, stringLengthFunction);
* System.out.println(index);}</pre>
*
* prints <pre> {@code
*
* {4=[Inky], 6=[Blinky], 5=[Pinky, Pinky, Clyde]}}</pre>
*
* The returned multimap is serializable if its keys and values are all
* serializable.
*
* @param values the values to use when constructing the {@code
* ImmutableListMultimap}
* @param keyFunction the function used to produce the key for each value
* @return {@code ImmutableListMultimap} mapping the result of evaluating the
* function {@code keyFunction} on each value in the input collection to
* that value
* @throws NullPointerException if any of the following cases is true:
* <ul>
* <li>{@code values} is null
* <li>{@code keyFunction} is null
* <li>An element in {@code values} is null
* <li>{@code keyFunction} returns {@code null} for any element of {@code
* values}
* </ul>
*/
public static <K, V> ImmutableListMultimap<K, V> index(
Iterable<V> values, Function<? super V, K> keyFunction) {
return index(values.iterator(), keyFunction);
}
/**
* <b>Deprecated.</b>
*
* @since 10.0
* @deprecated use {@link #index(Iterator, Function)} by casting {@code
* values} to {@code Iterator<V>}, or better yet, by implementing only
* {@code Iterator} and not {@code Iterable}. <b>This method is scheduled
* for deletion in March 2012.</b>
*/
@Beta
@Deprecated
public static <K, V, I extends Object & Iterable<V> & Iterator<V>>
ImmutableListMultimap<K, V> index(
I values, Function<? super V, K> keyFunction) {
Iterable<V> valuesIterable = checkNotNull(values);
return index(valuesIterable, keyFunction);
}
/**
* Creates an index {@code ImmutableListMultimap} that contains the results of
* applying a specified function to each item in an {@code Iterator} of
* values. Each value will be stored as a value in the resulting multimap,
* yielding a multimap with the same size as the input iterator. The key used
* to store that value in the multimap will be the result of calling the
* function on that value. The resulting multimap is created as an immutable
* snapshot. In the returned multimap, keys appear in the order they are first
* encountered, and the values corresponding to each key appear in the same
* order as they are encountered.
*
* <p>For example, <pre> {@code
*
* List<String> badGuys =
* Arrays.asList("Inky", "Blinky", "Pinky", "Pinky", "Clyde");
* Function<String, Integer> stringLengthFunction = ...;
* Multimap<Integer, String> index =
* Multimaps.index(badGuys.iterator(), stringLengthFunction);
* System.out.println(index);}</pre>
*
* prints <pre> {@code
*
* {4=[Inky], 6=[Blinky], 5=[Pinky, Pinky, Clyde]}}</pre>
*
* The returned multimap is serializable if its keys and values are all
* serializable.
*
* @param values the values to use when constructing the {@code
* ImmutableListMultimap}
* @param keyFunction the function used to produce the key for each value
* @return {@code ImmutableListMultimap} mapping the result of evaluating the
* function {@code keyFunction} on each value in the input collection to
* that value
* @throws NullPointerException if any of the following cases is true:
* <ul>
* <li>{@code values} is null
* <li>{@code keyFunction} is null
* <li>An element in {@code values} is null
* <li>{@code keyFunction} returns {@code null} for any element of {@code
* values}
* </ul>
* @since 10.0
*/
public static <K, V> ImmutableListMultimap<K, V> index(
Iterator<V> values, Function<? super V, K> keyFunction) {
checkNotNull(keyFunction);
ImmutableListMultimap.Builder<K, V> builder
= ImmutableListMultimap.builder();
while (values.hasNext()) {
V value = values.next();
checkNotNull(value, values);
builder.put(keyFunction.apply(value), value);
}
return builder.build();
}
static abstract class Keys<K, V> extends AbstractMultiset<K> {
abstract Multimap<K, V> multimap();
@Override Iterator<Multiset.Entry<K>> entryIterator() {
final Iterator<Map.Entry<K, Collection<V>>> backingIterator =
multimap().asMap().entrySet().iterator();
return new Iterator<Multiset.Entry<K>>() {
@Override public boolean hasNext() {
return backingIterator.hasNext();
}
@Override public Multiset.Entry<K> next() {
final Map.Entry<K, Collection<V>> backingEntry =
backingIterator.next();
return new Multisets.AbstractEntry<K>() {
@Override public K getElement() {
return backingEntry.getKey();
}
@Override public int getCount() {
return backingEntry.getValue().size();
}
};
}
@Override public void remove() {
backingIterator.remove();
}
};
}
@Override int distinctElements() {
return multimap().asMap().size();
}
@Override Set<Multiset.Entry<K>> createEntrySet() {
return new KeysEntrySet();
}
class KeysEntrySet extends Multisets.EntrySet<K> {
@Override Multiset<K> multiset() {
return Keys.this;
}
@Override public Iterator<Multiset.Entry<K>> iterator() {
return entryIterator();
}
@Override public int size() {
return distinctElements();
}
@Override public boolean isEmpty() {
return multimap().isEmpty();
}
@Override public boolean contains(@Nullable Object o) {
if (o instanceof Multiset.Entry<?>) {
Multiset.Entry<?> entry = (Multiset.Entry<?>) o;
Collection<V> collection = multimap().asMap().get(entry.getElement());
return collection != null && collection.size() == entry.getCount();
}
return false;
}
@Override public boolean remove(@Nullable Object o) {
if (o instanceof Multiset.Entry<?>) {
Multiset.Entry<?> entry = (Multiset.Entry<?>) o;
Collection<V> collection = multimap().asMap().get(entry.getElement());
if (collection != null && collection.size() == entry.getCount()) {
collection.clear();
return true;
}
}
return false;
}
}
@Override public boolean contains(@Nullable Object element) {
return multimap().containsKey(element);
}
@Override public Iterator<K> iterator() {
return Iterators.transform(multimap().entries().iterator(),
new Function<Map.Entry<K, V>, K>() {
@Override public K apply(Map.Entry<K, V> entry) {
return entry.getKey();
}
});
}
@Override public int count(@Nullable Object element) {
try {
if (multimap().containsKey(element)) {
Collection<V> values = multimap().asMap().get(element);
return (values == null) ? 0 : values.size();
}
return 0;
} catch (ClassCastException e) {
return 0;
} catch (NullPointerException e) {
return 0;
}
}
@Override public int remove(@Nullable Object element, int occurrences) {
checkArgument(occurrences >= 0);
if (occurrences == 0) {
return count(element);
}
Collection<V> values;
try {
values = multimap().asMap().get(element);
} catch (ClassCastException e) {
return 0;
} catch (NullPointerException e) {
return 0;
}
if (values == null) {
return 0;
}
int oldCount = values.size();
if (occurrences >= oldCount) {
values.clear();
} else {
Iterator<V> iterator = values.iterator();
for (int i = 0; i < occurrences; i++) {
iterator.next();
iterator.remove();
}
}
return oldCount;
}
@Override public void clear() {
multimap().clear();
}
@Override public Set<K> elementSet() {
return multimap().keySet();
}
}
static abstract class Values<K, V> extends AbstractCollection<V> {
abstract Multimap<K, V> multimap();
@Override public Iterator<V> iterator() {
final Iterator<Map.Entry<K, V>> backingIterator =
multimap().entries().iterator();
return new Iterator<V>() {
@Override public boolean hasNext() {
return backingIterator.hasNext();
}
@Override public V next() {
return backingIterator.next().getValue();
}
@Override public void remove() {
backingIterator.remove();
}
};
}
@Override public int size() {
return multimap().size();
}
@Override public boolean contains(@Nullable Object o) {
return multimap().containsValue(o);
}
@Override public void clear() {
multimap().clear();
}
}
/**
* A skeleton implementation of {@link Multimap#entries()}.
*/
static abstract class Entries<K, V> extends
AbstractCollection<Map.Entry<K, V>> {
abstract Multimap<K, V> multimap();
@Override public int size() {
return multimap().size();
}
@Override public boolean contains(@Nullable Object o) {
if (o instanceof Map.Entry<?, ?>) {
Map.Entry<?, ?> entry = (Map.Entry<?, ?>) o;
return multimap().containsEntry(entry.getKey(), entry.getValue());
}
return false;
}
@Override public boolean remove(@Nullable Object o) {
if (o instanceof Map.Entry<?, ?>) {
Map.Entry<?, ?> entry = (Map.Entry<?, ?>) o;
return multimap().remove(entry.getKey(), entry.getValue());
}
return false;
}
@Override public void clear() {
multimap().clear();
}
}
/**
* A skeleton implementation of {@link SetMultimap#entries()}.
*/
static abstract class EntrySet<K, V> extends Entries<K, V> implements
Set<Map.Entry<K, V>> {
@Override public int hashCode() {
return Sets.hashCodeImpl(this);
}
@Override public boolean equals(@Nullable Object obj) {
return Sets.equalsImpl(this, obj);
}
}
/**
* A skeleton implementation of {@link Multimap#asMap()}.
*/
static abstract class AsMap<K, V> extends
Maps.ImprovedAbstractMap<K, Collection<V>> {
abstract Multimap<K, V> multimap();
@Override public abstract int size();
abstract Iterator<Entry<K, Collection<V>>> entryIterator();
@Override protected Set<Entry<K, Collection<V>>> createEntrySet() {
return new EntrySet();
}
void removeValuesForKey(Object key){
multimap().removeAll(key);
}
class EntrySet extends Maps.EntrySet<K, Collection<V>> {
@Override Map<K, Collection<V>> map() {
return AsMap.this;
}
@Override public Iterator<Entry<K, Collection<V>>> iterator() {
return entryIterator();
}
@Override public boolean remove(Object o) {
if (!contains(o)) {
return false;
}
Map.Entry<?, ?> entry = (Map.Entry<?, ?>) o;
removeValuesForKey(entry.getKey());
return true;
}
}
@SuppressWarnings("unchecked")
@Override public Collection<V> get(Object key) {
return containsKey(key) ? multimap().get((K) key) : null;
}
@Override public Collection<V> remove(Object key) {
return containsKey(key) ? multimap().removeAll(key) : null;
}
@Override public Set<K> keySet() {
return multimap().keySet();
}
@Override public boolean isEmpty() {
return multimap().isEmpty();
}
@Override public boolean containsKey(Object key) {
return multimap().containsKey(key);
}
@Override public void clear() {
multimap().clear();
}
}
/**
* Support removal operations when filtering a filtered multimap. Since a
* filtered multimap has iterators that don't support remove, passing one to
* the FilteredMultimap constructor would lead to a multimap whose removal
* operations would fail. This method combines the predicates to avoid that
* problem.
*/
private static <K, V> Multimap<K, V> filterFiltered(FilteredMultimap<K, V> map,
Predicate<? super Entry<K, V>> entryPredicate) {
Predicate<Entry<K, V>> predicate
= Predicates.and(map.predicate, entryPredicate);
return new FilteredMultimap<K, V>(map.unfiltered, predicate);
}
private static class FilteredMultimap<K, V> implements Multimap<K, V> {
final Multimap<K, V> unfiltered;
final Predicate<? super Entry<K, V>> predicate;
FilteredMultimap(Multimap<K, V> unfiltered, Predicate<? super Entry<K, V>> predicate) {
this.unfiltered = unfiltered;
this.predicate = predicate;
}
@Override public int size() {
return entries().size();
}
@Override public boolean isEmpty() {
return entries().isEmpty();
}
@Override public boolean containsKey(Object key) {
return asMap().containsKey(key);
}
@Override public boolean containsValue(Object value) {
return values().contains(value);
}
// This method should be called only when key is a K and value is a V.
@SuppressWarnings("unchecked")
boolean satisfiesPredicate(Object key, Object value) {
return predicate.apply(Maps.immutableEntry((K) key, (V) value));
}
@Override public boolean containsEntry(Object key, Object value) {
return unfiltered.containsEntry(key, value) && satisfiesPredicate(key, value);
}
@Override public boolean put(K key, V value) {
checkArgument(satisfiesPredicate(key, value));
return unfiltered.put(key, value);
}
@Override public boolean remove(Object key, Object value) {
return containsEntry(key, value) ? unfiltered.remove(key, value) : false;
}
@Override public boolean putAll(K key, Iterable<? extends V> values) {
for (V value : values) {
checkArgument(satisfiesPredicate(key, value));
}
return unfiltered.putAll(key, values);
}
@Override public boolean putAll(Multimap<? extends K, ? extends V> multimap) {
for (Entry<? extends K, ? extends V> entry : multimap.entries()) {
checkArgument(satisfiesPredicate(entry.getKey(), entry.getValue()));
}
return unfiltered.putAll(multimap);
}
@Override public Collection<V> replaceValues(K key, Iterable<? extends V> values) {
for (V value : values) {
checkArgument(satisfiesPredicate(key, value));
}
// Not calling unfiltered.replaceValues() since values that don't satisify
// the filter should remain in the multimap.
Collection<V> oldValues = removeAll(key);
unfiltered.putAll(key, values);
return oldValues;
}
@Override public Collection<V> removeAll(Object key) {
List<V> removed = Lists.newArrayList();
Collection<V> values = unfiltered.asMap().get(key);
if (values != null) {
Iterator<V> iterator = values.iterator();
while (iterator.hasNext()) {
V value = iterator.next();
if (satisfiesPredicate(key, value)) {
removed.add(value);
iterator.remove();
}
}
}
if (unfiltered instanceof SetMultimap) {
return Collections.unmodifiableSet(Sets.newLinkedHashSet(removed));
} else {
return Collections.unmodifiableList(removed);
}
}
@Override public void clear() {
entries().clear();
}
@Override public boolean equals(@Nullable Object object) {
if (object == this) {
return true;
}
if (object instanceof Multimap) {
Multimap<?, ?> that = (Multimap<?, ?>) object;
return asMap().equals(that.asMap());
}
return false;
}
@Override public int hashCode() {
return asMap().hashCode();
}
@Override public String toString() {
return asMap().toString();
}
class ValuePredicate implements Predicate<V> {
final K key;
ValuePredicate(K key) {
this.key = key;
}
@Override public boolean apply(V value) {
return satisfiesPredicate(key, value);
}
}
Collection<V> filterCollection(Collection<V> collection, Predicate<V> predicate) {
if (collection instanceof Set) {
return Sets.filter((Set<V>) collection, predicate);
} else {
return Collections2.filter(collection, predicate);
}
}
@Override public Collection<V> get(K key) {
return filterCollection(unfiltered.get(key), new ValuePredicate(key));
}
@Override public Set<K> keySet() {
return asMap().keySet();
}
Collection<V> values;
@Override public Collection<V> values() {
return (values == null) ? values = new Values() : values;
}
class Values extends Multimaps.Values<K, V> {
@Override Multimap<K, V> multimap() {
return FilteredMultimap.this;
}
@Override public boolean contains(@Nullable Object o) {
return Iterators.contains(iterator(), o);
}
// Override remove methods since iterator doesn't support remove.
@Override public boolean remove(Object o) {
Iterator<Entry<K, V>> iterator = unfiltered.entries().iterator();
while (iterator.hasNext()) {
Entry<K, V> entry = iterator.next();
if (Objects.equal(o, entry.getValue()) && predicate.apply(entry)) {
iterator.remove();
return true;
}
}
return false;
}
@Override public boolean removeAll(Collection<?> c) {
boolean changed = false;
Iterator<Entry<K, V>> iterator = unfiltered.entries().iterator();
while (iterator.hasNext()) {
Entry<K, V> entry = iterator.next();
if (c.contains(entry.getValue()) && predicate.apply(entry)) {
iterator.remove();
changed = true;
}
}
return changed;
}
@Override public boolean retainAll(Collection<?> c) {
boolean changed = false;
Iterator<Entry<K, V>> iterator = unfiltered.entries().iterator();
while (iterator.hasNext()) {
Entry<K, V> entry = iterator.next();
if (!c.contains(entry.getValue()) && predicate.apply(entry)) {
iterator.remove();
changed = true;
}
}
return changed;
}
}
Collection<Entry<K, V>> entries;
@Override public Collection<Entry<K, V>> entries() {
return (entries == null)
? entries = Collections2.filter(unfiltered.entries(), predicate)
: entries;
}
/**
* Remove all filtered asMap() entries that satisfy the predicate.
*/
boolean removeEntriesIf(Predicate<Map.Entry<K, Collection<V>>> removalPredicate) {
Iterator<Map.Entry<K, Collection<V>>> iterator = unfiltered.asMap().entrySet().iterator();
boolean changed = false;
while (iterator.hasNext()) {
// Determine whether to remove the filtered values with this key.
Map.Entry<K, Collection<V>> entry = iterator.next();
K key = entry.getKey();
Collection<V> collection = entry.getValue();
Predicate<V> valuePredicate = new ValuePredicate(key);
Collection<V> filteredCollection = filterCollection(collection, valuePredicate);
Map.Entry<K, Collection<V>> filteredEntry = Maps.immutableEntry(key, filteredCollection);
if (removalPredicate.apply(filteredEntry) && !filteredCollection.isEmpty()) {
changed = true;
if (Iterables.all(collection, valuePredicate)) {
iterator.remove(); // Remove all values for the key.
} else {
filteredCollection.clear(); // Remove the filtered values only.
}
}
}
return changed;
}
Map<K, Collection<V>> asMap;
@Override public Map<K, Collection<V>> asMap() {
return (asMap == null) ? asMap = createAsMap() : asMap;
}
static final Predicate<Collection<?>> NOT_EMPTY = new Predicate<Collection<?>>() {
@Override public boolean apply(Collection<?> input) {
return !input.isEmpty();
}
};
Map<K, Collection<V>> createAsMap() {
// Select the values that satisify the predicate.
EntryTransformer<K, Collection<V>, Collection<V>> transformer
= new EntryTransformer<K, Collection<V>, Collection<V>>() {
@Override public Collection<V> transformEntry(K key, Collection<V> collection) {
return filterCollection(collection, new ValuePredicate(key));
}
};
Map<K, Collection<V>> transformed
= Maps.transformEntries(unfiltered.asMap(), transformer);
// Select the keys that have at least one value remaining.
Map<K, Collection<V>> filtered = Maps.filterValues(transformed, NOT_EMPTY);
// Override the removal methods, since removing a map entry should not
// affect values that don't satisfy the filter.
return new AsMap(filtered);
}
class AsMap extends ForwardingMap<K, Collection<V>> {
final Map<K, Collection<V>> delegate;
AsMap(Map<K, Collection<V>> delegate) {
this.delegate = delegate;
}
@Override protected Map<K, Collection<V>> delegate() {
return delegate;
}
@Override public Collection<V> remove(Object o) {
Collection<V> output = FilteredMultimap.this.removeAll(o);
return output.isEmpty() ? null : output;
}
@Override public void clear() {
FilteredMultimap.this.clear();
}
Set<K> keySet;
@Override public Set<K> keySet() {
return (keySet == null) ? keySet = new KeySet() : keySet;
}
class KeySet extends Maps.KeySet<K, Collection<V>> {
@Override Map<K, Collection<V>> map() {
return AsMap.this;
}
@Override public boolean remove(Object o) {
Collection<V> collection = delegate.get(o);
if (collection == null) {
return false;
}
collection.clear();
return true;
}
@Override public boolean removeAll(Collection<?> c) {
return Sets.removeAllImpl(this, c);
}
@Override public boolean retainAll(final Collection<?> c) {
Predicate<Map.Entry<K, Collection<V>>> removalPredicate
= new Predicate<Map.Entry<K, Collection<V>>>() {
@Override public boolean apply(Map.Entry<K, Collection<V>> entry) {
return !c.contains(entry.getKey());
}
};
return removeEntriesIf(removalPredicate);
}
}
Values asMapValues;
@Override public Collection<Collection<V>> values() {
return (asMapValues == null) ? asMapValues = new Values() : asMapValues;
}
class Values extends Maps.Values<K, Collection<V>> {
@Override Map<K, Collection<V>> map() {
return AsMap.this;
}
@Override public boolean remove(Object o) {
for (Collection<V> collection : this) {
if (collection.equals(o)) {
collection.clear();
return true;
}
}
return false;
}
@Override public boolean removeAll(final Collection<?> c) {
Predicate<Map.Entry<K, Collection<V>>> removalPredicate
= new Predicate<Map.Entry<K, Collection<V>>>() {
@Override public boolean apply(Map.Entry<K, Collection<V>> entry) {
return c.contains(entry.getValue());
}
};
return removeEntriesIf(removalPredicate);
}
@Override public boolean retainAll(final Collection<?> c) {
Predicate<Map.Entry<K, Collection<V>>> removalPredicate
= new Predicate<Map.Entry<K, Collection<V>>>() {
@Override public boolean apply(Map.Entry<K, Collection<V>> entry) {
return !c.contains(entry.getValue());
}
};
return removeEntriesIf(removalPredicate);
}
}
EntrySet entrySet;
@Override public Set<Map.Entry<K, Collection<V>>> entrySet() {
return (entrySet == null) ? entrySet = new EntrySet(super.entrySet()) : entrySet;
}
class EntrySet extends Maps.EntrySet<K, Collection<V>> {
Set<Map.Entry<K, Collection<V>>> delegateEntries;
public EntrySet(Set<Map.Entry<K, Collection<V>>> delegateEntries) {
this.delegateEntries = delegateEntries;
}
@Override Map<K, Collection<V>> map() {
return AsMap.this;
}
@Override public Iterator<Map.Entry<K, Collection<V>>> iterator() {
return delegateEntries.iterator();
}
@Override public boolean remove(Object o) {
if (o instanceof Entry<?, ?>) {
Entry<?, ?> entry = (Entry<?, ?>) o;
Collection<V> collection = delegate.get(entry.getKey());
if (collection != null && collection.equals(entry.getValue())) {
collection.clear();
return true;
}
}
return false;
}
@Override public boolean removeAll(Collection<?> c) {
return Sets.removeAllImpl(this, c);
}
@Override public boolean retainAll(final Collection<?> c) {
Predicate<Map.Entry<K, Collection<V>>> removalPredicate
= new Predicate<Map.Entry<K, Collection<V>>>() {
@Override public boolean apply(Map.Entry<K, Collection<V>> entry) {
return !c.contains(entry);
}
};
return removeEntriesIf(removalPredicate);
}
}
}
AbstractMultiset<K> keys;
@Override public Multiset<K> keys() {
return (keys == null) ? keys = new Keys() : keys;
}
class Keys extends Multimaps.Keys<K, V> {
@Override Multimap<K, V> multimap() {
return FilteredMultimap.this;
}
@Override public int remove(Object o, int occurrences) {
checkArgument(occurrences >= 0);
Collection<V> values = unfiltered.asMap().get(o);
if (values == null) {
return 0;
}
int priorCount = 0;
int removed = 0;
Iterator<V> iterator = values.iterator();
while (iterator.hasNext()) {
if (satisfiesPredicate(o, iterator.next())) {
priorCount++;
if (removed < occurrences) {
iterator.remove();
removed++;
}
}
}
return priorCount;
}
@Override Set<Multiset.Entry<K>> createEntrySet() {
return new EntrySet();
}
class EntrySet extends Multimaps.Keys<K, V>.KeysEntrySet {
@Override public boolean removeAll(Collection<?> c) {
return Sets.removeAllImpl(this, c);
}
@Override public boolean retainAll(final Collection<?> c) {
Predicate<Map.Entry<K, Collection<V>>> removalPredicate
= new Predicate<Map.Entry<K, Collection<V>>>() {
@Override public boolean apply(Map.Entry<K, Collection<V>> entry) {
Multiset.Entry<K> multisetEntry
= Multisets.immutableEntry(entry.getKey(), entry.getValue().size());
return !c.contains(multisetEntry);
}
};
return removeEntriesIf(removalPredicate);
}
}
}
}
// TODO(jlevy): Create methods that filter a SetMultimap or SortedSetMultimap.
}
| Java |
/*
* Copyright (C) 2007 The Guava Authors
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package com.google.common.collect;
import com.google.common.annotations.GwtCompatible;
import com.google.common.annotations.VisibleForTesting;
import com.google.common.base.Preconditions;
import com.google.common.primitives.Ints;
import java.util.Collection;
import java.util.Iterator;
import java.util.LinkedHashMap;
import java.util.LinkedHashSet;
import java.util.Map;
import java.util.Set;
import javax.annotation.Nullable;
/**
* Implementation of {@code Multimap} that does not allow duplicate key-value
* entries and that returns collections whose iterators follow the ordering in
* which the data was added to the multimap.
*
* <p>The collections returned by {@code keySet}, {@code keys}, and {@code
* asMap} iterate through the keys in the order they were first added to the
* multimap. Similarly, {@code get}, {@code removeAll}, and {@code
* replaceValues} return collections that iterate through the values in the
* order they were added. The collections generated by {@code entries} and
* {@code values} iterate across the key-value mappings in the order they were
* added to the multimap.
*
* <p>The iteration ordering of the collections generated by {@code keySet},
* {@code keys}, and {@code asMap} has a few subtleties. As long as the set of
* keys remains unchanged, adding or removing mappings does not affect the key
* iteration order. However, if you remove all values associated with a key and
* then add the key back to the multimap, that key will come last in the key
* iteration order.
*
* <p>The multimap does not store duplicate key-value pairs. Adding a new
* key-value pair equal to an existing key-value pair has no effect.
*
* <p>Keys and values may be null. All optional multimap methods are supported,
* and all returned views are modifiable.
*
* <p>This class is not threadsafe when any concurrent operations update the
* multimap. Concurrent read operations will work correctly. To allow concurrent
* update operations, wrap your multimap with a call to {@link
* Multimaps#synchronizedSetMultimap}.
*
* <p>See the Guava User Guide article on <a href=
* "http://code.google.com/p/guava-libraries/wiki/NewCollectionTypesExplained#Multimap">
* {@code Multimap}</a>.
*
* @author Jared Levy
* @since 2.0 (imported from Google Collections Library)
*/
@GwtCompatible(serializable = true, emulated = true)
public final class LinkedHashMultimap<K, V> extends AbstractSetMultimap<K, V> {
private static final int DEFAULT_VALUES_PER_KEY = 8;
@VisibleForTesting
transient int expectedValuesPerKey = DEFAULT_VALUES_PER_KEY;
/**
* Map entries with an iteration order corresponding to the order in which the
* key-value pairs were added to the multimap.
*/
// package-private for GWT deserialization
transient Collection<Map.Entry<K, V>> linkedEntries;
/**
* Creates a new, empty {@code LinkedHashMultimap} with the default initial
* capacities.
*/
public static <K, V> LinkedHashMultimap<K, V> create() {
return new LinkedHashMultimap<K, V>();
}
/**
* Constructs an empty {@code LinkedHashMultimap} with enough capacity to hold
* the specified numbers of keys and values without rehashing.
*
* @param expectedKeys the expected number of distinct keys
* @param expectedValuesPerKey the expected average number of values per key
* @throws IllegalArgumentException if {@code expectedKeys} or {@code
* expectedValuesPerKey} is negative
*/
public static <K, V> LinkedHashMultimap<K, V> create(
int expectedKeys, int expectedValuesPerKey) {
return new LinkedHashMultimap<K, V>(expectedKeys, expectedValuesPerKey);
}
/**
* Constructs a {@code LinkedHashMultimap} with the same mappings as the
* specified multimap. If a key-value mapping appears multiple times in the
* input multimap, it only appears once in the constructed multimap. The new
* multimap has the same {@link Multimap#entries()} iteration order as the
* input multimap, except for excluding duplicate mappings.
*
* @param multimap the multimap whose contents are copied to this multimap
*/
public static <K, V> LinkedHashMultimap<K, V> create(
Multimap<? extends K, ? extends V> multimap) {
return new LinkedHashMultimap<K, V>(multimap);
}
private LinkedHashMultimap() {
super(new LinkedHashMap<K, Collection<V>>());
linkedEntries = Sets.newLinkedHashSet();
}
private LinkedHashMultimap(int expectedKeys, int expectedValuesPerKey) {
super(new LinkedHashMap<K, Collection<V>>(expectedKeys));
Preconditions.checkArgument(expectedValuesPerKey >= 0);
this.expectedValuesPerKey = expectedValuesPerKey;
linkedEntries = new LinkedHashSet<Map.Entry<K, V>>(
(int) Math.min(Ints.MAX_POWER_OF_TWO,
((long) expectedKeys) * expectedValuesPerKey));
}
private LinkedHashMultimap(Multimap<? extends K, ? extends V> multimap) {
super(new LinkedHashMap<K, Collection<V>>(
Maps.capacity(multimap.keySet().size())));
linkedEntries
= new LinkedHashSet<Map.Entry<K, V>>(Maps.capacity(multimap.size()));
putAll(multimap);
}
/**
* {@inheritDoc}
*
* <p>Creates an empty {@code LinkedHashSet} for a collection of values for
* one key.
*
* @return a new {@code LinkedHashSet} containing a collection of values for
* one key
*/
@Override Set<V> createCollection() {
return new LinkedHashSet<V>(Maps.capacity(expectedValuesPerKey));
}
/**
* {@inheritDoc}
*
* <p>Creates a decorated {@code LinkedHashSet} that also keeps track of the
* order in which key-value pairs are added to the multimap.
*
* @param key key to associate with values in the collection
* @return a new decorated {@code LinkedHashSet} containing a collection of
* values for one key
*/
@Override Collection<V> createCollection(@Nullable K key) {
return new SetDecorator(key, createCollection());
}
private class SetDecorator extends ForwardingSet<V> {
final Set<V> delegate;
final K key;
SetDecorator(@Nullable K key, Set<V> delegate) {
this.delegate = delegate;
this.key = key;
}
@Override protected Set<V> delegate() {
return delegate;
}
<E> Map.Entry<K, E> createEntry(@Nullable E value) {
return Maps.immutableEntry(key, value);
}
<E> Collection<Map.Entry<K, E>> createEntries(Collection<E> values) {
// converts a collection of values into a list of key/value map entries
Collection<Map.Entry<K, E>> entries
= Lists.newArrayListWithExpectedSize(values.size());
for (E value : values) {
entries.add(createEntry(value));
}
return entries;
}
@Override public boolean add(@Nullable V value) {
boolean changed = delegate.add(value);
if (changed) {
linkedEntries.add(createEntry(value));
}
return changed;
}
@Override public boolean addAll(Collection<? extends V> values) {
boolean changed = delegate.addAll(values);
if (changed) {
linkedEntries.addAll(createEntries(delegate()));
}
return changed;
}
@Override public void clear() {
for (V value : delegate) {
linkedEntries.remove(createEntry(value));
}
delegate.clear();
}
@Override public Iterator<V> iterator() {
final Iterator<V> delegateIterator = delegate.iterator();
return new Iterator<V>() {
V value;
@Override
public boolean hasNext() {
return delegateIterator.hasNext();
}
@Override
public V next() {
value = delegateIterator.next();
return value;
}
@Override
public void remove() {
delegateIterator.remove();
linkedEntries.remove(createEntry(value));
}
};
}
@Override public boolean remove(@Nullable Object value) {
boolean changed = delegate.remove(value);
if (changed) {
/*
* linkedEntries.remove() will return false when this method is called
* by entries().iterator().remove()
*/
linkedEntries.remove(createEntry(value));
}
return changed;
}
@Override public boolean removeAll(Collection<?> values) {
boolean changed = delegate.removeAll(values);
if (changed) {
linkedEntries.removeAll(createEntries(values));
}
return changed;
}
@Override public boolean retainAll(Collection<?> values) {
/*
* Calling linkedEntries.retainAll() would incorrectly remove values
* with other keys.
*/
boolean changed = false;
Iterator<V> iterator = delegate.iterator();
while (iterator.hasNext()) {
V value = iterator.next();
if (!values.contains(value)) {
iterator.remove();
linkedEntries.remove(Maps.immutableEntry(key, value));
changed = true;
}
}
return changed;
}
}
/**
* {@inheritDoc}
*
* <p>Generates an iterator across map entries that follows the ordering in
* which the key-value pairs were added to the multimap.
*
* @return a key-value iterator with the correct ordering
*/
@Override Iterator<Map.Entry<K, V>> createEntryIterator() {
final Iterator<Map.Entry<K, V>> delegateIterator = linkedEntries.iterator();
return new Iterator<Map.Entry<K, V>>() {
Map.Entry<K, V> entry;
@Override
public boolean hasNext() {
return delegateIterator.hasNext();
}
@Override
public Map.Entry<K, V> next() {
entry = delegateIterator.next();
return entry;
}
@Override
public void remove() {
// Remove from iterator first to keep iterator valid.
delegateIterator.remove();
LinkedHashMultimap.this.remove(entry.getKey(), entry.getValue());
}
};
}
/**
* {@inheritDoc}
*
* <p>If {@code values} is not empty and the multimap already contains a
* mapping for {@code key}, the {@code keySet()} ordering is unchanged.
* However, the provided values always come last in the {@link #entries()} and
* {@link #values()} iteration orderings.
*/
@Override public Set<V> replaceValues(
@Nullable K key, Iterable<? extends V> values) {
return super.replaceValues(key, values);
}
/**
* Returns a set of all key-value pairs. Changes to the returned set will
* update the underlying multimap, and vice versa. The entries set does not
* support the {@code add} or {@code addAll} operations.
*
* <p>The iterator generated by the returned set traverses the entries in the
* order they were added to the multimap.
*
* <p>Each entry is an immutable snapshot of a key-value mapping in the
* multimap, taken at the time the entry is returned by a method call to the
* collection or its iterator.
*/
@Override public Set<Map.Entry<K, V>> entries() {
return super.entries();
}
/**
* Returns a collection of all values in the multimap. Changes to the returned
* collection will update the underlying multimap, and vice versa.
*
* <p>The iterator generated by the returned collection traverses the values
* in the order they were added to the multimap.
*/
@Override public Collection<V> values() {
return super.values();
}
// Unfortunately, the entries() ordering does not determine the key ordering;
// see the example in the LinkedListMultimap class Javadoc.
}
| Java |
/*
* Copyright (C) 2009 The Guava Authors
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package com.google.common.collect;
import java.util.SortedSet;
/**
* GWT emulation of {@link RegularImmutableSortedSet}.
*
* @author Hayward Chan
*/
final class RegularImmutableSortedSet<E> extends ImmutableSortedSet<E> {
/** true if this set is a subset of another immutable sorted set. */
final boolean isSubset;
RegularImmutableSortedSet(SortedSet<E> delegate, boolean isSubset) {
super(delegate);
this.isSubset = isSubset;
}
}
| Java |
/*
* Copyright (C) 2007 The Guava Authors
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package com.google.common.collect;
import static com.google.common.base.Preconditions.checkArgument;
import static com.google.common.base.Preconditions.checkNotNull;
import static com.google.common.base.Preconditions.checkState;
import static com.google.common.collect.Multisets.checkNonnegative;
import com.google.common.annotations.GwtCompatible;
import com.google.common.primitives.Ints;
import java.io.Serializable;
import java.util.Collection;
import java.util.ConcurrentModificationException;
import java.util.Iterator;
import java.util.Map;
import java.util.Set;
import javax.annotation.Nullable;
/**
* Basic implementation of {@code Multiset<E>} backed by an instance of {@code
* Map<E, AtomicInteger>}.
*
* <p>For serialization to work, the subclass must specify explicit {@code
* readObject} and {@code writeObject} methods.
*
* @author Kevin Bourrillion
*/
@GwtCompatible(emulated = true)
abstract class AbstractMapBasedMultiset<E> extends AbstractMultiset<E>
implements Serializable {
private transient Map<E, Count> backingMap;
/*
* Cache the size for efficiency. Using a long lets us avoid the need for
* overflow checking and ensures that size() will function correctly even if
* the multiset had once been larger than Integer.MAX_VALUE.
*/
private transient long size;
/** Standard constructor. */
protected AbstractMapBasedMultiset(Map<E, Count> backingMap) {
this.backingMap = checkNotNull(backingMap);
this.size = super.size();
}
Map<E, Count> backingMap() {
return backingMap;
}
/** Used during deserialization only. The backing map must be empty. */
void setBackingMap(Map<E, Count> backingMap) {
this.backingMap = backingMap;
}
// Required Implementations
/**
* {@inheritDoc}
*
* <p>Invoking {@link Multiset.Entry#getCount} on an entry in the returned
* set always returns the current count of that element in the multiset, as
* opposed to the count at the time the entry was retrieved.
*/
@Override
public Set<Multiset.Entry<E>> entrySet() {
return super.entrySet();
}
@Override
Iterator<Entry<E>> entryIterator() {
final Iterator<Map.Entry<E, Count>> backingEntries =
backingMap.entrySet().iterator();
return new Iterator<Multiset.Entry<E>>() {
Map.Entry<E, Count> toRemove;
@Override
public boolean hasNext() {
return backingEntries.hasNext();
}
@Override
public Multiset.Entry<E> next() {
final Map.Entry<E, Count> mapEntry = backingEntries.next();
toRemove = mapEntry;
return new Multisets.AbstractEntry<E>() {
@Override
public E getElement() {
return mapEntry.getKey();
}
@Override
public int getCount() {
int count = mapEntry.getValue().get();
if (count == 0) {
Count frequency = backingMap.get(getElement());
if (frequency != null) {
count = frequency.get();
}
}
return count;
}
};
}
@Override
public void remove() {
checkState(toRemove != null,
"no calls to next() since the last call to remove()");
size -= toRemove.getValue().getAndSet(0);
backingEntries.remove();
toRemove = null;
}
};
}
@Override
public void clear() {
for (Count frequency : backingMap.values()) {
frequency.set(0);
}
backingMap.clear();
size = 0L;
}
@Override
int distinctElements() {
return backingMap.size();
}
// Optimizations - Query Operations
@Override public int size() {
return Ints.saturatedCast(size);
}
@Override public Iterator<E> iterator() {
return new MapBasedMultisetIterator();
}
/*
* Not subclassing AbstractMultiset$MultisetIterator because next() needs to
* retrieve the Map.Entry<E, AtomicInteger> entry, which can then be used for
* a more efficient remove() call.
*/
private class MapBasedMultisetIterator implements Iterator<E> {
final Iterator<Map.Entry<E, Count>> entryIterator;
Map.Entry<E, Count> currentEntry;
int occurrencesLeft;
boolean canRemove;
MapBasedMultisetIterator() {
this.entryIterator = backingMap.entrySet().iterator();
}
@Override
public boolean hasNext() {
return occurrencesLeft > 0 || entryIterator.hasNext();
}
@Override
public E next() {
if (occurrencesLeft == 0) {
currentEntry = entryIterator.next();
occurrencesLeft = currentEntry.getValue().get();
}
occurrencesLeft--;
canRemove = true;
return currentEntry.getKey();
}
@Override
public void remove() {
checkState(canRemove,
"no calls to next() since the last call to remove()");
int frequency = currentEntry.getValue().get();
if (frequency <= 0) {
throw new ConcurrentModificationException();
}
if (currentEntry.getValue().addAndGet(-1) == 0) {
entryIterator.remove();
}
size--;
canRemove = false;
}
}
@Override public int count(@Nullable Object element) {
try {
Count frequency = backingMap.get(element);
return (frequency == null) ? 0 : frequency.get();
} catch (NullPointerException e) {
return 0;
} catch (ClassCastException e) {
return 0;
}
}
// Optional Operations - Modification Operations
/**
* {@inheritDoc}
*
* @throws IllegalArgumentException if the call would result in more than
* {@link Integer#MAX_VALUE} occurrences of {@code element} in this
* multiset.
*/
@Override public int add(@Nullable E element, int occurrences) {
if (occurrences == 0) {
return count(element);
}
checkArgument(
occurrences > 0, "occurrences cannot be negative: %s", occurrences);
Count frequency = backingMap.get(element);
int oldCount;
if (frequency == null) {
oldCount = 0;
backingMap.put(element, new Count(occurrences));
} else {
oldCount = frequency.get();
long newCount = (long) oldCount + (long) occurrences;
checkArgument(newCount <= Integer.MAX_VALUE,
"too many occurrences: %s", newCount);
frequency.getAndAdd(occurrences);
}
size += occurrences;
return oldCount;
}
@Override public int remove(@Nullable Object element, int occurrences) {
if (occurrences == 0) {
return count(element);
}
checkArgument(
occurrences > 0, "occurrences cannot be negative: %s", occurrences);
Count frequency = backingMap.get(element);
if (frequency == null) {
return 0;
}
int oldCount = frequency.get();
int numberRemoved;
if (oldCount > occurrences) {
numberRemoved = occurrences;
} else {
numberRemoved = oldCount;
backingMap.remove(element);
}
frequency.addAndGet(-numberRemoved);
size -= numberRemoved;
return oldCount;
}
// Roughly a 33% performance improvement over AbstractMultiset.setCount().
@Override public int setCount(E element, int count) {
checkNonnegative(count, "count");
Count existingCounter;
int oldCount;
if (count == 0) {
existingCounter = backingMap.remove(element);
oldCount = getAndSet(existingCounter, count);
} else {
existingCounter = backingMap.get(element);
oldCount = getAndSet(existingCounter, count);
if (existingCounter == null) {
backingMap.put(element, new Count(count));
}
}
size += (count - oldCount);
return oldCount;
}
private static int getAndSet(Count i, int count) {
if (i == null) {
return 0;
}
return i.getAndSet(count);
}
private int removeAllOccurrences(@Nullable Object element,
Map<E, Count> map) {
Count frequency = map.remove(element);
if (frequency == null) {
return 0;
}
int numberRemoved = frequency.getAndSet(0);
size -= numberRemoved;
return numberRemoved;
}
// Views
@Override Set<E> createElementSet() {
return new MapBasedElementSet(backingMap);
}
// TODO(user): once TreeMultiset is replaced with a SortedMultiset
// implementation, replace this with a subclass of Multisets.ElementSet.
class MapBasedElementSet extends ForwardingSet<E> {
// This mapping is the usually the same as 'backingMap', but can be a
// submap in some implementations.
private final Map<E, Count> map;
private final Set<E> delegate;
MapBasedElementSet(Map<E, Count> map) {
this.map = map;
delegate = map.keySet();
}
@Override protected Set<E> delegate() {
return delegate;
}
@Override public Iterator<E> iterator() {
final Iterator<Map.Entry<E, Count>> entries
= map.entrySet().iterator();
return new Iterator<E>() {
Map.Entry<E, Count> toRemove;
@Override
public boolean hasNext() {
return entries.hasNext();
}
@Override
public E next() {
toRemove = entries.next();
return toRemove.getKey();
}
@Override
public void remove() {
checkState(toRemove != null,
"no calls to next() since the last call to remove()");
size -= toRemove.getValue().getAndSet(0);
entries.remove();
toRemove = null;
}
};
}
@Override public boolean remove(Object element) {
return removeAllOccurrences(element, map) != 0;
}
@Override public boolean removeAll(Collection<?> elementsToRemove) {
return Iterators.removeAll(iterator(), elementsToRemove);
}
@Override public boolean retainAll(Collection<?> elementsToRetain) {
return Iterators.retainAll(iterator(), elementsToRetain);
}
@Override public void clear() {
if (map == backingMap) {
AbstractMapBasedMultiset.this.clear();
} else {
Iterator<E> i = iterator();
while (i.hasNext()) {
i.next();
i.remove();
}
}
}
public Map<E, Count> getMap() {
return map;
}
}
// Don't allow default serialization.
}
| Java |
/*
* Copyright (C) 2010 The Guava Authors
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS-IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package com.google.common.collect;
import com.google.common.annotations.Beta;
import com.google.common.annotations.GwtCompatible;
import com.google.common.base.Function;
import java.util.concurrent.ConcurrentMap;
import java.util.concurrent.TimeUnit;
/**
* A class exactly like {@link MapMaker}, except restricted in the types of maps it can build.
* For the most part, you should probably just ignore the existence of this class.
*
* @param <K0> the base type for all key types of maps built by this map maker
* @param <V0> the base type for all value types of maps built by this map maker
* @author Kevin Bourrillion
* @since 7.0
*/
@Beta
@GwtCompatible(emulated = true)
public abstract class GenericMapMaker<K0, V0> {
// Set by MapMaker, but sits in this class to preserve the type relationship
// No subclasses but our own
GenericMapMaker() {}
/**
* See {@link MapMaker#initialCapacity}.
*/
public abstract GenericMapMaker<K0, V0> initialCapacity(int initialCapacity);
/**
* See {@link MapMaker#maximumSize}.
*/
abstract GenericMapMaker<K0, V0> maximumSize(int maximumSize);
/**
* See {@link MapMaker#strongKeys}.
*/
abstract GenericMapMaker<K0, V0> strongKeys();
/**
* See {@link MapMaker#concurrencyLevel}.
*/
public abstract GenericMapMaker<K0, V0> concurrencyLevel(int concurrencyLevel);
/**
* See {@link MapMaker#strongValues}.
*/
abstract GenericMapMaker<K0, V0> strongValues();
/**
* See {@link MapMaker#expiration}.
*/
@Deprecated
public
abstract GenericMapMaker<K0, V0> expiration(long duration, TimeUnit unit);
/**
* See {@link MapMaker#expireAfterWrite}.
*/
abstract GenericMapMaker<K0, V0> expireAfterWrite(long duration, TimeUnit unit);
/*
* Note that MapMaker's removalListener() is not here, because once you're interacting with a
* GenericMapMaker you've already called that, and shouldn't be calling it again.
*/
/**
* See {@link MapMaker#makeMap}.
*/
public abstract <K extends K0, V extends V0> ConcurrentMap<K, V> makeMap();
/**
* See {@link MapMaker#makeComputingMap}.
*/
@Deprecated
public abstract <K extends K0, V extends V0> ConcurrentMap<K, V> makeComputingMap(
Function<? super K, ? extends V> computingFunction);
}
| Java |
/*
* Copyright (C) 2007 The Guava Authors
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package com.google.common.collect;
import static com.google.common.base.Preconditions.checkArgument;
import com.google.common.annotations.GwtCompatible;
import com.google.common.annotations.VisibleForTesting;
import java.util.ArrayList;
import java.util.Collection;
import java.util.HashMap;
import java.util.List;
/**
* Implementation of {@code Multimap} that uses an {@code ArrayList} to store
* the values for a given key. A {@link HashMap} associates each key with an
* {@link ArrayList} of values.
*
* <p>When iterating through the collections supplied by this class, the
* ordering of values for a given key agrees with the order in which the values
* were added.
*
* <p>This multimap allows duplicate key-value pairs. After adding a new
* key-value pair equal to an existing key-value pair, the {@code
* ArrayListMultimap} will contain entries for both the new value and the old
* value.
*
* <p>Keys and values may be null. All optional multimap methods are supported,
* and all returned views are modifiable.
*
* <p>The lists returned by {@link #get}, {@link #removeAll}, and {@link
* #replaceValues} all implement {@link java.util.RandomAccess}.
*
* <p>This class is not threadsafe when any concurrent operations update the
* multimap. Concurrent read operations will work correctly. To allow concurrent
* update operations, wrap your multimap with a call to {@link
* Multimaps#synchronizedListMultimap}.
*
* <p>See the Guava User Guide article on <a href=
* "http://code.google.com/p/guava-libraries/wiki/NewCollectionTypesExplained#Multimap">
* {@code Multimap}</a>.
*
* @author Jared Levy
* @since 2.0 (imported from Google Collections Library)
*/
@GwtCompatible(serializable = true, emulated = true)
public final class ArrayListMultimap<K, V> extends AbstractListMultimap<K, V> {
// Default from ArrayList
private static final int DEFAULT_VALUES_PER_KEY = 10;
@VisibleForTesting transient int expectedValuesPerKey;
/**
* Creates a new, empty {@code ArrayListMultimap} with the default initial
* capacities.
*/
public static <K, V> ArrayListMultimap<K, V> create() {
return new ArrayListMultimap<K, V>();
}
/**
* Constructs an empty {@code ArrayListMultimap} with enough capacity to hold
* the specified numbers of keys and values without resizing.
*
* @param expectedKeys the expected number of distinct keys
* @param expectedValuesPerKey the expected average number of values per key
* @throws IllegalArgumentException if {@code expectedKeys} or {@code
* expectedValuesPerKey} is negative
*/
public static <K, V> ArrayListMultimap<K, V> create(
int expectedKeys, int expectedValuesPerKey) {
return new ArrayListMultimap<K, V>(expectedKeys, expectedValuesPerKey);
}
/**
* Constructs an {@code ArrayListMultimap} with the same mappings as the
* specified multimap.
*
* @param multimap the multimap whose contents are copied to this multimap
*/
public static <K, V> ArrayListMultimap<K, V> create(
Multimap<? extends K, ? extends V> multimap) {
return new ArrayListMultimap<K, V>(multimap);
}
private ArrayListMultimap() {
super(new HashMap<K, Collection<V>>());
expectedValuesPerKey = DEFAULT_VALUES_PER_KEY;
}
private ArrayListMultimap(int expectedKeys, int expectedValuesPerKey) {
super(Maps.<K, Collection<V>>newHashMapWithExpectedSize(expectedKeys));
checkArgument(expectedValuesPerKey >= 0);
this.expectedValuesPerKey = expectedValuesPerKey;
}
private ArrayListMultimap(Multimap<? extends K, ? extends V> multimap) {
this(multimap.keySet().size(),
(multimap instanceof ArrayListMultimap) ?
((ArrayListMultimap<?, ?>) multimap).expectedValuesPerKey :
DEFAULT_VALUES_PER_KEY);
putAll(multimap);
}
/**
* Creates a new, empty {@code ArrayList} to hold the collection of values for
* an arbitrary key.
*/
@Override List<V> createCollection() {
return new ArrayList<V>(expectedValuesPerKey);
}
/**
* Reduces the memory used by this {@code ArrayListMultimap}, if feasible.
*/
public void trimToSize() {
for (Collection<V> collection : backingMap().values()) {
ArrayList<V> arrayList = (ArrayList<V>) collection;
arrayList.trimToSize();
}
}
}
| Java |
/*
* Copyright (C) 2009 The Guava Authors
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package com.google.common.collect;
import static com.google.common.base.Preconditions.checkNotNull;
import java.util.Collections;
/**
* GWT emulation of {@link SingletonImmutableSet}.
*
* @author Hayward Chan
*/
final class SingletonImmutableSet<E> extends ImmutableSet<E> {
// This reference is used both by the custom field serializer, and by the
// GWT compiler to infer the elements of the lists that needs to be
// serialized.
//
// Although this reference is non-final, it doesn't change after set creation.
E element;
SingletonImmutableSet(E element) {
super(Collections.singleton(checkNotNull(element)));
this.element = element;
}
}
| Java |
/*
* Copyright (C) 2011 The Guava Authors
*
* Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except
* in compliance with the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software distributed under the License
* is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express
* or implied. See the License for the specific language governing permissions and limitations under
* the License.
*/
package com.google.common.collect;
import com.google.common.annotations.GwtCompatible;
import java.util.NoSuchElementException;
import java.util.Set;
import javax.annotation.Nullable;
/**
* An empty contiguous set.
*
* @author Gregory Kick
*/
@GwtCompatible(emulated = true)
@SuppressWarnings("unchecked") // allow ungenerified Comparable types
final class EmptyContiguousSet<C extends Comparable> extends ContiguousSet<C> {
EmptyContiguousSet(DiscreteDomain<C> domain) {
super(domain);
}
@Override public C first() {
throw new NoSuchElementException();
}
@Override public C last() {
throw new NoSuchElementException();
}
@Override public int size() {
return 0;
}
@Override public ContiguousSet<C> intersection(ContiguousSet<C> other) {
return this;
}
@Override public Range<C> range() {
throw new NoSuchElementException();
}
@Override public Range<C> range(BoundType lowerBoundType, BoundType upperBoundType) {
throw new NoSuchElementException();
}
@Override ContiguousSet<C> headSetImpl(C toElement, boolean inclusive) {
return this;
}
@Override ContiguousSet<C> subSetImpl(
C fromElement, boolean fromInclusive, C toElement, boolean toInclusive) {
return this;
}
@Override ContiguousSet<C> tailSetImpl(C fromElement, boolean fromInclusive) {
return this;
}
//Abstract method doesn't exist in GWT emulation
/* @Override */ int indexOf(Object target) {
return -1;
}
@Override public UnmodifiableIterator<C> iterator() {
return Iterators.emptyIterator();
}
@Override boolean isPartialView() {
return false;
}
@Override public boolean isEmpty() {
return true;
}
@Override public ImmutableList<C> asList() {
return ImmutableList.of();
}
@Override public String toString() {
return "[]";
}
@Override public boolean equals(@Nullable Object object) {
if (object instanceof Set) {
Set<?> that = (Set<?>) object;
return that.isEmpty();
}
return false;
}
@Override public int hashCode() {
return 0;
}
}
| Java |
/*
* Copyright (C) 2007 The Guava Authors
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package com.google.common.collect;
import com.google.common.annotations.GwtCompatible;
import java.util.HashMap;
import java.util.Map;
import javax.annotation.Nullable;
/**
* A {@link BiMap} backed by two {@link HashMap} instances. This implementation
* allows null keys and values. A {@code HashBiMap} and its inverse are both
* serializable.
*
* <p>See the Guava User Guide article on <a href=
* "http://code.google.com/p/guava-libraries/wiki/NewCollectionTypesExplained#BiMap">
* {@code BiMap}</a>.
*
* @author Mike Bostock
* @since 2.0 (imported from Google Collections Library)
*/
@GwtCompatible(emulated = true)
public final class HashBiMap<K, V> extends AbstractBiMap<K, V> {
/**
* Returns a new, empty {@code HashBiMap} with the default initial capacity
* (16).
*/
public static <K, V> HashBiMap<K, V> create() {
return new HashBiMap<K, V>();
}
/**
* Constructs a new, empty bimap with the specified expected size.
*
* @param expectedSize the expected number of entries
* @throws IllegalArgumentException if the specified expected size is
* negative
*/
public static <K, V> HashBiMap<K, V> create(int expectedSize) {
return new HashBiMap<K, V>(expectedSize);
}
/**
* Constructs a new bimap containing initial values from {@code map}. The
* bimap is created with an initial capacity sufficient to hold the mappings
* in the specified map.
*/
public static <K, V> HashBiMap<K, V> create(
Map<? extends K, ? extends V> map) {
HashBiMap<K, V> bimap = create(map.size());
bimap.putAll(map);
return bimap;
}
private HashBiMap() {
super(new HashMap<K, V>(), new HashMap<V, K>());
}
private HashBiMap(int expectedSize) {
super(
Maps.<K, V>newHashMapWithExpectedSize(expectedSize),
Maps.<V, K>newHashMapWithExpectedSize(expectedSize));
}
// Override these two methods to show that keys and values may be null
@Override public V put(@Nullable K key, @Nullable V value) {
return super.put(key, value);
}
@Override public V forcePut(@Nullable K key, @Nullable V value) {
return super.forcePut(key, value);
}
}
| Java |
/*
* Copyright (C) 2009 The Guava Authors
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package com.google.common.collect;
import java.util.Comparator;
/**
* GWT emulation of {@link EmptyImmutableSortedSet}.
*
* @author Hayward Chan
*/
class EmptyImmutableSortedSet<E> extends ImmutableSortedSet<E> {
EmptyImmutableSortedSet(Comparator<? super E> comparator) {
super(comparator);
}
}
| Java |
/*
* Copyright (C) 2007 The Guava Authors
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package com.google.common.collect;
import com.google.common.annotations.GwtCompatible;
import com.google.common.annotations.VisibleForTesting;
import com.google.common.base.Preconditions;
import java.util.Collection;
import java.util.HashMap;
import java.util.Set;
/**
* Implementation of {@link Multimap} using hash tables.
*
* <p>The multimap does not store duplicate key-value pairs. Adding a new
* key-value pair equal to an existing key-value pair has no effect.
*
* <p>Keys and values may be null. All optional multimap methods are supported,
* and all returned views are modifiable.
*
* <p>This class is not threadsafe when any concurrent operations update the
* multimap. Concurrent read operations will work correctly. To allow concurrent
* update operations, wrap your multimap with a call to {@link
* Multimaps#synchronizedSetMultimap}.
*
* @author Jared Levy
* @since 2.0 (imported from Google Collections Library)
*/
@GwtCompatible(serializable = true, emulated = true)
public final class HashMultimap<K, V> extends AbstractSetMultimap<K, V> {
private static final int DEFAULT_VALUES_PER_KEY = 8;
@VisibleForTesting
transient int expectedValuesPerKey = DEFAULT_VALUES_PER_KEY;
/**
* Creates a new, empty {@code HashMultimap} with the default initial
* capacities.
*/
public static <K, V> HashMultimap<K, V> create() {
return new HashMultimap<K, V>();
}
/**
* Constructs an empty {@code HashMultimap} with enough capacity to hold the
* specified numbers of keys and values without rehashing.
