code stringlengths 3 1.18M | language stringclasses 1 value |
|---|---|
/*
* 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 java.io.Serializable;
import java.util.AbstractList;
import java.util.Arrays;
import java.util.Collection;
import java.util.Collections;
import java.util.List;
import java.util.RandomAccess;
/**
* Static utility methods pertaining to {@code byte} primitives, that are not
* already found in either {@link Byte} or {@link Arrays}, <i>and interpret
* bytes as neither signed nor unsigned</i>. The methods which specifically
* treat bytes as signed or unsigned are found in {@link SignedBytes} and {@link
* UnsignedBytes}.
*
* <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 Bytes {
private Bytes() {}
/**
* Returns a hash code for {@code value}; equal to the result of invoking
* {@code ((Byte) value).hashCode()}.
*
* @param value a primitive {@code byte} value
* @return a hash code for the value
*/
public static int hashCode(byte value) {
return value;
}
/**
* Returns {@code true} if {@code target} is present as an element anywhere in
* {@code array}.
*
* @param array an array of {@code byte} values, possibly empty
* @param target a primitive {@code byte} value
* @return {@code true} if {@code array[i] == target} for some value of {@code
* i}
*/
public static boolean contains(byte[] array, byte target) {
for (byte 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 byte} values, possibly empty
* @param target a primitive {@code byte} 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(byte[] array, byte target) {
return indexOf(array, target, 0, array.length);
}
// TODO(kevinb): consider making this public
private static int indexOf(
byte[] array, byte 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(byte[] array, byte[] 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 byte} values, possibly empty
* @param target a primitive {@code byte} 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(byte[] array, byte target) {
return lastIndexOf(array, target, 0, array.length);
}
// TODO(kevinb): consider making this public
private static int lastIndexOf(
byte[] array, byte target, int start, int end) {
for (int i = end - 1; i >= start; i--) {
if (array[i] == target) {
return i;
}
}
return -1;
}
/**
* Returns the values from each provided array combined into a single array.
* For example, {@code concat(new byte[] {a, b}, new byte[] {}, new
* byte[] {c}} returns the array {@code {a, b, c}}.
*
* @param arrays zero or more {@code byte} arrays
* @return a single array containing all the values from the source arrays, in
* order
*/
public static byte[] concat(byte[]... arrays) {
int length = 0;
for (byte[] array : arrays) {
length += array.length;
}
byte[] result = new byte[length];
int pos = 0;
for (byte[] 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 byte[] ensureCapacity(
byte[] 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 byte[] copyOf(byte[] original, int length) {
byte[] copy = new byte[length];
System.arraycopy(original, 0, copy, 0, Math.min(original.length, length));
return copy;
}
/**
* Copies a collection of {@code Byte} instances into a new array of
* primitive {@code byte} 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 Byte} 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 byte[] toArray(Collection<Byte> collection) {
if (collection instanceof ByteArrayAsList) {
return ((ByteArrayAsList) collection).toByteArray();
}
Object[] boxedArray = collection.toArray();
int len = boxedArray.length;
byte[] array = new byte[len];
for (int i = 0; i < len; i++) {
// checkNotNull for GWT (do not optimize)
array[i] = (Byte) 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 Byte} 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<Byte> asList(byte... backingArray) {
if (backingArray.length == 0) {
return Collections.emptyList();
}
return new ByteArrayAsList(backingArray);
}
@GwtCompatible
private static class ByteArrayAsList extends AbstractList<Byte>
implements RandomAccess, Serializable {
final byte[] array;
final int start;
final int end;
ByteArrayAsList(byte[] array) {
this(array, 0, array.length);
}
ByteArrayAsList(byte[] 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 Byte 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 Byte)
&& Bytes.indexOf(array, (Byte) target, start, end) != -1;
}
@Override public int indexOf(Object target) {
// Overridden to prevent a ton of boxing
if (target instanceof Byte) {
int i = Bytes.indexOf(array, (Byte) 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 Byte) {
int i = Bytes.lastIndexOf(array, (Byte) target, start, end);
if (i >= 0) {
return i - start;
}
}
return -1;
}
@Override public Byte set(int index, Byte element) {
checkElementIndex(index, size());
byte oldValue = array[start + index];
array[start + index] = checkNotNull(element); // checkNotNull for GWT (do not optimize)
return oldValue;
}
@Override public List<Byte> subList(int fromIndex, int toIndex) {
int size = size();
checkPositionIndexes(fromIndex, toIndex, size);
if (fromIndex == toIndex) {
return Collections.emptyList();
}
return new ByteArrayAsList(array, start + fromIndex, start + toIndex);
}
@Override public boolean equals(Object object) {
if (object == this) {
return true;
}
if (object instanceof ByteArrayAsList) {
ByteArrayAsList that = (ByteArrayAsList) 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 + Bytes.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();
}
byte[] toByteArray() {
// Arrays.copyOfRange() requires Java 6
int size = size();
byte[] result = new byte[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 java.io.Serializable;
import java.util.AbstractList;
import java.util.Arrays;
import java.util.BitSet;
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 boolean} primitives, that are not
* already found in either {@link Boolean} 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 Booleans {
private Booleans() {}
/**
* Returns a hash code for {@code value}; equal to the result of invoking
* {@code ((Boolean) value).hashCode()}.
*
* @param value a primitive {@code boolean} value
* @return a hash code for the value
*/
public static int hashCode(boolean value) {
return value ? 1231 : 1237;
}
/**
* Compares the two specified {@code boolean} values in the standard way
* ({@code false} is considered less than {@code true}). The sign of the
* value returned is the same as that of {@code ((Boolean) a).compareTo(b)}.
*
* @param a the first {@code boolean} to compare
* @param b the second {@code boolean} to compare
* @return a positive number if only {@code a} is {@code true}, a negative
* number if only {@code b} is true, or zero if {@code a == b}
*/
public static int compare(boolean a, boolean b) {
return (a == b) ? 0 : (a ? 1 : -1);
}
/**
* Returns {@code true} if {@code target} is present as an element anywhere in
* {@code array}.
*
* <p><b>Note:</b> consider representing the array as a {@link
* BitSet} instead, replacing {@code Booleans.contains(array, true)}
* with {@code !bitSet.isEmpty()} and {@code Booleans.contains(array, false)}
* with {@code bitSet.nextClearBit(0) == sizeOfBitSet}.
*
* @param array an array of {@code boolean} values, possibly empty
* @param target a primitive {@code boolean} value
* @return {@code true} if {@code array[i] == target} for some value of {@code
* i}
*/
public static boolean contains(boolean[] array, boolean target) {
for (boolean value : array) {
if (value == target) {
return true;
}
}
return false;
}
/**
* Returns the index of the first appearance of the value {@code target} in
* {@code array}.
*
* <p><b>Note:</b> consider representing the array as a {@link BitSet}
* instead, and using {@link BitSet#nextSetBit(int)} or {@link
* BitSet#nextClearBit(int)}.
*
* @param array an array of {@code boolean} values, possibly empty
* @param target a primitive {@code boolean} 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(boolean[] array, boolean target) {
return indexOf(array, target, 0, array.length);
}
// TODO(kevinb): consider making this public
private static int indexOf(
boolean[] array, boolean 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(boolean[] array, boolean[] 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 boolean} values, possibly empty
* @param target a primitive {@code boolean} 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(boolean[] array, boolean target) {
return lastIndexOf(array, target, 0, array.length);
}
// TODO(kevinb): consider making this public
private static int lastIndexOf(
boolean[] array, boolean target, int start, int end) {
for (int i = end - 1; i >= start; i--) {
if (array[i] == target) {
return i;
}
}
return -1;
}
/**
* Returns the values from each provided array combined into a single array.
* For example, {@code concat(new boolean[] {a, b}, new boolean[] {}, new
* boolean[] {c}} returns the array {@code {a, b, c}}.
*
* @param arrays zero or more {@code boolean} arrays
* @return a single array containing all the values from the source arrays, in
* order
*/
public static boolean[] concat(boolean[]... arrays) {
int length = 0;
for (boolean[] array : arrays) {
length += array.length;
}
boolean[] result = new boolean[length];
int pos = 0;
for (boolean[] 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 boolean[] ensureCapacity(
boolean[] 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 boolean[] copyOf(boolean[] original, int length) {
boolean[] copy = new boolean[length];
System.arraycopy(original, 0, copy, 0, Math.min(original.length, length));
return copy;
}
/**
* Returns a string containing the supplied {@code boolean} values separated
* by {@code separator}. For example, {@code join("-", false, true, false)}
* returns the string {@code "false-true-false"}.
*
* @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 boolean} values, possibly empty
*/
public static String join(String separator, boolean... 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 * 7);
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 boolean} arrays
* lexicographically. That is, it compares, using {@link
* #compare(boolean, boolean)}), 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 [] < [false] < [false, true] < [true]}.
*
* <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(boolean[], boolean[])}.
*
* @see <a href="http://en.wikipedia.org/wiki/Lexicographical_order">
* Lexicographical order article at Wikipedia</a>
* @since 2.0
*/
public static Comparator<boolean[]> lexicographicalComparator() {
return LexicographicalComparator.INSTANCE;
}
private enum LexicographicalComparator implements Comparator<boolean[]> {
INSTANCE;
@Override
public int compare(boolean[] left, boolean[] right) {
int minLength = Math.min(left.length, right.length);
for (int i = 0; i < minLength; i++) {
int result = Booleans.compare(left[i], right[i]);
if (result != 0) {
return result;
}
}
return left.length - right.length;
}
}
/**
* Copies a collection of {@code Boolean} instances into a new array of
* primitive {@code boolean} 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.
*
* <p><b>Note:</b> consider representing the collection as a {@link
* BitSet} instead.
*
* @param collection a collection of {@code Boolean} 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 boolean[] toArray(Collection<Boolean> collection) {
if (collection instanceof BooleanArrayAsList) {
return ((BooleanArrayAsList) collection).toBooleanArray();
}
Object[] boxedArray = collection.toArray();
int len = boxedArray.length;
boolean[] array = new boolean[len];
for (int i = 0; i < len; i++) {
// checkNotNull for GWT (do not optimize)
array[i] = (Boolean) 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 Boolean} 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<Boolean> asList(boolean... backingArray) {
if (backingArray.length == 0) {
return Collections.emptyList();
}
return new BooleanArrayAsList(backingArray);
}
@GwtCompatible
private static class BooleanArrayAsList extends AbstractList<Boolean>
implements RandomAccess, Serializable {
final boolean[] array;
final int start;
final int end;
BooleanArrayAsList(boolean[] array) {
this(array, 0, array.length);
}
BooleanArrayAsList(boolean[] 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 Boolean 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 Boolean)
&& Booleans.indexOf(array, (Boolean) target, start, end) != -1;
}
@Override public int indexOf(Object target) {
// Overridden to prevent a ton of boxing
if (target instanceof Boolean) {
int i = Booleans.indexOf(array, (Boolean) 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 Boolean) {
int i = Booleans.lastIndexOf(array, (Boolean) target, start, end);
if (i >= 0) {
return i - start;
}
}
return -1;
}
@Override public Boolean set(int index, Boolean element) {
checkElementIndex(index, size());
boolean oldValue = array[start + index];
array[start + index] = checkNotNull(element); // checkNotNull for GWT (do not optimize)
return oldValue;
}
@Override public List<Boolean> subList(int fromIndex, int toIndex) {
int size = size();
checkPositionIndexes(fromIndex, toIndex, size);
if (fromIndex == toIndex) {
return Collections.emptyList();
}
return new BooleanArrayAsList(array, start + fromIndex, start + toIndex);
}
@Override public boolean equals(Object object) {
if (object == this) {
return true;
}
if (object instanceof BooleanArrayAsList) {
BooleanArrayAsList that = (BooleanArrayAsList) 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 + Booleans.hashCode(array[i]);
}
return result;
}
@Override public String toString() {
StringBuilder builder = new StringBuilder(size() * 7);
builder.append(array[start] ? "[true" : "[false");
for (int i = start + 1; i < end; i++) {
builder.append(array[i] ? ", true" : ", false");
}
return builder.append(']').toString();
}
boolean[] toBooleanArray() {
// Arrays.copyOfRange() requires Java 6
int size = size();
boolean[] result = new boolean[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.io.Serializable;
import java.math.BigInteger;
import javax.annotation.Nullable;
import com.google.common.annotations.Beta;
import com.google.common.annotations.GwtCompatible;
/**
* A wrapper class for unsigned {@code long} 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 long} values as unsigned, using the methods from {@link UnsignedLongs}.
*
* <p><b>Please do not extend this class; it will be made final in the near future.</b>
*
* <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 Colin Evans
* @since 11.0
*/
@Beta
@GwtCompatible(serializable = true)
public class UnsignedLong extends Number implements Comparable<UnsignedLong>, Serializable {
// TODO(user): make final as soon as util.UnsignedLong is migrated over
private static final long UNSIGNED_MASK = 0x7fffffffffffffffL;
public static final UnsignedLong ZERO = new UnsignedLong(0);
public static final UnsignedLong ONE = new UnsignedLong(1);
public static final UnsignedLong MAX_VALUE = new UnsignedLong(-1L);
private final long value;
protected UnsignedLong(long value) {
this.value = value;
}
/**
* Returns an {@code UnsignedLong} that, when treated as signed, is equal to {@code value}. The
* inverse operation is {@link #longValue()}.
*
* <p>Put another way, if {@code value} is negative, the returned result will be equal to
* {@code 2^64 + value}; otherwise, the returned result will be equal to {@code value}.
*/
public static UnsignedLong asUnsigned(long value) {
return new UnsignedLong(value);
}
/**
* Returns a {@code UnsignedLong} representing the same value as the specified {@code BigInteger}
* . This is the inverse operation of {@link #bigIntegerValue()}.
*
* @throws IllegalArgumentException if {@code value} is negative or {@code value >= 2^64}
*/
public static UnsignedLong valueOf(BigInteger value) {
checkNotNull(value);
checkArgument(value.signum() >= 0 && value.bitLength() <= Long.SIZE,
"value (%s) is outside the range for an unsigned long value", value);
return asUnsigned(value.longValue());
}
/**
* Returns an {@code UnsignedLong} holding the value of the specified {@code String}, parsed as
* an unsigned {@code long} value.
*
* @throws NumberFormatException if the string does not contain a parsable unsigned {@code long}
* value
*/
public static UnsignedLong valueOf(String string) {
return valueOf(string, 10);
}
/**
* Returns an {@code UnsignedLong} holding the value of the specified {@code String}, parsed as
* an unsigned {@code long} value in the specified radix.
*
* @throws NumberFormatException if the string does not contain a parsable unsigned {@code long}
* value, or {@code radix} is not between {@link Character#MIN_RADIX} and
* {@link Character#MAX_RADIX}
*/
public static UnsignedLong valueOf(String string, int radix) {
return asUnsigned(UnsignedLongs.parseUnsignedLong(string, radix));
}
/**
* Returns the result of adding this and {@code val}. If the result would have more than 64 bits,
* returns the low 64 bits of the result.
*/
public UnsignedLong add(UnsignedLong 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 64 bits of the result.
*/
public UnsignedLong subtract(UnsignedLong 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 64
* bits, returns the low 64 bits of the result.
*/
public UnsignedLong multiply(UnsignedLong val) {
checkNotNull(val);
return asUnsigned(value * val.value);
}
/**
* Returns the result of dividing this by {@code val}.
*/
public UnsignedLong divide(UnsignedLong val) {
checkNotNull(val);
return asUnsigned(UnsignedLongs.divide(value, val.value));
}
/**
* Returns the remainder of dividing this by {@code val}.
*/
public UnsignedLong remainder(UnsignedLong val) {
checkNotNull(val);
return asUnsigned(UnsignedLongs.remainder(value, val.value));
}
/**
* Returns the value of this {@code UnsignedLong} as an {@code int}.
*/
@Override
public int intValue() {
return (int) value;
}
/**
* Returns the value of this {@code UnsignedLong} as a {@code long}. This is an inverse operation
* to {@link #asUnsigned}.
*
* <p>Note that if this {@code UnsignedLong} holds a value {@code >= 2^63}, the returned value
* will be equal to {@code this - 2^64}.
*/
@Override
public long longValue() {
return value;
}
/**
* Returns the value of this {@code UnsignedLong} as a {@code float}, analogous to a widening
* primitive conversion from {@code long} to {@code float}, and correctly rounded.
*/
@Override
public float floatValue() {
@SuppressWarnings("cast")
float fValue = (float) (value & UNSIGNED_MASK);
if (value < 0) {
fValue += 0x1.0p63f;
}
return fValue;
}
/**
* Returns the value of this {@code UnsignedLong} as a {@code double}, analogous to a widening
* primitive conversion from {@code long} to {@code double}, and correctly rounded.
*/
@Override
public double doubleValue() {
@SuppressWarnings("cast")
double dValue = (double) (value & UNSIGNED_MASK);
if (value < 0) {
dValue += 0x1.0p63;
}
return dValue;
}
/**
* Returns the value of this {@code UnsignedLong} as a {@link BigInteger}.
*/
public BigInteger bigIntegerValue() {
BigInteger bigInt = BigInteger.valueOf(value & UNSIGNED_MASK);
if (value < 0) {
bigInt = bigInt.setBit(Long.SIZE - 1);
}
return bigInt;
}
@Override
public int compareTo(UnsignedLong o) {
checkNotNull(o);
return UnsignedLongs.compare(value, o.value);
}
@Override
public int hashCode() {
return Longs.hashCode(value);
}
@Override
public boolean equals(@Nullable Object obj) {
if (obj instanceof UnsignedLong) {
UnsignedLong other = (UnsignedLong) obj;
return value == other.value;
}
return false;
}
/**
* Returns a string representation of the {@code UnsignedLong} value, in base 10.
*/
@Override
public String toString() {
return UnsignedLongs.toString(value);
}
/**
* Returns a string representation of the {@code UnsignedLong} 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 UnsignedLongs.toString(value, radix);
}
}
| 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.math;
import static com.google.common.base.Preconditions.checkArgument;
import static com.google.common.base.Preconditions.checkNotNull;
import static com.google.common.math.MathPreconditions.checkNonNegative;
import static com.google.common.math.MathPreconditions.checkPositive;
import static com.google.common.math.MathPreconditions.checkRoundingUnnecessary;
import static java.math.RoundingMode.CEILING;
import static java.math.RoundingMode.FLOOR;
import static java.math.RoundingMode.HALF_EVEN;
import com.google.common.annotations.Beta;
import com.google.common.annotations.VisibleForTesting;
import java.math.BigDecimal;
import java.math.BigInteger;
import java.math.RoundingMode;
import java.util.ArrayList;
import java.util.List;
/**
* A class for arithmetic on values of type {@code BigInteger}.
*
* <p>The implementations of many methods in this class are based on material from Henry S. Warren,
* Jr.'s <i>Hacker's Delight</i>, (Addison Wesley, 2002).
*
* <p>Similar functionality for {@code int} and for {@code long} can be found in
* {@link IntMath} and {@link LongMath} respectively.
*
* @author Louis Wasserman
* @since 11.0
*/
@Beta
public final class BigIntegerMath {
/**
* Returns {@code true} if {@code x} represents a power of two.
*/
public static boolean isPowerOfTwo(BigInteger x) {
checkNotNull(x);
return x.signum() > 0 && x.getLowestSetBit() == x.bitLength() - 1;
}
/**
* Returns the base-2 logarithm of {@code x}, rounded according to the specified rounding mode.
*
* @throws IllegalArgumentException if {@code x <= 0}
* @throws ArithmeticException if {@code mode} is {@link RoundingMode#UNNECESSARY} and {@code x}
* is not a power of two
*/
@SuppressWarnings("fallthrough")
public static int log2(BigInteger x, RoundingMode mode) {
checkPositive("x", checkNotNull(x));
int logFloor = x.bitLength() - 1;
switch (mode) {
case UNNECESSARY:
checkRoundingUnnecessary(isPowerOfTwo(x)); // fall through
case DOWN:
case FLOOR:
return logFloor;
case UP:
case CEILING:
return isPowerOfTwo(x) ? logFloor : logFloor + 1;
case HALF_DOWN:
case HALF_UP:
case HALF_EVEN:
if (logFloor < SQRT2_PRECOMPUTE_THRESHOLD) {
BigInteger halfPower = SQRT2_PRECOMPUTED_BITS.shiftRight(
SQRT2_PRECOMPUTE_THRESHOLD - logFloor);
if (x.compareTo(halfPower) <= 0) {
return logFloor;
} else {
return logFloor + 1;
}
}
/*
* Since sqrt(2) is irrational, log2(x) - logFloor cannot be exactly 0.5
*
* To determine which side of logFloor.5 the logarithm is, we compare x^2 to 2^(2 *
* logFloor + 1).
*/
BigInteger x2 = x.pow(2);
int logX2Floor = x2.bitLength() - 1;
return (logX2Floor < 2 * logFloor + 1) ? logFloor : logFloor + 1;
default:
throw new AssertionError();
}
}
/*
* The maximum number of bits in a square root for which we'll precompute an explicit half power
* of two. This can be any value, but higher values incur more class load time and linearly
* increasing memory consumption.
*/
@VisibleForTesting static final int SQRT2_PRECOMPUTE_THRESHOLD = 256;
@VisibleForTesting static final BigInteger SQRT2_PRECOMPUTED_BITS =
new BigInteger("16a09e667f3bcc908b2fb1366ea957d3e3adec17512775099da2f590b0667322a", 16);
/**
* Returns the base-10 logarithm of {@code x}, rounded according to the specified rounding mode.
*
* @throws IllegalArgumentException if {@code x <= 0}
* @throws ArithmeticException if {@code mode} is {@link RoundingMode#UNNECESSARY} and {@code x}
* is not a power of ten
*/
@SuppressWarnings("fallthrough")
public static int log10(BigInteger x, RoundingMode mode) {
checkPositive("x", x);
if (fitsInLong(x)) {
return LongMath.log10(x.longValue(), mode);
}
// capacity of 10 suffices for all x <= 10^(2^10).
List<BigInteger> powersOf10 = new ArrayList<BigInteger>(10);
BigInteger powerOf10 = BigInteger.TEN;
while (x.compareTo(powerOf10) >= 0) {
powersOf10.add(powerOf10);
powerOf10 = powerOf10.pow(2);
}
BigInteger floorPow = BigInteger.ONE;
int floorLog = 0;
for (int i = powersOf10.size() - 1; i >= 0; i--) {
BigInteger powOf10 = powersOf10.get(i);
floorLog *= 2;
BigInteger tenPow = powOf10.multiply(floorPow);
if (x.compareTo(tenPow) >= 0) {
floorPow = tenPow;
floorLog++;
}
}
switch (mode) {
case UNNECESSARY:
checkRoundingUnnecessary(floorPow.equals(x));
// fall through
case FLOOR:
case DOWN:
return floorLog;
case CEILING:
case UP:
return floorPow.equals(x) ? floorLog : floorLog + 1;
case HALF_DOWN:
case HALF_UP:
case HALF_EVEN:
// Since sqrt(10) is irrational, log10(x) - floorLog can never be exactly 0.5
BigInteger x2 = x.pow(2);
BigInteger halfPowerSquared = floorPow.pow(2).multiply(BigInteger.TEN);
return (x2.compareTo(halfPowerSquared) <= 0) ? floorLog : floorLog + 1;
default:
throw new AssertionError();
}
}
/**
* Returns the square root of {@code x}, rounded with the specified rounding mode.
*
* @throws IllegalArgumentException if {@code x < 0}
* @throws ArithmeticException if {@code mode} is {@link RoundingMode#UNNECESSARY} and
* {@code sqrt(x)} is not an integer
*/
@SuppressWarnings("fallthrough")
public static BigInteger sqrt(BigInteger x, RoundingMode mode) {
checkNonNegative("x", x);
if (fitsInLong(x)) {
return BigInteger.valueOf(LongMath.sqrt(x.longValue(), mode));
}
BigInteger sqrtFloor = sqrtFloor(x);
switch (mode) {
case UNNECESSARY:
checkRoundingUnnecessary(sqrtFloor.pow(2).equals(x)); // fall through
case FLOOR:
case DOWN:
return sqrtFloor;
case CEILING:
case UP:
return sqrtFloor.pow(2).equals(x) ? sqrtFloor : sqrtFloor.add(BigInteger.ONE);
case HALF_DOWN:
case HALF_UP:
case HALF_EVEN:
BigInteger halfSquare = sqrtFloor.pow(2).add(sqrtFloor);
/*
* We wish to test whether or not x <= (sqrtFloor + 0.5)^2 = halfSquare + 0.25. Since both
* x and halfSquare are integers, this is equivalent to testing whether or not x <=
* halfSquare.
*/
return (halfSquare.compareTo(x) >= 0) ? sqrtFloor : sqrtFloor.add(BigInteger.ONE);
default:
throw new AssertionError();
}
}
private static BigInteger sqrtFloor(BigInteger x) {
/*
* Adapted from Hacker's Delight, Figure 11-1.
*
* Using DoubleUtils.bigToDouble, getting a double approximation of x is extremely fast, and
* then we can get a double approximation of the square root. Then, we iteratively improve this
* guess with an application of Newton's method, which sets guess := (guess + (x / guess)) / 2.
* This iteration has the following two properties:
*
* a) every iteration (except potentially the first) has guess >= floor(sqrt(x)). This is
* because guess' is the arithmetic mean of guess and x / guess, sqrt(x) is the geometric mean,
* and the arithmetic mean is always higher than the geometric mean.
*
* b) this iteration converges to floor(sqrt(x)). In fact, the number of correct digits doubles
* with each iteration, so this algorithm takes O(log(digits)) iterations.
*
* We start out with a double-precision approximation, which may be higher or lower than the
* true value. Therefore, we perform at least one Newton iteration to get a guess that's
* definitely >= floor(sqrt(x)), and then continue the iteration until we reach a fixed point.
*/
BigInteger sqrt0;
int log2 = log2(x, FLOOR);
if(log2 < Double.MAX_EXPONENT) {
sqrt0 = sqrtApproxWithDoubles(x);
} else {
int shift = (log2 - DoubleUtils.SIGNIFICAND_BITS) & ~1; // even!
/*
* We have that x / 2^shift < 2^54. Our initial approximation to sqrtFloor(x) will be
* 2^(shift/2) * sqrtApproxWithDoubles(x / 2^shift).
*/
sqrt0 = sqrtApproxWithDoubles(x.shiftRight(shift)).shiftLeft(shift >> 1);
}
BigInteger sqrt1 = sqrt0.add(x.divide(sqrt0)).shiftRight(1);
if (sqrt0.equals(sqrt1)) {
return sqrt0;
}
do {
sqrt0 = sqrt1;
sqrt1 = sqrt0.add(x.divide(sqrt0)).shiftRight(1);
} while (sqrt1.compareTo(sqrt0) < 0);
return sqrt0;
}
private static BigInteger sqrtApproxWithDoubles(BigInteger x) {
return DoubleMath.roundToBigInteger(Math.sqrt(DoubleUtils.bigToDouble(x)), HALF_EVEN);
}
/**
* Returns the result of dividing {@code p} by {@code q}, rounding using the specified
* {@code RoundingMode}.
*
* @throws ArithmeticException if {@code q == 0}, or if {@code mode == UNNECESSARY} and {@code a}
* is not an integer multiple of {@code b}
*/
public static BigInteger divide(BigInteger p, BigInteger q, RoundingMode mode){
BigDecimal pDec = new BigDecimal(p);
BigDecimal qDec = new BigDecimal(q);
return pDec.divide(qDec, 0, mode).toBigIntegerExact();
}
/**
* Returns {@code n!}, that is, the product of the first {@code n} positive
* integers, or {@code 1} if {@code n == 0}.
*
* <p><b>Warning</b>: the result takes <i>O(n log n)</i> space, so use cautiously.
*
* <p>This uses an efficient binary recursive algorithm to compute the factorial
* with balanced multiplies. It also removes all the 2s from the intermediate
* products (shifting them back in at the end).
*
* @throws IllegalArgumentException if {@code n < 0}
*/
public static BigInteger factorial(int n) {
checkNonNegative("n", n);
// If the factorial is small enough, just use LongMath to do it.
if (n < LongMath.FACTORIALS.length) {
return BigInteger.valueOf(LongMath.FACTORIALS[n]);
}
// Pre-allocate space for our list of intermediate BigIntegers.
int approxSize = IntMath.divide(n * IntMath.log2(n, CEILING), Long.SIZE, CEILING);
ArrayList<BigInteger> bignums = new ArrayList<BigInteger>(approxSize);
// Start from the pre-computed maximum long factorial.
int startingNumber = LongMath.FACTORIALS.length;
long product = LongMath.FACTORIALS[startingNumber - 1];
// Strip off 2s from this value.
int shift = Long.numberOfTrailingZeros(product);
product >>= shift;
// Use floor(log2(num)) + 1 to prevent overflow of multiplication.
int productBits = LongMath.log2(product, FLOOR) + 1;
int bits = LongMath.log2(startingNumber, FLOOR) + 1;
// Check for the next power of two boundary, to save us a CLZ operation.
int nextPowerOfTwo = 1 << (bits - 1);
// Iteratively multiply the longs as big as they can go.
for (long num = startingNumber; num <= n; num++) {
// Check to see if the floor(log2(num)) + 1 has changed.
if ((num & nextPowerOfTwo) != 0) {
nextPowerOfTwo <<= 1;
bits++;
}
// Get rid of the 2s in num.
int tz = Long.numberOfTrailingZeros(num);
long normalizedNum = num >> tz;
shift += tz;
// Adjust floor(log2(num)) + 1.
int normalizedBits = bits - tz;
// If it won't fit in a long, then we store off the intermediate product.
if (normalizedBits + productBits >= Long.SIZE) {
bignums.add(BigInteger.valueOf(product));
product = 1;
productBits = 0;
}
product *= normalizedNum;
productBits = LongMath.log2(product, FLOOR) + 1;
}
// Check for leftovers.
if (product > 1) {
bignums.add(BigInteger.valueOf(product));
}
// Efficiently multiply all the intermediate products together.
return listProduct(bignums).shiftLeft(shift);
}
static BigInteger listProduct(List<BigInteger> nums) {
return listProduct(nums, 0, nums.size());
}
static BigInteger listProduct(List<BigInteger> nums, int start, int end) {
switch (end - start) {
case 0:
return BigInteger.ONE;
case 1:
return nums.get(start);
case 2:
return nums.get(start).multiply(nums.get(start + 1));
case 3:
return nums.get(start).multiply(nums.get(start + 1)).multiply(nums.get(start + 2));
default:
// Otherwise, split the list in half and recursively do this.
int m = (end + start) >>> 1;
return listProduct(nums, start, m).multiply(listProduct(nums, m, end));
}
}
/**
* Returns {@code n} choose {@code k}, also known as the binomial coefficient of {@code n} and
* {@code k}, that is, {@code n! / (k! (n - k)!)}.
*
* <p><b>Warning</b>: the result can take as much as <i>O(k log n)</i> space.
*
* @throws IllegalArgumentException if {@code n < 0}, {@code k < 0}, or {@code k > n}
*/
public static BigInteger binomial(int n, int k) {
checkNonNegative("n", n);
checkNonNegative("k", k);
checkArgument(k <= n, "k (%s) > n (%s)", k, n);
if (k > (n >> 1)) {
k = n - k;
}
if (k < LongMath.BIGGEST_BINOMIALS.length && n <= LongMath.BIGGEST_BINOMIALS[k]) {
return BigInteger.valueOf(LongMath.binomial(n, k));
}
BigInteger result = BigInteger.ONE;
for (int i = 0; i < k; i++) {
result = result.multiply(BigInteger.valueOf(n - i));
result = result.divide(BigInteger.valueOf(i + 1));
}
return result;
}
// Returns true if BigInteger.valueOf(x.longValue()).equals(x).
static boolean fitsInLong(BigInteger x) {
return x.bitLength() <= Long.SIZE - 1;
}
private BigIntegerMath() {}
}
| 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.math;
import static com.google.common.base.Preconditions.checkArgument;
import static com.google.common.math.DoubleUtils.IMPLICIT_BIT;
import static com.google.common.math.DoubleUtils.SIGNIFICAND_BITS;
import static com.google.common.math.DoubleUtils.getSignificand;
import static com.google.common.math.DoubleUtils.isFinite;
import static com.google.common.math.DoubleUtils.isNormal;
import static com.google.common.math.DoubleUtils.scaleNormalize;
import static com.google.common.math.MathPreconditions.checkInRange;
import static com.google.common.math.MathPreconditions.checkNonNegative;
import static com.google.common.math.MathPreconditions.checkRoundingUnnecessary;
import com.google.common.annotations.Beta;
import com.google.common.annotations.VisibleForTesting;
import java.math.BigInteger;
import java.math.RoundingMode;
/**
* A class for arithmetic on doubles that is not covered by {@link java.lang.Math}.
*
* @author Louis Wasserman
* @since 11.0
*/
@Beta
public final class DoubleMath {
/*
* This method returns a value y such that rounding y DOWN (towards zero) gives the same result
* as rounding x according to the specified mode.
*/
static double roundIntermediate(double x, RoundingMode mode) {
if (!isFinite(x)) {
throw new ArithmeticException("input is infinite or NaN");
}
switch (mode) {
case UNNECESSARY:
checkRoundingUnnecessary(isMathematicalInteger(x));
return x;
case FLOOR:
return (x >= 0.0) ? x : Math.floor(x);
case CEILING:
return (x >= 0.0) ? Math.ceil(x) : x;
case DOWN:
return x;
case UP:
return (x >= 0.0) ? Math.ceil(x) : Math.floor(x);
case HALF_EVEN:
return Math.rint(x);
case HALF_UP:
if (isMathematicalInteger(x)) {
return x;
} else {
return (x >= 0.0) ? x + 0.5 : x - 0.5;
}
case HALF_DOWN:
if (isMathematicalInteger(x)) {
return x;
} else if (x >= 0.0) {
double z = x + 0.5;
return (z == x) ? x : DoubleUtils.nextDown(z); // x + 0.5 - epsilon
} else {
double z = x - 0.5;
return (z == x) ? x : Math.nextUp(z); // x - 0.5 + epsilon
}
default:
throw new AssertionError();
}
}
/**
* Returns the {@code int} value that is equal to {@code x} rounded with the specified rounding
* mode, if possible.
*
* @throws ArithmeticException if
* <ul>
* <li>{@code x} is infinite or NaN
* <li>{@code x}, after being rounded to a mathematical integer using the specified
* rounding mode, is either less than {@code Integer.MIN_VALUE} or greater than {@code
* Integer.MAX_VALUE}
* <li>{@code x} is not a mathematical integer and {@code mode} is
* {@link RoundingMode#UNNECESSARY}
* </ul>
*/
public static int roundToInt(double x, RoundingMode mode) {
double z = roundIntermediate(x, mode);
checkInRange(z > MIN_INT_AS_DOUBLE - 1.0 & z < MAX_INT_AS_DOUBLE + 1.0);
return (int) z;
}
private static final double MIN_INT_AS_DOUBLE = -0x1p31;
private static final double MAX_INT_AS_DOUBLE = 0x1p31 - 1.0;
/**
* Returns the {@code long} value that is equal to {@code x} rounded with the specified rounding
* mode, if possible.
*
* @throws ArithmeticException if
* <ul>
* <li>{@code x} is infinite or NaN
* <li>{@code x}, after being rounded to a mathematical integer using the specified
* rounding mode, is either less than {@code Long.MIN_VALUE} or greater than {@code
* Long.MAX_VALUE}
* <li>{@code x} is not a mathematical integer and {@code mode} is
* {@link RoundingMode#UNNECESSARY}
* </ul>
*/
public static long roundToLong(double x, RoundingMode mode) {
double z = roundIntermediate(x, mode);
checkInRange(MIN_LONG_AS_DOUBLE - z < 1.0 & z < MAX_LONG_AS_DOUBLE_PLUS_ONE);
return (long) z;
}
private static final double MIN_LONG_AS_DOUBLE = -0x1p63;
/*
* We cannot store Long.MAX_VALUE as a double without losing precision. Instead, we store
* Long.MAX_VALUE + 1 == -Long.MIN_VALUE, and then offset all comparisons by 1.
*/
private static final double MAX_LONG_AS_DOUBLE_PLUS_ONE = 0x1p63;
/**
* Returns the {@code BigInteger} value that is equal to {@code x} rounded with the specified
* rounding mode, if possible.
*
* @throws ArithmeticException if
* <ul>
* <li>{@code x} is infinite or NaN
* <li>{@code x} is not a mathematical integer and {@code mode} is
* {@link RoundingMode#UNNECESSARY}
* </ul>
*/
public static BigInteger roundToBigInteger(double x, RoundingMode mode) {
x = roundIntermediate(x, mode);
if (MIN_LONG_AS_DOUBLE - x < 1.0 & x < MAX_LONG_AS_DOUBLE_PLUS_ONE) {
return BigInteger.valueOf((long) x);
}
int exponent = Math.getExponent(x);
if (exponent < 0) {
return BigInteger.ZERO;
}
long significand = getSignificand(x);
BigInteger result = BigInteger.valueOf(significand).shiftLeft(exponent - SIGNIFICAND_BITS);
return (x < 0) ? result.negate() : result;
}
/**
* Returns {@code true} if {@code x} is exactly equal to {@code 2^k} for some finite integer
* {@code k}.
*/
public static boolean isPowerOfTwo(double x) {
return x > 0.0 && isFinite(x) && LongMath.isPowerOfTwo(getSignificand(x));
}
/**
* Returns the base 2 logarithm of a double value.
*
* <p>Special cases:
* <ul>
* <li>If {@code x} is NaN or less than zero, the result is NaN.
* <li>If {@code x} is positive infinity, the result is positive infinity.
* <li>If {@code x} is positive or negative zero, the result is negative infinity.
* </ul>
*
* <p>The computed result must be within 1 ulp of the exact result.
*
* <p>If the result of this method will be immediately rounded to an {@code int},
* {@link #log2(double, RoundingMode)} is faster.
*/
public static double log2(double x) {
return Math.log(x) / LN_2; // surprisingly within 1 ulp according to tests
}
private static final double LN_2 = Math.log(2);
/**
* Returns the base 2 logarithm of a double value, rounded with the specified rounding mode to an
* {@code int}.
*
* <p>Regardless of the rounding mode, this is faster than {@code (int) log2(x)}.
*
* @throws IllegalArgumentException if {@code x <= 0.0}, {@code x} is NaN, or {@code x} is
* infinite
*/
@SuppressWarnings("fallthrough")
public static int log2(double x, RoundingMode mode) {
checkArgument(x > 0.0 && isFinite(x), "x must be positive and finite");
int exponent = Math.getExponent(x);
if (!isNormal(x)) {
return log2(x * IMPLICIT_BIT, mode) - SIGNIFICAND_BITS;
// Do the calculation on a normal value.
}
// x is positive, finite, and normal
boolean increment;
switch (mode) {
case UNNECESSARY:
checkRoundingUnnecessary(isPowerOfTwo(x));
// fall through
case FLOOR:
increment = false;
break;
case CEILING:
increment = !isPowerOfTwo(x);
break;
case DOWN:
increment = exponent < 0 & !isPowerOfTwo(x);
break;
case UP:
increment = exponent >= 0 & !isPowerOfTwo(x);
break;
case HALF_DOWN:
case HALF_EVEN:
case HALF_UP:
double xScaled = scaleNormalize(x);
// sqrt(2) is irrational, and the spec is relative to the "exact numerical result,"
// so log2(x) is never exactly exponent + 0.5.
increment = (xScaled * xScaled) > 2.0;
break;
default:
throw new AssertionError();
}
return increment ? exponent + 1 : exponent;
}
/**
* Returns {@code true} if {@code x} represents a mathematical integer.
*
* <p>This is equivalent to, but not necessarily implemented as, the expression {@code
* !Double.isNaN(x) && !Double.isInfinite(x) && x == Math.rint(x)}.
*/
public static boolean isMathematicalInteger(double x) {
return isFinite(x)
&& (x == 0.0 || SIGNIFICAND_BITS
- Long.numberOfTrailingZeros(getSignificand(x)) <= Math.getExponent(x));
}
/**
* Returns {@code n!}, that is, the product of the first {@code n} positive
* integers, {@code 1} if {@code n == 0}, or e n!}, or
* {@link Double#POSITIVE_INFINITY} if {@code n! > Double.MAX_VALUE}.
*
* <p>The result is within 1 ulp of the true value.
*
* @throws IllegalArgumentException if {@code n < 0}
*/
public static double factorial(int n) {
checkNonNegative("n", n);
if (n > MAX_FACTORIAL) {
return Double.POSITIVE_INFINITY;
} else {
// Multiplying the last (n & 0xf) values into their own accumulator gives a more accurate
// result than multiplying by EVERY_SIXTEENTH_FACTORIAL[n >> 4] directly.
double accum = 1.0;
for (int i = 1 + (n & ~0xf); i <= n; i++) {
accum *= i;
}
return accum * EVERY_SIXTEENTH_FACTORIAL[n >> 4];
}
}
@VisibleForTesting
static final int MAX_FACTORIAL = 170;
@VisibleForTesting
static final double[] EVERY_SIXTEENTH_FACTORIAL = {
0x1.0p0,
0x1.30777758p44,
0x1.956ad0aae33a4p117,
0x1.ee69a78d72cb6p202,
0x1.fe478ee34844ap295,
0x1.c619094edabffp394,
0x1.3638dd7bd6347p498,
0x1.7cac197cfe503p605,
0x1.1e5dfc140e1e5p716,
0x1.8ce85fadb707ep829,
0x1.95d5f3d928edep945};
}
| 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.
*/
/**
* Arithmetic functions operating on primitive values and {@link java.math.BigInteger} instances.
*
* <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/MathExplained">
* math utilities</a>.
*/
@ParametersAreNonnullByDefault
package com.google.common.math;
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.math;
import static com.google.common.base.Preconditions.checkArgument;
import static com.google.common.base.Preconditions.checkNotNull;
import static com.google.common.math.MathPreconditions.checkNoOverflow;
import static com.google.common.math.MathPreconditions.checkNonNegative;
import static com.google.common.math.MathPreconditions.checkPositive;
import static com.google.common.math.MathPreconditions.checkRoundingUnnecessary;
import static java.lang.Math.abs;
import static java.lang.Math.min;
import static java.math.RoundingMode.HALF_EVEN;
import static java.math.RoundingMode.HALF_UP;
import com.google.common.annotations.Beta;
import com.google.common.annotations.VisibleForTesting;
import java.math.BigInteger;
import java.math.RoundingMode;
/**
* A class for arithmetic on values of type {@code long}. Where possible, methods are defined and
* named analogously to their {@code BigInteger} counterparts.
*
* <p>The implementations of many methods in this class are based on material from Henry S. Warren,
* Jr.'s <i>Hacker's Delight</i>, (Addison Wesley, 2002).
*
* <p>Similar functionality for {@code int} and for {@link BigInteger} can be found in
* {@link IntMath} and {@link BigIntegerMath} respectively. For other common operations on
* {@code long} values, see {@link com.google.common.primitives.Longs}.
*
* @author Louis Wasserman
* @since 11.0
*/
@Beta
public final class LongMath {
// NOTE: Whenever both tests are cheap and functional, it's faster to use &, | instead of &&, ||
/**
* Returns {@code true} if {@code x} represents a power of two.
*
* <p>This differs from {@code Long.bitCount(x) == 1}, because
* {@code Long.bitCount(Long.MIN_VALUE) == 1}, but {@link Long#MIN_VALUE} is not a power of two.
*/
public static boolean isPowerOfTwo(long x) {
return x > 0 & (x & (x - 1)) == 0;
}
/**
* Returns the base-2 logarithm of {@code x}, rounded according to the specified rounding mode.
*
* @throws IllegalArgumentException if {@code x <= 0}
* @throws ArithmeticException if {@code mode} is {@link RoundingMode#UNNECESSARY} and {@code x}
* is not a power of two
*/
@SuppressWarnings("fallthrough")
public static int log2(long x, RoundingMode mode) {
checkPositive("x", x);
switch (mode) {
case UNNECESSARY:
checkRoundingUnnecessary(isPowerOfTwo(x));
// fall through
case DOWN:
case FLOOR:
return (Long.SIZE - 1) - Long.numberOfLeadingZeros(x);
case UP:
case CEILING:
return Long.SIZE - Long.numberOfLeadingZeros(x - 1);
case HALF_DOWN:
case HALF_UP:
case HALF_EVEN:
// Since sqrt(2) is irrational, log2(x) - logFloor cannot be exactly 0.5
int leadingZeros = Long.numberOfLeadingZeros(x);
long cmp = MAX_POWER_OF_SQRT2_UNSIGNED >>> leadingZeros;
// floor(2^(logFloor + 0.5))
int logFloor = (Long.SIZE - 1) - leadingZeros;
return (x <= cmp) ? logFloor : logFloor + 1;
default:
throw new AssertionError("impossible");
}
}
/** The biggest half power of two that fits into an unsigned long */
@VisibleForTesting static final long MAX_POWER_OF_SQRT2_UNSIGNED = 0xB504F333F9DE6484L;
/**
* Returns the base-10 logarithm of {@code x}, rounded according to the specified rounding mode.
*
* @throws IllegalArgumentException if {@code x <= 0}
* @throws ArithmeticException if {@code mode} is {@link RoundingMode#UNNECESSARY} and {@code x}
* is not a power of ten
*/
@SuppressWarnings("fallthrough")
public static int log10(long x, RoundingMode mode) {
checkPositive("x", x);
if (fitsInInt(x)) {
return IntMath.log10((int) x, mode);
}
int logFloor = log10Floor(x);
long floorPow = POWERS_OF_10[logFloor];
switch (mode) {
case UNNECESSARY:
checkRoundingUnnecessary(x == floorPow);
// fall through
case FLOOR:
case DOWN:
return logFloor;
case CEILING:
case UP:
return (x == floorPow) ? logFloor : logFloor + 1;
case HALF_DOWN:
case HALF_UP:
case HALF_EVEN:
// sqrt(10) is irrational, so log10(x)-logFloor is never exactly 0.5
return (x <= HALF_POWERS_OF_10[logFloor]) ? logFloor : logFloor + 1;
default:
throw new AssertionError();
}
}
static int log10Floor(long x) {
for (int i = 1; i < POWERS_OF_10.length; i++) {
if (x < POWERS_OF_10[i]) {
return i - 1;
}
}
return POWERS_OF_10.length - 1;
}
@VisibleForTesting
static final long[] POWERS_OF_10 = {
1L,
10L,
100L,
1000L,
10000L,
100000L,
1000000L,
10000000L,
100000000L,
1000000000L,
10000000000L,
100000000000L,
1000000000000L,
10000000000000L,
100000000000000L,
1000000000000000L,
10000000000000000L,
100000000000000000L,
1000000000000000000L
};
// HALF_POWERS_OF_10[i] = largest long less than 10^(i + 0.5)
@VisibleForTesting
static final long[] HALF_POWERS_OF_10 = {
3L,
31L,
316L,
3162L,
31622L,
316227L,
3162277L,
31622776L,
316227766L,
3162277660L,
31622776601L,
316227766016L,
3162277660168L,
31622776601683L,
316227766016837L,
3162277660168379L,
31622776601683793L,
316227766016837933L,
3162277660168379331L
};
/**
* Returns {@code b} to the {@code k}th power. Even if the result overflows, it will be equal to
* {@code BigInteger.valueOf(b).pow(k).longValue()}. This implementation runs in {@code O(log k)}
* time.
*
* @throws IllegalArgumentException if {@code k < 0}
*/
public static long pow(long b, int k) {
checkNonNegative("exponent", k);
if (-2 <= b && b <= 2) {
switch ((int) b) {
case 0:
return (k == 0) ? 1 : 0;
case 1:
return 1;
case (-1):
return ((k & 1) == 0) ? 1 : -1;
case 2:
return (k < Long.SIZE) ? 1L << k : 0;
case (-2):
if (k < Long.SIZE) {
return ((k & 1) == 0) ? 1L << k : -(1L << k);
} else {
return 0;
}
}
}
for (long accum = 1;; k >>= 1) {
switch (k) {
case 0:
return accum;
case 1:
return accum * b;
default:
accum *= ((k & 1) == 0) ? 1 : b;
b *= b;
}
}
}
/**
* Returns the square root of {@code x}, rounded with the specified rounding mode.
*
* @throws IllegalArgumentException if {@code x < 0}
* @throws ArithmeticException if {@code mode} is {@link RoundingMode#UNNECESSARY} and
* {@code sqrt(x)} is not an integer
*/
@SuppressWarnings("fallthrough")
public static long sqrt(long x, RoundingMode mode) {
checkNonNegative("x", x);
if (fitsInInt(x)) {
return IntMath.sqrt((int) x, mode);
}
long sqrtFloor = sqrtFloor(x);
switch (mode) {
case UNNECESSARY:
checkRoundingUnnecessary(sqrtFloor * sqrtFloor == x); // fall through
case FLOOR:
case DOWN:
return sqrtFloor;
case CEILING:
case UP:
return (sqrtFloor * sqrtFloor == x) ? sqrtFloor : sqrtFloor + 1;
case HALF_DOWN:
case HALF_UP:
case HALF_EVEN:
long halfSquare = sqrtFloor * sqrtFloor + sqrtFloor;
/*
* We wish to test whether or not x <= (sqrtFloor + 0.5)^2 = halfSquare + 0.25. Since both
* x and halfSquare are integers, this is equivalent to testing whether or not x <=
* halfSquare. (We have to deal with overflow, though.)
*/
return (halfSquare >= x | halfSquare < 0) ? sqrtFloor : sqrtFloor + 1;
default:
throw new AssertionError();
}
}
private static long sqrtFloor(long x) {
// Hackers's Delight, Figure 11-1
long sqrt0 = (long) Math.sqrt(x);
// Precision can be lost in the cast to double, so we use this as a starting estimate.
long sqrt1 = (sqrt0 + (x / sqrt0)) >> 1;
if (sqrt1 == sqrt0) {
return sqrt0;
}
do {
sqrt0 = sqrt1;
sqrt1 = (sqrt0 + (x / sqrt0)) >> 1;
} while (sqrt1 < sqrt0);
return sqrt0;
}
/**
* Returns the result of dividing {@code p} by {@code q}, rounding using the specified
* {@code RoundingMode}.
*
* @throws ArithmeticException if {@code q == 0}, or if {@code mode == UNNECESSARY} and {@code a}
* is not an integer multiple of {@code b}
*/
@SuppressWarnings("fallthrough")
public static long divide(long p, long q, RoundingMode mode) {
checkNotNull(mode);
long div = p / q; // throws if q == 0
long rem = p - q * div; // equals p % q
if (rem == 0) {
return div;
}
/*
* Normal Java division rounds towards 0, consistently with RoundingMode.DOWN. We just have to
* deal with the cases where rounding towards 0 is wrong, which typically depends on the sign of
* p / q.
*
* signum is 1 if p and q are both nonnegative or both negative, and -1 otherwise.
*/
int signum = 1 | (int) ((p ^ q) >> (Long.SIZE - 1));
boolean increment;
switch (mode) {
case UNNECESSARY:
checkRoundingUnnecessary(rem == 0);
// fall through
case DOWN:
increment = false;
break;
case UP:
increment = true;
break;
case CEILING:
increment = signum > 0;
break;
case FLOOR:
increment = signum < 0;
break;
case HALF_EVEN:
case HALF_DOWN:
case HALF_UP:
long absRem = abs(rem);
long cmpRemToHalfDivisor = absRem - (abs(q) - absRem);
// subtracting two nonnegative longs can't overflow
// cmpRemToHalfDivisor has the same sign as compare(abs(rem), abs(q) / 2).
if (cmpRemToHalfDivisor == 0) { // exactly on the half mark
increment = (mode == HALF_UP | (mode == HALF_EVEN & (div & 1) != 0));
} else {
increment = cmpRemToHalfDivisor > 0; // closer to the UP value
}
break;
default:
throw new AssertionError();
}
return increment ? div + signum : div;
}
/**
* Returns {@code x mod m}. This differs from {@code x % m} in that it always returns a
* non-negative result.
*
* <p>For example:
*
* <pre> {@code
*
* mod(7, 4) == 3
* mod(-7, 4) == 1
* mod(-1, 4) == 3
* mod(-8, 4) == 0
* mod(8, 4) == 0}</pre>
*
* @throws ArithmeticException if {@code m <= 0}
*/
public static int mod(long x, int m) {
// Cast is safe because the result is guaranteed in the range [0, m)
return (int) mod(x, (long) m);
}
/**
* Returns {@code x mod m}. This differs from {@code x % m} in that it always returns a
* non-negative result.
*
* <p>For example:
*
* <pre> {@code
*
* mod(7, 4) == 3
* mod(-7, 4) == 1
* mod(-1, 4) == 3
* mod(-8, 4) == 0
* mod(8, 4) == 0}</pre>
*
* @throws ArithmeticException if {@code m <= 0}
*/
public static long mod(long x, long m) {
if (m <= 0) {
throw new ArithmeticException("Modulus " + m + " must be > 0");
}
long result = x % m;
return (result >= 0) ? result : result + m;
}
/**
* Returns the greatest common divisor of {@code a, b}. Returns {@code 0} if
* {@code a == 0 && b == 0}.
*
* @throws IllegalArgumentException if {@code a < 0} or {@code b < 0}
*/
public static long gcd(long a, long b) {
/*
* The reason we require both arguments to be >= 0 is because otherwise, what do you return on
* gcd(0, Long.MIN_VALUE)? BigInteger.gcd would return positive 2^63, but positive 2^63 isn't
* an int.
*/
checkNonNegative("a", a);
checkNonNegative("b", b);
if (a == 0 | b == 0) {
return a | b;
}
/*
* Uses the binary GCD algorithm; see http://en.wikipedia.org/wiki/Binary_GCD_algorithm.
* This is over 40% faster than the Euclidean algorithm in benchmarks.
*/
int aTwos = Long.numberOfTrailingZeros(a);
a >>= aTwos; // divide out all 2s
int bTwos = Long.numberOfTrailingZeros(b);
b >>= bTwos; // divide out all 2s
while (a != b) { // both a, b are odd
if (a < b) { // swap a, b
long t = b;
b = a;
a = t;
}
a -= b; // a is now positive and even
a >>= Long.numberOfTrailingZeros(a); // divide out all 2s, since 2 doesn't divide b
}
return a << min(aTwos, bTwos);
}
/**
* Returns the sum of {@code a} and {@code b}, provided it does not overflow.
*
* @throws ArithmeticException if {@code a + b} overflows in signed {@code long} arithmetic
*/
public static long checkedAdd(long a, long b) {
long result = a + b;
checkNoOverflow((a ^ b) < 0 | (a ^ result) >= 0);
return result;
}
/**
* Returns the difference of {@code a} and {@code b}, provided it does not overflow.
*
* @throws ArithmeticException if {@code a - b} overflows in signed {@code long} arithmetic
*/
public static long checkedSubtract(long a, long b) {
long result = a - b;
checkNoOverflow((a ^ b) >= 0 | (a ^ result) >= 0);
return result;
}
/**
* Returns the product of {@code a} and {@code b}, provided it does not overflow.
*
* @throws ArithmeticException if {@code a * b} overflows in signed {@code long} arithmetic
*/
public static long checkedMultiply(long a, long b) {
// Hacker's Delight, Section 2-12
int leadingZeros = Long.numberOfLeadingZeros(a) + Long.numberOfLeadingZeros(~a)
+ Long.numberOfLeadingZeros(b) + Long.numberOfLeadingZeros(~b);
/*
* If leadingZeros > Long.SIZE + 1 it's definitely fine, if it's < Long.SIZE it's definitely
* bad. We do the leadingZeros check to avoid the division below if at all possible.
*
* Otherwise, if b == Long.MIN_VALUE, then the only allowed values of a are 0 and 1. We take
* care of all a < 0 with their own check, because in particular, the case a == -1 will
* incorrectly pass the division check below.
*
* In all other cases, we check that either a is 0 or the result is consistent with division.
*/
if (leadingZeros > Long.SIZE + 1) {
return a * b;
}
checkNoOverflow(leadingZeros >= Long.SIZE);
checkNoOverflow(a >= 0 | b != Long.MIN_VALUE);
long result = a * b;
checkNoOverflow(a == 0 || result / a == b);
return result;
}
/**
* Returns the {@code b} to the {@code k}th power, provided it does not overflow.
*
* @throws ArithmeticException if {@code b} to the {@code k}th power overflows in signed
* {@code long} arithmetic
*/
public static long checkedPow(long b, int k) {
checkNonNegative("exponent", k);
if (b >= -2 & b <= 2) {
switch ((int) b) {
case 0:
return (k == 0) ? 1 : 0;
case 1:
return 1;
case (-1):
return ((k & 1) == 0) ? 1 : -1;
case 2:
checkNoOverflow(k < Long.SIZE - 1);
return 1L << k;
case (-2):
checkNoOverflow(k < Long.SIZE);
return ((k & 1) == 0) ? (1L << k) : (-1L << k);
}
}
long accum = 1;
while (true) {
switch (k) {
case 0:
return accum;
case 1:
return checkedMultiply(accum, b);
default:
if ((k & 1) != 0) {
accum = checkedMultiply(accum, b);
}
k >>= 1;
if (k > 0) {
checkNoOverflow(b <= FLOOR_SQRT_MAX_LONG);
b *= b;
}
}
}
}
@VisibleForTesting static final long FLOOR_SQRT_MAX_LONG = 3037000499L;
/**
* Returns {@code n!}, that is, the product of the first {@code n} positive
* integers, {@code 1} if {@code n == 0}, or {@link Long#MAX_VALUE} if the
* result does not fit in a {@code long}.
*
* @throws IllegalArgumentException if {@code n < 0}
*/
public static long factorial(int n) {
checkNonNegative("n", n);
return (n < FACTORIALS.length) ? FACTORIALS[n] : Long.MAX_VALUE;
}
static final long[] FACTORIALS = {
1L,
1L,
1L * 2,
1L * 2 * 3,
1L * 2 * 3 * 4,
1L * 2 * 3 * 4 * 5,
1L * 2 * 3 * 4 * 5 * 6,
1L * 2 * 3 * 4 * 5 * 6 * 7,
1L * 2 * 3 * 4 * 5 * 6 * 7 * 8,
1L * 2 * 3 * 4 * 5 * 6 * 7 * 8 * 9,
1L * 2 * 3 * 4 * 5 * 6 * 7 * 8 * 9 * 10,
1L * 2 * 3 * 4 * 5 * 6 * 7 * 8 * 9 * 10 * 11,
1L * 2 * 3 * 4 * 5 * 6 * 7 * 8 * 9 * 10 * 11 * 12,
1L * 2 * 3 * 4 * 5 * 6 * 7 * 8 * 9 * 10 * 11 * 12 * 13,
1L * 2 * 3 * 4 * 5 * 6 * 7 * 8 * 9 * 10 * 11 * 12 * 13 * 14,
1L * 2 * 3 * 4 * 5 * 6 * 7 * 8 * 9 * 10 * 11 * 12 * 13 * 14 * 15,
1L * 2 * 3 * 4 * 5 * 6 * 7 * 8 * 9 * 10 * 11 * 12 * 13 * 14 * 15 * 16,
1L * 2 * 3 * 4 * 5 * 6 * 7 * 8 * 9 * 10 * 11 * 12 * 13 * 14 * 15 * 16 * 17,
1L * 2 * 3 * 4 * 5 * 6 * 7 * 8 * 9 * 10 * 11 * 12 * 13 * 14 * 15 * 16 * 17 * 18,
1L * 2 * 3 * 4 * 5 * 6 * 7 * 8 * 9 * 10 * 11 * 12 * 13 * 14 * 15 * 16 * 17 * 18 * 19,
1L * 2 * 3 * 4 * 5 * 6 * 7 * 8 * 9 * 10 * 11 * 12 * 13 * 14 * 15 * 16 * 17 * 18 * 19 * 20
};
/**
* Returns {@code n} choose {@code k}, also known as the binomial coefficient of {@code n} and
* {@code k}, or {@link Long#MAX_VALUE} if the result does not fit in a {@code long}.
*
* @throws IllegalArgumentException if {@code n < 0}, {@code k < 0}, or {@code k > n}
*/
public static long binomial(int n, int k) {
checkNonNegative("n", n);
checkNonNegative("k", k);
checkArgument(k <= n, "k (%s) > n (%s)", k, n);
if (k > (n >> 1)) {
k = n - k;
}
if (k >= BIGGEST_BINOMIALS.length || n > BIGGEST_BINOMIALS[k]) {
return Long.MAX_VALUE;
}
long result = 1;
if (k < BIGGEST_SIMPLE_BINOMIALS.length && n <= BIGGEST_SIMPLE_BINOMIALS[k]) {
// guaranteed not to overflow
for (int i = 0; i < k; i++) {
result *= n - i;
result /= i + 1;
}
} else {
// We want to do this in long math for speed, but want to avoid overflow.
// Dividing by the GCD suffices to avoid overflow in all the remaining cases.
for (int i = 1; i <= k; i++, n--) {
int d = IntMath.gcd(n, i);
result /= i / d; // (i/d) is guaranteed to divide result
result *= n / d;
}
}
return result;
}
/*
* binomial(BIGGEST_BINOMIALS[k], k) fits in a long, but not
* binomial(BIGGEST_BINOMIALS[k] + 1, k).
*/
static final int[] BIGGEST_BINOMIALS =
{Integer.MAX_VALUE, Integer.MAX_VALUE, Integer.MAX_VALUE, 3810779, 121977, 16175, 4337, 1733,
887, 534, 361, 265, 206, 169, 143, 125, 111, 101, 94, 88, 83, 79, 76, 74, 72, 70, 69, 68,
67, 67, 66, 66, 66, 66};
/*
* binomial(BIGGEST_SIMPLE_BINOMIALS[k], k) doesn't need to use the slower GCD-based impl,
* but binomial(BIGGEST_SIMPLE_BINOMIALS[k] + 1, k) does.
*/
@VisibleForTesting static final int[] BIGGEST_SIMPLE_BINOMIALS =
{Integer.MAX_VALUE, Integer.MAX_VALUE, Integer.MAX_VALUE, 2642246, 86251, 11724, 3218, 1313,
684, 419, 287, 214, 169, 139, 119, 105, 95, 87, 81, 76, 73, 70, 68, 66, 64, 63, 62, 62,
61, 61, 61};
// These values were generated by using checkedMultiply to see when the simple multiply/divide
// algorithm would lead to an overflow.
static boolean fitsInInt(long x) {
return (int) x == x;
}
private LongMath() {}
}
| 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.math;
import static com.google.common.base.Preconditions.checkNotNull;
import com.google.common.annotations.GwtCompatible;
import java.math.BigInteger;
/**
* A collection of preconditions for math functions.
*
* @author Louis Wasserman
*/
@GwtCompatible
final class MathPreconditions {
static int checkPositive(String role, int x) {
if (x <= 0) {
throw new IllegalArgumentException(role + " (" + x + ") must be > 0");
}
return x;
}
static long checkPositive(String role, long x) {
if (x <= 0) {
throw new IllegalArgumentException(role + " (" + x + ") must be > 0");
}
return x;
}
static BigInteger checkPositive(String role, BigInteger x) {
if (x.signum() <= 0) {
throw new IllegalArgumentException(role + " (" + x + ") must be > 0");
}
return x;
}
static int checkNonNegative(String role, int x) {
if (x < 0) {
throw new IllegalArgumentException(role + " (" + x + ") must be >= 0");
}
return x;
}
static long checkNonNegative(String role, long x) {
if (x < 0) {
throw new IllegalArgumentException(role + " (" + x + ") must be >= 0");
}
return x;
}
static BigInteger checkNonNegative(String role, BigInteger x) {
if (checkNotNull(x).signum() < 0) {
throw new IllegalArgumentException(role + " (" + x + ") must be >= 0");
}
return x;
}
static void checkRoundingUnnecessary(boolean condition) {
if (!condition) {
throw new ArithmeticException("mode was UNNECESSARY, but rounding was necessary");
}
}
static void checkInRange(boolean condition) {
if (!condition) {
throw new ArithmeticException("not in range");
}
}
static void checkNoOverflow(boolean condition) {
if (!condition) {
throw new ArithmeticException("overflow");
}
}
private MathPreconditions() {}
}
| 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.math;
import static com.google.common.base.Preconditions.checkArgument;
import java.math.BigInteger;
/**
* Utilities for {@code double} primitives. Some of these are exposed in JDK 6,
* but we can't depend on them there.
*
* @author Louis Wasserman
*/
final class DoubleUtils {
private DoubleUtils() {
}
static double nextDown(double d) {
return -Math.nextUp(-d);
}
// The mask for the significand, according to the {@link
// Double#doubleToRawLongBits(double)} spec.
static final long SIGNIFICAND_MASK = 0x000fffffffffffffL;
// The mask for the exponent, according to the {@link
// Double#doubleToRawLongBits(double)} spec.
static final long EXPONENT_MASK = 0x7ff0000000000000L;
// The mask for the sign, according to the {@link
// Double#doubleToRawLongBits(double)} spec.
static final long SIGN_MASK = 0x8000000000000000L;
static final int SIGNIFICAND_BITS = 52;
static final int EXPONENT_BIAS = 1023;
/**
* The implicit 1 bit that is omitted in significands of normal doubles.
*/
static final long IMPLICIT_BIT = SIGNIFICAND_MASK + 1;
static long getSignificand(double d) {
checkArgument(isFinite(d), "not a normal value");
int exponent = Math.getExponent(d);
long bits = Double.doubleToRawLongBits(d);
bits &= SIGNIFICAND_MASK;
return (exponent == Double.MIN_EXPONENT - 1)
? bits << 1
: bits | IMPLICIT_BIT;
}
static boolean isFinite(double d) {
return Math.getExponent(d) <= Double.MAX_EXPONENT;
}
static boolean isNormal(double d) {
return Math.getExponent(d) >= Double.MIN_EXPONENT;
}
/*
* Returns x scaled by a power of 2 such that it is in the range [1, 2). Assumes x is positive,
* normal, and finite.
*/
static double scaleNormalize(double x) {
long significand = Double.doubleToRawLongBits(x) & SIGNIFICAND_MASK;
return Double.longBitsToDouble(significand | ONE_BITS);
}
static double bigToDouble(BigInteger x) {
// This is an extremely fast implementation of BigInteger.doubleValue(). JDK patch pending.
BigInteger absX = x.abs();
int exponent = absX.bitLength() - 1;
// exponent == floor(log2(abs(x)))
if (exponent < Long.SIZE - 1) {
return x.longValue();
} else if (exponent > Double.MAX_EXPONENT) {
return x.signum() * Double.POSITIVE_INFINITY;
}
/*
* We need the top SIGNIFICAND_BITS + 1 bits, including the "implicit" one bit. To make
* rounding easier, we pick out the top SIGNIFICAND_BITS + 2 bits, so we have one to help us
* round up or down. twiceSignifFloor will contain the top SIGNIFICAND_BITS + 2 bits, and
* signifFloor the top SIGNIFICAND_BITS + 1.
*
* It helps to consider the real number signif = absX * 2^(SIGNIFICAND_BITS - exponent).
*/
int shift = exponent - SIGNIFICAND_BITS - 1;
long twiceSignifFloor = absX.shiftRight(shift).longValue();
long signifFloor = twiceSignifFloor >> 1;
signifFloor &= SIGNIFICAND_MASK; // remove the implied bit
/*
* We round up if either the fractional part of signif is strictly greater than 0.5 (which is
* true if the 0.5 bit is set and any lower bit is set), or if the fractional part of signif is
* >= 0.5 and signifFloor is odd (which is true if both the 0.5 bit and the 1 bit are set).
*/
boolean increment = (twiceSignifFloor & 1) != 0
&& ((signifFloor & 1) != 0 || absX.getLowestSetBit() < shift);
long signifRounded = increment ? signifFloor + 1 : signifFloor;
long bits = (long) ((exponent + EXPONENT_BIAS)) << SIGNIFICAND_BITS;
bits += signifRounded;
/*
* If signifRounded == 2^53, we'd need to set all of the significand bits to zero and add 1 to
* the exponent. This is exactly the behavior we get from just adding signifRounded to bits
* directly. If the exponent is MAX_DOUBLE_EXPONENT, we round up (correctly) to
* Double.POSITIVE_INFINITY.
*/
bits |= x.signum() & SIGN_MASK;
return Double.longBitsToDouble(bits);
}
/**
* Returns its argument if it is non-negative, zero if it is negative.