*
* @param expectedKeys the expected number of distinct keys
* @param expectedValuesPerKey the expected average number of values per key
* @throws IllegalArgumentException if {@code expectedKeys} or {@code
* expectedValuesPerKey} is negative
*/
public static <K, V> HashMultimap<K, V> create(
int expectedKeys, int expectedValuesPerKey) {
return new HashMultimap<K, V>(expectedKeys, expectedValuesPerKey);
}
/**
* Constructs a {@code HashMultimap} with the same mappings as the specified
* multimap. If a key-value mapping appears multiple times in the input
* multimap, it only appears once in the constructed multimap.
*
* @param multimap the multimap whose contents are copied to this multimap
*/
public static <K, V> HashMultimap<K, V> create(
Multimap<? extends K, ? extends V> multimap) {
return new HashMultimap<K, V>(multimap);
}
private HashMultimap() {
super(new HashMap<K, Collection<V>>());
}
private HashMultimap(int expectedKeys, int expectedValuesPerKey) {
super(Maps.<K, Collection<V>>newHashMapWithExpectedSize(expectedKeys));
Preconditions.checkArgument(expectedValuesPerKey >= 0);
this.expectedValuesPerKey = expectedValuesPerKey;
}
private HashMultimap(Multimap<? extends K, ? extends V> multimap) {
super(Maps.<K, Collection<V>>newHashMapWithExpectedSize(
multimap.keySet().size()));
putAll(multimap);
}
/**
* {@inheritDoc}
*
* <p>Creates an empty {@code HashSet} for a collection of values for one key.
*
* @return a new {@code HashSet} containing a collection of values for one key
*/
@Override Set<V> createCollection() {
return Sets.<V>newHashSetWithExpectedSize(expectedValuesPerKey);
}
}
| Java |
/*
* Copyright (C) 2008 The Guava Authors
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package com.google.common.collect;
import static com.google.common.base.Preconditions.checkNotNull;
import com.google.common.annotations.Beta;
import com.google.common.annotations.GwtCompatible;
import java.io.Serializable;
import java.util.Arrays;
import java.util.Collection;
import java.util.Collections;
import java.util.Comparator;
import java.util.Iterator;
import java.util.LinkedHashMap;
import java.util.List;
import java.util.Map.Entry;
import java.util.TreeMap;
import javax.annotation.Nullable;
/**
* An immutable {@link Multimap}. Does not permit null keys or values.
*
* <p>Unlike {@link Multimaps#unmodifiableMultimap(Multimap)}, which is
* a <i>view</i> of a separate multimap which can still change, an instance of
* {@code ImmutableMultimap} contains its own data and will <i>never</i>
* change. {@code ImmutableMultimap} is convenient for
* {@code public static final} multimaps ("constant multimaps") and also lets
* you easily make a "defensive copy" of a multimap provided to your class by
* a caller.
*
* <p><b>Note:</b> Although this class is not final, it cannot be subclassed as
* it has no public or protected constructors. Thus, instances of this class
* are guaranteed to be immutable.
*
* <p>In addition to methods defined by {@link Multimap}, an {@link #inverse}
* method is also supported.
*
* <p>See the Guava User Guide article on <a href=
* "http://code.google.com/p/guava-libraries/wiki/ImmutableCollectionsExplained">
* immutable collections</a>.
*
* @author Jared Levy
* @since 2.0 (imported from Google Collections Library)
*/
@GwtCompatible(emulated = true)
// TODO(user): If BiMultimap graduates from labs, this class should implement it.
public abstract class ImmutableMultimap<K, V>
implements Multimap<K, V>, Serializable {
/** Returns an empty multimap. */
public static <K, V> ImmutableMultimap<K, V> of() {
return ImmutableListMultimap.of();
}
/**
* Returns an immutable multimap containing a single entry.
*/
public static <K, V> ImmutableMultimap<K, V> of(K k1, V v1) {
return ImmutableListMultimap.of(k1, v1);
}
/**
* Returns an immutable multimap containing the given entries, in order.
*/
public static <K, V> ImmutableMultimap<K, V> of(K k1, V v1, K k2, V v2) {
return ImmutableListMultimap.of(k1, v1, k2, v2);
}
/**
* Returns an immutable multimap containing the given entries, in order.
*/
public static <K, V> ImmutableMultimap<K, V> of(
K k1, V v1, K k2, V v2, K k3, V v3) {
return ImmutableListMultimap.of(k1, v1, k2, v2, k3, v3);
}
/**
* Returns an immutable multimap containing the given entries, in order.
*/
public static <K, V> ImmutableMultimap<K, V> of(
K k1, V v1, K k2, V v2, K k3, V v3, K k4, V v4) {
return ImmutableListMultimap.of(k1, v1, k2, v2, k3, v3, k4, v4);
}
/**
* Returns an immutable multimap containing the given entries, in order.
*/
public static <K, V> ImmutableMultimap<K, V> of(
K k1, V v1, K k2, V v2, K k3, V v3, K k4, V v4, K k5, V v5) {
return ImmutableListMultimap.of(k1, v1, k2, v2, k3, v3, k4, v4, k5, v5);
}
// looking for of() with > 5 entries? Use the builder instead.
/**
* Returns a new builder. The generated builder is equivalent to the builder
* created by the {@link Builder} constructor.
*/
public static <K, V> Builder<K, V> builder() {
return new Builder<K, V>();
}
/**
* Multimap for {@link ImmutableMultimap.Builder} that maintains key and
* value orderings, allows duplicate values, and performs better than
* {@link LinkedListMultimap}.
*/
private static class BuilderMultimap<K, V> extends AbstractMultimap<K, V> {
BuilderMultimap() {
super(new LinkedHashMap<K, Collection<V>>());
}
@Override Collection<V> createCollection() {
return Lists.newArrayList();
}
private static final long serialVersionUID = 0;
}
/**
* Multimap for {@link ImmutableMultimap.Builder} that sorts key and allows
* duplicate values,
*/
private static class SortedKeyBuilderMultimap<K, V>
extends AbstractMultimap<K, V> {
SortedKeyBuilderMultimap(
Comparator<? super K> keyComparator, Multimap<K, V> multimap) {
super(new TreeMap<K, Collection<V>>(keyComparator));
putAll(multimap);
}
@Override Collection<V> createCollection() {
return Lists.newArrayList();
}
private static final long serialVersionUID = 0;
}
/**
* A builder for creating immutable multimap instances, especially
* {@code public static final} multimaps ("constant multimaps"). Example:
* <pre> {@code
*
* static final Multimap<String, Integer> STRING_TO_INTEGER_MULTIMAP =
* new ImmutableMultimap.Builder<String, Integer>()
* .put("one", 1)
* .putAll("several", 1, 2, 3)
* .putAll("many", 1, 2, 3, 4, 5)
* .build();}</pre>
*
* Builder instances can be reused; it is safe to call {@link #build} multiple
* times to build multiple multimaps in series. Each multimap contains the
* key-value mappings in the previously created multimaps.
*
* @since 2.0 (imported from Google Collections Library)
*/
public static class Builder<K, V> {
Multimap<K, V> builderMultimap = new BuilderMultimap<K, V>();
Comparator<? super V> valueComparator;
/**
* Creates a new builder. The returned builder is equivalent to the builder
* generated by {@link ImmutableMultimap#builder}.
*/
public Builder() {}
/**
* Adds a key-value mapping to the built multimap.
*/
public Builder<K, V> put(K key, V value) {
builderMultimap.put(checkNotNull(key), checkNotNull(value));
return this;
}
/**
* Adds an entry to the built multimap.
*
* @since 11.0
*/
public Builder<K, V> put(Entry<? extends K, ? extends V> entry) {
builderMultimap.put(
checkNotNull(entry.getKey()), checkNotNull(entry.getValue()));
return this;
}
/**
* Stores a collection of values with the same key in the built multimap.
*
* @throws NullPointerException if {@code key}, {@code values}, or any
* element in {@code values} is null. The builder is left in an invalid
* state.
*/
public Builder<K, V> putAll(K key, Iterable<? extends V> values) {
Collection<V> valueList = builderMultimap.get(checkNotNull(key));
for (V value : values) {
valueList.add(checkNotNull(value));
}
return this;
}
/**
* Stores an array of values with the same key in the built multimap.
*
* @throws NullPointerException if the key or any value is null. The builder
* is left in an invalid state.
*/
public Builder<K, V> putAll(K key, V... values) {
return putAll(key, Arrays.asList(values));
}
/**
* Stores another multimap's entries in the built multimap. The generated
* multimap's key and value orderings correspond to the iteration ordering
* of the {@code multimap.asMap()} view, with new keys and values following
* any existing keys and values.
*
* @throws NullPointerException if any key or value in {@code multimap} is
* null. The builder is left in an invalid state.
*/
public Builder<K, V> putAll(Multimap<? extends K, ? extends V> multimap) {
for (Entry<? extends K, ? extends Collection<? extends V>> entry
: multimap.asMap().entrySet()) {
putAll(entry.getKey(), entry.getValue());
}
return this;
}
/**
* Specifies the ordering of the generated multimap's keys.
*
* @since 8.0
*/
@Beta
public Builder<K, V> orderKeysBy(Comparator<? super K> keyComparator) {
builderMultimap = new SortedKeyBuilderMultimap<K, V>(
checkNotNull(keyComparator), builderMultimap);
return this;
}
/**
* Specifies the ordering of the generated multimap's values for each key.
*
* @since 8.0
*/
@Beta
public Builder<K, V> orderValuesBy(Comparator<? super V> valueComparator) {
this.valueComparator = checkNotNull(valueComparator);
return this;
}
/**
* Returns a newly-created immutable multimap.
*/
public ImmutableMultimap<K, V> build() {
if (valueComparator != null) {
for (Collection<V> values : builderMultimap.asMap().values()) {
List<V> list = (List <V>) values;
Collections.sort(list, valueComparator);
}
}
return copyOf(builderMultimap);
}
}
/**
* Returns an immutable multimap containing the same mappings as {@code
* multimap}. The generated multimap's key and value orderings correspond to
* the iteration ordering of the {@code multimap.asMap()} view.
*
* <p>Despite the method name, this method attempts to avoid actually copying
* the data when it is safe to do so. The exact circumstances under which a
* copy will or will not be performed are undocumented and subject to change.
*
* @throws NullPointerException if any key or value in {@code multimap} is
* null
*/
public static <K, V> ImmutableMultimap<K, V> copyOf(
Multimap<? extends K, ? extends V> multimap) {
if (multimap instanceof ImmutableMultimap) {
@SuppressWarnings("unchecked") // safe since multimap is not writable
ImmutableMultimap<K, V> kvMultimap
= (ImmutableMultimap<K, V>) multimap;
if (!kvMultimap.isPartialView()) {
return kvMultimap;
}
}
return ImmutableListMultimap.copyOf(multimap);
}
final transient ImmutableMap<K, ? extends ImmutableCollection<V>> map;
final transient int size;
// These constants allow the deserialization code to set final fields. This
// holder class makes sure they are not initialized unless an instance is
// deserialized.
ImmutableMultimap(ImmutableMap<K, ? extends ImmutableCollection<V>> map,
int size) {
this.map = map;
this.size = size;
}
// mutators (not supported)
/**
* Guaranteed to throw an exception and leave the multimap unmodified.
*
* @throws UnsupportedOperationException always
*/
@Override
public ImmutableCollection<V> removeAll(Object key) {
throw new UnsupportedOperationException();
}
/**
* Guaranteed to throw an exception and leave the multimap unmodified.
*
* @throws UnsupportedOperationException always
*/
@Override
public ImmutableCollection<V> replaceValues(K key,
Iterable<? extends V> values) {
throw new UnsupportedOperationException();
}
/**
* Guaranteed to throw an exception and leave the multimap unmodified.
*
* @throws UnsupportedOperationException always
*/
@Override
public void clear() {
throw new UnsupportedOperationException();
}
/**
* Returns an immutable collection of the values for the given key. If no
* mappings in the multimap have the provided key, an empty immutable
* collection is returned. The values are in the same order as the parameters
* used to build this multimap.
*/
@Override
public abstract ImmutableCollection<V> get(K key);
/**
* Returns an immutable multimap which is the inverse of this one. For every
* key-value mapping in the original, the result will have a mapping with
* key and value reversed.
*
* @since 11
*/
@Beta
public abstract ImmutableMultimap<V, K> inverse();
/**
* Guaranteed to throw an exception and leave the multimap unmodified.
*
* @throws UnsupportedOperationException always
*/
@Override
public boolean put(K key, V value) {
throw new UnsupportedOperationException();
}
/**
* Guaranteed to throw an exception and leave the multimap unmodified.
*
* @throws UnsupportedOperationException always
*/
@Override
public boolean putAll(K key, Iterable<? extends V> values) {
throw new UnsupportedOperationException();
}
/**
* Guaranteed to throw an exception and leave the multimap unmodified.
*
* @throws UnsupportedOperationException always
*/
@Override
public boolean putAll(Multimap<? extends K, ? extends V> multimap) {
throw new UnsupportedOperationException();
}
/**
* Guaranteed to throw an exception and leave the multimap unmodified.
*
* @throws UnsupportedOperationException always
*/
@Override
public boolean remove(Object key, Object value) {
throw new UnsupportedOperationException();
}
boolean isPartialView(){
return map.isPartialView();
}
// accessors
@Override
public boolean containsEntry(@Nullable Object key, @Nullable Object value) {
Collection<V> values = map.get(key);
return values != null && values.contains(value);
}
@Override
public boolean containsKey(@Nullable Object key) {
return map.containsKey(key);
}
@Override
public boolean containsValue(@Nullable Object value) {
for (Collection<V> valueCollection : map.values()) {
if (valueCollection.contains(value)) {
return true;
}
}
return false;
}
@Override
public boolean isEmpty() {
return size == 0;
}
@Override
public int size() {
return size;
}
@Override public boolean equals(@Nullable Object object) {
if (object instanceof Multimap) {
Multimap<?, ?> that = (Multimap<?, ?>) object;
return this.map.equals(that.asMap());
}
return false;
}
@Override public int hashCode() {
return map.hashCode();
}
@Override public String toString() {
return map.toString();
}
// views
/**
* Returns an immutable set of the distinct keys in this multimap. These keys
* are ordered according to when they first appeared during the construction
* of this multimap.
*/
@Override
public ImmutableSet<K> keySet() {
return map.keySet();
}
/**
* Returns an immutable map that associates each key with its corresponding
* values in the multimap.
*/
@Override
@SuppressWarnings("unchecked") // a widening cast
public ImmutableMap<K, Collection<V>> asMap() {
return (ImmutableMap) map;
}
private transient ImmutableCollection<Entry<K, V>> entries;
/**
* Returns an immutable collection of all key-value pairs in the multimap. Its
* iterator traverses the values for the first key, the values for the second
* key, and so on.
*/
@Override
public ImmutableCollection<Entry<K, V>> entries() {
ImmutableCollection<Entry<K, V>> result = entries;
return (result == null)
? (entries = new EntryCollection<K, V>(this)) : result;
}
private static class EntryCollection<K, V>
extends ImmutableCollection<Entry<K, V>> {
final ImmutableMultimap<K, V> multimap;
EntryCollection(ImmutableMultimap<K, V> multimap) {
this.multimap = multimap;
}
@Override public UnmodifiableIterator<Entry<K, V>> iterator() {
final Iterator<? extends Entry<K, ? extends ImmutableCollection<V>>>
mapIterator = this.multimap.map.entrySet().iterator();
return new UnmodifiableIterator<Entry<K, V>>() {
K key;
Iterator<V> valueIterator;
@Override
public boolean hasNext() {
return (key != null && valueIterator.hasNext())
|| mapIterator.hasNext();
}
@Override
public Entry<K, V> next() {
if (key == null || !valueIterator.hasNext()) {
Entry<K, ? extends ImmutableCollection<V>> entry
= mapIterator.next();
key = entry.getKey();
valueIterator = entry.getValue().iterator();
}
return Maps.immutableEntry(key, valueIterator.next());
}
};
}
@Override boolean isPartialView() {
return multimap.isPartialView();
}
@Override
public int size() {
return multimap.size();
}
@Override public boolean contains(Object object) {
if (object instanceof Entry) {
Entry<?, ?> entry = (Entry<?, ?>) object;
return multimap.containsEntry(entry.getKey(), entry.getValue());
}
return false;
}
private static final long serialVersionUID = 0;
}
private transient ImmutableMultiset<K> keys;
/**
* Returns a collection, which may contain duplicates, of all keys. The number
* of times a key appears in the returned multiset equals the number of
* mappings the key has in the multimap. Duplicate keys appear consecutively
* in the multiset's iteration order.
*/
@Override
public ImmutableMultiset<K> keys() {
ImmutableMultiset<K> result = keys;
return (result == null) ? (keys = createKeys()) : result;
}
private ImmutableMultiset<K> createKeys() {
ImmutableMultiset.Builder<K> builder = ImmutableMultiset.builder();
for (Entry<K, ? extends ImmutableCollection<V>> entry
: map.entrySet()) {
builder.addCopies(entry.getKey(), entry.getValue().size());
}
return builder.build();
}
private transient ImmutableCollection<V> values;
/**
* Returns an immutable collection of the values in this multimap. Its
* iterator traverses the values for the first key, the values for the second
* key, and so on.
*/
@Override
public ImmutableCollection<V> values() {
ImmutableCollection<V> result = values;
return (result == null) ? (values = new Values<V>(this)) : result;
}
private static class Values<V> extends ImmutableCollection<V> {
final ImmutableMultimap<?, V> multimap;
Values(ImmutableMultimap<?, V> multimap) {
this.multimap = multimap;
}
@Override public UnmodifiableIterator<V> iterator() {
final Iterator<? extends Entry<?, V>> entryIterator
= multimap.entries().iterator();
return new UnmodifiableIterator<V>() {
@Override
public boolean hasNext() {
return entryIterator.hasNext();
}
@Override
public V next() {
return entryIterator.next().getValue();
}
};
}
@Override
public int size() {
return multimap.size();
}
@Override boolean isPartialView() {
return true;
}
private static final long serialVersionUID = 0;
}
private static final long serialVersionUID = 0;
}
| Java |
/*
* Copyright (C) 2009 The Guava Authors
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package com.google.common.collect;
import static com.google.common.base.Preconditions.checkArgument;
import static com.google.common.base.Preconditions.checkNotNull;
import com.google.common.collect.ImmutableSortedSet;
import java.util.Collections;
import java.util.Comparator;
import java.util.Iterator;
import java.util.Map;
import java.util.SortedMap;
/**
* GWT emulated version of {@link ImmutableSortedMap}. It's a thin wrapper
* around a {@link java.util.TreeMap}.
*
* @author Hayward Chan
*/
public class ImmutableSortedMap<K, V>
extends ImmutableMap<K, V> implements SortedMap<K, V> {
// TODO: Confirm that ImmutableSortedMap is faster to construct and uses less
// memory than TreeMap; then say so in the class Javadoc.
// TODO: Create separate subclasses for empty, single-entry, and
// multiple-entry instances.
@SuppressWarnings("unchecked")
private static final Comparator NATURAL_ORDER = Ordering.natural();
@SuppressWarnings("unchecked")
private static final ImmutableSortedMap<Object, Object> NATURAL_EMPTY_MAP
= create(NATURAL_ORDER);
// This reference is only used by GWT compiler to infer the keys and values
// of the map that needs to be serialized.
private Comparator<K> unusedComparatorForSerialization;
private K unusedKeyForSerialization;
private V unusedValueForSerialization;
private transient final SortedMap<K, V> sortedDelegate;
// The comparator used by this map. It's the same as that of sortedDelegate,
// except that when sortedDelegate's comparator is null, it points to a
// non-null instance of Ordering.natural().
private transient final Comparator<K> comparator;
// If map has a null comparator, the keys should have a natural ordering,
// even though K doesn't explicitly implement Comparable.
@SuppressWarnings("unchecked")
ImmutableSortedMap(SortedMap<K, ? extends V> delegate) {
super(delegate);
this.comparator = (delegate.comparator() == null)
? NATURAL_ORDER : delegate.comparator();
this.sortedDelegate = Collections.unmodifiableSortedMap(delegate);
}
private static <K, V> ImmutableSortedMap<K, V> create(
Comparator<? super K> comparator,
Entry<? extends K, ? extends V>... entries) {
checkNotNull(comparator);
SortedMap<K, V> delegate = Maps.newTreeMap(comparator);
for (Entry<? extends K, ? extends V> entry : entries) {
delegate.put(entry.getKey(), entry.getValue());
}
return new ImmutableSortedMap<K, V>(delegate);
}
// Casting to any type is safe because the set will never hold any elements.
@SuppressWarnings("unchecked")
public static <K, V> ImmutableSortedMap<K, V> of() {
return (ImmutableSortedMap) NATURAL_EMPTY_MAP;
}
public static <K extends Comparable<? super K>, V> ImmutableSortedMap<K, V>
of(K k1, V v1) {
return create(Ordering.natural(), entryOf(k1, v1));
}
public static <K extends Comparable<? super K>, V> ImmutableSortedMap<K, V>
of(K k1, V v1, K k2, V v2) {
return new Builder<K, V>(Ordering.natural())
.put(k1, v1).put(k2, v2).build();
}
public static <K extends Comparable<? super K>, V> ImmutableSortedMap<K, V>
of(K k1, V v1, K k2, V v2, K k3, V v3) {
return new Builder<K, V>(Ordering.natural())
.put(k1, v1).put(k2, v2).put(k3, v3).build();
}
public static <K extends Comparable<? super K>, V> ImmutableSortedMap<K, V>
of(K k1, V v1, K k2, V v2, K k3, V v3, K k4, V v4) {
return new Builder<K, V>(Ordering.natural())
.put(k1, v1).put(k2, v2).put(k3, v3).put(k4, v4).build();
}
public static <K extends Comparable<? super K>, V> ImmutableSortedMap<K, V>
of(K k1, V v1, K k2, V v2, K k3, V v3, K k4, V v4, K k5, V v5) {
return new Builder<K, V>(Ordering.natural())
.put(k1, v1).put(k2, v2).put(k3, v3).put(k4, v4).put(k5, v5).build();
}
public static <K extends Comparable<? super K>, V> ImmutableSortedMap<K, V>
copyOf(Map<? extends K, ? extends V> map) {
return copyOfInternal(map, Ordering.natural());
}
public static <K, V> ImmutableSortedMap<K, V> copyOf(
Map<? extends K, ? extends V> map, Comparator<? super K> comparator) {
return copyOfInternal(map, checkNotNull(comparator));
}
public static <K, V> ImmutableSortedMap<K, V> copyOfSorted(
SortedMap<K, ? extends V> map) {
// If map has a null comparator, the keys should have a natural ordering,
// even though K doesn't explicitly implement Comparable.
@SuppressWarnings("unchecked")
Comparator<? super K> comparator =
(map.comparator() == null) ? NATURAL_ORDER : map.comparator();
return copyOfInternal(map, comparator);
}
private static <K, V> ImmutableSortedMap<K, V> copyOfInternal(
Map<? extends K, ? extends V> map, Comparator<? super K> comparator) {
if (map instanceof ImmutableSortedMap) {
// TODO: Prove that this cast is safe, even though
// Collections.unmodifiableSortedMap requires the same key type.
@SuppressWarnings("unchecked")
ImmutableSortedMap<K, V> kvMap = (ImmutableSortedMap<K, V>) map;
Comparator<?> comparator2 = kvMap.comparator();
boolean sameComparator = (comparator2 == null)
? comparator == NATURAL_ORDER
: comparator.equals(comparator2);
if (sameComparator) {
return kvMap;
}
}
SortedMap<K, V> delegate = Maps.newTreeMap(comparator);
for (Entry<? extends K, ? extends V> entry : map.entrySet()) {
putEntryWithChecks(delegate, entry);
}
return new ImmutableSortedMap<K, V>(delegate);
}
private static <K, V> void putEntryWithChecks(
SortedMap<K, V> map, Entry<? extends K, ? extends V> entry) {
K key = checkNotNull(entry.getKey());
V value = checkNotNull(entry.getValue());
if (map.containsKey(key)) {
// When a collision happens, the colliding entry is the first entry
// of the tail map.
Entry<K, V> previousEntry
= map.tailMap(key).entrySet().iterator().next();
throw new IllegalArgumentException(
"Duplicate keys in mappings " + previousEntry.getKey() +
"=" + previousEntry.getValue() + " and " + key +
"=" + value);
}
map.put(key, value);
}
public static <K extends Comparable<K>, V> Builder<K, V> naturalOrder() {
return new Builder<K, V>(Ordering.natural());
}
public static <K, V> Builder<K, V> orderedBy(Comparator<K> comparator) {
return new Builder<K, V>(comparator);
}
public static <K extends Comparable<K>, V> Builder<K, V> reverseOrder() {
return new Builder<K, V>(Ordering.natural().reverse());
}
public static final class Builder<K, V> extends ImmutableMap.Builder<K, V> {
private final Comparator<? super K> comparator;
public Builder(Comparator<? super K> comparator) {
this.comparator = checkNotNull(comparator);
}
@Override public Builder<K, V> put(K key, V value) {
entries.add(entryOf(key, value));
return this;
}
@Override public Builder<K, V> put(Entry<? extends K, ? extends V> entry) {
super.put(entry);
return this;
}
@Override public Builder<K, V> putAll(Map<? extends K, ? extends V> map) {
for (Entry<? extends K, ? extends V> entry : map.entrySet()) {
put(entry.getKey(), entry.getValue());
}
return this;
}
@Override public ImmutableSortedMap<K, V> build() {
SortedMap<K, V> delegate = Maps.newTreeMap(comparator);
for (Entry<? extends K, ? extends V> entry : entries) {
putEntryWithChecks(delegate, entry);
}
return new ImmutableSortedMap<K, V>(delegate);
}
}
private transient ImmutableSortedSet<K> keySet;
@Override public ImmutableSortedSet<K> keySet() {
ImmutableSortedSet<K> ks = keySet;
return (ks == null) ? (keySet = createKeySet()) : ks;
}
private ImmutableSortedSet<K> createKeySet() {
// the keySet() of the delegate is only a Set and TreeMap.navigatableKeySet
// is not available in GWT yet. To keep the code simple and code size more,
// we make a copy here, instead of creating a view of it.
//
// TODO: revisit if it's unbearably slow or when GWT supports
// TreeMap.navigatbleKeySet().
return ImmutableSortedSet.copyOf(comparator, sortedDelegate.keySet());
}
public Comparator<? super K> comparator() {
return comparator;
}
public K firstKey() {
return sortedDelegate.firstKey();
}
public K lastKey() {
return sortedDelegate.lastKey();
}
K higher(K k) {
Iterator<K> iterator = keySet().tailSet(k).iterator();
while (iterator.hasNext()) {
K tmp = iterator.next();
if (comparator().compare(k, tmp) < 0) {
return tmp;
}
}
return null;
}
public ImmutableSortedMap<K, V> headMap(K toKey) {
checkNotNull(toKey);
return new ImmutableSortedMap<K, V>(sortedDelegate.headMap(toKey));
}
ImmutableSortedMap<K, V> headMap(K toKey, boolean inclusive) {
checkNotNull(toKey);
if (inclusive) {
K tmp = higher(toKey);
if (tmp == null) {
return this;
}
toKey = tmp;
}
return headMap(toKey);
}
public ImmutableSortedMap<K, V> subMap(K fromKey, K toKey) {
checkNotNull(fromKey);
checkNotNull(toKey);
checkArgument(comparator.compare(fromKey, toKey) <= 0);
return new ImmutableSortedMap<K, V>(sortedDelegate.subMap(fromKey, toKey));
}
ImmutableSortedMap<K, V> subMap(K fromKey, boolean fromInclusive, K toKey, boolean toInclusive){
checkNotNull(fromKey);
checkNotNull(toKey);
checkArgument(comparator.compare(fromKey, toKey) <= 0);
return tailMap(fromKey, fromInclusive).headMap(toKey, toInclusive);
}
public ImmutableSortedMap<K, V> tailMap(K fromKey) {
checkNotNull(fromKey);
return new ImmutableSortedMap<K, V>(sortedDelegate.tailMap(fromKey));
}
public ImmutableSortedMap<K, V> tailMap(K fromKey, boolean inclusive) {
checkNotNull(fromKey);
if (!inclusive) {
fromKey = higher(fromKey);
if (fromKey == null) {
return emptyMap(comparator());
}
}
return tailMap(fromKey);
}
static <K, V> ImmutableSortedMap<K, V> emptyMap(Comparator<? super K> comparator) {
if (comparator == NATURAL_ORDER) {
return (ImmutableSortedMap) NATURAL_EMPTY_MAP;
}
return create(comparator);
}
}
| Java |
/*
* Copyright (C) 2011 The Guava Authors
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package com.google.common.testing;
import static com.google.common.base.Preconditions.checkNotNull;
/**
* Methods factored out so that they can be emulated differently in GWT.
*
* @author Chris Povirk
*/
final class Platform {
/**
* Serializes and deserializes the specified object (a no-op under GWT).
*/
@SuppressWarnings("unchecked")
static <T> T reserialize(T object) {
return checkNotNull(object);
}
private Platform() {}
}
| Java |
/*
* Copyright (C) 2011 Google Inc.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package java.util.concurrent;
/**
* Emulation of Callable.
*
* @author Charles Fry
*/
public interface Callable<V> {
V call() throws Exception;
}
| Java |
/*
* Copyright (C) 2011 Google Inc.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package java.util.concurrent;
/**
* Emulation of ExecutionException.
*
* @author fry@google.com (Charles Fry)
*/
public class ExecutionException extends Exception {
protected ExecutionException() { }
protected ExecutionException(String message) {
super(message);
}
public ExecutionException(String message, Throwable cause) {
super(message, cause);
}
public ExecutionException(Throwable cause) {
super(cause);
}
}
| Java |
/*
* Copyright (C) 2009 Google Inc.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package java.util.concurrent;
import java.util.Map;
/**
* Minimal GWT emulation of a map providing atomic operations.
*
* @author Jesse Wilson
*/
public interface ConcurrentMap<K, V> extends Map<K, V> {
V putIfAbsent(K key, V value);
boolean remove(Object key, Object value);
V replace(K key, V value);
boolean replace(K key, V oldValue, V newValue);
}
| Java |
/*
* Copyright (C) 2011 Google Inc.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package java.util.concurrent.atomic;
/**
* GWT emulated version of {@link AtomicLong}. It's a thin wrapper
* around the primitive {@code long}.
*
* @author Jige Yu
*/
public class AtomicLong extends Number implements java.io.Serializable {
private long value;
public AtomicLong(long initialValue) {
this.value = initialValue;
}
public AtomicLong() {
}
public final long get() {
return value;
}
public final void set(long newValue) {
value = newValue;
}
public final void lazySet(long newValue) {
set(newValue);
}
public final long getAndSet(long newValue) {
long current = value;
value = newValue;
return current;
}
public final boolean compareAndSet(long expect, long update) {
if (value == expect) {
value = update;
return true;
} else {
return false;
}
}
public final long getAndIncrement() {
return value++;
}
public final long getAndDecrement() {
return value--;
}
public final long getAndAdd(long delta) {
long current = value;
value += delta;
return current;
}
public final long incrementAndGet() {
return ++value;
}
public final long decrementAndGet() {
return --value;
}
public final long addAndGet(long delta) {
value += delta;
return value;
}
@Override public String toString() {
return Long.toString(value);
}
public int intValue() {
return (int) value;
}
public long longValue() {
return value;
}
public float floatValue() {
return (float) value;
}
public double doubleValue() {
return (double) value;
}
}
| Java |
/*
* Copyright (C) 2009 Google Inc.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package java.util.concurrent.atomic;
/**
* GWT emulated version of {@link AtomicInteger}. It's a thin wrapper
* around the primitive {@code int}.
*
* @author Hayward Chan
*/
public class AtomicInteger extends Number implements java.io.Serializable {
private int value;
public AtomicInteger(int initialValue) {
value = initialValue;
}
public AtomicInteger() {
}
public final int get() {
return value;
}
public final void set(int newValue) {
value = newValue;
}
public final void lazySet(int newValue) {
set(newValue);
}
public final int getAndSet(int newValue) {
int current = value;
value = newValue;
return current;
}
public final boolean compareAndSet(int expect, int update) {
if (value == expect) {
value = update;
return true;
} else {
return false;
}
}
public final int getAndIncrement() {
return value++;
}
public final int getAndDecrement() {
return value--;
}
public final int getAndAdd(int delta) {
int current = value;
value += delta;
return current;
}
public final int incrementAndGet() {
return ++value;
}
public final int decrementAndGet() {
return --value;
}
public final int addAndGet(int delta) {
value += delta;
return value;
}
@Override public String toString() {
return Integer.toString(value);
}
public int intValue() {
return value;
}
public long longValue() {
return (long) value;
}
public float floatValue() {
return (float) value;
}
public double doubleValue() {
return (double) value;
}
}
| Java |
/*
* Copyright (C) 2009 Google Inc.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package java.util.concurrent;
import java.util.AbstractMap;
import java.util.Collections;
import java.util.Enumeration;
import java.util.HashMap;
import java.util.Map;
import java.util.Set;
/**
* Minimal emulation of {@link java.util.concurrent.ConcurrentHashMap}.
* Note that javascript intepreter is <a
* href="http://code.google.com/docreader/#p=google-web-toolkit-doc-1-5&t=DevGuideJavaCompatibility">
* single-threaded</a>, it is essentially a {@link java.util.HashMap},
* implementing the new methods introduced by {@link ConcurrentMap}.
*
* @author Hayward Chan
*/
public class ConcurrentHashMap<K, V>
extends AbstractMap<K, V> implements ConcurrentMap<K, V> {
private final Map<K, V> backingMap;
public ConcurrentHashMap() {
this.backingMap = new HashMap<K, V>();
}
public ConcurrentHashMap(int initialCapacity) {
this.backingMap = new HashMap<K, V>(initialCapacity);
}
public ConcurrentHashMap(int initialCapacity, float loadFactor) {
this.backingMap = new HashMap<K, V>(initialCapacity, loadFactor);
}
public ConcurrentHashMap(Map<? extends K, ? extends V> t) {
this.backingMap = new HashMap<K, V>(t);
}
public V putIfAbsent(K key, V value) {
if (!containsKey(key)) {
return put(key, value);
} else {
return get(key);
}
}
public boolean remove(Object key, Object value) {
if (containsKey(key) && get(key).equals(value)) {
remove(key);
return true;
} else {
return false;
}
}
public boolean replace(K key, V oldValue, V newValue) {
if (oldValue == null || newValue == null) {
throw new NullPointerException();
} else if (containsKey(key) && get(key).equals(oldValue)) {
put(key, newValue);
return true;
} else {
return false;
}
}
public V replace(K key, V value) {
if (value == null) {
throw new NullPointerException();
} else if (containsKey(key)) {
return put(key, value);
} else {
return null;
}
}
@Override public boolean containsKey(Object key) {
if (key == null) {
throw new NullPointerException();
}
return backingMap.containsKey(key);
}
@Override public V get(Object key) {
if (key == null) {
throw new NullPointerException();
}
return backingMap.get(key);
}
@Override public V put(K key, V value) {
if (key == null || value == null) {
throw new NullPointerException();
}
return backingMap.put(key, value);
}
@Override public boolean containsValue(Object value) {
if (value == null) {
throw new NullPointerException();
}
return backingMap.containsValue(value);
}
@Override public V remove(Object key) {
if (key == null) {
throw new NullPointerException();
}
return backingMap.remove(key);
}
@Override public Set<Entry<K, V>> entrySet() {
return backingMap.entrySet();
}
public boolean contains(Object value) {
return containsValue(value);
}
public Enumeration<V> elements() {
return Collections.enumeration(values());
}
public Enumeration<K> keys() {
return Collections.enumeration(keySet());
}
}
| Java |
/*
* Written by Doug Lea with assistance from members of JCP JSR-166
* Expert Group and released to the public domain, as explained at
* http://creativecommons.org/publicdomain/zero/1.0/
*/
package java.util.concurrent;
/**
* GWT emulation of TimeUnit, created by removing unsupported operations from
* Doug Lea's public domain version.
*/
public enum TimeUnit {
NANOSECONDS {
public long toNanos(long d) { return d; }
public long toMicros(long d) { return d/(C1/C0); }
public long toMillis(long d) { return d/(C2/C0); }
public long toSeconds(long d) { return d/(C3/C0); }
public long toMinutes(long d) { return d/(C4/C0); }
public long toHours(long d) { return d/(C5/C0); }
public long toDays(long d) { return d/(C6/C0); }
public long convert(long d, TimeUnit u) { return u.toNanos(d); }
int excessNanos(long d, long m) { return (int)(d - (m*C2)); }
},
MICROSECONDS {
public long toNanos(long d) { return x(d, C1/C0, MAX/(C1/C0)); }
public long toMicros(long d) { return d; }
public long toMillis(long d) { return d/(C2/C1); }
public long toSeconds(long d) { return d/(C3/C1); }
public long toMinutes(long d) { return d/(C4/C1); }
public long toHours(long d) { return d/(C5/C1); }
public long toDays(long d) { return d/(C6/C1); }
public long convert(long d, TimeUnit u) { return u.toMicros(d); }
int excessNanos(long d, long m) { return (int)((d*C1) - (m*C2)); }
},
MILLISECONDS {
public long toNanos(long d) { return x(d, C2/C0, MAX/(C2/C0)); }
public long toMicros(long d) { return x(d, C2/C1, MAX/(C2/C1)); }
public long toMillis(long d) { return d; }
public long toSeconds(long d) { return d/(C3/C2); }
public long toMinutes(long d) { return d/(C4/C2); }
public long toHours(long d) { return d/(C5/C2); }
public long toDays(long d) { return d/(C6/C2); }
public long convert(long d, TimeUnit u) { return u.toMillis(d); }
int excessNanos(long d, long m) { return 0; }
},
SECONDS {
public long toNanos(long d) { return x(d, C3/C0, MAX/(C3/C0)); }
public long toMicros(long d) { return x(d, C3/C1, MAX/(C3/C1)); }
public long toMillis(long d) { return x(d, C3/C2, MAX/(C3/C2)); }
public long toSeconds(long d) { return d; }
public long toMinutes(long d) { return d/(C4/C3); }
public long toHours(long d) { return d/(C5/C3); }
public long toDays(long d) { return d/(C6/C3); }
public long convert(long d, TimeUnit u) { return u.toSeconds(d); }
int excessNanos(long d, long m) { return 0; }
},
MINUTES {
public long toNanos(long d) { return x(d, C4/C0, MAX/(C4/C0)); }
public long toMicros(long d) { return x(d, C4/C1, MAX/(C4/C1)); }
public long toMillis(long d) { return x(d, C4/C2, MAX/(C4/C2)); }
public long toSeconds(long d) { return x(d, C4/C3, MAX/(C4/C3)); }
public long toMinutes(long d) { return d; }
public long toHours(long d) { return d/(C5/C4); }
public long toDays(long d) { return d/(C6/C4); }
public long convert(long d, TimeUnit u) { return u.toMinutes(d); }
int excessNanos(long d, long m) { return 0; }
},
HOURS {
public long toNanos(long d) { return x(d, C5/C0, MAX/(C5/C0)); }
public long toMicros(long d) { return x(d, C5/C1, MAX/(C5/C1)); }
public long toMillis(long d) { return x(d, C5/C2, MAX/(C5/C2)); }
public long toSeconds(long d) { return x(d, C5/C3, MAX/(C5/C3)); }
public long toMinutes(long d) { return x(d, C5/C4, MAX/(C5/C4)); }
public long toHours(long d) { return d; }
public long toDays(long d) { return d/(C6/C5); }
public long convert(long d, TimeUnit u) { return u.toHours(d); }
int excessNanos(long d, long m) { return 0; }
},
DAYS {
public long toNanos(long d) { return x(d, C6/C0, MAX/(C6/C0)); }
public long toMicros(long d) { return x(d, C6/C1, MAX/(C6/C1)); }
public long toMillis(long d) { return x(d, C6/C2, MAX/(C6/C2)); }
public long toSeconds(long d) { return x(d, C6/C3, MAX/(C6/C3)); }
public long toMinutes(long d) { return x(d, C6/C4, MAX/(C6/C4)); }
public long toHours(long d) { return x(d, C6/C5, MAX/(C6/C5)); }
public long toDays(long d) { return d; }
public long convert(long d, TimeUnit u) { return u.toDays(d); }
int excessNanos(long d, long m) { return 0; }
};
// Handy constants for conversion methods
static final long C0 = 1L;
static final long C1 = C0 * 1000L;
static final long C2 = C1 * 1000L;
static final long C3 = C2 * 1000L;
static final long C4 = C3 * 60L;
static final long C5 = C4 * 60L;
static final long C6 = C5 * 24L;
static final long MAX = Long.MAX_VALUE;
static long x(long d, long m, long over) {
if (d > over) return Long.MAX_VALUE;
if (d < -over) return Long.MIN_VALUE;
return d * m;
}
// exceptions below changed from AbstractMethodError for GWT
public long convert(long sourceDuration, TimeUnit sourceUnit) {
throw new AssertionError();
}
public long toNanos(long duration) {
throw new AssertionError();
}
public long toMicros(long duration) {
throw new AssertionError();
}
public long toMillis(long duration) {
throw new AssertionError();
}
public long toSeconds(long duration) {
throw new AssertionError();
}
public long toMinutes(long duration) {
throw new AssertionError();
}
public long toHours(long duration) {
throw new AssertionError();
}
public long toDays(long duration) {
throw new AssertionError();
}
abstract int excessNanos(long d, long m);
}
| Java |
/*
* Copyright (C) 2007 The Guava Authors
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package com.google.common.base;
import static com.google.common.base.Preconditions.checkNotNull;
import com.google.common.annotations.Beta;
import com.google.common.annotations.GwtCompatible;
import com.google.common.annotations.GwtIncompatible;
import java.io.Serializable;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Collection;
import java.util.List;
import java.util.regex.Pattern;
import javax.annotation.Nullable;
/**
* Static utility methods pertaining to {@code Predicate} instances.
*
* <p>All methods returns serializable predicates as long as they're given
* serializable parameters.
*
* <p>See the Guava User Guide article on <a href=
* "http://code.google.com/p/guava-libraries/wiki/FunctionalExplained">the use of {@code
* Predicate}</a>.
*
* @author Kevin Bourrillion
* @since 2.0 (imported from Google Collections Library)
*/
@GwtCompatible(emulated = true)
public final class Predicates {
private Predicates() {}
// TODO(kevinb): considering having these implement a VisitablePredicate
// interface which specifies an accept(PredicateVisitor) method.
/**
* Returns a predicate that always evaluates to {@code true}.
*/
@GwtCompatible(serializable = true)
public static <T> Predicate<T> alwaysTrue() {
return ObjectPredicate.ALWAYS_TRUE.withNarrowedType();
}
/**
* Returns a predicate that always evaluates to {@code false}.
*/
@GwtCompatible(serializable = true)
public static <T> Predicate<T> alwaysFalse() {
return ObjectPredicate.ALWAYS_FALSE.withNarrowedType();
}
/**
* Returns a predicate that evaluates to {@code true} if the object reference
* being tested is null.
*/
@GwtCompatible(serializable = true)
public static <T> Predicate<T> isNull() {
return ObjectPredicate.IS_NULL.withNarrowedType();
}
/**
* Returns a predicate that evaluates to {@code true} if the object reference
* being tested is not null.
*/
@GwtCompatible(serializable = true)
public static <T> Predicate<T> notNull() {
return ObjectPredicate.NOT_NULL.withNarrowedType();
}
/**
* Returns a predicate that evaluates to {@code true} if the given predicate
* evaluates to {@code false}.
*/
public static <T> Predicate<T> not(Predicate<T> predicate) {
return new NotPredicate<T>(predicate);
}
/**
* Returns a predicate that evaluates to {@code true} if each of its
* components evaluates to {@code true}. The components are evaluated in
* order, and evaluation will be "short-circuited" as soon as a false
* predicate is found. It defensively copies the iterable passed in, so future
* changes to it won't alter the behavior of this predicate. If {@code
* components} is empty, the returned predicate will always evaluate to {@code
* true}.
*/
public static <T> Predicate<T> and(
Iterable<? extends Predicate<? super T>> components) {
return new AndPredicate<T>(defensiveCopy(components));
}
/**
* Returns a predicate that evaluates to {@code true} if each of its
* components evaluates to {@code true}. The components are evaluated in
* order, and evaluation will be "short-circuited" as soon as a false
* predicate is found. It defensively copies the array passed in, so future
* changes to it won't alter the behavior of this predicate. If {@code
* components} is empty, the returned predicate will always evaluate to {@code
* true}.
*/
public static <T> Predicate<T> and(Predicate<? super T>... components) {
return new AndPredicate<T>(defensiveCopy(components));
}
/**
* Returns a predicate that evaluates to {@code true} if both of its
* components evaluate to {@code true}. The components are evaluated in
* order, and evaluation will be "short-circuited" as soon as a false
* predicate is found.
*/
public static <T> Predicate<T> and(Predicate<? super T> first,
Predicate<? super T> second) {
return new AndPredicate<T>(Predicates.<T>asList(
checkNotNull(first), checkNotNull(second)));
}
/**
* Returns a predicate that evaluates to {@code true} if any one of its
* components evaluates to {@code true}. The components are evaluated in
* order, and evaluation will be "short-circuited" as soon as a
* true predicate is found. It defensively copies the iterable passed in, so
* future changes to it won't alter the behavior of this predicate. If {@code
* components} is empty, the returned predicate will always evaluate to {@code
* false}.
*/
public static <T> Predicate<T> or(
Iterable<? extends Predicate<? super T>> components) {
return new OrPredicate<T>(defensiveCopy(components));
}
/**
* Returns a predicate that evaluates to {@code true} if any one of its
* components evaluates to {@code true}. The components are evaluated in
* order, and evaluation will be "short-circuited" as soon as a
* true predicate is found. It defensively copies the array passed in, so
* future changes to it won't alter the behavior of this predicate. If {@code
* components} is empty, the returned predicate will always evaluate to {@code
* false}.
*/
public static <T> Predicate<T> or(Predicate<? super T>... components) {
return new OrPredicate<T>(defensiveCopy(components));
}
/**
* Returns a predicate that evaluates to {@code true} if either of its
* components evaluates to {@code true}. The components are evaluated in
* order, and evaluation will be "short-circuited" as soon as a
* true predicate is found.
*/
public static <T> Predicate<T> or(
Predicate<? super T> first, Predicate<? super T> second) {
return new OrPredicate<T>(Predicates.<T>asList(
checkNotNull(first), checkNotNull(second)));
}
/**
* Returns a predicate that evaluates to {@code true} if the object being
* tested {@code equals()} the given target or both are null.
*/
public static <T> Predicate<T> equalTo(@Nullable T target) {
return (target == null)
? Predicates.<T>isNull()
: new IsEqualToPredicate<T>(target);
}
/**
* Returns a predicate that evaluates to {@code true} if the object being
* tested is an instance of the given class. If the object being tested
* is {@code null} this predicate evaluates to {@code false}.
*
* <p>If you want to filter an {@code Iterable} to narrow its type, consider
* using {@link com.google.common.collect.Iterables#filter(Iterable, Class)}
* in preference.
*
* <p><b>Warning:</b> contrary to the typical assumptions about predicates (as
* documented at {@link Predicate#apply}), the returned predicate may not be
* <i>consistent with equals</i>. For example, {@code
* instanceOf(ArrayList.class)} will yield different results for the two equal
* instances {@code Lists.newArrayList(1)} and {@code Arrays.asList(1)}.
*/
@GwtIncompatible("Class.isInstance")
public static Predicate<Object> instanceOf(Class<?> clazz) {
return new InstanceOfPredicate(clazz);
}
/**
* Returns a predicate that evaluates to {@code true} if the class being
* tested is assignable from the given class. The returned predicate
* does not allow null inputs.
*
* @since 10.0
*/
@GwtIncompatible("Class.isAssignableFrom")
@Beta
public static Predicate<Class<?>> assignableFrom(Class<?> clazz) {
return new AssignableFromPredicate(clazz);
}
/**
* Returns a predicate that evaluates to {@code true} if the object reference
* being tested is a member of the given collection. It does not defensively
* copy the collection passed in, so future changes to it will alter the
* behavior of the predicate.
*
* <p>This method can technically accept any {@code Collection<?>}, but using
* a typed collection helps prevent bugs. This approach doesn't block any
* potential users since it is always possible to use {@code
* Predicates.<Object>in()}.
*
* @param target the collection that may contain the function input
*/
public static <T> Predicate<T> in(Collection<? extends T> target) {
return new InPredicate<T>(target);
}
/**
* Returns the composition of a function and a predicate. For every {@code x},
* the generated predicate returns {@code predicate(function(x))}.
*
* @return the composition of the provided function and predicate
*/
public static <A, B> Predicate<A> compose(
Predicate<B> predicate, Function<A, ? extends B> function) {
return new CompositionPredicate<A, B>(predicate, function);
}
/**
* Returns a predicate that evaluates to {@code true} if the
* {@code CharSequence} being tested contains any match for the given
* regular expression pattern. The test used is equivalent to
* {@code Pattern.compile(pattern).matcher(arg).find()}
*
* @throws java.util.regex.PatternSyntaxException if the pattern is invalid
* @since 3.0
*/
@GwtIncompatible(value = "java.util.regex.Pattern")
public static Predicate<CharSequence> containsPattern(String pattern) {
return new ContainsPatternPredicate(pattern);
}
/**
* Returns a predicate that evaluates to {@code true} if the
* {@code CharSequence} being tested contains any match for the given
* regular expression pattern. The test used is equivalent to
* {@code pattern.matcher(arg).find()}
*
* @since 3.0
*/
@GwtIncompatible(value = "java.util.regex.Pattern")
public static Predicate<CharSequence> contains(Pattern pattern) {
return new ContainsPatternPredicate(pattern);
}
// End public API, begin private implementation classes.
// Package private for GWT serialization.
enum ObjectPredicate implements Predicate<Object> {
ALWAYS_TRUE {
@Override public boolean apply(@Nullable Object o) {
return true;
}
},
ALWAYS_FALSE {
@Override public boolean apply(@Nullable Object o) {
return false;
}
},
IS_NULL {
@Override public boolean apply(@Nullable Object o) {
return o == null;
}
},
NOT_NULL {
@Override public boolean apply(@Nullable Object o) {
return o != null;
}
};
@SuppressWarnings("unchecked") // these Object predicates work for any T
<T> Predicate<T> withNarrowedType() {
return (Predicate<T>) this;
}
}
/** @see Predicates#not(Predicate) */
private static class NotPredicate<T> implements Predicate<T>, Serializable {
final Predicate<T> predicate;
NotPredicate(Predicate<T> predicate) {
this.predicate = checkNotNull(predicate);
}
@Override
public boolean apply(T t) {
return !predicate.apply(t);
}
@Override public int hashCode() {
return ~predicate.hashCode();
}
@Override public boolean equals(@Nullable Object obj) {
if (obj instanceof NotPredicate) {
NotPredicate<?> that = (NotPredicate<?>) obj;
return predicate.equals(that.predicate);
}
return false;
}
@Override public String toString() {
return "Not(" + predicate.toString() + ")";
}
private static final long serialVersionUID = 0;
}
private static final Joiner COMMA_JOINER = Joiner.on(",");
/** @see Predicates#and(Iterable) */
private static class AndPredicate<T> implements Predicate<T>, Serializable {
private final List<? extends Predicate<? super T>> components;
private AndPredicate(List<? extends Predicate<? super T>> components) {
this.components = components;
}
@Override
public boolean apply(T t) {
for (int i = 0; i < components.size(); i++) {
if (!components.get(i).apply(t)) {
return false;
}
}
return true;
}
@Override public int hashCode() {
// 0x12472c2c is a random number to help avoid collisions with OrPredicate
return components.hashCode() + 0x12472c2c;
}
@Override public boolean equals(@Nullable Object obj) {
if (obj instanceof AndPredicate) {
AndPredicate<?> that = (AndPredicate<?>) obj;
return components.equals(that.components);
}
return false;
}
@Override public String toString() {
return "And(" + COMMA_JOINER.join(components) + ")";
}
private static final long serialVersionUID = 0;
}
/** @see Predicates#or(Iterable) */
private static class OrPredicate<T> implements Predicate<T>, Serializable {
private final List<? extends Predicate<? super T>> components;
private OrPredicate(List<? extends Predicate<? super T>> components) {
this.components = components;
}
@Override
public boolean apply(T t) {
for (int i = 0; i < components.size(); i++) {
if (components.get(i).apply(t)) {
return true;
}
}
return false;
}
@Override public int hashCode() {
// 0x053c91cf is a random number to help avoid collisions with AndPredicate
return components.hashCode() + 0x053c91cf;
}
@Override public boolean equals(@Nullable Object obj) {
if (obj instanceof OrPredicate) {
OrPredicate<?> that = (OrPredicate<?>) obj;
return components.equals(that.components);
}
return false;
}
@Override public String toString() {
return "Or(" + COMMA_JOINER.join(components) + ")";
}
private static final long serialVersionUID = 0;
}
/** @see Predicates#equalTo(Object) */
private static class IsEqualToPredicate<T>
implements Predicate<T>, Serializable {
private final T target;
private IsEqualToPredicate(T target) {
this.target = target;
}
@Override
public boolean apply(T t) {
return target.equals(t);
}
@Override public int hashCode() {
return target.hashCode();
}
@Override public boolean equals(@Nullable Object obj) {
if (obj instanceof IsEqualToPredicate) {
IsEqualToPredicate<?> that = (IsEqualToPredicate<?>) obj;
return target.equals(that.target);
}
return false;
}
@Override public String toString() {
return "IsEqualTo(" + target + ")";
}
private static final long serialVersionUID = 0;
}
/** @see Predicates#instanceOf(Class) */
@GwtIncompatible("Class.isInstance")
private static class InstanceOfPredicate
implements Predicate<Object>, Serializable {
private final Class<?> clazz;
private InstanceOfPredicate(Class<?> clazz) {
this.clazz = checkNotNull(clazz);
}
@Override
public boolean apply(@Nullable Object o) {
return clazz.isInstance(o);
}
@Override public int hashCode() {
return clazz.hashCode();
}
@Override public boolean equals(@Nullable Object obj) {
if (obj instanceof InstanceOfPredicate) {
InstanceOfPredicate that = (InstanceOfPredicate) obj;
return clazz == that.clazz;
}
return false;
}
@Override public String toString() {
return "IsInstanceOf(" + clazz.getName() + ")";
}
private static final long serialVersionUID = 0;
}
/** @see Predicates#assignableFrom(Class) */
@GwtIncompatible("Class.isAssignableFrom")
private static class AssignableFromPredicate
implements Predicate<Class<?>>, Serializable {
private final Class<?> clazz;
private AssignableFromPredicate(Class<?> clazz) {
this.clazz = checkNotNull(clazz);
}
@Override
public boolean apply(Class<?> input) {
return clazz.isAssignableFrom(input);
}
@Override public int hashCode() {
return clazz.hashCode();
}
@Override public boolean equals(@Nullable Object obj) {
if (obj instanceof AssignableFromPredicate) {
AssignableFromPredicate that = (AssignableFromPredicate) obj;
return clazz == that.clazz;
}
return false;
}
@Override public String toString() {
return "IsAssignableFrom(" + clazz.getName() + ")";
}
private static final long serialVersionUID = 0;
}
/** @see Predicates#in(Collection) */
private static class InPredicate<T> implements Predicate<T>, Serializable {
private final Collection<?> target;
private InPredicate(Collection<?> target) {
this.target = checkNotNull(target);
}
@Override
public boolean apply(T t) {
try {
return target.contains(t);
} catch (NullPointerException e) {
return false;
} catch (ClassCastException e) {
return false;
}
}
@Override public boolean equals(@Nullable Object obj) {
if (obj instanceof InPredicate) {
InPredicate<?> that = (InPredicate<?>) obj;
return target.equals(that.target);
}
return false;
}
@Override public int hashCode() {
return target.hashCode();
}
@Override public String toString() {
return "In(" + target + ")";
}
private static final long serialVersionUID = 0;
}
/** @see Predicates#compose(Predicate, Function) */
private static class CompositionPredicate<A, B>
implements Predicate<A>, Serializable {
final Predicate<B> p;
final Function<A, ? extends B> f;
private CompositionPredicate(Predicate<B> p, Function<A, ? extends B> f) {
this.p = checkNotNull(p);
this.f = checkNotNull(f);
}
@Override
public boolean apply(A a) {
return p.apply(f.apply(a));
}
@Override public boolean equals(@Nullable Object obj) {
if (obj instanceof CompositionPredicate) {
CompositionPredicate<?, ?> that = (CompositionPredicate<?, ?>) obj;
return f.equals(that.f) && p.equals(that.p);
}
return false;
}
@Override public int hashCode() {
return f.hashCode() ^ p.hashCode();
}
@Override public String toString() {
return p.toString() + "(" + f.toString() + ")";
}
private static final long serialVersionUID = 0;
}
/**
* @see Predicates#contains(Pattern)
* @see Predicates#containsPattern(String)
*/
@GwtIncompatible("Only used by other GWT-incompatible code.")
private static class ContainsPatternPredicate
implements Predicate<CharSequence>, Serializable {
final Pattern pattern;
ContainsPatternPredicate(Pattern pattern) {
this.pattern = checkNotNull(pattern);
}
ContainsPatternPredicate(String patternStr) {
this(Pattern.compile(patternStr));
}
@Override
public boolean apply(CharSequence t) {
return pattern.matcher(t).find();
}
@Override public int hashCode() {
// Pattern uses Object.hashCode, so we have to reach
// inside to build a hashCode consistent with equals.
return Objects.hashCode(pattern.pattern(), pattern.flags());
}
@Override public boolean equals(@Nullable Object obj) {
if (obj instanceof ContainsPatternPredicate) {
ContainsPatternPredicate that = (ContainsPatternPredicate) obj;
// Pattern uses Object (identity) equality, so we have to reach
// inside to compare individual fields.
return Objects.equal(pattern.pattern(), that.pattern.pattern())
&& Objects.equal(pattern.flags(), that.pattern.flags());
}
return false;
}
@Override public String toString() {
return Objects.toStringHelper(this)
.add("pattern", pattern)
.add("pattern.flags", Integer.toHexString(pattern.flags()))
.toString();
}
private static final long serialVersionUID = 0;
}
@SuppressWarnings("unchecked")
private static <T> List<Predicate<? super T>> asList(
Predicate<? super T> first, Predicate<? super T> second) {
return Arrays.<Predicate<? super T>>asList(first, second);
}
private static <T> List<T> defensiveCopy(T... array) {
return defensiveCopy(Arrays.asList(array));
}
static <T> List<T> defensiveCopy(Iterable<T> iterable) {
ArrayList<T> list = new ArrayList<T>();
for (T element : iterable) {
list.add(checkNotNull(element));
}
return list;
}
}
| Java |
/*
* Copyright (C) 2007 The Guava Authors
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package com.google.common.base;
/**
* Implemented by references that have code to run after garbage collection of their referents.