*/
static double ensureNonNegative(double value) {
checkArgument(!Double.isNaN(value));
if (value > 0.0) {
return value;
} else {
return 0.0;
}
}
private static final long ONE_BITS = Double.doubleToRawLongBits(1.0);
}
| 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.math;
import static com.google.common.base.Preconditions.checkArgument;
import static com.google.common.base.Preconditions.checkNotNull;
import static com.google.common.math.MathPreconditions.checkNoOverflow;
import static com.google.common.math.MathPreconditions.checkNonNegative;
import static com.google.common.math.MathPreconditions.checkPositive;
import static com.google.common.math.MathPreconditions.checkRoundingUnnecessary;
import static java.lang.Math.abs;
import static java.math.RoundingMode.HALF_EVEN;
import static java.math.RoundingMode.HALF_UP;
import com.google.common.annotations.Beta;
import com.google.common.annotations.GwtCompatible;
import com.google.common.annotations.GwtIncompatible;
import com.google.common.annotations.VisibleForTesting;
import java.math.BigInteger;
import java.math.RoundingMode;
/**
* A class for arithmetic on values of type {@code int}. Where possible, methods are defined and
* named analogously to their {@code BigInteger} counterparts.
*
* <p>The implementations of many methods in this class are based on material from Henry S. Warren,
* Jr.'s <i>Hacker's Delight</i>, (Addison Wesley, 2002).
*
* <p>Similar functionality for {@code long} and for {@link BigInteger} can be found in
* {@link LongMath} and {@link BigIntegerMath} respectively. For other common operations on
* {@code int} values, see {@link com.google.common.primitives.Ints}.
*
* @author Louis Wasserman
* @since 11.0
*/
@Beta
@GwtCompatible(emulated = true)
public final class IntMath {
// NOTE: Whenever both tests are cheap and functional, it's faster to use &, | instead of &&, ||
/**
* Returns {@code true} if {@code x} represents a power of two.
*
* <p>This differs from {@code Integer.bitCount(x) == 1}, because
* {@code Integer.bitCount(Integer.MIN_VALUE) == 1}, but {@link Integer#MIN_VALUE} is not a power
* of two.
*/
public static boolean isPowerOfTwo(int x) {
return x > 0 & (x & (x - 1)) == 0;
}
/**
* Returns the base-2 logarithm of {@code x}, rounded according to the specified rounding mode.
*
* @throws IllegalArgumentException if {@code x <= 0}
* @throws ArithmeticException if {@code mode} is {@link RoundingMode#UNNECESSARY} and {@code x}
* is not a power of two
*/
@GwtIncompatible("need BigIntegerMath to adequately test")
@SuppressWarnings("fallthrough")
public static int log2(int x, RoundingMode mode) {
checkPositive("x", x);
switch (mode) {
case UNNECESSARY:
checkRoundingUnnecessary(isPowerOfTwo(x));
// fall through
case DOWN:
case FLOOR:
return (Integer.SIZE - 1) - Integer.numberOfLeadingZeros(x);
case UP:
case CEILING:
return Integer.SIZE - Integer.numberOfLeadingZeros(x - 1);
case HALF_DOWN:
case HALF_UP:
case HALF_EVEN:
// Since sqrt(2) is irrational, log2(x) - logFloor cannot be exactly 0.5
int leadingZeros = Integer.numberOfLeadingZeros(x);
int cmp = MAX_POWER_OF_SQRT2_UNSIGNED >>> leadingZeros;
// floor(2^(logFloor + 0.5))
int logFloor = (Integer.SIZE - 1) - leadingZeros;
return (x <= cmp) ? logFloor : logFloor + 1;
default:
throw new AssertionError();
}
}
/** The biggest half power of two that can fit in an unsigned int. */
@VisibleForTesting static final int MAX_POWER_OF_SQRT2_UNSIGNED = 0xB504F333;
/**
* Returns the base-10 logarithm of {@code x}, rounded according to the specified rounding mode.
*
* @throws IllegalArgumentException if {@code x <= 0}
* @throws ArithmeticException if {@code mode} is {@link RoundingMode#UNNECESSARY} and {@code x}
* is not a power of ten
*/
@GwtIncompatible("need BigIntegerMath to adequately test")
@SuppressWarnings("fallthrough")
public static int log10(int x, RoundingMode mode) {
checkPositive("x", x);
int logFloor = log10Floor(x);
int floorPow = POWERS_OF_10[logFloor];
switch (mode) {
case UNNECESSARY:
checkRoundingUnnecessary(x == floorPow);
// fall through
case FLOOR:
case DOWN:
return logFloor;
case CEILING:
case UP:
return (x == floorPow) ? logFloor : logFloor + 1;
case HALF_DOWN:
case HALF_UP:
case HALF_EVEN:
// sqrt(10) is irrational, so log10(x) - logFloor is never exactly 0.5
return (x <= HALF_POWERS_OF_10[logFloor]) ? logFloor : logFloor + 1;
default:
throw new AssertionError();
}
}
private static int log10Floor(int x) {
for (int i = 1; i < POWERS_OF_10.length; i++) {
if (x < POWERS_OF_10[i]) {
return i - 1;
}
}
return POWERS_OF_10.length - 1;
}
@VisibleForTesting static final int[] POWERS_OF_10 =
{1, 10, 100, 1000, 10000, 100000, 1000000, 10000000, 100000000, 1000000000};
// HALF_POWERS_OF_10[i] = largest int less than 10^(i + 0.5)
@VisibleForTesting static final int[] HALF_POWERS_OF_10 =
{3, 31, 316, 3162, 31622, 316227, 3162277, 31622776, 316227766, Integer.MAX_VALUE};
/**
* Returns {@code b} to the {@code k}th power. Even if the result overflows, it will be equal to
* {@code BigInteger.valueOf(b).pow(k).intValue()}. This implementation runs in {@code O(log k)}
* time.
*
* <p>Compare {@link #checkedPow}, which throws an {@link ArithmeticException} upon overflow.
*
* @throws IllegalArgumentException if {@code k < 0}
*/
@GwtIncompatible("failing tests")
public static int pow(int b, int k) {
checkNonNegative("exponent", k);
switch (b) {
case 0:
return (k == 0) ? 1 : 0;
case 1:
return 1;
case (-1):
return ((k & 1) == 0) ? 1 : -1;
case 2:
return (k < Integer.SIZE) ? (1 << k) : 0;
case (-2):
if (k < Integer.SIZE) {
return ((k & 1) == 0) ? (1 << k) : -(1 << k);
} else {
return 0;
}
}
for (int accum = 1;; k >>= 1) {
switch (k) {
case 0:
return accum;
case 1:
return b * accum;
default:
accum *= ((k & 1) == 0) ? 1 : b;
b *= b;
}
}
}
/**
* Returns the square root of {@code x}, rounded with the specified rounding mode.
*
* @throws IllegalArgumentException if {@code x < 0}
* @throws ArithmeticException if {@code mode} is {@link RoundingMode#UNNECESSARY} and
* {@code sqrt(x)} is not an integer
*/
@GwtIncompatible("need BigIntegerMath to adequately test")
@SuppressWarnings("fallthrough")
public static int sqrt(int x, RoundingMode mode) {
checkNonNegative("x", x);
int sqrtFloor = sqrtFloor(x);
switch (mode) {
case UNNECESSARY:
checkRoundingUnnecessary(sqrtFloor * sqrtFloor == x); // fall through
case FLOOR:
case DOWN:
return sqrtFloor;
case CEILING:
case UP:
return (sqrtFloor * sqrtFloor == x) ? sqrtFloor : sqrtFloor + 1;
case HALF_DOWN:
case HALF_UP:
case HALF_EVEN:
int halfSquare = sqrtFloor * sqrtFloor + sqrtFloor;
/*
* We wish to test whether or not x <= (sqrtFloor + 0.5)^2 = halfSquare + 0.25.
* Since both x and halfSquare are integers, this is equivalent to testing whether or not
* x <= halfSquare. (We have to deal with overflow, though.)
*/
return (x <= halfSquare | halfSquare < 0) ? sqrtFloor : sqrtFloor + 1;
default:
throw new AssertionError();
}
}
private static int sqrtFloor(int x) {
// There is no loss of precision in converting an int to a double, according to
// http://java.sun.com/docs/books/jls/third_edition/html/conversions.html#5.1.2
return (int) Math.sqrt(x);
}
/**
* Returns the result of dividing {@code p} by {@code q}, rounding using the specified
* {@code RoundingMode}.
*
* @throws ArithmeticException if {@code q == 0}, or if {@code mode == UNNECESSARY} and {@code a}
* is not an integer multiple of {@code b}
*/
@GwtIncompatible("failing tests")
@SuppressWarnings("fallthrough")
public static int divide(int p, int q, RoundingMode mode) {
checkNotNull(mode);
if (q == 0) {
throw new ArithmeticException("/ by zero"); // for GWT
}
int div = p / q;
int rem = p - q * div; // equal to p % q
if (rem == 0) {
return div;
}
/*
* Normal Java division rounds towards 0, consistently with RoundingMode.DOWN. We just have to
* deal with the cases where rounding towards 0 is wrong, which typically depends on the sign of
* p / q.
*
* signum is 1 if p and q are both nonnegative or both negative, and -1 otherwise.
*/
int signum = 1 | ((p ^ q) >> (Integer.SIZE - 1));
boolean increment;
switch (mode) {
case UNNECESSARY:
checkRoundingUnnecessary(rem == 0);
// fall through
case DOWN:
increment = false;
break;
case UP:
increment = true;
break;
case CEILING:
increment = signum > 0;
break;
case FLOOR:
increment = signum < 0;
break;
case HALF_EVEN:
case HALF_DOWN:
case HALF_UP:
int absRem = abs(rem);
int cmpRemToHalfDivisor = absRem - (abs(q) - absRem);
// subtracting two nonnegative ints can't overflow
// cmpRemToHalfDivisor has the same sign as compare(abs(rem), abs(q) / 2).
if (cmpRemToHalfDivisor == 0) { // exactly on the half mark
increment = (mode == HALF_UP || (mode == HALF_EVEN & (div & 1) != 0));
} else {
increment = cmpRemToHalfDivisor > 0; // closer to the UP value
}
break;
default:
throw new AssertionError();
}
return increment ? div + signum : div;
}
/**
* Returns {@code x mod m}. This differs from {@code x % m} in that it always returns a
* non-negative result.
*
* <p>For example:<pre> {@code
*
* mod(7, 4) == 3
* mod(-7, 4) == 1
* mod(-1, 4) == 3
* mod(-8, 4) == 0
* mod(8, 4) == 0}</pre>
*
* @throws ArithmeticException if {@code m <= 0}
*/
public static int mod(int x, int m) {
if (m <= 0) {
throw new ArithmeticException("Modulus " + m + " must be > 0");
}
int result = x % m;
return (result >= 0) ? result : result + m;
}
/**
* Returns the greatest common divisor of {@code a, b}. Returns {@code 0} if
* {@code a == 0 && b == 0}.
*
* @throws IllegalArgumentException if {@code a < 0} or {@code b < 0}
*/
public static int gcd(int a, int b) {
/*
* The reason we require both arguments to be >= 0 is because otherwise, what do you return on
* gcd(0, Integer.MIN_VALUE)? BigInteger.gcd would return positive 2^31, but positive 2^31
* isn't an int.
*/
checkNonNegative("a", a);
checkNonNegative("b", b);
// The simple Euclidean algorithm is the fastest for ints, and is easily the most readable.
while (b != 0) {
int t = b;
b = a % b;
a = t;
}
return a;
}
/**
* Returns the sum of {@code a} and {@code b}, provided it does not overflow.
*
* @throws ArithmeticException if {@code a + b} overflows in signed {@code int} arithmetic
*/
public static int checkedAdd(int a, int b) {
long result = (long) a + b;
checkNoOverflow(result == (int) result);
return (int) result;
}
/**
* Returns the difference of {@code a} and {@code b}, provided it does not overflow.
*
* @throws ArithmeticException if {@code a - b} overflows in signed {@code int} arithmetic
*/
public static int checkedSubtract(int a, int b) {
long result = (long) a - b;
checkNoOverflow(result == (int) result);
return (int) result;
}
/**
* Returns the product of {@code a} and {@code b}, provided it does not overflow.
*
* @throws ArithmeticException if {@code a * b} overflows in signed {@code int} arithmetic
*/
public static int checkedMultiply(int a, int b) {
long result = (long) a * b;
checkNoOverflow(result == (int) result);
return (int) result;
}
/**
* Returns the {@code b} to the {@code k}th power, provided it does not overflow.
*
* <p>{@link #pow} may be faster, but does not check for overflow.
*
* @throws ArithmeticException if {@code b} to the {@code k}th power overflows in signed
* {@code int} arithmetic
*/
@GwtIncompatible("failing tests")
public static int checkedPow(int b, int k) {
checkNonNegative("exponent", k);
switch (b) {
case 0:
return (k == 0) ? 1 : 0;
case 1:
return 1;
case (-1):
return ((k & 1) == 0) ? 1 : -1;
case 2:
checkNoOverflow(k < Integer.SIZE - 1);
return 1 << k;
case (-2):
checkNoOverflow(k < Integer.SIZE);
return ((k & 1) == 0) ? 1 << k : -1 << k;
}
int accum = 1;
while (true) {
switch (k) {
case 0:
return accum;
case 1:
return checkedMultiply(accum, b);
default:
if ((k & 1) != 0) {
accum = checkedMultiply(accum, b);
}
k >>= 1;
if (k > 0) {
checkNoOverflow(-FLOOR_SQRT_MAX_INT <= b & b <= FLOOR_SQRT_MAX_INT);
b *= b;
}
}
}
}
@VisibleForTesting static final int FLOOR_SQRT_MAX_INT = 46340;
/**
* Returns {@code n!}, that is, the product of the first {@code n} positive
* integers, {@code 1} if {@code n == 0}, or {@link Integer#MAX_VALUE} if the
* result does not fit in a {@code int}.
*
* @throws IllegalArgumentException if {@code n < 0}
*/
@GwtIncompatible("need BigIntegerMath to adequately test")
public static int factorial(int n) {
checkNonNegative("n", n);
return (n < FACTORIALS.length) ? FACTORIALS[n] : Integer.MAX_VALUE;
}
static final int[] FACTORIALS = {
1,
1,
1 * 2,
1 * 2 * 3,
1 * 2 * 3 * 4,
1 * 2 * 3 * 4 * 5,
1 * 2 * 3 * 4 * 5 * 6,
1 * 2 * 3 * 4 * 5 * 6 * 7,
1 * 2 * 3 * 4 * 5 * 6 * 7 * 8,
1 * 2 * 3 * 4 * 5 * 6 * 7 * 8 * 9,
1 * 2 * 3 * 4 * 5 * 6 * 7 * 8 * 9 * 10,
1 * 2 * 3 * 4 * 5 * 6 * 7 * 8 * 9 * 10 * 11,
1 * 2 * 3 * 4 * 5 * 6 * 7 * 8 * 9 * 10 * 11 * 12};
/**
* Returns {@code n} choose {@code k}, also known as the binomial coefficient of {@code n} and
* {@code k}, or {@link Integer#MAX_VALUE} if the result does not fit in an {@code int}.
*
* @throws IllegalArgumentException if {@code n < 0}, {@code k < 0} or {@code k > n}
*/
@GwtIncompatible("need BigIntegerMath to adequately test")
public static int binomial(int n, int k) {
checkNonNegative("n", n);
checkNonNegative("k", k);
checkArgument(k <= n, "k (%s) > n (%s)", k, n);
if (k > (n >> 1)) {
k = n - k;
}
if (k >= BIGGEST_BINOMIALS.length || n > BIGGEST_BINOMIALS[k]) {
return Integer.MAX_VALUE;
}
switch (k) {
case 0:
return 1;
case 1:
return n;
default:
long result = 1;
for (int i = 0; i < k; i++) {
result *= n - i;
result /= i + 1;
}
return (int) result;
}
}
// binomial(BIGGEST_BINOMIALS[k], k) fits in an int, but not binomial(BIGGEST_BINOMIALS[k]+1,k).
@VisibleForTesting static int[] BIGGEST_BINOMIALS = {
Integer.MAX_VALUE,
Integer.MAX_VALUE,
65536,
2345,
477,
193,
110,
75,
58,
49,
43,
39,
37,
35,
34,
34,
33
};
private IntMath() {}
}
| 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.eventbus;
import com.google.common.collect.Multimap;
/**
* A method for finding event handler methods in objects, for use by
* {@link EventBus}.
*
* @author Cliff Biffle
*/
interface HandlerFindingStrategy {
/**
* Finds all suitable event handler methods in {@code source}, organizes them
* by the type of event they handle, and wraps them in {@link EventHandler}s.
*
* @param source object whose handlers are desired.
* @return EventHandler objects for each handler method, organized by event
* type.
*
* @throws IllegalArgumentException if {@code source} is not appropriate for
* this strategy (in ways that this interface does not define).
*/
Multimap<Class<?>, EventHandler> findAllHandlers(Object source);
}
| 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.eventbus;
import com.google.common.annotations.Beta;
import java.lang.annotation.ElementType;
import java.lang.annotation.Retention;
import java.lang.annotation.RetentionPolicy;
import java.lang.annotation.Target;
/**
* Marks an event handling method as being thread-safe. This annotation
* indicates that EventBus may invoke the event handler simultaneously from
* multiple threads.
*
* <p>This does not mark the method as an event handler, and so should be used
* in combination with {@link Subscribe}.
*
* @author Cliff Biffle
* @since 10.0
*/
@Retention(RetentionPolicy.RUNTIME)
@Target(ElementType.METHOD)
@Beta
public @interface AllowConcurrentEvents {
}
| 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.eventbus;
import com.google.common.annotations.Beta;
/**
* Wraps an event that was posted, but which had no subscribers and thus could
* not be delivered.
*
* <p>Subscribing a DeadEvent handler is useful for debugging or logging, as it
* can detect misconfigurations in a system's event distribution.
*
* @author Cliff Biffle
* @since 10.0
*/
@Beta
public class DeadEvent {
private final Object source;
private final Object event;
/**
* Creates a new DeadEvent.
*
* @param source object broadcasting the DeadEvent (generally the
* {@link EventBus}).
* @param event the event that could not be delivered.
*/
public DeadEvent(Object source, Object event) {
this.source = source;
this.event = event;
}
/**
* Returns the object that originated this event (<em>not</em> the object that
* originated the wrapped event). This is generally an {@link EventBus}.
*
* @return the source of this event.
*/
public Object getSource() {
return source;
}
/**
* Returns the wrapped, 'dead' event, which the system was unable to deliver
* to any registered handler.
*
* @return the 'dead' event that could not be delivered.
*/
public Object getEvent() {
return event;
}
}
| 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.eventbus;
import com.google.common.collect.HashMultimap;
import com.google.common.collect.Multimap;
import java.lang.reflect.Method;
/**
* A {@link HandlerFindingStrategy} for collecting all event handler methods
* that are marked with the {@link Subscribe} annotation.
*
* @author Cliff Biffle
*/
class AnnotatedHandlerFinder implements HandlerFindingStrategy {
/**
* {@inheritDoc}
*
* This implementation finds all methods marked with a {@link Subscribe}
* annotation.
*/
@Override
public Multimap<Class<?>, EventHandler> findAllHandlers(Object listener) {
Multimap<Class<?>, EventHandler> methodsInListener =
HashMultimap.create();
Class clazz = listener.getClass();
while (clazz != null) {
for (Method method : clazz.getMethods()) {
Subscribe annotation = method.getAnnotation(Subscribe.class);
if (annotation != null) {
Class<?>[] parameterTypes = method.getParameterTypes();
if (parameterTypes.length != 1) {
throw new IllegalArgumentException(
"Method " + method + " has @Subscribe annotation, but requires " +
parameterTypes.length + " arguments. Event handler methods " +
"must require a single argument.");
}
Class<?> eventType = parameterTypes[0];
EventHandler handler = makeHandler(listener, method);
methodsInListener.put(eventType, handler);
}
}
clazz = clazz.getSuperclass();
}
return methodsInListener;
}
/**
* Creates an {@code EventHandler} for subsequently calling {@code method} on
* {@code listener}.
* Selects an EventHandler implementation based on the annotations on
* {@code method}.
*
* @param listener object bearing the event handler method.
* @param method the event handler method to wrap in an EventHandler.
* @return an EventHandler that will call {@code method} on {@code listener}
* when invoked.
*/
private static EventHandler makeHandler(Object listener, Method method) {
EventHandler wrapper;
if (methodIsDeclaredThreadSafe(method)) {
wrapper = new EventHandler(listener, method);
} else {
wrapper = new SynchronizedEventHandler(listener, method);
}
return wrapper;
}
/**
* Checks whether {@code method} is thread-safe, as indicated by the
* {@link AllowConcurrentEvents} annotation.
*
* @param method handler method to check.
* @return {@code true} if {@code handler} is marked as thread-safe,
* {@code false} otherwise.
*/
private static boolean methodIsDeclaredThreadSafe(Method method) {
return method.getAnnotation(AllowConcurrentEvents.class) != null;
}
}
| 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.eventbus;
import com.google.common.annotations.Beta;
import com.google.common.annotations.VisibleForTesting;
import com.google.common.base.Supplier;
import com.google.common.base.Throwables;
import com.google.common.cache.CacheBuilder;
import com.google.common.cache.CacheLoader;
import com.google.common.cache.LoadingCache;
import com.google.common.collect.Lists;
import com.google.common.collect.Multimap;
import com.google.common.collect.Multimaps;
import com.google.common.collect.SetMultimap;
import com.google.common.collect.Sets;
import java.lang.reflect.InvocationTargetException;
import java.util.Collection;
import java.util.List;
import java.util.Map.Entry;
import java.util.Set;
import java.util.concurrent.ConcurrentHashMap;
import java.util.concurrent.ConcurrentLinkedQueue;
import java.util.concurrent.CopyOnWriteArraySet;
import java.util.concurrent.ExecutionException;
import java.util.logging.Level;
import java.util.logging.Logger;
/**
* Dispatches events to listeners, and provides ways for listeners to register
* themselves.
*
* <p>The EventBus allows publish-subscribe-style communication between
* components without requiring the components to explicitly register with one
* another (and thus be aware of each other). It is designed exclusively to
* replace traditional Java in-process event distribution using explicit
* registration. It is <em>not</em> a general-purpose publish-subscribe system,
* nor is it intended for interprocess communication.
*
* <h2>Receiving Events</h2>
* To receive events, an object should:<ol>
* <li>Expose a public method, known as the <i>event handler</i>, which accepts
* a single argument of the type of event desired;</li>
* <li>Mark it with a {@link Subscribe} annotation;</li>
* <li>Pass itself to an EventBus instance's {@link #register(Object)} method.
* </li>
* </ol>
*
* <h2>Posting Events</h2>
* To post an event, simply provide the event object to the
* {@link #post(Object)} method. The EventBus instance will determine the type
* of event and route it to all registered listeners.
*
* <p>Events are routed based on their type — an event will be delivered
* to any handler for any type to which the event is <em>assignable.</em> This
* includes implemented interfaces, all superclasses, and all interfaces
* implemented by superclasses.
*
* <p>When {@code post} is called, all registered handlers for an event are run
* in sequence, so handlers should be reasonably quick. If an event may trigger
* an extended process (such as a database load), spawn a thread or queue it for
* later. (For a convenient way to do this, use an {@link AsyncEventBus}.)
*
* <h2>Handler Methods</h2>
* Event handler methods must accept only one argument: the event.
*
* <p>Handlers should not, in general, throw. If they do, the EventBus will
* catch and log the exception. This is rarely the right solution for error
* handling and should not be relied upon; it is intended solely to help find
* problems during development.
*
* <p>The EventBus guarantees that it will not call a handler method from
* multiple threads simultaneously, unless the method explicitly allows it by
* bearing the {@link AllowConcurrentEvents} annotation. If this annotation is
* not present, handler methods need not worry about being reentrant, unless
* also called from outside the EventBus.
*
* <h2>Dead Events</h2>
* If an event is posted, but no registered handlers can accept it, it is
* considered "dead." To give the system a second chance to handle dead events,
* they are wrapped in an instance of {@link DeadEvent} and reposted.
*
* <p>If a handler for a supertype of all events (such as Object) is registered,
* no event will ever be considered dead, and no DeadEvents will be generated.
* Accordingly, while DeadEvent extends {@link Object}, a handler registered to
* receive any Object will never receive a DeadEvent.
*
* <p>This class is safe for concurrent use.
*
* <p>See the Guava User Guide article on <a href=
* "http://code.google.com/p/guava-libraries/wiki/EventBusExplained">
* {@code EventBus}</a>.
*
* @author Cliff Biffle
* @since 10.0
*/
@Beta
public class EventBus {
/**
* All registered event handlers, indexed by event type.
*/
private final SetMultimap<Class<?>, EventHandler> handlersByType =
Multimaps.newSetMultimap(new ConcurrentHashMap<Class<?>, Collection<EventHandler>>(),
new Supplier<Set<EventHandler>>() {
@Override
public Set<EventHandler> get() {
return new CopyOnWriteArraySet<EventHandler>();
}
});
/**
* Logger for event dispatch failures. Named by the fully-qualified name of
* this class, followed by the identifier provided at construction.
*/
private final Logger logger;
/**
* Strategy for finding handler methods in registered objects. Currently,
* only the {@link AnnotatedHandlerFinder} is supported, but this is
* encapsulated for future expansion.
*/
private final HandlerFindingStrategy finder = new AnnotatedHandlerFinder();
/** queues of events for the current thread to dispatch */
private final ThreadLocal<ConcurrentLinkedQueue<EventWithHandler>>
eventsToDispatch =
new ThreadLocal<ConcurrentLinkedQueue<EventWithHandler>>() {
@Override protected ConcurrentLinkedQueue<EventWithHandler> initialValue() {
return new ConcurrentLinkedQueue<EventWithHandler>();
}
};
/** true if the current thread is currently dispatching an event */
private final ThreadLocal<Boolean> isDispatching =
new ThreadLocal<Boolean>() {
@Override protected Boolean initialValue() {
return false;
}
};
/**
* A thread-safe cache for flattenHierarch(). The Class class is immutable.
*/
private LoadingCache<Class<?>, Set<Class<?>>> flattenHierarchyCache =
CacheBuilder.newBuilder()
.weakKeys()
.build(new CacheLoader<Class<?>, Set<Class<?>>>() {
@Override
public Set<Class<?>> load(Class<?> concreteClass) throws Exception {
List<Class<?>> parents = Lists.newLinkedList();
Set<Class<?>> classes = Sets.newHashSet();
parents.add(concreteClass);
while (!parents.isEmpty()) {
Class<?> clazz = parents.remove(0);
classes.add(clazz);
Class<?> parent = clazz.getSuperclass();
if (parent != null) {
parents.add(parent);
}
for (Class<?> iface : clazz.getInterfaces()) {
parents.add(iface);
}
}
return classes;
}
});
/**
* Creates a new EventBus named "default".
*/
public EventBus() {
this("default");
}
/**
* Creates a new EventBus with the given {@code identifier}.
*
* @param identifier a brief name for this bus, for logging purposes. Should
* be a valid Java identifier.
*/
public EventBus(String identifier) {
logger = Logger.getLogger(EventBus.class.getName() + "." + identifier);
}
/**
* Registers all handler methods on {@code object} to receive events.
* Handler methods are selected and classified using this EventBus's
* {@link HandlerFindingStrategy}; the default strategy is the
* {@link AnnotatedHandlerFinder}.
*
* @param object object whose handler methods should be registered.
*/
public void register(Object object) {
handlersByType.putAll(finder.findAllHandlers(object));
}
/**
* Unregisters all handler methods on a registered {@code object}.
*
* @param object object whose handler methods should be unregistered.
* @throws IllegalArgumentException if the object was not previously registered.
*/
public void unregister(Object object) {
Multimap<Class<?>, EventHandler> methodsInListener = finder.findAllHandlers(object);
for (Entry<Class<?>, Collection<EventHandler>> entry : methodsInListener.asMap().entrySet()) {
Set<EventHandler> currentHandlers = getHandlersForEventType(entry.getKey());
Collection<EventHandler> eventMethodsInListener = entry.getValue();
if (currentHandlers == null || !currentHandlers.containsAll(entry.getValue())) {
throw new IllegalArgumentException(
"missing event handler for an annotated method. Is " + object + " registered?");
}
currentHandlers.removeAll(eventMethodsInListener);
}
}
/**
* Posts an event to all registered handlers. This method will return
* successfully after the event has been posted to all handlers, and
* regardless of any exceptions thrown by handlers.
*
* <p>If no handlers have been subscribed for {@code event}'s class, and
* {@code event} is not already a {@link DeadEvent}, it will be wrapped in a
* DeadEvent and reposted.
*
* @param event event to post.
*/
public void post(Object event) {
Set<Class<?>> dispatchTypes = flattenHierarchy(event.getClass());
boolean dispatched = false;
for (Class<?> eventType : dispatchTypes) {
Set<EventHandler> wrappers = getHandlersForEventType(eventType);
if (wrappers != null && !wrappers.isEmpty()) {
dispatched = true;
for (EventHandler wrapper : wrappers) {
enqueueEvent(event, wrapper);
}
}
}
if (!dispatched && !(event instanceof DeadEvent)) {
post(new DeadEvent(this, event));
}
dispatchQueuedEvents();
}
/**
* Queue the {@code event} for dispatch during
* {@link #dispatchQueuedEvents()}. Events are queued in-order of occurrence
* so they can be dispatched in the same order.
*/
protected void enqueueEvent(Object event, EventHandler handler) {
eventsToDispatch.get().offer(new EventWithHandler(event, handler));
}
/**
* Drain the queue of events to be dispatched. As the queue is being drained,
* new events may be posted to the end of the queue.
*/
protected void dispatchQueuedEvents() {
// don't dispatch if we're already dispatching, that would allow reentrancy
// and out-of-order events. Instead, leave the events to be dispatched
// after the in-progress dispatch is complete.
if (isDispatching.get()) {
return;
}
isDispatching.set(true);
try {
while (true) {
EventWithHandler eventWithHandler = eventsToDispatch.get().poll();
if (eventWithHandler == null) {
break;
}
dispatch(eventWithHandler.event, eventWithHandler.handler);
}
} finally {
isDispatching.set(false);
}
}
/**
* Dispatches {@code event} to the handler in {@code wrapper}. This method
* is an appropriate override point for subclasses that wish to make
* event delivery asynchronous.
*
* @param event event to dispatch.
* @param wrapper wrapper that will call the handler.
*/
protected void dispatch(Object event, EventHandler wrapper) {
try {
wrapper.handleEvent(event);
} catch (InvocationTargetException e) {
logger.log(Level.SEVERE,
"Could not dispatch event: " + event + " to handler " + wrapper, e);
}
}
/**
* Retrieves a mutable set of the currently registered handlers for
* {@code type}. If no handlers are currently registered for {@code type},
* this method may either return {@code null} or an empty set.
*
* @param type type of handlers to retrieve.
* @return currently registered handlers, or {@code null}.
*/
Set<EventHandler> getHandlersForEventType(Class<?> type) {
return handlersByType.get(type);
}
/**
* Creates a new Set for insertion into the handler map. This is provided
* as an override point for subclasses. The returned set should support
* concurrent access.
*
* @return a new, mutable set for handlers.
*/
protected Set<EventHandler> newHandlerSet() {
return new CopyOnWriteArraySet<EventHandler>();
}
/**
* Flattens a class's type hierarchy into a set of Class objects. The set
* will include all superclasses (transitively), and all interfaces
* implemented by these superclasses.
*
* @param concreteClass class whose type hierarchy will be retrieved.
* @return {@code clazz}'s complete type hierarchy, flattened and uniqued.
*/
@VisibleForTesting
Set<Class<?>> flattenHierarchy(Class<?> concreteClass) {
try {
return flattenHierarchyCache.get(concreteClass);
} catch (ExecutionException e) {
throw Throwables.propagate(e.getCause());
}
}
/** simple struct representing an event and it's handler */
static class EventWithHandler {
final Object event;
final EventHandler handler;
public EventWithHandler(Object event, EventHandler handler) {
this.event = event;
this.handler = handler;
}
}
}
| 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.eventbus;
import com.google.common.base.Preconditions;
import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;
/**
* Wraps a single-argument 'handler' method on a specific object.
*
* <p>This class only verifies the suitability of the method and event type if
* something fails. Callers are expected to verify their uses of this class.
*
* <p>Two EventHandlers are equivalent when they refer to the same method on the
* same object (not class). This property is used to ensure that no handler
* method is registered more than once.
*
* @author Cliff Biffle
*/
class EventHandler {
/** Object sporting the handler method. */
private final Object target;
/** Handler method. */
private final Method method;
/**
* Creates a new EventHandler to wrap {@code method} on @{code target}.
*
* @param target object to which the method applies.
* @param method handler method.
*/
EventHandler(Object target, Method method) {
Preconditions.checkNotNull(target,
"EventHandler target cannot be null.");
Preconditions.checkNotNull(method, "EventHandler method cannot be null.");
this.target = target;
this.method = method;
method.setAccessible(true);
}
/**
* Invokes the wrapped handler method to handle {@code event}.
*
* @param event event to handle
* @throws InvocationTargetException if the wrapped method throws any
* {@link Throwable} that is not an {@link Error} ({@code Error}s are
* propagated as-is).
*/
public void handleEvent(Object event) throws InvocationTargetException {
try {
method.invoke(target, new Object[] { event });
} catch (IllegalArgumentException e) {
throw new Error("Method rejected target/argument: " + event, e);
} catch (IllegalAccessException e) {
throw new Error("Method became inaccessible: " + event, e);
} catch (InvocationTargetException e) {
if (e.getCause() instanceof Error) {
throw (Error) e.getCause();
}
throw e;
}
}
@Override public String toString() {
return "[wrapper " + method + "]";
}
@Override public int hashCode() {
final int PRIME = 31;
return (PRIME + method.hashCode()) * PRIME + target.hashCode();
}
@Override public boolean equals(Object obj) {
if(this == obj) {
return true;
}
if(obj == null) {
return false;
}
if(getClass() != obj.getClass()) {
return false;
}
final EventHandler other = (EventHandler) obj;
return method.equals(other.method) && target == other.target;
}
}
| 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.
*/
/**
* The EventBus allows publish-subscribe-style communication between components
* without requiring the components to explicitly register with one another
* (and thus be aware of each other). It is designed exclusively to replace
* traditional Java in-process event distribution using explicit registration.
* It is <em>not</em> a general-purpose publish-subscribe system, nor is it
* intended for interprocess communication.
*
* <p>See the Guava User Guide article on <a href=
* "http://code.google.com/p/guava-libraries/wiki/EventBusExplained">
* {@code EventBus}</a>.
*
* <h2>One-Minute Guide</h2>
*
* Converting an existing EventListener-based system to use the EventBus is
* easy.
*
* <h3>For Listeners</h3>
* To listen for a specific flavor of event (say, a CustomerChangeEvent)...
* <ul>
* <li><strong>...in traditional Java events:</strong> implement an interface
* defined with the event — such as CustomerChangeEventListener.</li>
* <li><strong>...with EventBus:</strong> create a method that accepts
* CustomerChangeEvent as its sole argument, and mark it with the
* {@link com.google.common.eventbus.Subscribe} annotation.</li>
* </ul>
*
* <p>To register your listener methods with the event producers...
* <ul>
* <li><strong>...in traditional Java events:</strong> pass your object to each
* producer's {@code registerCustomerChangeEventListener} method. These
* methods are rarely defined in common interfaces, so in addition to
* knowing every possible producer, you must also know its type.</li>
* <li><strong>...with EventBus:</strong> pass your object to the
* {@link com.google.common.eventbus.EventBus#register(Object)} method on an
* EventBus. You'll need to
* make sure that your object shares an EventBus instance with the event
* producers.</li>
* </ul>
*
* <p>To listen for a common event supertype (such as EventObject or Object)...
* <ul>
* <li><strong>...in traditional Java events:</strong> not easy.</li>
* <li><strong>...with EventBus:</strong> events are automatically dispatched to
* listeners of any supertype, allowing listeners for interface types
* or "wildcard listeners" for Object.</li>
* </ul>
*
* <p>To listen for and detect events that were dispatched without listeners...
* <ul>
* <li><strong>...in traditional Java events:</strong> add code to each
* event-dispatching method (perhaps using AOP).</li>
* <li><strong>...with EventBus:</strong> subscribe to {@link
* com.google.common.eventbus.DeadEvent}. The
* EventBus will notify you of any events that were posted but not
* delivered. (Handy for debugging.)</li>
* </ul>
*
* <h3>For Producers</h3>
* To keep track of listeners to your events...
* <ul>
* <li><strong>...in traditional Java events:</strong> write code to manage
* a list of listeners to your object, including synchronization, or use a
* utility class like EventListenerList.</li>
* <li><strong>...with EventBus:</strong> EventBus does this for you.</li>
* </ul>
*
* <p>To dispatch an event to listeners...
* <ul>
* <li><strong>...in traditional Java events:</strong> write a method to
* dispatch events to each event listener, including error isolation and
* (if desired) asynchronicity.</li>
* <li><strong>...with EventBus:</strong> pass the event object to an EventBus's
* {@link com.google.common.eventbus.EventBus#post(Object)} method.</li>
* </ul>
*
* <h2>Glossary</h2>
*
* The EventBus system and code use the following terms to discuss event
* distribution:
* <dl>
* <dt>Event</dt><dd>Any object that may be <em>posted</em> to a bus.</dd>
* <dt>Subscribing</dt><dd>The act of registering a <em>listener</em> with an
* EventBus, so that its <em>handler methods</em> will receive events.</dd>
* <dt>Listener</dt><dd>An object that wishes to receive events, by exposing
* <em>handler methods</em>.</dt>
* <dt>Handler method</dt><dd>A public method that the EventBus should use to
* deliver <em>posted</em> events. Handler methods are marked by the
* {@link com.google.common.eventbus.Subscribe} annotation.</dd>
* <dt>Posting an event</dt><dd>Making the event available to any
* <em>listeners</em> through the EventBus.</dt>
* </dl>
*
* <h2>FAQ</h2>
* <h3>Why must I create my own Event Bus, rather than using a singleton?</h3>
*
* The Event Bus doesn't specify how you use it; there's nothing stopping your
* application from having separate EventBus instances for each component, or
* using separate instances to separate events by context or topic. This also
* makes it trivial to set up and tear down EventBus objects in your tests.
*
* <p>Of course, if you'd like to have a process-wide EventBus singleton,
* there's nothing stopping you from doing it that way. Simply have your
* container (such as Guice) create the EventBus as a singleton at global scope
* (or stash it in a static field, if you're into that sort of thing).
*
* <p>In short, the EventBus is not a singleton because we'd rather not make
* that decision for you. Use it how you like.
*
* <h3>Can I unregister a listener from the Event Bus?</h3>
* Currently, no -- a listener registered with an EventBus instance will
* continue to receive events until the EventBus itself is disposed.
*
* <p>In the apps using EventBus so far, this has not been a problem:
* <ul>
* <li>Most listeners are registered on startup or lazy initialization, and
* persist for the life of the application.
* <li>Scope-specific EventBus instances can handle temporary event
* distribution (e.g. distributing events among request-scoped objects)
* <li>For testing, EventBus instances can be easily created and thrown away,
* removing the need for explicit unregistration.
* </ul>
*
* <h3>Why use an annotation to mark handler methods, rather than requiring the
* listener to implement an interface?</h3>
* We feel that the Event Bus's {@code @Subscribe} annotation conveys your
* intentions just as explicitly as implementing an interface (or perhaps more
* so), while leaving you free to place event handler methods wherever you wish
* and give them intention-revealing names.
*
* <p>Traditional Java Events use a listener interface which typically sports
* only a handful of methods -- typically one. This has a number of
* disadvantages:
* <ul>
* <li>Any one class can only implement a single response to a given event.
* <li>Listener interface methods may conflict.
* <li>The method must be named after the event (e.g. {@code
* handleChangeEvent}), rather than its purpose (e.g. {@code
* recordChangeInJournal}).
* <li>Each event usually has its own interface, without a common parent
* interface for a family of events (e.g. all UI events).
* </ul>
*
* <p>The difficulties in implementing this cleanly has given rise to a pattern,
* particularly common in Swing apps, of using tiny anonymous classes to
* implement event listener interfaces.
*
* <p>Compare these two cases: <pre>
* class ChangeRecorder {
* void setCustomer(Customer cust) {
* cust.addChangeListener(new ChangeListener() {
* void customerChanged(ChangeEvent e) {
* recordChange(e.getChange());
* }
* };
* }
* }
*
* // Class is typically registered by the container.
* class EventBusChangeRecorder {
* @Subscribe void recordCustomerChange(ChangeEvent e) {
* recordChange(e.getChange());
* }
* }</pre>
*
* The intent is actually clearer in the second case: there's less noise code,
* and the event handler has a clear and meaningful name.
*
* <h3>What about a generic {@code Handler<T>} interface?</h3>
* Some have proposed a generic {@code Handler<T>} interface for EventBus
* listeners. This runs into issues with Java's use of type erasure, not to
* mention problems in usability.
*
* <p>Let's say the interface looked something like the following: <pre> {@code
* interface Handler<T> {
* void handleEvent(T event);
* }}</pre>
*
* Due to erasure, no single class can implement a generic interface more than
* once with different type parameters. This is a giant step backwards from
* traditional Java Events, where even if {@code actionPerformed} and {@code
* keyPressed} aren't very meaningful names, at least you can implement both
* methods!
*
* <h3>Doesn't EventBus destroy static typing and eliminate automated
* refactoring support?</h3>
* Some have freaked out about EventBus's {@code register(Object)} and {@code
* post(Object)} methods' use of the {@code Object} type.
*
* <p>{@code Object} is used here for a good reason: the Event Bus library
* places no restrictions on the types of either your event listeners (as in
* {@code register(Object)}) or the events themselves (in {@code post(Object)}).
*
* <p>Event handler methods, on the other hand, must explicitly declare their
* argument type -- the type of event desired (or one of its supertypes). Thus,
* searching for references to an event class will instantly find all handler
* methods for that event, and renaming the type will affect all handler methods
* within view of your IDE (and any code that creates the event).
*
* <p>It's true that you can rename your {@code @Subscribed} event handler
* methods at will; Event Bus will not stop this or do anything to propagate the
* rename because, to Event Bus, the names of your handler methods are
* irrelevant. Test code that calls the methods directly, of course, will be
* affected by your renaming -- but that's what your refactoring tools are for.
*
* <h3>What happens if I {@code register} a listener without any handler
* methods?</h3>
* Nothing at all.
*
* <p>The Event Bus was designed to integrate with containers and module
* systems, with Guice as the prototypical example. In these cases, it's
* convenient to have the container/factory/environment pass <i>every</i>
* created object to an EventBus's {@code register(Object)} method.
*
* <p>This way, any object created by the container/factory/environment can
* hook into the system's event model simply by exposing handler methods.
*
* <h3>What Event Bus problems can be detected at compile time?</h3>
* Any problem that can be unambiguously detected by Java's type system. For
* example, defining a handler method for a nonexistent event type.
*
* <h3>What Event Bus problems can be detected immediately at registration?</h3>
* Immediately upon invoking {@code register(Object)} , the listener being
* registered is checked for the <i>well-formedness</i> of its handler methods.
* Specifically, any methods marked with {@code @Subscribe} must take only a
* single argument.
*
* <p>Any violations of this rule will cause an {@code IllegalArgumentException}
* to be thrown.
*
* <p>(This check could be moved to compile-time using APT, a solution we're
* researching.)
*
* <h3>What Event Bus problems may only be detected later, at runtime?</h3>
* If a component posts events with no registered listeners, it <i>may</i>
* indicate an error (typically an indication that you missed a
* {@code @Subscribe} annotation, or that the listening component is not loaded).
*
* <p>(Note that this is <i>not necessarily</i> indicative of a problem. There
* are many cases where an application will deliberately ignore a posted event,
* particularly if the event is coming from code you don't control.)
*
* <p>To handle such events, register a handler method for the {@code DeadEvent}
* class. Whenever EventBus receives an event with no registered handlers, it
* will turn it into a {@code DeadEvent} and pass it your way -- allowing you to
* log it or otherwise recover.
*
* <h3>How do I test event listeners and their handler methods?</h3>
* Because handler methods on your listener classes are normal methods, you can
* simply call them from your test code to simulate the EventBus.
*/
package com.google.common.eventbus;
| 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.eventbus;
import com.google.common.annotations.Beta;
import java.lang.annotation.ElementType;
import java.lang.annotation.Retention;
import java.lang.annotation.RetentionPolicy;
import java.lang.annotation.Target;
/**
* Marks a method as an event handler, as used by
* {@link AnnotatedHandlerFinder} and {@link EventBus}.
*
* <p>The type of event will be indicated by the method's first (and only)
* parameter. If this annotation is applied to methods with zero parameters,
* or more than one parameter, the object containing the method will not be able
* to register for event delivery from the {@link EventBus}.
*
* <p>Unless also annotated with @{@link AllowConcurrentEvents}, event handler
* methods will be invoked serially by each event bus that they are registered
* with.
*
* @author Cliff Biffle
* @since 10.0
*/
@Retention(RetentionPolicy.RUNTIME)
@Target(ElementType.METHOD)
@Beta
public @interface Subscribe {
}
| 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.eventbus;
import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;
/**
* Wraps a single-argument 'handler' method on a specific object, and ensures
* that only one thread may enter the method at a time.
*
* <p>Beyond synchronization, this class behaves identically to
* {@link EventHandler}.
*
* @author Cliff Biffle
*/
class SynchronizedEventHandler extends EventHandler {
/**
* Creates a new SynchronizedEventHandler to wrap {@code method} on
* {@code target}.
*
* @param target object to which the method applies.
* @param method handler method.
*/
public SynchronizedEventHandler(Object target, Method method) {
super(target, method);
}
@Override public synchronized void handleEvent(Object event)
throws InvocationTargetException {
super.handleEvent(event);
}
}
| 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.eventbus;
import com.google.common.annotations.Beta;
import java.util.concurrent.ConcurrentLinkedQueue;
import java.util.concurrent.Executor;
/**
* An {@link EventBus} that takes the Executor of your choice and uses it to
* dispatch events, allowing dispatch to occur asynchronously.
*
* @author Cliff Biffle
* @since 10.0
*/
@Beta
public class AsyncEventBus extends EventBus {
private final Executor executor;
/** the queue of events is shared across all threads */
private final ConcurrentLinkedQueue<EventWithHandler> eventsToDispatch =
new ConcurrentLinkedQueue<EventWithHandler>();
/**
* Creates a new AsyncEventBus that will use {@code executor} to dispatch
* events. Assigns {@code identifier} as the bus's name for logging purposes.
*
* @param identifier short name for the bus, for logging purposes.
* @param executor Executor to use to dispatch events. It is the caller's
* responsibility to shut down the executor after the last event has
* been posted to this event bus.
*/
public AsyncEventBus(String identifier, Executor executor) {
super(identifier);
this.executor = executor;
}
/**
* Creates a new AsyncEventBus that will use {@code executor} to dispatch
* events.
*
* @param executor Executor to use to dispatch events. It is the caller's
* responsibility to shut down the executor after the last event has
* been posted to this event bus.
*/
public AsyncEventBus(Executor executor) {
this.executor = executor;
}
@Override
protected void enqueueEvent(Object event, EventHandler handler) {
eventsToDispatch.offer(new EventWithHandler(event, handler));
}
/**
* Dispatch {@code events} in the order they were posted, regardless of
* the posting thread.
*/
@Override
protected void dispatchQueuedEvents() {
while (true) {
EventWithHandler eventWithHandler = eventsToDispatch.poll();
if (eventWithHandler == null) {
break;
}
dispatch(eventWithHandler.event, eventWithHandler.handler);
}
}
/**
* Calls the {@link #executor} to dispatch {@code event} to {@code handler}.
*/
@Override
protected void dispatch(final Object event, final EventHandler handler) {
executor.execute(new Runnable() {
@Override
@SuppressWarnings("synthetic-access")
public void run() {
AsyncEventBus.super.dispatch(event, handler);
}
});
}
}
| 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.net;
import com.google.common.annotations.Beta;
import com.google.common.annotations.VisibleForTesting;
import com.google.common.base.Preconditions;
import com.google.common.io.ByteStreams;
import com.google.common.primitives.Ints;
import java.net.Inet4Address;
import java.net.Inet6Address;
import java.net.InetAddress;
import java.net.UnknownHostException;
import java.nio.ByteBuffer;
import java.util.Arrays;
import javax.annotation.Nullable;
/**
* Static utility methods pertaining to {@link InetAddress} instances.
*
* <p><b>Important note:</b> Unlike {@code InetAddress.getByName()}, the
* methods of this class never cause DNS services to be accessed. For
* this reason, you should prefer these methods as much as possible over
* their JDK equivalents whenever you are expecting to handle only
* IP address string literals -- there is no blocking DNS penalty for a
* malformed string.
*
* <p>This class hooks into the {@code sun.net.util.IPAddressUtil} class
* to make use of the {@code textToNumericFormatV4} and
* {@code textToNumericFormatV6} methods directly as a means to avoid
* accidentally traversing all nameservices (it can be vitally important
* to avoid, say, blocking on DNS at times).
*
* <p>When dealing with {@link Inet4Address} and {@link Inet6Address}
* objects as byte arrays (vis. {@code InetAddress.getAddress()}) they
* are 4 and 16 bytes in length, respectively, and represent the address
* in network byte order.
*
* <p>Examples of IP addresses and their byte representations:
* <ul>
* <li>The IPv4 loopback address, {@code "127.0.0.1"}.<br/>
* {@code 7f 00 00 01}
*
* <li>The IPv6 loopback address, {@code "::1"}.<br/>
* {@code 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 01}
*
* <li>From the IPv6 reserved documentation prefix ({@code 2001:db8::/32}),
* {@code "2001:db8::1"}.<br/>
* {@code 20 01 0d b8 00 00 00 00 00 00 00 00 00 00 00 01}
*
* <li>An IPv6 "IPv4 compatible" (or "compat") address,
* {@code "::192.168.0.1"}.<br/>
* {@code 00 00 00 00 00 00 00 00 00 00 00 00 c0 a8 00 01}
*
* <li>An IPv6 "IPv4 mapped" address, {@code "::ffff:192.168.0.1"}.<br/>
* {@code 00 00 00 00 00 00 00 00 00 00 ff ff c0 a8 00 01}
* </ul>
*
* <p>A few notes about IPv6 "IPv4 mapped" addresses and their observed
* use in Java.
* <br><br>
* "IPv4 mapped" addresses were originally a representation of IPv4
* addresses for use on an IPv6 socket that could receive both IPv4
* and IPv6 connections (by disabling the {@code IPV6_V6ONLY} socket
* option on an IPv6 socket). Yes, it's confusing. Nevertheless,
* these "mapped" addresses were never supposed to be seen on the
* wire. That assumption was dropped, some say mistakenly, in later
* RFCs with the apparent aim of making IPv4-to-IPv6 transition simpler.
*
* <p>Technically one <i>can</i> create a 128bit IPv6 address with the wire
* format of a "mapped" address, as shown above, and transmit it in an
* IPv6 packet header. However, Java's InetAddress creation methods
* appear to adhere doggedly to the original intent of the "mapped"
* address: all "mapped" addresses return {@link Inet4Address} objects.
*
* <p>For added safety, it is common for IPv6 network operators to filter
* all packets where either the source or destination address appears to
* be a "compat" or "mapped" address. Filtering suggestions usually
* recommend discarding any packets with source or destination addresses
* in the invalid range {@code ::/3}, which includes both of these bizarre
* address formats. For more information on "bogons", including lists
* of IPv6 bogon space, see:
*
* <ul>
* <li><a target="_parent"
* href="http://en.wikipedia.org/wiki/Bogon_filtering"
* >http://en.wikipedia.org/wiki/Bogon_filtering</a>
* <li><a target="_parent"
* href="http://www.cymru.com/Bogons/ipv6.txt"
* >http://www.cymru.com/Bogons/ipv6.txt</a>
* <li><a target="_parent"
* href="http://www.cymru.com/Bogons/v6bogon.html"
* >http://www.cymru.com/Bogons/v6bogon.html</a>
* <li><a target="_parent"
* href="http://www.space.net/~gert/RIPE/ipv6-filters.html"
* >http://www.space.net/~gert/RIPE/ipv6-filters.html</a>
* </ul>
*
* @author Erik Kline
* @since 5.0
*/
@Beta
public final class InetAddresses {
private static final int IPV4_PART_COUNT = 4;
private static final int IPV6_PART_COUNT = 8;
private static final Inet4Address LOOPBACK4 =
(Inet4Address) forString("127.0.0.1");
private static final Inet4Address ANY4 =
(Inet4Address) forString("0.0.0.0");
private InetAddresses() {}
/**
* Returns an {@link Inet4Address}, given a byte array representation
* of the IPv4 address.
*
* @param bytes byte array representing an IPv4 address (should be
* of length 4).
* @return {@link Inet4Address} corresponding to the supplied byte
* array.
* @throws IllegalArgumentException if a valid {@link Inet4Address}
* can not be created.
*/
private static Inet4Address getInet4Address(byte[] bytes) {
Preconditions.checkArgument(bytes.length == 4,
"Byte array has invalid length for an IPv4 address: %s != 4.",
bytes.length);
// Given a 4-byte array, this cast should always succeed.
return (Inet4Address) bytesToInetAddress(bytes);
}
/**
* Returns the {@link InetAddress} having the given string
* representation.
*
* <p>This deliberately avoids all nameservice lookups (e.g. no DNS).
*
* @param ipString {@code String} containing an IPv4 or IPv6 string literal,
* e.g. {@code "192.168.0.1"} or {@code "2001:db8::1"}
* @return {@link InetAddress} representing the argument
* @throws IllegalArgumentException if the argument is not a valid
* IP string literal
*/
public static InetAddress forString(String ipString) {
byte[] addr = ipStringToBytes(ipString);
// The argument was malformed, i.e. not an IP string literal.
if (addr == null) {
throw new IllegalArgumentException(
String.format("'%s' is not an IP string literal.", ipString));
}
return bytesToInetAddress(addr);
}
/**
* Returns {@code true} if the supplied string is a valid IP string
* literal, {@code false} otherwise.
*
* @param ipString {@code String} to evaluated as an IP string literal
* @return {@code true} if the argument is a valid IP string literal
*/
public static boolean isInetAddress(String ipString) {
return ipStringToBytes(ipString) != null;
}
private static byte[] ipStringToBytes(String ipString) {
// Make a first pass to categorize the characters in this string.
boolean hasColon = false;
boolean hasDot = false;
for (int i = 0; i < ipString.length(); i++) {
char c = ipString.charAt(i);
if (c == '.') {
hasDot = true;
} else if (c == ':') {
if (hasDot) {
return null; // Colons must not appear after dots.
}
hasColon = true;
} else if (Character.digit(c, 16) == -1) {
return null; // Everything else must be a decimal or hex digit.
}
}
// Now decide which address family to parse.
if (hasColon) {
if (hasDot) {
ipString = convertDottedQuadToHex(ipString);
if (ipString == null) {
return null;
}
}
return textToNumericFormatV6(ipString);
} else if (hasDot) {
return textToNumericFormatV4(ipString);
}
return null;
}
private static byte[] textToNumericFormatV4(String ipString) {
String[] address = ipString.split("\\.", IPV4_PART_COUNT + 1);
if (address.length != IPV4_PART_COUNT) {
return null;
}
byte[] bytes = new byte[IPV4_PART_COUNT];
try {
for (int i = 0; i < bytes.length; i++) {
bytes[i] = parseOctet(address[i]);
}
} catch (NumberFormatException ex) {
return null;
}
return bytes;
}
private static byte[] textToNumericFormatV6(String ipString) {
// An address can have [2..8] colons, and N colons make N+1 parts.
String[] parts = ipString.split(":", IPV6_PART_COUNT + 2);
if (parts.length < 3 || parts.length > IPV6_PART_COUNT + 1) {
return null;
}
// Disregarding the endpoints, find "::" with nothing in between.
// This indicates that a run of zeroes has been skipped.
int skipIndex = -1;
for (int i = 1; i < parts.length - 1; i++) {
if (parts[i].length() == 0) {
if (skipIndex >= 0) {
return null; // Can't have more than one ::
}
skipIndex = i;
}
}
int partsHi; // Number of parts to copy from above/before the "::"
int partsLo; // Number of parts to copy from below/after the "::"
if (skipIndex >= 0) {
// If we found a "::", then check if it also covers the endpoints.
partsHi = skipIndex;
partsLo = parts.length - skipIndex - 1;
if (parts[0].length() == 0 && --partsHi != 0) {
return null; // ^: requires ^::
}
if (parts[parts.length - 1].length() == 0 && --partsLo != 0) {
return null; // :$ requires ::$
}
} else {
// Otherwise, allocate the entire address to partsHi. The endpoints
// could still be empty, but parseHextet() will check for that.
partsHi = parts.length;
partsLo = 0;
}
// If we found a ::, then we must have skipped at least one part.
// Otherwise, we must have exactly the right number of parts.
int partsSkipped = IPV6_PART_COUNT - (partsHi + partsLo);
if (!(skipIndex >= 0 ? partsSkipped >= 1 : partsSkipped == 0)) {
return null;
}
// Now parse the hextets into a byte array.
ByteBuffer rawBytes = ByteBuffer.allocate(2 * IPV6_PART_COUNT);
try {
for (int i = 0; i < partsHi; i++) {
rawBytes.putShort(parseHextet(parts[i]));
}
for (int i = 0; i < partsSkipped; i++) {
rawBytes.putShort((short) 0);
}
for (int i = partsLo; i > 0; i--) {
rawBytes.putShort(parseHextet(parts[parts.length - i]));
}
} catch (NumberFormatException ex) {
return null;
}
return rawBytes.array();
}
private static String convertDottedQuadToHex(String ipString) {
int lastColon = ipString.lastIndexOf(':');
String initialPart = ipString.substring(0, lastColon + 1);
String dottedQuad = ipString.substring(lastColon + 1);
byte[] quad = textToNumericFormatV4(dottedQuad);
if (quad == null) {
return null;
}
String penultimate = Integer.toHexString(((quad[0] & 0xff) << 8) | (quad[1] & 0xff));
String ultimate = Integer.toHexString(((quad[2] & 0xff) << 8) | (quad[3] & 0xff));
return initialPart + penultimate + ":" + ultimate;
}
private static byte parseOctet(String ipPart) {
// Note: we already verified that this string contains only hex digits.
int octet = Integer.parseInt(ipPart);
// Disallow leading zeroes, because no clear standard exists on
// whether these should be interpreted as decimal or octal.
if (octet > 255 || (ipPart.startsWith("0") && ipPart.length() > 1)) {
throw new NumberFormatException();
}
return (byte) octet;
}
private static short parseHextet(String ipPart) {
// Note: we already verified that this string contains only hex digits.
int hextet = Integer.parseInt(ipPart, 16);
if (hextet > 0xffff) {
throw new NumberFormatException();
}
return (short) hextet;
}
/**
* Convert a byte array into an InetAddress.
*
* {@link InetAddress#getByAddress} is documented as throwing a checked
* exception "if IP address if of illegal length." We replace it with
* an unchecked exception, for use by callers who already know that addr
* is an array of length 4 or 16.
*
* @param addr the raw 4-byte or 16-byte IP address in big-endian order
* @return an InetAddress object created from the raw IP address
*/
private static InetAddress bytesToInetAddress(byte[] addr) {
try {
return InetAddress.getByAddress(addr);
} catch (UnknownHostException e) {
throw new AssertionError(e);
}
}
/**
* Returns the string representation of an {@link InetAddress}.
*
* <p>For IPv4 addresses, this is identical to
* {@link InetAddress#getHostAddress()}, but for IPv6 addresses, the output
* follows <a href="http://tools.ietf.org/html/rfc5952">RFC 5952</a>
* section 4. The main difference is that this method uses "::" for zero
* compression, while Java's version uses the uncompressed form.
*
* <p>This method uses hexadecimal for all IPv6 addresses, including
* IPv4-mapped IPv6 addresses such as "::c000:201". The output does not
* include a Scope ID.
*
* @param ip {@link InetAddress} to be converted to an address string
* @return {@code String} containing the text-formatted IP address
* @since 10.0
*/
public static String toAddrString(InetAddress ip) {
Preconditions.checkNotNull(ip);
if (ip instanceof Inet4Address) {
// For IPv4, Java's formatting is good enough.
return ip.getHostAddress();
}
Preconditions.checkArgument(ip instanceof Inet6Address);
byte[] bytes = ip.getAddress();
int[] hextets = new int[IPV6_PART_COUNT];
for (int i = 0; i < hextets.length; i++) {
hextets[i] = Ints.fromBytes(
(byte) 0, (byte) 0, bytes[2 * i], bytes[2 * i + 1]);
}
compressLongestRunOfZeroes(hextets);
return hextetsToIPv6String(hextets);
}
/**
* Identify and mark the longest run of zeroes in an IPv6 address.
*
* <p>Only runs of two or more hextets are considered. In case of a tie, the
* leftmost run wins. If a qualifying run is found, its hextets are replaced
* by the sentinel value -1.
*
* @param hextets {@code int[]} mutable array of eight 16-bit hextets.
*/
private static void compressLongestRunOfZeroes(int[] hextets) {
int bestRunStart = -1;
int bestRunLength = -1;
int runStart = -1;
for (int i = 0; i < hextets.length + 1; i++) {
if (i < hextets.length && hextets[i] == 0) {
if (runStart < 0) {
runStart = i;
}
} else if (runStart >= 0) {
int runLength = i - runStart;
if (runLength > bestRunLength) {
bestRunStart = runStart;
bestRunLength = runLength;
}
runStart = -1;
}
}
if (bestRunLength >= 2) {
Arrays.fill(hextets, bestRunStart, bestRunStart + bestRunLength, -1);
}
}
/**
* Convert a list of hextets into a human-readable IPv6 address.
*
* <p>In order for "::" compression to work, the input should contain negative
* sentinel values in place of the elided zeroes.
*
* @param hextets {@code int[]} array of eight 16-bit hextets, or -1s.
*/
private static String hextetsToIPv6String(int[] hextets) {
/*
* While scanning the array, handle these state transitions:
* start->num => "num" start->gap => "::"
* num->num => ":num" num->gap => "::"
* gap->num => "num" gap->gap => ""
*/
StringBuilder buf = new StringBuilder(39);
boolean lastWasNumber = false;
for (int i = 0; i < hextets.length; i++) {
boolean thisIsNumber = hextets[i] >= 0;
if (thisIsNumber) {
if (lastWasNumber) {
buf.append(':');
}
buf.append(Integer.toHexString(hextets[i]));
} else {
if (i == 0 || lastWasNumber) {
buf.append("::");
}
}
lastWasNumber = thisIsNumber;
}
return buf.toString();
}
/**
* Returns the string representation of an {@link InetAddress} suitable
* for inclusion in a URI.
*
* <p>For IPv4 addresses, this is identical to
* {@link InetAddress#getHostAddress()}, but for IPv6 addresses it
* compresses zeroes and surrounds the text with square brackets; for example
* {@code "[2001:db8::1]"}.
*
* <p>Per section 3.2.2 of
* <a target="_parent"
* href="http://tools.ietf.org/html/rfc3986#section-3.2.2"
* >http://tools.ietf.org/html/rfc3986</a>,
* a URI containing an IPv6 string literal is of the form
* {@code "http://[2001:db8::1]:8888/index.html"}.
*
* <p>Use of either {@link InetAddresses#toAddrString},
* {@link InetAddress#getHostAddress()}, or this method is recommended over
* {@link InetAddress#toString()} when an IP address string literal is
* desired. This is because {@link InetAddress#toString()} prints the
* hostname and the IP address string joined by a "/".
*
* @param ip {@link InetAddress} to be converted to URI string literal
* @return {@code String} containing URI-safe string literal
*/
public static String toUriString(InetAddress ip) {
if (ip instanceof Inet6Address) {
return "[" + toAddrString(ip) + "]";
}
return toAddrString(ip);
}
/**
* Returns an InetAddress representing the literal IPv4 or IPv6 host
* portion of a URL, encoded in the format specified by RFC 3986 section 3.2.2.
*
* <p>This function is similar to {@link InetAddresses#forString(String)},
* however, it requires that IPv6 addresses are surrounded by square brackets.
*
* <p>This function is the inverse of
* {@link InetAddresses#toUriString(java.net.InetAddress)}.
*
* @param hostAddr A RFC 3986 section 3.2.2 encoded IPv4 or IPv6 address
* @return an InetAddress representing the address in {@code hostAddr}
* @throws IllegalArgumentException if {@code hostAddr} is not a valid
* IPv4 address, or IPv6 address surrounded by square brackets
*/
public static InetAddress forUriString(String hostAddr) {
Preconditions.checkNotNull(hostAddr);
// Decide if this should be an IPv6 or IPv4 address.
String ipString;
int expectBytes;
if (hostAddr.startsWith("[") && hostAddr.endsWith("]")) {
ipString = hostAddr.substring(1, hostAddr.length() - 1);
expectBytes = 16;
} else {
ipString = hostAddr;
expectBytes = 4;
}
// Parse the address, and make sure the length/version is correct.
byte[] addr = ipStringToBytes(ipString);
if (addr == null || addr.length != expectBytes) {
throw new IllegalArgumentException(
String.format("Not a valid URI IP literal: '%s'", hostAddr));
}
return bytesToInetAddress(addr);
}
/**
* Returns {@code true} if the supplied string is a valid URI IP string
* literal, {@code false} otherwise.
*
* @param ipString {@code String} to evaluated as an IP URI host string literal
* @return {@code true} if the argument is a valid IP URI host
*/
public static boolean isUriInetAddress(String ipString) {
try {
forUriString(ipString);
return true;
} catch (IllegalArgumentException e) {
return false;
}
}
/**
* Evaluates whether the argument is an IPv6 "compat" address.
*
* <p>An "IPv4 compatible", or "compat", address is one with 96 leading
* bits of zero, with the remaining 32 bits interpreted as an
* IPv4 address. These are conventionally represented in string
* literals as {@code "::192.168.0.1"}, though {@code "::c0a8:1"} is
* also considered an IPv4 compatible address (and equivalent to
* {@code "::192.168.0.1"}).
*
* <p>For more on IPv4 compatible addresses see section 2.5.5.1 of
* <a target="_parent"
* href="http://tools.ietf.org/html/rfc4291#section-2.5.5.1"
* >http://tools.ietf.org/html/rfc4291</a>
*
* <p>NOTE: This method is different from
* {@link Inet6Address#isIPv4CompatibleAddress} in that it more
* correctly classifies {@code "::"} and {@code "::1"} as
* proper IPv6 addresses (which they are), NOT IPv4 compatible
* addresses (which they are generally NOT considered to be).
*
* @param ip {@link Inet6Address} to be examined for embedded IPv4
* compatible address format
* @return {@code true} if the argument is a valid "compat" address
*/
public static boolean isCompatIPv4Address(Inet6Address ip) {
if (!ip.isIPv4CompatibleAddress()) {
return false;
}
byte[] bytes = ip.getAddress();
if ((bytes[12] == 0) && (bytes[13] == 0) && (bytes[14] == 0)
&& ((bytes[15] == 0) || (bytes[15] == 1))) {
return false;
}
return true;
}
/**
* Returns the IPv4 address embedded in an IPv4 compatible address.
*
* @param ip {@link Inet6Address} to be examined for an embedded
* IPv4 address
* @return {@link Inet4Address} of the embedded IPv4 address
* @throws IllegalArgumentException if the argument is not a valid
* IPv4 compatible address
*/
public static Inet4Address getCompatIPv4Address(Inet6Address ip) {
Preconditions.checkArgument(isCompatIPv4Address(ip),
"Address '%s' is not IPv4-compatible.", toAddrString(ip));
return getInet4Address(copyOfRange(ip.getAddress(), 12, 16));
}
/**
* Evaluates whether the argument is a 6to4 address.
*
* <p>6to4 addresses begin with the {@code "2002::/16"} prefix.
* The next 32 bits are the IPv4 address of the host to which
* IPv6-in-IPv4 tunneled packets should be routed.
*
* <p>For more on 6to4 addresses see section 2 of
* <a target="_parent" href="http://tools.ietf.org/html/rfc3056#section-2"
* >http://tools.ietf.org/html/rfc3056</a>
*
* @param ip {@link Inet6Address} to be examined for 6to4 address
* format
* @return {@code true} if the argument is a 6to4 address
*/
public static boolean is6to4Address(Inet6Address ip) {
byte[] bytes = ip.getAddress();
return (bytes[0] == (byte) 0x20) && (bytes[1] == (byte) 0x02);
}
/**
* Returns the IPv4 address embedded in a 6to4 address.
*
* @param ip {@link Inet6Address} to be examined for embedded IPv4
* in 6to4 address.
* @return {@link Inet4Address} of embedded IPv4 in 6to4 address.
* @throws IllegalArgumentException if the argument is not a valid
* IPv6 6to4 address.
*/
public static Inet4Address get6to4IPv4Address(Inet6Address ip) {
Preconditions.checkArgument(is6to4Address(ip),
"Address '%s' is not a 6to4 address.", toAddrString(ip));
return getInet4Address(copyOfRange(ip.getAddress(), 2, 6));
}
/**
* A simple data class to encapsulate the information to be found in a
* Teredo address.