*
* @see FinalizableReferenceQueue
* @author Bob Lee
* @since 2.0 (imported from Google Collections Library)
*/
public interface FinalizableReference {
/**
* Invoked on a background thread after the referent has been garbage collected unless security
* restrictions prevented starting a background thread, in which case this method is invoked when
* new references are created.
*/
void finalizeReferent();
}
| Java |
/*
* Copyright (C) 2011 The Guava Authors
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package com.google.common.base;
import static com.google.common.base.Preconditions.checkNotNull;
import com.google.common.annotations.Beta;
import com.google.common.annotations.GwtCompatible;
import java.io.Serializable;
import java.util.Iterator;
import java.util.Set;
import javax.annotation.Nullable;
/**
* An immutable object that may contain a non-null reference to another object. Each
* instance of this type either contains a non-null reference, or contains nothing (in
* which case we say that the reference is "absent"); it is never said to "contain {@code
* null}".
*
* <p>A non-null {@code Optional<T>} reference can be used as a replacement for a nullable
* {@code T} reference. It allows you to represent "a {@code T} that must be present" and
* a "a {@code T} that might be absent" as two distinct types in your program, which can
* aid clarity.
*
* <p>Some uses of this class include
*
* <ul>
* <li>As a method return type, as an alternative to returning {@code null} to indicate
* that no value was available
* <li>To distinguish between "unknown" (for example, not present in a map) and "known to
* have no value" (present in the map, with value {@code Optional.absent()})
* <li>To wrap nullable references for storage in a collection that does not support
* {@code null} (though there are
* <a href="http://code.google.com/p/guava-libraries/wiki/LivingWithNullHostileCollections">
* several other approaches to this</a> that should be considered first)
* </ul>
*
* <p>A common alternative to using this class is to find or create a suitable
* <a href="http://en.wikipedia.org/wiki/Null_Object_pattern">null object</a> for the
* type in question.
*
* <p>This class is not intended as a direct analogue of any existing "option" or "maybe"
* construct from other programming environments, though it may bear some similarities.
*
* <p>See the Guava User Guide article on <a
* href="http://code.google.com/p/guava-libraries/wiki/UsingAndAvoidingNullExplained#Optional">
* using {@code Optional}</a>.
*
* @param <T> the type of instance that can be contained. {@code Optional} is naturally
* covariant on this type, so it is safe to cast an {@code Optional<T>} to {@code
* Optional<S>} for any supertype {@code S} of {@code T}.
* @author Kurt Alfred Kluever
* @author Kevin Bourrillion
* @since 10.0
*/
@Beta
@GwtCompatible(serializable = true)
public abstract class Optional<T> implements Serializable {
/**
* Returns an {@code Optional} instance with no contained reference.
*/
@SuppressWarnings("unchecked")
public static <T> Optional<T> absent() {
return (Optional<T>) Absent.INSTANCE;
}
/**
* Returns an {@code Optional} instance containing the given non-null reference.
*/
public static <T> Optional<T> of(T reference) {
return new Present<T>(checkNotNull(reference));
}
/**
* If {@code nullableReference} is non-null, returns an {@code Optional} instance containing that
* reference; otherwise returns {@link Optional#absent}.
*/
public static <T> Optional<T> fromNullable(@Nullable T nullableReference) {
return (nullableReference == null)
? Optional.<T>absent()
: new Present<T>(nullableReference);
}
Optional() {}
/**
* Returns {@code true} if this holder contains a (non-null) instance.
*/
public abstract boolean isPresent();
/**
* Returns the contained instance, which must be present. If the instance might be
* absent, use {@link #or(Object)} or {@link #orNull} instead.
*
* @throws IllegalStateException if the instance is absent ({@link #isPresent} returns
* {@code false})
*/
public abstract T get();
/**
* Returns the contained instance if it is present; {@code defaultValue} otherwise. If
* no default value should be required because the instance is known to be present, use
* {@link #get()} instead. For a default value of {@code null}, use {@link #orNull}.
*/
public abstract T or(T defaultValue);
/**
* Returns this {@code Optional} if it has a value present; {@code secondChoice}
* otherwise.
*/
public abstract Optional<T> or(Optional<? extends T> secondChoice);
/**
* Returns the contained instance if it is present; {@code supplier.get()} otherwise. If the
* supplier returns {@code null}, a {@link NullPointerException} will be thrown.
*
* @throws NullPointerException if the supplier returns {@code null}
*/
public abstract T or(Supplier<? extends T> supplier);
/**
* Returns the contained instance if it is present; {@code null} otherwise. If the
* instance is known to be present, use {@link #get()} instead.
*/
@Nullable public abstract T orNull();
/**
* Returns an immutable singleton {@link Set} whose only element is the
* contained instance if it is present; an empty immutable {@link Set}
* otherwise.
*
* @since 11.0
*/
public abstract Set<T> asSet();
/**
* Returns {@code true} if {@code object} is an {@code Optional} instance, and either
* the contained references are {@linkplain Object#equals equal} to each other or both
* are absent. Note that {@code Optional} instances of differing parameterized types can
* be equal.
*/
@Override public abstract boolean equals(@Nullable Object object);
/**
* Returns a hash code for this instance.
*/
@Override public abstract int hashCode();
/**
* Returns a string representation for this instance. The form of this string
* representation is unspecified.
*/
@Override public abstract String toString();
/**
* Returns the value of each present instance from the supplied {@code optionals}, in order,
* skipping over occurrences of {@link Optional#absent}. Iterators are unmodifiable and are
* evaluated lazily.
*
* @since 11.0
*/
public static <T> Iterable<T> presentInstances(final Iterable<Optional<T>> optionals) {
checkNotNull(optionals);
return new Iterable<T>() {
@Override public Iterator<T> iterator() {
return new AbstractIterator<T>() {
private final Iterator<Optional<T>> iterator = checkNotNull(optionals.iterator());
@Override protected T computeNext() {
while (iterator.hasNext()) {
Optional<T> optional = iterator.next();
if (optional.isPresent()) {
return optional.get();
}
}
return endOfData();
}
};
};
};
}
private static final long serialVersionUID = 0;
}
| Java |
/*
* Copyright (C) 2010 The Guava Authors
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package com.google.common.base;
import com.google.common.annotations.Beta;
import com.google.common.annotations.GwtCompatible;
/**
* Static methods pertaining to ASCII characters (those in the range of values
* {@code 0x00} through {@code 0x7F}), and to strings containing such
* characters.
*
* <p>ASCII utilities also exist in other classes of this package:
* <ul>
* <!-- TODO(kevinb): how can we make this not produce a warning when building gwt javadoc? -->
* <li>{@link Charsets#US_ASCII} specifies the {@code Charset} of ASCII characters.
* <li>{@link CharMatcher#ASCII} matches ASCII characters and provides text processing methods
* which operate only on the ASCII characters of a string.
* </ul>
*
* @author Craig Berry
* @author Gregory Kick
* @since 7.0
*/
@GwtCompatible
public final class Ascii {
private Ascii() {}
/* The ASCII control characters, per RFC 20. */
/**
* Null ('\0'): The all-zeros character which may serve to accomplish
* time fill and media fill. Normally used as a C string terminator.
* <p>Although RFC 20 names this as "Null", note that it is distinct
* from the C/C++ "NULL" pointer.
*
* @since 8.0
*/
public static final byte NUL = 0;
/**
* Start of Heading: A communication control character used at
* the beginning of a sequence of characters which constitute a
* machine-sensible address or routing information. Such a sequence is
* referred to as the "heading." An STX character has the effect of
* terminating a heading.
*
* @since 8.0
*/
public static final byte SOH = 1;
/**
* Start of Text: A communication control character which
* precedes a sequence of characters that is to be treated as an entity
* and entirely transmitted through to the ultimate destination. Such a
* sequence is referred to as "text." STX may be used to terminate a
* sequence of characters started by SOH.
*
* @since 8.0
*/
public static final byte STX = 2;
/**
* End of Text: A communication control character used to
* terminate a sequence of characters started with STX and transmitted
* as an entity.
*
* @since 8.0
*/
public static final byte ETX = 3;
/**
* End of Transmission: A communication control character used
* to indicate the conclusion of a transmission, which may have
* contained one or more texts and any associated headings.
*
* @since 8.0
*/
public static final byte EOT = 4;
/**
* Enquiry: A communication control character used in data
* communication systems as a request for a response from a remote
* station. It may be used as a "Who Are You" (WRU) to obtain
* identification, or may be used to obtain station status, or both.
*
* @since 8.0
*/
public static final byte ENQ = 5;
/**
* Acknowledge: A communication control character transmitted
* by a receiver as an affirmative response to a sender.
*
* @since 8.0
*/
public static final byte ACK = 6;
/**
* Bell ('\a'): A character for use when there is a need to call for
* human attention. It may control alarm or attention devices.
*
* @since 8.0
*/
public static final byte BEL = 7;
/**
* Backspace ('\b'): A format effector which controls the movement of
* the printing position one printing space backward on the same
* printing line. (Applicable also to display devices.)
*
* @since 8.0
*/
public static final byte BS = 8;
/**
* Horizontal Tabulation ('\t'): A format effector which controls the
* movement of the printing position to the next in a series of
* predetermined positions along the printing line. (Applicable also to
* display devices and the skip function on punched cards.)
*
* @since 8.0
*/
public static final byte HT = 9;
/**
* Line Feed ('\n'): A format effector which controls the movement of
* the printing position to the next printing line. (Applicable also to
* display devices.) Where appropriate, this character may have the
* meaning "New Line" (NL), a format effector which controls the
* movement of the printing point to the first printing position on the
* next printing line. Use of this convention requires agreement
* between sender and recipient of data.
*
* @since 8.0
*/
public static final byte LF = 10;
/**
* Alternate name for {@link #LF}. ({@code LF} is preferred.)
*
* @since 8.0
*/
public static final byte NL = 10;
/**
* Vertical Tabulation ('\v'): A format effector which controls the
* movement of the printing position to the next in a series of
* predetermined printing lines. (Applicable also to display devices.)
*
* @since 8.0
*/
public static final byte VT = 11;
/**
* Form Feed ('\f'): A format effector which controls the movement of
* the printing position to the first pre-determined printing line on
* the next form or page. (Applicable also to display devices.)
*
* @since 8.0
*/
public static final byte FF = 12;
/**
* Carriage Return ('\r'): A format effector which controls the
* movement of the printing position to the first printing position on
* the same printing line. (Applicable also to display devices.)
*
* @since 8.0
*/
public static final byte CR = 13;
/**
* Shift Out: A control character indicating that the code
* combinations which follow shall be interpreted as outside of the
* character set of the standard code table until a Shift In character
* is reached.
*
* @since 8.0
*/
public static final byte SO = 14;
/**
* Shift In: A control character indicating that the code
* combinations which follow shall be interpreted according to the
* standard code table.
*
* @since 8.0
*/
public static final byte SI = 15;
/**
* Data Link Escape: A communication control character which
* will change the meaning of a limited number of contiguously following
* characters. It is used exclusively to provide supplementary controls
* in data communication networks.
*
* @since 8.0
*/
public static final byte DLE = 16;
/**
* Device Controls: Characters for the control
* of ancillary devices associated with data processing or
* telecommunication systems, more especially switching devices "on" or
* "off." (If a single "stop" control is required to interrupt or turn
* off ancillary devices, DC4 is the preferred assignment.)
*
* @since 8.0
*/
public static final byte DC1 = 17; // aka XON
/**
* Transmission on/off: Although originally defined as DC1, this ASCII
* control character is now better known as the XON code used for software
* flow control in serial communications. The main use is restarting
* the transmission after the communication has been stopped by the XOFF
* control code.
*
* @since 8.0
*/
public static final byte XON = 17; // aka DC1
/**
* @see #DC1
*
* @since 8.0
*/
public static final byte DC2 = 18;
/**
* @see #DC1
*
* @since 8.0
*/
public static final byte DC3 = 19; // aka XOFF
/**
* Transmission off. @see #XON
*
* @since 8.0
*/
public static final byte XOFF = 19; // aka DC3
/**
* @see #DC1
*
* @since 8.0
*/
public static final byte DC4 = 20;
/**
* Negative Acknowledge: A communication control character
* transmitted by a receiver as a negative response to the sender.
*
* @since 8.0
*/
public static final byte NAK = 21;
/**
* Synchronous Idle: A communication control character used by
* a synchronous transmission system in the absence of any other
* character to provide a signal from which synchronism may be achieved
* or retained.
*
* @since 8.0
*/
public static final byte SYN = 22;
/**
* End of Transmission Block: A communication control character
* used to indicate the end of a block of data for communication
* purposes. ETB is used for blocking data where the block structure is
* not necessarily related to the processing format.
*
* @since 8.0
*/
public static final byte ETB = 23;
/**
* Cancel: A control character used to indicate that the data
* with which it is sent is in error or is to be disregarded.
*
* @since 8.0
*/
public static final byte CAN = 24;
/**
* End of Medium: A control character associated with the sent
* data which may be used to identify the physical end of the medium, or
* the end of the used, or wanted, portion of information recorded on a
* medium. (The position of this character does not necessarily
* correspond to the physical end of the medium.)
*
* @since 8.0
*/
public static final byte EM = 25;
/**
* Substitute: A character that may be substituted for a
* character which is determined to be invalid or in error.
*
* @since 8.0
*/
public static final byte SUB = 26;
/**
* Escape: A control character intended to provide code
* extension (supplementary characters) in general information
* interchange. The Escape character itself is a prefix affecting the
* interpretation of a limited number of contiguously following
* characters.
*
* @since 8.0
*/
public static final byte ESC = 27;
/**
* File/Group/Record/Unit Separator: These information separators may be
* used within data in optional fashion, except that their hierarchical
* relationship shall be: FS is the most inclusive, then GS, then RS,
* and US is least inclusive. (The content and length of a File, Group,
* Record, or Unit are not specified.)
*
* @since 8.0
*/
public static final byte FS = 28;
/**
* @see #FS
*
* @since 8.0
*/
public static final byte GS = 29;
/**
* @see #FS
*
* @since 8.0
*/
public static final byte RS = 30;
/**
* @see #FS
*
* @since 8.0
*/
public static final byte US = 31;
/**
* Space: A normally non-printing graphic character used to
* separate words. It is also a format effector which controls the
* movement of the printing position, one printing position forward.
* (Applicable also to display devices.)
*
* @since 8.0
*/
public static final byte SP = 32;
/**
* Alternate name for {@link #SP}.
*
* @since 8.0
*/
public static final byte SPACE = 32;
/**
* Delete: This character is used primarily to "erase" or
* "obliterate" erroneous or unwanted characters in perforated tape.
*
* @since 8.0
*/
public static final byte DEL = 127;
/**
* The minimum value of an ASCII character.
*
* @since 9.0
*/
@Beta
public static final int MIN = 0;
/**
* The maximum value of an ASCII character.
*
* @since 9.0
*/
@Beta
public static final int MAX = 127;
/**
* Returns a copy of the input string in which all {@linkplain #isUpperCase(char) uppercase ASCII
* characters} have been converted to lowercase. All other characters are copied without
* modification.
*/
public static String toLowerCase(String string) {
int length = string.length();
StringBuilder builder = new StringBuilder(length);
for (int i = 0; i < length; i++) {
builder.append(toLowerCase(string.charAt(i)));
}
return builder.toString();
}
/**
* If the argument is an {@linkplain #isUpperCase(char) uppercase ASCII character} returns the
* lowercase equivalent. Otherwise returns the argument.
*/
public static char toLowerCase(char c) {
return isUpperCase(c) ? (char) (c ^ 0x20) : c;
}
/**
* Returns a copy of the input string in which all {@linkplain #isLowerCase(char) lowercase ASCII
* characters} have been converted to uppercase. All other characters are copied without
* modification.
*/
public static String toUpperCase(String string) {
int length = string.length();
StringBuilder builder = new StringBuilder(length);
for (int i = 0; i < length; i++) {
builder.append(toUpperCase(string.charAt(i)));
}
return builder.toString();
}
/**
* If the argument is a {@linkplain #isLowerCase(char) lowercase ASCII character} returns the
* uppercase equivalent. Otherwise returns the argument.
*/
public static char toUpperCase(char c) {
return isLowerCase(c) ? (char) (c & 0x5f) : c;
}
/**
* Indicates whether {@code c} is one of the twenty-six lowercase ASCII alphabetic characters
* between {@code 'a'} and {@code 'z'} inclusive. All others (including non-ASCII characters)
* return {@code false}.
*/
public static boolean isLowerCase(char c) {
return (c >= 'a') && (c <= 'z');
}
/**
* Indicates whether {@code c} is one of the twenty-six uppercase ASCII alphabetic characters
* between {@code 'A'} and {@code 'Z'} inclusive. All others (including non-ASCII characters)
* return {@code false}.
*/
public static boolean isUpperCase(char c) {
return (c >= 'A') && (c <= 'Z');
}
}
| Java |
/*
* Copyright (C) 2006 The Guava Authors
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package com.google.common.base;
import com.google.common.annotations.GwtCompatible;
/**
* Utility class for converting between various ASCII case formats.
*
* @author Mike Bostock
* @since 1.0
*/
@GwtCompatible
public enum CaseFormat {
/**
* Hyphenated variable naming convention, e.g., "lower-hyphen".
*/
LOWER_HYPHEN(CharMatcher.is('-'), "-"),
/**
* C++ variable naming convention, e.g., "lower_underscore".
*/
LOWER_UNDERSCORE(CharMatcher.is('_'), "_"),
/**
* Java variable naming convention, e.g., "lowerCamel".
*/
LOWER_CAMEL(CharMatcher.inRange('A', 'Z'), ""),
/**
* Java and C++ class naming convention, e.g., "UpperCamel".
*/
UPPER_CAMEL(CharMatcher.inRange('A', 'Z'), ""),
/**
* Java and C++ constant naming convention, e.g., "UPPER_UNDERSCORE".
*/
UPPER_UNDERSCORE(CharMatcher.is('_'), "_");
private final CharMatcher wordBoundary;
private final String wordSeparator;
CaseFormat(CharMatcher wordBoundary, String wordSeparator) {
this.wordBoundary = wordBoundary;
this.wordSeparator = wordSeparator;
}
/**
* Converts the specified {@code String s} from this format to the specified {@code format}. A
* "best effort" approach is taken; if {@code s} does not conform to the assumed format, then the
* behavior of this method is undefined but we make a reasonable effort at converting anyway.
*/
public String to(CaseFormat format, String s) {
if (format == null) {
throw new NullPointerException();
}
if (s == null) {
throw new NullPointerException();
}
if (format == this) {
return s;
}
/* optimize cases where no camel conversion is required */
switch (this) {
case LOWER_HYPHEN:
switch (format) {
case LOWER_UNDERSCORE:
return s.replace('-', '_');
case UPPER_UNDERSCORE:
return Ascii.toUpperCase(s.replace('-', '_'));
}
break;
case LOWER_UNDERSCORE:
switch (format) {
case LOWER_HYPHEN:
return s.replace('_', '-');
case UPPER_UNDERSCORE:
return Ascii.toUpperCase(s);
}
break;
case UPPER_UNDERSCORE:
switch (format) {
case LOWER_HYPHEN:
return Ascii.toLowerCase(s.replace('_', '-'));
case LOWER_UNDERSCORE:
return Ascii.toLowerCase(s);
}
break;
}
// otherwise, deal with camel conversion
StringBuilder out = null;
int i = 0;
int j = -1;
while ((j = wordBoundary.indexIn(s, ++j)) != -1) {
if (i == 0) {
// include some extra space for separators
out = new StringBuilder(s.length() + 4 * wordSeparator.length());
out.append(format.normalizeFirstWord(s.substring(i, j)));
} else {
out.append(format.normalizeWord(s.substring(i, j)));
}
out.append(format.wordSeparator);
i = j + wordSeparator.length();
}
if (i == 0) {
return format.normalizeFirstWord(s);
}
out.append(format.normalizeWord(s.substring(i)));
return out.toString();
}
private String normalizeFirstWord(String word) {
switch (this) {
case LOWER_CAMEL:
return Ascii.toLowerCase(word);
default:
return normalizeWord(word);
}
}
private String normalizeWord(String word) {
switch (this) {
case LOWER_HYPHEN:
return Ascii.toLowerCase(word);
case LOWER_UNDERSCORE:
return Ascii.toLowerCase(word);
case LOWER_CAMEL:
return firstCharOnlyToUpper(word);
case UPPER_CAMEL:
return firstCharOnlyToUpper(word);
case UPPER_UNDERSCORE:
return Ascii.toUpperCase(word);
}
throw new RuntimeException("unknown case: " + this);
}
private static String firstCharOnlyToUpper(String word) {
int length = word.length();
if (length == 0) {
return word;
}
return new StringBuilder(length)
.append(Ascii.toUpperCase(word.charAt(0)))
.append(Ascii.toLowerCase(word.substring(1)))
.toString();
}
}
| Java |
/*
* Copyright (C) 2007 The Guava Authors
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package com.google.common.base;
import com.google.common.annotations.GwtCompatible;
/**
* A class that can supply objects of a single type. Semantically, this could
* be a factory, generator, builder, closure, or something else entirely. No
* guarantees are implied by this interface.
*
* @author Harry Heymann
* @since 2.0 (imported from Google Collections Library)
*/
@GwtCompatible
public interface Supplier<T> {
/**
* Retrieves an instance of the appropriate type. The returned object may or
* may not be a new instance, depending on the implementation.
*
* @return an instance of the appropriate type
*/
T get();
}
| Java |
/*
* Copyright (C) 2007 The Guava Authors
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package com.google.common.base;
import java.util.Collections;
import java.util.HashMap;
import java.util.Map;
/**
* This class provides default values for all Java types, as defined by the JLS.
*
* @author Ben Yu
*/
public final class Defaults {
private Defaults() {}
private static final Map<Class<?>, Object> DEFAULTS;
static {
Map<Class<?>, Object> map = new HashMap<Class<?>, Object>();
put(map, boolean.class, false);
put(map, char.class, '\0');
put(map, byte.class, (byte) 0);
put(map, short.class, (short) 0);
put(map, int.class, 0);
put(map, long.class, 0L);
put(map, float.class, 0f);
put(map, double.class, 0d);
DEFAULTS = Collections.unmodifiableMap(map);
}
private static <T> void put(Map<Class<?>, Object> map, Class<T> type, T value) {
map.put(type, value);
}
/**
* Returns the default value of {@code type} as defined by JLS --- {@code 0} for numbers, {@code
* false} for {@code boolean} and {@code '\0'} for {@code char}. For non-primitive types and
* {@code void}, null is returned.
*/
@SuppressWarnings("unchecked")
public static <T> T defaultValue(Class<T> type) {
return (T) DEFAULTS.get(type);
}
}
| Java |
/*
* Copyright (C) 2008 The Guava Authors
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package com.google.common.base;
import static com.google.common.base.Preconditions.checkNotNull;
import static com.google.common.base.Preconditions.checkState;
import static java.util.concurrent.TimeUnit.MICROSECONDS;
import static java.util.concurrent.TimeUnit.MILLISECONDS;
import static java.util.concurrent.TimeUnit.NANOSECONDS;
import static java.util.concurrent.TimeUnit.SECONDS;
import com.google.common.annotations.Beta;
import com.google.common.annotations.GwtCompatible;
import com.google.common.annotations.GwtIncompatible;
import java.util.concurrent.TimeUnit;
/**
* An object that measures elapsed time in nanoseconds. It is useful to measure
* elapsed time using this class instead of direct calls to {@link
* System#nanoTime} for a few reasons:
*
* <ul>
* <li>An alternate time source can be substituted, for testing or performance
* reasons.
* <li>As documented by {@code nanoTime}, the value returned has no absolute
* meaning, and can only be interpreted as relative to another timestamp
* returned by {@code nanoTime} at a different time. {@code Stopwatch} is a
* more effective abstraction because it exposes only these relative values,
* not the absolute ones.
* </ul>
*
* <p>Basic usage:
* <pre>
* Stopwatch stopwatch = new Stopwatch().{@link #start start}();
* doSomething();
* stopwatch.{@link #stop stop}(); // optional
*
* long millis = stopwatch.{@link #elapsedMillis elapsedMillis}();
*
* log.info("that took: " + stopwatch); // formatted string like "12.3 ms"
* </pre>
*
* <p>Stopwatch methods are not idempotent; it is an error to start or stop a
* stopwatch that is already in the desired state.
*
* <p>When testing code that uses this class, use the {@linkplain
* #Stopwatch(Ticker) alternate constructor} to supply a fake or mock ticker.
* <!-- TODO(kevinb): restore the "such as" --> This allows you to
* simulate any valid behavior of the stopwatch.
*
* <p><b>Note:</b> This class is not thread-safe.
*
* @author Kevin Bourrillion
* @since 10.0
*/
@Beta
@GwtCompatible(emulated=true)
public final class Stopwatch {
private final Ticker ticker;
private boolean isRunning;
private long elapsedNanos;
private long startTick;
/**
* Creates (but does not start) a new stopwatch using {@link System#nanoTime}
* as its time source.
*/
public Stopwatch() {
this(Ticker.systemTicker());
}
/**
* Creates (but does not start) a new stopwatch, using the specified time
* source.
*/
public Stopwatch(Ticker ticker) {
this.ticker = checkNotNull(ticker);
}
/**
* Returns {@code true} if {@link #start()} has been called on this stopwatch,
* and {@link #stop()} has not been called since the last call to {@code
* start()}.
*/
public boolean isRunning() {
return isRunning;
}
/**
* Starts the stopwatch.
*
* @return this {@code Stopwatch} instance
* @throws IllegalStateException if the stopwatch is already running.
*/
public Stopwatch start() {
checkState(!isRunning);
isRunning = true;
startTick = ticker.read();
return this;
}
/**
* Stops the stopwatch. Future reads will return the fixed duration that had
* elapsed up to this point.
*
* @return this {@code Stopwatch} instance
* @throws IllegalStateException if the stopwatch is already stopped.
*/
public Stopwatch stop() {
long tick = ticker.read();
checkState(isRunning);
isRunning = false;
elapsedNanos += tick - startTick;
return this;
}
/**
* Sets the elapsed time for this stopwatch to zero,
* and places it in a stopped state.
*
* @return this {@code Stopwatch} instance
*/
public Stopwatch reset() {
elapsedNanos = 0;
isRunning = false;
return this;
}
private long elapsedNanos() {
return isRunning ? ticker.read() - startTick + elapsedNanos : elapsedNanos;
}
/**
* Returns the current elapsed time shown on this stopwatch, expressed
* in the desired time unit, with any fraction rounded down.
*
* <p>Note that the overhead of measurement can be more than a microsecond, so
* it is generally not useful to specify {@link TimeUnit#NANOSECONDS}
* precision here.
*/
public long elapsedTime(TimeUnit desiredUnit) {
return desiredUnit.convert(elapsedNanos(), NANOSECONDS);
}
/**
* Returns the current elapsed time shown on this stopwatch, expressed
* in milliseconds, with any fraction rounded down. This is identical to
* {@code elapsedTime(TimeUnit.MILLISECONDS}.
*/
public long elapsedMillis() {
return elapsedTime(MILLISECONDS);
}
/**
* Returns a string representation of the current elapsed time; equivalent to
* {@code toString(4)} (four significant figures).
*/
@GwtIncompatible("String.format()")
@Override public String toString() {
return toString(4);
}
/**
* Returns a string representation of the current elapsed time, choosing an
* appropriate unit and using the specified number of significant figures.
* For example, at the instant when {@code elapsedTime(NANOSECONDS)} would
* return {1234567}, {@code toString(4)} returns {@code "1.235 ms"}.
*/
@GwtIncompatible("String.format()")
public String toString(int significantDigits) {
long nanos = elapsedNanos();
TimeUnit unit = chooseUnit(nanos);
double value = (double) nanos / NANOSECONDS.convert(1, unit);
// Too bad this functionality is not exposed as a regular method call
return String.format("%." + significantDigits + "g %s",
value, abbreviate(unit));
}
private static TimeUnit chooseUnit(long nanos) {
if (SECONDS.convert(nanos, NANOSECONDS) > 0) {
return SECONDS;
}
if (MILLISECONDS.convert(nanos, NANOSECONDS) > 0) {
return MILLISECONDS;
}
if (MICROSECONDS.convert(nanos, NANOSECONDS) > 0) {
return MICROSECONDS;
}
return NANOSECONDS;
}
private static String abbreviate(TimeUnit unit) {
switch (unit) {
case NANOSECONDS:
return "ns";
case MICROSECONDS:
return "\u03bcs"; // μs
case MILLISECONDS:
return "ms";
case SECONDS:
return "s";
default:
throw new AssertionError();
}
}
}
| Java |
/*
* Copyright (C) 2009 The Guava Authors
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package com.google.common.base;
import com.google.common.annotations.GwtCompatible;
/**
* Methods factored out so that they can be emulated differently in GWT.
*
* @author Jesse Wilson
*/
@GwtCompatible(emulated = true)
final class Platform {
private Platform() {}
/** Returns a thread-local 1024-char array. */
static char[] charBufferFromThreadLocal() {
return DEST_TL.get();
}
/** Calls {@link System#nanoTime()}. */
static long systemNanoTime() {
return System.nanoTime();
}
/**
* A thread-local destination buffer to keep us from creating new buffers.
* The starting size is 1024 characters. If we grow past this we don't
* put it back in the threadlocal, we just keep going and grow as needed.
*/
private static final ThreadLocal<char[]> DEST_TL = new ThreadLocal<char[]>() {
@Override
protected char[] initialValue() {
return new char[1024];
}
};
static CharMatcher precomputeCharMatcher(CharMatcher matcher) {
return matcher.precomputedInternal();
}
}
| Java |
/*
* Copyright (C) 2010 The Guava Authors
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package com.google.common.base;
import static com.google.common.base.Preconditions.checkArgument;
import static com.google.common.base.Preconditions.checkNotNull;
import com.google.common.annotations.Beta;
import com.google.common.annotations.GwtCompatible;
import com.google.common.annotations.VisibleForTesting;
import java.util.Formatter;
import javax.annotation.Nullable;
/**
* Static utility methods pertaining to {@code String} or {@code CharSequence}
* instances.
*
* @author Kevin Bourrillion
* @since 3.0
*/
@GwtCompatible
public final class Strings {
private Strings() {}
/**
* Returns the given string if it is non-null; the empty string otherwise.
*
* @param string the string to test and possibly return
* @return {@code string} itself if it is non-null; {@code ""} if it is null
*/
public static String nullToEmpty(@Nullable String string) {
return (string == null) ? "" : string;
}
/**
* Returns the given string if it is nonempty; {@code null} otherwise.
*
* @param string the string to test and possibly return
* @return {@code string} itself if it is nonempty; {@code null} if it is
* empty or null
*/
public static @Nullable String emptyToNull(@Nullable String string) {
return isNullOrEmpty(string) ? null : string;
}
/**
* Returns {@code true} if the given string is null or is the empty string.
*
* <p>Consider normalizing your string references with {@link #nullToEmpty}.
* If you do, you can use {@link String#isEmpty()} instead of this
* method, and you won't need special null-safe forms of methods like {@link
* String#toUpperCase} either. Or, if you'd like to normalize "in the other
* direction," converting empty strings to {@code null}, you can use {@link
* #emptyToNull}.
*
* @param string a string reference to check
* @return {@code true} if the string is null or is the empty string
*/
public static boolean isNullOrEmpty(@Nullable String string) {
return string == null || string.length() == 0; // string.isEmpty() in Java 6
}
/**
* Returns a string, of length at least {@code minLength}, consisting of
* {@code string} prepended with as many copies of {@code padChar} as are
* necessary to reach that length. For example,
*
* <ul>
* <li>{@code padStart("7", 3, '0')} returns {@code "007"}
* <li>{@code padStart("2010", 3, '0')} returns {@code "2010"}
* </ul>
*
* <p>See {@link Formatter} for a richer set of formatting capabilities.
*
* @param string the string which should appear at the end of the result
* @param minLength the minimum length the resulting string must have. Can be
* zero or negative, in which case the input string is always returned.
* @param padChar the character to insert at the beginning of the result until
* the minimum length is reached
* @return the padded string
*/
public static String padStart(String string, int minLength, char padChar) {
checkNotNull(string); // eager for GWT.
if (string.length() >= minLength) {
return string;
}
StringBuilder sb = new StringBuilder(minLength);
for (int i = string.length(); i < minLength; i++) {
sb.append(padChar);
}
sb.append(string);
return sb.toString();
}
/**
* Returns a string, of length at least {@code minLength}, consisting of
* {@code string} appended with as many copies of {@code padChar} as are
* necessary to reach that length. For example,
*
* <ul>
* <li>{@code padEnd("4.", 5, '0')} returns {@code "4.000"}
* <li>{@code padEnd("2010", 3, '!')} returns {@code "2010"}
* </ul>
*
* <p>See {@link Formatter} for a richer set of formatting capabilities.
*
* @param string the string which should appear at the beginning of the result
* @param minLength the minimum length the resulting string must have. Can be
* zero or negative, in which case the input string is always returned.
* @param padChar the character to append to the end of the result until the
* minimum length is reached
* @return the padded string
*/
public static String padEnd(String string, int minLength, char padChar) {
checkNotNull(string); // eager for GWT.
if (string.length() >= minLength) {
return string;
}
StringBuilder sb = new StringBuilder(minLength);
sb.append(string);
for (int i = string.length(); i < minLength; i++) {
sb.append(padChar);
}
return sb.toString();
}
/**
* Returns a string consisting of a specific number of concatenated copies of
* an input string. For example, {@code repeat("hey", 3)} returns the string
* {@code "heyheyhey"}.
*
* @param string any non-null string
* @param count the number of times to repeat it; a nonnegative integer
* @return a string containing {@code string} repeated {@code count} times
* (the empty string if {@code count} is zero)
* @throws IllegalArgumentException if {@code count} is negative
*/
public static String repeat(String string, int count) {
checkNotNull(string); // eager for GWT.
if (count <= 1) {
checkArgument(count >= 0, "invalid count: %s", count);
return (count == 0) ? "" : string;
}
// IF YOU MODIFY THE CODE HERE, you must update StringsRepeatBenchmark
final int len = string.length();
final long longSize = (long) len * (long) count;
final int size = (int) longSize;
if (size != longSize) {
throw new ArrayIndexOutOfBoundsException("Required array size too large: "
+ String.valueOf(longSize));
}
final char[] array = new char[size];
string.getChars(0, len, array, 0);
int n;
for (n = len; n < size - n; n <<= 1) {
System.arraycopy(array, 0, array, n, n);
}
System.arraycopy(array, 0, array, n, size - n);
return new String(array);
}
/**
* Returns the longest string {@code prefix} such that
* {@code a.toString().startsWith(prefix) && b.toString().startsWith(prefix)},
* taking care not to split surrogate pairs. If {@code a} and {@code b} have
* no common prefix, returns the empty string.
*
* @since 11.0
*/
@Beta
public static String commonPrefix(CharSequence a, CharSequence b) {
checkNotNull(a);
checkNotNull(b);
int maxPrefixLength = Math.min(a.length(), b.length());
int p = 0;
while (p < maxPrefixLength && a.charAt(p) == b.charAt(p)) {
p++;
}
if (validSurrogatePairAt(a, p - 1) || validSurrogatePairAt(b, p - 1)) {
p--;
}
return a.subSequence(0, p).toString();
}
/**
* Returns the longest string {@code suffix} such that
* {@code a.toString().endsWith(suffix) && b.toString().endsWith(suffix)},
* taking care not to split surrogate pairs. If {@code a} and {@code b} have
* no common suffix, returns the empty string.
*
* @since 11.0
*/
@Beta
public static String commonSuffix(CharSequence a, CharSequence b) {
checkNotNull(a);
checkNotNull(b);
int maxSuffixLength = Math.min(a.length(), b.length());
int s = 0;
while (s < maxSuffixLength
&& a.charAt(a.length() - s - 1) == b.charAt(b.length() - s - 1)) {
s++;
}
if (validSurrogatePairAt(a, a.length() - s - 1)
|| validSurrogatePairAt(b, b.length() - s - 1)) {
s--;
}
return a.subSequence(a.length() - s, a.length()).toString();
}
/**
* True when a valid surrogate pair starts at the given {@code index} in the
* given {@code string}. Out-of-range indexes return false.
*/
@VisibleForTesting
static boolean validSurrogatePairAt(CharSequence string, int index) {
return index >= 0 && index <= (string.length() - 2)
&& Character.isHighSurrogate(string.charAt(index))
&& Character.isLowSurrogate(string.charAt(index + 1));
}
}
| Java |
/*
* Copyright (C) 2007 The Guava Authors
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
/**
* Basic utility libraries and interfaces.
*
* <p>This package is a part of the open-source
* <a href="http://guava-libraries.googlecode.com">Guava libraries</a>.
*
* <h2>Contents</h2>
*
* <h3>String-related utilities</h3>
*
* <ul>
* <li>{@link com.google.common.base.Ascii}
* <li>{@link com.google.common.base.CaseFormat}
* <li>{@link com.google.common.base.CharMatcher}
* <li>{@link com.google.common.base.Charsets}
* <li>{@link com.google.common.base.Joiner}
* <li>{@link com.google.common.base.Splitter}
* <li>{@link com.google.common.base.Strings}
* </ul>
*
* <h3>Function types</h3>
*
* <ul>
* <li>{@link com.google.common.base.Function},
* {@link com.google.common.base.Functions}
* <li>{@link com.google.common.base.Predicate},
* {@link com.google.common.base.Predicates}
* <li>{@link com.google.common.base.Equivalence},
* {@link com.google.common.base.Equivalences}
* <li>{@link com.google.common.base.Supplier},
* {@link com.google.common.base.Suppliers}
* </ul>
*
* <h3>Other</h3>
*
* <ul>
* <li>{@link com.google.common.base.Defaults}
* <li>{@link com.google.common.base.Enums}
* <li>{@link com.google.common.base.Objects}
* <li>{@link com.google.common.base.Optional}
* <li>{@link com.google.common.base.Preconditions}
* <li>{@link com.google.common.base.Stopwatch}
* <li>{@link com.google.common.base.Throwables}
* </ul>
*
*/
@ParametersAreNonnullByDefault
package com.google.common.base;
import javax.annotation.ParametersAreNonnullByDefault;
| Java |
/*
* Copyright (C) 2011 The Guava Authors
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package com.google.common.base;
import static com.google.common.base.Preconditions.checkNotNull;
import com.google.common.annotations.Beta;
import com.google.common.annotations.GwtCompatible;
import java.io.Serializable;
import javax.annotation.Nullable;
/**
* Utility methods for working with {@link Enum} instances.
*
* @author Steve McKay
*
* @since 9.0
*/
@GwtCompatible
@Beta
public final class Enums {
private Enums() {}
/**
* Returns a {@link Function} that maps an {@link Enum} name to the associated
* {@code Enum} constant. The {@code Function} will return {@code null} if the
* {@code Enum} constant does not exist.
*
* @param enumClass the {@link Class} of the {@code Enum} declaring the
* constant values.
*/
public static <T extends Enum<T>> Function<String, T> valueOfFunction(Class<T> enumClass) {
return new ValueOfFunction<T>(enumClass);
}
/**
* A {@link Function} that maps an {@link Enum} name to the associated
* constant, or {@code null} if the constant does not exist.
*/
private static final class ValueOfFunction<T extends Enum<T>>
implements Function<String, T>, Serializable {
private final Class<T> enumClass;
private ValueOfFunction(Class<T> enumClass) {
this.enumClass = checkNotNull(enumClass);
}
@Override
public T apply(String value) {
try {
return Enum.valueOf(enumClass, value);
} catch (IllegalArgumentException e) {
return null;
}
}
@Override public boolean equals(@Nullable Object obj) {
return obj instanceof ValueOfFunction &&
enumClass.equals(((ValueOfFunction) obj).enumClass);
}
@Override public int hashCode() {
return enumClass.hashCode();
}
@Override public String toString() {
return "Enums.valueOf(" + enumClass + ")";
}
private static final long serialVersionUID = 0;
}
/**
* Returns an optional enum constant for the given type, using {@link Enum#valueOf}. If the
* constant does not exist, {@link Optional#absent} is returned. A common use case is for parsing
* user input or falling back to a default enum constant. For example,
* {@code Enums.getIfPresent(Country.class, countryInput).or(Country.DEFAULT);}
*
* @since 12.0
*/
public static <T extends Enum<T>> Optional<T> getIfPresent(Class<T> enumClass, String value) {
checkNotNull(enumClass);
checkNotNull(value);
try {
return Optional.of(Enum.valueOf(enumClass, value));
} catch (IllegalArgumentException iae) {
return Optional.absent();
}
}
}
| Java |
/*
* Copyright (C) 2007 The Guava Authors
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package com.google.common.base;
import java.lang.ref.ReferenceQueue;
import java.lang.ref.SoftReference;
/**
* Soft reference with a {@code finalizeReferent()} method which a background thread invokes after
* the garbage collector reclaims the referent. This is a simpler alternative to using a {@link
* ReferenceQueue}.
*
* @author Bob Lee
* @since 2.0 (imported from Google Collections Library)
*/
public abstract class FinalizableSoftReference<T> extends SoftReference<T>
implements FinalizableReference {
/**
* Constructs a new finalizable soft reference.
*
* @param referent to softly reference
* @param queue that should finalize the referent
*/
protected FinalizableSoftReference(T referent, FinalizableReferenceQueue queue) {
super(referent, queue.queue);
queue.cleanUp();
}
}
| Java |
/*
* Copyright (C) 2007 The Guava Authors
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package com.google.common.base;
import java.lang.ref.ReferenceQueue;
import java.lang.ref.WeakReference;
/**
* Weak reference with a {@code finalizeReferent()} method which a background thread invokes after
* the garbage collector reclaims the referent. This is a simpler alternative to using a {@link
* ReferenceQueue}.
*
* @author Bob Lee
* @since 2.0 (imported from Google Collections Library)
*/
public abstract class FinalizableWeakReference<T> extends WeakReference<T>
implements FinalizableReference {
/**
* Constructs a new finalizable weak reference.
*
* @param referent to weakly reference
* @param queue that should finalize the referent
*/
protected FinalizableWeakReference(T referent, FinalizableReferenceQueue queue) {
super(referent, queue.queue);
queue.cleanUp();
}
}
| Java |
/*
* Copyright (C) 2010 The Guava Authors
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package com.google.common.base;
import static com.google.common.base.Preconditions.checkNotNull;
import com.google.common.annotations.Beta;
import com.google.common.annotations.GwtCompatible;
import java.io.Serializable;
import javax.annotation.Nullable;
/**
* A strategy for determining whether two instances are considered equivalent. Examples of
* equivalences are the {@link Equivalences#identity() identity equivalence} and {@link
* Equivalences#equals equals equivalence}.
*
* @author Bob Lee
* @author Ben Yu
* @author Gregory Kick
* @since 10.0 (<a href="http://code.google.com/p/guava-libraries/wiki/Compatibility"
* >mostly source-compatible</a> since 4.0)
*/
@Beta
@GwtCompatible
public abstract class Equivalence<T> {
/**
* Constructor for use by subclasses.
*/
protected Equivalence() {}
/**
* Returns {@code true} if the given objects are considered equivalent.
*
* <p>The {@code equivalent} method implements an equivalence relation on object references:
*
* <ul>
* <li>It is <i>reflexive</i>: for any reference {@code x}, including null, {@code
* equivalent(x, x)} returns {@code true}.
* <li>It is <i>symmetric</i>: for any references {@code x} and {@code y}, {@code
* equivalent(x, y) == equivalent(y, x)}.
* <li>It is <i>transitive</i>: for any references {@code x}, {@code y}, and {@code z}, if
* {@code equivalent(x, y)} returns {@code true} and {@code equivalent(y, z)} returns {@code
* true}, then {@code equivalent(x, z)} returns {@code true}.
* <li>It is <i>consistent</i>: for any references {@code x} and {@code y}, multiple invocations
* of {@code equivalent(x, y)} consistently return {@code true} or consistently return {@code
* false} (provided that neither {@code x} nor {@code y} is modified).
* </ul>
*/
public final boolean equivalent(@Nullable T a, @Nullable T b) {
if (a == b) {
return true;
}
if (a == null || b == null) {
return false;
}
return doEquivalent(a, b);
}
/**
* Returns {@code true} if {@code a} and {@code b} are considered equivalent.
*
* <p>Called by {@link #equivalent}. {@code a} and {@code b} are not the same
* object and are not nulls.
*
* @since 10.0 (previously, subclasses would override equivalent())
*/
protected abstract boolean doEquivalent(T a, T b);
/**
* Returns a hash code for {@code t}.
*
* <p>The {@code hash} has the following properties:
* <ul>
* <li>It is <i>consistent</i>: for any reference {@code x}, multiple invocations of
* {@code hash(x}} consistently return the same value provided {@code x} remains unchanged
* according to the definition of the equivalence. The hash need not remain consistent from
* one execution of an application to another execution of the same application.
* <li>It is <i>distributable accross equivalence</i>: for any references {@code x} and {@code y},
* if {@code equivalent(x, y)}, then {@code hash(x) == hash(y)}. It is <i>not</i> necessary
* that the hash be distributable accorss <i>inequivalence</i>. If {@code equivalence(x, y)}
* is false, {@code hash(x) == hash(y)} may still be true.
* <li>{@code hash(null)} is {@code 0}.
* </ul>
*/
public final int hash(@Nullable T t) {
if (t == null) {
return 0;
}
return doHash(t);
}
/**
* Returns a hash code for non-null object {@code t}.
*
* <p>Called by {@link #hash}.
*
* @since 10.0 (previously, subclasses would override hash())
*/
protected abstract int doHash(T t);
/**
* Returns a new equivalence relation for {@code F} which evaluates equivalence by first applying
* {@code function} to the argument, then evaluating using {@code this}. That is, for any pair of
* non-null objects {@code x} and {@code y}, {@code
* equivalence.onResultOf(function).equivalent(a, b)} is true if and only if {@code
* equivalence.equivalent(function.apply(a), function.apply(b))} is true.
*
* <p>For example: <pre> {@code
*
* Equivalence<Person> SAME_AGE = Equivalences.equals().onResultOf(GET_PERSON_AGE);
* }</pre>
*
* <p>{@code function} will never be invoked with a null value.
*
* <p>Note that {@code function} must be consistent according to {@code this} equivalence
* relation. That is, invoking {@link Function#apply} multiple times for a given value must return
* equivalent results.
* For example, {@code Equivalences.identity().onResultOf(Functions.toStringFunction())} is broken
* because it's not guaranteed that {@link Object#toString}) always returns the same string
* instance.
*
* @since 10.0
*/
public final <F> Equivalence<F> onResultOf(Function<F, ? extends T> function) {
return new FunctionalEquivalence<F, T>(function, this);
}
/**
* Returns a wrapper of {@code reference} that implements
* {@link Wrapper#equals(Object) Object.equals()} such that
* {@code wrap(this, a).equals(wrap(this, b))} if and only if {@code this.equivalent(a, b)}.
*
* @since 10.0
*/
public final <S extends T> Wrapper<S> wrap(@Nullable S reference) {
return new Wrapper<S>(this, reference);
}
/**
* Wraps an object so that {@link #equals(Object)} and {@link #hashCode()} delegate to an
* {@link Equivalence}.
*
* <p>For example, given an {@link Equivalence} for {@link String strings} named {@code equiv}
* that tests equivalence using their lengths:
*
* <pre> {@code
* equiv.wrap("a").equals(equiv.wrap("b")) // true
* equiv.wrap("a").equals(equiv.wrap("hello")) // false
* }</pre>
*
* <p>Note in particular that an equivalence wrapper is never equal to the object it wraps.
*
* <pre> {@code
* equiv.wrap(obj).equals(obj) // always false
* }</pre>
*
* @since 10.0
*/
@Beta
public static final class Wrapper<T> implements Serializable {
private final Equivalence<? super T> equivalence;
@Nullable private final T reference;
private Wrapper(Equivalence<? super T> equivalence, @Nullable T reference) {
this.equivalence = checkNotNull(equivalence);
this.reference = reference;
}
/** Returns the (possibly null) reference wrapped by this instance. */
@Nullable public T get() {
return reference;
}
/**
* Returns {@code true} if {@link Equivalence#equivalent(Object, Object)} applied to the wrapped
* references is {@code true} and both wrappers use the {@link Object#equals(Object) same}
* equivalence.
*/
@Override public boolean equals(@Nullable Object obj) {
if (obj == this) {
return true;
} else if (obj instanceof Wrapper) {
Wrapper<?> that = (Wrapper<?>) obj;
/*
* We cast to Equivalence<Object> here because we can't check the type of the reference held
* by the other wrapper. But, by checking that the Equivalences are equal, we know that
* whatever type it is, it is assignable to the type handled by this wrapper's equivalence.
*/
@SuppressWarnings("unchecked")
Equivalence<Object> equivalence = (Equivalence<Object>) this.equivalence;
return equivalence.equals(that.equivalence)
&& equivalence.equivalent(this.reference, that.reference);
} else {
return false;
}
}
/**
* Returns the result of {@link Equivalence#hash(Object)} applied to the the wrapped reference.
*/
@Override public int hashCode() {
return equivalence.hash(reference);
}
/**
* Returns a string representation for this equivalence wrapper. The form of this string
* representation is not specified.
*/
@Override public String toString() {
return equivalence + ".wrap(" + reference + ")";
}
private static final long serialVersionUID = 0;
}
/**
* Returns an equivalence over iterables based on the equivalence of their elements. More
* specifically, two iterables are considered equivalent if they both contain the same number of
* elements, and each pair of corresponding elements is equivalent according to
* {@code this}. Null iterables are equivalent to one another.
*
* <p>Note that this method performs a similar function for equivalences as {@link
* com.google.common.collect.Ordering#lexicographical} does for orderings.
*
* @since 10.0
*/
@GwtCompatible(serializable = true)
public final <S extends T> Equivalence<Iterable<S>> pairwise() {
// Ideally, the returned equivalence would support Iterable<? extends T>. However,
// the need for this is so rare that it's not worth making callers deal with the ugly wildcard.
return new PairwiseEquivalence<S>(this);
}
/**
* Returns a predicate that evaluates to true if and only if the input is
* equivalent to {@code target} according to this equivalence relation.
*
* @since 10.0
*/
public final Predicate<T> equivalentTo(@Nullable T target) {
return new EquivalentToPredicate<T>(this, target);
}
private static final class EquivalentToPredicate<T> implements Predicate<T>, Serializable {
private final Equivalence<T> equivalence;
@Nullable private final T target;
EquivalentToPredicate(Equivalence<T> equivalence, @Nullable T target) {
this.equivalence = checkNotNull(equivalence);
this.target = target;
}
@Override public boolean apply(@Nullable T input) {
return equivalence.equivalent(input, target);
}
@Override public boolean equals(@Nullable Object obj) {
if (this == obj) {
return true;
}
if (obj instanceof EquivalentToPredicate) {
EquivalentToPredicate<?> that = (EquivalentToPredicate<?>) obj;
return equivalence.equals(that.equivalence)
&& Objects.equal(target, that.target);
}
return false;
}
@Override public int hashCode() {
return Objects.hashCode(equivalence, target);
}
@Override public String toString() {
return equivalence + ".equivalentTo(" + target + ")";
}
private static final long serialVersionUID = 0;
}
}
| Java |
/*
* Copyright (C) 2007 The Guava Authors
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package com.google.common.base;
import static com.google.common.base.Preconditions.checkArgument;
import static com.google.common.base.Preconditions.checkNotNull;
import com.google.common.annotations.Beta;
import com.google.common.annotations.GwtCompatible;
import java.io.Serializable;
import java.util.Map;
import javax.annotation.Nullable;
/**
* Static utility methods pertaining to {@code Function} instances.
*
* <p>All methods return serializable functions as long as they're given serializable parameters.
*
* <p>See the Guava User Guide article on <a href=
* "http://code.google.com/p/guava-libraries/wiki/FunctionalExplained">the use of {@code
* Function}</a>.
*
* @author Mike Bostock
* @author Jared Levy
* @since 2.0 (imported from Google Collections Library)
*/
@GwtCompatible
public final class Functions {
private Functions() {}
/**
* Returns a function that calls {@code toString()} on its argument. The function does not accept
* nulls; it will throw a {@link NullPointerException} when applied to {@code null}.
*
* <p><b>Warning:</b> The returned function may not be <i>consistent with equals</i> (as
* documented at {@link Function#apply}). For example, this function yields different results for
* the two equal instances {@code ImmutableSet.of(1, 2)} and {@code ImmutableSet.of(2, 1)}.
*/
public static Function<Object, String> toStringFunction() {
return ToStringFunction.INSTANCE;
}
// enum singleton pattern
private enum ToStringFunction implements Function<Object, String> {
INSTANCE;
@Override
public String apply(Object o) {
checkNotNull(o); // eager for GWT.
return o.toString();
}
@Override public String toString() {
return "toString";
}
}
/**
* Returns the identity function.
*/
@SuppressWarnings("unchecked")
public static <E> Function<E, E> identity() {
return (Function<E, E>) IdentityFunction.INSTANCE;
}
// enum singleton pattern
private enum IdentityFunction implements Function<Object, Object> {
INSTANCE;
@Override
public Object apply(Object o) {
return o;
}
@Override public String toString() {
return "identity";
}
}
/**
* Returns a function which performs a map lookup. The returned function throws an {@link
* IllegalArgumentException} if given a key that does not exist in the map.
*/
public static <K, V> Function<K, V> forMap(Map<K, V> map) {
return new FunctionForMapNoDefault<K, V>(map);
}
private static class FunctionForMapNoDefault<K, V> implements Function<K, V>, Serializable {
final Map<K, V> map;
FunctionForMapNoDefault(Map<K, V> map) {
this.map = checkNotNull(map);
}
@Override
public V apply(K key) {
V result = map.get(key);
checkArgument(result != null || map.containsKey(key), "Key '%s' not present in map", key);
return result;
}
@Override public boolean equals(@Nullable Object o) {
if (o instanceof FunctionForMapNoDefault) {
FunctionForMapNoDefault<?, ?> that = (FunctionForMapNoDefault<?, ?>) o;
return map.equals(that.map);
}
return false;
}
@Override public int hashCode() {
return map.hashCode();
}
@Override public String toString() {
return "forMap(" + map + ")";
}
private static final long serialVersionUID = 0;
}
/**
* Returns a function which performs a map lookup with a default value. The function created by
* this method returns {@code defaultValue} for all inputs that do not belong to the map's key
* set.
*
* @param map source map that determines the function behavior
* @param defaultValue the value to return for inputs that aren't map keys
* @return function that returns {@code map.get(a)} when {@code a} is a key, or {@code
* defaultValue} otherwise
*/
public static <K, V> Function<K, V> forMap(Map<K, ? extends V> map, @Nullable V defaultValue) {
return new ForMapWithDefault<K, V>(map, defaultValue);
}
private static class ForMapWithDefault<K, V> implements Function<K, V>, Serializable {
final Map<K, ? extends V> map;
final V defaultValue;
ForMapWithDefault(Map<K, ? extends V> map, @Nullable V defaultValue) {
this.map = checkNotNull(map);
this.defaultValue = defaultValue;
}
@Override
public V apply(K key) {
V result = map.get(key);
return (result != null || map.containsKey(key)) ? result : defaultValue;
}
@Override public boolean equals(@Nullable Object o) {
if (o instanceof ForMapWithDefault) {
ForMapWithDefault<?, ?> that = (ForMapWithDefault<?, ?>) o;
return map.equals(that.map) && Objects.equal(defaultValue, that.defaultValue);
}
return false;
}
@Override public int hashCode() {
return Objects.hashCode(map, defaultValue);
}
@Override public String toString() {
return "forMap(" + map + ", defaultValue=" + defaultValue + ")";
}
private static final long serialVersionUID = 0;
}
/**
* Returns the composition of two functions. For {@code f: A->B} and {@code g: B->C}, composition
* is defined as the function h such that {@code h(a) == g(f(a))} for each {@code a}.
*
* @param g the second function to apply
* @param f the first function to apply
* @return the composition of {@code f} and {@code g}
* @see <a href="//en.wikipedia.org/wiki/Function_composition">function composition</a>
*/
public static <A, B, C> Function<A, C> compose(Function<B, C> g, Function<A, ? extends B> f) {
return new FunctionComposition<A, B, C>(g, f);
}
private static class FunctionComposition<A, B, C> implements Function<A, C>, Serializable {
private final Function<B, C> g;
private final Function<A, ? extends B> f;
public FunctionComposition(Function<B, C> g, Function<A, ? extends B> f) {
this.g = checkNotNull(g);
this.f = checkNotNull(f);
}
@Override
public C apply(A a) {
return g.apply(f.apply(a));
}
@Override public boolean equals(@Nullable Object obj) {
if (obj instanceof FunctionComposition) {
FunctionComposition<?, ?, ?> that = (FunctionComposition<?, ?, ?>) obj;
return f.equals(that.f) && g.equals(that.g);
}
return false;
}
@Override public int hashCode() {
return f.hashCode() ^ g.hashCode();
}
@Override public String toString() {
return g.toString() + "(" + f.toString() + ")";
}
private static final long serialVersionUID = 0;
}
/**
* Creates a function that returns the same boolean output as the given predicate for all inputs.
*
* <p>The returned function is <i>consistent with equals</i> (as documented at {@link
* Function#apply}) if and only if {@code predicate} is itself consistent with equals.
*/
public static <T> Function<T, Boolean> forPredicate(Predicate<T> predicate) {
return new PredicateFunction<T>(predicate);
}
/** @see Functions#forPredicate */
private static class PredicateFunction<T> implements Function<T, Boolean>, Serializable {
private final Predicate<T> predicate;
private PredicateFunction(Predicate<T> predicate) {
this.predicate = checkNotNull(predicate);
}
@Override
public Boolean apply(T t) {
return predicate.apply(t);
}
@Override public boolean equals(@Nullable Object obj) {
if (obj instanceof PredicateFunction) {
PredicateFunction<?> that = (PredicateFunction<?>) obj;
return predicate.equals(that.predicate);
}
return false;
}
@Override public int hashCode() {
return predicate.hashCode();
}
@Override public String toString() {
return "forPredicate(" + predicate + ")";
}
private static final long serialVersionUID = 0;
}
/**
* Creates a function that returns {@code value} for any input.
*
* @param value the constant value for the function to return
* @return a function that always returns {@code value}
*/
public static <E> Function<Object, E> constant(@Nullable E value) {
return new ConstantFunction<E>(value);
}
private static class ConstantFunction<E> implements Function<Object, E>, Serializable {
private final E value;
public ConstantFunction(@Nullable E value) {
this.value = value;
}
@Override
public E apply(@Nullable Object from) {
return value;
}
@Override public boolean equals(@Nullable Object obj) {
if (obj instanceof ConstantFunction) {
ConstantFunction<?> that = (ConstantFunction<?>) obj;
return Objects.equal(value, that.value);
}
return false;
}
@Override public int hashCode() {
return (value == null) ? 0 : value.hashCode();
}
@Override public String toString() {
return "constant(" + value + ")";
}
private static final long serialVersionUID = 0;
}
/**
* Returns a function that always returns the result of invoking {@link Supplier#get} on {@code
* supplier}, regardless of its input.
*
* @since 10.0
*/
@Beta
public static <T> Function<Object, T> forSupplier(Supplier<T> supplier) {
return new SupplierFunction<T>(supplier);
}
/** @see Functions#forSupplier*/
private static class SupplierFunction<T> implements Function<Object, T>, Serializable {
private final Supplier<T> supplier;
private SupplierFunction(Supplier<T> supplier) {
this.supplier = checkNotNull(supplier);
}
@Override public T apply(@Nullable Object input) {
return supplier.get();
}
@Override public boolean equals(@Nullable Object obj) {
if (obj instanceof SupplierFunction) {
SupplierFunction<?> that = (SupplierFunction<?>) obj;
return this.supplier.equals(that.supplier);
}
return false;
}
@Override public int hashCode() {
return supplier.hashCode();
}
@Override public String toString() {
return "forSupplier(" + supplier + ")";
}
private static final long serialVersionUID = 0;
}
}
| Java |
/*
* Copyright (C) 2009 The Guava Authors
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package com.google.common.base;
import static com.google.common.base.Preconditions.checkArgument;
import static com.google.common.base.Preconditions.checkNotNull;
import com.google.common.annotations.Beta;
import com.google.common.annotations.GwtCompatible;
import com.google.common.annotations.GwtIncompatible;
import java.util.Collections;
import java.util.Iterator;
import java.util.LinkedHashMap;
import java.util.Map;
import java.util.regex.Matcher;
import java.util.regex.Pattern;
import javax.annotation.CheckReturnValue;
/**
* An object that divides strings (or other instances of {@code CharSequence})
* into substrings, by recognizing a <i>separator</i> (a.k.a. "delimiter")
* which can be expressed as a single character, literal string, regular
* expression, {@code CharMatcher}, or by using a fixed substring length. This
* class provides the complementary functionality to {@link Joiner}.
*
* <p>Here is the most basic example of {@code Splitter} usage: <pre> {@code
*
* Splitter.on(',').split("foo,bar")}</pre>
*
* This invocation returns an {@code Iterable<String>} containing {@code "foo"}
* and {@code "bar"}, in that order.
*
* <p>By default {@code Splitter}'s behavior is very simplistic: <pre> {@code
*
* Splitter.on(',').split("foo,,bar, quux")}</pre>
*
* This returns an iterable containing {@code ["foo", "", "bar", " quux"]}.
* Notice that the splitter does not assume that you want empty strings removed,
* or that you wish to trim whitespace. If you want features like these, simply
* ask for them: <pre> {@code
*
* private static final Splitter MY_SPLITTER = Splitter.on(',')
* .trimResults()
* .omitEmptyStrings();}</pre>
*
* Now {@code MY_SPLITTER.split("foo, ,bar, quux,")} returns an iterable
* containing just {@code ["foo", "bar", "quux"]}. Note that the order in which
* the configuration methods are called is never significant; for instance,
* trimming is always applied first before checking for an empty result,
* regardless of the order in which the {@link #trimResults()} and
* {@link #omitEmptyStrings()} methods were invoked.
*
* <p><b>Warning: splitter instances are always immutable</b>; a configuration
* method such as {@code omitEmptyStrings} has no effect on the instance it
* is invoked on! You must store and use the new splitter instance returned by
* the method. This makes splitters thread-safe, and safe to store as {@code
* static final} constants (as illustrated above). <pre> {@code
*
* // Bad! Do not do this!
* Splitter splitter = Splitter.on('/');
* splitter.trimResults(); // does nothing!
* return splitter.split("wrong / wrong / wrong");}</pre>
*
* The separator recognized by the splitter does not have to be a single
* literal character as in the examples above. See the methods {@link
* #on(String)}, {@link #on(Pattern)} and {@link #on(CharMatcher)} for examples
* of other ways to specify separators.
*
* <p><b>Note:</b> this class does not mimic any of the quirky behaviors of
* similar JDK methods; for instance, it does not silently discard trailing
* separators, as does {@link String#split(String)}, nor does it have a default
* behavior of using five particular whitespace characters as separators, like
* {@link java.util.StringTokenizer}.
*
* <p>See the Guava User Guide article on <a href=
* "http://code.google.com/p/guava-libraries/wiki/StringsExplained#Splitter">
* {@code Splitter}</a>.
*
* @author Julien Silland
* @author Jesse Wilson
* @author Kevin Bourrillion
* @author Louis Wasserman
* @since 1.0
*/
@GwtCompatible(emulated = true)
public final class Splitter {
private final CharMatcher trimmer;
private final boolean omitEmptyStrings;
private final Strategy strategy;
private final int limit;
private Splitter(Strategy strategy) {
this(strategy, false, CharMatcher.NONE, Integer.MAX_VALUE);
}
private Splitter(Strategy strategy, boolean omitEmptyStrings,
CharMatcher trimmer, int limit) {
this.strategy = strategy;
this.omitEmptyStrings = omitEmptyStrings;
this.trimmer = trimmer;
this.limit = limit;
}
/**
* Returns a splitter that uses the given single-character separator. For
* example, {@code Splitter.on(',').split("foo,,bar")} returns an iterable
* containing {@code ["foo", "", "bar"]}.
*
* @param separator the character to recognize as a separator
* @return a splitter, with default settings, that recognizes that separator
*/
public static Splitter on(char separator) {
return on(CharMatcher.is(separator));
}
/**
* Returns a splitter that considers any single character matched by the
* given {@code CharMatcher} to be a separator. For example, {@code
* Splitter.on(CharMatcher.anyOf(";,")).split("foo,;bar,quux")} returns an
* iterable containing {@code ["foo", "", "bar", "quux"]}.
*
* @param separatorMatcher a {@link CharMatcher} that determines whether a
* character is a separator
* @return a splitter, with default settings, that uses this matcher
*/
public static Splitter on(final CharMatcher separatorMatcher) {
checkNotNull(separatorMatcher);
return new Splitter(new Strategy() {
@Override public SplittingIterator iterator(
Splitter splitter, final CharSequence toSplit) {
return new SplittingIterator(splitter, toSplit) {
@Override int separatorStart(int start) {
return separatorMatcher.indexIn(toSplit, start);
}
@Override int separatorEnd(int separatorPosition) {
return separatorPosition + 1;
}
};
}
});
}
/**
* Returns a splitter that uses the given fixed string as a separator. For
* example, {@code Splitter.on(", ").split("foo, bar, baz,qux")} returns an
* iterable containing {@code ["foo", "bar", "baz,qux"]}.
*
* @param separator the literal, nonempty string to recognize as a separator
* @return a splitter, with default settings, that recognizes that separator
*/
public static Splitter on(final String separator) {
checkArgument(separator.length() != 0,
"The separator may not be the empty string.");
return new Splitter(new Strategy() {
@Override public SplittingIterator iterator(
Splitter splitter, CharSequence toSplit) {
return new SplittingIterator(splitter, toSplit) {
@Override public int separatorStart(int start) {
int delimeterLength = separator.length();
positions:
for (int p = start, last = toSplit.length() - delimeterLength;
p <= last; p++) {
for (int i = 0; i < delimeterLength; i++) {
if (toSplit.charAt(i + p) != separator.charAt(i)) {
continue positions;
}
}
return p;
}
return -1;
}
@Override public int separatorEnd(int separatorPosition) {
return separatorPosition + separator.length();
}
};
}
});
}
/**
* Returns a splitter that considers any subsequence matching {@code
* pattern} to be a separator. For example, {@code
* Splitter.on(Pattern.compile("\r?\n")).split(entireFile)} splits a string
* into lines whether it uses DOS-style or UNIX-style line terminators.
*
* @param separatorPattern the pattern that determines whether a subsequence
* is a separator. This pattern may not match the empty string.
* @return a splitter, with default settings, that uses this pattern
* @throws IllegalArgumentException if {@code separatorPattern} matches the
* empty string
*/
@GwtIncompatible("java.util.regex")
public static Splitter on(final Pattern separatorPattern) {
checkNotNull(separatorPattern);
checkArgument(!separatorPattern.matcher("").matches(),
"The pattern may not match the empty string: %s", separatorPattern);
return new Splitter(new Strategy() {
@Override public SplittingIterator iterator(
final Splitter splitter, CharSequence toSplit) {
final Matcher matcher = separatorPattern.matcher(toSplit);
return new SplittingIterator(splitter, toSplit) {
@Override public int separatorStart(int start) {
return matcher.find(start) ? matcher.start() : -1;
}
@Override public int separatorEnd(int separatorPosition) {
return matcher.end();
}
};
}
});
}
/**
* Returns a splitter that considers any subsequence matching a given
* pattern (regular expression) to be a separator. For example, {@code
* Splitter.onPattern("\r?\n").split(entireFile)} splits a string into lines
* whether it uses DOS-style or UNIX-style line terminators. This is
* equivalent to {@code Splitter.on(Pattern.compile(pattern))}.
*
* @param separatorPattern the pattern that determines whether a subsequence
* is a separator. This pattern may not match the empty string.
* @return a splitter, with default settings, that uses this pattern
* @throws java.util.regex.PatternSyntaxException if {@code separatorPattern}
* is a malformed expression
* @throws IllegalArgumentException if {@code separatorPattern} matches the
* empty string
*/
@GwtIncompatible("java.util.regex")
public static Splitter onPattern(String separatorPattern) {
return on(Pattern.compile(separatorPattern));
}
/**
* Returns a splitter that divides strings into pieces of the given length.
* For example, {@code Splitter.fixedLength(2).split("abcde")} returns an
* iterable containing {@code ["ab", "cd", "e"]}. The last piece can be
* smaller than {@code length} but will never be empty.
*
* @param length the desired length of pieces after splitting
* @return a splitter, with default settings, that can split into fixed sized
* pieces
*/
public static Splitter fixedLength(final int length) {
checkArgument(length > 0, "The length may not be less than 1");
return new Splitter(new Strategy() {
@Override public SplittingIterator iterator(
final Splitter splitter, CharSequence toSplit) {
return new SplittingIterator(splitter, toSplit) {
@Override public int separatorStart(int start) {
int nextChunkStart = start + length;
return (nextChunkStart < toSplit.length() ? nextChunkStart : -1);
}
@Override public int separatorEnd(int separatorPosition) {
return separatorPosition;
}
};
}
});
}
/**
* Returns a splitter that behaves equivalently to {@code this} splitter, but
* automatically omits empty strings from the results. For example, {@code
* Splitter.on(',').omitEmptyStrings().split(",a,,,b,c,,")} returns an
* iterable containing only {@code ["a", "b", "c"]}.
*
* <p>If either {@code trimResults} option is also specified when creating a
* splitter, that splitter always trims results first before checking for
* emptiness. So, for example, {@code
* Splitter.on(':').omitEmptyStrings().trimResults().split(": : : ")} returns
* an empty iterable.
*
* <p>Note that it is ordinarily not possible for {@link #split(CharSequence)}
* to return an empty iterable, but when using this option, it can (if the
* input sequence consists of nothing but separators).
*
* @return a splitter with the desired configuration
*/
@CheckReturnValue
public Splitter omitEmptyStrings() {
return new Splitter(strategy, true, trimmer, limit);
}
/**
* Returns a splitter that behaves equivalently to {@code this} splitter but
* stops splitting after it reaches the limit.
* The limit defines the maximum number of items returned by the iterator.
*
* <p>For example,
* {@code Splitter.on(',').limit(3).split("a,b,c,d")} returns an iterable
* containing {@code ["a", "b", "c,d"]}. When omitting empty strings, the
* omitted strings do no count. Hence,
* {@code Splitter.on(',').limit(3).omitEmptyStrings().split("a,,,b,,,c,d")}
* returns an iterable containing {@code ["a", "b", "c,d"}.
* When trim is requested, all entries, including the last are trimmed. Hence
* {@code Splitter.on(',').limit(3).trimResults().split(" a , b , c , d ")}
* results in @{code ["a", "b", "c , d"]}.
*
* @param limit the maximum number of items returns
* @return a splitter with the desired configuration
* @since 9.0
*/
@CheckReturnValue
public Splitter limit(int limit) {
checkArgument(limit > 0, "must be greater than zero: %s", limit);
return new Splitter(strategy, omitEmptyStrings, trimmer, limit);
}
/**
* Returns a splitter that behaves equivalently to {@code this} splitter, but
* automatically removes leading and trailing {@linkplain
* CharMatcher#WHITESPACE whitespace} from each returned substring; equivalent
* to {@code trimResults(CharMatcher.WHITESPACE)}. For example, {@code
* Splitter.on(',').trimResults().split(" a, b ,c ")} returns an iterable
* containing {@code ["a", "b", "c"]}.
*
* @return a splitter with the desired configuration
*/
@CheckReturnValue
public Splitter trimResults() {
return trimResults(CharMatcher.WHITESPACE);
}
/**
* Returns a splitter that behaves equivalently to {@code this} splitter, but
* removes all leading or trailing characters matching the given {@code
* CharMatcher} from each returned substring. For example, {@code
* Splitter.on(',').trimResults(CharMatcher.is('_')).split("_a ,_b_ ,c__")}
* returns an iterable containing {@code ["a ", "b_ ", "c"]}.
*
* @param trimmer a {@link CharMatcher} that determines whether a character
* should be removed from the beginning/end of a subsequence
* @return a splitter with the desired configuration
*/
// TODO(kevinb): throw if a trimmer was already specified!
@CheckReturnValue
public Splitter trimResults(CharMatcher trimmer) {
checkNotNull(trimmer);
return new Splitter(strategy, omitEmptyStrings, trimmer, limit);
}
/**
* Splits {@code sequence} into string components and makes them available
* through an {@link Iterator}, which may be lazily evaluated.
*
* @param sequence the sequence of characters to split
* @return an iteration over the segments split from the parameter.
*/
public Iterable<String> split(final CharSequence sequence) {
checkNotNull(sequence);
return new Iterable<String>() {
@Override public Iterator<String> iterator() {
return spliterator(sequence);
}
};
}
private Iterator<String> spliterator(CharSequence sequence) {
return strategy.iterator(this, sequence);
}
/**
* Returns a {@code MapSplitter} which splits entries based on this splitter,
* and splits entries into keys and values using the specified separator.
*
* @since 10.0
*/
@CheckReturnValue
@Beta
public MapSplitter withKeyValueSeparator(String separator) {
return withKeyValueSeparator(on(separator));
}
/**
* Returns a {@code MapSplitter} which splits entries based on this splitter,
* and splits entries into keys and values using the specified key-value
* splitter.
*
* @since 10.0
*/
@CheckReturnValue
@Beta
public MapSplitter withKeyValueSeparator(Splitter keyValueSplitter) {
return new MapSplitter(this, keyValueSplitter);
}
/**
* An object that splits strings into maps as {@code Splitter} splits
* iterables and lists. Like {@code Splitter}, it is thread-safe and
* immutable.
*
* @since 10.0
*/
@Beta
public static final class MapSplitter {
private static final String INVALID_ENTRY_MESSAGE =
"Chunk [%s] is not a valid entry";
private final Splitter outerSplitter;
private final Splitter entrySplitter;
private MapSplitter(Splitter outerSplitter, Splitter entrySplitter) {
this.outerSplitter = outerSplitter; // only "this" is passed
this.entrySplitter = checkNotNull(entrySplitter);
}
/**
* Splits {@code sequence} into substrings, splits each substring into
* an entry, and returns an unmodifiable map with each of the entries. For
* example, <code>
* Splitter.on(';').trimResults().withKeyValueSeparator("=>")
* .split("a=>b ; c=>b")
* </code> will return a mapping from {@code "a"} to {@code "b"} and
* {@code "c"} to {@code b}.
*
* <p>The returned map preserves the order of the entries from
* {@code sequence}.
*
* @throws IllegalArgumentException if the specified sequence does not split
* into valid map entries, or if there are duplicate keys
*/
public Map<String, String> split(CharSequence sequence) {
Map<String, String> map = new LinkedHashMap<String, String>();
for (String entry : outerSplitter.split(sequence)) {
Iterator<String> entryFields = entrySplitter.spliterator(entry);
checkArgument(entryFields.hasNext(), INVALID_ENTRY_MESSAGE, entry);
String key = entryFields.next();
checkArgument(!map.containsKey(key), "Duplicate key [%s] found.", key);
checkArgument(entryFields.hasNext(), INVALID_ENTRY_MESSAGE, entry);
String value = entryFields.next();
map.put(key, value);
checkArgument(!entryFields.hasNext(), INVALID_ENTRY_MESSAGE, entry);
}
return Collections.unmodifiableMap(map);
}
}
private interface Strategy {
Iterator<String> iterator(Splitter splitter, CharSequence toSplit);
}
private abstract static class SplittingIterator
extends AbstractIterator<String> {
final CharSequence toSplit;
final CharMatcher trimmer;
final boolean omitEmptyStrings;
/**
* Returns the first index in {@code toSplit} at or after {@code start}
* that contains the separator.
*/
abstract int separatorStart(int start);
/**
* Returns the first index in {@code toSplit} after {@code
* separatorPosition} that does not contain a separator. This method is only
* invoked after a call to {@code separatorStart}.
*/
abstract int separatorEnd(int separatorPosition);
int offset = 0;
int limit;
protected SplittingIterator(Splitter splitter, CharSequence toSplit) {
this.trimmer = splitter.trimmer;
this.omitEmptyStrings = splitter.omitEmptyStrings;
this.limit = splitter.limit;
this.toSplit = toSplit;
}
@Override protected String computeNext() {
while (offset != -1) {
int start = offset;
int end;
int separatorPosition = separatorStart(offset);
if (separatorPosition == -1) {
end = toSplit.length();
offset = -1;
} else {
end = separatorPosition;
offset = separatorEnd(separatorPosition);
}
while (start < end && trimmer.matches(toSplit.charAt(start))) {
start++;
}
while (end > start && trimmer.matches(toSplit.charAt(end - 1))) {
end--;
}
if (omitEmptyStrings && start == end) {
continue;
}
if (limit == 1) {
// The limit has been reached, return the rest of the string as the
// final item. This is tested after empty string removal so that
// empty strings do not count towards the limit.
end = toSplit.length();
offset = -1;
// Since we may have changed the end, we need to trim it again.
while (end > start && trimmer.matches(toSplit.charAt(end - 1))) {
end--;
}
} else {
limit--;
}
return toSplit.subSequence(start, end).toString();
}
return endOfData();
}
}
}
| Java |
/*
* Copyright (C) 2007 The Guava Authors
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package com.google.common.base;
import com.google.common.annotations.GwtCompatible;
import javax.annotation.Nullable;
/**
* Determines a true or false value for a given input.
*
* <p>See the Guava User Guide article on <a href=
* "http://code.google.com/p/guava-libraries/wiki/FunctionalExplained">the use of {@code
* Predicate}</a>.
*
* @author Kevin Bourrillion
* @since 2.0 (imported from Google Collections Library)
*/
@GwtCompatible
public interface Predicate<T> {
/**
* Returns the result of applying this predicate to {@code input}. This method is <i>generally
* expected</i>, but not absolutely required, to have the following properties:
*
* <ul>
* <li>Its execution does not cause any observable side effects.
* <li>The computation is <i>consistent with equals</i>; that is, {@link Objects#equal
* Objects.equal}{@code (a, b)} implies that {@code predicate.apply(a) ==
* predicate.apply(b))}.
* </ul>
*
* @throws NullPointerException if {@code input} is null and this predicate does not accept null
* arguments
*/
boolean apply(@Nullable T input);
/**
* Indicates whether another object is equal to this predicate.
*
* <p>Most implementations will have no reason to override the behavior of {@link Object#equals}.
* However, an implementation may also choose to return {@code true} whenever {@code object} is a
* {@link Predicate} that it considers <i>interchangeable</i> with this one. "Interchangeable"
* <i>typically</i> means that {@code this.apply(t) == that.apply(t)} for all {@code t} of type
* {@code T}). Note that a {@code false} result from this method does not imply that the
* predicates are known <i>not</i> to be interchangeable.
*/
@Override
boolean equals(@Nullable Object object);
}
| Java |
/*
* Copyright (C) 2007 The Guava Authors
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package com.google.common.base;
import com.google.common.annotations.GwtCompatible;
import javax.annotation.Nullable;
/**
* Determines an output value based on an input value.
*
* <p>See the Guava User Guide article on <a href=
* "http://code.google.com/p/guava-libraries/wiki/FunctionalExplained">the use of {@code
* Function}</a>.
*
* @author Kevin Bourrillion
* @since 2.0 (imported from Google Collections Library)
*/
@GwtCompatible
public interface Function<F, T> {
/**
* Returns the result of applying this function to {@code input}. This method is <i>generally
* expected</i>, but not absolutely required, to have the following properties:
*
* <ul>
* <li>Its execution does not cause any observable side effects.
* <li>The computation is <i>consistent with equals</i>; that is, {@link Objects#equal
* Objects.equal}{@code (a, b)} implies that {@code Objects.equal(function.apply(a),
* function.apply(b))}.
* </ul>
*
* @throws NullPointerException if {@code input} is null and this function does not accept null
* arguments
*/
T apply(@Nullable F input);
/**
* Indicates whether another object is equal to this function.
*
* <p>Most implementations will have no reason to override the behavior of {@link Object#equals}.
* However, an implementation may also choose to return {@code true} whenever {@code object} is a
* {@link Function} that it considers <i>interchangeable</i> with this one. "Interchangeable"
* <i>typically</i> means that {@code Objects.equal(this.apply(f), that.apply(f))} is true for all
* {@code f} of type {@code F}. Note that a {@code false} result from this method does not imply
* that the functions are known <i>not</i> to be interchangeable.
*/
@Override
boolean equals(@Nullable Object object);
}
| Java |
/*
* Copyright (C) 2008 The Guava Authors
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package com.google.common.base;
import static com.google.common.base.Preconditions.checkArgument;
import static com.google.common.base.Preconditions.checkNotNull;
import com.google.common.annotations.Beta;
import com.google.common.annotations.GwtCompatible;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.List;
import javax.annotation.CheckReturnValue;
/**
* Determines a true or false value for any Java {@code char} value, just as {@link Predicate} does
* for any {@link Object}. Also offers basic text processing methods based on this function.
* Implementations are strongly encouraged to be side-effect-free and immutable.
*
* <p>Throughout the documentation of this class, the phrase "matching character" is used to mean
* "any character {@code c} for which {@code this.matches(c)} returns {@code true}".
*
* <p><b>Note:</b> This class deals only with {@code char} values; it does not understand
* supplementary Unicode code points in the range {@code 0x10000} to {@code 0x10FFFF}. Such logical
* characters are encoded into a {@code String} using surrogate pairs, and a {@code CharMatcher}
* treats these just as two separate characters.
*
* <p>Example usages: <pre>
* String trimmed = {@link #WHITESPACE WHITESPACE}.{@link #trimFrom trimFrom}(userInput);
* if ({@link #ASCII ASCII}.{@link #matchesAllOf matchesAllOf}(s)) { ... }</pre>
*
* <p>See the Guava User Guide article on <a href=
* "http://code.google.com/p/guava-libraries/wiki/StringsExplained#CharMatcher">
* {@code CharMatcher}</a>.
*
* @author Kevin Bourrillion
* @since 1.0
*/
@Beta // Possibly change from chars to code points; decide constants vs. methods
@GwtCompatible
public abstract class CharMatcher implements Predicate<Character> {
// Constants
// Excludes 2000-2000a, which is handled as a range
private static final String BREAKING_WHITESPACE_CHARS =
"\t\n\013\f\r \u0085\u1680\u2028\u2029\u205f\u3000";
// Excludes 2007, which is handled as a gap in a pair of ranges
private static final String NON_BREAKING_WHITESPACE_CHARS =
"\u00a0\u180e\u202f";
/**
* Determines whether a character is whitespace according to the latest Unicode standard, as
* illustrated
* <a href="http://unicode.org/cldr/utility/list-unicodeset.jsp?a=%5Cp%7Bwhitespace%7D">here</a>.
* This is not the same definition used by other Java APIs. (See a
* <a href="http://spreadsheets.google.com/pub?key=pd8dAQyHbdewRsnE5x5GzKQ">comparison of several
* definitions of "whitespace"</a>.)
*
* <p><b>Note:</b> as the Unicode definition evolves, we will modify this constant to keep it up
* to date.
*/
public static final CharMatcher WHITESPACE =
anyOf(BREAKING_WHITESPACE_CHARS + NON_BREAKING_WHITESPACE_CHARS)
.or(inRange('\u2000', '\u200a'))
.withToString("CharMatcher.WHITESPACE")
.precomputed();
/**
* Determines whether a character is a breaking whitespace (that is, a whitespace which can be
* interpreted as a break between words for formatting purposes). See {@link #WHITESPACE} for a
* discussion of that term.
*
* @since 2.0
*/
public static final CharMatcher BREAKING_WHITESPACE =
anyOf(BREAKING_WHITESPACE_CHARS)
.or(inRange('\u2000', '\u2006'))
.or(inRange('\u2008', '\u200a'))
.withToString("CharMatcher.BREAKING_WHITESPACE")
.precomputed();
/**
* Determines whether a character is ASCII, meaning that its code point is less than 128.
*/
public static final CharMatcher ASCII = inRange('\0', '\u007f')
.withToString("CharMatcher.ASCII");
/**
* Determines whether a character is a digit according to
* <a href="http://unicode.org/cldr/utility/list-unicodeset.jsp?a=%5Cp%7Bdigit%7D">Unicode</a>.
*/
public static final CharMatcher DIGIT;
static {
CharMatcher digit = inRange('0', '9');
String zeroes =
"\u0660\u06f0\u07c0\u0966\u09e6\u0a66\u0ae6\u0b66\u0be6\u0c66"
+ "\u0ce6\u0d66\u0e50\u0ed0\u0f20\u1040\u1090\u17e0\u1810\u1946"
+ "\u19d0\u1b50\u1bb0\u1c40\u1c50\ua620\ua8d0\ua900\uaa50\uff10";
for (char base : zeroes.toCharArray()) {
digit = digit.or(inRange(base, (char) (base + 9)));
}
DIGIT = digit.withToString("CharMatcher.DIGIT").precomputed();
}
/**
* Determines whether a character is a digit according to {@link Character#isDigit(char) Java's
* definition}. If you only care to match ASCII digits, you can use {@code inRange('0', '9')}.
*/
public static final CharMatcher JAVA_DIGIT = new CharMatcher() {
@Override public boolean matches(char c) {
return Character.isDigit(c);
}
@Override public String toString() {
return "CharMatcher.JAVA_DIGIT";
}
};
/**
* Determines whether a character is a letter according to {@link Character#isLetter(char) Java's
* definition}. If you only care to match letters of the Latin alphabet, you can use {@code
* inRange('a', 'z').or(inRange('A', 'Z'))}.
*/
public static final CharMatcher JAVA_LETTER = new CharMatcher() {
@Override public boolean matches(char c) {
return Character.isLetter(c);
}
@Override public String toString() {
return "CharMatcher.JAVA_LETTER";
}
};
/**
* Determines whether a character is a letter or digit according to {@link
* Character#isLetterOrDigit(char) Java's definition}.
*/
public static final CharMatcher JAVA_LETTER_OR_DIGIT = new CharMatcher() {
@Override public boolean matches(char c) {
return Character.isLetterOrDigit(c);
}
@Override public String toString() {
return "CharMatcher.JAVA_LETTER_OR_DIGIT";
}
};
/**
* Determines whether a character is upper case according to {@link Character#isUpperCase(char)
* Java's definition}.
*/
public static final CharMatcher JAVA_UPPER_CASE = new CharMatcher() {
@Override public boolean matches(char c) {
return Character.isUpperCase(c);
}
@Override public String toString() {
return "CharMatcher.JAVA_UPPER_CASE";
}
};
/**
* Determines whether a character is lower case according to {@link Character#isLowerCase(char)
* Java's definition}.
*/
public static final CharMatcher JAVA_LOWER_CASE = new CharMatcher() {
@Override public boolean matches(char c) {
return Character.isLowerCase(c);
}
@Override public String toString() {
return "CharMatcher.JAVA_LOWER_CASE";
}
};
/**
* Determines whether a character is an ISO control character as specified by {@link
* Character#isISOControl(char)}.
*/
public static final CharMatcher JAVA_ISO_CONTROL =
inRange('\u0000', '\u001f').or(inRange('\u007f', '\u009f'))
.withToString("CharMatcher.JAVA_ISO_CONTROL");
/**
* Determines whether a character is invisible; that is, if its Unicode category is any of
* SPACE_SEPARATOR, LINE_SEPARATOR, PARAGRAPH_SEPARATOR, CONTROL, FORMAT, SURROGATE, and
* PRIVATE_USE according to ICU4J.
*/
public static final CharMatcher INVISIBLE = inRange('\u0000', '\u0020')
.or(inRange('\u007f', '\u00a0'))
.or(is('\u00ad'))
.or(inRange('\u0600', '\u0603'))
.or(anyOf("\u06dd\u070f\u1680\u17b4\u17b5\u180e"))
.or(inRange('\u2000', '\u200f'))
.or(inRange('\u2028', '\u202f'))
.or(inRange('\u205f', '\u2064'))
.or(inRange('\u206a', '\u206f'))
.or(is('\u3000'))
.or(inRange('\ud800', '\uf8ff'))
.or(anyOf("\ufeff\ufff9\ufffa\ufffb"))
.withToString("CharMatcher.INVISIBLE")
.precomputed();
/**
* Determines whether a character is single-width (not double-width). When in doubt, this matcher
* errs on the side of returning {@code false} (that is, it tends to assume a character is
* double-width).
*
* <p><b>Note:</b> as the reference file evolves, we will modify this constant to keep it up to
* date.
*/
public static final CharMatcher SINGLE_WIDTH = inRange('\u0000', '\u04f9')
.or(is('\u05be'))
.or(inRange('\u05d0', '\u05ea'))
.or(is('\u05f3'))
.or(is('\u05f4'))
.or(inRange('\u0600', '\u06ff'))
.or(inRange('\u0750', '\u077f'))
.or(inRange('\u0e00', '\u0e7f'))
.or(inRange('\u1e00', '\u20af'))
.or(inRange('\u2100', '\u213a'))
.or(inRange('\ufb50', '\ufdff'))
.or(inRange('\ufe70', '\ufeff'))
.or(inRange('\uff61', '\uffdc'))
.withToString("CharMatcher.SINGLE_WIDTH")
.precomputed();
/** Matches any character. */
public static final CharMatcher ANY =
new CharMatcher() {
@Override public boolean matches(char c) {
return true;
}
@Override public int indexIn(CharSequence sequence) {
return (sequence.length() == 0) ? -1 : 0;
}
@Override public int indexIn(CharSequence sequence, int start) {
int length = sequence.length();
Preconditions.checkPositionIndex(start, length);
return (start == length) ? -1 : start;
}
@Override public int lastIndexIn(CharSequence sequence) {
return sequence.length() - 1;
}
@Override public boolean matchesAllOf(CharSequence sequence) {
checkNotNull(sequence);
return true;
}
@Override public boolean matchesNoneOf(CharSequence sequence) {
return sequence.length() == 0;
}
@Override public String removeFrom(CharSequence sequence) {
checkNotNull(sequence);
return "";
}
@Override public String replaceFrom(CharSequence sequence, char replacement) {
char[] array = new char[sequence.length()];
Arrays.fill(array, replacement);
return new String(array);
}
@Override public String replaceFrom(CharSequence sequence, CharSequence replacement) {
StringBuilder retval = new StringBuilder(sequence.length() * replacement.length());
for (int i = 0; i < sequence.length(); i++) {
retval.append(replacement);
}
return retval.toString();
}
@Override public String collapseFrom(CharSequence sequence, char replacement) {
return (sequence.length() == 0) ? "" : String.valueOf(replacement);
}
@Override public String trimFrom(CharSequence sequence) {
checkNotNull(sequence);
return "";
}
@Override public int countIn(CharSequence sequence) {
return sequence.length();
}
@Override public CharMatcher and(CharMatcher other) {
return checkNotNull(other);
}
@Override public CharMatcher or(CharMatcher other) {
checkNotNull(other);
return this;
}
@Override public CharMatcher negate() {
return NONE;
}
@Override public CharMatcher precomputed() {
return this;
}
@Override public String toString() {
return "CharMatcher.ANY";
}
};
/** Matches no characters. */
public static final CharMatcher NONE =
new CharMatcher() {
@Override public boolean matches(char c) {
return false;
}
@Override public int indexIn(CharSequence sequence) {
checkNotNull(sequence);
return -1;
}
@Override public int indexIn(CharSequence sequence, int start) {
int length = sequence.length();
Preconditions.checkPositionIndex(start, length);
return -1;
}
@Override public int lastIndexIn(CharSequence sequence) {
checkNotNull(sequence);
return -1;
}
@Override public boolean matchesAllOf(CharSequence sequence) {
return sequence.length() == 0;
}
@Override public boolean matchesNoneOf(CharSequence sequence) {
checkNotNull(sequence);
return true;
}
@Override public String removeFrom(CharSequence sequence) {
return sequence.toString();
}
@Override public String replaceFrom(CharSequence sequence, char replacement) {
return sequence.toString();
}
@Override public String replaceFrom(CharSequence sequence, CharSequence replacement) {
checkNotNull(replacement);
return sequence.toString();
}
@Override public String collapseFrom(CharSequence sequence, char replacement) {
return sequence.toString();
}
@Override public String trimFrom(CharSequence sequence) {
return sequence.toString();
}
@Override public int countIn(CharSequence sequence) {
checkNotNull(sequence);
return 0;
}
@Override public CharMatcher and(CharMatcher other) {
checkNotNull(other);
return this;
}
@Override public CharMatcher or(CharMatcher other) {
return checkNotNull(other);
}
@Override public CharMatcher negate() {
return ANY;
}
@Override void setBits(LookupTable table) {}
@Override public CharMatcher precomputed() {
return this;
}
@Override public String toString() {
return "CharMatcher.NONE";
}
};
// Static factories
/**
* Returns a {@code char} matcher that matches only one specified character.
*/
public static CharMatcher is(final char match) {
return new CharMatcher() {
@Override public boolean matches(char c) {
return c == match;
}
@Override public String replaceFrom(CharSequence sequence, char replacement) {
return sequence.toString().replace(match, replacement);
}
@Override public CharMatcher and(CharMatcher other) {
return other.matches(match) ? this : NONE;
}
@Override public CharMatcher or(CharMatcher other) {
return other.matches(match) ? other : super.or(other);
}
@Override public CharMatcher negate() {
return isNot(match);
}
@Override void setBits(LookupTable table) {
table.set(match);
}
@Override public CharMatcher precomputed() {
return this;
}
@Override public String toString() {
return new StringBuilder("CharMatcher.is(")
.append(Integer.toHexString(match))
.append(")")
.toString();
}
};
}
/**
* Returns a {@code char} matcher that matches any character except the one specified.
*
* <p>To negate another {@code CharMatcher}, use {@link #negate()}.
*/
public static CharMatcher isNot(final char match) {
return new CharMatcher() {
@Override public boolean matches(char c) {
return c != match;
}
@Override public CharMatcher and(CharMatcher other) {
return other.matches(match) ? super.and(other) : other;
}
@Override public CharMatcher or(CharMatcher other) {
return other.matches(match) ? ANY : this;
}
@Override public CharMatcher negate() {
return is(match);
}
@Override public String toString() {
return new StringBuilder("CharMatcher.isNot(")
.append(Integer.toHexString(match))
.append(")")
.toString();
}
};
}
/**
* Returns a {@code char} matcher that matches any character present in the given character
* sequence.
*/
public static CharMatcher anyOf(final CharSequence sequence) {
switch (sequence.length()) {
case 0:
return NONE;
case 1:
return is(sequence.charAt(0));
case 2:
final char match1 = sequence.charAt(0);
final char match2 = sequence.charAt(1);
return new CharMatcher() {
@Override public boolean matches(char c) {
return c == match1 || c == match2;
}
@Override void setBits(LookupTable table) {
table.set(match1);
table.set(match2);
}
@Override public CharMatcher precomputed() {
return this;
}
};
}
final char[] chars = sequence.toString().toCharArray();
Arrays.sort(chars); // not worth collapsing duplicates
return new CharMatcher() {
@Override public boolean matches(char c) {
return Arrays.binarySearch(chars, c) >= 0;
}
@Override void setBits(LookupTable table) {
for (char c : chars) {
table.set(c);
}
}
@Override public String toString() {
return new StringBuilder("CharMatcher.anyOf(\"").append(chars).append("\")").toString();
}
};
}
/**
* Returns a {@code char} matcher that matches any character not present in the given character
* sequence.
*/
public static CharMatcher noneOf(CharSequence sequence) {
return anyOf(sequence).negate();
}
/**
* Returns a {@code char} matcher that matches any character in a given range (both endpoints are
* inclusive). For example, to match any lowercase letter of the English alphabet, use {@code
* CharMatcher.inRange('a', 'z')}.
*
* @throws IllegalArgumentException if {@code endInclusive < startInclusive}
*/
public static CharMatcher inRange(final char startInclusive, final char endInclusive) {
checkArgument(endInclusive >= startInclusive);
return new CharMatcher() {
@Override public boolean matches(char c) {
return startInclusive <= c && c <= endInclusive;
}
@Override void setBits(LookupTable table) {
char c = startInclusive;
while (true) {
table.set(c);
if (c++ == endInclusive) {
break;
}
}
}
@Override public CharMatcher precomputed() {
return this;
}
@Override public String toString() {
return new StringBuilder("CharMatcher.inRange(")
.append(Integer.toHexString(startInclusive))
.append(", ")
.append(Integer.toHexString(endInclusive))
.append(")")
.toString();
}
};
}
/**
* Returns a matcher with identical behavior to the given {@link Character}-based predicate, but
* which operates on primitive {@code char} instances instead.
*/
public static CharMatcher forPredicate(final Predicate<? super Character> predicate) {
checkNotNull(predicate);
if (predicate instanceof CharMatcher) {
return (CharMatcher) predicate;
}
return new CharMatcher() {
@Override public boolean matches(char c) {
return predicate.apply(c);
}
@Override public boolean apply(Character character) {
return predicate.apply(checkNotNull(character));
}
@Override public String toString() {
return new StringBuilder("CharMatcher.forPredicate(")
.append(predicate)
.append(')')
.toString();
}
};
}
// Constructors
/**
* Constructor for use by subclasses.
*/
protected CharMatcher() {}
// Abstract methods
/** Determines a true or false value for the given character. */
public abstract boolean matches(char c);
// Non-static factories
/**
* Returns a matcher that matches any character not matched by this matcher.
*/
public CharMatcher negate() {
final CharMatcher original = this;
return new CharMatcher() {
@Override public boolean matches(char c) {
return !original.matches(c);
}
@Override public boolean matchesAllOf(CharSequence sequence) {
return original.matchesNoneOf(sequence);
}
@Override public boolean matchesNoneOf(CharSequence sequence) {
return original.matchesAllOf(sequence);
}
@Override public int countIn(CharSequence sequence) {
return sequence.length() - original.countIn(sequence);
}
@Override public CharMatcher negate() {
return original;
}
@Override public String toString() {
return original + ".negate()";
}
};
}
/**
* Returns a matcher that matches any character matched by both this matcher and {@code other}.
*/
public CharMatcher and(CharMatcher other) {
return new And(Arrays.asList(this, checkNotNull(other)));
}
private static class And extends CharMatcher {
List<CharMatcher> components;
And(List<CharMatcher> components) {
this.components = components; // Skip defensive copy (private)
}
@Override public boolean matches(char c) {
for (CharMatcher matcher : components) {
if (!matcher.matches(c)) {
return false;
}
}
return true;
}
@Override public CharMatcher and(CharMatcher other) {
List<CharMatcher> newComponents = new ArrayList<CharMatcher>(components);
newComponents.add(checkNotNull(other));
return new And(newComponents);
}
@Override public String toString() {
StringBuilder builder = new StringBuilder("CharMatcher.and(");
Joiner.on(", ").appendTo(builder, components);
return builder.append(')').toString();
}
}
/**
* Returns a matcher that matches any character matched by either this matcher or {@code other}.
*/
public CharMatcher or(CharMatcher other) {
return new Or(Arrays.asList(this, checkNotNull(other)));
}
private static class Or extends CharMatcher {
List<CharMatcher> components;
Or(List<CharMatcher> components) {
this.components = components; // Skip defensive copy (private)
}
@Override public boolean matches(char c) {
for (CharMatcher matcher : components) {
if (matcher.matches(c)) {
return true;
}
}
return false;
}
@Override public CharMatcher or(CharMatcher other) {
List<CharMatcher> newComponents = new ArrayList<CharMatcher>(components);
newComponents.add(checkNotNull(other));
return new Or(newComponents);
}
@Override void setBits(LookupTable table) {
for (CharMatcher matcher : components) {
matcher.setBits(table);
}
}
@Override public String toString() {
StringBuilder builder = new StringBuilder("CharMatcher.or(");
Joiner.on(", ").appendTo(builder, components);
return builder.append(')').toString();
}
}
/**
* Returns a {@code char} matcher functionally equivalent to this one, but which may be faster to
* query than the original; your mileage may vary. Precomputation takes time and is likely to be
* worthwhile only if the precomputed matcher is queried many thousands of times.
*
* <p>This method has no effect (returns {@code this}) when called in GWT: it's unclear whether a
* precomputed matcher is faster, but it certainly consumes more memory, which doesn't seem like a
* worthwhile tradeoff in a browser.
*/
public CharMatcher precomputed() {
return Platform.precomputeCharMatcher(this);
}
/**
* This is the actual implementation of {@link #precomputed}, but we bounce calls through a method
* on {@link Platform} so that we can have different behavior in GWT.
*
* <p>The default precomputation is to cache the configuration of the original matcher in an
* eight-kilobyte bit array. In some situations this produces a matcher which is faster to query
* than the original.
*
* <p>The default implementation creates a new bit array and passes it to {@link
* #setBits(LookupTable)}.
*/
CharMatcher precomputedInternal() {
final LookupTable table = new LookupTable();
setBits(table);
final CharMatcher outer = this;
return new CharMatcher() {
@Override public boolean matches(char c) {
return table.get(c);
}
// TODO(kevinb): make methods like negate() smart?
@Override public CharMatcher precomputed() {
return this;
}
@Override public String toString() {
return outer.toString();
}
};
}
CharMatcher withToString(final String toString) {
final CharMatcher delegate = this;
return new CharMatcher() {
@Override
public boolean matches(char c) {
return delegate.matches(c);
}
@Override
void setBits(LookupTable table) {
delegate.setBits(table);
}
@Override
public String toString() {
return toString;
}
};
}
/**
* For use by implementors; sets the bit corresponding to each character ('\0' to '{@literal
* \}uFFFF') that matches this matcher in the given bit array, leaving all other bits untouched.
*
* <p>The default implementation loops over every possible character value, invoking {@link
* #matches} for each one.
*/
void setBits(LookupTable table) {
char c = Character.MIN_VALUE;
while (true) {
if (matches(c)) {
table.set(c);
}
if (c++ == Character.MAX_VALUE) {
break;
}
}
}
/**
* A bit array with one bit per {@code char} value, used by {@link CharMatcher#precomputed}.
*
* <p>TODO(kevinb): possibly share a common BitArray class with BloomFilter and others... a
* simpler java.util.BitSet.
*/
private static final class LookupTable {
int[] data = new int[2048];
void set(char index) {
data[index >> 5] |= (1 << index);
}
boolean get(char index) {
return (data[index >> 5] & (1 << index)) != 0;
}
}
// Text processing routines
/**
* Returns {@code true} if a character sequence contains at least one matching character.
* Equivalent to {@code !matchesNoneOf(sequence)}.
*
* <p>The default implementation iterates over the sequence, invoking {@link #matches} for each
* character, until this returns {@code true} or the end is reached.
*
* @param sequence the character sequence to examine, possibly empty
* @return {@code true} if this matcher matches at least one character in the sequence
* @since 8.0
*/
public boolean matchesAnyOf(CharSequence sequence) {
return !matchesNoneOf(sequence);
}
/**
* Returns {@code true} if a character sequence contains only matching characters.
*
* <p>The default implementation iterates over the sequence, invoking {@link #matches} for each
* character, until this returns {@code false} or the end is reached.
*
* @param sequence the character sequence to examine, possibly empty
* @return {@code true} if this matcher matches every character in the sequence, including when
* the sequence is empty
*/
public boolean matchesAllOf(CharSequence sequence) {
for (int i = sequence.length() - 1; i >= 0; i--) {
if (!matches(sequence.charAt(i))) {
return false;
}
}
return true;
}
/**
* Returns {@code true} if a character sequence contains no matching characters. Equivalent to
* {@code !matchesAnyOf(sequence)}.
*
* <p>The default implementation iterates over the sequence, invoking {@link #matches} for each
* character, until this returns {@code false} or the end is reached.
*
* @param sequence the character sequence to examine, possibly empty
* @return {@code true} if this matcher matches every character in the sequence, including when
* the sequence is empty
*/
public boolean matchesNoneOf(CharSequence sequence) {
return indexIn(sequence) == -1;
}
// TODO(kevinb): add matchesAnyOf()
/**
* Returns the index of the first matching character in a character sequence, or {@code -1} if no
* matching character is present.
*
* <p>The default implementation iterates over the sequence in forward order calling {@link
* #matches} for each character.
*
* @param sequence the character sequence to examine from the beginning
* @return an index, or {@code -1} if no character matches
*/
public int indexIn(CharSequence sequence) {
int length = sequence.length();
for (int i = 0; i < length; i++) {
if (matches(sequence.charAt(i))) {
return i;
}
}
return -1;
}
/**
* Returns the index of the first matching character in a character sequence, starting from a
* given position, or {@code -1} if no character matches after that position.
*
* <p>The default implementation iterates over the sequence in forward order, beginning at {@code
* start}, calling {@link #matches} for each character.
*
* @param sequence the character sequence to examine
* @param start the first index to examine; must be nonnegative and no greater than {@code
* sequence.length()}
* @return the index of the first matching character, guaranteed to be no less than {@code start},
* or {@code -1} if no character matches
* @throws IndexOutOfBoundsException if start is negative or greater than {@code
* sequence.length()}
*/
public int indexIn(CharSequence sequence, int start) {
int length = sequence.length();
Preconditions.checkPositionIndex(start, length);
for (int i = start; i < length; i++) {
if (matches(sequence.charAt(i))) {
return i;
}
}
return -1;
}
/**
* Returns the index of the last matching character in a character sequence, or {@code -1} if no
* matching character is present.
*
* <p>The default implementation iterates over the sequence in reverse order calling {@link
* #matches} for each character.
*
* @param sequence the character sequence to examine from the end
* @return an index, or {@code -1} if no character matches
*/
public int lastIndexIn(CharSequence sequence) {
for (int i = sequence.length() - 1; i >= 0; i--) {
if (matches(sequence.charAt(i))) {
return i;
}
}
return -1;
}
/**
* Returns the number of matching characters found in a character sequence.
*/
public int countIn(CharSequence sequence) {
int count = 0;
for (int i = 0; i < sequence.length(); i++) {
if (matches(sequence.charAt(i))) {
count++;
}
}
return count;
}
/**
* Returns a string containing all non-matching characters of a character sequence, in order. For
* example: <pre> {@code
*
* CharMatcher.is('a').removeFrom("bazaar")}</pre>
*
* ... returns {@code "bzr"}.
*/
@CheckReturnValue
public String removeFrom(CharSequence sequence) {
String string = sequence.toString();
int pos = indexIn(string);
if (pos == -1) {
return string;
}
char[] chars = string.toCharArray();
int spread = 1;
// This unusual loop comes from extensive benchmarking
OUT: while (true) {
pos++;
while (true) {
if (pos == chars.length) {
break OUT;
}
if (matches(chars[pos])) {
break;
}
chars[pos - spread] = chars[pos];
pos++;
}
spread++;
}
return new String(chars, 0, pos - spread);
}
/**
* Returns a string containing all matching characters of a character sequence, in order. For
* example: <pre> {@code
*
* CharMatcher.is('a').retainFrom("bazaar")}</pre>
*
* ... returns {@code "aaa"}.
*/
@CheckReturnValue
public String retainFrom(CharSequence sequence) {
return negate().removeFrom(sequence);
}
/**
* Returns a string copy of the input character sequence, with each character that matches this
* matcher replaced by a given replacement character. For example: <pre> {@code
*
* CharMatcher.is('a').replaceFrom("radar", 'o')}</pre>
*
* ... returns {@code "rodor"}.
*
* <p>The default implementation uses {@link #indexIn(CharSequence)} to find the first matching
* character, then iterates the remainder of the sequence calling {@link #matches(char)} for each
* character.
*
* @param sequence the character sequence to replace matching characters in
* @param replacement the character to append to the result string in place of each matching
* character in {@code sequence}
* @return the new string
*/
@CheckReturnValue
public String replaceFrom(CharSequence sequence, char replacement) {
String string = sequence.toString();
int pos = indexIn(string);
if (pos == -1) {
return string;
}
char[] chars = string.toCharArray();
chars[pos] = replacement;
for (int i = pos + 1; i < chars.length; i++) {
if (matches(chars[i])) {
chars[i] = replacement;
}
}
return new String(chars);
}
/**
* Returns a string copy of the input character sequence, with each character that matches this
* matcher replaced by a given replacement sequence. For example: <pre> {@code
*
* CharMatcher.is('a').replaceFrom("yaha", "oo")}</pre>
*
* ... returns {@code "yoohoo"}.
*
* <p><b>Note:</b> If the replacement is a fixed string with only one character, you are better
* off calling {@link #replaceFrom(CharSequence, char)} directly.
*
* @param sequence the character sequence to replace matching characters in
* @param replacement the characters to append to the result string in place of each matching
* character in {@code sequence}
* @return the new string
*/
@CheckReturnValue
public String replaceFrom(CharSequence sequence, CharSequence replacement) {
int replacementLen = replacement.length();
if (replacementLen == 0) {
return removeFrom(sequence);
}
if (replacementLen == 1) {
return replaceFrom(sequence, replacement.charAt(0));
}
String string = sequence.toString();
int pos = indexIn(string);
if (pos == -1) {
return string;
}
int len = string.length();
StringBuilder buf = new StringBuilder((len * 3 / 2) + 16);
int oldpos = 0;
do {
buf.append(string, oldpos, pos);
buf.append(replacement);
oldpos = pos + 1;
pos = indexIn(string, oldpos);
} while (pos != -1);
buf.append(string, oldpos, len);
return buf.toString();
}
/**
* Returns a substring of the input character sequence that omits all characters this matcher
* matches from the beginning and from the end of the string. For example: <pre> {@code
*
* CharMatcher.anyOf("ab").trimFrom("abacatbab")}</pre>
*
* ... returns {@code "cat"}.
*
* <p>Note that: <pre> {@code
*
* CharMatcher.inRange('\0', ' ').trimFrom(str)}</pre>
*
* ... is equivalent to {@link String#trim()}.
*/
@CheckReturnValue
public String trimFrom(CharSequence sequence) {
int len = sequence.length();
int first;
int last;
for (first = 0; first < len; first++) {
if (!matches(sequence.charAt(first))) {
break;
}
}
for (last = len - 1; last > first; last--) {
if (!matches(sequence.charAt(last))) {
break;
}
}
return sequence.subSequence(first, last + 1).toString();
}
/**
* Returns a substring of the input character sequence that omits all characters this matcher
* matches from the beginning of the string. For example: <pre> {@code
*
* CharMatcher.anyOf("ab").trimLeadingFrom("abacatbab")}</pre>
*
* ... returns {@code "catbab"}.
*/
@CheckReturnValue
public String trimLeadingFrom(CharSequence sequence) {
int len = sequence.length();
int first;
for (first = 0; first < len; first++) {
if (!matches(sequence.charAt(first))) {
break;
}
}
return sequence.subSequence(first, len).toString();
}
/**
* Returns a substring of the input character sequence that omits all characters this matcher
* matches from the end of the string. For example: <pre> {@code
*
* CharMatcher.anyOf("ab").trimTrailingFrom("abacatbab")}</pre>
*
* ... returns {@code "abacat"}.