*
* <p>All of the fields in this class are encoded in various portions
* of the IPv6 address as part of the protocol. More protocols details
* can be found at:
* <a target="_parent" href="http://en.wikipedia.org/wiki/Teredo_tunneling"
* >http://en.wikipedia.org/wiki/Teredo_tunneling</a>.
*
* <p>The RFC can be found here:
* <a target="_parent" href="http://tools.ietf.org/html/rfc4380"
* >http://tools.ietf.org/html/rfc4380</a>.
*
* @since 5.0
*/
@Beta
public static final class TeredoInfo {
private final Inet4Address server;
private final Inet4Address client;
private final int port;
private final int flags;
/**
* Constructs a TeredoInfo instance.
*
* <p>Both server and client can be {@code null}, in which case the
* value {@code "0.0.0.0"} will be assumed.
*
* @throws IllegalArgumentException if either of the {@code port}
* or the {@code flags} arguments are out of range of an
* unsigned short
*/
// TODO: why is this public?
public TeredoInfo(@Nullable Inet4Address server,
@Nullable Inet4Address client,
int port, int flags) {
Preconditions.checkArgument((port >= 0) && (port <= 0xffff),
"port '%s' is out of range (0 <= port <= 0xffff)", port);
Preconditions.checkArgument((flags >= 0) && (flags <= 0xffff),
"flags '%s' is out of range (0 <= flags <= 0xffff)", flags);
if (server != null) {
this.server = server;
} else {
this.server = ANY4;
}
if (client != null) {
this.client = client;
} else {
this.client = ANY4;
}
this.port = port;
this.flags = flags;
}
public Inet4Address getServer() {
return server;
}
public Inet4Address getClient() {
return client;
}
public int getPort() {
return port;
}
public int getFlags() {
return flags;
}
}
/**
* Evaluates whether the argument is a Teredo address.
*
* <p>Teredo addresses begin with the {@code "2001::/32"} prefix.
*
* @param ip {@link Inet6Address} to be examined for Teredo address
* format.
* @return {@code true} if the argument is a Teredo address
*/
public static boolean isTeredoAddress(Inet6Address ip) {
byte[] bytes = ip.getAddress();
return (bytes[0] == (byte) 0x20) && (bytes[1] == (byte) 0x01)
&& (bytes[2] == 0) && (bytes[3] == 0);
}
/**
* Returns the Teredo information embedded in a Teredo address.
*
* @param ip {@link Inet6Address} to be examined for embedded Teredo
* information
* @return extracted {@code TeredoInfo}
* @throws IllegalArgumentException if the argument is not a valid
* IPv6 Teredo address
*/
public static TeredoInfo getTeredoInfo(Inet6Address ip) {
Preconditions.checkArgument(isTeredoAddress(ip),
"Address '%s' is not a Teredo address.", toAddrString(ip));
byte[] bytes = ip.getAddress();
Inet4Address server = getInet4Address(copyOfRange(bytes, 4, 8));
int flags = ByteStreams.newDataInput(bytes, 8).readShort() & 0xffff;
// Teredo obfuscates the mapped client port, per section 4 of the RFC.
int port = ~ByteStreams.newDataInput(bytes, 10).readShort() & 0xffff;
byte[] clientBytes = copyOfRange(bytes, 12, 16);
for (int i = 0; i < clientBytes.length; i++) {
// Teredo obfuscates the mapped client IP, per section 4 of the RFC.
clientBytes[i] = (byte) ~clientBytes[i];
}
Inet4Address client = getInet4Address(clientBytes);
return new TeredoInfo(server, client, port, flags);
}
/**
* Evaluates whether the argument is an ISATAP address.
*
* <p>From RFC 5214: "ISATAP interface identifiers are constructed in
* Modified EUI-64 format [...] by concatenating the 24-bit IANA OUI
* (00-00-5E), the 8-bit hexadecimal value 0xFE, and a 32-bit IPv4
* address in network byte order [...]"
*
* <p>For more on ISATAP addresses see section 6.1 of
* <a target="_parent" href="http://tools.ietf.org/html/rfc5214#section-6.1"
* >http://tools.ietf.org/html/rfc5214</a>
*
* @param ip {@link Inet6Address} to be examined for ISATAP address
* format.
* @return {@code true} if the argument is an ISATAP address
*/
public static boolean isIsatapAddress(Inet6Address ip) {
// If it's a Teredo address with the right port (41217, or 0xa101)
// which would be encoded as 0x5efe then it can't be an ISATAP address.
if (isTeredoAddress(ip)) {
return false;
}
byte[] bytes = ip.getAddress();
if ((bytes[8] | (byte) 0x03) != (byte) 0x03) {
// Verify that high byte of the 64 bit identifier is zero, modulo
// the U/L and G bits, with which we are not concerned.
return false;
}
return (bytes[9] == (byte) 0x00) && (bytes[10] == (byte) 0x5e)
&& (bytes[11] == (byte) 0xfe);
}
/**
* Returns the IPv4 address embedded in an ISATAP address.
*
* @param ip {@link Inet6Address} to be examined for embedded IPv4
* in ISATAP address
* @return {@link Inet4Address} of embedded IPv4 in an ISATAP address
* @throws IllegalArgumentException if the argument is not a valid
* IPv6 ISATAP address
*/
public static Inet4Address getIsatapIPv4Address(Inet6Address ip) {
Preconditions.checkArgument(isIsatapAddress(ip),
"Address '%s' is not an ISATAP address.", toAddrString(ip));
return getInet4Address(copyOfRange(ip.getAddress(), 12, 16));
}
/**
* Examines the Inet6Address to determine if it is an IPv6 address of one
* of the specified address types that contain an embedded IPv4 address.
*
* <p>NOTE: ISATAP addresses are explicitly excluded from this method
* due to their trivial spoofability. With other transition addresses
* spoofing involves (at least) infection of one's BGP routing table.
*
* @param ip {@link Inet6Address} to be examined for embedded IPv4
* client address.
* @return {@code true} if there is an embedded IPv4 client address.
* @since 7.0
*/
public static boolean hasEmbeddedIPv4ClientAddress(Inet6Address ip) {
return isCompatIPv4Address(ip) || is6to4Address(ip) ||
isTeredoAddress(ip);
}
/**
* Examines the Inet6Address to extract the embedded IPv4 client address
* if the InetAddress is an IPv6 address of one of the specified address
* types that contain an embedded IPv4 address.
*
* <p>NOTE: ISATAP addresses are explicitly excluded from this method
* due to their trivial spoofability. With other transition addresses
* spoofing involves (at least) infection of one's BGP routing table.
*
* @param ip {@link Inet6Address} to be examined for embedded IPv4
* client address.
* @return {@link Inet4Address} of embedded IPv4 client address.
* @throws IllegalArgumentException if the argument does not have a valid
* embedded IPv4 address.
*/
public static Inet4Address getEmbeddedIPv4ClientAddress(Inet6Address ip) {
if (isCompatIPv4Address(ip)) {
return getCompatIPv4Address(ip);
}
if (is6to4Address(ip)) {
return get6to4IPv4Address(ip);
}
if (isTeredoAddress(ip)) {
return getTeredoInfo(ip).getClient();
}
throw new IllegalArgumentException(
String.format("'%s' has no embedded IPv4 address.",
toAddrString(ip)));
}
/**
* Evaluates whether the argument is an "IPv4 mapped" IPv6 address.
*
* <p>An "IPv4 mapped" address is anything in the range ::ffff:0:0/96
* (sometimes written as ::ffff:0.0.0.0/96), with the last 32 bits
* interpreted as an IPv4 address.
*
* <p>For more on IPv4 mapped addresses see section 2.5.5.2 of
* <a target="_parent"
* href="http://tools.ietf.org/html/rfc4291#section-2.5.5.2"
* >http://tools.ietf.org/html/rfc4291</a>
*
* <p>Note: This method takes a {@code String} argument because
* {@link InetAddress} automatically collapses mapped addresses to IPv4.
* (It is actually possible to avoid this using one of the obscure
* {@link Inet6Address} methods, but it would be unwise to depend on such
* a poorly-documented feature.)
*
* @param ipString {@code String} to be examined for embedded IPv4-mapped
* IPv6 address format
* @return {@code true} if the argument is a valid "mapped" address
* @since 10.0
*/
public static boolean isMappedIPv4Address(String ipString) {
byte[] bytes = ipStringToBytes(ipString);
if (bytes != null && bytes.length == 16) {
for (int i = 0; i < 10; i++) {
if (bytes[i] != 0) {
return false;
}
}
for (int i = 10; i < 12; i++) {
if (bytes[i] != (byte) 0xff) {
return false;
}
}
return true;
}
return false;
}
/**
* Coerces an IPv6 address into an IPv4 address.
*
* <p>HACK: As long as applications continue to use IPv4 addresses for
* indexing into tables, accounting, et cetera, it may be necessary to
* <b>coerce</b> IPv6 addresses into IPv4 addresses. This function does
* so by hashing the upper 64 bits into {@code 224.0.0.0/3}
* (64 bits into 29 bits).
*
* <p>A "coerced" IPv4 address is equivalent to itself.
*
* <p>NOTE: This function is failsafe for security purposes: ALL IPv6
* addresses (except localhost (::1)) are hashed to avoid the security
* risk associated with extracting an embedded IPv4 address that might
* permit elevated privileges.
*
* @param ip {@link InetAddress} to "coerce"
* @return {@link Inet4Address} represented "coerced" address
* @since 7.0
*/
public static Inet4Address getCoercedIPv4Address(InetAddress ip) {
if (ip instanceof Inet4Address) {
return (Inet4Address) ip;
}
// Special cases:
byte[] bytes = ip.getAddress();
boolean leadingBytesOfZero = true;
for (int i = 0; i < 15; ++i) {
if (bytes[i] != 0) {
leadingBytesOfZero = false;
break;
}
}
if (leadingBytesOfZero && (bytes[15] == 1)) {
return LOOPBACK4; // ::1
} else if (leadingBytesOfZero && (bytes[15] == 0)) {
return ANY4; // ::0
}
Inet6Address ip6 = (Inet6Address) ip;
long addressAsLong = 0;
if (hasEmbeddedIPv4ClientAddress(ip6)) {
addressAsLong = getEmbeddedIPv4ClientAddress(ip6).hashCode();
} else {
// Just extract the high 64 bits (assuming the rest is user-modifiable).
addressAsLong = ByteBuffer.wrap(ip6.getAddress(), 0, 8).getLong();
}
// Many strategies for hashing are possible. This might suffice for now.
int coercedHash = hash64To32(addressAsLong);
// Squash into 224/4 Multicast and 240/4 Reserved space (i.e. 224/3).
coercedHash |= 0xe0000000;
// Fixup to avoid some "illegal" values. Currently the only potential
// illegal value is 255.255.255.255.
if (coercedHash == 0xffffffff) {
coercedHash = 0xfffffffe;
}
return getInet4Address(Ints.toByteArray(coercedHash));
}
/**
* Returns an {@code int} hash of a 64-bit long.
*
* This comes from http://www.concentric.net/~ttwang/tech/inthash.htm
*
* This hash gives no guarantees on the cryptographic suitability nor the
* quality of randomness produced, and the mapping may change in the future.
*
* @param key A 64-bit number to hash
* @return {@code int} the input hashed into 32 bits
*/
@VisibleForTesting static int hash64To32(long key) {
key = (~key) + (key << 18);
key = key ^ (key >>> 31);
key = key * 21;
key = key ^ (key >>> 11);
key = key + (key << 6);
key = key ^ (key >>> 22);
return (int) key;
}
/**
* Returns an integer representing an IPv4 address regardless of
* whether the supplied argument is an IPv4 address or not.
*
* <p>IPv6 addresses are <b>coerced</b> to IPv4 addresses before being
* converted to integers.
*
* <p>As long as there are applications that assume that all IP addresses
* are IPv4 addresses and can therefore be converted safely to integers
* (for whatever purpose) this function can be used to handle IPv6
* addresses as well until the application is suitably fixed.
*
* <p>NOTE: an IPv6 address coerced to an IPv4 address can only be used
* for such purposes as rudimentary identification or indexing into a
* collection of real {@link InetAddress}es. They cannot be used as
* real addresses for the purposes of network communication.
*
* @param ip {@link InetAddress} to convert
* @return {@code int}, "coerced" if ip is not an IPv4 address
* @since 7.0
*/
public static int coerceToInteger(InetAddress ip) {
return ByteStreams.newDataInput(getCoercedIPv4Address(ip).getAddress()).readInt();
}
/**
* Returns an Inet4Address having the integer value specified by
* the argument.
*
* @param address {@code int}, the 32bit integer address to be converted
* @return {@link Inet4Address} equivalent of the argument
*/
public static Inet4Address fromInteger(int address) {
return getInet4Address(Ints.toByteArray(address));
}
/**
* Returns an address from a <b>little-endian ordered</b> byte array
* (the opposite of what {@link InetAddress#getByAddress} expects).
*
* <p>IPv4 address byte array must be 4 bytes long and IPv6 byte array
* must be 16 bytes long.
*
* @param addr the raw IP address in little-endian byte order
* @return an InetAddress object created from the raw IP address
* @throws UnknownHostException if IP address is of illegal length
*/
public static InetAddress fromLittleEndianByteArray(byte[] addr)
throws UnknownHostException {
byte[] reversed = new byte[addr.length];
for (int i = 0; i < addr.length; i++) {
reversed[i] = addr[addr.length - i - 1];
}
return InetAddress.getByAddress(reversed);
}
/**
* Returns a new InetAddress that is one more than the passed in address.
* This method works for both IPv4 and IPv6 addresses.
*
* @param address the InetAddress to increment
* @return a new InetAddress that is one more than the passed in address.
* @throws IllegalArgumentException if InetAddress is at the end of its
* range.
* @since 10.0
*/
public static InetAddress increment(InetAddress address) {
byte[] addr = address.getAddress();
int i = addr.length - 1;
while (i >= 0 && addr[i] == (byte) 0xff) {
addr[i] = 0;
i--;
}
Preconditions.checkArgument(i >= 0, "Incrementing %s would wrap.", address);
addr[i]++;
return bytesToInetAddress(addr);
}
/**
* Returns true if the InetAddress is either 255.255.255.255 for IPv4 or
* ffff:ffff:ffff:ffff:ffff:ffff:ffff:ffff for IPv6.
*
* @return true if the InetAddress is either 255.255.255.255 for IPv4 or
* ffff:ffff:ffff:ffff:ffff:ffff:ffff:ffff for IPv6.
* @since 10.0
*/
public static boolean isMaximum(InetAddress address) {
byte[] addr = address.getAddress();
for (int i = 0; i < addr.length; i++) {
if (addr[i] != (byte) 0xff) {
return false;
}
}
return true;
}
/**
* This method emulates the Java 6 method
* {@code Arrays.copyOfRange(byte, int, int)}, which is not available in
* Java 5, and thus cannot be used in Guava code.
*/
private static byte[] copyOfRange(byte[] original, int from, int to) {
Preconditions.checkNotNull(original);
int end = Math.min(to, original.length);
byte[] result = new byte[to - from];
System.arraycopy(original, from, result, 0, end - from);
return result;
}
}
| 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.net;
import com.google.common.annotations.Beta;
import com.google.common.base.Preconditions;
import java.net.InetAddress;
import java.text.ParseException;
import javax.annotation.Nullable;
/**
* A syntactically valid host specifier, suitable for use in a URI.
* This may be either a numeric IP address in IPv4 or IPv6 notation, or a
* domain name.
*
* <p>Because this class is intended to represent host specifiers which can
* reasonably be used in a URI, the domain name case is further restricted to
* include only those domain names which end in a recognized public suffix; see
* {@link InternetDomainName#isPublicSuffix()} for details.
*
* <p>Note that no network lookups are performed by any {@code HostSpecifier}
* methods. No attempt is made to verify that a provided specifier corresponds
* to a real or accessible host. Only syntactic and pattern-based checks are
* performed.
*
* <p>If you know that a given string represents a numeric IP address, use
* {@link InetAddresses} to obtain and manipulate a
* {@link java.net.InetAddress} instance from it rather than using this class.
* Similarly, if you know that a given string represents a domain name, use
* {@link InternetDomainName} rather than this class.
*
* @author Craig Berry
* @since 5.0
*/
@Beta
public final class HostSpecifier {
private final String canonicalForm;
private HostSpecifier(String canonicalForm) {
this.canonicalForm = canonicalForm;
}
/**
* Returns a {@code HostSpecifier} built from the provided {@code specifier},
* which is already known to be valid. If the {@code specifier} might be
* invalid, use {@link #from(String)} instead.
*
* <p>The specifier must be in one of these formats:
* <ul>
* <li>A domain name, like {@code google.com}
* <li>A IPv4 address string, like {@code 127.0.0.1}
* <li>An IPv6 address string with or without brackets, like
* {@code [2001:db8::1]} or {@code 2001:db8::1}
* </ul>
*
* @throws IllegalArgumentException if the specifier is not valid.
*/
public static HostSpecifier fromValid(String specifier) {
// Verify that no port was specified, and strip optional brackets from
// IPv6 literals.
final HostAndPort parsedHost = HostAndPort.fromString(specifier);
Preconditions.checkArgument(!parsedHost.hasPort());
final String host = parsedHost.getHostText();
// Try to interpret the specifier as an IP address. Note we build
// the address rather than using the .is* methods because we want to
// use InetAddresses.toUriString to convert the result to a string in
// canonical form.
InetAddress addr = null;
try {
addr = InetAddresses.forString(host);
} catch (IllegalArgumentException e) {
// It is not an IPv4 or IPv6 literal
}
if (addr != null) {
return new HostSpecifier(InetAddresses.toUriString(addr));
}
// It is not any kind of IP address; must be a domain name or invalid.
// TODO(user): different versions of this for different factories?
final InternetDomainName domain = InternetDomainName.from(host);
if (domain.hasPublicSuffix()) {
return new HostSpecifier(domain.name());
}
throw new IllegalArgumentException(
"Domain name does not have a recognized public suffix: " + host);
}
/**
* Attempts to return a {@code HostSpecifier} for the given string, throwing
* an exception if parsing fails. Always use this method in preference to
* {@link #fromValid(String)} for a specifier that is not already known to be
* valid.
*
* @throws ParseException if the specifier is not valid.
*/
public static HostSpecifier from(String specifier)
throws ParseException {
try {
return fromValid(specifier);
} catch (IllegalArgumentException e) {
// Since the IAE can originate at several different points inside
// fromValid(), we implement this method in terms of that one rather
// than the reverse.
ParseException parseException =
new ParseException("Invalid host specifier: " + specifier, 0);
parseException.initCause(e);
throw parseException;
}
}
/**
* Determines whether {@code specifier} represents a valid
* {@link HostSpecifier} as described in the documentation for
* {@link #fromValid(String)}.
*/
public static boolean isValid(String specifier) {
try {
fromValid(specifier);
return true;
} catch (IllegalArgumentException e) {
return false;
}
}
@Override
public boolean equals(@Nullable Object other) {
if (this == other) {
return true;
}
if (other instanceof HostSpecifier) {
final HostSpecifier that = (HostSpecifier) other;
return this.canonicalForm.equals(that.canonicalForm);
}
return false;
}
@Override
public int hashCode() {
return canonicalForm.hashCode();
}
/**
* Returns a string representation of the host specifier suitable for
* inclusion in a URI. If the host specifier is a domain name, the
* string will be normalized to all lower case. If the specifier was
* an IPv6 address without brackets, brackets are added so that the
* result will be usable in the host part of a URI.
*/
@Override
public String toString() {
return canonicalForm;
}
}
| 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.
*/
/**
* This package contains utility methods and classes for working with net
* addresses (numeric IP and domain names).
*
* <p>This package is a part of the open-source
* <a href="http://guava-libraries.googlecode.com">Guava libraries</a>.
*
* @author Craig Berry
*/
@ParametersAreNonnullByDefault
package com.google.common.net;
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.net;
import com.google.common.annotations.Beta;
import com.google.common.annotations.GwtCompatible;
/**
* Contains constant definitions for the HTTP header field names. See:
* <ul>
* <li><a href="http://www.ietf.org/rfc/rfc2109.txt">RFC 2109</a>
* <li><a href="http://www.ietf.org/rfc/rfc2183.txt">RFC 2183</a>
* <li><a href="http://www.ietf.org/rfc/rfc2616.txt">RFC 2616</a>
* <li><a href="http://www.ietf.org/rfc/rfc2965.txt">RFC 2965</a>
* <li><a href="http://www.ietf.org/rfc/rfc5988.txt">RFC 5988</a>
* </ul>
*
* @author Kurt Alfred Kluever
* @since 11.0
*/
@Beta
@GwtCompatible
public final class HttpHeaders {
private HttpHeaders() {}
// HTTP Request and Response header fields
/** The HTTP Cache-Control header field name. */
public static final String CACHE_CONTROL = "Cache-Control";
/** The HTTP Content-Length header field name. */
public static final String CONTENT_LENGTH = "Content-Length";
/** The HTTP Content-Type header field name. */
public static final String CONTENT_TYPE = "Content-Type";
/** The HTTP Date header field name. */
public static final String DATE = "Date";
/** The HTTP Pragma header field name. */
public static final String PRAGMA = "Pragma";
/** The HTTP Via header field name. */
public static final String VIA = "Via";
/** The HTTP Warning header field name. */
public static final String WARNING = "Warning";
// HTTP Request header fields
/** The HTTP Accept header field name. */
public static final String ACCEPT = "Accept";
/** The HTTP Accept-Charset header field name. */
public static final String ACCEPT_CHARSET = "Accept-Charset";
/** The HTTP Accept-Encoding header field name. */
public static final String ACCEPT_ENCODING = "Accept-Encoding";
/** The HTTP Accept-Language header field name. */
public static final String ACCEPT_LANGUAGE = "Accept-Language";
/** The HTTP Access-Control-Request-Headers header field name. */
public static final String ACCESS_CONTROL_REQUEST_HEADERS = "Access-Control-Request-Headers";
/** The HTTP Access-Control-Request-Method header field name. */
public static final String ACCESS_CONTROL_REQUEST_METHOD = "Access-Control-Request-Method";
/** The HTTP Authorization header field name. */
public static final String AUTHORIZATION = "Authorization";
/** The HTTP Connection header field name. */
public static final String CONNECTION = "Connection";
/** The HTTP Cookie header field name. */
public static final String COOKIE = "Cookie";
/** The HTTP Expect header field name. */
public static final String EXPECT = "Expect";
/** The HTTP From header field name. */
public static final String FROM = "From";
/** The HTTP Host header field name. */
public static final String HOST = "Host";
/** The HTTP If-Match header field name. */
public static final String IF_MATCH = "If-Match";
/** The HTTP If-Modified-Since header field name. */
public static final String IF_MODIFIED_SINCE = "If-Modified-Since";
/** The HTTP If-None-Match header field name. */
public static final String IF_NONE_MATCH = "If-None-Match";
/** The HTTP If-Range header field name. */
public static final String IF_RANGE = "If-Range";
/** The HTTP If-Unmodified-Since header field name. */
public static final String IF_UNMODIFIED_SINCE = "If-Unmodified-Since";
/** The HTTP Last-Event-ID header field name. */
public static final String LAST_EVENT_ID = "Last-Event-ID";
/** The HTTP Max-Forwards header field name. */
public static final String MAX_FORWARDS = "Max-Forwards";
/** The HTTP Origin header field name. */
public static final String ORIGIN = "Origin";
/** The HTTP Proxy-Authorization header field name. */
public static final String PROXY_AUTHORIZATION = "Proxy-Authorization";
/** The HTTP Range header field name. */
public static final String RANGE = "Range";
/** The HTTP Referer header field name. */
public static final String REFERER = "Referer";
/** The HTTP TE header field name. */
public static final String TE = "TE";
/** The HTTP Upgrade header field name. */
public static final String UPGRADE = "Upgrade";
/** The HTTP User-Agent header field name. */
public static final String USER_AGENT = "User-Agent";
// HTTP Response header fields
/** The HTTP Accept-Ranges header field name. */
public static final String ACCEPT_RANGES = "Accept-Ranges";
/** The HTTP Access-Control-Allow-Headers header field name. */
public static final String ACCESS_CONTROL_ALLOW_HEADERS = "Access-Control-Allow-Headers";
/** The HTTP Access-Control-Allow-Methods header field name. */
public static final String ACCESS_CONTROL_ALLOW_METHODS = "Access-Control-Allow-Methods";
/** The HTTP Access-Control-Allow-Origin header field name. */
public static final String ACCESS_CONTROL_ALLOW_ORIGIN = "Access-Control-Allow-Origin";
/** The HTTP Access-Control-Allow-Credentials header field name. */
public static final String ACCESS_CONTROL_ALLOW_CREDENTIALS = "Access-Control-Allow-Credentials";
/** The HTTP Access-Control-Expose-Headers header field name. */
public static final String ACCESS_CONTROL_EXPOSE_HEADERS = "Access-Control-Expose-Headers";
/** The HTTP Access-Control-Max-Age header field name. */
public static final String ACCESS_CONTROL_MAX_AGE = "Access-Control-Max-Age";
/** The HTTP Age header field name. */
public static final String AGE = "Age";
/** The HTTP Allow header field name. */
public static final String ALLOW = "Allow";
/** The HTTP Content-Disposition header field name. */
public static final String CONTENT_DISPOSITION = "Content-Disposition";
/** The HTTP Content-Encoding header field name. */
public static final String CONTENT_ENCODING = "Content-Encoding";
/** The HTTP Content-Language header field name. */
public static final String CONTENT_LANGUAGE = "Content-Language";
/** The HTTP Content-Location header field name. */
public static final String CONTENT_LOCATION = "Content-Location";
/** The HTTP Content-MD5 header field name. */
public static final String CONTENT_MD5 = "Content-MD5";
/** The HTTP Content-Range header field name. */
public static final String CONTENT_RANGE = "Content-Range";
/** The HTTP ETag header field name. */
public static final String ETAG = "ETag";
/** The HTTP Expires header field name. */
public static final String EXPIRES = "Expires";
/** The HTTP Last-Modified header field name. */
public static final String LAST_MODIFIED = "Last-Modified";
/** The HTTP Link header field name. */
public static final String LINK = "Link";
/** The HTTP Location header field name. */
public static final String LOCATION = "Location";
/** The HTTP P3P header field name. Limited browser support. */
public static final String P3P = "P3P";
/** The HTTP Proxy-Authenticate header field name. */
public static final String PROXY_AUTHENTICATE = "Proxy-Authenticate";
/** The HTTP Refresh header field name. Non-standard header supported by most browsers. */
public static final String REFRESH = "Refresh";
/** The HTTP Retry-After header field name. */
public static final String RETRY_AFTER = "Retry-After";
/** The HTTP Server header field name. */
public static final String SERVER = "Server";
/** The HTTP Set-Cookie header field name. */
public static final String SET_COOKIE = "Set-Cookie";
/** The HTTP Set-Cookie2 header field name. */
public static final String SET_COOKIE2 = "Set-Cookie2";
/** The HTTP Trailer header field name. */
public static final String TRAILER = "Trailer";
/** The HTTP Transfer-Encoding header field name. */
public static final String TRANSFER_ENCODING = "Transfer-Encoding";
/** The HTTP Vary header field name. */
public static final String VARY = "Vary";
/** The HTTP WWW-Authenticate header field name. */
public static final String WWW_AUTHENTICATE = "WWW-Authenticate";
// Common, non-standard HTTP header fields
/** The HTTP DNT header field name. */
public static final String DNT = "DNT";
/** The HTTP X-Content-Type-Options header field name. */
public static final String X_CONTENT_TYPE_OPTIONS = "X-Content-Type-Options";
/** The HTTP X-Do-Not-Track header field name. */
public static final String X_DO_NOT_TRACK = "X-Do-Not-Track";
/** The HTTP X-Forwarded-For header field name. */
public static final String X_FORWARDED_FOR = "X-Forwarded-For";
/** The HTTP X-Forwarded-Proto header field name. */
public static final String X_FORWARDED_PROTO = "X-Forwarded-Proto";
/** The HTTP X-Frame-Options header field name. */
public static final String X_FRAME_OPTIONS = "X-Frame-Options";
/** The HTTP X-Powered-By header field name. */
public static final String X_POWERED_BY = "X-Powered-By";
/** The HTTP X-Requested-With header field name. */
public static final String X_REQUESTED_WITH = "X-Requested-With";
/** The HTTP X-User-IP header field name. */
public static final String X_USER_IP = "X-User-IP";
/** The HTTP X-XSS-Protection header field name. */
public static final String X_XSS_PROTECTION = "X-XSS-Protection";
}
| 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.net;
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.Ascii;
import com.google.common.base.CharMatcher;
import com.google.common.base.Joiner;
import com.google.common.base.Objects;
import com.google.common.base.Splitter;
import com.google.common.collect.ImmutableList;
import java.util.List;
import javax.annotation.Nullable;
/**
* An immutable well-formed internet domain name, such as {@code com} or {@code
* foo.co.uk}. Only syntactic analysis is performed; no DNS lookups or other
* network interactions take place. Thus there is no guarantee that the domain
* actually exists on the internet.
*
* <p>One common use of this class is to determine whether a given string is
* likely to represent an addressable domain on the web -- that is, for a
* candidate string {@code "xxx"}, might browsing to {@code "http://xxx/"}
* result in a webpage being displayed? In the past, this test was frequently
* done by determining whether the domain ended with a {@linkplain
* #isPublicSuffix() public suffix} but was not itself a public suffix. However,
* this test is no longer accurate. There are many domains which are both public
* suffixes and addressable as hosts; {@code "uk.com"} is one example. As a
* result, the only useful test to determine if a domain is a plausible web host
* is {@link #hasPublicSuffix()}. This will return {@code true} for many domains
* which (currently) are not hosts, such as {@code "com"}), but given that any
* public suffix may become a host without warning, it is better to err on the
* side of permissiveness and thus avoid spurious rejection of valid sites.
*
* <p>During construction, names are normalized in two ways:
* <ol>
* <li>ASCII uppercase characters are converted to lowercase.
* <li>Unicode dot separators other than the ASCII period ({@code '.'}) are
* converted to the ASCII period.
* </ol>
* The normalized values will be returned from {@link #name()} and
* {@link #parts()}, and will be reflected in the result of
* {@link #equals(Object)}.
*
* <p><a href="http://en.wikipedia.org/wiki/Internationalized_domain_name">
* internationalized domain names</a> such as {@code 网络.cn} are supported, as
* are the equivalent <a
* href="http://en.wikipedia.org/wiki/Internationalized_domain_name">IDNA
* Punycode-encoded</a> versions.
*
* @author Craig Berry
* @since 5.0
*/
@Beta
@GwtCompatible(emulated = true)
public final class InternetDomainName {
private static final CharMatcher DOTS_MATCHER =
CharMatcher.anyOf(".\u3002\uFF0E\uFF61");
private static final Splitter DOT_SPLITTER = Splitter.on('.');
private static final Joiner DOT_JOINER = Joiner.on('.');
/**
* Value of {@link #publicSuffixIndex} which indicates that no public suffix
* was found.
*/
private static final int NO_PUBLIC_SUFFIX_FOUND = -1;
private static final String DOT_REGEX = "\\.";
/**
* Maximum parts (labels) in a domain name. This value arises from
* the 255-octet limit described in
* <a href="http://www.ietf.org/rfc/rfc2181.txt">RFC 2181</a> part 11 with
* the fact that the encoding of each part occupies at least two bytes
* (dot plus label externally, length byte plus label internally). Thus, if
* all labels have the minimum size of one byte, 127 of them will fit.
*/
private static final int MAX_PARTS = 127;
/**
* Maximum length of a full domain name, including separators, and
* leaving room for the root label. See
* <a href="http://www.ietf.org/rfc/rfc2181.txt">RFC 2181</a> part 11.
*/
private static final int MAX_LENGTH = 253;
/**
* Maximum size of a single part of a domain name. See
* <a href="http://www.ietf.org/rfc/rfc2181.txt">RFC 2181</a> part 11.
*/
private static final int MAX_DOMAIN_PART_LENGTH = 63;
/**
* The full domain name, converted to lower case.
*/
private final String name;
/**
* The parts of the domain name, converted to lower case.
*/
private final ImmutableList<String> parts;
/**
* The index in the {@link #parts()} list at which the public suffix begins.
* For example, for the domain name {@code www.google.co.uk}, the value would
* be 2 (the index of the {@code co} part). The value is negative
* (specifically, {@link #NO_PUBLIC_SUFFIX_FOUND}) if no public suffix was
* found.
*/
private final int publicSuffixIndex;
/**
* Constructor used to implement {@link #from(String)}, and from subclasses.
*/
InternetDomainName(String name) {
// Normalize:
// * ASCII characters to lowercase
// * All dot-like characters to '.'
// * Strip trailing '.'
name = Ascii.toLowerCase(DOTS_MATCHER.replaceFrom(name, '.'));
if (name.endsWith(".")) {
name = name.substring(0, name.length() - 1);
}
checkArgument(name.length() <= MAX_LENGTH, "Domain name too long: '%s':", name);
this.name = name;
this.parts = ImmutableList.copyOf(DOT_SPLITTER.split(name));
checkArgument(parts.size() <= MAX_PARTS, "Domain has too many parts: '%s'", name);
checkArgument(validateSyntax(parts), "Not a valid domain name: '%s'", name);
this.publicSuffixIndex = findPublicSuffix();
}
/**
* Returns the index of the leftmost part of the public suffix, or -1 if not
* found. Note that the value defined as the "public suffix" may not be a
* public suffix according to {@link #isPublicSuffix()} if the domain ends
* with an excluded domain pattern such as {@code "nhs.uk"}.
*/
private int findPublicSuffix() {
final int partsSize = parts.size();
for (int i = 0; i < partsSize; i++) {
String ancestorName = DOT_JOINER.join(parts.subList(i, partsSize));
if (TldPatterns.EXACT.contains(ancestorName)) {
return i;
}
// Excluded domains (e.g. !nhs.uk) use the next highest
// domain as the effective public suffix (e.g. uk).
if (TldPatterns.EXCLUDED.contains(ancestorName)) {
return i + 1;
}
if (matchesWildcardPublicSuffix(ancestorName)) {
return i;
}
}
return NO_PUBLIC_SUFFIX_FOUND;
}
/**
* A deprecated synonym for {@link #from(String)}.