*/
@CheckReturnValue
public String trimTrailingFrom(CharSequence sequence) {
int len = sequence.length();
int last;
for (last = len - 1; last >= 0; last--) {
if (!matches(sequence.charAt(last))) {
break;
}
}
return sequence.subSequence(0, last + 1).toString();
}
/**
* Returns a string copy of the input character sequence, with each group of consecutive
* characters that match this matcher replaced by a single replacement character. For example:
* <pre> {@code
*
* CharMatcher.anyOf("eko").collapseFrom("bookkeeper", '-')}</pre>
*
* ... returns {@code "b-p-r"}.
*
* <p>The default implementation uses {@link #indexIn(CharSequence)} to find the first matching
* character, then iterates the remainder of the sequence calling {@link #matches(char)} for each
* character.
*
* @param sequence the character sequence to replace matching groups of characters in
* @param replacement the character to append to the result string in place of each group of
* matching characters in {@code sequence}
* @return the new string
*/
@CheckReturnValue
public String collapseFrom(CharSequence sequence, char replacement) {
int first = indexIn(sequence);
if (first == -1) {
return sequence.toString();
}
// TODO(kevinb): see if this implementation can be made faster
StringBuilder builder = new StringBuilder(sequence.length())
.append(sequence.subSequence(0, first))
.append(replacement);
boolean in = true;
for (int i = first + 1; i < sequence.length(); i++) {
char c = sequence.charAt(i);
if (apply(c)) {
if (!in) {
builder.append(replacement);
in = true;
}
} else {
builder.append(c);
in = false;
}
}
return builder.toString();
}
/**
* Collapses groups of matching characters exactly as {@link #collapseFrom} does, except that
* groups of matching characters at the start or end of the sequence are removed without
* replacement.
*/
@CheckReturnValue
public String trimAndCollapseFrom(CharSequence sequence, char replacement) {
int first = negate().indexIn(sequence);
if (first == -1) {
return ""; // everything matches. nothing's left.
}
StringBuilder builder = new StringBuilder(sequence.length());
boolean inMatchingGroup = false;
for (int i = first; i < sequence.length(); i++) {
char c = sequence.charAt(i);
if (apply(c)) {
inMatchingGroup = true;
} else {
if (inMatchingGroup) {
builder.append(replacement);
inMatchingGroup = false;
}
builder.append(c);
}
}
return builder.toString();
}
// Predicate interface
/**
* Returns {@code true} if this matcher matches the given character.
*
* @throws NullPointerException if {@code character} is null
*/
@Override public boolean apply(Character character) {
return matches(character);
}
/**
* Returns a string representation of this {@code CharMatcher}, such as
* {@code CharMatcher.or(WHITESPACE, JAVA_DIGIT)}.
*/
@Override
public String toString() {
return super.toString();
}
}
| Java |
/*
* Copyright (C) 2007 The Guava Authors
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package com.google.common.base;
import com.google.common.annotations.GwtCompatible;
import com.google.common.annotations.VisibleForTesting;
import java.util.NoSuchElementException;
import javax.annotation.Nullable;
/**
* Simple static methods to be called at the start of your own methods to verify
* correct arguments and state. This allows constructs such as
* <pre>
* if (count <= 0) {
* throw new IllegalArgumentException("must be positive: " + count);
* }</pre>
*
* to be replaced with the more compact
* <pre>
* checkArgument(count > 0, "must be positive: %s", count);</pre>
*
* Note that the sense of the expression is inverted; with {@code Preconditions}
* you declare what you expect to be <i>true</i>, just as you do with an
* <a href="http://java.sun.com/j2se/1.5.0/docs/guide/language/assert.html">
* {@code assert}</a> or a JUnit {@code assertTrue} call.
*
* <p><b>Warning:</b> only the {@code "%s"} specifier is recognized as a
* placeholder in these messages, not the full range of {@link
* String#format(String, Object[])} specifiers.
*
* <p>Take care not to confuse precondition checking with other similar types
* of checks! Precondition exceptions -- including those provided here, but also
* {@link IndexOutOfBoundsException}, {@link NoSuchElementException}, {@link
* UnsupportedOperationException} and others -- are used to signal that the
* <i>calling method</i> has made an error. This tells the caller that it should
* not have invoked the method when it did, with the arguments it did, or
* perhaps ever. Postcondition or other invariant failures should not throw
* these types of exceptions.
*
* <p>See the Guava User Guide on <a href=
* "http://code.google.com/p/guava-libraries/wiki/PreconditionsExplained">
* using {@code Preconditions}</a>.
*
* @author Kevin Bourrillion
* @since 2.0 (imported from Google Collections Library)
*/
@GwtCompatible
public final class Preconditions {
private Preconditions() {}
/**
* Ensures the truth of an expression involving one or more parameters to the
* calling method.
*
* @param expression a boolean expression
* @throws IllegalArgumentException if {@code expression} is false
*/
public static void checkArgument(boolean expression) {
if (!expression) {
throw new IllegalArgumentException();
}
}
/**
* Ensures the truth of an expression involving one or more parameters to the
* calling method.
*
* @param expression a boolean expression
* @param errorMessage the exception message to use if the check fails; will
* be converted to a string using {@link String#valueOf(Object)}
* @throws IllegalArgumentException if {@code expression} is false
*/
public static void checkArgument(
boolean expression, @Nullable Object errorMessage) {
if (!expression) {
throw new IllegalArgumentException(String.valueOf(errorMessage));
}
}
/**
* Ensures the truth of an expression involving one or more parameters to the
* calling method.
*
* @param expression a boolean expression
* @param errorMessageTemplate a template for the exception message should the
* check fail. The message is formed by replacing each {@code %s}
* placeholder in the template with an argument. These are matched by
* position - the first {@code %s} gets {@code errorMessageArgs[0]}, etc.
* Unmatched arguments will be appended to the formatted message in square
* braces. Unmatched placeholders will be left as-is.
* @param errorMessageArgs the arguments to be substituted into the message
* template. Arguments are converted to strings using
* {@link String#valueOf(Object)}.
* @throws IllegalArgumentException if {@code expression} is false
* @throws NullPointerException if the check fails and either {@code
* errorMessageTemplate} or {@code errorMessageArgs} is null (don't let
* this happen)
*/
public static void checkArgument(boolean expression,
@Nullable String errorMessageTemplate,
@Nullable Object... errorMessageArgs) {
if (!expression) {
throw new IllegalArgumentException(
format(errorMessageTemplate, errorMessageArgs));
}
}
/**
* Ensures the truth of an expression involving the state of the calling
* instance, but not involving any parameters to the calling method.
*
* @param expression a boolean expression
* @throws IllegalStateException if {@code expression} is false
*/
public static void checkState(boolean expression) {
if (!expression) {
throw new IllegalStateException();
}
}
/**
* Ensures the truth of an expression involving the state of the calling
* instance, but not involving any parameters to the calling method.
*
* @param expression a boolean expression
* @param errorMessage the exception message to use if the check fails; will
* be converted to a string using {@link String#valueOf(Object)}
* @throws IllegalStateException if {@code expression} is false
*/
public static void checkState(
boolean expression, @Nullable Object errorMessage) {
if (!expression) {
throw new IllegalStateException(String.valueOf(errorMessage));
}
}
/**
* Ensures the truth of an expression involving the state of the calling
* instance, but not involving any parameters to the calling method.
*
* @param expression a boolean expression
* @param errorMessageTemplate a template for the exception message should the
* check fail. The message is formed by replacing each {@code %s}
* placeholder in the template with an argument. These are matched by
* position - the first {@code %s} gets {@code errorMessageArgs[0]}, etc.
* Unmatched arguments will be appended to the formatted message in square
* braces. Unmatched placeholders will be left as-is.
* @param errorMessageArgs the arguments to be substituted into the message
* template. Arguments are converted to strings using
* {@link String#valueOf(Object)}.
* @throws IllegalStateException if {@code expression} is false
* @throws NullPointerException if the check fails and either {@code
* errorMessageTemplate} or {@code errorMessageArgs} is null (don't let
* this happen)
*/
public static void checkState(boolean expression,
@Nullable String errorMessageTemplate,
@Nullable Object... errorMessageArgs) {
if (!expression) {
throw new IllegalStateException(
format(errorMessageTemplate, errorMessageArgs));
}
}
/**
* Ensures that an object reference passed as a parameter to the calling
* method is not null.
*
* @param reference an object reference
* @return the non-null reference that was validated
* @throws NullPointerException if {@code reference} is null
*/
public static <T> T checkNotNull(T reference) {
if (reference == null) {
throw new NullPointerException();
}
return reference;
}
/**
* Ensures that an object reference passed as a parameter to the calling
* method is not null.
*
* @param reference an object reference
* @param errorMessage the exception message to use if the check fails; will
* be converted to a string using {@link String#valueOf(Object)}
* @return the non-null reference that was validated
* @throws NullPointerException if {@code reference} is null
*/
public static <T> T checkNotNull(T reference, @Nullable Object errorMessage) {
if (reference == null) {
throw new NullPointerException(String.valueOf(errorMessage));
}
return reference;
}
/**
* Ensures that an object reference passed as a parameter to the calling
* method is not null.
*
* @param reference an object reference
* @param errorMessageTemplate a template for the exception message should the
* check fail. The message is formed by replacing each {@code %s}
* placeholder in the template with an argument. These are matched by
* position - the first {@code %s} gets {@code errorMessageArgs[0]}, etc.
* Unmatched arguments will be appended to the formatted message in square
* braces. Unmatched placeholders will be left as-is.
* @param errorMessageArgs the arguments to be substituted into the message
* template. Arguments are converted to strings using
* {@link String#valueOf(Object)}.
* @return the non-null reference that was validated
* @throws NullPointerException if {@code reference} is null
*/
public static <T> T checkNotNull(T reference,
@Nullable String errorMessageTemplate,
@Nullable Object... errorMessageArgs) {
if (reference == null) {
// If either of these parameters is null, the right thing happens anyway
throw new NullPointerException(
format(errorMessageTemplate, errorMessageArgs));
}
return reference;
}
/*
* All recent hotspots (as of 2009) *really* like to have the natural code
*
* if (guardExpression) {
* throw new BadException(messageExpression);
* }
*
* refactored so that messageExpression is moved to a separate
* String-returning method.
*
* if (guardExpression) {
* throw new BadException(badMsg(...));
* }
*
* The alternative natural refactorings into void or Exception-returning
* methods are much slower. This is a big deal - we're talking factors of
* 2-8 in microbenchmarks, not just 10-20%. (This is a hotspot optimizer
* bug, which should be fixed, but that's a separate, big project).
*
* The coding pattern above is heavily used in java.util, e.g. in ArrayList.
* There is a RangeCheckMicroBenchmark in the JDK that was used to test this.
*
* But the methods in this class want to throw different exceptions,
* depending on the args, so it appears that this pattern is not directly
* applicable. But we can use the ridiculous, devious trick of throwing an
* exception in the middle of the construction of another exception.
* Hotspot is fine with that.
*/
/**
* Ensures that {@code index} specifies a valid <i>element</i> in an array,
* list or string of size {@code size}. An element index may range from zero,
* inclusive, to {@code size}, exclusive.
*
* @param index a user-supplied index identifying an element of an array, list
* or string
* @param size the size of that array, list or string
* @return the value of {@code index}
* @throws IndexOutOfBoundsException if {@code index} is negative or is not
* less than {@code size}
* @throws IllegalArgumentException if {@code size} is negative
*/
public static int checkElementIndex(int index, int size) {
return checkElementIndex(index, size, "index");
}
/**
* Ensures that {@code index} specifies a valid <i>element</i> in an array,
* list or string of size {@code size}. An element index may range from zero,
* inclusive, to {@code size}, exclusive.
*
* @param index a user-supplied index identifying an element of an array, list
* or string
* @param size the size of that array, list or string
* @param desc the text to use to describe this index in an error message
* @return the value of {@code index}
* @throws IndexOutOfBoundsException if {@code index} is negative or is not
* less than {@code size}
* @throws IllegalArgumentException if {@code size} is negative
*/
public static int checkElementIndex(
int index, int size, @Nullable String desc) {
// Carefully optimized for execution by hotspot (explanatory comment above)
if (index < 0 || index >= size) {
throw new IndexOutOfBoundsException(badElementIndex(index, size, desc));
}
return index;
}
private static String badElementIndex(int index, int size, String desc) {
if (index < 0) {
return format("%s (%s) must not be negative", desc, index);
} else if (size < 0) {
throw new IllegalArgumentException("negative size: " + size);
} else { // index >= size
return format("%s (%s) must be less than size (%s)", desc, index, size);
}
}
/**
* Ensures that {@code index} specifies a valid <i>position</i> in an array,
* list or string of size {@code size}. A position index may range from zero
* to {@code size}, inclusive.
*
* @param index a user-supplied index identifying a position in an array, list
* or string
* @param size the size of that array, list or string
* @return the value of {@code index}
* @throws IndexOutOfBoundsException if {@code index} is negative or is
* greater than {@code size}
* @throws IllegalArgumentException if {@code size} is negative
*/
public static int checkPositionIndex(int index, int size) {
return checkPositionIndex(index, size, "index");
}
/**
* Ensures that {@code index} specifies a valid <i>position</i> in an array,
* list or string of size {@code size}. A position index may range from zero
* to {@code size}, inclusive.
*
* @param index a user-supplied index identifying a position in an array, list
* or string
* @param size the size of that array, list or string
* @param desc the text to use to describe this index in an error message
* @return the value of {@code index}
* @throws IndexOutOfBoundsException if {@code index} is negative or is
* greater than {@code size}
* @throws IllegalArgumentException if {@code size} is negative
*/
public static int checkPositionIndex(
int index, int size, @Nullable String desc) {
// Carefully optimized for execution by hotspot (explanatory comment above)
if (index < 0 || index > size) {
throw new IndexOutOfBoundsException(badPositionIndex(index, size, desc));
}
return index;
}
private static String badPositionIndex(int index, int size, String desc) {
if (index < 0) {
return format("%s (%s) must not be negative", desc, index);
} else if (size < 0) {
throw new IllegalArgumentException("negative size: " + size);
} else { // index > size
return format("%s (%s) must not be greater than size (%s)",
desc, index, size);
}
}
/**
* Ensures that {@code start} and {@code end} specify a valid <i>positions</i>
* in an array, list or string of size {@code size}, and are in order. A
* position index may range from zero to {@code size}, inclusive.
*
* @param start a user-supplied index identifying a starting position in an
* array, list or string
* @param end a user-supplied index identifying a ending position in an array,
* list or string
* @param size the size of that array, list or string
* @throws IndexOutOfBoundsException if either index is negative or is
* greater than {@code size}, or if {@code end} is less than {@code start}
* @throws IllegalArgumentException if {@code size} is negative
*/
public static void checkPositionIndexes(int start, int end, int size) {
// Carefully optimized for execution by hotspot (explanatory comment above)
if (start < 0 || end < start || end > size) {
throw new IndexOutOfBoundsException(badPositionIndexes(start, end, size));
}
}
private static String badPositionIndexes(int start, int end, int size) {
if (start < 0 || start > size) {
return badPositionIndex(start, size, "start index");
}
if (end < 0 || end > size) {
return badPositionIndex(end, size, "end index");
}
// end < start
return format("end index (%s) must not be less than start index (%s)",
end, start);
}
/**
* Substitutes each {@code %s} in {@code template} with an argument. These
* are matched by position - the first {@code %s} gets {@code args[0]}, etc.
* If there are more arguments than placeholders, the unmatched arguments will
* be appended to the end of the formatted message in square braces.
*
* @param template a non-null string containing 0 or more {@code %s}
* placeholders.
* @param args the arguments to be substituted into the message
* template. Arguments are converted to strings using
* {@link String#valueOf(Object)}. Arguments can be null.
*/
@VisibleForTesting static String format(String template,
@Nullable Object... args) {
template = String.valueOf(template); // null -> "null"
// start substituting the arguments into the '%s' placeholders
StringBuilder builder = new StringBuilder(
template.length() + 16 * args.length);
int templateStart = 0;
int i = 0;
while (i < args.length) {
int placeholderStart = template.indexOf("%s", templateStart);
if (placeholderStart == -1) {
break;
}
builder.append(template.substring(templateStart, placeholderStart));
builder.append(args[i++]);
templateStart = placeholderStart + 2;
}
builder.append(template.substring(templateStart));
// if we run out of placeholders, append the extra args in square braces
if (i < args.length) {
builder.append(" [");
builder.append(args[i++]);
while (i < args.length) {
builder.append(", ");
builder.append(args[i++]);
}
builder.append(']');
}
return builder.toString();
}
}
| Java |
/*
* Copyright (C) 2010 The Guava Authors
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package com.google.common.base;
import com.google.common.annotations.Beta;
import com.google.common.annotations.GwtCompatible;
import java.io.Serializable;
/**
* Contains static factory methods for creating {@code Equivalence} instances.
*
* <p>All methods return serializable instances.
*
* @author Bob Lee
* @author Kurt Alfred Kluever
* @author Gregory Kick
* @since 4.0
*/
@Beta
@GwtCompatible
public final class Equivalences {
private Equivalences() {}
/**
* Returns an equivalence that delegates to {@link Object#equals} and {@link Object#hashCode}.
* {@link Equivalence#equivalent} returns {@code true} if both values are null, or if neither
* value is null and {@link Object#equals} returns {@code true}. {@link Equivalence#hash} returns
* {@code 0} if passed a null value.
*
* @since 8.0 (present null-friendly behavior)
* @since 4.0 (otherwise)
*/
public static Equivalence<Object> equals() {
return Equals.INSTANCE;
}
/**
* Returns an equivalence that uses {@code ==} to compare values and {@link
* System#identityHashCode(Object)} to compute the hash code. {@link Equivalence#equivalent}
* returns {@code true} if {@code a == b}, including in the case that a and b are both null.
*/
public static Equivalence<Object> identity() {
return Identity.INSTANCE;
}
private static final class Equals extends Equivalence<Object>
implements Serializable {
static final Equals INSTANCE = new Equals();
@Override protected boolean doEquivalent(Object a, Object b) {
return a.equals(b);
}
@Override public int doHash(Object o) {
return o.hashCode();
}
private Object readResolve() {
return INSTANCE;
}
private static final long serialVersionUID = 1;
}
private static final class Identity extends Equivalence<Object>
implements Serializable {
static final Identity INSTANCE = new Identity();
@Override protected boolean doEquivalent(Object a, Object b) {
return false;
}
@Override protected int doHash(Object o) {
return System.identityHashCode(o);
}
private Object readResolve() {
return INSTANCE;
}
private static final long serialVersionUID = 1;
}
}
| Java |
/*
* Copyright (C) 2007 The Guava Authors
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package com.google.common.base;
import static com.google.common.base.Preconditions.checkNotNull;
import com.google.common.annotations.GwtCompatible;
import java.util.Arrays;
import java.util.LinkedList;
import java.util.List;
import javax.annotation.Nullable;
/**
* Helper functions that can operate on any {@code Object}.
*
* <p>See the Guava User Guide on <a
* href="http://code.google.com/p/guava-libraries/wiki/CommonObjectUtilitiesExplained">writing
* {@code Object} methods with {@code Objects}</a>.
*
* @author Laurence Gonsalves
* @since 2.0 (imported from Google Collections Library)
*/
@GwtCompatible
public final class Objects {
private Objects() {}
/**
* Determines whether two possibly-null objects are equal. Returns:
*
* <ul>
* <li>{@code true} if {@code a} and {@code b} are both null.
* <li>{@code true} if {@code a} and {@code b} are both non-null and they are
* equal according to {@link Object#equals(Object)}.
* <li>{@code false} in all other situations.
* </ul>
*
* <p>This assumes that any non-null objects passed to this function conform
* to the {@code equals()} contract.
*/
public static boolean equal(@Nullable Object a, @Nullable Object b) {
return a == b || (a != null && a.equals(b));
}
/**
* Generates a hash code for multiple values. The hash code is generated by
* calling {@link Arrays#hashCode(Object[])}.
*
* <p>This is useful for implementing {@link Object#hashCode()}. For example,
* in an object that has three properties, {@code x}, {@code y}, and
* {@code z}, one could write:
* <pre>
* public int hashCode() {
* return Objects.hashCode(getX(), getY(), getZ());
* }</pre>
*
* <b>Warning</b>: When a single object is supplied, the returned hash code
* does not equal the hash code of that object.
*/
public static int hashCode(@Nullable Object... objects) {
return Arrays.hashCode(objects);
}
/**
* Creates an instance of {@link ToStringHelper}.
*
* <p>This is helpful for implementing {@link Object#toString()}.
* Specification by example: <pre> {@code
* // Returns "ClassName{}"
* Objects.toStringHelper(this)
* .toString();
*
* // Returns "ClassName{x=1}"
* Objects.toStringHelper(this)
* .add("x", 1)
* .toString();
*
* // Returns "MyObject{x=1}"
* Objects.toStringHelper("MyObject")
* .add("x", 1)
* .toString();
*
* // Returns "ClassName{x=1, y=foo}"
* Objects.toStringHelper(this)
* .add("x", 1)
* .add("y", "foo")
* .toString();
* }}
*
* // Returns "ClassName{x=1}"
* Objects.toStringHelper(this)
* .omitNullValues()
* .add("x", 1)
* .add("y", null)
* .toString();
* }}</pre>
*
* <p>Note that in GWT, class names are often obfuscated.
*
* @param self the object to generate the string for (typically {@code this}),
* used only for its class name
* @since 2.0
*/
public static ToStringHelper toStringHelper(Object self) {
return new ToStringHelper(simpleName(self.getClass()));
}
/**
* Creates an instance of {@link ToStringHelper} in the same manner as
* {@link Objects#toStringHelper(Object)}, but using the name of {@code clazz}
* instead of using an instance's {@link Object#getClass()}.
*
* <p>Note that in GWT, class names are often obfuscated.
*
* @param clazz the {@link Class} of the instance
* @since 7.0 (source-compatible since 2.0)
*/
public static ToStringHelper toStringHelper(Class<?> clazz) {
return new ToStringHelper(simpleName(clazz));
}
/**
* Creates an instance of {@link ToStringHelper} in the same manner as
* {@link Objects#toStringHelper(Object)}, but using {@code className} instead
* of using an instance's {@link Object#getClass()}.
*
* @param className the name of the instance type
* @since 7.0 (source-compatible since 2.0)
*/
public static ToStringHelper toStringHelper(String className) {
return new ToStringHelper(className);
}
/**
* {@link Class#getSimpleName()} is not GWT compatible yet, so we
* provide our own implementation.
*/
private static String simpleName(Class<?> clazz) {
String name = clazz.getName();
// the nth anonymous class has a class name ending in "Outer$n"
// and local inner classes have names ending in "Outer.$1Inner"
name = name.replaceAll("\\$[0-9]+", "\\$");
// we want the name of the inner class all by its lonesome
int start = name.lastIndexOf('$');
// if this isn't an inner class, just find the start of the
// top level class name.
if (start == -1) {
start = name.lastIndexOf('.');
}
return name.substring(start + 1);
}
/**
* Returns the first of two given parameters that is not {@code null}, if
* either is, or otherwise throws a {@link NullPointerException}.
*
* <p><b>Note:</b> if {@code first} is represented as an {@code Optional<T>},
* this can be accomplished with {@code first.or(second)}. That approach also
* allows for lazy evaluation of the fallback instance, using
* {@code first.or(Supplier)}.
*
* @return {@code first} if {@code first} is not {@code null}, or
* {@code second} if {@code first} is {@code null} and {@code second} is
* not {@code null}
* @throws NullPointerException if both {@code first} and {@code second} were
* {@code null}
* @since 3.0
*/
public static <T> T firstNonNull(@Nullable T first, @Nullable T second) {
return first != null ? first : checkNotNull(second);
}
/**
* Support class for {@link Objects#toStringHelper}.
*
* @author Jason Lee
* @since 2.0
*/
public static final class ToStringHelper {
private final String className;
private final List<ValueHolder> valueHolders =
new LinkedList<ValueHolder>();
private boolean omitNullValues = false;
/**
* Use {@link Objects#toStringHelper(Object)} to create an instance.
*/
private ToStringHelper(String className) {
this.className = checkNotNull(className);
}
/**
* When called, the formatted output returned by {@link #toString()} will
* ignore {@code null} values.
*
* @since 12.0
*/
public ToStringHelper omitNullValues() {
omitNullValues = true;
return this;
}
/**
* Adds a name/value pair to the formatted output in {@code name=value}
* format. If {@code value} is {@code null}, the string {@code "null"}
* is used, unless {@link #omitNullValues()} is called, in which case this
* name/value pair will not be added.
*/
public ToStringHelper add(String name, @Nullable Object value) {
checkNotNull(name);
addHolder(value).builder.append(name).append('=').append(value);
return this;
}
/**
* Adds a name/value pair to the formatted output in {@code name=value}
* format.
*
* @since 11.0 (source-compatible since 2.0)
*/
public ToStringHelper add(String name, boolean value) {
checkNameAndAppend(name).append(value);
return this;
}
/**
* Adds a name/value pair to the formatted output in {@code name=value}
* format.
*
* @since 11.0 (source-compatible since 2.0)
*/
public ToStringHelper add(String name, char value) {
checkNameAndAppend(name).append(value);
return this;
}
/**
* Adds a name/value pair to the formatted output in {@code name=value}
* format.
*
* @since 11.0 (source-compatible since 2.0)
*/
public ToStringHelper add(String name, double value) {
checkNameAndAppend(name).append(value);
return this;
}
/**
* Adds a name/value pair to the formatted output in {@code name=value}
* format.
*
* @since 11.0 (source-compatible since 2.0)
*/
public ToStringHelper add(String name, float value) {
checkNameAndAppend(name).append(value);
return this;
}
/**
* Adds a name/value pair to the formatted output in {@code name=value}
* format.
*
* @since 11.0 (source-compatible since 2.0)
*/
public ToStringHelper add(String name, int value) {
checkNameAndAppend(name).append(value);
return this;
}
/**
* Adds a name/value pair to the formatted output in {@code name=value}
* format.
*
* @since 11.0 (source-compatible since 2.0)
*/
public ToStringHelper add(String name, long value) {
checkNameAndAppend(name).append(value);
return this;
}
private StringBuilder checkNameAndAppend(String name) {
checkNotNull(name);
return addHolder().builder.append(name).append('=');
}
/**
* Adds an unnamed value to the formatted output.
*
* <p>It is strongly encouraged to use {@link #add(String, Object)} instead
* and give value a readable name.
*/
public ToStringHelper addValue(@Nullable Object value) {
addHolder(value).builder.append(value);
return this;
}
/**
* Adds an unnamed value to the formatted output.
*
* <p>It is strongly encouraged to use {@link #add(String, boolean)} instead
* and give value a readable name.
*
* @since 11.0 (source-compatible since 2.0)
*/
public ToStringHelper addValue(boolean value) {
addHolder().builder.append(value);
return this;
}
/**
* Adds an unnamed value to the formatted output.
*
* <p>It is strongly encouraged to use {@link #add(String, char)} instead
* and give value a readable name.
*
* @since 11.0 (source-compatible since 2.0)
*/
public ToStringHelper addValue(char value) {
addHolder().builder.append(value);
return this;
}
/**
* Adds an unnamed value to the formatted output.
*
* <p>It is strongly encouraged to use {@link #add(String, double)} instead
* and give value a readable name.
*
* @since 11.0 (source-compatible since 2.0)
*/
public ToStringHelper addValue(double value) {
addHolder().builder.append(value);
return this;
}
/**
* Adds an unnamed value to the formatted output.
*
* <p>It is strongly encouraged to use {@link #add(String, float)} instead
* and give value a readable name.
*
* @since 11.0 (source-compatible since 2.0)
*/
public ToStringHelper addValue(float value) {
addHolder().builder.append(value);
return this;
}
/**
* Adds an unnamed value to the formatted output.
*
* <p>It is strongly encouraged to use {@link #add(String, int)} instead
* and give value a readable name.
*
* @since 11.0 (source-compatible since 2.0)
*/
public ToStringHelper addValue(int value) {
addHolder().builder.append(value);
return this;
}
/**
* Adds an unnamed value to the formatted output.
*
* <p>It is strongly encouraged to use {@link #add(String, long)} instead
* and give value a readable name.
*
* @since 11.0 (source-compatible since 2.0)
*/
public ToStringHelper addValue(long value) {
addHolder().builder.append(value);
return this;
}
/**
* Returns a string in the format specified by {@link
* Objects#toStringHelper(Object)}.
*/
@Override public String toString() {
// create a copy to keep it consistent in case value changes
boolean omitNullValuesSnapshot = omitNullValues;
boolean needsSeparator = false;
StringBuilder builder = new StringBuilder(32).append(className)
.append('{');
for (ValueHolder valueHolder : valueHolders) {
if (!omitNullValuesSnapshot || !valueHolder.isNull) {
if (needsSeparator) {
builder.append(", ");
} else {
needsSeparator = true;
}
// must explicitly cast it, otherwise GWT tests might fail because
// it tries to access StringBuilder.append(StringBuilder), which is
// a private method
// TODO(user): change once 5904010 is fixed
CharSequence sequence = valueHolder.builder;
builder.append(sequence);
}
}
return builder.append('}').toString();
}
private ValueHolder addHolder() {
ValueHolder valueHolder = new ValueHolder();
valueHolders.add(valueHolder);
return valueHolder;
}
private ValueHolder addHolder(@Nullable Object value) {
ValueHolder valueHolder = addHolder();
valueHolder.isNull = (value == null);
return valueHolder;
}
private static final class ValueHolder {
final StringBuilder builder = new StringBuilder();
boolean isNull;
}
}
}
| Java |
/*
* Copyright (C) 2007 The Guava Authors
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package com.google.common.base;
import java.nio.charset.Charset;
/**
* Contains constant definitions for the six standard {@link Charset} instances, which are
* guaranteed to be supported by all Java platform implementations.
*
* <p>See the Guava User Guide article on <a
* href="http://code.google.com/p/guava-libraries/wiki/StringsExplained#Charsets">
* {@code Charsets}</a>.
*
* @author Mike Bostock
* @since 1.0
*/
public final class Charsets {
private Charsets() {}
/**
* US-ASCII: seven-bit ASCII, the Basic Latin block of the Unicode character set (ISO646-US).
*/
public static final Charset US_ASCII = Charset.forName("US-ASCII");
/**
* ISO-8859-1: ISO Latin Alphabet Number 1 (ISO-LATIN-1).
*/
public static final Charset ISO_8859_1 = Charset.forName("ISO-8859-1");
/**
* UTF-8: eight-bit UCS Transformation Format.
*/
public static final Charset UTF_8 = Charset.forName("UTF-8");
/**
* UTF-16BE: sixteen-bit UCS Transformation Format, big-endian byte order.
*/
public static final Charset UTF_16BE = Charset.forName("UTF-16BE");
/**
* UTF-16LE: sixteen-bit UCS Transformation Format, little-endian byte order.
*/
public static final Charset UTF_16LE = Charset.forName("UTF-16LE");
/**
* UTF-16: sixteen-bit UCS Transformation Format, byte order identified by an optional byte-order
* mark.
*/
public static final Charset UTF_16 = Charset.forName("UTF-16");
/*
* Please do not add new Charset references to this class, unless those character encodings are
* part of the set required to be supported by all Java platform implementations! Any Charsets
* initialized here may cause unexpected delays when this class is loaded. See the Charset
* Javadocs for the list of built-in character encodings.
*/
}
| Java |
/*
* Copyright (C) 2011 The Guava Authors
*
* Licensed under the Apache License, Version 2.0 (the "License"); you may not
* use this file except in compliance with the License. You may obtain a copy
* of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
* WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
* License for the specific language governing permissions and limitations under
* the License.
*/
package com.google.common.base;
import static com.google.common.base.Preconditions.checkNotNull;
import com.google.common.annotations.Beta;
import com.google.common.annotations.GwtCompatible;
import java.io.Serializable;
import javax.annotation.Nullable;
/**
* Equivalence applied on functional result.
*
* @author Bob Lee
* @since 10.0
*/
@Beta
@GwtCompatible
final class FunctionalEquivalence<F, T> extends Equivalence<F>
implements Serializable {
private static final long serialVersionUID = 0;
private final Function<F, ? extends T> function;
private final Equivalence<T> resultEquivalence;
FunctionalEquivalence(
Function<F, ? extends T> function, Equivalence<T> resultEquivalence) {
this.function = checkNotNull(function);
this.resultEquivalence = checkNotNull(resultEquivalence);
}
@Override protected boolean doEquivalent(F a, F b) {
return resultEquivalence.equivalent(function.apply(a), function.apply(b));
}
@Override protected int doHash(F a) {
return resultEquivalence.hash(function.apply(a));
}
@Override public boolean equals(@Nullable Object obj) {
if (obj == this) {
return true;
}
if (obj instanceof FunctionalEquivalence) {
FunctionalEquivalence<?, ?> that = (FunctionalEquivalence<?, ?>) obj;
return function.equals(that.function)
&& resultEquivalence.equals(that.resultEquivalence);
}
return false;
}
@Override public int hashCode() {
return Objects.hashCode(function, resultEquivalence);
}
@Override public String toString() {
return resultEquivalence + ".onResultOf(" + function + ")";
}
}
| Java |
/*
* Copyright (C) 2008 The Guava Authors
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package com.google.common.base;
import static com.google.common.base.Preconditions.checkNotNull;
import com.google.common.annotations.Beta;
import com.google.common.annotations.GwtCompatible;
import java.io.IOException;
import java.util.AbstractList;
import java.util.Arrays;
import java.util.Iterator;
import java.util.Map;
import java.util.Map.Entry;
import javax.annotation.CheckReturnValue;
import javax.annotation.Nullable;
/**
* An object which joins pieces of text (specified as an array, {@link Iterable}, varargs or even a
* {@link Map}) with a separator. It either appends the results to an {@link Appendable} or returns
* them as a {@link String}. Example: <pre> {@code
*
* Joiner joiner = Joiner.on("; ").skipNulls();
* . . .
* return joiner.join("Harry", null, "Ron", "Hermione");}</pre>
*
* This returns the string {@code "Harry; Ron; Hermione"}. Note that all input elements are
* converted to strings using {@link Object#toString()} before being appended.
*
* <p>If neither {@link #skipNulls()} nor {@link #useForNull(String)} is specified, the joining
* methods will throw {@link NullPointerException} if any given element is null.
*
* <p><b>Warning: joiner instances are always immutable</b>; a configuration method such as {@code
* useForNull} has no effect on the instance it is invoked on! You must store and use the new joiner
* instance returned by the method. This makes joiners thread-safe, and safe to store as {@code
* static final} constants. <pre> {@code
*
* // Bad! Do not do this!
* Joiner joiner = Joiner.on(',');
* joiner.skipNulls(); // does nothing!
* return joiner.join("wrong", null, "wrong");}</pre>
*
* <p>See the Guava User Guide article on <a href=
* "http://code.google.com/p/guava-libraries/wiki/StringsExplained#Joiner">{@code Joiner}</a>.
*
* @author Kevin Bourrillion
* @since 2.0 (imported from Google Collections Library)
*/
@GwtCompatible
public class Joiner {
/**
* Returns a joiner which automatically places {@code separator} between consecutive elements.
*/
public static Joiner on(String separator) {
return new Joiner(separator);
}
/**
* Returns a joiner which automatically places {@code separator} between consecutive elements.
*/
public static Joiner on(char separator) {
return new Joiner(String.valueOf(separator));
}
private final String separator;
private Joiner(String separator) {
this.separator = checkNotNull(separator);
}
private Joiner(Joiner prototype) {
this.separator = prototype.separator;
}
/**
* <b>Deprecated.</b>
*
* @since 11.0
* @deprecated use {@link #appendTo(Appendable, Iterator)} by casting {@code parts} to
* {@code Iterator<?>}, or better yet, by implementing only {@code Iterator} and not
* {@code Iterable}. <b>This method is scheduled for deletion in June 2013.</b>
*/
@Beta
@Deprecated
public
final <A extends Appendable, I extends Object & Iterable<?> & Iterator<?>> A
appendTo(A appendable, I parts) throws IOException {
return appendTo(appendable, (Iterator<?>) parts);
}
/**
* Appends the string representation of each of {@code parts}, using the previously configured
* separator between each, to {@code appendable}.
*/
public <A extends Appendable> A appendTo(A appendable, Iterable<?> parts) throws IOException {
return appendTo(appendable, parts.iterator());
}
/**
* Appends the string representation of each of {@code parts}, using the previously configured
* separator between each, to {@code appendable}.
*
* @since 11.0
*/
@Beta
public <A extends Appendable> A appendTo(A appendable, Iterator<?> parts) throws IOException {
checkNotNull(appendable);
if (parts.hasNext()) {
appendable.append(toString(parts.next()));
while (parts.hasNext()) {
appendable.append(separator);
appendable.append(toString(parts.next()));
}
}
return appendable;
}
/**
* Appends the string representation of each of {@code parts}, using the previously configured
* separator between each, to {@code appendable}.
*/
public final <A extends Appendable> A appendTo(A appendable, Object[] parts) throws IOException {
return appendTo(appendable, Arrays.asList(parts));
}
/**
* Appends to {@code appendable} the string representation of each of the remaining arguments.
*/
public final <A extends Appendable> A appendTo(
A appendable, @Nullable Object first, @Nullable Object second, Object... rest)
throws IOException {
return appendTo(appendable, iterable(first, second, rest));
}
/**
* <b>Deprecated.</b>
*
* @since 11.0
* @deprecated use {@link #appendTo(StringBuilder, Iterator)} by casting {@code parts} to
* {@code Iterator<?>}, or better yet, by implementing only {@code Iterator} and not
* {@code Iterable}. <b>This method is scheduled for deletion in June 2013.</b>
*/
@Beta
@Deprecated
public
final <I extends Object & Iterable<?> & Iterator<?>> StringBuilder
appendTo(StringBuilder builder, I parts) {
return appendTo(builder, (Iterator<?>) parts);
}
/**
* Appends the string representation of each of {@code parts}, using the previously configured
* separator between each, to {@code builder}. Identical to {@link #appendTo(Appendable,
* Iterable)}, except that it does not throw {@link IOException}.
*/
public final StringBuilder appendTo(StringBuilder builder, Iterable<?> parts) {
return appendTo(builder, parts.iterator());
}
/**
* Appends the string representation of each of {@code parts}, using the previously configured
* separator between each, to {@code builder}. Identical to {@link #appendTo(Appendable,
* Iterable)}, except that it does not throw {@link IOException}.
*
* @since 11.0
*/
@Beta
public final StringBuilder appendTo(StringBuilder builder, Iterator<?> parts) {
try {
appendTo((Appendable) builder, parts);
} catch (IOException impossible) {
throw new AssertionError(impossible);
}
return builder;
}
/**
* Appends the string representation of each of {@code parts}, using the previously configured
* separator between each, to {@code builder}. Identical to {@link #appendTo(Appendable,
* Iterable)}, except that it does not throw {@link IOException}.
*/
public final StringBuilder appendTo(StringBuilder builder, Object[] parts) {
return appendTo(builder, Arrays.asList(parts));
}
/**
* Appends to {@code builder} the string representation of each of the remaining arguments.
* Identical to {@link #appendTo(Appendable, Object, Object, Object...)}, except that it does not
* throw {@link IOException}.
*/
public final StringBuilder appendTo(
StringBuilder builder, @Nullable Object first, @Nullable Object second, Object... rest) {
return appendTo(builder, iterable(first, second, rest));
}
/**
* <b>Deprecated.</b>
*
* @since 11.0
* @deprecated use {@link #join(Iterator)} by casting {@code parts} to
* {@code Iterator<?>}, or better yet, by implementing only {@code Iterator} and not
* {@code Iterable}. <b>This method is scheduled for deletion in June 2013.</b>
*/
@Beta
@Deprecated
public
final <I extends Object & Iterable<?> & Iterator<?>> String join(I parts) {
return join((Iterator<?>) parts);
}
/**
* Returns a string containing the string representation of each of {@code parts}, using the
* previously configured separator between each.
*/
public final String join(Iterable<?> parts) {
return join(parts.iterator());
}
/**
* Returns a string containing the string representation of each of {@code parts}, using the
* previously configured separator between each.
*
* @since 11.0
*/
@Beta
public final String join(Iterator<?> parts) {
return appendTo(new StringBuilder(), parts).toString();
}
/**
* Returns a string containing the string representation of each of {@code parts}, using the
* previously configured separator between each.
*/
public final String join(Object[] parts) {
return join(Arrays.asList(parts));
}
/**
* Returns a string containing the string representation of each argument, using the previously
* configured separator between each.
*/
public final String join(@Nullable Object first, @Nullable Object second, Object... rest) {
return join(iterable(first, second, rest));
}
/**
* Returns a joiner with the same behavior as this one, except automatically substituting {@code
* nullText} for any provided null elements.
*/
@CheckReturnValue
public Joiner useForNull(final String nullText) {
checkNotNull(nullText);
return new Joiner(this) {
@Override CharSequence toString(Object part) {
return (part == null) ? nullText : Joiner.this.toString(part);
}
@Override public Joiner useForNull(String nullText) {
checkNotNull(nullText); // weird: just to satisfy NullPointerTester.
throw new UnsupportedOperationException("already specified useForNull");
}
@Override public Joiner skipNulls() {
throw new UnsupportedOperationException("already specified useForNull");
}
};
}
/**
* Returns a joiner with the same behavior as this joiner, except automatically skipping over any
* provided null elements.
*/
@CheckReturnValue
public Joiner skipNulls() {
return new Joiner(this) {
@Override public <A extends Appendable> A appendTo(A appendable, Iterator<?> parts)
throws IOException {
checkNotNull(appendable, "appendable");
checkNotNull(parts, "parts");
while (parts.hasNext()) {
Object part = parts.next();
if (part != null) {
appendable.append(Joiner.this.toString(part));
break;
}
}
while (parts.hasNext()) {
Object part = parts.next();
if (part != null) {
appendable.append(separator);
appendable.append(Joiner.this.toString(part));
}
}
return appendable;
}
@Override public Joiner useForNull(String nullText) {
checkNotNull(nullText); // weird: just to satisfy NullPointerTester.
throw new UnsupportedOperationException("already specified skipNulls");
}
@Override public MapJoiner withKeyValueSeparator(String kvs) {
checkNotNull(kvs); // weird: just to satisfy NullPointerTester.
throw new UnsupportedOperationException("can't use .skipNulls() with maps");
}
};
}
/**
* Returns a {@code MapJoiner} using the given key-value separator, and the same configuration as
* this {@code Joiner} otherwise.
*/
@CheckReturnValue
public MapJoiner withKeyValueSeparator(String keyValueSeparator) {
return new MapJoiner(this, keyValueSeparator);
}
/**
* An object that joins map entries in the same manner as {@code Joiner} joins iterables and
* arrays. Like {@code Joiner}, it is thread-safe and immutable.
*
* <p>In addition to operating on {@code Map} instances, {@code MapJoiner} can operate on {@code
* Multimap} entries in two distinct modes:
*
* <ul>
* <li>To output a separate entry for each key-value pair, pass {@code multimap.entries()} to a
* {@code MapJoiner} method that accepts entries as input, and receive output of the form
* {@code key1=A&key1=B&key2=C}.
* <li>To output a single entry for each key, pass {@code multimap.asMap()} to a {@code MapJoiner}
* method that accepts a map as input, and receive output of the form {@code
* key1=[A, B]&key2=C}.
* </ul>
*
* @since 2.0 (imported from Google Collections Library)
*/
public final static class MapJoiner {
private final Joiner joiner;
private final String keyValueSeparator;
private MapJoiner(Joiner joiner, String keyValueSeparator) {
this.joiner = joiner; // only "this" is ever passed, so don't checkNotNull
this.keyValueSeparator = checkNotNull(keyValueSeparator);
}
/**
* Appends the string representation of each entry of {@code map}, using the previously
* configured separator and key-value separator, to {@code appendable}.
*/
public <A extends Appendable> A appendTo(A appendable, Map<?, ?> map) throws IOException {
return appendTo(appendable, map.entrySet());
}
/**
* Appends the string representation of each entry of {@code map}, using the previously
* configured separator and key-value separator, to {@code builder}. Identical to {@link
* #appendTo(Appendable, Map)}, except that it does not throw {@link IOException}.
*/
public StringBuilder appendTo(StringBuilder builder, Map<?, ?> map) {
return appendTo(builder, map.entrySet());
}
/**
* Returns a string containing the string representation of each entry of {@code map}, using the
* previously configured separator and key-value separator.
*/
public String join(Map<?, ?> map) {
return join(map.entrySet());
}
/**
* <b>Deprecated.</b>
*
* @since 11.0
* @deprecated use {@link #appendTo(Appendable, Iterator)} by casting {@code entries} to
* {@code Iterator<? extends Entry<?, ?>>}, or better yet, by implementing only
* {@code Iterator} and not {@code Iterable}. <b>This method is scheduled for deletion
* in June 2013.</b>
*/
@Beta
@Deprecated
public
<A extends Appendable,
I extends Object & Iterable<? extends Entry<?, ?>> & Iterator<? extends Entry<?, ?>>>
A appendTo(A appendable, I entries) throws IOException {
Iterator<? extends Entry<?, ?>> iterator = entries;
return appendTo(appendable, iterator);
}
/**
* Appends the string representation of each entry in {@code entries}, using the previously
* configured separator and key-value separator, to {@code appendable}.
*
* @since 10.0
*/
@Beta
public <A extends Appendable> A appendTo(A appendable, Iterable<? extends Entry<?, ?>> entries)
throws IOException {
return appendTo(appendable, entries.iterator());
}
/**
* Appends the string representation of each entry in {@code entries}, using the previously
* configured separator and key-value separator, to {@code appendable}.
*
* @since 11.0
*/
@Beta
public <A extends Appendable> A appendTo(A appendable, Iterator<? extends Entry<?, ?>> parts)
throws IOException {
checkNotNull(appendable);
if (parts.hasNext()) {
Entry<?, ?> entry = parts.next();
appendable.append(joiner.toString(entry.getKey()));
appendable.append(keyValueSeparator);
appendable.append(joiner.toString(entry.getValue()));
while (parts.hasNext()) {
appendable.append(joiner.separator);
Entry<?, ?> e = parts.next();
appendable.append(joiner.toString(e.getKey()));
appendable.append(keyValueSeparator);
appendable.append(joiner.toString(e.getValue()));
}
}
return appendable;
}
/**
* <b>Deprecated.</b>
*
* @since 11.0
* @deprecated use {@link #appendTo(StringBuilder, Iterator)} by casting {@code entries} to
* {@code Iterator<? extends Entry<?, ?>>}, or better yet, by implementing only
* {@code Iterator} and not {@code Iterable}. <b>This method is scheduled for deletion
* in June 2013.</b>
*/
@Beta
@Deprecated
public
<I extends Object & Iterable<? extends Entry<?, ?>> & Iterator<? extends Entry<?, ?>>>
StringBuilder appendTo(StringBuilder builder, I entries) throws IOException {
Iterator<? extends Entry<?, ?>> iterator = entries;
return appendTo(builder, iterator);
}
/**
* Appends the string representation of each entry in {@code entries}, using the previously
* configured separator and key-value separator, to {@code builder}. Identical to {@link
* #appendTo(Appendable, Iterable)}, except that it does not throw {@link IOException}.
*
* @since 10.0
*/
@Beta
public StringBuilder appendTo(StringBuilder builder, Iterable<? extends Entry<?, ?>> entries) {
return appendTo(builder, entries.iterator());
}
/**
* Appends the string representation of each entry in {@code entries}, using the previously
* configured separator and key-value separator, to {@code builder}. Identical to {@link
* #appendTo(Appendable, Iterable)}, except that it does not throw {@link IOException}.
*
* @since 11.0
*/
@Beta
public StringBuilder appendTo(StringBuilder builder, Iterator<? extends Entry<?, ?>> entries) {
try {
appendTo((Appendable) builder, entries);
} catch (IOException impossible) {
throw new AssertionError(impossible);
}
return builder;
}
/**
* <b>Deprecated.</b>
*
* @since 11.0
* @deprecated use {@link #join(Iterator)} by casting {@code entries} to
* {@code Iterator<? extends Entry<?, ?>>}, or better yet, by implementing only
* {@code Iterator} and not {@code Iterable}. <b>This method is scheduled for deletion
* in June 2013.</b>
*/
@Beta
@Deprecated
public
<I extends Object & Iterable<? extends Entry<?, ?>> & Iterator<? extends Entry<?, ?>>>
String join(I entries) throws IOException {
Iterator<? extends Entry<?, ?>> iterator = entries;
return join(iterator);
}
/**
* Returns a string containing the string representation of each entry in {@code entries}, using
* the previously configured separator and key-value separator.
*
* @since 10.0
*/
@Beta
public String join(Iterable<? extends Entry<?, ?>> entries) {
return join(entries.iterator());
}
/**
* Returns a string containing the string representation of each entry in {@code entries}, using
* the previously configured separator and key-value separator.
*
* @since 11.0
*/
@Beta
public String join(Iterator<? extends Entry<?, ?>> entries) {
return appendTo(new StringBuilder(), entries).toString();
}
/**
* Returns a map joiner with the same behavior as this one, except automatically substituting
* {@code nullText} for any provided null keys or values.
*/
@CheckReturnValue
public MapJoiner useForNull(String nullText) {
return new MapJoiner(joiner.useForNull(nullText), keyValueSeparator);
}
}
CharSequence toString(Object part) {
checkNotNull(part); // checkNotNull for GWT (do not optimize).
return (part instanceof CharSequence) ? (CharSequence) part : part.toString();
}
private static Iterable<Object> iterable(
final Object first, final Object second, final Object[] rest) {
checkNotNull(rest);
return new AbstractList<Object>() {
@Override public int size() {
return rest.length + 2;
}
@Override public Object get(int index) {
switch (index) {
case 0:
return first;
case 1:
return second;
default:
return rest[index - 2];
}
}
};
}
}
| Java |
/*
* Copyright (C) 2011 The Guava Authors
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package com.google.common.base;
import com.google.common.annotations.GwtCompatible;
import java.io.Serializable;
import java.util.Iterator;
import javax.annotation.Nullable;
@GwtCompatible(serializable = true)
final class PairwiseEquivalence<T> extends Equivalence<Iterable<T>>
implements Serializable {
final Equivalence<? super T> elementEquivalence;
PairwiseEquivalence(Equivalence<? super T> elementEquivalence) {
this.elementEquivalence = Preconditions.checkNotNull(elementEquivalence);
}
@Override
protected boolean doEquivalent(Iterable<T> iterableA, Iterable<T> iterableB) {
Iterator<T> iteratorA = iterableA.iterator();
Iterator<T> iteratorB = iterableB.iterator();
while (iteratorA.hasNext() && iteratorB.hasNext()) {
if (!elementEquivalence.equivalent(iteratorA.next(), iteratorB.next())) {
return false;
}
}
return !iteratorA.hasNext() && !iteratorB.hasNext();
}
@Override
protected int doHash(Iterable<T> iterable) {
int hash = 78721;
for (T element : iterable) {
hash = hash * 24943 + elementEquivalence.hash(element);
}
return hash;
}
@Override
public boolean equals(@Nullable Object object) {
if (object instanceof PairwiseEquivalence) {
PairwiseEquivalence<?> that = (PairwiseEquivalence<?>) object;
return this.elementEquivalence.equals(that.elementEquivalence);
}
return false;
}
@Override
public int hashCode() {
return elementEquivalence.hashCode() ^ 0x46a3eb07;
}
@Override
public String toString() {
return elementEquivalence + ".pairwise()";
}
private static final long serialVersionUID = 1;
}
| Java |
/*
* Copyright (C) 2007 The Guava Authors
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package com.google.common.base;
import static com.google.common.base.Preconditions.checkState;
import com.google.common.annotations.GwtCompatible;
import java.util.Iterator;
import java.util.NoSuchElementException;
/**
* Note this class is a copy of
* {@link com.google.common.collect.AbstractIterator} (for dependency reasons).
*/
@GwtCompatible
abstract class AbstractIterator<T> implements Iterator<T> {
private State state = State.NOT_READY;
protected AbstractIterator() {}
private enum State {
READY, NOT_READY, DONE, FAILED,
}
private T next;
protected abstract T computeNext();
protected final T endOfData() {
state = State.DONE;
return null;
}
@Override
public final boolean hasNext() {
checkState(state != State.FAILED);
switch (state) {
case DONE:
return false;
case READY:
return true;
default:
}
return tryToComputeNext();
}
private boolean tryToComputeNext() {
state = State.FAILED; // temporary pessimism
next = computeNext();
if (state != State.DONE) {
state = State.READY;
return true;
}
return false;
}
@Override
public final T next() {
if (!hasNext()) {
throw new NoSuchElementException();
}
state = State.NOT_READY;
return next;
}
@Override public final void remove() {
throw new UnsupportedOperationException();
}
}
| Java |
/*
* Copyright (C) 2007 The Guava Authors
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package com.google.common.base;
import com.google.common.annotations.Beta;
import com.google.common.annotations.GwtCompatible;
import com.google.common.annotations.VisibleForTesting;
import java.io.Serializable;
import java.util.concurrent.TimeUnit;
import javax.annotation.Nullable;
/**
* Useful suppliers.
*
* <p>All methods return serializable suppliers as long as they're given
* serializable parameters.
*
* @author Laurence Gonsalves
* @author Harry Heymann
* @since 2.0 (imported from Google Collections Library)
*/
@GwtCompatible
public final class Suppliers {
private Suppliers() {}
/**
* Returns a new supplier which is the composition of the provided function
* and supplier. In other words, the new supplier's value will be computed by
* retrieving the value from {@code supplier}, and then applying
* {@code function} to that value. Note that the resulting supplier will not
* call {@code supplier} or invoke {@code function} until it is called.
*/
public static <F, T> Supplier<T> compose(
Function<? super F, T> function, Supplier<F> supplier) {
Preconditions.checkNotNull(function);
Preconditions.checkNotNull(supplier);
return new SupplierComposition<F, T>(function, supplier);
}
private static class SupplierComposition<F, T>
implements Supplier<T>, Serializable {
final Function<? super F, T> function;
final Supplier<F> supplier;
SupplierComposition(Function<? super F, T> function, Supplier<F> supplier) {
this.function = function;
this.supplier = supplier;
}
@Override
public T get() {
return function.apply(supplier.get());
}
private static final long serialVersionUID = 0;
}
/**
* Returns a supplier which caches the instance retrieved during the first
* call to {@code get()} and returns that value on subsequent calls to
* {@code get()}. See:
* <a href="http://en.wikipedia.org/wiki/Memoization">memoization</a>
*
* <p>The returned supplier is thread-safe. The supplier's serialized form
* does not contain the cached value, which will be recalculated when {@code
* get()} is called on the reserialized instance.
*
* <p>If {@code delegate} is an instance created by an earlier call to {@code
* memoize}, it is returned directly.
*/
public static <T> Supplier<T> memoize(Supplier<T> delegate) {
return (delegate instanceof MemoizingSupplier)
? delegate
: new MemoizingSupplier<T>(Preconditions.checkNotNull(delegate));
}
@VisibleForTesting
static class MemoizingSupplier<T> implements Supplier<T>, Serializable {
final Supplier<T> delegate;
transient volatile boolean initialized;
// "value" does not need to be volatile; visibility piggy-backs
// on volatile read of "initialized".
transient T value;
MemoizingSupplier(Supplier<T> delegate) {
this.delegate = delegate;
}
@Override
public T get() {
// A 2-field variant of Double Checked Locking.
if (!initialized) {
synchronized (this) {
if (!initialized) {
T t = delegate.get();
value = t;
initialized = true;
return t;
}
}
}
return value;
}
private static final long serialVersionUID = 0;
}
/**
* Returns a supplier that caches the instance supplied by the delegate and
* removes the cached value after the specified time has passed. Subsequent
* calls to {@code get()} return the cached value if the expiration time has
* not passed. After the expiration time, a new value is retrieved, cached,
* and returned. See:
* <a href="http://en.wikipedia.org/wiki/Memoization">memoization</a>
*
* <p>The returned supplier is thread-safe. The supplier's serialized form
* does not contain the cached value, which will be recalculated when {@code
* get()} is called on the reserialized instance.