*
* @param domain A domain name (not IP address)
* @throws IllegalArgumentException if {@code name} is not syntactically valid
* according to {@link #isValidLenient}
* @since 8.0 (previously named {@code from})
* @deprecated Use {@link #from(String)}
*/
@Deprecated
public static InternetDomainName fromLenient(String domain) {
return from(domain);
}
/**
* Returns an instance of {@link InternetDomainName} after lenient
* validation. Specifically, validation against <a
* href="http://www.ietf.org/rfc/rfc3490.txt">RFC 3490</a>
* ("Internationalizing Domain Names in Applications") is skipped, while
* validation against <a
* href="http://www.ietf.org/rfc/rfc1035.txt">RFC 1035</a> is relaxed in
* the following ways:
* <ul>
* <li>Any part containing non-ASCII characters is considered valid.
* <li>Underscores ('_') are permitted wherever dashes ('-') are permitted.
* <li>Parts other than the final part may start with a digit.
* </ul>
*
*
* @param domain A domain name (not IP address)
* @throws IllegalArgumentException if {@code name} is not syntactically valid
* according to {@link #isValid}
* @since 10.0 (previously named {@code fromLenient})
*/
public static InternetDomainName from(String domain) {
return new InternetDomainName(checkNotNull(domain));
}
/**
* Validation method used by {@from} to ensure that the domain name is
* syntactically valid according to RFC 1035.
*
* @return Is the domain name syntactically valid?
*/
private static boolean validateSyntax(List<String> parts) {
final int lastIndex = parts.size() - 1;
// Validate the last part specially, as it has different syntax rules.
if (!validatePart(parts.get(lastIndex), true)) {
return false;
}
for (int i = 0; i < lastIndex; i++) {
String part = parts.get(i);
if (!validatePart(part, false)) {
return false;
}
}
return true;
}
private static final CharMatcher DASH_MATCHER = CharMatcher.anyOf("-_");
private static final CharMatcher PART_CHAR_MATCHER =
CharMatcher.JAVA_LETTER_OR_DIGIT.or(DASH_MATCHER);
/**
* Helper method for {@link #validateSyntax(List)}. Validates that one part of
* a domain name is valid.
*
* @param part The domain name part to be validated
* @param isFinalPart Is this the final (rightmost) domain part?
* @return Whether the part is valid
*/
private static boolean validatePart(String part, boolean isFinalPart) {
// These tests could be collapsed into one big boolean expression, but
// they have been left as independent tests for clarity.
if (part.length() < 1 || part.length() > MAX_DOMAIN_PART_LENGTH) {
return false;
}
/*
* GWT claims to support java.lang.Character's char-classification methods,
* but it actually only works for ASCII. So for now, assume any non-ASCII
* characters are valid. The only place this seems to be documented is here:
* http://osdir.com/ml/GoogleWebToolkitContributors/2010-03/msg00178.html
*
* <p>ASCII characters in the part are expected to be valid per RFC 1035,
* with underscore also being allowed due to widespread practice.
*/
String asciiChars = CharMatcher.ASCII.retainFrom(part);
if (!PART_CHAR_MATCHER.matchesAllOf(asciiChars)) {
return false;
}
// No initial or final dashes or underscores.
if (DASH_MATCHER.matches(part.charAt(0))
|| DASH_MATCHER.matches(part.charAt(part.length() - 1))) {
return false;
}
/*
* Note that we allow (in contravention of a strict interpretation of the
* relevant RFCs) domain parts other than the last may begin with a digit
* (for example, "3com.com"). It's important to disallow an initial digit in
* the last part; it's the only thing that stops an IPv4 numeric address
* like 127.0.0.1 from looking like a valid domain name.
*/
if (isFinalPart && CharMatcher.DIGIT.matches(part.charAt(0))) {
return false;
}
return true;
}
/**
* Returns the domain name, normalized to all lower case.
*/
public String name() {
return name;
}
/**
* Returns the individual components of this domain name, normalized to all
* lower case. For example, for the domain name {@code mail.google.com}, this
* method returns the list {@code ["mail", "google", "com"]}.
*/
public ImmutableList<String> parts() {
return parts;
}
/**
* Indicates whether this domain name represents a <i>public suffix</i>, as
* defined by the Mozilla Foundation's
* <a href="http://publicsuffix.org/">Public Suffix List</a> (PSL). A public
* suffix is one under which Internet users can directly register names, such
* as {@code com}, {@code co.uk} or {@code pvt.k12.wy.us}. Examples of domain
* names that are <i>not</i> public suffixes include {@code google}, {@code
* google.com} and {@code foo.co.uk}.
*
* @return {@code true} if this domain name appears exactly on the public
* suffix list
* @since 6.0
*/
public boolean isPublicSuffix() {
return publicSuffixIndex == 0;
}
/**
* Indicates whether this domain name ends in a {@linkplain #isPublicSuffix()
* public suffix}, including if it is a public suffix itself. For example,
* returns {@code true} for {@code www.google.com}, {@code foo.co.uk} and
* {@code com}, but not for {@code google} or {@code google.foo}. This is
* the recommended method for determining whether a domain is potentially an
* addressable host.
*
* @since 6.0
*/
public boolean hasPublicSuffix() {
return publicSuffixIndex != NO_PUBLIC_SUFFIX_FOUND;
}
/**
* Returns the {@linkplain #isPublicSuffix() public suffix} portion of the
* domain name, or {@code null} if no public suffix is present.
*
* @since 6.0
*/
public InternetDomainName publicSuffix() {
return hasPublicSuffix() ? ancestor(publicSuffixIndex) : null;
}
/**
* Indicates whether this domain name ends in a {@linkplain #isPublicSuffix()
* public suffix}, while not being a public suffix itself. For example,
* returns {@code true} for {@code www.google.com}, {@code foo.co.uk} and
* {@code bar.ca.us}, but not for {@code google}, {@code com}, or {@code
* google.foo}.
*
* <p><b>Warning:</b> a {@code false} result from this method does not imply
* that the domain does not represent an addressable host, as many public
* suffixes are also addressable hosts. Use {@link #hasPublicSuffix()} for
* that test.
*
* <p>This method can be used to determine whether it will probably be
* possible to set cookies on the domain, though even that depends on
* individual browsers' implementations of cookie controls. See
* <a href="http://www.ietf.org/rfc/rfc2109.txt">RFC 2109</a> for details.
*
* @since 6.0
*/
public boolean isUnderPublicSuffix() {
return publicSuffixIndex > 0;
}
/**
* Indicates whether this domain name is composed of exactly one subdomain
* component followed by a {@linkplain #isPublicSuffix() public suffix}. For
* example, returns {@code true} for {@code google.com} and {@code foo.co.uk},
* but not for {@code www.google.com} or {@code co.uk}.
*
* <p><b>Warning:</b> A {@code true} result from this method does not imply
* that the domain is at the highest level which is addressable as a host, as
* many public suffixes are also addressable hosts. For example, the domain
* {@code bar.uk.com} has a public suffix of {@code uk.com}, so it would
* return {@code true} from this method. But {@code uk.com} is itself an
* addressable host.
*
* <p>This method can be used to determine whether a domain is probably the
* highest level for which cookies may be set, though even that depends on
* individual browsers' implementations of cookie controls. See
* <a href="http://www.ietf.org/rfc/rfc2109.txt">RFC 2109</a> for details.
*
* @since 6.0
*/
public boolean isTopPrivateDomain() {
return publicSuffixIndex == 1;
}
/**
* Returns the portion of this domain name that is one level beneath the
* public suffix. For example, for {@code x.adwords.google.co.uk} it returns
* {@code google.co.uk}, since {@code co.uk} is a public suffix.
*
* <p>If {@link #isTopPrivateDomain()} is true, the current domain name
* instance is returned.
*
* <p>This method should not be used to determine the topmost parent domain
* which is addressable as a host, as many public suffixes are also
* addressable hosts. For example, the domain {@code foo.bar.uk.com} has
* a public suffix of {@code uk.com}, so it would return {@code bar.uk.com}
* from this method. But {@code uk.com} is itself an addressable host.
*
* <p>This method can be used to determine the probable highest level parent
* domain for which cookies may be set, though even that depends on individual
* browsers' implementations of cookie controls.
*
* @throws IllegalStateException if this domain does not end with a
* public suffix
* @since 6.0
*/
public InternetDomainName topPrivateDomain() {
if (isTopPrivateDomain()) {
return this;
}
checkState(isUnderPublicSuffix(), "Not under a public suffix: %s", name);
return ancestor(publicSuffixIndex - 1);
}
/**
* Indicates whether this domain is composed of two or more parts.
*/
public boolean hasParent() {
return parts.size() > 1;
}
/**
* Returns an {@code InternetDomainName} that is the immediate ancestor of
* this one; that is, the current domain with the leftmost part removed. For
* example, the parent of {@code www.google.com} is {@code google.com}.
*
* @throws IllegalStateException if the domain has no parent, as determined
* by {@link #hasParent}
*/
public InternetDomainName parent() {
checkState(hasParent(), "Domain '%s' has no parent", name);
return ancestor(1);
}
/**
* Returns the ancestor of the current domain at the given number of levels
* "higher" (rightward) in the subdomain list. The number of levels must be
* non-negative, and less than {@code N-1}, where {@code N} is the number of
* parts in the domain.
*
* <p>TODO: Reasonable candidate for addition to public API.
*/
private InternetDomainName ancestor(int levels) {
return from(DOT_JOINER.join(parts.subList(levels, parts.size())));
}
/**
* Creates and returns a new {@code InternetDomainName} by prepending the
* argument and a dot to the current name. For example, {@code
* InternetDomainName.from("foo.com").child("www.bar")} returns a new
* {@code InternetDomainName} with the value {@code www.bar.foo.com}. Only
* lenient validation is performed, as described {@link #from(String) here}.
*
* @throws NullPointerException if leftParts is null
* @throws IllegalArgumentException if the resulting name is not valid
*/
public InternetDomainName child(String leftParts) {
return from(checkNotNull(leftParts) + "." + name);
}
/**
* A deprecated synonym for {@link #isValid(String)}.
*
* @since 8.0 (previously named {@code isValid})
* @deprecated Use {@link #isValid(String)} instead
*/
@Deprecated
public static boolean isValidLenient(String name) {
return isValid(name);
}
/**
* Indicates whether the argument is a syntactically valid domain name using
* lenient validation. Specifically, validation against <a
* href="http://www.ietf.org/rfc/rfc3490.txt">RFC 3490</a>
* ("Internationalizing Domain Names in Applications") is skipped.
*
* <p>The following two code snippets are equivalent:
*
* <pre> {@code
*
* domainName = InternetDomainName.isValid(name)
* ? InternetDomainName.from(name)
* : DEFAULT_DOMAIN;
* }</pre>
*
* <pre> {@code
*
* try {
* domainName = InternetDomainName.from(name);
* } catch (IllegalArgumentException e) {
* domainName = DEFAULT_DOMAIN;
* }}</pre>
*
* @since 8.0 (previously named {@code isValidLenient})
*/
public static boolean isValid(String name) {
try {
from(name);
return true;
} catch (IllegalArgumentException e) {
return false;
}
}
/**
* Does the domain name match one of the "wildcard" patterns (e.g.
* {@code "*.ar"})?
*/
private static boolean matchesWildcardPublicSuffix(String domain) {
final String[] pieces = domain.split(DOT_REGEX, 2);
return pieces.length == 2 && TldPatterns.UNDER.contains(pieces[1]);
}
// TODO: specify this to return the same as name(); remove name()
@Override
public String toString() {
return Objects.toStringHelper(this).add("name", name).toString();
}
/**
* Equality testing is based on the text supplied by the caller,
* after normalization as described in the class documentation. For
* example, a non-ASCII Unicode domain name and the Punycode version
* of the same domain name would not be considered equal.
*
*/
@Override
public boolean equals(@Nullable Object object) {
if (object == this) {
return true;
}
if (object instanceof InternetDomainName) {
InternetDomainName that = (InternetDomainName) object;
return this.name.equals(that.name);
}
return false;
}
@Override
public int hashCode() {
return name.hashCode();
}
}
| 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.net;
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.base.Objects;
import java.util.regex.Matcher;
import java.util.regex.Pattern;
import javax.annotation.concurrent.Immutable;
/**
* An immutable representation of a host and port.
*
* <p>Example usage:
* <pre>
* HostAndPort hp = HostAndPort.fromString("[2001:db8::1]")
* .withDefaultPort(80)
* .requireBracketsForIPv6();
* hp.getHostText(); // returns "2001:db8::1"
* hp.getPort(); // returns 80
* hp.toString(); // returns "[2001:db8::1]:80"
* </pre>
*
* <p>Here are some examples of recognized formats:
* <ul>
* <li>example.com
* <li>example.com:80
* <li>192.0.2.1
* <li>192.0.2.1:80
* <li>[2001:db8::1] - {@link #getHostText()} omits brackets
* <li>[2001:db8::1]:80 - {@link #getHostText()} omits brackets
* <li>2001:db8::1 - Use {@link #requireBracketsForIPv6()} to prohibit this
* </ul>
*
* <p>Note that this is not an exhaustive list, because these methods are only
* concerned with brackets, colons, and port numbers. Full validation of the
* host field (if desired) is the caller's responsibility.
*
* @author Paul Marks
* @since 10.0
*/
@Beta @Immutable
public final class HostAndPort {
/** Magic value indicating the absence of a port number. */
private static final int NO_PORT = -1;
/** Hostname, IPv4/IPv6 literal, or unvalidated nonsense. */
private final String host;
/** Validated port number in the range [0..65535], or NO_PORT */
private final int port;
/** True if the parsed host has colons, but no surrounding brackets. */
private final boolean hasBracketlessColons;
private HostAndPort(String host, int port, boolean hasBracketlessColons) {
this.host = host;
this.port = port;
this.hasBracketlessColons = hasBracketlessColons;
}
/**
* Returns the portion of this {@code HostAndPort} instance that should
* represent the hostname or IPv4/IPv6 literal.
*
* A successful parse does not imply any degree of sanity in this field.
* For additional validation, see the {@link HostSpecifier} class.
*/
public String getHostText() {
return host;
}
/** Return true if this instance has a defined port. */
public boolean hasPort() {
return port >= 0;
}
/**
* Get the current port number, failing if no port is defined.
*
* @return a validated port number, in the range [0..65535]
* @throws IllegalStateException if no port is defined. You can use
* {@link #withDefaultPort(int)} to prevent this from occurring.
*/
public int getPort() {
checkState(hasPort());
return port;
}
/**
* Returns the current port number, with a default if no port is defined.
*/
public int getPortOrDefault(int defaultPort) {
return hasPort() ? port : defaultPort;
}
/**
* Build a HostAndPort instance from separate host and port values.
*
* <p>Note: Non-bracketed IPv6 literals are allowed.
* Use {@link #requireBracketsForIPv6()} to prohibit these.
*
* @param host the host string to parse. Must not contain a port number.
* @param port a port number from [0..65535]
* @return if parsing was successful, a populated HostAndPort object.
* @throws IllegalArgumentException if {@code host} contains a port number,
* or {@code port} is out of range.
*/
public static HostAndPort fromParts(String host, int port) {
checkArgument(isValidPort(port));
HostAndPort parsedHost = fromString(host);
checkArgument(!parsedHost.hasPort());
return new HostAndPort(parsedHost.host, port, parsedHost.hasBracketlessColons);
}
private static final Pattern BRACKET_PATTERN = Pattern.compile("^\\[(.*:.*)\\](?::(\\d*))?$");
/**
* Split a freeform string into a host and port, without strict validation.
*
* Note that the host-only formats will leave the port field undefined. You
* can use {@link #withDefaultPort(int)} to patch in a default value.
*
* @param hostPortString the input string to parse.
* @return if parsing was successful, a populated HostAndPort object.
* @throws IllegalArgumentException if nothing meaningful could be parsed.
*/
public static HostAndPort fromString(String hostPortString) {
checkNotNull(hostPortString);
String host;
String portString = null;
boolean hasBracketlessColons = false;
if (hostPortString.startsWith("[")) {
// Parse a bracketed host, typically an IPv6 literal.
Matcher matcher = BRACKET_PATTERN.matcher(hostPortString);
checkArgument(matcher.matches(), "Invalid bracketed host/port: %s", hostPortString);
host = matcher.group(1);
portString = matcher.group(2); // could be null
} else {
int colonPos = hostPortString.indexOf(':');
if (colonPos >= 0 && hostPortString.indexOf(':', colonPos + 1) == -1) {
// Exactly 1 colon. Split into host:port.
host = hostPortString.substring(0, colonPos);
portString = hostPortString.substring(colonPos + 1);
} else {
// 0 or 2+ colons. Bare hostname or IPv6 literal.
host = hostPortString;
hasBracketlessColons = (colonPos >= 0);
}
}
int port = NO_PORT;
if (portString != null) {
// Try to parse the whole port string as a number.
// JDK7 accepts leading plus signs. We don't want to.
checkArgument(!portString.startsWith("+"), "Unparseable port number: %s", hostPortString);
try {
port = Integer.parseInt(portString);
} catch (NumberFormatException e) {
throw new IllegalArgumentException("Unparseable port number: " + hostPortString);
}
checkArgument(isValidPort(port), "Port number out of range: %s", hostPortString);
}
return new HostAndPort(host, port, hasBracketlessColons);
}
/**
* Provide a default port if the parsed string contained only a host.
*
* You can chain this after {@link #fromString(String)} to include a port in
* case the port was omitted from the input string. If a port was already
* provided, then this method is a no-op.
*
* @param defaultPort a port number, from [0..65535]
* @return a HostAndPort instance, guaranteed to have a defined port.
*/
public HostAndPort withDefaultPort(int defaultPort) {
checkArgument(isValidPort(defaultPort));
if (hasPort() || port == defaultPort) {
return this;
}
return new HostAndPort(host, defaultPort, hasBracketlessColons);
}
/**
* Generate an error if the host might be a non-bracketed IPv6 literal.
*
* <p>URI formatting requires that IPv6 literals be surrounded by brackets,
* like "[2001:db8::1]". Chain this call after {@link #fromString(String)}
* to increase the strictness of the parser, and disallow IPv6 literals
* that don't contain these brackets.
*
* <p>Note that this parser identifies IPv6 literals solely based on the
* presence of a colon. To perform actual validation of IP addresses, see
* the {@link InetAddresses#forString(String)} method.
*
* @return {@code this}, to enable chaining of calls.
* @throws IllegalArgumentException if bracketless IPv6 is detected.
*/
public HostAndPort requireBracketsForIPv6() {
checkArgument(!hasBracketlessColons, "Possible bracketless IPv6 literal: %s", host);
return this;
}
@Override
public boolean equals(Object other) {
if (this == other) {
return true;
}
if (other instanceof HostAndPort) {
HostAndPort that = (HostAndPort) other;
return Objects.equal(this.host, that.host)
&& this.port == that.port
&& this.hasBracketlessColons == that.hasBracketlessColons;
}
return false;
}
@Override
public int hashCode() {
return Objects.hashCode(host, port, hasBracketlessColons);
}
/** Rebuild the host:port string, including brackets if necessary. */
@Override
public String toString() {
StringBuilder builder = new StringBuilder(host.length() + 7);
if (host.indexOf(':') >= 0) {
builder.append('[').append(host).append(']');
} else {
builder.append(host);
}
if (hasPort()) {
builder.append(':').append(port);
}
return builder.toString();
}
/** Return true for valid port numbers. */
private static boolean isValidPort(int port) {
return port >= 0 && port <= 65535;
}
}
| 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.GwtCompatible;
/**
* Implementation of {@link ImmutableListMultimap} with no entries.
*
* @author Jared Levy
*/
@GwtCompatible(serializable = true)
class EmptyImmutableListMultimap extends ImmutableListMultimap<Object, Object> {
static final EmptyImmutableListMultimap INSTANCE
= new EmptyImmutableListMultimap();
private EmptyImmutableListMultimap() {
super(ImmutableMap.<Object, ImmutableList<Object>>of(), 0);
}
private Object readResolve() {
return INSTANCE; // preserve singleton property
}
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.collect;
import com.google.common.annotations.GwtCompatible;
import java.util.concurrent.ConcurrentMap;
/**
* A concurrent map which forwards all its method calls to another concurrent
* map. Subclasses should override one or more methods to modify the behavior of
* the backing map as desired per the <a
* href="http://en.wikipedia.org/wiki/Decorator_pattern">decorator pattern</a>.
*
* @author Charles Fry
* @since 2.0 (imported from Google Collections Library)
*/
@GwtCompatible
public abstract class ForwardingConcurrentMap<K, V> extends ForwardingMap<K, V>
implements ConcurrentMap<K, V> {
/** Constructor for use by subclasses. */
protected ForwardingConcurrentMap() {}
@Override protected abstract ConcurrentMap<K, V> delegate();
@Override
public V putIfAbsent(K key, V value) {
return delegate().putIfAbsent(key, value);
}
@Override
public boolean remove(Object key, Object value) {
return delegate().remove(key, value);
}
@Override
public V replace(K key, V value) {
return delegate().replace(key, value);
}
@Override
public boolean replace(K key, V oldValue, V newValue) {
return delegate().replace(key, oldValue, newValue);
}
}
| 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.Map;
import javax.annotation.Nullable;
/**
* A map, each entry of which maps a Java
* <a href="http://tinyurl.com/2cmwkz">raw type</a> to an instance of that type.
* In addition to implementing {@code Map}, the additional type-safe operations
* {@link #putInstance} and {@link #getInstance} are available.
*
* <p>Like any other {@code Map<Class, Object>}, this map may contain entries
* for primitive types, and a primitive type and its corresponding wrapper type
* may map to different values.
*
* <p>See the Guava User Guide article on <a href=
* "http://code.google.com/p/guava-libraries/wiki/NewCollectionTypesExplained#ClassToInstanceMap">
* {@code ClassToInstanceMap}</a>.
*
* @param <B> the common supertype that all entries must share; often this is
* simply {@link Object}
*
* @author Kevin Bourrillion
* @since 2.0 (imported from Google Collections Library)
*/
@GwtCompatible
public interface ClassToInstanceMap<B> extends Map<Class<? extends B>, B> {
/**
* Returns the value the specified class is mapped to, or {@code null} if no
* entry for this class is present. This will only return a value that was
* bound to this specific class, not a value that may have been bound to a
* subtype.
*/
<T extends B> T getInstance(Class<T> type);
/**
* Maps the specified class to the specified value. Does <i>not</i> associate
* this value with any of the class's supertypes.
*
* @return the value previously associated with this class (possibly {@code
* null}), or {@code null} if there was no previous entry.
*/
<T extends B> T putInstance(Class<T> type, @Nullable T 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 com.google.common.annotations.GwtCompatible;
import java.io.Serializable;
import java.util.Collection;
import java.util.EnumSet;
/**
* Implementation of {@link ImmutableSet} backed by a non-empty {@link
* java.util.EnumSet}.
*
* @author Jared Levy
*/
@GwtCompatible(serializable = true, emulated = true)
@SuppressWarnings("serial") // we're overriding default serialization
final class ImmutableEnumSet<E extends Enum<E>> extends ImmutableSet<E> {
/*
* Notes on EnumSet and <E extends Enum<E>>:
*
* This class isn't an arbitrary ForwardingImmutableSet because we need to
* know that calling {@code clone()} during deserialization will return an
* object that no one else has a reference to, allowing us to guarantee
* immutability. Hence, we support only {@link EnumSet}.
*/
private final transient EnumSet<E> delegate;
ImmutableEnumSet(EnumSet<E> delegate) {
this.delegate = delegate;
}
@Override boolean isPartialView() {
return false;
}
@Override public UnmodifiableIterator<E> iterator() {
return Iterators.unmodifiableIterator(delegate.iterator());
}
@Override
public int size() {
return delegate.size();
}
@Override public boolean contains(Object object) {
return delegate.contains(object);
}
@Override public boolean containsAll(Collection<?> collection) {
return delegate.containsAll(collection);
}
@Override public boolean isEmpty() {
return delegate.isEmpty();
}
@Override public Object[] toArray() {
return delegate.toArray();
}
@Override public <T> T[] toArray(T[] array) {
return delegate.toArray(array);
}
@Override public boolean equals(Object object) {
return object == this || delegate.equals(object);
}
private transient int hashCode;
@Override public int hashCode() {
int result = hashCode;
return (result == 0) ? hashCode = delegate.hashCode() : result;
}
@Override public String toString() {
return delegate.toString();
}
// All callers of the constructor are restricted to <E extends Enum<E>>.
@Override Object writeReplace() {
return new EnumSerializedForm<E>(delegate);
}
/*
* This class is used to serialize ImmutableEnumSet instances.
*/
private static class EnumSerializedForm<E extends Enum<E>>
implements Serializable {
final EnumSet<E> delegate;
EnumSerializedForm(EnumSet<E> delegate) {
this.delegate = delegate;
}
Object readResolve() {
// EJ2 #76: Write readObject() methods defensively.
return new ImmutableEnumSet<E>(delegate.clone());
}
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.collect;
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 java.util.Collections;
import java.util.Comparator;
import java.util.List;
import java.util.RandomAccess;
import javax.annotation.Nullable;
/**
* Static methods pertaining to sorted {@link List} instances.
*
* In this documentation, the terms <i>greatest</i>, <i>greater</i>, <i>least</i>, and
* <i>lesser</i> are considered to refer to the comparator on the elements, and the terms
* <i>first</i> and <i>last</i> are considered to refer to the elements' ordering in a
* list.
*
* @author Louis Wasserman
*/
@GwtCompatible
@Beta final class SortedLists {
private SortedLists() {}
/**
* A specification for which index to return if the list contains at least one element that
* compares as equal to the key.
*/
public enum KeyPresentBehavior {
/**
* Return the index of any list element that compares as equal to the key. No guarantees are
* made as to which index is returned, if more than one element compares as equal to the key.
*/
ANY_PRESENT {
@Override
<E> int resultIndex(
Comparator<? super E> comparator, E key, List<? extends E> list, int foundIndex) {
return foundIndex;
}
},
/**
* Return the index of the last list element that compares as equal to the key.
*/
LAST_PRESENT {
@Override
<E> int resultIndex(
Comparator<? super E> comparator, E key, List<? extends E> list, int foundIndex) {
// Of course, we have to use binary search to find the precise
// breakpoint...
int lower = foundIndex;
int upper = list.size() - 1;
// Everything between lower and upper inclusive compares at >= 0.
while (lower < upper) {
int middle = (lower + upper + 1) >>> 1;
int c = comparator.compare(list.get(middle), key);
if (c > 0) {
upper = middle - 1;
} else { // c == 0
lower = middle;
}
}
return lower;
}
},
/**
* Return the index of the first list element that compares as equal to the key.
*/
FIRST_PRESENT {
@Override
<E> int resultIndex(
Comparator<? super E> comparator, E key, List<? extends E> list, int foundIndex) {
// Of course, we have to use binary search to find the precise
// breakpoint...
int lower = 0;
int upper = foundIndex;
// Of course, we have to use binary search to find the precise breakpoint...
// Everything between lower and upper inclusive compares at <= 0.
while (lower < upper) {
int middle = (lower + upper) >>> 1;
int c = comparator.compare(list.get(middle), key);
if (c < 0) {
lower = middle + 1;
} else { // c == 0
upper = middle;
}
}
return lower;
}
},
/**
* Return the index of the first list element that compares as greater than the key, or {@code
* list.size()} if there is no such element.
*/
FIRST_AFTER {
@Override
public <E> int resultIndex(
Comparator<? super E> comparator, E key, List<? extends E> list, int foundIndex) {
return LAST_PRESENT.resultIndex(comparator, key, list, foundIndex) + 1;
}
},
/**
* Return the index of the last list element that compares as less than the key, or {@code -1}
* if there is no such element.
*/
LAST_BEFORE {
@Override
public <E> int resultIndex(
Comparator<? super E> comparator, E key, List<? extends E> list, int foundIndex) {
return FIRST_PRESENT.resultIndex(comparator, key, list, foundIndex) - 1;
}
};
abstract <E> int resultIndex(
Comparator<? super E> comparator, E key, List<? extends E> list, int foundIndex);
}
/**
* A specification for which index to return if the list contains no elements that compare as
* equal to the key.
*/
public enum KeyAbsentBehavior {
/**
* Return the index of the next lower element in the list, or {@code -1} if there is no such
* element.
*/
NEXT_LOWER {
@Override
<E> int resultIndex(int higherIndex) {
return higherIndex - 1;
}
},
/**
* Return the index of the next higher element in the list, or {@code list.size()} if there is
* no such element.
*/
NEXT_HIGHER {
@Override
public <E> int resultIndex(int higherIndex) {
return higherIndex;
}
},
/**
* Return {@code ~insertionIndex}, where {@code insertionIndex} is defined as the point at
* which the key would be inserted into the list: the index of the next higher element in the
* list, or {@code list.size()} if there is no such element.
*
* <p>Note that the return value will be {@code >= 0} if and only if there is an element of the
* list that compares as equal to the key.
*
* <p>This is equivalent to the behavior of
* {@link java.util.Collections#binarySearch(List, Object)} when the key isn't present, since
* {@code ~insertionIndex} is equal to {@code -1 - insertionIndex}.
*/
INVERTED_INSERTION_INDEX {
@Override
public <E> int resultIndex(int higherIndex) {
return ~higherIndex;
}
};
abstract <E> int resultIndex(int higherIndex);
}
/**
* Searches the specified naturally ordered list for the specified object using the binary search
* algorithm.
*
* <p>Equivalent to {@link #binarySearch(List, Function, Object, Comparator, KeyPresentBehavior,
* KeyAbsentBehavior)} using {@link Ordering#natural}.
*/
public static <E extends Comparable> int binarySearch(List<? extends E> list, E e,
KeyPresentBehavior presentBehavior, KeyAbsentBehavior absentBehavior) {
checkNotNull(e);
return binarySearch(
list, checkNotNull(e), Ordering.natural(), presentBehavior, absentBehavior);
}
/**
* Binary searches the list for the specified key, using the specified key function.
*
* <p>Equivalent to {@link #binarySearch(List, Function, Object, Comparator, KeyPresentBehavior,
* KeyAbsentBehavior)} using {@link Ordering#natural}.
*/
public static <E, K extends Comparable> int binarySearch(List<E> list,
Function<? super E, K> keyFunction, K key, KeyPresentBehavior presentBehavior,
KeyAbsentBehavior absentBehavior) {
return binarySearch(
list,
keyFunction,
key,
Ordering.natural(),
presentBehavior,
absentBehavior);
}
/**
* Binary searches the list for the specified key, using the specified key function.
*
* <p>Equivalent to
* {@link #binarySearch(List, Object, Comparator, KeyPresentBehavior, KeyAbsentBehavior)} using
* {@link Lists#transform(List, Function) Lists.transform(list, keyFunction)}.
*/
public static <E, K> int binarySearch(
List<E> list,
Function<? super E, K> keyFunction,
K key,
Comparator<? super K> keyComparator,
KeyPresentBehavior presentBehavior,
KeyAbsentBehavior absentBehavior) {
return binarySearch(
Lists.transform(list, keyFunction), key, keyComparator, presentBehavior, absentBehavior);
}
/**
* Searches the specified list for the specified object using the binary search algorithm. The
* list must be sorted into ascending order according to the specified comparator (as by the
* {@link Collections#sort(List, Comparator) Collections.sort(List, Comparator)} method), prior
* to making this call. If it is not sorted, the results are undefined.
*
* <p>If there are elements in the list which compare as equal to the key, the choice of
* {@link KeyPresentBehavior} decides which index is returned. If no elements compare as equal to
* the key, the choice of {@link KeyAbsentBehavior} decides which index is returned.
*
* <p>This method runs in log(n) time on random-access lists, which offer near-constant-time
* access to each list element.
*
* @param list the list to be searched.
* @param key the value to be searched for.
* @param comparator the comparator by which the list is ordered.
* @param presentBehavior the specification for what to do if at least one element of the list
* compares as equal to the key.
* @param absentBehavior the specification for what to do if no elements of the list compare as
* equal to the key.
* @return the index determined by the {@code KeyPresentBehavior}, if the key is in the list;
* otherwise the index determined by the {@code KeyAbsentBehavior}.
*/
public static <E> int binarySearch(List<? extends E> list, @Nullable E key,
Comparator<? super E> comparator, KeyPresentBehavior presentBehavior,
KeyAbsentBehavior absentBehavior) {
checkNotNull(comparator);
checkNotNull(list);
checkNotNull(presentBehavior);
checkNotNull(absentBehavior);
if (!(list instanceof RandomAccess)) {
list = Lists.newArrayList(list);
}
// TODO(user): benchmark when it's best to do a linear search
int lower = 0;
int upper = list.size() - 1;
while (lower <= upper) {
int middle = (lower + upper) >>> 1;
int c = comparator.compare(key, list.get(middle));
if (c < 0) {
upper = middle - 1;
} else if (c > 0) {
lower = middle + 1;
} else {
return lower + presentBehavior.resultIndex(
comparator, key, list.subList(lower, upper + 1), middle - lower);
}
}
return absentBehavior.resultIndex(lower);
}
}
| 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 static com.google.common.base.Preconditions.checkNotNull;
import com.google.common.annotations.GwtCompatible;
/**
* A rule for a local mutation to a binary search tree, that changes at most one entry. In addition
* to specifying how it modifies a particular entry via a {@code BstModifier}, it specifies a
* {@link BstBalancePolicy} for rebalancing the tree after the modification is performed and a
* {@link BstNodeFactory} for constructing newly rebalanced nodes.
*
* @author Louis Wasserman
* @param <K> The key type of the nodes in binary search trees that this rule can modify.
* @param <N> The type of the nodes in binary search trees that this rule can modify.
*/
@GwtCompatible
final class BstMutationRule<K, N extends BstNode<K, N>> {
/**
* Constructs a {@code BstMutationRule} with the specified modifier, balance policy, and node
* factory.
*/
public static <K, N extends BstNode<K, N>> BstMutationRule<K, N> createRule(
BstModifier<K, N> modifier, BstBalancePolicy<N> balancePolicy,
BstNodeFactory<N> nodeFactory) {
return new BstMutationRule<K, N>(modifier, balancePolicy, nodeFactory);
}
private final BstModifier<K, N> modifier;
private final BstBalancePolicy<N> balancePolicy;
private final BstNodeFactory<N> nodeFactory;
private BstMutationRule(BstModifier<K, N> modifier, BstBalancePolicy<N> balancePolicy,
BstNodeFactory<N> nodeFactory) {
this.balancePolicy = checkNotNull(balancePolicy);
this.nodeFactory = checkNotNull(nodeFactory);
this.modifier = checkNotNull(modifier);
}
/**
* Returns the {@link BstModifier} that specifies the change to a targeted entry in a binary
* search tree.
*/
public BstModifier<K, N> getModifier() {
return modifier;
}
/**
* Returns the policy used to rebalance nodes in the tree after this modification has been
* performed.
*/
public BstBalancePolicy<N> getBalancePolicy() {
return balancePolicy;
}
/**
* Returns the node factory used to create new nodes in the tree after this modification has been
* performed.
*/
public BstNodeFactory<N> getNodeFactory() {
return nodeFactory;
}
}
| 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 static com.google.common.base.Preconditions.checkNotNull;
import com.google.common.annotations.GwtCompatible;
import javax.annotation.Nullable;
/**
* The result of a {@code BstModifier}.
*
* @author Louis Wasserman
*/
@GwtCompatible
final class BstModificationResult<N extends BstNode<?, N>> {
enum ModificationType {
IDENTITY, REBUILDING_CHANGE, REBALANCING_CHANGE;
}
static <N extends BstNode<?, N>> BstModificationResult<N> identity(@Nullable N target) {
return new BstModificationResult<N>(target, target, ModificationType.IDENTITY);
}
static <N extends BstNode<?, N>> BstModificationResult<N> rebuildingChange(
@Nullable N originalTarget, @Nullable N changedTarget) {
return new BstModificationResult<N>(
originalTarget, changedTarget, ModificationType.REBUILDING_CHANGE);
}
static <N extends BstNode<?, N>> BstModificationResult<N> rebalancingChange(
@Nullable N originalTarget, @Nullable N changedTarget) {
return new BstModificationResult<N>(
originalTarget, changedTarget, ModificationType.REBALANCING_CHANGE);
}
@Nullable private final N originalTarget;
@Nullable private final N changedTarget;
private final ModificationType type;
private BstModificationResult(
@Nullable N originalTarget, @Nullable N changedTarget, ModificationType type) {
this.originalTarget = originalTarget;
this.changedTarget = changedTarget;
this.type = checkNotNull(type);
}
@Nullable
N getOriginalTarget() {
return originalTarget;
}
@Nullable
N getChangedTarget() {
return changedTarget;
}
ModificationType getType() {
return type;
}
}
| 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 java.util.List;
import java.util.Map;
import javax.annotation.Nullable;
/**
* Basic implementation of the {@link ListMultimap} interface. It's a wrapper
* around {@link AbstractMultimap} that converts the returned collections into
* {@code Lists}. The {@link #createCollection} method must return a {@code
* List}.
*
* @author Jared Levy
* @since 2.0 (imported from Google Collections Library)
*/
@GwtCompatible
abstract class AbstractListMultimap<K, V>
extends AbstractMultimap<K, V> implements ListMultimap<K, V> {
/**
* Creates a new multimap that uses the provided map.
*
* @param map place to store the mapping from each key to its corresponding
* values
*/
protected AbstractListMultimap(Map<K, Collection<V>> map) {
super(map);
}
@Override abstract List<V> createCollection();
// Following Javadoc copied from ListMultimap.
/**
* {@inheritDoc}
*
* <p>Because the values for a given key may have duplicates and follow the
* insertion ordering, this method returns a {@link List}, instead of the
* {@link Collection} specified in the {@link Multimap} interface.
*/
@Override public List<V> get(@Nullable K key) {
return (List<V>) super.get(key);
}
/**
* {@inheritDoc}
*
* <p>Because the values for a given key may have duplicates and follow the
* insertion ordering, this method returns a {@link List}, instead of the
* {@link Collection} specified in the {@link Multimap} interface.
*/
@Override public List<V> removeAll(@Nullable Object key) {
return (List<V>) super.removeAll(key);
}
/**
* {@inheritDoc}
*
* <p>Because the values for a given key may have duplicates and follow the
* insertion ordering, this method returns a {@link List}, instead of the
* {@link Collection} specified in the {@link Multimap} interface.
*/
@Override public List<V> replaceValues(
@Nullable K key, Iterable<? extends V> values) {
return (List<V>) super.replaceValues(key, values);
}
/**
* 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) {
return super.put(key, value);
}
/**
* {@inheritDoc}
*
* <p>Though the method signature doesn't say so explicitly, the returned map
* has {@link List} values.
*/
@Override public Map<K, Collection<V>> asMap() {
return super.asMap();
}
/**
* 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 object) {
return super.equals(object);
}
private static final long serialVersionUID = 6588350623831699109L;
}
| 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 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.Comparator;
import java.util.List;
import java.util.Map;
import javax.annotation.Nullable;
/**
* An immutable {@link Table} with reliable user-specified iteration order.
* Does not permit null keys or values.
*
* <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 gak@google.com (Gregory Kick)
* @since 11.0
*/
@Beta
@GwtCompatible
// TODO(gak): make serializable
public abstract class ImmutableTable<R, C, V> implements Table<R, C, V> {
/** Returns an empty immutable table. */
@SuppressWarnings("unchecked")
public static final <R, C, V> ImmutableTable<R, C, V> of() {
return (ImmutableTable<R, C, V>) EmptyImmutableTable.INSTANCE;
}
/** Returns an immutable table containing a single cell. */
public static final <R, C, V> ImmutableTable<R, C, V> of(R rowKey,
C columnKey, V value) {
return new SingletonImmutableTable<R, C, V>(rowKey, columnKey, value);
}
/**
* Returns an immutable copy of the provided table.
*
* <p>The {@link Table#cellSet()} iteration order of the provided table
* determines the iteration ordering of all views in the returned table. Note
* that some views of the original table and the copied table may have
* different iteration orders. For more control over the ordering, create a
* {@link Builder} and call {@link Builder#orderRowsBy},
* {@link Builder#orderColumnsBy}, and {@link Builder#putAll}
*
* <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.
*/
public static final <R, C, V> ImmutableTable<R, C, V> copyOf(
Table<? extends R, ? extends C, ? extends V> table) {
if (table instanceof ImmutableTable<?, ?, ?>) {
@SuppressWarnings("unchecked")
ImmutableTable<R, C, V> parameterizedTable
= (ImmutableTable<R, C, V>) table;
return parameterizedTable;
} else {
int size = table.size();
switch (size) {
case 0:
return of();
case 1:
Cell<? extends R, ? extends C, ? extends V> onlyCell
= Iterables.getOnlyElement(table.cellSet());
return ImmutableTable.<R, C, V>of(onlyCell.getRowKey(),
onlyCell.getColumnKey(), onlyCell.getValue());
default:
ImmutableSet.Builder<Cell<R, C, V>> cellSetBuilder
= ImmutableSet.builder();
for (Cell<? extends R, ? extends C, ? extends V> cell :
table.cellSet()) {
/*
* Must cast to be able to create a Cell<R, C, V> rather than a
* Cell<? extends R, ? extends C, ? extends V>
*/
cellSetBuilder.add(cellOf((R) cell.getRowKey(),
(C) cell.getColumnKey(), (V) cell.getValue()));
}
return RegularImmutableTable.forCells(cellSetBuilder.build());
}
}
}
/**
* Returns a new builder. The generated builder is equivalent to the builder
* created by the {@link Builder#Builder()} constructor.
*/
public static final <R, C, V> Builder<R, C, V> builder() {
return new Builder<R, C, V>();
}
/**
* Verifies that {@code rowKey}, {@code columnKey} and {@code value} are
* non-null, and returns a new entry with those values.
*/
static <R, C, V> Cell<R, C, V> cellOf(R rowKey, C columnKey, V value) {
return Tables.immutableCell(checkNotNull(rowKey), checkNotNull(columnKey),
checkNotNull(value));
}
/**
* A builder for creating immutable table instances, especially {@code public
* static final} tables ("constant tables"). Example: <pre> {@code
*
* static final ImmutableTable<Integer, Character, String> SPREADSHEET =
* new ImmutableTable.Builder<Integer, Character, String>()
* .put(1, 'A', "foo")
* .put(1, 'B', "bar")
* .put(2, 'A', "baz")
* .build();}</pre>
*
* <p>By default, the order in which cells are added to the builder determines
* the iteration ordering of all views in the returned table, with {@link
* #putAll} following the {@link Table#cellSet()} iteration order. However, if
* {@link #orderRowsBy} or {@link #orderColumnsBy} is called, the views are
* sorted by the supplied comparators.
*
* For empty or single-cell immutable tables, {@link #of()} and
* {@link #of(Object, Object, Object)} are even more convenient.
*
* <p>Builder instances can be reused - it is safe to call {@link #build}
* multiple times to build multiple tables in series. Each table is a superset
* of the tables created before it.
*
* @since 11.0
*/
public static final class Builder<R, C, V> {
private final List<Cell<R, C, V>> cells = Lists.newArrayList();
private Comparator<? super R> rowComparator;
private Comparator<? super C> columnComparator;
/**
* Creates a new builder. The returned builder is equivalent to the builder
* generated by {@link ImmutableTable#builder}.
*/
public Builder() {}
/**
* Specifies the ordering of the generated table's rows.
*/
public Builder<R, C, V> orderRowsBy(Comparator<? super R> rowComparator) {
this.rowComparator = checkNotNull(rowComparator);
return this;
}
/**
* Specifies the ordering of the generated table's columns.
*/
public Builder<R, C, V> orderColumnsBy(
Comparator<? super C> columnComparator) {
this.columnComparator = checkNotNull(columnComparator);
return this;
}
/**
* Associates the ({@code rowKey}, {@code columnKey}) pair with {@code
* value} in the built table. Duplicate key pairs are not allowed and will
* cause {@link #build} to fail.
*/
public Builder<R, C, V> put(R rowKey, C columnKey, V value) {
cells.add(cellOf(rowKey, columnKey, value));
return this;
}
/**
* Adds the given {@code cell} to the table, making it immutable if
* necessary. Duplicate key pairs are not allowed and will cause {@link
* #build} to fail.
*/
public Builder<R, C, V> put(
Cell<? extends R, ? extends C, ? extends V> cell) {
if (cell instanceof Tables.ImmutableCell) {
checkNotNull(cell.getRowKey());
checkNotNull(cell.getColumnKey());
checkNotNull(cell.getValue());
@SuppressWarnings("unchecked") // all supported methods are covariant
Cell<R, C, V> immutableCell = (Cell<R, C, V>) cell;
cells.add(immutableCell);
} else {
put(cell.getRowKey(), cell.getColumnKey(), cell.getValue());
}
return this;
}
/**
* Associates all of the given table's keys and values in the built table.
* Duplicate row key column key pairs are not allowed, and will cause
* {@link #build} to fail.
*
* @throws NullPointerException if any key or value in {@code table} is null
*/
public Builder<R, C, V> putAll(
Table<? extends R, ? extends C, ? extends V> table) {
for (Cell<? extends R, ? extends C, ? extends V> cell : table.cellSet()) {
put(cell);
}
return this;
}
/**
* Returns a newly-created immutable table.
*
* @throws IllegalArgumentException if duplicate key pairs were added
*/
public ImmutableTable<R, C, V> build() {
int size = cells.size();
switch (size) {
case 0:
return of();
case 1:
return new SingletonImmutableTable<R, C, V>(
Iterables.getOnlyElement(cells));
default:
return RegularImmutableTable.forCells(
cells, rowComparator, columnComparator);
}
}
}
ImmutableTable() {}
@Override public abstract ImmutableSet<Cell<R, C, V>> cellSet();
/**
* {@inheritDoc}
*
* @throws NullPointerException if {@code columnKey} is {@code null}
*/
@Override public abstract ImmutableMap<R, V> column(C columnKey);
@Override public abstract ImmutableSet<C> columnKeySet();
/**
* {@inheritDoc}
*
* <p>The value {@code Map<R, V>}s in the returned map are
* {@link ImmutableMap}s as well.
*/
@Override public abstract ImmutableMap<C, Map<R, V>> columnMap();
/**
* {@inheritDoc}
*
* @throws NullPointerException if {@code rowKey} is {@code null}
*/
@Override public abstract ImmutableMap<C, V> row(R rowKey);
@Override public abstract ImmutableSet<R> rowKeySet();
/**
* {@inheritDoc}
*
* <p>The value {@code Map<C, V>}s in the returned map are
* {@link ImmutableMap}s as well.
*/
@Override public abstract ImmutableMap<R, Map<C, V>> rowMap();
/**
* Guaranteed to throw an exception and leave the table unmodified.
*
* @throws UnsupportedOperationException always
*/
@Override public final void clear() {
throw new UnsupportedOperationException();
}
/**
* Guaranteed to throw an exception and leave the table unmodified.
*
* @throws UnsupportedOperationException always
*/
@Override public final V put(R rowKey, C columnKey, V value) {
throw new UnsupportedOperationException();
}
/**
* Guaranteed to throw an exception and leave the table unmodified.
*
* @throws UnsupportedOperationException always
*/
@Override public final void putAll(
Table<? extends R, ? extends C, ? extends V> table) {
throw new UnsupportedOperationException();
}
/**
* Guaranteed to throw an exception and leave the table unmodified.
*
* @throws UnsupportedOperationException always
*/
@Override public final V remove(Object rowKey, Object columnKey) {
throw new UnsupportedOperationException();
}
@Override public boolean equals(@Nullable Object obj) {
if (obj == this) {
return true;
} else if (obj instanceof Table<?, ?, ?>) {
Table<?, ?, ?> that = (Table<?, ?, ?>) obj;
return this.cellSet().equals(that.cellSet());
} else {
return false;
}
}
@Override public int hashCode() {
return cellSet().hashCode();
}
@Override public String toString() {
return rowMap().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.collect;
import static com.google.common.base.Preconditions.checkNotNull;
import com.google.common.annotations.GwtCompatible;
import com.google.common.base.Function;
import com.google.common.base.Objects;
import java.io.Serializable;
import javax.annotation.Nullable;
/**
* An ordering that orders elements by applying an order to the result of a
* function on those elements.
*/
@GwtCompatible(serializable = true)
final class ByFunctionOrdering<F, T>
extends Ordering<F> implements Serializable {
final Function<F, ? extends T> function;
final Ordering<T> ordering;
ByFunctionOrdering(
Function<F, ? extends T> function, Ordering<T> ordering) {
this.function = checkNotNull(function);
this.ordering = checkNotNull(ordering);
}
@Override public int compare(F left, F right) {
return ordering.compare(function.apply(left), function.apply(right));
}
@Override public boolean equals(@Nullable Object object) {
if (object == this) {
return true;
}
if (object instanceof ByFunctionOrdering) {
ByFunctionOrdering<?, ?> that = (ByFunctionOrdering<?, ?>) object;
return this.function.equals(that.function)
&& this.ordering.equals(that.ordering);
}
return false;
}
@Override public int hashCode() {
return Objects.hashCode(function, ordering);
}
@Override public String toString() {
return ordering + ".onResultOf(" + function + ")";
}
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.collect;
import com.google.common.annotations.GwtCompatible;
import java.util.Collection;
import java.util.Set;
import javax.annotation.Nullable;
/**
* An empty immutable set.
*
* @author Kevin Bourrillion
*/
@GwtCompatible(serializable = true, emulated = true)
final class EmptyImmutableSet extends ImmutableSet<Object> {
static final EmptyImmutableSet INSTANCE = new EmptyImmutableSet();
private EmptyImmutableSet() {}
@Override
public int size() {
return 0;
}
@Override public boolean isEmpty() {
return true;
}
@Override public boolean contains(Object target) {
return false;
}
@Override public UnmodifiableIterator<Object> iterator() {
return Iterators.emptyIterator();
}
@Override boolean isPartialView() {
return false;
}
private static final Object[] EMPTY_ARRAY = new Object[0];
@Override public Object[] toArray() {
return EMPTY_ARRAY;
}
@Override public <T> T[] toArray(T[] a) {
if (a.length > 0) {
a[0] = null;
}
return a;
}
@Override public boolean containsAll(Collection<?> targets) {
return targets.isEmpty();
}
@Override public boolean equals(@Nullable Object object) {
if (object instanceof Set) {
Set<?> that = (Set<?>) object;
return that.isEmpty();
}
return false;
}
@Override public final int hashCode() {
return 0;
}
@Override boolean isHashCodeFast() {
return true;
}
@Override public String toString() {
return "[]";
}
Object readResolve() {
return INSTANCE; // preserve singleton property
}
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.checkNotNull;
import static com.google.common.base.Preconditions.checkState;
import com.google.common.annotations.VisibleForTesting;
import com.google.common.base.Equivalence;
import com.google.common.base.Equivalences;
import com.google.common.base.Ticker;
import com.google.common.collect.GenericMapMaker.NullListener;
import com.google.common.collect.MapMaker.RemovalCause;
import com.google.common.collect.MapMaker.RemovalListener;
import com.google.common.collect.MapMaker.RemovalNotification;
import com.google.common.primitives.Ints;
import java.io.IOException;
import java.io.ObjectInputStream;
import java.io.ObjectOutputStream;
import java.io.Serializable;
import java.lang.ref.Reference;
import java.lang.ref.ReferenceQueue;
import java.lang.ref.SoftReference;
import java.lang.ref.WeakReference;
import java.util.AbstractCollection;
import java.util.AbstractMap;
import java.util.AbstractQueue;
import java.util.AbstractSet;
import java.util.Collection;
import java.util.Iterator;
import java.util.Map;
import java.util.NoSuchElementException;
import java.util.Queue;
import java.util.Set;
import java.util.concurrent.CancellationException;
import java.util.concurrent.ConcurrentLinkedQueue;
import java.util.concurrent.ConcurrentMap;
import java.util.concurrent.ExecutionException;
import java.util.concurrent.TimeUnit;
import java.util.concurrent.atomic.AtomicInteger;
import java.util.concurrent.atomic.AtomicReferenceArray;
import java.util.concurrent.locks.ReentrantLock;
import java.util.logging.Level;
import java.util.logging.Logger;
import javax.annotation.Nullable;
import javax.annotation.concurrent.GuardedBy;
/**
* The concurrent hash map implementation built by {@link MapMaker}.
*
* <p>This implementation is heavily derived from revision 1.96 of <a
* href="http://tinyurl.com/ConcurrentHashMap">ConcurrentHashMap.java</a>.
*
* @author Bob Lee
* @author Charles Fry
* @author Doug Lea ({@code ConcurrentHashMap})
*/
class MapMakerInternalMap<K, V>
extends AbstractMap<K, V> implements ConcurrentMap<K, V>, Serializable {
/*
* The basic strategy is to subdivide the table among Segments, each of which itself is a
* concurrently readable hash table. The map supports non-blocking reads and concurrent writes
* across different segments.
*
* If a maximum size is specified, a best-effort bounding is performed per segment, using a
* page-replacement algorithm to determine which entries to evict when the capacity has been
* exceeded.
*
* The page replacement algorithm's data structures are kept casually consistent with the map. The
* ordering of writes to a segment is sequentially consistent. An update to the map and recording
* of reads may not be immediately reflected on the algorithm's data structures. These structures
* are guarded by a lock and operations are applied in batches to avoid lock contention. The
* penalty of applying the batches is spread across threads so that the amortized cost is slightly
* higher than performing just the operation without enforcing the capacity constraint.
*
* This implementation uses a per-segment queue to record a memento of the additions, removals,
* and accesses that were performed on the map. The queue is drained on writes and when it exceeds
* its capacity threshold.
*
* The Least Recently Used page replacement algorithm was chosen due to its simplicity, high hit
* rate, and ability to be implemented with O(1) time complexity. The initial LRU implementation
* operates per-segment rather than globally for increased implementation simplicity. We expect
* the cache hit rate to be similar to that of a global LRU algorithm.
*/
// Constants
/**
* The maximum capacity, used if a higher value is implicitly specified by either of the
* constructors with arguments. MUST be a power of two <= 1<<30 to ensure that entries are
* indexable using ints.
*/
static final int MAXIMUM_CAPACITY = Ints.MAX_POWER_OF_TWO;
/** The maximum number of segments to allow; used to bound constructor arguments. */
static final int MAX_SEGMENTS = 1 << 16; // slightly conservative
/** Number of (unsynchronized) retries in the containsValue method. */
static final int CONTAINS_VALUE_RETRIES = 3;
/**
* Number of cache access operations that can be buffered per segment before the cache's recency
* ordering information is updated. This is used to avoid lock contention by recording a memento
* of reads and delaying a lock acquisition until the threshold is crossed or a mutation occurs.
*
* <p>This must be a (2^n)-1 as it is used as a mask.
*/
static final int DRAIN_THRESHOLD = 0x3F;
/**
* Maximum number of entries to be drained in a single cleanup run. This applies independently to
* the cleanup queue and both reference queues.
*/
// TODO(fry): empirically optimize this
static final int DRAIN_MAX = 16;
static final long CLEANUP_EXECUTOR_DELAY_SECS = 60;
// Fields
private static final Logger logger = Logger.getLogger(MapMakerInternalMap.class.getName());
/**
* Mask value for indexing into segments. The upper bits of a key's hash code are used to choose
* the segment.
*/
final transient int segmentMask;
/**
* Shift value for indexing within segments. Helps prevent entries that end up in the same segment
* from also ending up in the same bucket.
*/
final transient int segmentShift;
/** The segments, each of which is a specialized hash table. */
final transient Segment<K, V>[] segments;
/** The concurrency level. */
final int concurrencyLevel;
/** Strategy for comparing keys. */
final Equivalence<Object> keyEquivalence;
/** Strategy for comparing values. */
final Equivalence<Object> valueEquivalence;
/** Strategy for referencing keys. */
final Strength keyStrength;
/** Strategy for referencing values. */
final Strength valueStrength;
/** The maximum size of this map. MapMaker.UNSET_INT if there is no maximum. */
final int maximumSize;
/** How long after the last access to an entry the map will retain that entry. */
final long expireAfterAccessNanos;
/** How long after the last write to an entry the map will retain that entry. */
final long expireAfterWriteNanos;
/** Entries waiting to be consumed by the removal listener. */
// TODO(fry): define a new type which creates event objects and automates the clear logic
final Queue<RemovalNotification<K, V>> removalNotificationQueue;
/**
* A listener that is invoked when an entry is removed due to expiration or garbage collection of
* soft/weak entries.
*/
final RemovalListener<K, V> removalListener;
/** Factory used to create new entries. */
final transient EntryFactory entryFactory;
/** Measures time in a testable way. */
final Ticker ticker;
/**
* Creates a new, empty map with the specified strategy, initial capacity and concurrency level.
*/
MapMakerInternalMap(MapMaker builder) {
concurrencyLevel = Math.min(builder.getConcurrencyLevel(), MAX_SEGMENTS);
keyStrength = builder.getKeyStrength();
valueStrength = builder.getValueStrength();
keyEquivalence = builder.getKeyEquivalence();
valueEquivalence = builder.getValueEquivalence();
maximumSize = builder.maximumSize;
expireAfterAccessNanos = builder.getExpireAfterAccessNanos();
expireAfterWriteNanos = builder.getExpireAfterWriteNanos();
entryFactory = EntryFactory.getFactory(keyStrength, expires(), evictsBySize());
ticker = builder.getTicker();
removalListener = builder.getRemovalListener();
removalNotificationQueue = (removalListener == NullListener.INSTANCE)
? MapMakerInternalMap.<RemovalNotification<K, V>>discardingQueue()
: new ConcurrentLinkedQueue<RemovalNotification<K, V>>();
int initialCapacity = Math.min(builder.getInitialCapacity(), MAXIMUM_CAPACITY);
if (evictsBySize()) {
initialCapacity = Math.min(initialCapacity, maximumSize);
}
// Find power-of-two sizes best matching arguments. Constraints:
// (segmentCount <= maximumSize)
// && (concurrencyLevel > maximumSize || segmentCount > concurrencyLevel)
int segmentShift = 0;
int segmentCount = 1;
while (segmentCount < concurrencyLevel
&& (!evictsBySize() || segmentCount * 2 <= maximumSize)) {
++segmentShift;
segmentCount <<= 1;
}
this.segmentShift = 32 - segmentShift;
segmentMask = segmentCount - 1;
this.segments = newSegmentArray(segmentCount);
int segmentCapacity = initialCapacity / segmentCount;
if (segmentCapacity * segmentCount < initialCapacity) {
++segmentCapacity;
}
int segmentSize = 1;
while (segmentSize < segmentCapacity) {
segmentSize <<= 1;
}
if (evictsBySize()) {
// Ensure sum of segment max sizes = overall max size
int maximumSegmentSize = maximumSize / segmentCount + 1;
int remainder = maximumSize % segmentCount;
for (int i = 0; i < this.segments.length; ++i) {
if (i == remainder) {
maximumSegmentSize--;
}
this.segments[i] =
createSegment(segmentSize, maximumSegmentSize);
}
} else {
for (int i = 0; i < this.segments.length; ++i) {
this.segments[i] =
createSegment(segmentSize, MapMaker.UNSET_INT);
}
}
}
boolean evictsBySize() {
return maximumSize != MapMaker.UNSET_INT;
}
boolean expires() {
return expiresAfterWrite() || expiresAfterAccess();
}
boolean expiresAfterWrite() {
return expireAfterWriteNanos > 0;
}
boolean expiresAfterAccess() {
return expireAfterAccessNanos > 0;
}
boolean usesKeyReferences() {
return keyStrength != Strength.STRONG;
}
boolean usesValueReferences() {
return valueStrength != Strength.STRONG;
}
enum Strength {
/*
* TODO(kevinb): If we strongly reference the value and aren't computing, we needn't wrap the
* value. This could save ~8 bytes per entry.
*/
STRONG {
@Override
<K, V> ValueReference<K, V> referenceValue(
Segment<K, V> segment, ReferenceEntry<K, V> entry, V value) {
return new StrongValueReference<K, V>(value);
}
@Override
Equivalence<Object> defaultEquivalence() {
return Equivalences.equals();
}
},
SOFT {
@Override
<K, V> ValueReference<K, V> referenceValue(
Segment<K, V> segment, ReferenceEntry<K, V> entry, V value) {
return new SoftValueReference<K, V>(segment.valueReferenceQueue, value, entry);
}
@Override
Equivalence<Object> defaultEquivalence() {
return Equivalences.identity();
}
},
WEAK {
@Override
<K, V> ValueReference<K, V> referenceValue(
Segment<K, V> segment, ReferenceEntry<K, V> entry, V value) {
return new WeakValueReference<K, V>(segment.valueReferenceQueue, value, entry);
}
@Override
Equivalence<Object> defaultEquivalence() {
return Equivalences.identity();
}
};
/**
* Creates a reference for the given value according to this value strength.
*/
abstract <K, V> ValueReference<K, V> referenceValue(
Segment<K, V> segment, ReferenceEntry<K, V> entry, V value);
/**
* Returns the default equivalence strategy used to compare and hash keys or values referenced
* at this strength. This strategy will be used unless the user explicitly specifies an
* alternate strategy.
*/
abstract Equivalence<Object> defaultEquivalence();
}
/**
* Creates new entries.
*/
enum EntryFactory {
STRONG {
@Override
<K, V> ReferenceEntry<K, V> newEntry(
Segment<K, V> segment, K key, int hash, @Nullable ReferenceEntry<K, V> next) {
return new StrongEntry<K, V>(key, hash, next);
}
},
STRONG_EXPIRABLE {
@Override
<K, V> ReferenceEntry<K, V> newEntry(
Segment<K, V> segment, K key, int hash, @Nullable ReferenceEntry<K, V> next) {
return new StrongExpirableEntry<K, V>(key, hash, next);
}
@Override
<K, V> ReferenceEntry<K, V> copyEntry(
Segment<K, V> segment, ReferenceEntry<K, V> original, ReferenceEntry<K, V> newNext) {
ReferenceEntry<K, V> newEntry = super.copyEntry(segment, original, newNext);
copyExpirableEntry(original, newEntry);
return newEntry;
}
},
STRONG_EVICTABLE {
@Override
<K, V> ReferenceEntry<K, V> newEntry(
Segment<K, V> segment, K key, int hash, @Nullable ReferenceEntry<K, V> next) {
return new StrongEvictableEntry<K, V>(key, hash, next);
}
@Override
<K, V> ReferenceEntry<K, V> copyEntry(
Segment<K, V> segment, ReferenceEntry<K, V> original, ReferenceEntry<K, V> newNext) {
ReferenceEntry<K, V> newEntry = super.copyEntry(segment, original, newNext);
copyEvictableEntry(original, newEntry);
return newEntry;
}
},
STRONG_EXPIRABLE_EVICTABLE {
@Override
<K, V> ReferenceEntry<K, V> newEntry(
Segment<K, V> segment, K key, int hash, @Nullable ReferenceEntry<K, V> next) {
return new StrongExpirableEvictableEntry<K, V>(key, hash, next);
}
@Override
<K, V> ReferenceEntry<K, V> copyEntry(
Segment<K, V> segment, ReferenceEntry<K, V> original, ReferenceEntry<K, V> newNext) {
ReferenceEntry<K, V> newEntry = super.copyEntry(segment, original, newNext);
copyExpirableEntry(original, newEntry);
copyEvictableEntry(original, newEntry);
return newEntry;
}
},
SOFT {
@Override
<K, V> ReferenceEntry<K, V> newEntry(
Segment<K, V> segment, K key, int hash, @Nullable ReferenceEntry<K, V> next) {
return new SoftEntry<K, V>(segment.keyReferenceQueue, key, hash, next);
}
},
SOFT_EXPIRABLE {
@Override
<K, V> ReferenceEntry<K, V> newEntry(
Segment<K, V> segment, K key, int hash, @Nullable ReferenceEntry<K, V> next) {
return new SoftExpirableEntry<K, V>(segment.keyReferenceQueue, key, hash, next);
}
@Override
<K, V> ReferenceEntry<K, V> copyEntry(
Segment<K, V> segment, ReferenceEntry<K, V> original, ReferenceEntry<K, V> newNext) {
ReferenceEntry<K, V> newEntry = super.copyEntry(segment, original, newNext);
copyExpirableEntry(original, newEntry);
return newEntry;
}
},
SOFT_EVICTABLE {
@Override
<K, V> ReferenceEntry<K, V> newEntry(
Segment<K, V> segment, K key, int hash, @Nullable ReferenceEntry<K, V> next) {
return new SoftEvictableEntry<K, V>(segment.keyReferenceQueue, key, hash, next);
}
@Override
<K, V> ReferenceEntry<K, V> copyEntry(
Segment<K, V> segment, ReferenceEntry<K, V> original, ReferenceEntry<K, V> newNext) {
ReferenceEntry<K, V> newEntry = super.copyEntry(segment, original, newNext);
copyEvictableEntry(original, newEntry);
return newEntry;
}
},
SOFT_EXPIRABLE_EVICTABLE {
@Override
<K, V> ReferenceEntry<K, V> newEntry(
Segment<K, V> segment, K key, int hash, @Nullable ReferenceEntry<K, V> next) {
return new SoftExpirableEvictableEntry<K, V>(segment.keyReferenceQueue, key, hash, next);
}
@Override
<K, V> ReferenceEntry<K, V> copyEntry(
Segment<K, V> segment, ReferenceEntry<K, V> original, ReferenceEntry<K, V> newNext) {
ReferenceEntry<K, V> newEntry = super.copyEntry(segment, original, newNext);
copyExpirableEntry(original, newEntry);
copyEvictableEntry(original, newEntry);
return newEntry;
}
},
WEAK {
@Override
<K, V> ReferenceEntry<K, V> newEntry(
Segment<K, V> segment, K key, int hash, @Nullable ReferenceEntry<K, V> next) {
return new WeakEntry<K, V>(segment.keyReferenceQueue, key, hash, next);
}
},
WEAK_EXPIRABLE {
@Override
<K, V> ReferenceEntry<K, V> newEntry(
Segment<K, V> segment, K key, int hash, @Nullable ReferenceEntry<K, V> next) {
return new WeakExpirableEntry<K, V>(segment.keyReferenceQueue, key, hash, next);
}
@Override
<K, V> ReferenceEntry<K, V> copyEntry(
Segment<K, V> segment, ReferenceEntry<K, V> original, ReferenceEntry<K, V> newNext) {
ReferenceEntry<K, V> newEntry = super.copyEntry(segment, original, newNext);
copyExpirableEntry(original, newEntry);
return newEntry;
}
},
WEAK_EVICTABLE {
@Override
<K, V> ReferenceEntry<K, V> newEntry(
Segment<K, V> segment, K key, int hash, @Nullable ReferenceEntry<K, V> next) {
return new WeakEvictableEntry<K, V>(segment.keyReferenceQueue, key, hash, next);
}
@Override
<K, V> ReferenceEntry<K, V> copyEntry(
Segment<K, V> segment, ReferenceEntry<K, V> original, ReferenceEntry<K, V> newNext) {
ReferenceEntry<K, V> newEntry = super.copyEntry(segment, original, newNext);
copyEvictableEntry(original, newEntry);
return newEntry;
}
},
WEAK_EXPIRABLE_EVICTABLE {
@Override
<K, V> ReferenceEntry<K, V> newEntry(
Segment<K, V> segment, K key, int hash, @Nullable ReferenceEntry<K, V> next) {
return new WeakExpirableEvictableEntry<K, V>(segment.keyReferenceQueue, key, hash, next);
}
@Override
<K, V> ReferenceEntry<K, V> copyEntry(
Segment<K, V> segment, ReferenceEntry<K, V> original, ReferenceEntry<K, V> newNext) {
ReferenceEntry<K, V> newEntry = super.copyEntry(segment, original, newNext);
copyExpirableEntry(original, newEntry);
copyEvictableEntry(original, newEntry);
return newEntry;
}
};
/**
* Masks used to compute indices in the following table.
*/
static final int EXPIRABLE_MASK = 1;
static final int EVICTABLE_MASK = 2;
/**
* Look-up table for factories. First dimension is the reference type. The second dimension is
* the result of OR-ing the feature masks.
*/
static final EntryFactory[][] factories = {
{ STRONG, STRONG_EXPIRABLE, STRONG_EVICTABLE, STRONG_EXPIRABLE_EVICTABLE },
{ SOFT, SOFT_EXPIRABLE, SOFT_EVICTABLE, SOFT_EXPIRABLE_EVICTABLE },
{ WEAK, WEAK_EXPIRABLE, WEAK_EVICTABLE, WEAK_EXPIRABLE_EVICTABLE }
};
static EntryFactory getFactory(Strength keyStrength, boolean expireAfterWrite,
boolean evictsBySize) {
int flags = (expireAfterWrite ? EXPIRABLE_MASK : 0) | (evictsBySize ? EVICTABLE_MASK : 0);
return factories[keyStrength.ordinal()][flags];
}
/**
* Creates a new entry.
*
* @param segment to create the entry for
* @param key of the entry
* @param hash of the key
* @param next entry in the same bucket
*/
abstract <K, V> ReferenceEntry<K, V> newEntry(
Segment<K, V> segment, K key, int hash, @Nullable ReferenceEntry<K, V> next);
/**
* Copies an entry, assigning it a new {@code next} entry.