*
* @param duration the length of time after a value is created that it
* should stop being returned by subsequent {@code get()} calls
* @param unit the unit that {@code duration} is expressed in
* @throws IllegalArgumentException if {@code duration} is not positive
* @since 2.0
*/
public static <T> Supplier<T> memoizeWithExpiration(
Supplier<T> delegate, long duration, TimeUnit unit) {
return new ExpiringMemoizingSupplier<T>(delegate, duration, unit);
}
@VisibleForTesting static class ExpiringMemoizingSupplier<T>
implements Supplier<T>, Serializable {
final Supplier<T> delegate;
final long durationNanos;
transient volatile T value;
// The special value 0 means "not yet initialized".
transient volatile long expirationNanos;
ExpiringMemoizingSupplier(
Supplier<T> delegate, long duration, TimeUnit unit) {
this.delegate = Preconditions.checkNotNull(delegate);
this.durationNanos = unit.toNanos(duration);
Preconditions.checkArgument(duration > 0);
}
@Override
public T get() {
// Another variant of Double Checked Locking.
//
// We use two volatile reads. We could reduce this to one by
// putting our fields into a holder class, but (at least on x86)
// the extra memory consumption and indirection are more
// expensive than the extra volatile reads.
long nanos = expirationNanos;
long now = Platform.systemNanoTime();
if (nanos == 0 || now - nanos >= 0) {
synchronized (this) {
if (nanos == expirationNanos) { // recheck for lost race
T t = delegate.get();
value = t;
nanos = now + durationNanos;
// In the very unlikely event that nanos is 0, set it to 1;
// no one will notice 1 ns of tardiness.
expirationNanos = (nanos == 0) ? 1 : nanos;
return t;
}
}
}
return value;
}
private static final long serialVersionUID = 0;
}
/**
* Returns a supplier that always supplies {@code instance}.
*/
public static <T> Supplier<T> ofInstance(@Nullable T instance) {
return new SupplierOfInstance<T>(instance);
}
private static class SupplierOfInstance<T>
implements Supplier<T>, Serializable {
final T instance;
SupplierOfInstance(@Nullable T instance) {
this.instance = instance;
}
@Override
public T get() {
return instance;
}
private static final long serialVersionUID = 0;
}
/**
* Returns a supplier whose {@code get()} method synchronizes on
* {@code delegate} before calling it, making it thread-safe.
*/
public static <T> Supplier<T> synchronizedSupplier(Supplier<T> delegate) {
return new ThreadSafeSupplier<T>(Preconditions.checkNotNull(delegate));
}
private static class ThreadSafeSupplier<T>
implements Supplier<T>, Serializable {
final Supplier<T> delegate;
ThreadSafeSupplier(Supplier<T> delegate) {
this.delegate = delegate;
}
@Override
public T get() {
synchronized (delegate) {
return delegate.get();
}
}
private static final long serialVersionUID = 0;
}
/**
* Returns a function that accepts a supplier and returns the result of
* invoking {@link Supplier#get} on that supplier.
*
* @since 8.0
*/
@Beta
@SuppressWarnings("unchecked") // SupplierFunction works for any T.
public static <T> Function<Supplier<T>, T> supplierFunction() {
return (Function) SupplierFunction.INSTANCE;
}
private enum SupplierFunction implements Function<Supplier<?>, Object> {
INSTANCE;
@Override
public Object apply(Supplier<?> input) {
return input.get();
}
}
}
| Java |
/*
* Copyright (C) 2011 The Guava Authors
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package com.google.common.base;
import static com.google.common.base.Preconditions.checkNotNull;
import com.google.common.annotations.GwtCompatible;
import java.util.Collections;
import java.util.Set;
import javax.annotation.Nullable;
/**
* Implementation of an {@link Optional} containing a reference.
*/
@GwtCompatible
final class Present<T> extends Optional<T> {
private final T reference;
Present(T reference) {
this.reference = reference;
}
@Override public boolean isPresent() {
return true;
}
@Override public T get() {
return reference;
}
@Override public T or(T defaultValue) {
checkNotNull(defaultValue, "use orNull() instead of or(null)");
return reference;
}
@Override public Optional<T> or(Optional<? extends T> secondChoice) {
checkNotNull(secondChoice);
return this;
}
@Override public T or(Supplier<? extends T> supplier) {
checkNotNull(supplier);
return reference;
}
@Override public T orNull() {
return reference;
}
@Override public Set<T> asSet() {
return Collections.singleton(reference);
}
@Override public boolean equals(@Nullable Object object) {
if (object instanceof Present) {
Present<?> other = (Present<?>) object;
return reference.equals(other.reference);
}
return false;
}
@Override public int hashCode() {
return 0x598df91c + reference.hashCode();
}
@Override public String toString() {
return "Optional.of(" + reference + ")";
}
private static final long serialVersionUID = 0;
}
| Java |
/*
* Copyright (C) 2011 The Guava Authors
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package com.google.common.base;
import static com.google.common.base.Preconditions.checkNotNull;
import com.google.common.annotations.GwtCompatible;
import java.util.Collections;
import java.util.Set;
import javax.annotation.Nullable;
/**
* Implementation of an {@link Optional} not containing a reference.
*/
@GwtCompatible
final class Absent extends Optional<Object> {
static final Absent INSTANCE = new Absent();
@Override public boolean isPresent() {
return false;
}
@Override public Object get() {
throw new IllegalStateException("value is absent");
}
@Override public Object or(Object defaultValue) {
return checkNotNull(defaultValue, "use orNull() instead of or(null)");
}
@SuppressWarnings("unchecked") // safe covariant cast
@Override public Optional<Object> or(Optional<?> secondChoice) {
return (Optional) checkNotNull(secondChoice);
}
@Override public Object or(Supplier<?> supplier) {
return checkNotNull(supplier.get(),
"use orNull() instead of a Supplier that returns null");
}
@Override @Nullable public Object orNull() {
return null;
}
@Override public Set<Object> asSet() {
return Collections.emptySet();
}
@Override public boolean equals(@Nullable Object object) {
return object == this;
}
@Override public int hashCode() {
return 0x598df91c;
}
@Override public String toString() {
return "Optional.absent()";
}
private Object readResolve() {
return INSTANCE;
}
private static final long serialVersionUID = 0;
}
| Java |
/*
* Copyright (C) 2008 The Guava Authors
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package com.google.common.base.internal;
import java.lang.ref.PhantomReference;
import java.lang.ref.Reference;
import java.lang.ref.ReferenceQueue;
import java.lang.ref.WeakReference;
import java.lang.reflect.Field;
import java.lang.reflect.Method;
import java.util.logging.Level;
import java.util.logging.Logger;
/**
* Thread that finalizes referents. All references should implement
* {@code com.google.common.base.FinalizableReference}.
*
* <p>While this class is public, we consider it to be *internal* and not part
* of our published API. It is public so we can access it reflectively across
* class loaders in secure environments.
*
* <p>This class can't depend on other Google Collections code. If we were
* to load this class in the same class loader as the rest of
* Google Collections, this thread would keep an indirect strong reference
* to the class loader and prevent it from being garbage collected. This
* poses a problem for environments where you want to throw away the class
* loader. For example, dynamically reloading a web application or unloading
* an OSGi bundle.
*
* <p>{@code com.google.common.base.FinalizableReferenceQueue} loads this class
* in its own class loader. That way, this class doesn't prevent the main
* class loader from getting garbage collected, and this class can detect when
* the main class loader has been garbage collected and stop itself.
*/
public class Finalizer extends Thread {
private static final Logger logger
= Logger.getLogger(Finalizer.class.getName());
/** Name of FinalizableReference.class. */
private static final String FINALIZABLE_REFERENCE
= "com.google.common.base.FinalizableReference";
/**
* Starts the Finalizer thread. FinalizableReferenceQueue calls this method
* reflectively.
*
* @param finalizableReferenceClass FinalizableReference.class
* @param frq reference to instance of FinalizableReferenceQueue that started
* this thread
* @return ReferenceQueue which Finalizer will poll
*/
public static ReferenceQueue<Object> startFinalizer(
Class<?> finalizableReferenceClass, Object frq) {
/*
* We use FinalizableReference.class for two things:
*
* 1) To invoke FinalizableReference.finalizeReferent()
*
* 2) To detect when FinalizableReference's class loader has to be garbage
* collected, at which point, Finalizer can stop running
*/
if (!finalizableReferenceClass.getName().equals(FINALIZABLE_REFERENCE)) {
throw new IllegalArgumentException(
"Expected " + FINALIZABLE_REFERENCE + ".");
}
Finalizer finalizer = new Finalizer(finalizableReferenceClass, frq);
finalizer.start();
return finalizer.queue;
}
private final WeakReference<Class<?>> finalizableReferenceClassReference;
private final PhantomReference<Object> frqReference;
private final ReferenceQueue<Object> queue = new ReferenceQueue<Object>();
private static final Field inheritableThreadLocals
= getInheritableThreadLocalsField();
/** Constructs a new finalizer thread. */
private Finalizer(Class<?> finalizableReferenceClass, Object frq) {
super(Finalizer.class.getName());
this.finalizableReferenceClassReference
= new WeakReference<Class<?>>(finalizableReferenceClass);
// Keep track of the FRQ that started us so we know when to stop.
this.frqReference = new PhantomReference<Object>(frq, queue);
setDaemon(true);
try {
if (inheritableThreadLocals != null) {
inheritableThreadLocals.set(this, null);
}
} catch (Throwable t) {
logger.log(Level.INFO, "Failed to clear thread local values inherited"
+ " by reference finalizer thread.", t);
}
// TODO(fry): Priority?
}
/**
* Loops continuously, pulling references off the queue and cleaning them up.
*/
@SuppressWarnings("InfiniteLoopStatement")
@Override
public void run() {
try {
while (true) {
try {
cleanUp(queue.remove());
} catch (InterruptedException e) { /* ignore */ }
}
} catch (ShutDown shutDown) { /* ignore */ }
}
/**
* Cleans up a single reference. Catches and logs all throwables.
*/
private void cleanUp(Reference<?> reference) throws ShutDown {
Method finalizeReferentMethod = getFinalizeReferentMethod();
do {
/*
* This is for the benefit of phantom references. Weak and soft
* references will have already been cleared by this point.
*/
reference.clear();
if (reference == frqReference) {
/*
* The client no longer has a reference to the
* FinalizableReferenceQueue. We can stop.
*/
throw new ShutDown();
}
try {
finalizeReferentMethod.invoke(reference);
} catch (Throwable t) {
logger.log(Level.SEVERE, "Error cleaning up after reference.", t);
}
/*
* Loop as long as we have references available so as not to waste
* CPU looking up the Method over and over again.
*/
} while ((reference = queue.poll()) != null);
}
/**
* Looks up FinalizableReference.finalizeReferent() method.
*/
private Method getFinalizeReferentMethod() throws ShutDown {
Class<?> finalizableReferenceClass
= finalizableReferenceClassReference.get();
if (finalizableReferenceClass == null) {
/*
* FinalizableReference's class loader was reclaimed. While there's a
* chance that other finalizable references could be enqueued
* subsequently (at which point the class loader would be resurrected
* by virtue of us having a strong reference to it), we should pretty
* much just shut down and make sure we don't keep it alive any longer
* than necessary.
*/
throw new ShutDown();
}
try {
return finalizableReferenceClass.getMethod("finalizeReferent");
} catch (NoSuchMethodException e) {
throw new AssertionError(e);
}
}
public static Field getInheritableThreadLocalsField() {
try {
Field inheritableThreadLocals
= Thread.class.getDeclaredField("inheritableThreadLocals");
inheritableThreadLocals.setAccessible(true);
return inheritableThreadLocals;
} catch (Throwable t) {
logger.log(Level.INFO, "Couldn't access Thread.inheritableThreadLocals."
+ " Reference finalizer threads will inherit thread local"
+ " values.");
return null;
}
}
/** Indicates that it's time to shut down the Finalizer. */
@SuppressWarnings("serial") // Never serialized or thrown out of this class.
private static class ShutDown extends Exception { }
}
| Java |
/*
* Copyright (C) 2007 The Guava Authors
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package com.google.common.base;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.lang.ref.Reference;
import java.lang.ref.ReferenceQueue;
import java.lang.reflect.Method;
import java.net.URL;
import java.net.URLClassLoader;
import java.util.logging.Level;
import java.util.logging.Logger;
/**
* A reference queue with an associated background thread that dequeues references and invokes
* {@link FinalizableReference#finalizeReferent()} on them.
*
* <p>Keep a strong reference to this object until all of the associated referents have been
* finalized. If this object is garbage collected earlier, the backing thread will not invoke {@code
* finalizeReferent()} on the remaining references.
*
* @author Bob Lee
* @since 2.0 (imported from Google Collections Library)
*/
public class FinalizableReferenceQueue {
/*
* The Finalizer thread keeps a phantom reference to this object. When the client (for example, a
* map built by MapMaker) no longer has a strong reference to this object, the garbage collector
* will reclaim it and enqueue the phantom reference. The enqueued reference will trigger the
* Finalizer to stop.
*
* If this library is loaded in the system class loader, FinalizableReferenceQueue can load
* Finalizer directly with no problems.
*
* If this library is loaded in an application class loader, it's important that Finalizer not
* have a strong reference back to the class loader. Otherwise, you could have a graph like this:
*
* Finalizer Thread runs instance of -> Finalizer.class loaded by -> Application class loader
* which loaded -> ReferenceMap.class which has a static -> FinalizableReferenceQueue instance
*
* Even if no other references to classes from the application class loader remain, the Finalizer
* thread keeps an indirect strong reference to the queue in ReferenceMap, which keeps the
* Finalizer running, and as a result, the application class loader can never be reclaimed.
*
* This means that dynamically loaded web applications and OSGi bundles can't be unloaded.
*
* If the library is loaded in an application class loader, we try to break the cycle by loading
* Finalizer in its own independent class loader:
*
* System class loader -> Application class loader -> ReferenceMap -> FinalizableReferenceQueue
* -> etc. -> Decoupled class loader -> Finalizer
*
* Now, Finalizer no longer keeps an indirect strong reference to the static
* FinalizableReferenceQueue field in ReferenceMap. The application class loader can be reclaimed
* at which point the Finalizer thread will stop and its decoupled class loader can also be
* reclaimed.
*
* If any of this fails along the way, we fall back to loading Finalizer directly in the
* application class loader.
*/
private static final Logger logger = Logger.getLogger(FinalizableReferenceQueue.class.getName());
private static final String FINALIZER_CLASS_NAME = "com.google.common.base.internal.Finalizer";
/** Reference to Finalizer.startFinalizer(). */
private static final Method startFinalizer;
static {
Class<?> finalizer = loadFinalizer(
new SystemLoader(), new DecoupledLoader(), new DirectLoader());
startFinalizer = getStartFinalizer(finalizer);
}
/**
* The actual reference queue that our background thread will poll.
*/
final ReferenceQueue<Object> queue;
/**
* Whether or not the background thread started successfully.
*/
final boolean threadStarted;
/**
* Constructs a new queue.
*/
@SuppressWarnings("unchecked")
public FinalizableReferenceQueue() {
// We could start the finalizer lazily, but I'd rather it blow up early.
ReferenceQueue<Object> queue;
boolean threadStarted = false;
try {
queue = (ReferenceQueue<Object>)
startFinalizer.invoke(null, FinalizableReference.class, this);
threadStarted = true;
} catch (IllegalAccessException impossible) {
throw new AssertionError(impossible); // startFinalizer() is public
} catch (Throwable t) {
logger.log(Level.INFO, "Failed to start reference finalizer thread."
+ " Reference cleanup will only occur when new references are created.", t);
queue = new ReferenceQueue<Object>();
}
this.queue = queue;
this.threadStarted = threadStarted;
}
/**
* Repeatedly dequeues references from the queue and invokes {@link
* FinalizableReference#finalizeReferent()} on them until the queue is empty. This method is a
* no-op if the background thread was created successfully.
*/
void cleanUp() {
if (threadStarted) {
return;
}
Reference<?> reference;
while ((reference = queue.poll()) != null) {
/*
* This is for the benefit of phantom references. Weak and soft references will have already
* been cleared by this point.
*/
reference.clear();
try {
((FinalizableReference) reference).finalizeReferent();
} catch (Throwable t) {
logger.log(Level.SEVERE, "Error cleaning up after reference.", t);
}
}
}
/**
* Iterates through the given loaders until it finds one that can load Finalizer.
*
* @return Finalizer.class
*/
private static Class<?> loadFinalizer(FinalizerLoader... loaders) {
for (FinalizerLoader loader : loaders) {
Class<?> finalizer = loader.loadFinalizer();
if (finalizer != null) {
return finalizer;
}
}
throw new AssertionError();
}
/**
* Loads Finalizer.class.
*/
interface FinalizerLoader {
/**
* Returns Finalizer.class or null if this loader shouldn't or can't load it.
*
* @throws SecurityException if we don't have the appropriate privileges
*/
Class<?> loadFinalizer();
}
/**
* Tries to load Finalizer from the system class loader. If Finalizer is in the system class path,
* we needn't create a separate loader.
*/
static class SystemLoader implements FinalizerLoader {
@Override
public Class<?> loadFinalizer() {
ClassLoader systemLoader;
try {
systemLoader = ClassLoader.getSystemClassLoader();
} catch (SecurityException e) {
logger.info("Not allowed to access system class loader.");
return null;
}
if (systemLoader != null) {
try {
return systemLoader.loadClass(FINALIZER_CLASS_NAME);
} catch (ClassNotFoundException e) {
// Ignore. Finalizer is simply in a child class loader.
return null;
}
} else {
return null;
}
}
}
/**
* Try to load Finalizer in its own class loader. If Finalizer's thread had a direct reference to
* our class loader (which could be that of a dynamically loaded web application or OSGi bundle),
* it would prevent our class loader from getting garbage collected.
*/
static class DecoupledLoader implements FinalizerLoader {
private static final String LOADING_ERROR = "Could not load Finalizer in its own class loader."
+ "Loading Finalizer in the current class loader instead. As a result, you will not be able"
+ "to garbage collect this class loader. To support reclaiming this class loader, either"
+ "resolve the underlying issue, or move Google Collections to your system class path.";
@Override
public Class<?> loadFinalizer() {
try {
/*
* We use URLClassLoader because it's the only concrete class loader implementation in the
* JDK. If we used our own ClassLoader subclass, Finalizer would indirectly reference this
* class loader:
*
* Finalizer.class -> CustomClassLoader -> CustomClassLoader.class -> This class loader
*
* System class loader will (and must) be the parent.
*/
ClassLoader finalizerLoader = newLoader(getBaseUrl());
return finalizerLoader.loadClass(FINALIZER_CLASS_NAME);
} catch (Exception e) {
logger.log(Level.WARNING, LOADING_ERROR, e);
return null;
}
}
/**
* Gets URL for base of path containing Finalizer.class.
*/
URL getBaseUrl() throws IOException {
// Find URL pointing to Finalizer.class file.
String finalizerPath = FINALIZER_CLASS_NAME.replace('.', '/') + ".class";
URL finalizerUrl = getClass().getClassLoader().getResource(finalizerPath);
if (finalizerUrl == null) {
throw new FileNotFoundException(finalizerPath);
}
// Find URL pointing to base of class path.
String urlString = finalizerUrl.toString();
if (!urlString.endsWith(finalizerPath)) {
throw new IOException("Unsupported path style: " + urlString);
}
urlString = urlString.substring(0, urlString.length() - finalizerPath.length());
return new URL(finalizerUrl, urlString);
}
/** Creates a class loader with the given base URL as its classpath. */
URLClassLoader newLoader(URL base) {
return new URLClassLoader(new URL[] {base});
}
}
/**
* Loads Finalizer directly using the current class loader. We won't be able to garbage collect
* this class loader, but at least the world doesn't end.
*/
static class DirectLoader implements FinalizerLoader {
@Override
public Class<?> loadFinalizer() {
try {
return Class.forName(FINALIZER_CLASS_NAME);
} catch (ClassNotFoundException e) {
throw new AssertionError(e);
}
}
}
/**
* Looks up Finalizer.startFinalizer().
*/
static Method getStartFinalizer(Class<?> finalizer) {
try {
return finalizer.getMethod("startFinalizer", Class.class, Object.class);
} catch (NoSuchMethodException e) {
throw new AssertionError(e);
}
}
}
| Java |
/*
* Copyright (C) 2011 The Guava Authors
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package com.google.common.base;
import com.google.common.annotations.Beta;
import com.google.common.annotations.GwtCompatible;
/**
* A time source; returns a time value representing the number of nanoseconds
* elapsed since some fixed but arbitrary point in time.
*
* @author Kevin Bourrillion
* @since 10.0
* (<a href="http://code.google.com/p/guava-libraries/wiki/Compatibility"
* >mostly source-compatible</a> since 9.0)
*/
@Beta
@GwtCompatible
public abstract class Ticker {
/**
* Constructor for use by subclasses.
*/
protected Ticker() {}
/**
* Returns the number of nanoseconds elapsed since this ticker's fixed
* point of reference.
*/
public abstract long read();
/**
* A ticker that reads the current time using {@link System#nanoTime}.
*
* @since 10.0
*/
public static Ticker systemTicker() {
return SYSTEM_TICKER;
}
private static final Ticker SYSTEM_TICKER = new Ticker() {
@Override
public long read() {
return Platform.systemNanoTime();
}
};
}
| Java |
/*
* Copyright (C) 2007 The Guava Authors
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package com.google.common.base;
import static com.google.common.base.Preconditions.checkNotNull;
import com.google.common.annotations.Beta;
import java.io.PrintWriter;
import java.io.StringWriter;
import java.util.ArrayList;
import java.util.Collections;
import java.util.List;
import javax.annotation.Nullable;
/**
* Static utility methods pertaining to instances of {@link Throwable}.
*
* <p>See the Guava User Guide entry on <a href=
* "http://code.google.com/p/guava-libraries/wiki/ThrowablesExplained">
* Throwables</a>.
*
* @author Kevin Bourrillion
* @author Ben Yu
* @since 1.0
*/
public final class Throwables {
private Throwables() {}
/**
* Propagates {@code throwable} exactly as-is, if and only if it is an
* instance of {@code declaredType}. Example usage:
* <pre>
* try {
* someMethodThatCouldThrowAnything();
* } catch (IKnowWhatToDoWithThisException e) {
* handle(e);
* } catch (Throwable t) {
* Throwables.propagateIfInstanceOf(t, IOException.class);
* Throwables.propagateIfInstanceOf(t, SQLException.class);
* throw Throwables.propagate(t);
* }
* </pre>
*/
public static <X extends Throwable> void propagateIfInstanceOf(
@Nullable Throwable throwable, Class<X> declaredType) throws X {
// Check for null is needed to avoid frequent JNI calls to isInstance().
if (throwable != null && declaredType.isInstance(throwable)) {
throw declaredType.cast(throwable);
}
}
/**
* Propagates {@code throwable} exactly as-is, if and only if it is an
* instance of {@link RuntimeException} or {@link Error}. Example usage:
* <pre>
* try {
* someMethodThatCouldThrowAnything();
* } catch (IKnowWhatToDoWithThisException e) {
* handle(e);
* } catch (Throwable t) {
* Throwables.propagateIfPossible(t);
* throw new RuntimeException("unexpected", t);
* }
* </pre>
*/
public static void propagateIfPossible(@Nullable Throwable throwable) {
propagateIfInstanceOf(throwable, Error.class);
propagateIfInstanceOf(throwable, RuntimeException.class);
}
/**
* Propagates {@code throwable} exactly as-is, if and only if it is an
* instance of {@link RuntimeException}, {@link Error}, or
* {@code declaredType}. Example usage:
* <pre>
* try {
* someMethodThatCouldThrowAnything();
* } catch (IKnowWhatToDoWithThisException e) {
* handle(e);
* } catch (Throwable t) {
* Throwables.propagateIfPossible(t, OtherException.class);
* throw new RuntimeException("unexpected", t);
* }
* </pre>
*
* @param throwable the Throwable to possibly propagate
* @param declaredType the single checked exception type declared by the
* calling method
*/
public static <X extends Throwable> void propagateIfPossible(
@Nullable Throwable throwable, Class<X> declaredType) throws X {
propagateIfInstanceOf(throwable, declaredType);
propagateIfPossible(throwable);
}
/**
* Propagates {@code throwable} exactly as-is, if and only if it is an
* instance of {@link RuntimeException}, {@link Error}, {@code declaredType1},
* or {@code declaredType2}. In the unlikely case that you have three or more
* declared checked exception types, you can handle them all by invoking these
* methods repeatedly. See usage example in {@link
* #propagateIfPossible(Throwable, Class)}.
*
* @param throwable the Throwable to possibly propagate
* @param declaredType1 any checked exception type declared by the calling
* method
* @param declaredType2 any other checked exception type declared by the
* calling method
*/
public static <X1 extends Throwable, X2 extends Throwable>
void propagateIfPossible(@Nullable Throwable throwable,
Class<X1> declaredType1, Class<X2> declaredType2) throws X1, X2 {
checkNotNull(declaredType2);
propagateIfInstanceOf(throwable, declaredType1);
propagateIfPossible(throwable, declaredType2);
}
/**
* Propagates {@code throwable} as-is if it is an instance of
* {@link RuntimeException} or {@link Error}, or else as a last resort, wraps
* it in a {@code RuntimeException} then propagates.
* <p>
* This method always throws an exception. The {@code RuntimeException} return
* type is only for client code to make Java type system happy in case a
* return value is required by the enclosing method. Example usage:
* <pre>
* T doSomething() {
* try {
* return someMethodThatCouldThrowAnything();
* } catch (IKnowWhatToDoWithThisException e) {
* return handle(e);
* } catch (Throwable t) {
* throw Throwables.propagate(t);
* }
* }
* </pre>
*
* @param throwable the Throwable to propagate
* @return nothing will ever be returned; this return type is only for your
* convenience, as illustrated in the example above
*/
public static RuntimeException propagate(Throwable throwable) {
propagateIfPossible(checkNotNull(throwable));
throw new RuntimeException(throwable);
}
/**
* Returns the innermost cause of {@code throwable}. The first throwable in a
* chain provides context from when the error or exception was initially
* detected. Example usage:
* <pre>
* assertEquals("Unable to assign a customer id",
* Throwables.getRootCause(e).getMessage());
* </pre>
*/
public static Throwable getRootCause(Throwable throwable) {
Throwable cause;
while ((cause = throwable.getCause()) != null) {
throwable = cause;
}
return throwable;
}
/**
* Gets a {@code Throwable} cause chain as a list. The first entry in the
* list will be {@code throwable} followed by its cause hierarchy. Note
* that this is a snapshot of the cause chain and will not reflect
* any subsequent changes to the cause chain.
*
* <p>Here's an example of how it can be used to find specific types
* of exceptions in the cause chain:
*
* <pre>
* Iterables.filter(Throwables.getCausalChain(e), IOException.class));
* </pre>
*
* @param throwable the non-null {@code Throwable} to extract causes from
* @return an unmodifiable list containing the cause chain starting with
* {@code throwable}
*/
@Beta // TODO(kevinb): decide best return type
public static List<Throwable> getCausalChain(Throwable throwable) {
checkNotNull(throwable);
List<Throwable> causes = new ArrayList<Throwable>(4);
while (throwable != null) {
causes.add(throwable);
throwable = throwable.getCause();
}
return Collections.unmodifiableList(causes);
}
/**
* Returns a string containing the result of
* {@link Throwable#toString() toString()}, followed by the full, recursive
* stack trace of {@code throwable}. Note that you probably should not be
* parsing the resulting string; if you need programmatic access to the stack
* frames, you can call {@link Throwable#getStackTrace()}.
*/
public static String getStackTraceAsString(Throwable throwable) {
StringWriter stringWriter = new StringWriter();
throwable.printStackTrace(new PrintWriter(stringWriter));
return stringWriter.toString();
}
}
| Java |
/*
* Copyright (C) 2007 The Guava Authors
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package com.google.common.base;
import java.lang.ref.PhantomReference;
import java.lang.ref.ReferenceQueue;
/**
* Phantom reference with a {@code finalizeReferent()} method which a background thread invokes
* after the garbage collector reclaims the referent. This is a simpler alternative to using a
* {@link ReferenceQueue}.
*
* <p>Unlike a normal phantom reference, this reference will be cleared automatically.
*
* @author Bob Lee
* @since 2.0 (imported from Google Collections Library)
*/
public abstract class FinalizablePhantomReference<T> extends PhantomReference<T>
implements FinalizableReference {
/**
* Constructs a new finalizable phantom reference.
*
* @param referent to phantom reference
* @param queue that should finalize the referent
*/
protected FinalizablePhantomReference(T referent, FinalizableReferenceQueue queue) {
super(referent, queue.queue);
queue.cleanUp();
}
}
| Java |
/*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You under the Apache License, Version 2.0
* (the "License"); you may not use this file except in compliance with
* the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package com.google.common.primitives;
import static com.google.common.base.Preconditions.checkArgument;
import static com.google.common.base.Preconditions.checkNotNull;
import javax.annotation.CheckForNull;
/**
* Static utility methods derived from Android's {@code Integer.java}.
*/
final class AndroidInteger {
/**
* See {@link Ints#tryParse(String)} for the public interface.
*/
@CheckForNull
static Integer tryParse(String string) {
return tryParse(string, 10);
}
/**
* See {@link Ints#tryParse(String, int)} for the public interface.
*/
@CheckForNull
static Integer tryParse(String string, int radix) {
checkNotNull(string);
checkArgument(radix >= Character.MIN_RADIX,
"Invalid radix %s, min radix is %s", radix, Character.MIN_RADIX);
checkArgument(radix <= Character.MAX_RADIX,
"Invalid radix %s, max radix is %s", radix, Character.MAX_RADIX);
int length = string.length(), i = 0;
if (length == 0) {
return null;
}
boolean negative = string.charAt(i) == '-';
if (negative && ++i == length) {
return null;
}
return tryParse(string, i, radix, negative);
}
@CheckForNull
private static Integer tryParse(String string, int offset, int radix,
boolean negative) {
int max = Integer.MIN_VALUE / radix;
int result = 0, length = string.length();
while (offset < length) {
int digit = Character.digit(string.charAt(offset++), radix);
if (digit == -1) {
return null;
}
if (max > result) {
return null;
}
int next = result * radix - digit;
if (next > result) {
return null;
}
result = next;
}
if (!negative) {
result = -result;
if (result < 0) {
return null;
}
}
// For GWT where ints do not overflow
if (result > Integer.MAX_VALUE || result < Integer.MIN_VALUE) {
return null;
}
return result;
}
private AndroidInteger() {}
}
| Java |
/*
* Copyright (C) 2008 The Guava Authors
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package com.google.common.primitives;
import static com.google.common.base.Preconditions.checkArgument;
import static com.google.common.base.Preconditions.checkElementIndex;
import static com.google.common.base.Preconditions.checkNotNull;
import static com.google.common.base.Preconditions.checkPositionIndexes;
import com.google.common.annotations.Beta;
import com.google.common.annotations.GwtCompatible;
import com.google.common.annotations.GwtIncompatible;
import java.io.Serializable;
import java.util.AbstractList;
import java.util.Arrays;
import java.util.Collection;
import java.util.Collections;
import java.util.Comparator;
import java.util.List;
import java.util.RandomAccess;
import javax.annotation.CheckForNull;
/**
* Static utility methods pertaining to {@code int} primitives, that are not
* already found in either {@link Integer} or {@link Arrays}.
*
* <p>See the Guava User Guide article on <a href=
* "http://code.google.com/p/guava-libraries/wiki/PrimitivesExplained">
* primitive utilities</a>.
*
* @author Kevin Bourrillion
* @since 1.0
*/
@GwtCompatible(emulated = true)
public final class Ints {
private Ints() {}
/**
* The number of bytes required to represent a primitive {@code int}
* value.
*/
public static final int BYTES = Integer.SIZE / Byte.SIZE;
/**
* The largest power of two that can be represented as an {@code int}.
*
* @since 10.0
*/
public static final int MAX_POWER_OF_TWO = 1 << (Integer.SIZE - 2);
/**
* Returns a hash code for {@code value}; equal to the result of invoking
* {@code ((Integer) value).hashCode()}.
*
* @param value a primitive {@code int} value
* @return a hash code for the value
*/
public static int hashCode(int value) {
return value;
}
/**
* Returns the {@code int} value that is equal to {@code value}, if possible.
*
* @param value any value in the range of the {@code int} type
* @return the {@code int} value that equals {@code value}
* @throws IllegalArgumentException if {@code value} is greater than {@link
* Integer#MAX_VALUE} or less than {@link Integer#MIN_VALUE}
*/
public static int checkedCast(long value) {
int result = (int) value;
checkArgument(result == value, "Out of range: %s", value);
return result;
}
/**
* Returns the {@code int} nearest in value to {@code value}.
*
* @param value any {@code long} value
* @return the same value cast to {@code int} if it is in the range of the
* {@code int} type, {@link Integer#MAX_VALUE} if it is too large,
* or {@link Integer#MIN_VALUE} if it is too small
*/
public static int saturatedCast(long value) {
if (value > Integer.MAX_VALUE) {
return Integer.MAX_VALUE;
}
if (value < Integer.MIN_VALUE) {
return Integer.MIN_VALUE;
}
return (int) value;
}
/**
* Compares the two specified {@code int} values. The sign of the value
* returned is the same as that of {@code ((Integer) a).compareTo(b)}.
*
* @param a the first {@code int} to compare
* @param b the second {@code int} to compare
* @return a negative value if {@code a} is less than {@code b}; a positive
* value if {@code a} is greater than {@code b}; or zero if they are equal
*/
public static int compare(int a, int b) {
return (a < b) ? -1 : ((a > b) ? 1 : 0);
}
/**
* Returns {@code true} if {@code target} is present as an element anywhere in
* {@code array}.
*
* @param array an array of {@code int} values, possibly empty
* @param target a primitive {@code int} value
* @return {@code true} if {@code array[i] == target} for some value of {@code
* i}
*/
public static boolean contains(int[] array, int target) {
for (int value : array) {
if (value == target) {
return true;
}
}
return false;
}
/**
* Returns the index of the first appearance of the value {@code target} in
* {@code array}.
*
* @param array an array of {@code int} values, possibly empty
* @param target a primitive {@code int} value
* @return the least index {@code i} for which {@code array[i] == target}, or
* {@code -1} if no such index exists.
*/
public static int indexOf(int[] array, int target) {
return indexOf(array, target, 0, array.length);
}
// TODO(kevinb): consider making this public
private static int indexOf(
int[] array, int target, int start, int end) {
for (int i = start; i < end; i++) {
if (array[i] == target) {
return i;
}
}
return -1;
}
/**
* Returns the start position of the first occurrence of the specified {@code
* target} within {@code array}, or {@code -1} if there is no such occurrence.
*
* <p>More formally, returns the lowest index {@code i} such that {@code
* java.util.Arrays.copyOfRange(array, i, i + target.length)} contains exactly
* the same elements as {@code target}.
*
* @param array the array to search for the sequence {@code target}
* @param target the array to search for as a sub-sequence of {@code array}
*/
public static int indexOf(int[] array, int[] target) {
checkNotNull(array, "array");
checkNotNull(target, "target");
if (target.length == 0) {
return 0;
}
outer:
for (int i = 0; i < array.length - target.length + 1; i++) {
for (int j = 0; j < target.length; j++) {
if (array[i + j] != target[j]) {
continue outer;
}
}
return i;
}
return -1;
}
/**
* Returns the index of the last appearance of the value {@code target} in
* {@code array}.
*
* @param array an array of {@code int} values, possibly empty
* @param target a primitive {@code int} value
* @return the greatest index {@code i} for which {@code array[i] == target},
* or {@code -1} if no such index exists.
*/
public static int lastIndexOf(int[] array, int target) {
return lastIndexOf(array, target, 0, array.length);
}
// TODO(kevinb): consider making this public
private static int lastIndexOf(
int[] array, int target, int start, int end) {
for (int i = end - 1; i >= start; i--) {
if (array[i] == target) {
return i;
}
}
return -1;
}
/**
* Returns the least value present in {@code array}.
*
* @param array a <i>nonempty</i> array of {@code int} values
* @return the value present in {@code array} that is less than or equal to
* every other value in the array
* @throws IllegalArgumentException if {@code array} is empty
*/
public static int min(int... array) {
checkArgument(array.length > 0);
int min = array[0];
for (int i = 1; i < array.length; i++) {
if (array[i] < min) {
min = array[i];
}
}
return min;
}
/**
* Returns the greatest value present in {@code array}.
*
* @param array a <i>nonempty</i> array of {@code int} values
* @return the value present in {@code array} that is greater than or equal to
* every other value in the array
* @throws IllegalArgumentException if {@code array} is empty
*/
public static int max(int... array) {
checkArgument(array.length > 0);
int max = array[0];
for (int i = 1; i < array.length; i++) {
if (array[i] > max) {
max = array[i];
}
}
return max;
}
/**
* Returns the values from each provided array combined into a single array.
* For example, {@code concat(new int[] {a, b}, new int[] {}, new
* int[] {c}} returns the array {@code {a, b, c}}.
*
* @param arrays zero or more {@code int} arrays
* @return a single array containing all the values from the source arrays, in
* order
*/
public static int[] concat(int[]... arrays) {
int length = 0;
for (int[] array : arrays) {
length += array.length;
}
int[] result = new int[length];
int pos = 0;
for (int[] array : arrays) {
System.arraycopy(array, 0, result, pos, array.length);
pos += array.length;
}
return result;
}
/**
* Returns a big-endian representation of {@code value} in a 4-element byte
* array; equivalent to {@code ByteBuffer.allocate(4).putInt(value).array()}.
* For example, the input value {@code 0x12131415} would yield the byte array
* {@code {0x12, 0x13, 0x14, 0x15}}.
*
* <p>If you need to convert and concatenate several values (possibly even of
* different types), use a shared {@link java.nio.ByteBuffer} instance, or use
* {@link com.google.common.io.ByteStreams#newDataOutput()} to get a growable
* buffer.
*/
@GwtIncompatible("doesn't work")
public static byte[] toByteArray(int value) {
return new byte[] {
(byte) (value >> 24),
(byte) (value >> 16),
(byte) (value >> 8),
(byte) value};
}
/**
* Returns the {@code int} value whose big-endian representation is stored in
* the first 4 bytes of {@code bytes}; equivalent to {@code
* ByteBuffer.wrap(bytes).getInt()}. For example, the input byte array {@code
* {0x12, 0x13, 0x14, 0x15, 0x33}} would yield the {@code int} value {@code
* 0x12131415}.
*
* <p>Arguably, it's preferable to use {@link java.nio.ByteBuffer}; that
* library exposes much more flexibility at little cost in readability.
*
* @throws IllegalArgumentException if {@code bytes} has fewer than 4 elements
*/
@GwtIncompatible("doesn't work")
public static int fromByteArray(byte[] bytes) {
checkArgument(bytes.length >= BYTES,
"array too small: %s < %s", bytes.length, BYTES);
return fromBytes(bytes[0], bytes[1], bytes[2], bytes[3]);
}
/**
* Returns the {@code int} value whose byte representation is the given 4
* bytes, in big-endian order; equivalent to {@code Ints.fromByteArray(new
* byte[] {b1, b2, b3, b4})}.
*
* @since 7.0
*/
@GwtIncompatible("doesn't work")
public static int fromBytes(byte b1, byte b2, byte b3, byte b4) {
return b1 << 24 | (b2 & 0xFF) << 16 | (b3 & 0xFF) << 8 | (b4 & 0xFF);
}
/**
* Returns an array containing the same values as {@code array}, but
* guaranteed to be of a specified minimum length. If {@code array} already
* has a length of at least {@code minLength}, it is returned directly.
* Otherwise, a new array of size {@code minLength + padding} is returned,
* containing the values of {@code array}, and zeroes in the remaining places.
*
* @param array the source array
* @param minLength the minimum length the returned array must guarantee
* @param padding an extra amount to "grow" the array by if growth is
* necessary
* @throws IllegalArgumentException if {@code minLength} or {@code padding} is
* negative
* @return an array containing the values of {@code array}, with guaranteed
* minimum length {@code minLength}
*/
public static int[] ensureCapacity(
int[] array, int minLength, int padding) {
checkArgument(minLength >= 0, "Invalid minLength: %s", minLength);
checkArgument(padding >= 0, "Invalid padding: %s", padding);
return (array.length < minLength)
? copyOf(array, minLength + padding)
: array;
}
// Arrays.copyOf() requires Java 6
private static int[] copyOf(int[] original, int length) {
int[] copy = new int[length];
System.arraycopy(original, 0, copy, 0, Math.min(original.length, length));
return copy;
}
/**
* Returns a string containing the supplied {@code int} values separated
* by {@code separator}. For example, {@code join("-", 1, 2, 3)} returns
* the string {@code "1-2-3"}.
*
* @param separator the text that should appear between consecutive values in
* the resulting string (but not at the start or end)
* @param array an array of {@code int} values, possibly empty
*/
public static String join(String separator, int... array) {
checkNotNull(separator);
if (array.length == 0) {
return "";
}
// For pre-sizing a builder, just get the right order of magnitude
StringBuilder builder = new StringBuilder(array.length * 5);
builder.append(array[0]);
for (int i = 1; i < array.length; i++) {
builder.append(separator).append(array[i]);
}
return builder.toString();
}
/**
* Returns a comparator that compares two {@code int} arrays
* lexicographically. That is, it compares, using {@link
* #compare(int, int)}), the first pair of values that follow any
* common prefix, or when one array is a prefix of the other, treats the
* shorter array as the lesser. For example, {@code [] < [1] < [1, 2] < [2]}.
*
* <p>The returned comparator is inconsistent with {@link
* Object#equals(Object)} (since arrays support only identity equality), but
* it is consistent with {@link Arrays#equals(int[], int[])}.
*
* @see <a href="http://en.wikipedia.org/wiki/Lexicographical_order">
* Lexicographical order article at Wikipedia</a>
* @since 2.0
*/
public static Comparator<int[]> lexicographicalComparator() {
return LexicographicalComparator.INSTANCE;
}
private enum LexicographicalComparator implements Comparator<int[]> {
INSTANCE;
@Override
public int compare(int[] left, int[] right) {
int minLength = Math.min(left.length, right.length);
for (int i = 0; i < minLength; i++) {
int result = Ints.compare(left[i], right[i]);
if (result != 0) {
return result;
}
}
return left.length - right.length;
}
}
/**
* Copies a collection of {@code Integer} instances into a new array of
* primitive {@code int} values.
*
* <p>Elements are copied from the argument collection as if by {@code
* collection.toArray()}. Calling this method is as thread-safe as calling
* that method.
*
* @param collection a collection of {@code Integer} objects
* @return an array containing the same values as {@code collection}, in the
* same order, converted to primitives
* @throws NullPointerException if {@code collection} or any of its elements
* is null
*/
public static int[] toArray(Collection<Integer> collection) {
if (collection instanceof IntArrayAsList) {
return ((IntArrayAsList) collection).toIntArray();
}
Object[] boxedArray = collection.toArray();
int len = boxedArray.length;
int[] array = new int[len];
for (int i = 0; i < len; i++) {
// checkNotNull for GWT (do not optimize)
array[i] = (Integer) checkNotNull(boxedArray[i]);
}
return array;
}
/**
* Returns a fixed-size list backed by the specified array, similar to {@link
* Arrays#asList(Object[])}. The list supports {@link List#set(int, Object)},
* but any attempt to set a value to {@code null} will result in a {@link
* NullPointerException}.
*
* <p>The returned list maintains the values, but not the identities, of
* {@code Integer} objects written to or read from it. For example, whether
* {@code list.get(0) == list.get(0)} is true for the returned list is
* unspecified.
*
* @param backingArray the array to back the list
* @return a list view of the array
*/
public static List<Integer> asList(int... backingArray) {
if (backingArray.length == 0) {
return Collections.emptyList();
}
return new IntArrayAsList(backingArray);
}
@GwtCompatible
private static class IntArrayAsList extends AbstractList<Integer>
implements RandomAccess, Serializable {
final int[] array;
final int start;
final int end;
IntArrayAsList(int[] array) {
this(array, 0, array.length);
}
IntArrayAsList(int[] array, int start, int end) {
this.array = array;
this.start = start;
this.end = end;
}
@Override public int size() {
return end - start;
}
@Override public boolean isEmpty() {
return false;
}
@Override public Integer get(int index) {
checkElementIndex(index, size());
return array[start + index];
}
@Override public boolean contains(Object target) {
// Overridden to prevent a ton of boxing
return (target instanceof Integer)
&& Ints.indexOf(array, (Integer) target, start, end) != -1;
}
@Override public int indexOf(Object target) {
// Overridden to prevent a ton of boxing
if (target instanceof Integer) {
int i = Ints.indexOf(array, (Integer) target, start, end);
if (i >= 0) {
return i - start;
}
}
return -1;
}
@Override public int lastIndexOf(Object target) {
// Overridden to prevent a ton of boxing
if (target instanceof Integer) {
int i = Ints.lastIndexOf(array, (Integer) target, start, end);
if (i >= 0) {
return i - start;
}
}
return -1;
}
@Override public Integer set(int index, Integer element) {
checkElementIndex(index, size());
int oldValue = array[start + index];
array[start + index] = checkNotNull(element); // checkNotNull for GWT (do not optimize)
return oldValue;
}
@Override public List<Integer> subList(int fromIndex, int toIndex) {
int size = size();
checkPositionIndexes(fromIndex, toIndex, size);
if (fromIndex == toIndex) {
return Collections.emptyList();
}
return new IntArrayAsList(array, start + fromIndex, start + toIndex);
}
@Override public boolean equals(Object object) {
if (object == this) {
return true;
}
if (object instanceof IntArrayAsList) {
IntArrayAsList that = (IntArrayAsList) object;
int size = size();
if (that.size() != size) {
return false;
}
for (int i = 0; i < size; i++) {
if (array[start + i] != that.array[that.start + i]) {
return false;
}
}
return true;
}
return super.equals(object);
}
@Override public int hashCode() {
int result = 1;
for (int i = start; i < end; i++) {
result = 31 * result + Ints.hashCode(array[i]);
}
return result;
}
@Override public String toString() {
StringBuilder builder = new StringBuilder(size() * 5);
builder.append('[').append(array[start]);
for (int i = start + 1; i < end; i++) {
builder.append(", ").append(array[i]);
}
return builder.append(']').toString();
}
int[] toIntArray() {
// Arrays.copyOfRange() requires Java 6
int size = size();
int[] result = new int[size];
System.arraycopy(array, start, result, 0, size);
return result;
}
private static final long serialVersionUID = 0;
}
/**
* Parses the specified string as a signed decimal integer value. The ASCII
* character {@code '-'} (<code>'\u002D'</code>) is recognized as the
* minus sign.
*
* <p>Unlike {@link Integer#parseInt(String)}, this method returns
* {@code null} instead of throwing an exception if parsing fails.
*
* <p>Note that strings prefixed with ASCII {@code '+'} are rejected, even
* under JDK 7, despite the change to {@link Integer#parseInt(String)} for
* that version.
*
* @param string the string representation of an integer value
* @return the integer value represented by {@code string}, or {@code null} if
* {@code string} has a length of zero or cannot be parsed as an integer
* value
* @since 11.0
*/
@Beta
@CheckForNull
@GwtIncompatible("TODO")
public static Integer tryParse(String string) {
return AndroidInteger.tryParse(string, 10);
}
}
| Java |
/*
* Copyright (C) 2008 The Guava Authors
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package com.google.common.primitives;
import static com.google.common.base.Preconditions.checkArgument;
import static com.google.common.base.Preconditions.checkElementIndex;
import static com.google.common.base.Preconditions.checkNotNull;
import static com.google.common.base.Preconditions.checkPositionIndexes;
import com.google.common.annotations.GwtCompatible;
import com.google.common.annotations.GwtIncompatible;
import java.io.Serializable;
import java.util.AbstractList;
import java.util.Arrays;
import java.util.Collection;
import java.util.Collections;
import java.util.Comparator;
import java.util.List;
import java.util.RandomAccess;
/**
* Static utility methods pertaining to {@code char} primitives, that are not
* already found in either {@link Character} or {@link Arrays}.
*
* <p>All the operations in this class treat {@code char} values strictly
* numerically; they are neither Unicode-aware nor locale-dependent.
*
* <p>See the Guava User Guide article on <a href=
* "http://code.google.com/p/guava-libraries/wiki/PrimitivesExplained">
* primitive utilities</a>.
*
* @author Kevin Bourrillion
* @since 1.0
*/
@GwtCompatible(emulated = true)
public final class Chars {
private Chars() {}
/**
* The number of bytes required to represent a primitive {@code char}
* value.
*/
public static final int BYTES = Character.SIZE / Byte.SIZE;
/**
* Returns a hash code for {@code value}; equal to the result of invoking
* {@code ((Character) value).hashCode()}.
*
* @param value a primitive {@code char} value
* @return a hash code for the value
*/
public static int hashCode(char value) {
return value;
}
/**
* Returns the {@code char} value that is equal to {@code value}, if possible.
*
* @param value any value in the range of the {@code char} type
* @return the {@code char} value that equals {@code value}
* @throws IllegalArgumentException if {@code value} is greater than {@link
* Character#MAX_VALUE} or less than {@link Character#MIN_VALUE}
*/
public static char checkedCast(long value) {
char result = (char) value;
checkArgument(result == value, "Out of range: %s", value);
return result;
}
/**
* Returns the {@code char} nearest in value to {@code value}.
*
* @param value any {@code long} value
* @return the same value cast to {@code char} if it is in the range of the
* {@code char} type, {@link Character#MAX_VALUE} if it is too large,
* or {@link Character#MIN_VALUE} if it is too small
*/
public static char saturatedCast(long value) {
if (value > Character.MAX_VALUE) {
return Character.MAX_VALUE;
}
if (value < Character.MIN_VALUE) {
return Character.MIN_VALUE;
}
return (char) value;
}
/**
* Compares the two specified {@code char} values. The sign of the value
* returned is the same as that of {@code ((Character) a).compareTo(b)}.
*
* @param a the first {@code char} to compare
* @param b the second {@code char} to compare
* @return a negative value if {@code a} is less than {@code b}; a positive
* value if {@code a} is greater than {@code b}; or zero if they are equal
*/
public static int compare(char a, char b) {
return a - b; // safe due to restricted range
}
/**
* Returns {@code true} if {@code target} is present as an element anywhere in
* {@code array}.
*
* @param array an array of {@code char} values, possibly empty
* @param target a primitive {@code char} value
* @return {@code true} if {@code array[i] == target} for some value of {@code
* i}
*/
public static boolean contains(char[] array, char target) {
for (char value : array) {
if (value == target) {
return true;
}
}
return false;
}
/**
* Returns the index of the first appearance of the value {@code target} in
* {@code array}.
*
* @param array an array of {@code char} values, possibly empty
* @param target a primitive {@code char} value
* @return the least index {@code i} for which {@code array[i] == target}, or
* {@code -1} if no such index exists.
*/
public static int indexOf(char[] array, char target) {
return indexOf(array, target, 0, array.length);
}
// TODO(kevinb): consider making this public
private static int indexOf(
char[] array, char target, int start, int end) {
for (int i = start; i < end; i++) {
if (array[i] == target) {
return i;
}
}
return -1;
}
/**
* Returns the start position of the first occurrence of the specified {@code
* target} within {@code array}, or {@code -1} if there is no such occurrence.
*
* <p>More formally, returns the lowest index {@code i} such that {@code
* java.util.Arrays.copyOfRange(array, i, i + target.length)} contains exactly
* the same elements as {@code target}.
*
* @param array the array to search for the sequence {@code target}
* @param target the array to search for as a sub-sequence of {@code array}
*/
public static int indexOf(char[] array, char[] target) {
checkNotNull(array, "array");
checkNotNull(target, "target");
if (target.length == 0) {
return 0;
}
outer:
for (int i = 0; i < array.length - target.length + 1; i++) {
for (int j = 0; j < target.length; j++) {
if (array[i + j] != target[j]) {
continue outer;
}
}
return i;
}
return -1;
}
/**
* Returns the index of the last appearance of the value {@code target} in
* {@code array}.
*
* @param array an array of {@code char} values, possibly empty
* @param target a primitive {@code char} value
* @return the greatest index {@code i} for which {@code array[i] == target},
* or {@code -1} if no such index exists.
*/
public static int lastIndexOf(char[] array, char target) {
return lastIndexOf(array, target, 0, array.length);
}
// TODO(kevinb): consider making this public
private static int lastIndexOf(
char[] array, char target, int start, int end) {
for (int i = end - 1; i >= start; i--) {
if (array[i] == target) {
return i;
}
}
return -1;
}
/**
* Returns the least value present in {@code array}.
*
* @param array a <i>nonempty</i> array of {@code char} values
* @return the value present in {@code array} that is less than or equal to
* every other value in the array
* @throws IllegalArgumentException if {@code array} is empty
*/
public static char min(char... array) {
checkArgument(array.length > 0);
char min = array[0];
for (int i = 1; i < array.length; i++) {
if (array[i] < min) {
min = array[i];
}
}
return min;
}
/**
* Returns the greatest value present in {@code array}.
*
* @param array a <i>nonempty</i> array of {@code char} values
* @return the value present in {@code array} that is greater than or equal to
* every other value in the array
* @throws IllegalArgumentException if {@code array} is empty
*/
public static char max(char... array) {
checkArgument(array.length > 0);
char max = array[0];
for (int i = 1; i < array.length; i++) {
if (array[i] > max) {
max = array[i];
}
}
return max;
}
/**
* Returns the values from each provided array combined into a single array.
* For example, {@code concat(new char[] {a, b}, new char[] {}, new
* char[] {c}} returns the array {@code {a, b, c}}.
*
* @param arrays zero or more {@code char} arrays
* @return a single array containing all the values from the source arrays, in
* order
*/
public static char[] concat(char[]... arrays) {
int length = 0;
for (char[] array : arrays) {
length += array.length;
}
char[] result = new char[length];
int pos = 0;
for (char[] array : arrays) {
System.arraycopy(array, 0, result, pos, array.length);
pos += array.length;
}
return result;
}
/**
* Returns a big-endian representation of {@code value} in a 2-element byte
* array; equivalent to {@code
* ByteBuffer.allocate(2).putChar(value).array()}. For example, the input
* value {@code '\\u5432'} would yield the byte array {@code {0x54, 0x32}}.
*
* <p>If you need to convert and concatenate several values (possibly even of
* different types), use a shared {@link java.nio.ByteBuffer} instance, or use
* {@link com.google.common.io.ByteStreams#newDataOutput()} to get a growable
* buffer.
*/
@GwtIncompatible("doesn't work")
public static byte[] toByteArray(char value) {
return new byte[] {
(byte) (value >> 8),
(byte) value};
}
/**
* Returns the {@code char} value whose big-endian representation is
* stored in the first 2 bytes of {@code bytes}; equivalent to {@code
* ByteBuffer.wrap(bytes).getChar()}. For example, the input byte array
* {@code {0x54, 0x32}} would yield the {@code char} value {@code '\\u5432'}.
*
* <p>Arguably, it's preferable to use {@link java.nio.ByteBuffer}; that
* library exposes much more flexibility at little cost in readability.
*
* @throws IllegalArgumentException if {@code bytes} has fewer than 2
* elements
*/
@GwtIncompatible("doesn't work")
public static char fromByteArray(byte[] bytes) {
checkArgument(bytes.length >= BYTES,
"array too small: %s < %s", bytes.length, BYTES);
return fromBytes(bytes[0], bytes[1]);
}
/**
* Returns the {@code char} value whose byte representation is the given 2
* bytes, in big-endian order; equivalent to {@code Chars.fromByteArray(new
* byte[] {b1, b2})}.
*
* @since 7.0
*/
@GwtIncompatible("doesn't work")
public static char fromBytes(byte b1, byte b2) {
return (char) ((b1 << 8) | (b2 & 0xFF));
}
/**
* Returns an array containing the same values as {@code array}, but
* guaranteed to be of a specified minimum length. If {@code array} already
* has a length of at least {@code minLength}, it is returned directly.
* Otherwise, a new array of size {@code minLength + padding} is returned,
* containing the values of {@code array}, and zeroes in the remaining places.
*
* @param array the source array
* @param minLength the minimum length the returned array must guarantee
* @param padding an extra amount to "grow" the array by if growth is
* necessary
* @throws IllegalArgumentException if {@code minLength} or {@code padding} is
* negative
* @return an array containing the values of {@code array}, with guaranteed
* minimum length {@code minLength}
*/
public static char[] ensureCapacity(
char[] array, int minLength, int padding) {
checkArgument(minLength >= 0, "Invalid minLength: %s", minLength);
checkArgument(padding >= 0, "Invalid padding: %s", padding);
return (array.length < minLength)
? copyOf(array, minLength + padding)
: array;
}
// Arrays.copyOf() requires Java 6
private static char[] copyOf(char[] original, int length) {
char[] copy = new char[length];
System.arraycopy(original, 0, copy, 0, Math.min(original.length, length));
return copy;
}
/**
* Returns a string containing the supplied {@code char} values separated
* by {@code separator}. For example, {@code join("-", '1', '2', '3')} returns
* the string {@code "1-2-3"}.
*
* @param separator the text that should appear between consecutive values in
* the resulting string (but not at the start or end)
* @param array an array of {@code char} values, possibly empty
*/
public static String join(String separator, char... array) {
checkNotNull(separator);
int len = array.length;
if (len == 0) {
return "";
}
StringBuilder builder
= new StringBuilder(len + separator.length() * (len - 1));
builder.append(array[0]);
for (int i = 1; i < len; i++) {
builder.append(separator).append(array[i]);
}
return builder.toString();
}
/**
* Returns a comparator that compares two {@code char} arrays
* lexicographically. That is, it compares, using {@link
* #compare(char, char)}), the first pair of values that follow any
* common prefix, or when one array is a prefix of the other, treats the
* shorter array as the lesser. For example,
* {@code [] < ['a'] < ['a', 'b'] < ['b']}.
*
* <p>The returned comparator is inconsistent with {@link
* Object#equals(Object)} (since arrays support only identity equality), but
* it is consistent with {@link Arrays#equals(char[], char[])}.
*
* @see <a href="http://en.wikipedia.org/wiki/Lexicographical_order">
* Lexicographical order article at Wikipedia</a>
* @since 2.0
*/
public static Comparator<char[]> lexicographicalComparator() {
return LexicographicalComparator.INSTANCE;
}
private enum LexicographicalComparator implements Comparator<char[]> {
INSTANCE;
@Override
public int compare(char[] left, char[] right) {
int minLength = Math.min(left.length, right.length);
for (int i = 0; i < minLength; i++) {
int result = Chars.compare(left[i], right[i]);
if (result != 0) {
return result;
}
}
return left.length - right.length;
}
}
/**
* Copies a collection of {@code Character} instances into a new array of
* primitive {@code char} values.
*
* <p>Elements are copied from the argument collection as if by {@code
* collection.toArray()}. Calling this method is as thread-safe as calling
* that method.
*
* @param collection a collection of {@code Character} objects
* @return an array containing the same values as {@code collection}, in the
* same order, converted to primitives
* @throws NullPointerException if {@code collection} or any of its elements
* is null
*/
public static char[] toArray(Collection<Character> collection) {
if (collection instanceof CharArrayAsList) {
return ((CharArrayAsList) collection).toCharArray();
}
Object[] boxedArray = collection.toArray();
int len = boxedArray.length;
char[] array = new char[len];
for (int i = 0; i < len; i++) {
// checkNotNull for GWT (do not optimize)
array[i] = (Character) checkNotNull(boxedArray[i]);
}
return array;
}
/**
* Returns a fixed-size list backed by the specified array, similar to {@link
* Arrays#asList(Object[])}. The list supports {@link List#set(int, Object)},
* but any attempt to set a value to {@code null} will result in a {@link
* NullPointerException}.
*
* <p>The returned list maintains the values, but not the identities, of
* {@code Character} objects written to or read from it. For example, whether
* {@code list.get(0) == list.get(0)} is true for the returned list is
* unspecified.
*
* @param backingArray the array to back the list
* @return a list view of the array
*/
public static List<Character> asList(char... backingArray) {
if (backingArray.length == 0) {
return Collections.emptyList();
}
return new CharArrayAsList(backingArray);
}
@GwtCompatible
private static class CharArrayAsList extends AbstractList<Character>
implements RandomAccess, Serializable {
final char[] array;
final int start;
final int end;
CharArrayAsList(char[] array) {
this(array, 0, array.length);
}
CharArrayAsList(char[] array, int start, int end) {
this.array = array;
this.start = start;
this.end = end;
}
@Override public int size() {
return end - start;
}
@Override public boolean isEmpty() {
return false;
}
@Override public Character get(int index) {
checkElementIndex(index, size());
return array[start + index];
}
@Override public boolean contains(Object target) {
// Overridden to prevent a ton of boxing
return (target instanceof Character)
&& Chars.indexOf(array, (Character) target, start, end) != -1;
}
@Override public int indexOf(Object target) {
// Overridden to prevent a ton of boxing
if (target instanceof Character) {
int i = Chars.indexOf(array, (Character) target, start, end);
if (i >= 0) {
return i - start;
}
}
return -1;
}
@Override public int lastIndexOf(Object target) {
// Overridden to prevent a ton of boxing
if (target instanceof Character) {
int i = Chars.lastIndexOf(array, (Character) target, start, end);
if (i >= 0) {
return i - start;
}
}
return -1;
}
@Override public Character set(int index, Character element) {
checkElementIndex(index, size());
char oldValue = array[start + index];
array[start + index] = checkNotNull(element); // checkNotNull for GWT (do not optimize)
return oldValue;
}
@Override public List<Character> subList(int fromIndex, int toIndex) {
int size = size();
checkPositionIndexes(fromIndex, toIndex, size);
if (fromIndex == toIndex) {
return Collections.emptyList();
}
return new CharArrayAsList(array, start + fromIndex, start + toIndex);
}
@Override public boolean equals(Object object) {
if (object == this) {
return true;
}
if (object instanceof CharArrayAsList) {
CharArrayAsList that = (CharArrayAsList) object;
int size = size();
if (that.size() != size) {
return false;
}
for (int i = 0; i < size; i++) {
if (array[start + i] != that.array[that.start + i]) {
return false;
}
}
return true;
}
return super.equals(object);
}
@Override public int hashCode() {
int result = 1;
for (int i = start; i < end; i++) {
result = 31 * result + Chars.hashCode(array[i]);
}
return result;
}
@Override public String toString() {
StringBuilder builder = new StringBuilder(size() * 3);
builder.append('[').append(array[start]);
for (int i = start + 1; i < end; i++) {
builder.append(", ").append(array[i]);
}
return builder.append(']').toString();
}
char[] toCharArray() {
// Arrays.copyOfRange() requires Java 6
int size = size();
char[] result = new char[size];
System.arraycopy(array, start, result, 0, size);
return result;
}
private static final long serialVersionUID = 0;
}
}
| Java |
/*
* Copyright (C) 2009 The Guava Authors
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package com.google.common.primitives;
import static com.google.common.base.Preconditions.checkArgument;
import static com.google.common.base.Preconditions.checkNotNull;
import com.google.common.annotations.VisibleForTesting;
import sun.misc.Unsafe;
import java.lang.reflect.Field;
import java.nio.ByteOrder;
import java.security.AccessController;
import java.security.PrivilegedAction;
import java.util.Comparator;
/**
* Static utility methods pertaining to {@code byte} primitives that interpret
* values as <i>unsigned</i> (that is, any negative value {@code b} is treated
* as the positive value {@code 256 + b}). The corresponding methods that treat
* the values as signed are found in {@link SignedBytes}, and the methods for
* which signedness is not an issue are in {@link Bytes}.
*
* <p>See the Guava User Guide article on <a href=
* "http://code.google.com/p/guava-libraries/wiki/PrimitivesExplained">
* primitive utilities</a>.
*
* @author Kevin Bourrillion
* @author Martin Buchholz
* @author Hiroshi Yamauchi
* @since 1.0
*/
public final class UnsignedBytes {
private UnsignedBytes() {}
/**
* The largest power of two that can be represented as an unsigned {@code byte}.
*
* @since 10.0
*/
public static final byte MAX_POWER_OF_TWO = (byte) (1 << 7);
/**
* Returns the value of the given byte as an integer, when treated as
* unsigned. That is, returns {@code value + 256} if {@code value} is
* negative; {@code value} itself otherwise.
*
* @since 6.0
*/
public static int toInt(byte value) {
return value & 0xFF;
}
/**
* Returns the {@code byte} value that, when treated as unsigned, is equal to
* {@code value}, if possible.
*
* @param value a value between 0 and 255 inclusive
* @return the {@code byte} value that, when treated as unsigned, equals
* {@code value}
* @throws IllegalArgumentException if {@code value} is negative or greater
* than 255
*/
public static byte checkedCast(long value) {
checkArgument(value >> 8 == 0, "out of range: %s", value);
return (byte) value;
}
/**
* Returns the {@code byte} value that, when treated as unsigned, is nearest
* in value to {@code value}.
*
* @param value any {@code long} value
* @return {@code (byte) 255} if {@code value >= 255}, {@code (byte) 0} if
* {@code value <= 0}, and {@code value} cast to {@code byte} otherwise
*/
public static byte saturatedCast(long value) {
if (value > 255) {
return (byte) 255; // -1
}
if (value < 0) {
return (byte) 0;
}
return (byte) value;
}
/**
* Compares the two specified {@code byte} values, treating them as unsigned
* values between 0 and 255 inclusive. For example, {@code (byte) -127} is
* considered greater than {@code (byte) 127} because it is seen as having
* the value of positive {@code 129}.
*
* @param a the first {@code byte} to compare
* @param b the second {@code byte} to compare
* @return a negative value if {@code a} is less than {@code b}; a positive
* value if {@code a} is greater than {@code b}; or zero if they are equal
*/
public static int compare(byte a, byte b) {
return toInt(a) - toInt(b);
}
/**
* Returns the least value present in {@code array}.
*
* @param array a <i>nonempty</i> array of {@code byte} values
* @return the value present in {@code array} that is less than or equal to
* every other value in the array
* @throws IllegalArgumentException if {@code array} is empty
*/
public static byte min(byte... array) {
checkArgument(array.length > 0);
int min = toInt(array[0]);
for (int i = 1; i < array.length; i++) {
int next = toInt(array[i]);
if (next < min) {
min = next;
}
}
return (byte) min;
}
/**
* Returns the greatest value present in {@code array}.
*
* @param array a <i>nonempty</i> array of {@code byte} values
* @return the value present in {@code array} that is greater than or equal
* to every other value in the array
* @throws IllegalArgumentException if {@code array} is empty
*/
public static byte max(byte... array) {
checkArgument(array.length > 0);
int max = toInt(array[0]);
for (int i = 1; i < array.length; i++) {
int next = toInt(array[i]);
if (next > max) {
max = next;
}
}
return (byte) max;
}
/**
* Returns a string containing the supplied {@code byte} values separated by
* {@code separator}. For example, {@code join(":", (byte) 1, (byte) 2,
* (byte) 255)} returns the string {@code "1:2:255"}.
*
* @param separator the text that should appear between consecutive values in
* the resulting string (but not at the start or end)
* @param array an array of {@code byte} values, possibly empty
*/
public static String join(String separator, byte... array) {
checkNotNull(separator);
if (array.length == 0) {
return "";
}
// For pre-sizing a builder, just get the right order of magnitude
StringBuilder builder = new StringBuilder(array.length * 5);
builder.append(toInt(array[0]));
for (int i = 1; i < array.length; i++) {
builder.append(separator).append(toInt(array[i]));
}
return builder.toString();
}
/**
* Returns a comparator that compares two {@code byte} arrays
* lexicographically. That is, it compares, using {@link
* #compare(byte, byte)}), the first pair of values that follow any common
* prefix, or when one array is a prefix of the other, treats the shorter
* array as the lesser. For example, {@code [] < [0x01] < [0x01, 0x7F] <
* [0x01, 0x80] < [0x02]}. Values are treated as unsigned.
*
* <p>The returned comparator is inconsistent with {@link
* Object#equals(Object)} (since arrays support only identity equality), but
* it is consistent with {@link java.util.Arrays#equals(byte[], byte[])}.
*
* @see <a href="http://en.wikipedia.org/wiki/Lexicographical_order">
* Lexicographical order article at Wikipedia</a>
* @since 2.0
*/
public static Comparator<byte[]> lexicographicalComparator() {
return LexicographicalComparatorHolder.BEST_COMPARATOR;
}
@VisibleForTesting
static Comparator<byte[]> lexicographicalComparatorJavaImpl() {
return LexicographicalComparatorHolder.PureJavaComparator.INSTANCE;
}
/**
* Provides a lexicographical comparator implementation; either a Java
* implementation or a faster implementation based on {@link Unsafe}.
*
* <p>Uses reflection to gracefully fall back to the Java implementation if
* {@code Unsafe} isn't available.
*/
@VisibleForTesting
static class LexicographicalComparatorHolder {
static final String UNSAFE_COMPARATOR_NAME =
LexicographicalComparatorHolder.class.getName() + "$UnsafeComparator";
static final Comparator<byte[]> BEST_COMPARATOR = getBestComparator();
@VisibleForTesting
enum UnsafeComparator implements Comparator<byte[]> {
INSTANCE;
static final boolean littleEndian =
ByteOrder.nativeOrder().equals(ByteOrder.LITTLE_ENDIAN);
/*
* The following static final fields exist for performance reasons.
*
* In UnsignedBytesBenchmark, accessing the following objects via static
* final fields is the fastest (more than twice as fast as the Java
* implementation, vs ~1.5x with non-final static fields, on x86_32)
* under the Hotspot server compiler. The reason is obviously that the
* non-final fields need to be reloaded inside the loop.
*
* And, no, defining (final or not) local variables out of the loop still
* isn't as good because the null check on the theUnsafe object remains
* inside the loop and BYTE_ARRAY_BASE_OFFSET doesn't get
* constant-folded.
*
* The compiler can treat static final fields as compile-time constants
* and can constant-fold them while (final or not) local variables are
* run time values.
*/
static final Unsafe theUnsafe;
/** The offset to the first element in a byte array. */
static final int BYTE_ARRAY_BASE_OFFSET;
static {
theUnsafe = (Unsafe) AccessController.doPrivileged(
new PrivilegedAction<Object>() {
@Override
public Object run() {
try {
Field f = Unsafe.class.getDeclaredField("theUnsafe");
f.setAccessible(true);
return f.get(null);
} catch (NoSuchFieldException e) {
// It doesn't matter what we throw;
// it's swallowed in getBestComparator().
throw new Error();
} catch (IllegalAccessException e) {
throw new Error();
}
}
});
BYTE_ARRAY_BASE_OFFSET = theUnsafe.arrayBaseOffset(byte[].class);
// sanity check - this should never fail
if (theUnsafe.arrayIndexScale(byte[].class) != 1) {
throw new AssertionError();
}
}
@Override public int compare(byte[] left, byte[] right) {
int minLength = Math.min(left.length, right.length);
int minWords = minLength / Longs.BYTES;
/*
* Compare 8 bytes at a time. Benchmarking shows comparing 8 bytes at a
* time is no slower than comparing 4 bytes at a time even on 32-bit.
* On the other hand, it is substantially faster on 64-bit.
*/
for (int i = 0; i < minWords * Longs.BYTES; i += Longs.BYTES) {
long lw = theUnsafe.getLong(left, BYTE_ARRAY_BASE_OFFSET + (long) i);
long rw = theUnsafe.getLong(right, BYTE_ARRAY_BASE_OFFSET + (long) i);
long diff = lw ^ rw;
if (diff != 0) {
if (!littleEndian) {
return UnsignedLongs.compare(lw, rw);
}
// Use binary search
int n = 0;
int y;
int x = (int) diff;
if (x == 0) {
x = (int) (diff >>> 32);
n = 32;
}
y = x << 16;
if (y == 0) {
n += 16;
} else {
x = y;
}
y = x << 8;
if (y == 0) {
n += 8;
}
return (int) (((lw >>> n) & 0xFFL) - ((rw >>> n) & 0xFFL));
}
}
// The epilogue to cover the last (minLength % 8) elements.
for (int i = minWords * Longs.BYTES; i < minLength; i++) {
int result = UnsignedBytes.compare(left[i], right[i]);
if (result != 0) {
return result;
}
}
return left.length - right.length;
}
}
enum PureJavaComparator implements Comparator<byte[]> {
INSTANCE;
@Override public int compare(byte[] left, byte[] right) {
int minLength = Math.min(left.length, right.length);
for (int i = 0; i < minLength; i++) {
int result = UnsignedBytes.compare(left[i], right[i]);
if (result != 0) {
return result;
}
}
return left.length - right.length;
}
}
/**
* Returns the Unsafe-using Comparator, or falls back to the pure-Java
* implementation if unable to do so.
*/
static Comparator<byte[]> getBestComparator() {
try {
Class<?> theClass = Class.forName(UNSAFE_COMPARATOR_NAME);
// yes, UnsafeComparator does implement Comparator<byte[]>
@SuppressWarnings("unchecked")
Comparator<byte[]> comparator =
(Comparator<byte[]>) theClass.getEnumConstants()[0];
return comparator;
} catch (Throwable t) { // ensure we really catch *everything*
return lexicographicalComparatorJavaImpl();
}
}
}
}
| Java |
/*
* Copyright (C) 2008 The Guava Authors
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package com.google.common.primitives;
import static com.google.common.base.Preconditions.checkArgument;
import static com.google.common.base.Preconditions.checkElementIndex;
import static com.google.common.base.Preconditions.checkNotNull;
import static com.google.common.base.Preconditions.checkPositionIndexes;
import com.google.common.annotations.GwtCompatible;
import com.google.common.annotations.GwtIncompatible;
import java.io.Serializable;
import java.util.AbstractList;
import java.util.Arrays;
import java.util.Collection;
import java.util.Collections;
import java.util.Comparator;
import java.util.List;
import java.util.RandomAccess;
/**
* Static utility methods pertaining to {@code long} primitives, that are not
* already found in either {@link Long} or {@link Arrays}.
*
* <p>See the Guava User Guide article on <a href=
* "http://code.google.com/p/guava-libraries/wiki/PrimitivesExplained">
* primitive utilities</a>.
*
* @author Kevin Bourrillion
* @since 1.0
*/
@GwtCompatible(emulated = true)
public final class Longs {
private Longs() {}
/**
* The number of bytes required to represent a primitive {@code long}
* value.
*/
public static final int BYTES = Long.SIZE / Byte.SIZE;
/**
* The largest power of two that can be represented as a {@code long}.
*
* @since 10.0
*/
public static final long MAX_POWER_OF_TWO = 1L << (Long.SIZE - 2);
/**
* Returns a hash code for {@code value}; equal to the result of invoking
* {@code ((Long) value).hashCode()}.
*
* <p>This method always return the value specified by {@link
* Long#hashCode()} in java, which might be different from
* {@code ((Long) value).hashCode()} in GWT because {@link Long#hashCode()}
* in GWT does not obey the JRE contract.
*
* @param value a primitive {@code long} value
* @return a hash code for the value
*/
public static int hashCode(long value) {
return (int) (value ^ (value >>> 32));
}
/**
* Compares the two specified {@code long} values. The sign of the value
* returned is the same as that of {@code ((Long) a).compareTo(b)}.
*
* @param a the first {@code long} to compare
* @param b the second {@code long} to compare
* @return a negative value if {@code a} is less than {@code b}; a positive
* value if {@code a} is greater than {@code b}; or zero if they are equal
*/
public static int compare(long a, long b) {
return (a < b) ? -1 : ((a > b) ? 1 : 0);
}
/**
* Returns {@code true} if {@code target} is present as an element anywhere in
* {@code array}.
*
* @param array an array of {@code long} values, possibly empty
* @param target a primitive {@code long} value
* @return {@code true} if {@code array[i] == target} for some value of {@code
* i}
*/
public static boolean contains(long[] array, long target) {
for (long value : array) {
if (value == target) {
return true;
}
}
return false;
}
/**
* Returns the index of the first appearance of the value {@code target} in
* {@code array}.
*
* @param array an array of {@code long} values, possibly empty
* @param target a primitive {@code long} value
* @return the least index {@code i} for which {@code array[i] == target}, or
* {@code -1} if no such index exists.
*/
public static int indexOf(long[] array, long target) {
return indexOf(array, target, 0, array.length);
}
// TODO(kevinb): consider making this public
private static int indexOf(
long[] array, long target, int start, int end) {
for (int i = start; i < end; i++) {
if (array[i] == target) {
return i;
}
}
return -1;
}
/**
* Returns the start position of the first occurrence of the specified {@code
* target} within {@code array}, or {@code -1} if there is no such occurrence.
*
* <p>More formally, returns the lowest index {@code i} such that {@code
* java.util.Arrays.copyOfRange(array, i, i + target.length)} contains exactly
* the same elements as {@code target}.
*
* @param array the array to search for the sequence {@code target}
* @param target the array to search for as a sub-sequence of {@code array}
*/
public static int indexOf(long[] array, long[] target) {
checkNotNull(array, "array");
checkNotNull(target, "target");
if (target.length == 0) {
return 0;
}
outer:
for (int i = 0; i < array.length - target.length + 1; i++) {
for (int j = 0; j < target.length; j++) {
if (array[i + j] != target[j]) {
continue outer;
}
}
return i;
}
return -1;
}
/**
* Returns the index of the last appearance of the value {@code target} in
* {@code array}.
*
* @param array an array of {@code long} values, possibly empty
* @param target a primitive {@code long} value
* @return the greatest index {@code i} for which {@code array[i] == target},
* or {@code -1} if no such index exists.
*/
public static int lastIndexOf(long[] array, long target) {
return lastIndexOf(array, target, 0, array.length);
}
// TODO(kevinb): consider making this public
private static int lastIndexOf(
long[] array, long target, int start, int end) {
for (int i = end - 1; i >= start; i--) {
if (array[i] == target) {
return i;
}
}
return -1;
}
/**
* Returns the least value present in {@code array}.
*
* @param array a <i>nonempty</i> array of {@code long} values
* @return the value present in {@code array} that is less than or equal to
* every other value in the array
* @throws IllegalArgumentException if {@code array} is empty
*/
public static long min(long... array) {
checkArgument(array.length > 0);
long min = array[0];
for (int i = 1; i < array.length; i++) {
if (array[i] < min) {
min = array[i];
}
}
return min;
}
/**
* Returns the greatest value present in {@code array}.
*
* @param array a <i>nonempty</i> array of {@code long} values
* @return the value present in {@code array} that is greater than or equal to
* every other value in the array
* @throws IllegalArgumentException if {@code array} is empty
*/
public static long max(long... array) {
checkArgument(array.length > 0);
long max = array[0];
for (int i = 1; i < array.length; i++) {
if (array[i] > max) {
max = array[i];
}
}
return max;
}
/**
* Returns the values from each provided array combined into a single array.
* For example, {@code concat(new long[] {a, b}, new long[] {}, new
* long[] {c}} returns the array {@code {a, b, c}}.
*
* @param arrays zero or more {@code long} arrays
* @return a single array containing all the values from the source arrays, in
* order
*/
public static long[] concat(long[]... arrays) {
int length = 0;
for (long[] array : arrays) {
length += array.length;
}
long[] result = new long[length];
int pos = 0;
for (long[] array : arrays) {
System.arraycopy(array, 0, result, pos, array.length);
pos += array.length;
}
return result;
}
/**
* Returns a big-endian representation of {@code value} in an 8-element byte
* array; equivalent to {@code ByteBuffer.allocate(8).putLong(value).array()}.
* For example, the input value {@code 0x1213141516171819L} would yield the
* byte array {@code {0x12, 0x13, 0x14, 0x15, 0x16, 0x17, 0x18, 0x19}}.
*
* <p>If you need to convert and concatenate several values (possibly even of
* different types), use a shared {@link java.nio.ByteBuffer} instance, or use
* {@link com.google.common.io.ByteStreams#newDataOutput()} to get a growable
* buffer.
*/
@GwtIncompatible("doesn't work")
public static byte[] toByteArray(long value) {
return new byte[] {
(byte) (value >> 56),
(byte) (value >> 48),
(byte) (value >> 40),
(byte) (value >> 32),
(byte) (value >> 24),
(byte) (value >> 16),
(byte) (value >> 8),
(byte) value};
}
/**
* Returns the {@code long} value whose big-endian representation is
* stored in the first 8 bytes of {@code bytes}; equivalent to {@code
* ByteBuffer.wrap(bytes).getLong()}. For example, the input byte array
* {@code {0x12, 0x13, 0x14, 0x15, 0x16, 0x17, 0x18, 0x19}} would yield the
* {@code long} value {@code 0x1213141516171819L}.
*
* <p>Arguably, it's preferable to use {@link java.nio.ByteBuffer}; that
* library exposes much more flexibility at little cost in readability.
*
* @throws IllegalArgumentException if {@code bytes} has fewer than 8
* elements
*/
@GwtIncompatible("doesn't work")
public static long fromByteArray(byte[] bytes) {
checkArgument(bytes.length >= BYTES,
"array too small: %s < %s", bytes.length, BYTES);
return fromBytes(bytes[0], bytes[1], bytes[2], bytes[3],
bytes[4], bytes[5], bytes[6], bytes[7]) ;
}
/**
* Returns the {@code long} value whose byte representation is the given 8
* bytes, in big-endian order; equivalent to {@code Longs.fromByteArray(new
* byte[] {b1, b2, b3, b4, b5, b6, b7, b8})}.
*
* @since 7.0
*/
@GwtIncompatible("doesn't work")
public static long fromBytes(byte b1, byte b2, byte b3, byte b4,
byte b5, byte b6, byte b7, byte b8) {
return (b1 & 0xFFL) << 56
| (b2 & 0xFFL) << 48
| (b3 & 0xFFL) << 40
| (b4 & 0xFFL) << 32
| (b5 & 0xFFL) << 24
| (b6 & 0xFFL) << 16
| (b7 & 0xFFL) << 8
| (b8 & 0xFFL);
}
/**
* Returns an array containing the same values as {@code array}, but
* guaranteed to be of a specified minimum length. If {@code array} already
* has a length of at least {@code minLength}, it is returned directly.
* Otherwise, a new array of size {@code minLength + padding} is returned,
* containing the values of {@code array}, and zeroes in the remaining places.
*
* @param array the source array
* @param minLength the minimum length the returned array must guarantee
* @param padding an extra amount to "grow" the array by if growth is
* necessary
* @throws IllegalArgumentException if {@code minLength} or {@code padding} is
* negative
* @return an array containing the values of {@code array}, with guaranteed
* minimum length {@code minLength}
*/
public static long[] ensureCapacity(
long[] array, int minLength, int padding) {
checkArgument(minLength >= 0, "Invalid minLength: %s", minLength);
checkArgument(padding >= 0, "Invalid padding: %s", padding);
return (array.length < minLength)
? copyOf(array, minLength + padding)
: array;
}
// Arrays.copyOf() requires Java 6
private static long[] copyOf(long[] original, int length) {
long[] copy = new long[length];
System.arraycopy(original, 0, copy, 0, Math.min(original.length, length));
return copy;
}
/**
* Returns a string containing the supplied {@code long} values separated
* by {@code separator}. For example, {@code join("-", 1L, 2L, 3L)} returns
* the string {@code "1-2-3"}.
*
* @param separator the text that should appear between consecutive values in
* the resulting string (but not at the start or end)
* @param array an array of {@code long} values, possibly empty
*/
public static String join(String separator, long... array) {
checkNotNull(separator);
if (array.length == 0) {
return "";
}
// For pre-sizing a builder, just get the right order of magnitude
StringBuilder builder = new StringBuilder(array.length * 10);
builder.append(array[0]);
for (int i = 1; i < array.length; i++) {
builder.append(separator).append(array[i]);
}
return builder.toString();
}
/**
* Returns a comparator that compares two {@code long} arrays
* lexicographically. That is, it compares, using {@link
* #compare(long, long)}), the first pair of values that follow any
* common prefix, or when one array is a prefix of the other, treats the
* shorter array as the lesser. For example,
* {@code [] < [1L] < [1L, 2L] < [2L]}.
*
* <p>The returned comparator is inconsistent with {@link
* Object#equals(Object)} (since arrays support only identity equality), but
* it is consistent with {@link Arrays#equals(long[], long[])}.
*
* @see <a href="http://en.wikipedia.org/wiki/Lexicographical_order">
* Lexicographical order article at Wikipedia</a>
* @since 2.0
*/
public static Comparator<long[]> lexicographicalComparator() {
return LexicographicalComparator.INSTANCE;
}
private enum LexicographicalComparator implements Comparator<long[]> {
INSTANCE;
@Override
public int compare(long[] left, long[] right) {
int minLength = Math.min(left.length, right.length);
for (int i = 0; i < minLength; i++) {
int result = Longs.compare(left[i], right[i]);
if (result != 0) {
return result;
}
}
return left.length - right.length;
}
}
/**
* Copies a collection of {@code Long} instances into a new array of
* primitive {@code long} values.
*
* <p>Elements are copied from the argument collection as if by {@code
* collection.toArray()}. Calling this method is as thread-safe as calling
* that method.
*
* @param collection a collection of {@code Long} objects
* @return an array containing the same values as {@code collection}, in the
* same order, converted to primitives
* @throws NullPointerException if {@code collection} or any of its elements
* is null
*/
public static long[] toArray(Collection<Long> collection) {
if (collection instanceof LongArrayAsList) {
return ((LongArrayAsList) collection).toLongArray();
}
Object[] boxedArray = collection.toArray();
int len = boxedArray.length;
long[] array = new long[len];
for (int i = 0; i < len; i++) {
// checkNotNull for GWT (do not optimize)
array[i] = (Long) checkNotNull(boxedArray[i]);
}
return array;
}
/**
* Returns a fixed-size list backed by the specified array, similar to {@link
* Arrays#asList(Object[])}. The list supports {@link List#set(int, Object)},
* but any attempt to set a value to {@code null} will result in a {@link
* NullPointerException}.
*
* <p>The returned list maintains the values, but not the identities, of
* {@code Long} objects written to or read from it. For example, whether
* {@code list.get(0) == list.get(0)} is true for the returned list is
* unspecified.
*
* @param backingArray the array to back the list
* @return a list view of the array
*/
public static List<Long> asList(long... backingArray) {
if (backingArray.length == 0) {
return Collections.emptyList();
}
return new LongArrayAsList(backingArray);
}
@GwtCompatible
private static class LongArrayAsList extends AbstractList<Long>
implements RandomAccess, Serializable {
final long[] array;
final int start;
final int end;
LongArrayAsList(long[] array) {
this(array, 0, array.length);
}
LongArrayAsList(long[] array, int start, int end) {
this.array = array;
this.start = start;
this.end = end;
}
@Override public int size() {
return end - start;
}
@Override public boolean isEmpty() {
return false;
}
@Override public Long get(int index) {
checkElementIndex(index, size());
return array[start + index];
}
@Override public boolean contains(Object target) {
// Overridden to prevent a ton of boxing
return (target instanceof Long)
&& Longs.indexOf(array, (Long) target, start, end) != -1;
}
@Override public int indexOf(Object target) {
// Overridden to prevent a ton of boxing
if (target instanceof Long) {
int i = Longs.indexOf(array, (Long) target, start, end);
if (i >= 0) {
return i - start;
}
}
return -1;
}
@Override public int lastIndexOf(Object target) {
// Overridden to prevent a ton of boxing
if (target instanceof Long) {
int i = Longs.lastIndexOf(array, (Long) target, start, end);
if (i >= 0) {
return i - start;
}
}
return -1;
}
@Override public Long set(int index, Long element) {
checkElementIndex(index, size());
long oldValue = array[start + index];
array[start + index] = checkNotNull(element); // checkNotNull for GWT (do not optimize)
return oldValue;
}
@Override public List<Long> subList(int fromIndex, int toIndex) {
int size = size();
checkPositionIndexes(fromIndex, toIndex, size);
if (fromIndex == toIndex) {
return Collections.emptyList();
}
return new LongArrayAsList(array, start + fromIndex, start + toIndex);
}
@Override public boolean equals(Object object) {
if (object == this) {
return true;
}
if (object instanceof LongArrayAsList) {
LongArrayAsList that = (LongArrayAsList) object;
int size = size();
if (that.size() != size) {
return false;
}
for (int i = 0; i < size; i++) {
if (array[start + i] != that.array[that.start + i]) {
return false;
}
}
return true;
}
return super.equals(object);
}
@Override public int hashCode() {
int result = 1;
for (int i = start; i < end; i++) {
result = 31 * result + Longs.hashCode(array[i]);
}
return result;
}
@Override public String toString() {
StringBuilder builder = new StringBuilder(size() * 10);
builder.append('[').append(array[start]);
for (int i = start + 1; i < end; i++) {
builder.append(", ").append(array[i]);
}
return builder.append(']').toString();
}
long[] toLongArray() {
// Arrays.copyOfRange() requires Java 6
int size = size();
long[] result = new long[size];
System.arraycopy(array, start, result, 0, size);
return result;
}
private static final long serialVersionUID = 0;
}
}
| Java |
/*
* Copyright (C) 2008 The Guava Authors
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package com.google.common.primitives;
import static com.google.common.base.Preconditions.checkArgument;
import static com.google.common.base.Preconditions.checkElementIndex;
import static com.google.common.base.Preconditions.checkNotNull;
import static com.google.common.base.Preconditions.checkPositionIndexes;
import com.google.common.annotations.GwtCompatible;
import com.google.common.annotations.GwtIncompatible;
import java.io.Serializable;
import java.util.AbstractList;
import java.util.Arrays;
import java.util.Collection;
import java.util.Collections;
import java.util.Comparator;
import java.util.List;
import java.util.RandomAccess;
/**
* Static utility methods pertaining to {@code short} primitives, that are not
* already found in either {@link Short} or {@link Arrays}.
*
* <p>See the Guava User Guide article on <a href=
* "http://code.google.com/p/guava-libraries/wiki/PrimitivesExplained">
* primitive utilities</a>.
*
* @author Kevin Bourrillion
* @since 1.0
*/
@GwtCompatible(emulated = true)
public final class Shorts {
private Shorts() {}
/**
* The number of bytes required to represent a primitive {@code short}
* value.
*/
public static final int BYTES = Short.SIZE / Byte.SIZE;
/**
* The largest power of two that can be represented as a {@code short}.
*
* @since 10.0
*/
public static final short MAX_POWER_OF_TWO = 1 << (Short.SIZE - 2);
/**
* Returns a hash code for {@code value}; equal to the result of invoking
* {@code ((Short) value).hashCode()}.
*
* @param value a primitive {@code short} value
* @return a hash code for the value
*/
public static int hashCode(short value) {
return value;
}
/**
* Returns the {@code short} value that is equal to {@code value}, if
* possible.
*
* @param value any value in the range of the {@code short} type
* @return the {@code short} value that equals {@code value}
* @throws IllegalArgumentException if {@code value} is greater than {@link
* Short#MAX_VALUE} or less than {@link Short#MIN_VALUE}
*/
public static short checkedCast(long value) {
short result = (short) value;
checkArgument(result == value, "Out of range: %s", value);
return result;
}
/**
* Returns the {@code short} nearest in value to {@code value}.
*
* @param value any {@code long} value
* @return the same value cast to {@code short} if it is in the range of the
* {@code short} type, {@link Short#MAX_VALUE} if it is too large,
* or {@link Short#MIN_VALUE} if it is too small
*/
public static short saturatedCast(long value) {
if (value > Short.MAX_VALUE) {
return Short.MAX_VALUE;
}
if (value < Short.MIN_VALUE) {
return Short.MIN_VALUE;
}
return (short) value;
}
/**
* Compares the two specified {@code short} values. The sign of the value
* returned is the same as that of {@code ((Short) a).compareTo(b)}.
*
* @param a the first {@code short} to compare
* @param b the second {@code short} to compare
* @return a negative value if {@code a} is less than {@code b}; a positive
* value if {@code a} is greater than {@code b}; or zero if they are equal
*/
public static int compare(short a, short b) {
return a - b; // safe due to restricted range
}
/**
* Returns {@code true} if {@code target} is present as an element anywhere in
* {@code array}.
*
* @param array an array of {@code short} values, possibly empty
* @param target a primitive {@code short} value
* @return {@code true} if {@code array[i] == target} for some value of {@code
* i}
*/
public static boolean contains(short[] array, short target) {
for (short value : array) {
if (value == target) {
return true;
}
}
return false;
}
/**
* Returns the index of the first appearance of the value {@code target} in
* {@code array}.
*
* @param array an array of {@code short} values, possibly empty
* @param target a primitive {@code short} value
* @return the least index {@code i} for which {@code array[i] == target}, or
* {@code -1} if no such index exists.
*/
public static int indexOf(short[] array, short target) {
return indexOf(array, target, 0, array.length);
}
// TODO(kevinb): consider making this public
private static int indexOf(
short[] array, short target, int start, int end) {
for (int i = start; i < end; i++) {
if (array[i] == target) {
return i;
}
}
return -1;
}
/**
* Returns the start position of the first occurrence of the specified {@code
* target} within {@code array}, or {@code -1} if there is no such occurrence.
*
* <p>More formally, returns the lowest index {@code i} such that {@code
* java.util.Arrays.copyOfRange(array, i, i + target.length)} contains exactly
* the same elements as {@code target}.
*
* @param array the array to search for the sequence {@code target}
* @param target the array to search for as a sub-sequence of {@code array}
*/
public static int indexOf(short[] array, short[] target) {
checkNotNull(array, "array");
checkNotNull(target, "target");
if (target.length == 0) {
return 0;
}
outer:
for (int i = 0; i < array.length - target.length + 1; i++) {
for (int j = 0; j < target.length; j++) {
if (array[i + j] != target[j]) {
continue outer;
}
}
return i;
}
return -1;
}
/**
* Returns the index of the last appearance of the value {@code target} in
* {@code array}.
*
* @param array an array of {@code short} values, possibly empty
* @param target a primitive {@code short} value
* @return the greatest index {@code i} for which {@code array[i] == target},
* or {@code -1} if no such index exists.
*/
public static int lastIndexOf(short[] array, short target) {
return lastIndexOf(array, target, 0, array.length);
}
// TODO(kevinb): consider making this public
private static int lastIndexOf(
short[] array, short target, int start, int end) {
for (int i = end - 1; i >= start; i--) {
if (array[i] == target) {
return i;
}
}
return -1;
}
/**
* Returns the least value present in {@code array}.
*
* @param array a <i>nonempty</i> array of {@code short} values
* @return the value present in {@code array} that is less than or equal to
* every other value in the array
* @throws IllegalArgumentException if {@code array} is empty
*/
public static short min(short... array) {
checkArgument(array.length > 0);
short min = array[0];
for (int i = 1; i < array.length; i++) {
if (array[i] < min) {
min = array[i];
}
}
return min;
}
/**
* Returns the greatest value present in {@code array}.
*
* @param array a <i>nonempty</i> array of {@code short} values
* @return the value present in {@code array} that is greater than or equal to
* every other value in the array
* @throws IllegalArgumentException if {@code array} is empty
*/
public static short max(short... array) {
checkArgument(array.length > 0);
short max = array[0];
for (int i = 1; i < array.length; i++) {
if (array[i] > max) {
max = array[i];
}
}
return max;
}
/**
* Returns the values from each provided array combined into a single array.
* For example, {@code concat(new short[] {a, b}, new short[] {}, new
* short[] {c}} returns the array {@code {a, b, c}}.
*
* @param arrays zero or more {@code short} arrays
* @return a single array containing all the values from the source arrays, in
* order
*/
public static short[] concat(short[]... arrays) {
int length = 0;
for (short[] array : arrays) {
length += array.length;
}
short[] result = new short[length];
int pos = 0;
for (short[] array : arrays) {
System.arraycopy(array, 0, result, pos, array.length);
pos += array.length;
}
return result;
}
/**
* Returns a big-endian representation of {@code value} in a 2-element byte
* array; equivalent to {@code
* ByteBuffer.allocate(2).putShort(value).array()}. For example, the input
* value {@code (short) 0x1234} would yield the byte array {@code {0x12,
* 0x34}}.
*
* <p>If you need to convert and concatenate several values (possibly even of
* different types), use a shared {@link java.nio.ByteBuffer} instance, or use
* {@link com.google.common.io.ByteStreams#newDataOutput()} to get a growable
* buffer.
*/
@GwtIncompatible("doesn't work")
public static byte[] toByteArray(short value) {
return new byte[] {
(byte) (value >> 8),
(byte) value};
}
/**
* Returns the {@code short} value whose big-endian representation is
* stored in the first 2 bytes of {@code bytes}; equivalent to {@code
* ByteBuffer.wrap(bytes).getShort()}. For example, the input byte array
* {@code {0x54, 0x32}} would yield the {@code short} value {@code 0x5432}.
*
* <p>Arguably, it's preferable to use {@link java.nio.ByteBuffer}; that
* library exposes much more flexibility at little cost in readability.
*
* @throws IllegalArgumentException if {@code bytes} has fewer than 2
* elements
*/
@GwtIncompatible("doesn't work")
public static short fromByteArray(byte[] bytes) {
checkArgument(bytes.length >= BYTES,
"array too small: %s < %s", bytes.length, BYTES);
return fromBytes(bytes[0], bytes[1]);
}
/**
* Returns the {@code short} value whose byte representation is the given 2
* bytes, in big-endian order; equivalent to {@code Shorts.fromByteArray(new
* byte[] {b1, b2})}.
*
* @since 7.0
*/
@GwtIncompatible("doesn't work")
public static short fromBytes(byte b1, byte b2) {
return (short) ((b1 << 8) | (b2 & 0xFF));
}
/**
* Returns an array containing the same values as {@code array}, but
* guaranteed to be of a specified minimum length. If {@code array} already
* has a length of at least {@code minLength}, it is returned directly.
* Otherwise, a new array of size {@code minLength + padding} is returned,
* containing the values of {@code array}, and zeroes in the remaining places.
*
* @param array the source array
* @param minLength the minimum length the returned array must guarantee
* @param padding an extra amount to "grow" the array by if growth is
* necessary
* @throws IllegalArgumentException if {@code minLength} or {@code padding} is
* negative
* @return an array containing the values of {@code array}, with guaranteed
* minimum length {@code minLength}
*/
public static short[] ensureCapacity(
short[] array, int minLength, int padding) {
checkArgument(minLength >= 0, "Invalid minLength: %s", minLength);
checkArgument(padding >= 0, "Invalid padding: %s", padding);
return (array.length < minLength)
? copyOf(array, minLength + padding)
: array;
}
// Arrays.copyOf() requires Java 6
private static short[] copyOf(short[] original, int length) {
short[] copy = new short[length];
System.arraycopy(original, 0, copy, 0, Math.min(original.length, length));
return copy;
}
/**
* Returns a string containing the supplied {@code short} values separated
* by {@code separator}. For example, {@code join("-", (short) 1, (short) 2,
* (short) 3)} returns the string {@code "1-2-3"}.
*
* @param separator the text that should appear between consecutive values in
* the resulting string (but not at the start or end)
* @param array an array of {@code short} values, possibly empty
*/
public static String join(String separator, short... array) {
checkNotNull(separator);
if (array.length == 0) {
return "";
}
// For pre-sizing a builder, just get the right order of magnitude
StringBuilder builder = new StringBuilder(array.length * 6);
builder.append(array[0]);
for (int i = 1; i < array.length; i++) {
builder.append(separator).append(array[i]);
}
return builder.toString();
}
/**
* Returns a comparator that compares two {@code short} arrays
* lexicographically. That is, it compares, using {@link
* #compare(short, short)}), the first pair of values that follow any
* common prefix, or when one array is a prefix of the other, treats the
* shorter array as the lesser. For example, {@code [] < [(short) 1] <
* [(short) 1, (short) 2] < [(short) 2]}.
*
* <p>The returned comparator is inconsistent with {@link
* Object#equals(Object)} (since arrays support only identity equality), but
* it is consistent with {@link Arrays#equals(short[], short[])}.
*
* @see <a href="http://en.wikipedia.org/wiki/Lexicographical_order">
* Lexicographical order article at Wikipedia</a>
* @since 2.0
*/
public static Comparator<short[]> lexicographicalComparator() {
return LexicographicalComparator.INSTANCE;
}
private enum LexicographicalComparator implements Comparator<short[]> {
INSTANCE;
@Override
public int compare(short[] left, short[] right) {
int minLength = Math.min(left.length, right.length);
for (int i = 0; i < minLength; i++) {
int result = Shorts.compare(left[i], right[i]);
if (result != 0) {
return result;
}
}
return left.length - right.length;
}
}
/**
* Copies a collection of {@code Short} instances into a new array of
* primitive {@code short} values.
*
* <p>Elements are copied from the argument collection as if by {@code
* collection.toArray()}. Calling this method is as thread-safe as calling
* that method.
*
* @param collection a collection of {@code Short} objects
* @return an array containing the same values as {@code collection}, in the
* same order, converted to primitives
* @throws NullPointerException if {@code collection} or any of its elements
* is null
*/
public static short[] toArray(Collection<Short> collection) {
if (collection instanceof ShortArrayAsList) {
return ((ShortArrayAsList) collection).toShortArray();
}
Object[] boxedArray = collection.toArray();
int len = boxedArray.length;
short[] array = new short[len];
for (int i = 0; i < len; i++) {
// checkNotNull for GWT (do not optimize)
array[i] = (Short) checkNotNull(boxedArray[i]);
}
return array;
}
/**
* Returns a fixed-size list backed by the specified array, similar to {@link
* Arrays#asList(Object[])}. The list supports {@link List#set(int, Object)},
* but any attempt to set a value to {@code null} will result in a {@link
* NullPointerException}.
*
* <p>The returned list maintains the values, but not the identities, of
* {@code Short} objects written to or read from it. For example, whether
* {@code list.get(0) == list.get(0)} is true for the returned list is
* unspecified.
*
* @param backingArray the array to back the list
* @return a list view of the array
*/
public static List<Short> asList(short... backingArray) {
if (backingArray.length == 0) {
return Collections.emptyList();
}
return new ShortArrayAsList(backingArray);
}
@GwtCompatible
private static class ShortArrayAsList extends AbstractList<Short>
implements RandomAccess, Serializable {
final short[] array;
final int start;
final int end;
ShortArrayAsList(short[] array) {
this(array, 0, array.length);
}
ShortArrayAsList(short[] array, int start, int end) {
this.array = array;
this.start = start;
this.end = end;
}
@Override public int size() {
return end - start;
}
@Override public boolean isEmpty() {
return false;
}
@Override public Short get(int index) {
checkElementIndex(index, size());
return array[start + index];
}
@Override public boolean contains(Object target) {
// Overridden to prevent a ton of boxing
return (target instanceof Short)
&& Shorts.indexOf(array, (Short) target, start, end) != -1;
}
@Override public int indexOf(Object target) {
// Overridden to prevent a ton of boxing
if (target instanceof Short) {
int i = Shorts.indexOf(array, (Short) target, start, end);
if (i >= 0) {
return i - start;
}
}
return -1;
}
@Override public int lastIndexOf(Object target) {
// Overridden to prevent a ton of boxing
if (target instanceof Short) {
int i = Shorts.lastIndexOf(array, (Short) target, start, end);
if (i >= 0) {
return i - start;
}
}
return -1;
}
@Override public Short set(int index, Short element) {
checkElementIndex(index, size());
short oldValue = array[start + index];
array[start + index] = checkNotNull(element); // checkNotNull for GWT (do not optimize)
return oldValue;
}
@Override public List<Short> subList(int fromIndex, int toIndex) {
int size = size();
checkPositionIndexes(fromIndex, toIndex, size);
if (fromIndex == toIndex) {
return Collections.emptyList();
}
return new ShortArrayAsList(array, start + fromIndex, start + toIndex);
}
@Override public boolean equals(Object object) {
if (object == this) {
return true;
}
if (object instanceof ShortArrayAsList) {
ShortArrayAsList that = (ShortArrayAsList) object;
int size = size();
if (that.size() != size) {
return false;
}
for (int i = 0; i < size; i++) {
if (array[start + i] != that.array[that.start + i]) {
return false;
}
}
return true;
}
return super.equals(object);
}
@Override public int hashCode() {
int result = 1;
for (int i = start; i < end; i++) {
result = 31 * result + Shorts.hashCode(array[i]);
}
return result;
}
@Override public String toString() {
StringBuilder builder = new StringBuilder(size() * 6);
builder.append('[').append(array[start]);
for (int i = start + 1; i < end; i++) {
builder.append(", ").append(array[i]);
}
return builder.append(']').toString();
}
short[] toShortArray() {
// Arrays.copyOfRange() requires Java 6
int size = size();
short[] result = new short[size];
System.arraycopy(array, start, result, 0, size);
return result;
}
private static final long serialVersionUID = 0;
}
}
| Java |
/*
* Copyright (C) 2011 The Guava Authors
*
* Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except
* in compliance with the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software distributed under the
* License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either
* express or implied. See the License for the specific language governing permissions and
* limitations under the License.
*/
package com.google.common.primitives;
import static com.google.common.base.Preconditions.checkArgument;
import static com.google.common.base.Preconditions.checkNotNull;
import java.util.Arrays;
import java.util.Comparator;
import com.google.common.annotations.Beta;
import com.google.common.annotations.GwtCompatible;
/**
* Static utility methods pertaining to {@code int} primitives that interpret values as
* <i>unsigned</i> (that is, any negative value {@code x} is treated as the positive value
* {@code 2^32 + x}). The methods for which signedness is not an issue are in {@link Ints}, as well
* as signed versions of methods for which signedness is an issue.
*
* <p>In addition, this class provides several static methods for converting an {@code int} to a
* {@code String} and a {@code String} to an {@code int} that treat the {@code int} as an unsigned
* number.
*
* <p>Users of these utilities must be <i>extremely careful</i> not to mix up signed and unsigned
* {@code int} values. When possible, it is recommended that the {@link UnsignedInteger} wrapper
* class be used, at a small efficiency penalty, to enforce the distinction in the type system.
*
* <p>See the Guava User Guide article on <a href=
* "http://code.google.com/p/guava-libraries/wiki/PrimitivesExplained#Unsigned_support">
* unsigned primitive utilities</a>.
*
* @author Louis Wasserman
* @since 11.0
*/
@Beta
@GwtCompatible
public final class UnsignedInts {
static final long INT_MASK = 0xffffffffL;
private UnsignedInts() {}
static int flip(int value) {
return value ^ Integer.MIN_VALUE;
}
/**
* Compares the two specified {@code int} values, treating them as unsigned values between
* {@code 0} and {@code 2^32 - 1} inclusive.
*
* @param a the first unsigned {@code int} to compare
* @param b the second unsigned {@code int} to compare
* @return a negative value if {@code a} is less than {@code b}; a positive value if {@code a} is
* greater than {@code b}; or zero if they are equal
*/
public static int compare(int a, int b) {
return Ints.compare(flip(a), flip(b));
}
/**
* Returns the value of the given {@code int} as a {@code long}, when treated as unsigned.
*/
public static long toLong(int value) {
return value & INT_MASK;
}
/**
* Returns the least value present in {@code array}, treating values as unsigned.
*
* @param array a <i>nonempty</i> array of unsigned {@code int} values
* @return the value present in {@code array} that is less than or equal to every other value in
* the array according to {@link #compare}
* @throws IllegalArgumentException if {@code array} is empty
*/
public static int min(int... array) {
checkArgument(array.length > 0);
int min = flip(array[0]);
for (int i = 1; i < array.length; i++) {
int next = flip(array[i]);
if (next < min) {
min = next;
}
}
return flip(min);
}
/**
* Returns the greatest value present in {@code array}, treating values as unsigned.
*
* @param array a <i>nonempty</i> array of unsigned {@code int} values
* @return the value present in {@code array} that is greater than or equal to every other value
* in the array according to {@link #compare}
* @throws IllegalArgumentException if {@code array} is empty
*/
public static int max(int... array) {
checkArgument(array.length > 0);
int max = flip(array[0]);
for (int i = 1; i < array.length; i++) {
int next = flip(array[i]);
if (next > max) {
max = next;
}
}
return flip(max);
}
/**
* Returns a string containing the supplied unsigned {@code int} values separated by
* {@code separator}. For example, {@code join("-", 1, 2, 3)} returns the string {@code "1-2-3"}.
*
* @param separator the text that should appear between consecutive values in the resulting
* string (but not at the start or end)
* @param array an array of unsigned {@code int} values, possibly empty
*/
public static String join(String separator, int... array) {
checkNotNull(separator);
if (array.length == 0) {
return "";
}
// For pre-sizing a builder, just get the right order of magnitude
StringBuilder builder = new StringBuilder(array.length * 5);
builder.append(array[0]);
for (int i = 1; i < array.length; i++) {
builder.append(separator).append(toString(array[i]));
}
return builder.toString();
}
/**
* Returns a comparator that compares two arrays of unsigned {@code int} values lexicographically.
* That is, it compares, using {@link #compare(int, int)}), the first pair of values that follow
* any common prefix, or when one array is a prefix of the other, treats the shorter array as the
* lesser. For example, {@code [] < [1] < [1, 2] < [2] < [1 << 31]}.
*
* <p>The returned comparator is inconsistent with {@link Object#equals(Object)} (since arrays
* support only identity equality), but it is consistent with {@link Arrays#equals(int[], int[])}.
*
* @see <a href="http://en.wikipedia.org/wiki/Lexicographical_order"> Lexicographical order
* article at Wikipedia</a>
*/
public static Comparator<int[]> lexicographicalComparator() {
return LexicographicalComparator.INSTANCE;
}
enum LexicographicalComparator implements Comparator<int[]> {
INSTANCE;
@Override
public int compare(int[] left, int[] right) {
int minLength = Math.min(left.length, right.length);
for (int i = 0; i < minLength; i++) {
if (left[i] != right[i]) {
return UnsignedInts.compare(left[i], right[i]);
}
}
return left.length - right.length;
}
}
/**
* Returns dividend / divisor, where the dividend and divisor are treated as unsigned 32-bit
* quantities.
*
* @param dividend the dividend (numerator)
* @param divisor the divisor (denominator)
* @throws ArithmeticException if divisor is 0
*/
public static int divide(int dividend, int divisor) {
return (int) (toLong(dividend) / toLong(divisor));
}
/**
* Returns dividend % divisor, where the dividend and divisor are treated as unsigned 32-bit
* quantities.
*
* @param dividend the dividend (numerator)
* @param divisor the divisor (denominator)
* @throws ArithmeticException if divisor is 0
*/
public static int remainder(int dividend, int divisor) {
return (int) (toLong(dividend) % toLong(divisor));
}
/**
* Returns the unsigned {@code int} value represented by the given decimal string.
*
* @throws NumberFormatException if the string does not contain a valid unsigned integer, or if
* the value represented is too large to fit in an unsigned {@code int}.
* @throws NullPointerException if {@code s} is null
*/
public static int parseUnsignedInt(String s) {
return parseUnsignedInt(s, 10);
}
/**
* Returns the unsigned {@code int} value represented by a string with the given radix.
*
* @param string the string containing the unsigned integer representation to be parsed.
* @param radix the radix to use while parsing {@code s}; must be between
* {@link Character#MIN_RADIX} and {@link Character#MAX_RADIX}.
* @throws NumberFormatException if the string does not contain a valid unsigned {@code int}, or
* if supplied radix is invalid.
*/
public static int parseUnsignedInt(String string, int radix) {
checkNotNull(string);
long result = Long.parseLong(string, radix);
if ((result & INT_MASK) != result) {
throw new NumberFormatException("Input " + string + " in base " + radix
+ " is not in the range of an unsigned integer");
}
return (int) result;
}
/**
* Returns a string representation of x, where x is treated as unsigned.
*/
public static String toString(int x) {
return toString(x, 10);
}
/**
* Returns a string representation of {@code x} for the given radix, where {@code x} is treated
* as unsigned.
*
* @param x the value to convert to a string.
* @param radix the radix to use while working with {@code x}
* @throws IllegalArgumentException if {@code radix} is not between {@link Character#MIN_RADIX}
* and {@link Character#MAX_RADIX}.
*/
public static String toString(int x, int radix) {
long asLong = x & INT_MASK;
return Long.toString(asLong, radix);
}
}
| Java |
/*
* Copyright (C) 2010 The Guava Authors
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
/**
* Static utilities for working with the eight primitive types and {@code void},
* and value types for treating them as unsigned.
*
* <p>This package is a part of the open-source
* <a href="http://guava-libraries.googlecode.com">Guava libraries</a>.
*
* <p>See the Guava User Guide article on <a href=
* "http://code.google.com/p/guava-libraries/wiki/PrimitivesExplained">
* primitive utilities</a>.
*
* <h2>Contents</h2>
*
* <h3>General static utilities</h3>
*
* <ul>
* <li>{@link com.google.common.primitives.Primitives}
* </ul>
*
* <h3>Per-type static utilities</h3>
*
* <ul>
* <li>{@link com.google.common.primitives.Booleans}
* <li>{@link com.google.common.primitives.Bytes}
* <ul>
* <li>{@link com.google.common.primitives.SignedBytes}
* <li>{@link com.google.common.primitives.UnsignedBytes}
* </ul>
* <li>{@link com.google.common.primitives.Chars}
* <li>{@link com.google.common.primitives.Doubles}
* <li>{@link com.google.common.primitives.Floats}
* <li>{@link com.google.common.primitives.Ints}
* <ul>
* <li>{@link com.google.common.primitives.UnsignedInts}
* </ul>
* <li>{@link com.google.common.primitives.Longs}
* <ul>
* <li>{@link com.google.common.primitives.UnsignedLongs}
* </ul>
* <li>{@link com.google.common.primitives.Shorts}
* </ul>
*
* <h3>Value types</h3>
* <ul>
* <li>{@link com.google.common.primitives.UnsignedInteger}
* <li>{@link com.google.common.primitives.UnsignedLong}
* </ul>
*/
@ParametersAreNonnullByDefault
package com.google.common.primitives;
import javax.annotation.ParametersAreNonnullByDefault;
| Java |
/*
* Copyright (C) 2011 The Guava Authors
*
* Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except
* in compliance with the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software distributed under the
* License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either
* express or implied. See the License for the specific language governing permissions and
* limitations under the License.
*/
package com.google.common.primitives;
import static com.google.common.base.Preconditions.checkArgument;
import static com.google.common.base.Preconditions.checkNotNull;
import java.math.BigInteger;
import java.util.Arrays;
import java.util.Comparator;
import com.google.common.annotations.Beta;
import com.google.common.annotations.GwtCompatible;
/**
* Static utility methods pertaining to {@code long} primitives that interpret values as
* <i>unsigned</i> (that is, any negative value {@code x} is treated as the positive value
* {@code 2^64 + x}). The methods for which signedness is not an issue are in {@link Longs}, as
* well as signed versions of methods for which signedness is an issue.
*
* <p>In addition, this class provides several static methods for converting a {@code long} to a
* {@code String} and a {@code String} to a {@code long} that treat the {@code long} as an unsigned
* number.
*
* <p>Users of these utilities must be <i>extremely careful</i> not to mix up signed and unsigned
* {@code long} values. When possible, it is recommended that the {@link UnsignedLong} wrapper
* class be used, at a small efficiency penalty, to enforce the distinction in the type system.
*
* <p>See the Guava User Guide article on <a href=
* "http://code.google.com/p/guava-libraries/wiki/PrimitivesExplained#Unsigned_support">
* unsigned primitive utilities</a>.
*
* @author Louis Wasserman
* @author Brian Milch
* @author Colin Evans
* @since 10.0
*/
@Beta
@GwtCompatible
public final class UnsignedLongs {
private UnsignedLongs() {}
public static final long MAX_VALUE = -1L; // Equivalent to 2^64 - 1
/**
* A (self-inverse) bijection which converts the ordering on unsigned longs to the ordering on
* longs, that is, {@code a <= b} as unsigned longs if and only if {@code rotate(a) <= rotate(b)}
* as signed longs.
*/
private static long flip(long a) {
return a ^ Long.MIN_VALUE;
}
/**
* Compares the two specified {@code long} values, treating them as unsigned values between
* {@code 0} and {@code 2^64 - 1} inclusive.
*
* @param a the first unsigned {@code long} to compare
* @param b the second unsigned {@code long} to compare
* @return a negative value if {@code a} is less than {@code b}; a positive value if {@code a} is
* greater than {@code b}; or zero if they are equal
*/
public static int compare(long a, long b) {
return Longs.compare(flip(a), flip(b));
}
/**
* Returns the least value present in {@code array}, treating values as unsigned.
*
* @param array a <i>nonempty</i> array of unsigned {@code long} values
* @return the value present in {@code array} that is less than or equal to every other value in
* the array according to {@link #compare}
* @throws IllegalArgumentException if {@code array} is empty
*/
public static long min(long... array) {
checkArgument(array.length > 0);
long min = flip(array[0]);
for (int i = 1; i < array.length; i++) {
long next = flip(array[i]);
if (next < min) {
min = next;
}
}
return flip(min);
}
/**
* Returns the greatest value present in {@code array}, treating values as unsigned.
*
* @param array a <i>nonempty</i> array of unsigned {@code long} values
* @return the value present in {@code array} that is greater than or equal to every other value
* in the array according to {@link #compare}
* @throws IllegalArgumentException if {@code array} is empty
*/
public static long max(long... array) {
checkArgument(array.length > 0);
long max = flip(array[0]);
for (int i = 1; i < array.length; i++) {
long next = flip(array[i]);
if (next > max) {
max = next;
}
}
return flip(max);
}
/**
* Returns a string containing the supplied unsigned {@code long} values separated by
* {@code separator}. For example, {@code join("-", 1, 2, 3)} returns the string {@code "1-2-3"}.
*
* @param separator the text that should appear between consecutive values in the resulting
* string (but not at the start or end)
* @param array an array of unsigned {@code long} values, possibly empty
*/
public static String join(String separator, long... array) {
checkNotNull(separator);
if (array.length == 0) {
return "";
}
// For pre-sizing a builder, just get the right order of magnitude
StringBuilder builder = new StringBuilder(array.length * 5);
builder.append(array[0]);
for (int i = 1; i < array.length; i++) {
builder.append(separator).append(toString(array[i]));
}
return builder.toString();
}
/**
* Returns a comparator that compares two arrays of unsigned {@code long} values
* lexicographically. That is, it compares, using {@link #compare(long, long)}), the first pair of
* values that follow any common prefix, or when one array is a prefix of the other, treats the
* shorter array as the lesser. For example, {@code [] < [1L] < [1L, 2L] < [2L] < [1L << 63]}.
*
* <p>The returned comparator is inconsistent with {@link Object#equals(Object)} (since arrays
* support only identity equality), but it is consistent with
* {@link Arrays#equals(long[], long[])}.
*
* @see <a href="http://en.wikipedia.org/wiki/Lexicographical_order">Lexicographical order
* article at Wikipedia</a>
*/
public static Comparator<long[]> lexicographicalComparator() {
return LexicographicalComparator.INSTANCE;
}
enum LexicographicalComparator implements Comparator<long[]> {
INSTANCE;
@Override
public int compare(long[] left, long[] right) {
int minLength = Math.min(left.length, right.length);
for (int i = 0; i < minLength; i++) {
if (left[i] != right[i]) {
return UnsignedLongs.compare(left[i], right[i]);
}
}
return left.length - right.length;
}
}
/**
* Returns dividend / divisor, where the dividend and divisor are treated as unsigned 64-bit
* quantities.
*
* @param dividend the dividend (numerator)
* @param divisor the divisor (denominator)
* @throws ArithmeticException if divisor is 0
*/
public static long divide(long dividend, long divisor) {
if (divisor < 0) { // i.e., divisor >= 2^63:
if (compare(dividend, divisor) < 0) {
return 0; // dividend < divisor
} else {
return 1; // dividend >= divisor
}
}
// Optimization - use signed division if dividend < 2^63
if (dividend >= 0) {
return dividend / divisor;
}
/*
* Otherwise, approximate the quotient, check, and correct if necessary. Our approximation is
* guaranteed to be either exact or one less than the correct value. This follows from fact
* that floor(floor(x)/i) == floor(x/i) for any real x and integer i != 0. The proof is not
* quite trivial.
*/
long quotient = ((dividend >>> 1) / divisor) << 1;
long rem = dividend - quotient * divisor;
return quotient + (compare(rem, divisor) >= 0 ? 1 : 0);
}
/**
* Returns dividend % divisor, where the dividend and divisor are treated as unsigned 64-bit
* quantities.
*
* @param dividend the dividend (numerator)
* @param divisor the divisor (denominator)
* @throws ArithmeticException if divisor is 0
* @since 11.0
*/
public static long remainder(long dividend, long divisor) {
if (divisor < 0) { // i.e., divisor >= 2^63:
if (compare(dividend, divisor) < 0) {
return dividend; // dividend < divisor
} else {
return dividend - divisor; // dividend >= divisor
}
}
// Optimization - use signed modulus if dividend < 2^63
if (dividend >= 0) {
return dividend % divisor;
}
/*
* Otherwise, approximate the quotient, check, and correct if necessary. Our approximation is
* guaranteed to be either exact or one less than the correct value. This follows from fact
* that floor(floor(x)/i) == floor(x/i) for any real x and integer i != 0. The proof is not
* quite trivial.
*/
long quotient = ((dividend >>> 1) / divisor) << 1;
long rem = dividend - quotient * divisor;
return rem - (compare(rem, divisor) >= 0 ? divisor : 0);
}
/**
* Returns the unsigned {@code long} value represented by the given decimal string.
*
* @throws NumberFormatException if the string does not contain a valid unsigned {@code long}
* value
*/
public static long parseUnsignedLong(String s) {
return parseUnsignedLong(s, 10);
}
/**
* Returns the unsigned {@code long} value represented by a string with the given radix.
*
* @param s the string containing the unsigned {@code long} representation to be parsed.
* @param radix the radix to use while parsing {@code s}
* @throws NumberFormatException if the string does not contain a valid unsigned {@code long}
* with the given radix, or if {@code radix} is not between {@link Character#MIN_RADIX}
* and {@link Character#MAX_RADIX}.
*/
public static long parseUnsignedLong(String s, int radix) {
checkNotNull(s);
if (s.length() == 0) {
throw new NumberFormatException("empty string");
}
if (radix < Character.MIN_RADIX || radix > Character.MAX_RADIX) {
throw new NumberFormatException("illegal radix:" + radix);
}
int max_safe_pos = maxSafeDigits[radix] - 1;
long value = 0;
for (int pos = 0; pos < s.length(); pos++) {
int digit = Character.digit(s.charAt(pos), radix);
if (digit == -1) {
throw new NumberFormatException(s);
}
if (pos > max_safe_pos && overflowInParse(value, digit, radix)) {
throw new NumberFormatException("Too large for unsigned long: " + s);
}
value = (value * radix) + digit;
}
return value;
}
/**
* Returns true if (current * radix) + digit is a number too large to be represented by an
* unsigned long. This is useful for detecting overflow while parsing a string representation of
* a number. Does not verify whether supplied radix is valid, passing an invalid radix will give
* undefined results or an ArrayIndexOutOfBoundsException.
*/
private static boolean overflowInParse(long current, int digit, int radix) {
if (current >= 0) {
if (current < maxValueDivs[radix]) {
return false;
}
if (current > maxValueDivs[radix]) {
return true;
}
// current == maxValueDivs[radix]
return (digit > maxValueMods[radix]);
}
// current < 0: high bit is set
return true;
}
/**
* Returns a string representation of x, where x is treated as unsigned.
*/
public static String toString(long x) {
return toString(x, 10);
}
/**
* Returns a string representation of {@code x} for the given radix, where {@code x} is treated
* as unsigned.
*
* @param x the value to convert to a string.
* @param radix the radix to use while working with {@code x}
* @throws IllegalArgumentException if {@code radix} is not between {@link Character#MIN_RADIX}
* and {@link Character#MAX_RADIX}.
*/
public static String toString(long x, int radix) {
checkArgument(radix >= Character.MIN_RADIX && radix <= Character.MAX_RADIX,
"radix (%s) must be between Character.MIN_RADIX and Character.MAX_RADIX", radix);
if (x == 0) {
// Simply return "0"
return "0";
} else {
char[] buf = new char[64];
int i = buf.length;
if (x < 0) {
// Split x into high-order and low-order halves.
// Individual digits are generated from the bottom half into which
// bits are moved continously from the top half.
long top = x >>> 32;
long bot = (x & 0xffffffffl) + ((top % radix) << 32);
top /= radix;
while ((bot > 0) || (top > 0)) {
buf[--i] = Character.forDigit((int) (bot % radix), radix);
bot = (bot / radix) + ((top % radix) << 32);
top /= radix;
}
} else {
// Simple modulo/division approach
while (x > 0) {
buf[--i] = Character.forDigit((int) (x % radix), radix);
x /= radix;
}
}
// Generate string
return new String(buf, i, buf.length - i);
}
}
// calculated as 0xffffffffffffffff / radix
private static final long[] maxValueDivs = new long[Character.MAX_RADIX + 1];
private static final int[] maxValueMods = new int[Character.MAX_RADIX + 1];
private static final int[] maxSafeDigits = new int[Character.MAX_RADIX + 1];
static {
BigInteger overflow = new BigInteger("10000000000000000", 16);
for (int i = Character.MIN_RADIX; i <= Character.MAX_RADIX; i++) {
maxValueDivs[i] = divide(MAX_VALUE, i);
maxValueMods[i] = (int) remainder(MAX_VALUE, i);
maxSafeDigits[i] = overflow.toString(i).length() - 1;
}
}
}
| Java |
/*
* Copyright (C) 2008 The Guava Authors
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package com.google.common.primitives;
import static com.google.common.base.Preconditions.checkArgument;
import static com.google.common.base.Preconditions.checkElementIndex;
import static com.google.common.base.Preconditions.checkNotNull;
import static com.google.common.base.Preconditions.checkPositionIndexes;
import static java.lang.Double.NEGATIVE_INFINITY;
import static java.lang.Double.POSITIVE_INFINITY;
import com.google.common.annotations.GwtCompatible;
import java.io.Serializable;
import java.util.AbstractList;
import java.util.Arrays;
import java.util.Collection;
import java.util.Collections;
import java.util.Comparator;
import java.util.List;
import java.util.RandomAccess;
/**
* Static utility methods pertaining to {@code double} primitives, that are not
* already found in either {@link Double} or {@link Arrays}.
*
* <p>See the Guava User Guide article on <a href=
* "http://code.google.com/p/guava-libraries/wiki/PrimitivesExplained">
* primitive utilities</a>.
*
* @author Kevin Bourrillion
* @since 1.0
*/
@GwtCompatible
public final class Doubles {
private Doubles() {}
/**
* The number of bytes required to represent a primitive {@code double}
* value.
*
* @since 10.0
*/
public static final int BYTES = Double.SIZE / Byte.SIZE;
/**
* Returns a hash code for {@code value}; equal to the result of invoking
* {@code ((Double) value).hashCode()}.
*
* @param value a primitive {@code double} value
* @return a hash code for the value
*/
public static int hashCode(double value) {
return ((Double) value).hashCode();
// TODO(kevinb): do it this way when we can (GWT problem):
// long bits = Double.doubleToLongBits(value);
// return (int)(bits ^ (bits >>> 32));
}
/**
* Compares the two specified {@code double} values. The sign of the value
* returned is the same as that of <code>((Double) a).{@linkplain
* Double#compareTo compareTo}(b)</code>. As with that method, {@code NaN} is
* treated as greater than all other values, and {@code 0.0 > -0.0}.
*
* @param a the first {@code double} to compare
* @param b the second {@code double} to compare
* @return a negative value if {@code a} is less than {@code b}; a positive
* value if {@code a} is greater than {@code b}; or zero if they are equal
*/
public static int compare(double a, double b) {
return Double.compare(a, b);
}
/**
* Returns {@code true} if {@code value} represents a real number. This is
* equivalent to, but not necessarily implemented as,
* {@code !(Double.isInfinite(value) || Double.isNaN(value))}.
*
* @since 10.0
*/
public static boolean isFinite(double value) {
return NEGATIVE_INFINITY < value & value < POSITIVE_INFINITY;
}
/**
* Returns {@code true} if {@code target} is present as an element anywhere in
* {@code array}. Note that this always returns {@code false} when {@code
* target} is {@code NaN}.
*
* @param array an array of {@code double} values, possibly empty
* @param target a primitive {@code double} value
* @return {@code true} if {@code array[i] == target} for some value of {@code
* i}
*/
public static boolean contains(double[] array, double target) {
for (double value : array) {
if (value == target) {
return true;
}
}
return false;
}
/**
* Returns the index of the first appearance of the value {@code target} in
* {@code array}. Note that this always returns {@code -1} when {@code target}
* is {@code NaN}.
*
* @param array an array of {@code double} values, possibly empty
* @param target a primitive {@code double} value
* @return the least index {@code i} for which {@code array[i] == target}, or
* {@code -1} if no such index exists.
*/
public static int indexOf(double[] array, double target) {
return indexOf(array, target, 0, array.length);
}
// TODO(kevinb): consider making this public
private static int indexOf(
double[] array, double target, int start, int end) {
for (int i = start; i < end; i++) {
if (array[i] == target) {
return i;
}
}
return -1;
}
/**
* Returns the start position of the first occurrence of the specified {@code
* target} within {@code array}, or {@code -1} if there is no such occurrence.
*
* <p>More formally, returns the lowest index {@code i} such that {@code
* java.util.Arrays.copyOfRange(array, i, i + target.length)} contains exactly
* the same elements as {@code target}.
*
* <p>Note that this always returns {@code -1} when {@code target} contains
* {@code NaN}.
*
* @param array the array to search for the sequence {@code target}
* @param target the array to search for as a sub-sequence of {@code array}
*/
public static int indexOf(double[] array, double[] target) {
checkNotNull(array, "array");
checkNotNull(target, "target");
if (target.length == 0) {
return 0;
}
outer:
for (int i = 0; i < array.length - target.length + 1; i++) {
for (int j = 0; j < target.length; j++) {
if (array[i + j] != target[j]) {
continue outer;
}
}
return i;
}
return -1;
}
/**
* Returns the index of the last appearance of the value {@code target} in
* {@code array}. Note that this always returns {@code -1} when {@code target}
* is {@code NaN}.
*
* @param array an array of {@code double} values, possibly empty
* @param target a primitive {@code double} value
* @return the greatest index {@code i} for which {@code array[i] == target},
* or {@code -1} if no such index exists.
*/
public static int lastIndexOf(double[] array, double target) {
return lastIndexOf(array, target, 0, array.length);
}
// TODO(kevinb): consider making this public
private static int lastIndexOf(
double[] array, double target, int start, int end) {
for (int i = end - 1; i >= start; i--) {
if (array[i] == target) {
return i;
}
}
return -1;
}
/**
* Returns the least value present in {@code array}, using the same rules of
* comparison as {@link Math#min(double, double)}.
*
* @param array a <i>nonempty</i> array of {@code double} values
* @return the value present in {@code array} that is less than or equal to
* every other value in the array
* @throws IllegalArgumentException if {@code array} is empty
*/
public static double min(double... array) {
checkArgument(array.length > 0);
double min = array[0];
for (int i = 1; i < array.length; i++) {
min = Math.min(min, array[i]);
}
return min;
}
/**
* Returns the greatest value present in {@code array}, using the same rules
* of comparison as {@link Math#max(double, double)}.
*
* @param array a <i>nonempty</i> array of {@code double} values
* @return the value present in {@code array} that is greater than or equal to
* every other value in the array
* @throws IllegalArgumentException if {@code array} is empty
*/
public static double max(double... array) {
checkArgument(array.length > 0);
double max = array[0];
for (int i = 1; i < array.length; i++) {
max = Math.max(max, array[i]);
}
return max;
}
/**
* Returns the values from each provided array combined into a single array.
* For example, {@code concat(new double[] {a, b}, new double[] {}, new
* double[] {c}} returns the array {@code {a, b, c}}.
*
* @param arrays zero or more {@code double} arrays
* @return a single array containing all the values from the source arrays, in
* order
*/
public static double[] concat(double[]... arrays) {
int length = 0;
for (double[] array : arrays) {
length += array.length;
}
double[] result = new double[length];
int pos = 0;
for (double[] array : arrays) {
System.arraycopy(array, 0, result, pos, array.length);
pos += array.length;
}
return result;
}
/**
* Returns an array containing the same values as {@code array}, but
* guaranteed to be of a specified minimum length. If {@code array} already
* has a length of at least {@code minLength}, it is returned directly.
* Otherwise, a new array of size {@code minLength + padding} is returned,
* containing the values of {@code array}, and zeroes in the remaining places.
*
* @param array the source array
* @param minLength the minimum length the returned array must guarantee
* @param padding an extra amount to "grow" the array by if growth is
* necessary
* @throws IllegalArgumentException if {@code minLength} or {@code padding} is
* negative
* @return an array containing the values of {@code array}, with guaranteed
* minimum length {@code minLength}
*/
public static double[] ensureCapacity(
double[] array, int minLength, int padding) {
checkArgument(minLength >= 0, "Invalid minLength: %s", minLength);
checkArgument(padding >= 0, "Invalid padding: %s", padding);
return (array.length < minLength)
? copyOf(array, minLength + padding)
: array;
}
// Arrays.copyOf() requires Java 6
private static double[] copyOf(double[] original, int length) {
double[] copy = new double[length];
System.arraycopy(original, 0, copy, 0, Math.min(original.length, length));
return copy;
}
/**
* Returns a string containing the supplied {@code double} values, converted
* to strings as specified by {@link Double#toString(double)}, and separated
* by {@code separator}. For example, {@code join("-", 1.0, 2.0, 3.0)} returns
* the string {@code "1.0-2.0-3.0"}.
*
* <p>Note that {@link Double#toString(double)} formats {@code double}
* differently in GWT sometimes. In the previous example, it returns the string
* {@code "1-2-3"}.
*
* @param separator the text that should appear between consecutive values in
* the resulting string (but not at the start or end)
* @param array an array of {@code double} values, possibly empty
*/
public static String join(String separator, double... array) {
checkNotNull(separator);
if (array.length == 0) {
return "";
}
// For pre-sizing a builder, just get the right order of magnitude
StringBuilder builder = new StringBuilder(array.length * 12);
builder.append(array[0]);
for (int i = 1; i < array.length; i++) {
builder.append(separator).append(array[i]);
}
return builder.toString();
}
/**
* Returns a comparator that compares two {@code double} arrays
* lexicographically. That is, it compares, using {@link
* #compare(double, double)}), the first pair of values that follow any
* common prefix, or when one array is a prefix of the other, treats the
* shorter array as the lesser. For example,
* {@code [] < [1.0] < [1.0, 2.0] < [2.0]}.
*
* <p>The returned comparator is inconsistent with {@link
* Object#equals(Object)} (since arrays support only identity equality), but
* it is consistent with {@link Arrays#equals(double[], double[])}.
*
* @see <a href="http://en.wikipedia.org/wiki/Lexicographical_order">
* Lexicographical order article at Wikipedia</a>
* @since 2.0
*/
public static Comparator<double[]> lexicographicalComparator() {
return LexicographicalComparator.INSTANCE;
}
private enum LexicographicalComparator implements Comparator<double[]> {
INSTANCE;
@Override
public int compare(double[] left, double[] right) {
int minLength = Math.min(left.length, right.length);
for (int i = 0; i < minLength; i++) {
int result = Doubles.compare(left[i], right[i]);
if (result != 0) {
return result;
}
}
return left.length - right.length;
}
}
/**
* Copies a collection of {@code Double} instances into a new array of
* primitive {@code double} values.
*
* <p>Elements are copied from the argument collection as if by {@code
* collection.toArray()}. Calling this method is as thread-safe as calling
* that method.
*
* @param collection a collection of {@code Double} objects
* @return an array containing the same values as {@code collection}, in the
* same order, converted to primitives
* @throws NullPointerException if {@code collection} or any of its elements
* is null
*/
public static double[] toArray(Collection<Double> collection) {
if (collection instanceof DoubleArrayAsList) {
return ((DoubleArrayAsList) collection).toDoubleArray();
}
Object[] boxedArray = collection.toArray();
int len = boxedArray.length;
double[] array = new double[len];
for (int i = 0; i < len; i++) {
// checkNotNull for GWT (do not optimize)
array[i] = (Double) checkNotNull(boxedArray[i]);
}
return array;
}
/**
* Returns a fixed-size list backed by the specified array, similar to {@link
* Arrays#asList(Object[])}. The list supports {@link List#set(int, Object)},
* but any attempt to set a value to {@code null} will result in a {@link
* NullPointerException}.
*
* <p>The returned list maintains the values, but not the identities, of
* {@code Double} objects written to or read from it. For example, whether
* {@code list.get(0) == list.get(0)} is true for the returned list is
* unspecified.
*
* <p>The returned list may have unexpected behavior if it contains {@code
* NaN}, or if {@code NaN} is used as a parameter to any of its methods.
*
* @param backingArray the array to back the list
* @return a list view of the array
*/
public static List<Double> asList(double... backingArray) {
if (backingArray.length == 0) {
return Collections.emptyList();
}
return new DoubleArrayAsList(backingArray);
}
@GwtCompatible
private static class DoubleArrayAsList extends AbstractList<Double>
implements RandomAccess, Serializable {
final double[] array;
final int start;
final int end;
DoubleArrayAsList(double[] array) {
this(array, 0, array.length);
}
DoubleArrayAsList(double[] array, int start, int end) {
this.array = array;
this.start = start;
this.end = end;
}
@Override public int size() {
return end - start;
}
@Override public boolean isEmpty() {
return false;
}
@Override public Double get(int index) {
checkElementIndex(index, size());
return array[start + index];
}
@Override public boolean contains(Object target) {
// Overridden to prevent a ton of boxing
return (target instanceof Double)
&& Doubles.indexOf(array, (Double) target, start, end) != -1;
}
@Override public int indexOf(Object target) {
// Overridden to prevent a ton of boxing
if (target instanceof Double) {
int i = Doubles.indexOf(array, (Double) target, start, end);
if (i >= 0) {
return i - start;
}
}
return -1;
}
@Override public int lastIndexOf(Object target) {
// Overridden to prevent a ton of boxing
if (target instanceof Double) {
int i = Doubles.lastIndexOf(array, (Double) target, start, end);
if (i >= 0) {
return i - start;
}
}
return -1;
}
@Override public Double set(int index, Double element) {
checkElementIndex(index, size());
double oldValue = array[start + index];
array[start + index] = checkNotNull(element); // checkNotNull for GWT (do not optimize)
return oldValue;
}
@Override public List<Double> subList(int fromIndex, int toIndex) {
int size = size();
checkPositionIndexes(fromIndex, toIndex, size);
if (fromIndex == toIndex) {
return Collections.emptyList();
}
return new DoubleArrayAsList(array, start + fromIndex, start + toIndex);
}
@Override public boolean equals(Object object) {
if (object == this) {
return true;
}
if (object instanceof DoubleArrayAsList) {
DoubleArrayAsList that = (DoubleArrayAsList) object;
int size = size();
if (that.size() != size) {
return false;
}
for (int i = 0; i < size; i++) {
if (array[start + i] != that.array[that.start + i]) {
return false;
}
}
return true;
}
return super.equals(object);
}
@Override public int hashCode() {
int result = 1;
for (int i = start; i < end; i++) {
result = 31 * result + Doubles.hashCode(array[i]);
}
return result;
}
@Override public String toString() {
StringBuilder builder = new StringBuilder(size() * 12);
builder.append('[').append(array[start]);
for (int i = start + 1; i < end; i++) {
builder.append(", ").append(array[i]);
}
return builder.append(']').toString();
}
double[] toDoubleArray() {
// Arrays.copyOfRange() requires Java 6
int size = size();
double[] result = new double[size];
System.arraycopy(array, start, result, 0, size);
return result;
}
private static final long serialVersionUID = 0;
}
}
| Java |
/*
* Copyright (C) 2007 The Guava Authors
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package com.google.common.primitives;
import static com.google.common.base.Preconditions.checkNotNull;
import java.util.Collections;
import java.util.HashMap;
import java.util.Map;
import java.util.Set;
/**
* Contains static utility methods pertaining to primitive types and their
* corresponding wrapper types.
*
* @author Kevin Bourrillion
* @since 1.0
*/
public final class Primitives {
private Primitives() {}
/** A map from primitive types to their corresponding wrapper types. */
private static final Map<Class<?>, Class<?>> PRIMITIVE_TO_WRAPPER_TYPE;
/** A map from wrapper types to their corresponding primitive types. */
private static final Map<Class<?>, Class<?>> WRAPPER_TO_PRIMITIVE_TYPE;
// Sad that we can't use a BiMap. :(
static {
Map<Class<?>, Class<?>> primToWrap = new HashMap<Class<?>, Class<?>>(16);
Map<Class<?>, Class<?>> wrapToPrim = new HashMap<Class<?>, Class<?>>(16);
add(primToWrap, wrapToPrim, boolean.class, Boolean.class);
add(primToWrap, wrapToPrim, byte.class, Byte.class);
add(primToWrap, wrapToPrim, char.class, Character.class);
add(primToWrap, wrapToPrim, double.class, Double.class);
add(primToWrap, wrapToPrim, float.class, Float.class);
add(primToWrap, wrapToPrim, int.class, Integer.class);
add(primToWrap, wrapToPrim, long.class, Long.class);
add(primToWrap, wrapToPrim, short.class, Short.class);
add(primToWrap, wrapToPrim, void.class, Void.class);
PRIMITIVE_TO_WRAPPER_TYPE = Collections.unmodifiableMap(primToWrap);
WRAPPER_TO_PRIMITIVE_TYPE = Collections.unmodifiableMap(wrapToPrim);
}
private static void add(Map<Class<?>, Class<?>> forward,
Map<Class<?>, Class<?>> backward, Class<?> key, Class<?> value) {
forward.put(key, value);
backward.put(value, key);
}
/**
* Returns an immutable set of all nine primitive types (including {@code
* void}). Note that a simpler way to test whether a {@code Class} instance
* is a member of this set is to call {@link Class#isPrimitive}.
*
* @since 3.0
*/
public static Set<Class<?>> allPrimitiveTypes() {
return PRIMITIVE_TO_WRAPPER_TYPE.keySet();
}
/**
* Returns an immutable set of all nine primitive-wrapper types (including
* {@link Void}).
*
* @since 3.0
*/
public static Set<Class<?>> allWrapperTypes() {
return WRAPPER_TO_PRIMITIVE_TYPE.keySet();
}
/**
* Returns {@code true} if {@code type} is one of the nine
* primitive-wrapper types, such as {@link Integer}.
*
* @see Class#isPrimitive
*/
public static boolean isWrapperType(Class<?> type) {
return WRAPPER_TO_PRIMITIVE_TYPE.containsKey(checkNotNull(type));
}
/**
* Returns the corresponding wrapper type of {@code type} if it is a primitive
* type; otherwise returns {@code type} itself. Idempotent.
* <pre>
* wrap(int.class) == Integer.class
* wrap(Integer.class) == Integer.class
* wrap(String.class) == String.class
* </pre>
*/
public static <T> Class<T> wrap(Class<T> type) {
checkNotNull(type);
// cast is safe: long.class and Long.class are both of type Class<Long>
@SuppressWarnings("unchecked")
Class<T> wrapped = (Class<T>) PRIMITIVE_TO_WRAPPER_TYPE.get(type);
return (wrapped == null) ? type : wrapped;
}
/**
* Returns the corresponding primitive type of {@code type} if it is a
* wrapper type; otherwise returns {@code type} itself. Idempotent.
* <pre>
* unwrap(Integer.class) == int.class
* unwrap(int.class) == int.class
* unwrap(String.class) == String.class
* </pre>
*/
public static <T> Class<T> unwrap(Class<T> type) {
checkNotNull(type);
// cast is safe: long.class and Long.class are both of type Class<Long>
@SuppressWarnings("unchecked")
Class<T> unwrapped = (Class<T>) WRAPPER_TO_PRIMITIVE_TYPE.get(type);
return (unwrapped == null) ? type : unwrapped;
}
}
| Java |
/*
* Copyright (C) 2011 The Guava Authors
*
* Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except
* in compliance with the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software distributed under the
* License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either
* express or implied. See the License for the specific language governing permissions and
* limitations under the License.
*/
package com.google.common.primitives;
import static com.google.common.base.Preconditions.checkArgument;
import static com.google.common.base.Preconditions.checkNotNull;
import static com.google.common.primitives.UnsignedInts.INT_MASK;
import static com.google.common.primitives.UnsignedInts.compare;
import static com.google.common.primitives.UnsignedInts.toLong;
import java.math.BigInteger;
import javax.annotation.Nullable;
import com.google.common.annotations.Beta;
import com.google.common.annotations.GwtCompatible;
import com.google.common.annotations.GwtIncompatible;
/**
* A wrapper class for unsigned {@code int} values, supporting arithmetic operations.
*
* <p>In some cases, when speed is more important than code readability, it may be faster simply to
* treat primitive {@code int} values as unsigned, using the methods from {@link UnsignedInts}.
*
* <p>See the Guava User Guide article on <a href=
* "http://code.google.com/p/guava-libraries/wiki/PrimitivesExplained#Unsigned_support">
* unsigned primitive utilities</a>.
*
* @author Louis Wasserman
* @since 11.0
*/
@Beta
@GwtCompatible(emulated = true)
public final class UnsignedInteger extends Number implements Comparable<UnsignedInteger> {
public static final UnsignedInteger ZERO = asUnsigned(0);
public static final UnsignedInteger ONE = asUnsigned(1);
public static final UnsignedInteger MAX_VALUE = asUnsigned(-1);
private final int value;
private UnsignedInteger(int value) {
this.value = value & 0xffffffff;
}
/**
* Returns an {@code UnsignedInteger} that, when treated as signed, is
* equal to {@code value}.
*/
public static UnsignedInteger asUnsigned(int value) {
return new UnsignedInteger(value);
}
/**
* Returns an {@code UnsignedInteger} that is equal to {@code value},
* if possible. The inverse operation of {@link #longValue()}.
*/
public static UnsignedInteger valueOf(long value) {
checkArgument((value & INT_MASK) == value,
"value (%s) is outside the range for an unsigned integer value", value);
return asUnsigned((int) value);
}
/**
* Returns a {@code UnsignedInteger} representing the same value as the specified
* {@link BigInteger}. This is the inverse operation of {@link #bigIntegerValue()}.
*
* @throws IllegalArgumentException if {@code value} is negative or {@code value >= 2^32}
*/
public static UnsignedInteger valueOf(BigInteger value) {
checkNotNull(value);
checkArgument(value.signum() >= 0 && value.bitLength() <= Integer.SIZE,
"value (%s) is outside the range for an unsigned integer value", value);
return asUnsigned(value.intValue());
}
/**
* Returns an {@code UnsignedInteger} holding the value of the specified {@code String}, parsed
* as an unsigned {@code int} value.
*
* @throws NumberFormatException if the string does not contain a parsable unsigned {@code int}
* value
*/
public static UnsignedInteger valueOf(String string) {
return valueOf(string, 10);
}
/**
* Returns an {@code UnsignedInteger} holding the value of the specified {@code String}, parsed
* as an unsigned {@code int} value in the specified radix.
*
* @throws NumberFormatException if the string does not contain a parsable unsigned {@code int}
* value
*/
public static UnsignedInteger valueOf(String string, int radix) {
return asUnsigned(UnsignedInts.parseUnsignedInt(string, radix));
}
/**
* Returns the result of adding this and {@code val}. If the result would have more than 32 bits,
* returns the low 32 bits of the result.
*/
public UnsignedInteger add(UnsignedInteger val) {
checkNotNull(val);
return asUnsigned(this.value + val.value);
}
/**
* Returns the result of subtracting this and {@code val}. If the result would be negative,
* returns the low 32 bits of the result.
*/
public UnsignedInteger subtract(UnsignedInteger val) {
checkNotNull(val);
return asUnsigned(this.value - val.value);
}
/**
* Returns the result of multiplying this and {@code val}. If the result would have more than 32
* bits, returns the low 32 bits of the result.
*/
@GwtIncompatible("Does not truncate correctly")
public UnsignedInteger multiply(UnsignedInteger val) {
checkNotNull(val);
return asUnsigned(value * val.value);
}
/**
* Returns the result of dividing this by {@code val}.
*/
public UnsignedInteger divide(UnsignedInteger val) {
checkNotNull(val);
return asUnsigned(UnsignedInts.divide(value, val.value));
}
/**
* Returns the remainder of dividing this by {@code val}.
*/
public UnsignedInteger remainder(UnsignedInteger val) {
checkNotNull(val);
return asUnsigned(UnsignedInts.remainder(value, val.value));
}
/**
* Returns the value of this {@code UnsignedInteger} as an {@code int}. This is an inverse
* operation to {@link #asUnsigned}.
*
* <p>Note that if this {@code UnsignedInteger} holds a value {@code >= 2^31}, the returned value
* will be equal to {@code this - 2^32}.
*/
@Override
public int intValue() {
return value;
}
/**
* Returns the value of this {@code UnsignedInteger} as a {@code long}.
*/
@Override
public long longValue() {
return toLong(value);
}
/**
* Returns the value of this {@code UnsignedInteger} as a {@code float}, analogous to a widening
* primitive conversion from {@code int} to {@code float}, and correctly rounded.
*/
@Override
public float floatValue() {
return longValue();
}
/**
* Returns the value of this {@code UnsignedInteger} as a {@code float}, analogous to a widening
* primitive conversion from {@code int} to {@code double}, and correctly rounded.
*/
@Override
public double doubleValue() {
return longValue();
}
/**
* Returns the value of this {@code UnsignedInteger} as a {@link BigInteger}.
*/
public BigInteger bigIntegerValue() {
return BigInteger.valueOf(longValue());
}
/**
* Compares this unsigned integer to another unsigned integer.
* Returns {@code 0} if they are equal, a negative number if {@code this < other},
* and a positive number if {@code this > other}.
*/
@Override
public int compareTo(UnsignedInteger other) {
checkNotNull(other);
return compare(value, other.value);
}
@Override
public int hashCode() {
return value;
}
@Override
public boolean equals(@Nullable Object obj) {
if (obj instanceof UnsignedInteger) {
UnsignedInteger other = (UnsignedInteger) obj;
return value == other.value;
}
return false;
}
/**
* Returns a string representation of the {@code UnsignedInteger} value, in base 10.
*/
@Override
public String toString() {
return toString(10);
}
/**
* Returns a string representation of the {@code UnsignedInteger} value, in base {@code radix}.
* If {@code radix < Character.MIN_RADIX} or {@code radix > Character.MAX_RADIX}, the radix
* {@code 10} is used.
*/
public String toString(int radix) {
return UnsignedInts.toString(value, radix);
}
}
| Java |
/*
* Copyright (C) 2008 The Guava Authors
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package com.google.common.primitives;
import static com.google.common.base.Preconditions.checkArgument;
import static com.google.common.base.Preconditions.checkElementIndex;
import static com.google.common.base.Preconditions.checkNotNull;
import static com.google.common.base.Preconditions.checkPositionIndexes;
import static java.lang.Float.NEGATIVE_INFINITY;
import static java.lang.Float.POSITIVE_INFINITY;
import com.google.common.annotations.GwtCompatible;
import java.io.Serializable;
import java.util.AbstractList;
import java.util.Arrays;
import java.util.Collection;
import java.util.Collections;
import java.util.Comparator;
import java.util.List;
import java.util.RandomAccess;
/**
* Static utility methods pertaining to {@code float} primitives, that are not
* already found in either {@link Float} or {@link Arrays}.
*
* <p>See the Guava User Guide article on <a href=
* "http://code.google.com/p/guava-libraries/wiki/PrimitivesExplained">
* primitive utilities</a>.
*
* @author Kevin Bourrillion
* @since 1.0
*/
@GwtCompatible
public final class Floats {
private Floats() {}
/**
* The number of bytes required to represent a primitive {@code float}
* value.
*
* @since 10.0
*/
public static final int BYTES = Float.SIZE / Byte.SIZE;
/**
* Returns a hash code for {@code value}; equal to the result of invoking
* {@code ((Float) value).hashCode()}.
*
* @param value a primitive {@code float} value
* @return a hash code for the value
*/
public static int hashCode(float value) {
// TODO(kevinb): is there a better way, that's still gwt-safe?
return ((Float) value).hashCode();
}
/**
* Compares the two specified {@code float} values using {@link
* Float#compare(float, float)}. You may prefer to invoke that method
* directly; this method exists only for consistency with the other utilities
* in this package.
*
* @param a the first {@code float} to compare
* @param b the second {@code float} to compare
* @return the result of invoking {@link Float#compare(float, float)}
*/
public static int compare(float a, float b) {
return Float.compare(a, b);
}
/**
* Returns {@code true} if {@code value} represents a real number. This is
* equivalent to, but not necessarily implemented as,
* {@code !(Float.isInfinite(value) || Float.isNaN(value))}.
*
* @since 10.0
*/
public static boolean isFinite(float value) {
return NEGATIVE_INFINITY < value & value < POSITIVE_INFINITY;
}
/**
* Returns {@code true} if {@code target} is present as an element anywhere in
* {@code array}. Note that this always returns {@code false} when {@code
* target} is {@code NaN}.
*
* @param array an array of {@code float} values, possibly empty
* @param target a primitive {@code float} value
* @return {@code true} if {@code array[i] == target} for some value of {@code
* i}
*/
public static boolean contains(float[] array, float target) {
for (float value : array) {
if (value == target) {
return true;
}
}
return false;
}
/**
* Returns the index of the first appearance of the value {@code target} in
* {@code array}. Note that this always returns {@code -1} when {@code target}
* is {@code NaN}.
*
* @param array an array of {@code float} values, possibly empty
* @param target a primitive {@code float} value
* @return the least index {@code i} for which {@code array[i] == target}, or
* {@code -1} if no such index exists.
*/
public static int indexOf(float[] array, float target) {
return indexOf(array, target, 0, array.length);
}
// TODO(kevinb): consider making this public
private static int indexOf(
float[] array, float target, int start, int end) {
for (int i = start; i < end; i++) {
if (array[i] == target) {
return i;
}
}
return -1;
}
/**
* Returns the start position of the first occurrence of the specified {@code
* target} within {@code array}, or {@code -1} if there is no such occurrence.
*
* <p>More formally, returns the lowest index {@code i} such that {@code
* java.util.Arrays.copyOfRange(array, i, i + target.length)} contains exactly
* the same elements as {@code target}.
*
* <p>Note that this always returns {@code -1} when {@code target} contains
* {@code NaN}.
*
* @param array the array to search for the sequence {@code target}
* @param target the array to search for as a sub-sequence of {@code array}
*/
public static int indexOf(float[] array, float[] target) {
checkNotNull(array, "array");
checkNotNull(target, "target");
if (target.length == 0) {
return 0;
}
outer:
for (int i = 0; i < array.length - target.length + 1; i++) {
for (int j = 0; j < target.length; j++) {
if (array[i + j] != target[j]) {
continue outer;
}
}
return i;
}
return -1;
}
/**
* Returns the index of the last appearance of the value {@code target} in
* {@code array}. Note that this always returns {@code -1} when {@code target}
* is {@code NaN}.
*
* @param array an array of {@code float} values, possibly empty
* @param target a primitive {@code float} value
* @return the greatest index {@code i} for which {@code array[i] == target},
* or {@code -1} if no such index exists.
*/
public static int lastIndexOf(float[] array, float target) {
return lastIndexOf(array, target, 0, array.length);
}
// TODO(kevinb): consider making this public
private static int lastIndexOf(
float[] array, float target, int start, int end) {
for (int i = end - 1; i >= start; i--) {
if (array[i] == target) {
return i;
}
}
return -1;
}
/**
* Returns the least value present in {@code array}, using the same rules of
* comparison as {@link Math#min(float, float)}.
*
* @param array a <i>nonempty</i> array of {@code float} values
* @return the value present in {@code array} that is less than or equal to
* every other value in the array
* @throws IllegalArgumentException if {@code array} is empty
*/
public static float min(float... array) {
checkArgument(array.length > 0);
float min = array[0];
for (int i = 1; i < array.length; i++) {
min = Math.min(min, array[i]);
}
return min;
}
/**
* Returns the greatest value present in {@code array}, using the same rules
* of comparison as {@link Math#min(float, float)}.
*
* @param array a <i>nonempty</i> array of {@code float} values
* @return the value present in {@code array} that is greater than or equal to
* every other value in the array
* @throws IllegalArgumentException if {@code array} is empty
*/
public static float max(float... array) {
checkArgument(array.length > 0);
float max = array[0];
for (int i = 1; i < array.length; i++) {
max = Math.max(max, array[i]);
}
return max;
}
/**
* Returns the values from each provided array combined into a single array.
* For example, {@code concat(new float[] {a, b}, new float[] {}, new
* float[] {c}} returns the array {@code {a, b, c}}.
*
* @param arrays zero or more {@code float} arrays
* @return a single array containing all the values from the source arrays, in
* order
*/
public static float[] concat(float[]... arrays) {
int length = 0;
for (float[] array : arrays) {
length += array.length;
}
float[] result = new float[length];
int pos = 0;
for (float[] array : arrays) {
System.arraycopy(array, 0, result, pos, array.length);
pos += array.length;
}
return result;
}
/**
* Returns an array containing the same values as {@code array}, but
* guaranteed to be of a specified minimum length. If {@code array} already
* has a length of at least {@code minLength}, it is returned directly.
* Otherwise, a new array of size {@code minLength + padding} is returned,
* containing the values of {@code array}, and zeroes in the remaining places.
*
* @param array the source array
* @param minLength the minimum length the returned array must guarantee
* @param padding an extra amount to "grow" the array by if growth is
* necessary
* @throws IllegalArgumentException if {@code minLength} or {@code padding} is
* negative
* @return an array containing the values of {@code array}, with guaranteed
* minimum length {@code minLength}
*/
public static float[] ensureCapacity(
float[] array, int minLength, int padding) {
checkArgument(minLength >= 0, "Invalid minLength: %s", minLength);
checkArgument(padding >= 0, "Invalid padding: %s", padding);
return (array.length < minLength)
? copyOf(array, minLength + padding)
: array;
}
// Arrays.copyOf() requires Java 6
private static float[] copyOf(float[] original, int length) {
float[] copy = new float[length];
System.arraycopy(original, 0, copy, 0, Math.min(original.length, length));
return copy;
}
/**
* Returns a string containing the supplied {@code float} values, converted
* to strings as specified by {@link Float#toString(float)}, and separated by
* {@code separator}. For example, {@code join("-", 1.0f, 2.0f, 3.0f)}
* returns the string {@code "1.0-2.0-3.0"}.
*
* <p>Note that {@link Float#toString(float)} formats {@code float}
* differently in GWT. In the previous example, it returns the string {@code
* "1-2-3"}.
*
* @param separator the text that should appear between consecutive values in
* the resulting string (but not at the start or end)
* @param array an array of {@code float} values, possibly empty
*/
public static String join(String separator, float... array) {
checkNotNull(separator);
if (array.length == 0) {
return "";
}
// For pre-sizing a builder, just get the right order of magnitude
StringBuilder builder = new StringBuilder(array.length * 12);
builder.append(array[0]);
for (int i = 1; i < array.length; i++) {
builder.append(separator).append(array[i]);
}
return builder.toString();
}
/**
* Returns a comparator that compares two {@code float} arrays
* lexicographically. That is, it compares, using {@link
* #compare(float, float)}), the first pair of values that follow any
* common prefix, or when one array is a prefix of the other, treats the
* shorter array as the lesser. For example, {@code [] < [1.0f] < [1.0f, 2.0f]
* < [2.0f]}.
*
* <p>The returned comparator is inconsistent with {@link
* Object#equals(Object)} (since arrays support only identity equality), but
* it is consistent with {@link Arrays#equals(float[], float[])}.
*
* @see <a href="http://en.wikipedia.org/wiki/Lexicographical_order">
* Lexicographical order article at Wikipedia</a>
* @since 2.0
*/
public static Comparator<float[]> lexicographicalComparator() {
return LexicographicalComparator.INSTANCE;
}
private enum LexicographicalComparator implements Comparator<float[]> {
INSTANCE;
@Override
public int compare(float[] left, float[] right) {
int minLength = Math.min(left.length, right.length);
for (int i = 0; i < minLength; i++) {
int result = Floats.compare(left[i], right[i]);
if (result != 0) {
return result;
}
}
return left.length - right.length;
}
}
/**
* Copies a collection of {@code Float} instances into a new array of
* primitive {@code float} values.
*
* <p>Elements are copied from the argument collection as if by {@code
* collection.toArray()}. Calling this method is as thread-safe as calling
* that method.
*
* @param collection a collection of {@code Float} objects
* @return an array containing the same values as {@code collection}, in the
* same order, converted to primitives
* @throws NullPointerException if {@code collection} or any of its elements
* is null
*/
public static float[] toArray(Collection<Float> collection) {
if (collection instanceof FloatArrayAsList) {
return ((FloatArrayAsList) collection).toFloatArray();
}
Object[] boxedArray = collection.toArray();
int len = boxedArray.length;
float[] array = new float[len];
for (int i = 0; i < len; i++) {
// checkNotNull for GWT (do not optimize)
array[i] = (Float) checkNotNull(boxedArray[i]);
}
return array;
}
/**
* Returns a fixed-size list backed by the specified array, similar to {@link
* Arrays#asList(Object[])}. The list supports {@link List#set(int, Object)},
* but any attempt to set a value to {@code null} will result in a {@link
* NullPointerException}.
*
* <p>The returned list maintains the values, but not the identities, of
* {@code Float} objects written to or read from it. For example, whether
* {@code list.get(0) == list.get(0)} is true for the returned list is
* unspecified.
*
* <p>The returned list may have unexpected behavior if it contains {@code
* NaN}, or if {@code NaN} is used as a parameter to any of its methods.
*
* @param backingArray the array to back the list
* @return a list view of the array
*/
public static List<Float> asList(float... backingArray) {
if (backingArray.length == 0) {
return Collections.emptyList();
}
return new FloatArrayAsList(backingArray);
}
@GwtCompatible
private static class FloatArrayAsList extends AbstractList<Float>
implements RandomAccess, Serializable {
final float[] array;
final int start;
final int end;
FloatArrayAsList(float[] array) {
this(array, 0, array.length);
}
FloatArrayAsList(float[] array, int start, int end) {
this.array = array;
this.start = start;
this.end = end;
}
@Override public int size() {
return end - start;
}
@Override public boolean isEmpty() {
return false;
}
@Override public Float get(int index) {
checkElementIndex(index, size());
return array[start + index];
}
@Override public boolean contains(Object target) {
// Overridden to prevent a ton of boxing
return (target instanceof Float)
&& Floats.indexOf(array, (Float) target, start, end) != -1;
}
@Override public int indexOf(Object target) {
// Overridden to prevent a ton of boxing
if (target instanceof Float) {
int i = Floats.indexOf(array, (Float) target, start, end);
if (i >= 0) {
return i - start;
}
}
return -1;
}
@Override public int lastIndexOf(Object target) {
// Overridden to prevent a ton of boxing
if (target instanceof Float) {
int i = Floats.lastIndexOf(array, (Float) target, start, end);
if (i >= 0) {
return i - start;
}
}
return -1;
}
@Override public Float set(int index, Float element) {
checkElementIndex(index, size());
float oldValue = array[start + index];
array[start + index] = checkNotNull(element); // checkNotNull for GWT (do not optimize)
return oldValue;
}
@Override public List<Float> subList(int fromIndex, int toIndex) {
int size = size();
checkPositionIndexes(fromIndex, toIndex, size);
if (fromIndex == toIndex) {
return Collections.emptyList();
}
return new FloatArrayAsList(array, start + fromIndex, start + toIndex);
}
@Override public boolean equals(Object object) {
if (object == this) {
return true;
}
if (object instanceof FloatArrayAsList) {
FloatArrayAsList that = (FloatArrayAsList) object;
int size = size();
if (that.size() != size) {
return false;
}
for (int i = 0; i < size; i++) {
if (array[start + i] != that.array[that.start + i]) {
return false;
}
}
return true;
}
return super.equals(object);
}
@Override public int hashCode() {
int result = 1;
for (int i = start; i < end; i++) {
result = 31 * result + Floats.hashCode(array[i]);
}
return result;
}
@Override public String toString() {
StringBuilder builder = new StringBuilder(size() * 12);
builder.append('[').append(array[start]);
for (int i = start + 1; i < end; i++) {
builder.append(", ").append(array[i]);
}
return builder.append(']').toString();
}
float[] toFloatArray() {
// Arrays.copyOfRange() requires Java 6
int size = size();
float[] result = new float[size];
System.arraycopy(array, start, result, 0, size);
return result;
}
private static final long serialVersionUID = 0;
}
}
| Java |
/*
* Copyright (C) 2009 The Guava Authors
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package com.google.common.primitives;
import static com.google.common.base.Preconditions.checkArgument;
import static com.google.common.base.Preconditions.checkNotNull;
import com.google.common.annotations.GwtCompatible;
import java.util.Comparator;
/**
* Static utility methods pertaining to {@code byte} primitives that
* interpret values as signed. The corresponding methods that treat the values
* as unsigned are found in {@link UnsignedBytes}, and the methods for which
* signedness is not an issue are in {@link Bytes}.
*
* <p>See the Guava User Guide article on <a href=
* "http://code.google.com/p/guava-libraries/wiki/PrimitivesExplained">
* primitive utilities</a>.
*
* @author Kevin Bourrillion
* @since 1.0
*/
// TODO(kevinb): how to prevent warning on UnsignedBytes when building GWT
// javadoc?
@GwtCompatible
public final class SignedBytes {
private SignedBytes() {}
/**
* The largest power of two that can be represented as a signed {@code byte}.
*
* @since 10.0
*/
public static final byte MAX_POWER_OF_TWO = 1 << 6;
/**
* Returns the {@code byte} value that is equal to {@code value}, if possible.
*
* @param value any value in the range of the {@code byte} type
* @return the {@code byte} value that equals {@code value}
* @throws IllegalArgumentException if {@code value} is greater than {@link
* Byte#MAX_VALUE} or less than {@link Byte#MIN_VALUE}
*/
public static byte checkedCast(long value) {
byte result = (byte) value;
checkArgument(result == value, "Out of range: %s", value);
return result;
}
/**
* Returns the {@code byte} nearest in value to {@code value}.
*
* @param value any {@code long} value
* @return the same value cast to {@code byte} if it is in the range of the
* {@code byte} type, {@link Byte#MAX_VALUE} if it is too large,
* or {@link Byte#MIN_VALUE} if it is too small
*/
public static byte saturatedCast(long value) {
if (value > Byte.MAX_VALUE) {
return Byte.MAX_VALUE;
}
if (value < Byte.MIN_VALUE) {
return Byte.MIN_VALUE;
}
return (byte) value;
}
/**
* Compares the two specified {@code byte} values. The sign of the value
* returned is the same as that of {@code ((Byte) a).compareTo(b)}.
*
* @param a the first {@code byte} to compare
* @param b the second {@code byte} to compare
* @return a negative value if {@code a} is less than {@code b}; a positive
* value if {@code a} is greater than {@code b}; or zero if they are equal
*/
public static int compare(byte a, byte b) {
return a - b; // safe due to restricted range
}
/**
* Returns the least value present in {@code array}.
*
* @param array a <i>nonempty</i> array of {@code byte} values
* @return the value present in {@code array} that is less than or equal to
* every other value in the array
* @throws IllegalArgumentException if {@code array} is empty
*/
public static byte min(byte... array) {
checkArgument(array.length > 0);
byte min = array[0];
for (int i = 1; i < array.length; i++) {
if (array[i] < min) {
min = array[i];
}
}
return min;
}
/**
* Returns the greatest value present in {@code array}.
*
* @param array a <i>nonempty</i> array of {@code byte} values
* @return the value present in {@code array} that is greater than or equal to
* every other value in the array
* @throws IllegalArgumentException if {@code array} is empty
*/
public static byte max(byte... array) {
checkArgument(array.length > 0);
byte max = array[0];
for (int i = 1; i < array.length; i++) {
if (array[i] > max) {
max = array[i];
}
}
return max;
}
/**
* Returns a string containing the supplied {@code byte} values separated
* by {@code separator}. For example, {@code join(":", 0x01, 0x02, -0x01)}
* returns the string {@code "1:2:-1"}.
*
* @param separator the text that should appear between consecutive values in
* the resulting string (but not at the start or end)
* @param array an array of {@code byte} values, possibly empty
*/
public static String join(String separator, byte... array) {
checkNotNull(separator);
if (array.length == 0) {
return "";
}
// For pre-sizing a builder, just get the right order of magnitude
StringBuilder builder = new StringBuilder(array.length * 5);
builder.append(array[0]);
for (int i = 1; i < array.length; i++) {
builder.append(separator).append(array[i]);
}
return builder.toString();
}
/**
* Returns a comparator that compares two {@code byte} arrays
* lexicographically. That is, it compares, using {@link
* #compare(byte, byte)}), the first pair of values that follow any common
* prefix, or when one array is a prefix of the other, treats the shorter
* array as the lesser. For example, {@code [] < [0x01] < [0x01, 0x80] <
* [0x01, 0x7F] < [0x02]}. Values are treated as signed.
*
* <p>The returned comparator is inconsistent with {@link
* Object#equals(Object)} (since arrays support only identity equality), but
* it is consistent with {@link java.util.Arrays#equals(byte[], byte[])}.
*
* @see <a href="http://en.wikipedia.org/wiki/Lexicographical_order">
* Lexicographical order article at Wikipedia</a>
* @since 2.0
*/
public static Comparator<byte[]> lexicographicalComparator() {
return LexicographicalComparator.INSTANCE;
}
private enum LexicographicalComparator implements Comparator<byte[]> {
INSTANCE;
@Override
public int compare(byte[] left, byte[] right) {
int minLength = Math.min(left.length, right.length);
for (int i = 0; i < minLength; i++) {
int result = SignedBytes.compare(left[i], right[i]);
if (result != 0) {
return result;
}
}
return left.length - right.length;
}
}
}
| Java |
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