*
* @param original the entry to copy
* @param newNext entry in the same bucket
*/
@GuardedBy("Segment.this")
<K, V> ReferenceEntry<K, V> copyEntry(
Segment<K, V> segment, ReferenceEntry<K, V> original, ReferenceEntry<K, V> newNext) {
return newEntry(segment, original.getKey(), original.getHash(), newNext);
}
@GuardedBy("Segment.this")
<K, V> void copyExpirableEntry(ReferenceEntry<K, V> original, ReferenceEntry<K, V> newEntry) {
// TODO(fry): when we link values instead of entries this method can go
// away, as can connectExpirables, nullifyExpirable.
newEntry.setExpirationTime(original.getExpirationTime());
connectExpirables(original.getPreviousExpirable(), newEntry);
connectExpirables(newEntry, original.getNextExpirable());
nullifyExpirable(original);
}
@GuardedBy("Segment.this")
<K, V> void copyEvictableEntry(ReferenceEntry<K, V> original, ReferenceEntry<K, V> newEntry) {
// TODO(fry): when we link values instead of entries this method can go
// away, as can connectEvictables, nullifyEvictable.
connectEvictables(original.getPreviousEvictable(), newEntry);
connectEvictables(newEntry, original.getNextEvictable());
nullifyEvictable(original);
}
}
/**
* A reference to a value.
*/
interface ValueReference<K, V> {
/**
* Gets the value. Does not block or throw exceptions.
*/
V get();
/**
* Waits for a value that may still be computing. Unlike get(), this method can block (in the
* case of FutureValueReference).
*
* @throws ExecutionException if the computing thread throws an exception
*/
V waitForValue() throws ExecutionException;
/**
* Returns the entry associated with this value reference, or {@code null} if this value
* reference is independent of any entry.
*/
ReferenceEntry<K, V> getEntry();
/**
* Creates a copy of this reference for the given entry.
*/
ValueReference<K, V> copyFor(ReferenceQueue<V> queue, ReferenceEntry<K, V> entry);
/**
* Clears this reference object.
*
* @param newValue the new value reference which will replace this one; this is only used during
* computation to immediately notify blocked threads of the new value
*/
void clear(@Nullable ValueReference<K, V> newValue);
/**
* Returns {@code true} if the value type is a computing reference (regardless of whether or not
* computation has completed). This is necessary to distiguish between partially-collected
* entries and computing entries, which need to be cleaned up differently.
*/
boolean isComputingReference();
}
/**
* Placeholder. Indicates that the value hasn't been set yet.
*/
static final ValueReference<Object, Object> UNSET = new ValueReference<Object, Object>() {
@Override
public Object get() {
return null;
}
@Override
public ReferenceEntry<Object, Object> getEntry() {
return null;
}
@Override
public ValueReference<Object, Object> copyFor(
ReferenceQueue<Object> queue, ReferenceEntry<Object, Object> entry) {
return this;
}
@Override
public boolean isComputingReference() {
return false;
}
@Override
public Object waitForValue() {
return null;
}
@Override
public void clear(ValueReference<Object, Object> newValue) {}
};
/**
* Singleton placeholder that indicates a value is being computed.
*/
@SuppressWarnings("unchecked") // impl never uses a parameter or returns any non-null value
static <K, V> ValueReference<K, V> unset() {
return (ValueReference<K, V>) UNSET;
}
/**
* An entry in a reference map.
*
* Entries in the map can be in the following states:
*
* Valid:
* - Live: valid key/value are set
* - Computing: computation is pending
*
* Invalid:
* - Expired: time expired (key/value may still be set)
* - Collected: key/value was partially collected, but not yet cleaned up
*/
interface ReferenceEntry<K, V> {
/**
* Gets the value reference from this entry.
*/
ValueReference<K, V> getValueReference();
/**
* Sets the value reference for this entry.
*/
void setValueReference(ValueReference<K, V> valueReference);
/**
* Gets the next entry in the chain.
*/
ReferenceEntry<K, V> getNext();
/**
* Gets the entry's hash.
*/
int getHash();
/**
* Gets the key for this entry.
*/
K getKey();
/*
* Used by entries that are expirable. Expirable entries are maintained in a doubly-linked list.
* New entries are added at the tail of the list at write time; stale entries are expired from
* the head of the list.
*/
/**
* Gets the entry expiration time in ns.
*/
long getExpirationTime();
/**
* Sets the entry expiration time in ns.
*/
void setExpirationTime(long time);
/**
* Gets the next entry in the recency list.
*/
ReferenceEntry<K, V> getNextExpirable();
/**
* Sets the next entry in the recency list.
*/
void setNextExpirable(ReferenceEntry<K, V> next);
/**
* Gets the previous entry in the recency list.
*/
ReferenceEntry<K, V> getPreviousExpirable();
/**
* Sets the previous entry in the recency list.
*/
void setPreviousExpirable(ReferenceEntry<K, V> previous);
/*
* Implemented by entries that are evictable. Evictable entries are maintained in a
* doubly-linked list. New entries are added at the tail of the list at write time and stale
* entries are expired from the head of the list.
*/
/**
* Gets the next entry in the recency list.
*/
ReferenceEntry<K, V> getNextEvictable();
/**
* Sets the next entry in the recency list.
*/
void setNextEvictable(ReferenceEntry<K, V> next);
/**
* Gets the previous entry in the recency list.
*/
ReferenceEntry<K, V> getPreviousEvictable();
/**
* Sets the previous entry in the recency list.
*/
void setPreviousEvictable(ReferenceEntry<K, V> previous);
}
private enum NullEntry implements ReferenceEntry<Object, Object> {
INSTANCE;
@Override
public ValueReference<Object, Object> getValueReference() {
return null;
}
@Override
public void setValueReference(ValueReference<Object, Object> valueReference) {}
@Override
public ReferenceEntry<Object, Object> getNext() {
return null;
}
@Override
public int getHash() {
return 0;
}
@Override
public Object getKey() {
return null;
}
@Override
public long getExpirationTime() {
return 0;
}
@Override
public void setExpirationTime(long time) {}
@Override
public ReferenceEntry<Object, Object> getNextExpirable() {
return this;
}
@Override
public void setNextExpirable(ReferenceEntry<Object, Object> next) {}
@Override
public ReferenceEntry<Object, Object> getPreviousExpirable() {
return this;
}
@Override
public void setPreviousExpirable(ReferenceEntry<Object, Object> previous) {}
@Override
public ReferenceEntry<Object, Object> getNextEvictable() {
return this;
}
@Override
public void setNextEvictable(ReferenceEntry<Object, Object> next) {}
@Override
public ReferenceEntry<Object, Object> getPreviousEvictable() {
return this;
}
@Override
public void setPreviousEvictable(ReferenceEntry<Object, Object> previous) {}
}
static abstract class AbstractReferenceEntry<K, V> implements ReferenceEntry<K, V> {
@Override
public ValueReference<K, V> getValueReference() {
throw new UnsupportedOperationException();
}
@Override
public void setValueReference(ValueReference<K, V> valueReference) {
throw new UnsupportedOperationException();
}
@Override
public ReferenceEntry<K, V> getNext() {
throw new UnsupportedOperationException();
}
@Override
public int getHash() {
throw new UnsupportedOperationException();
}
@Override
public K getKey() {
throw new UnsupportedOperationException();
}
@Override
public long getExpirationTime() {
throw new UnsupportedOperationException();
}
@Override
public void setExpirationTime(long time) {
throw new UnsupportedOperationException();
}
@Override
public ReferenceEntry<K, V> getNextExpirable() {
throw new UnsupportedOperationException();
}
@Override
public void setNextExpirable(ReferenceEntry<K, V> next) {
throw new UnsupportedOperationException();
}
@Override
public ReferenceEntry<K, V> getPreviousExpirable() {
throw new UnsupportedOperationException();
}
@Override
public void setPreviousExpirable(ReferenceEntry<K, V> previous) {
throw new UnsupportedOperationException();
}
@Override
public ReferenceEntry<K, V> getNextEvictable() {
throw new UnsupportedOperationException();
}
@Override
public void setNextEvictable(ReferenceEntry<K, V> next) {
throw new UnsupportedOperationException();
}
@Override
public ReferenceEntry<K, V> getPreviousEvictable() {
throw new UnsupportedOperationException();
}
@Override
public void setPreviousEvictable(ReferenceEntry<K, V> previous) {
throw new UnsupportedOperationException();
}
}
@SuppressWarnings("unchecked") // impl never uses a parameter or returns any non-null value
static <K, V> ReferenceEntry<K, V> nullEntry() {
return (ReferenceEntry<K, V>) NullEntry.INSTANCE;
}
static final Queue<? extends Object> DISCARDING_QUEUE = new AbstractQueue<Object>() {
@Override
public boolean offer(Object o) {
return true;
}
@Override
public Object peek() {
return null;
}
@Override
public Object poll() {
return null;
}
@Override
public int size() {
return 0;
}
@Override
public Iterator<Object> iterator() {
return Iterators.emptyIterator();
}
};
/**
* Queue that discards all elements.
*/
@SuppressWarnings("unchecked") // impl never uses a parameter or returns any non-null value
static <E> Queue<E> discardingQueue() {
return (Queue) DISCARDING_QUEUE;
}
/*
* Note: All of this duplicate code sucks, but it saves a lot of memory. If only Java had mixins!
* To maintain this code, make a change for the strong reference type. Then, cut and paste, and
* replace "Strong" with "Soft" or "Weak" within the pasted text. The primary difference is that
* strong entries store the key reference directly while soft and weak entries delegate to their
* respective superclasses.
*/
/**
* Used for strongly-referenced keys.
*/
static class StrongEntry<K, V> implements ReferenceEntry<K, V> {
final K key;
StrongEntry(K key, int hash, @Nullable ReferenceEntry<K, V> next) {
this.key = key;
this.hash = hash;
this.next = next;
}
@Override
public K getKey() {
return this.key;
}
// null expiration
@Override
public long getExpirationTime() {
throw new UnsupportedOperationException();
}
@Override
public void setExpirationTime(long time) {
throw new UnsupportedOperationException();
}
@Override
public ReferenceEntry<K, V> getNextExpirable() {
throw new UnsupportedOperationException();
}
@Override
public void setNextExpirable(ReferenceEntry<K, V> next) {
throw new UnsupportedOperationException();
}
@Override
public ReferenceEntry<K, V> getPreviousExpirable() {
throw new UnsupportedOperationException();
}
@Override
public void setPreviousExpirable(ReferenceEntry<K, V> previous) {
throw new UnsupportedOperationException();
}
// null eviction
@Override
public ReferenceEntry<K, V> getNextEvictable() {
throw new UnsupportedOperationException();
}
@Override
public void setNextEvictable(ReferenceEntry<K, V> next) {
throw new UnsupportedOperationException();
}
@Override
public ReferenceEntry<K, V> getPreviousEvictable() {
throw new UnsupportedOperationException();
}
@Override
public void setPreviousEvictable(ReferenceEntry<K, V> previous) {
throw new UnsupportedOperationException();
}
// The code below is exactly the same for each entry type.
final int hash;
final ReferenceEntry<K, V> next;
volatile ValueReference<K, V> valueReference = unset();
@Override
public ValueReference<K, V> getValueReference() {
return valueReference;
}
@Override
public void setValueReference(ValueReference<K, V> valueReference) {
ValueReference<K, V> previous = this.valueReference;
this.valueReference = valueReference;
previous.clear(valueReference);
}
@Override
public int getHash() {
return hash;
}
@Override
public ReferenceEntry<K, V> getNext() {
return next;
}
}
static final class StrongExpirableEntry<K, V> extends StrongEntry<K, V>
implements ReferenceEntry<K, V> {
StrongExpirableEntry(K key, int hash, @Nullable ReferenceEntry<K, V> next) {
super(key, hash, next);
}
// The code below is exactly the same for each expirable entry type.
volatile long time = Long.MAX_VALUE;
@Override
public long getExpirationTime() {
return time;
}
@Override
public void setExpirationTime(long time) {
this.time = time;
}
@GuardedBy("Segment.this")
ReferenceEntry<K, V> nextExpirable = nullEntry();
@Override
public ReferenceEntry<K, V> getNextExpirable() {
return nextExpirable;
}
@Override
public void setNextExpirable(ReferenceEntry<K, V> next) {
this.nextExpirable = next;
}
@GuardedBy("Segment.this")
ReferenceEntry<K, V> previousExpirable = nullEntry();
@Override
public ReferenceEntry<K, V> getPreviousExpirable() {
return previousExpirable;
}
@Override
public void setPreviousExpirable(ReferenceEntry<K, V> previous) {
this.previousExpirable = previous;
}
}
static final class StrongEvictableEntry<K, V>
extends StrongEntry<K, V> implements ReferenceEntry<K, V> {
StrongEvictableEntry(K key, int hash, @Nullable ReferenceEntry<K, V> next) {
super(key, hash, next);
}
// The code below is exactly the same for each evictable entry type.
@GuardedBy("Segment.this")
ReferenceEntry<K, V> nextEvictable = nullEntry();
@Override
public ReferenceEntry<K, V> getNextEvictable() {
return nextEvictable;
}
@Override
public void setNextEvictable(ReferenceEntry<K, V> next) {
this.nextEvictable = next;
}
@GuardedBy("Segment.this")
ReferenceEntry<K, V> previousEvictable = nullEntry();
@Override
public ReferenceEntry<K, V> getPreviousEvictable() {
return previousEvictable;
}
@Override
public void setPreviousEvictable(ReferenceEntry<K, V> previous) {
this.previousEvictable = previous;
}
}
static final class StrongExpirableEvictableEntry<K, V>
extends StrongEntry<K, V> implements ReferenceEntry<K, V> {
StrongExpirableEvictableEntry(K key, int hash, @Nullable ReferenceEntry<K, V> next) {
super(key, hash, next);
}
// The code below is exactly the same for each expirable entry type.
volatile long time = Long.MAX_VALUE;
@Override
public long getExpirationTime() {
return time;
}
@Override
public void setExpirationTime(long time) {
this.time = time;
}
@GuardedBy("Segment.this")
ReferenceEntry<K, V> nextExpirable = nullEntry();
@Override
public ReferenceEntry<K, V> getNextExpirable() {
return nextExpirable;
}
@Override
public void setNextExpirable(ReferenceEntry<K, V> next) {
this.nextExpirable = next;
}
@GuardedBy("Segment.this")
ReferenceEntry<K, V> previousExpirable = nullEntry();
@Override
public ReferenceEntry<K, V> getPreviousExpirable() {
return previousExpirable;
}
@Override
public void setPreviousExpirable(ReferenceEntry<K, V> previous) {
this.previousExpirable = previous;
}
// The code below is exactly the same for each evictable entry type.
@GuardedBy("Segment.this")
ReferenceEntry<K, V> nextEvictable = nullEntry();
@Override
public ReferenceEntry<K, V> getNextEvictable() {
return nextEvictable;
}
@Override
public void setNextEvictable(ReferenceEntry<K, V> next) {
this.nextEvictable = next;
}
@GuardedBy("Segment.this")
ReferenceEntry<K, V> previousEvictable = nullEntry();
@Override
public ReferenceEntry<K, V> getPreviousEvictable() {
return previousEvictable;
}
@Override
public void setPreviousEvictable(ReferenceEntry<K, V> previous) {
this.previousEvictable = previous;
}
}
/**
* Used for softly-referenced keys.
*/
static class SoftEntry<K, V> extends SoftReference<K> implements ReferenceEntry<K, V> {
SoftEntry(ReferenceQueue<K> queue, K key, int hash, @Nullable ReferenceEntry<K, V> next) {
super(key, queue);
this.hash = hash;
this.next = next;
}
@Override
public K getKey() {
return get();
}
// null expiration
@Override
public long getExpirationTime() {
throw new UnsupportedOperationException();
}
@Override
public void setExpirationTime(long time) {
throw new UnsupportedOperationException();
}
@Override
public ReferenceEntry<K, V> getNextExpirable() {
throw new UnsupportedOperationException();
}
@Override
public void setNextExpirable(ReferenceEntry<K, V> next) {
throw new UnsupportedOperationException();
}
@Override
public ReferenceEntry<K, V> getPreviousExpirable() {
throw new UnsupportedOperationException();
}
@Override
public void setPreviousExpirable(ReferenceEntry<K, V> previous) {
throw new UnsupportedOperationException();
}
// null eviction
@Override
public ReferenceEntry<K, V> getNextEvictable() {
throw new UnsupportedOperationException();
}
@Override
public void setNextEvictable(ReferenceEntry<K, V> next) {
throw new UnsupportedOperationException();
}
@Override
public ReferenceEntry<K, V> getPreviousEvictable() {
throw new UnsupportedOperationException();
}
@Override
public void setPreviousEvictable(ReferenceEntry<K, V> previous) {
throw new UnsupportedOperationException();
}
// The code below is exactly the same for each entry type.
final int hash;
final ReferenceEntry<K, V> next;
volatile ValueReference<K, V> valueReference = unset();
@Override
public ValueReference<K, V> getValueReference() {
return valueReference;
}
@Override
public void setValueReference(ValueReference<K, V> valueReference) {
ValueReference<K, V> previous = this.valueReference;
this.valueReference = valueReference;
previous.clear(valueReference);
}
@Override
public int getHash() {
return hash;
}
@Override
public ReferenceEntry<K, V> getNext() {
return next;
}
}
static final class SoftExpirableEntry<K, V>
extends SoftEntry<K, V> implements ReferenceEntry<K, V> {
SoftExpirableEntry(
ReferenceQueue<K> queue, K key, int hash, @Nullable ReferenceEntry<K, V> next) {
super(queue, key, hash, next);
}
// The code below is exactly the same for each expirable entry type.
volatile long time = Long.MAX_VALUE;
@Override
public long getExpirationTime() {
return time;
}
@Override
public void setExpirationTime(long time) {
this.time = time;
}
@GuardedBy("Segment.this")
ReferenceEntry<K, V> nextExpirable = nullEntry();
@Override
public ReferenceEntry<K, V> getNextExpirable() {
return nextExpirable;
}
@Override
public void setNextExpirable(ReferenceEntry<K, V> next) {
this.nextExpirable = next;
}
@GuardedBy("Segment.this")
ReferenceEntry<K, V> previousExpirable = nullEntry();
@Override
public ReferenceEntry<K, V> getPreviousExpirable() {
return previousExpirable;
}
@Override
public void setPreviousExpirable(ReferenceEntry<K, V> previous) {
this.previousExpirable = previous;
}
}
static final class SoftEvictableEntry<K, V>
extends SoftEntry<K, V> implements ReferenceEntry<K, V> {
SoftEvictableEntry(
ReferenceQueue<K> queue, K key, int hash, @Nullable ReferenceEntry<K, V> next) {
super(queue, key, hash, next);
}
// The code below is exactly the same for each evictable entry type.
@GuardedBy("Segment.this")
ReferenceEntry<K, V> nextEvictable = nullEntry();
@Override
public ReferenceEntry<K, V> getNextEvictable() {
return nextEvictable;
}
@Override
public void setNextEvictable(ReferenceEntry<K, V> next) {
this.nextEvictable = next;
}
@GuardedBy("Segment.this")
ReferenceEntry<K, V> previousEvictable = nullEntry();
@Override
public ReferenceEntry<K, V> getPreviousEvictable() {
return previousEvictable;
}
@Override
public void setPreviousEvictable(ReferenceEntry<K, V> previous) {
this.previousEvictable = previous;
}
}
static final class SoftExpirableEvictableEntry<K, V>
extends SoftEntry<K, V> implements ReferenceEntry<K, V> {
SoftExpirableEvictableEntry(
ReferenceQueue<K> queue, K key, int hash, @Nullable ReferenceEntry<K, V> next) {
super(queue, key, hash, next);
}
// The code below is exactly the same for each expirable entry type.
volatile long time = Long.MAX_VALUE;
@Override
public long getExpirationTime() {
return time;
}
@Override
public void setExpirationTime(long time) {
this.time = time;
}
@GuardedBy("Segment.this")
ReferenceEntry<K, V> nextExpirable = nullEntry();
@Override
public ReferenceEntry<K, V> getNextExpirable() {
return nextExpirable;
}
@Override
public void setNextExpirable(ReferenceEntry<K, V> next) {
this.nextExpirable = next;
}
@GuardedBy("Segment.this")
ReferenceEntry<K, V> previousExpirable = nullEntry();
@Override
public ReferenceEntry<K, V> getPreviousExpirable() {
return previousExpirable;
}
@Override
public void setPreviousExpirable(ReferenceEntry<K, V> previous) {
this.previousExpirable = previous;
}
// The code below is exactly the same for each evictable entry type.
@GuardedBy("Segment.this")
ReferenceEntry<K, V> nextEvictable = nullEntry();
@Override
public ReferenceEntry<K, V> getNextEvictable() {
return nextEvictable;
}
@Override
public void setNextEvictable(ReferenceEntry<K, V> next) {
this.nextEvictable = next;
}
@GuardedBy("Segment.this")
ReferenceEntry<K, V> previousEvictable = nullEntry();
@Override
public ReferenceEntry<K, V> getPreviousEvictable() {
return previousEvictable;
}
@Override
public void setPreviousEvictable(ReferenceEntry<K, V> previous) {
this.previousEvictable = previous;
}
}
/**
* Used for weakly-referenced keys.
*/
static class WeakEntry<K, V> extends WeakReference<K> implements ReferenceEntry<K, V> {
WeakEntry(ReferenceQueue<K> queue, K key, int hash, @Nullable ReferenceEntry<K, V> next) {
super(key, queue);
this.hash = hash;
this.next = next;
}
@Override
public K getKey() {
return get();
}
// null expiration
@Override
public long getExpirationTime() {
throw new UnsupportedOperationException();
}
@Override
public void setExpirationTime(long time) {
throw new UnsupportedOperationException();
}
@Override
public ReferenceEntry<K, V> getNextExpirable() {
throw new UnsupportedOperationException();
}
@Override
public void setNextExpirable(ReferenceEntry<K, V> next) {
throw new UnsupportedOperationException();
}
@Override
public ReferenceEntry<K, V> getPreviousExpirable() {
throw new UnsupportedOperationException();
}
@Override
public void setPreviousExpirable(ReferenceEntry<K, V> previous) {
throw new UnsupportedOperationException();
}
// null eviction
@Override
public ReferenceEntry<K, V> getNextEvictable() {
throw new UnsupportedOperationException();
}
@Override
public void setNextEvictable(ReferenceEntry<K, V> next) {
throw new UnsupportedOperationException();
}
@Override
public ReferenceEntry<K, V> getPreviousEvictable() {
throw new UnsupportedOperationException();
}
@Override
public void setPreviousEvictable(ReferenceEntry<K, V> previous) {
throw new UnsupportedOperationException();
}
// The code below is exactly the same for each entry type.
final int hash;
final ReferenceEntry<K, V> next;
volatile ValueReference<K, V> valueReference = unset();
@Override
public ValueReference<K, V> getValueReference() {
return valueReference;
}
@Override
public void setValueReference(ValueReference<K, V> valueReference) {
ValueReference<K, V> previous = this.valueReference;
this.valueReference = valueReference;
previous.clear(valueReference);
}
@Override
public int getHash() {
return hash;
}
@Override
public ReferenceEntry<K, V> getNext() {
return next;
}
}
static final class WeakExpirableEntry<K, V>
extends WeakEntry<K, V> implements ReferenceEntry<K, V> {
WeakExpirableEntry(
ReferenceQueue<K> queue, K key, int hash, @Nullable ReferenceEntry<K, V> next) {
super(queue, key, hash, next);
}
// The code below is exactly the same for each expirable entry type.
volatile long time = Long.MAX_VALUE;
@Override
public long getExpirationTime() {
return time;
}
@Override
public void setExpirationTime(long time) {
this.time = time;
}
@GuardedBy("Segment.this")
ReferenceEntry<K, V> nextExpirable = nullEntry();
@Override
public ReferenceEntry<K, V> getNextExpirable() {
return nextExpirable;
}
@Override
public void setNextExpirable(ReferenceEntry<K, V> next) {
this.nextExpirable = next;
}
@GuardedBy("Segment.this")
ReferenceEntry<K, V> previousExpirable = nullEntry();
@Override
public ReferenceEntry<K, V> getPreviousExpirable() {
return previousExpirable;
}
@Override
public void setPreviousExpirable(ReferenceEntry<K, V> previous) {
this.previousExpirable = previous;
}
}
static final class WeakEvictableEntry<K, V>
extends WeakEntry<K, V> implements ReferenceEntry<K, V> {
WeakEvictableEntry(
ReferenceQueue<K> queue, K key, int hash, @Nullable ReferenceEntry<K, V> next) {
super(queue, key, hash, next);
}
// The code below is exactly the same for each evictable entry type.
@GuardedBy("Segment.this")
ReferenceEntry<K, V> nextEvictable = nullEntry();
@Override
public ReferenceEntry<K, V> getNextEvictable() {
return nextEvictable;
}
@Override
public void setNextEvictable(ReferenceEntry<K, V> next) {
this.nextEvictable = next;
}
@GuardedBy("Segment.this")
ReferenceEntry<K, V> previousEvictable = nullEntry();
@Override
public ReferenceEntry<K, V> getPreviousEvictable() {
return previousEvictable;
}
@Override
public void setPreviousEvictable(ReferenceEntry<K, V> previous) {
this.previousEvictable = previous;
}
}
static final class WeakExpirableEvictableEntry<K, V>
extends WeakEntry<K, V> implements ReferenceEntry<K, V> {
WeakExpirableEvictableEntry(
ReferenceQueue<K> queue, K key, int hash, @Nullable ReferenceEntry<K, V> next) {
super(queue, key, hash, next);
}
// The code below is exactly the same for each expirable entry type.
volatile long time = Long.MAX_VALUE;
@Override
public long getExpirationTime() {
return time;
}
@Override
public void setExpirationTime(long time) {
this.time = time;
}
@GuardedBy("Segment.this")
ReferenceEntry<K, V> nextExpirable = nullEntry();
@Override
public ReferenceEntry<K, V> getNextExpirable() {
return nextExpirable;
}
@Override
public void setNextExpirable(ReferenceEntry<K, V> next) {
this.nextExpirable = next;
}
@GuardedBy("Segment.this")
ReferenceEntry<K, V> previousExpirable = nullEntry();
@Override
public ReferenceEntry<K, V> getPreviousExpirable() {
return previousExpirable;
}
@Override
public void setPreviousExpirable(ReferenceEntry<K, V> previous) {
this.previousExpirable = previous;
}
// The code below is exactly the same for each evictable entry type.
@GuardedBy("Segment.this")
ReferenceEntry<K, V> nextEvictable = nullEntry();
@Override
public ReferenceEntry<K, V> getNextEvictable() {
return nextEvictable;
}
@Override
public void setNextEvictable(ReferenceEntry<K, V> next) {
this.nextEvictable = next;
}
@GuardedBy("Segment.this")
ReferenceEntry<K, V> previousEvictable = nullEntry();
@Override
public ReferenceEntry<K, V> getPreviousEvictable() {
return previousEvictable;
}
@Override
public void setPreviousEvictable(ReferenceEntry<K, V> previous) {
this.previousEvictable = previous;
}
}
/**
* References a weak value.
*/
static final class WeakValueReference<K, V>
extends WeakReference<V> implements ValueReference<K, V> {
final ReferenceEntry<K, V> entry;
WeakValueReference(ReferenceQueue<V> queue, V referent, ReferenceEntry<K, V> entry) {
super(referent, queue);
this.entry = entry;
}
@Override
public ReferenceEntry<K, V> getEntry() {
return entry;
}
@Override
public void clear(ValueReference<K, V> newValue) {
clear();
}
@Override
public ValueReference<K, V> copyFor(
ReferenceQueue<V> queue, ReferenceEntry<K, V> entry) {
return new WeakValueReference<K, V>(queue, get(), entry);
}
@Override
public boolean isComputingReference() {
return false;
}
@Override
public V waitForValue() {
return get();
}
}
/**
* References a soft value.
*/
static final class SoftValueReference<K, V>
extends SoftReference<V> implements ValueReference<K, V> {
final ReferenceEntry<K, V> entry;
SoftValueReference(ReferenceQueue<V> queue, V referent, ReferenceEntry<K, V> entry) {
super(referent, queue);
this.entry = entry;
}
@Override
public ReferenceEntry<K, V> getEntry() {
return entry;
}
@Override
public void clear(ValueReference<K, V> newValue) {
clear();
}
@Override
public ValueReference<K, V> copyFor(ReferenceQueue<V> queue, ReferenceEntry<K, V> entry) {
return new SoftValueReference<K, V>(queue, get(), entry);
}
@Override
public boolean isComputingReference() {
return false;
}
@Override
public V waitForValue() {
return get();
}
}
/**
* References a strong value.
*/
static final class StrongValueReference<K, V> implements ValueReference<K, V> {
final V referent;
StrongValueReference(V referent) {
this.referent = referent;
}
@Override
public V get() {
return referent;
}
@Override
public ReferenceEntry<K, V> getEntry() {
return null;
}
@Override
public ValueReference<K, V> copyFor(ReferenceQueue<V> queue, ReferenceEntry<K, V> entry) {
return this;
}
@Override
public boolean isComputingReference() {
return false;
}
@Override
public V waitForValue() {
return get();
}
@Override
public void clear(ValueReference<K, V> newValue) {}
}
/**
* Applies a supplemental hash function to a given hash code, which defends against poor quality
* hash functions. This is critical when the concurrent hash map uses power-of-two length hash
* tables, that otherwise encounter collisions for hash codes that do not differ in lower or
* upper bits.
*
* @param h hash code
*/
static int rehash(int h) {
// Spread bits to regularize both segment and index locations,
// using variant of single-word Wang/Jenkins hash.
// TODO(kevinb): use Hashing/move this to Hashing?
h += (h << 15) ^ 0xffffcd7d;
h ^= (h >>> 10);
h += (h << 3);
h ^= (h >>> 6);
h += (h << 2) + (h << 14);
return h ^ (h >>> 16);
}
/**
* This method is a convenience for testing. Code should call {@link Segment#newEntry} directly.
*/
@GuardedBy("Segment.this")
@VisibleForTesting
ReferenceEntry<K, V> newEntry(K key, int hash, @Nullable ReferenceEntry<K, V> next) {
return segmentFor(hash).newEntry(key, hash, next);
}
/**
* This method is a convenience for testing. Code should call {@link Segment#copyEntry} directly.
*/
@GuardedBy("Segment.this")
@VisibleForTesting
ReferenceEntry<K, V> copyEntry(ReferenceEntry<K, V> original, ReferenceEntry<K, V> newNext) {
int hash = original.getHash();
return segmentFor(hash).copyEntry(original, newNext);
}
/**
* This method is a convenience for testing. Code should call {@link Segment#setValue} instead.
*/
@GuardedBy("Segment.this")
@VisibleForTesting
ValueReference<K, V> newValueReference(ReferenceEntry<K, V> entry, V value) {
int hash = entry.getHash();
return valueStrength.referenceValue(segmentFor(hash), entry, value);
}
int hash(Object key) {
int h = keyEquivalence.hash(key);
return rehash(h);
}
void reclaimValue(ValueReference<K, V> valueReference) {
ReferenceEntry<K, V> entry = valueReference.getEntry();
int hash = entry.getHash();
segmentFor(hash).reclaimValue(entry.getKey(), hash, valueReference);
}
void reclaimKey(ReferenceEntry<K, V> entry) {
int hash = entry.getHash();
segmentFor(hash).reclaimKey(entry, hash);
}
/**
* This method is a convenience for testing. Code should call {@link Segment#getLiveValue}
* instead.
*/
@VisibleForTesting
boolean isLive(ReferenceEntry<K, V> entry) {
return segmentFor(entry.getHash()).getLiveValue(entry) != null;
}
/**
* Returns the segment that should be used for a key with the given hash.
*
* @param hash the hash code for the key
* @return the segment
*/
Segment<K, V> segmentFor(int hash) {
// TODO(fry): Lazily create segments?
return segments[(hash >>> segmentShift) & segmentMask];
}
Segment<K, V> createSegment(int initialCapacity, int maxSegmentSize) {
return new Segment<K, V>(this, initialCapacity, maxSegmentSize);
}
/**
* Gets the value from an entry. Returns {@code null} if the entry is invalid,
* partially-collected, computing, or expired. Unlike {@link Segment#getLiveValue} this method
* does not attempt to clean up stale entries.
*/
V getLiveValue(ReferenceEntry<K, V> entry) {
if (entry.getKey() == null) {
return null;
}
V value = entry.getValueReference().get();
if (value == null) {
return null;
}
if (expires() && isExpired(entry)) {
return null;
}
return value;
}
// expiration
/**
* Returns {@code true} if the entry has expired.
*/
boolean isExpired(ReferenceEntry<K, V> entry) {
return isExpired(entry, ticker.read());
}
/**
* Returns {@code true} if the entry has expired.
*/
boolean isExpired(ReferenceEntry<K, V> entry, long now) {
// if the expiration time had overflowed, this "undoes" the overflow
return now - entry.getExpirationTime() > 0;
}
@GuardedBy("Segment.this")
static <K, V> void connectExpirables(ReferenceEntry<K, V> previous, ReferenceEntry<K, V> next) {
previous.setNextExpirable(next);
next.setPreviousExpirable(previous);
}
@GuardedBy("Segment.this")
static <K, V> void nullifyExpirable(ReferenceEntry<K, V> nulled) {
ReferenceEntry<K, V> nullEntry = nullEntry();
nulled.setNextExpirable(nullEntry);
nulled.setPreviousExpirable(nullEntry);
}
// eviction
/**
* Notifies listeners that an entry has been automatically removed due to expiration, eviction,
* or eligibility for garbage collection. This should be called every time expireEntries or
* evictEntry is called (once the lock is released).
*/
void processPendingNotifications() {
RemovalNotification<K, V> notification;
while ((notification = removalNotificationQueue.poll()) != null) {
try {
removalListener.onRemoval(notification);
} catch (Exception e) {
logger.log(Level.WARNING, "Exception thrown by removal listener", e);
}
}
}
/** Links the evitables together. */
@GuardedBy("Segment.this")
static <K, V> void connectEvictables(ReferenceEntry<K, V> previous, ReferenceEntry<K, V> next) {
previous.setNextEvictable(next);
next.setPreviousEvictable(previous);
}
@GuardedBy("Segment.this")
static <K, V> void nullifyEvictable(ReferenceEntry<K, V> nulled) {
ReferenceEntry<K, V> nullEntry = nullEntry();
nulled.setNextEvictable(nullEntry);
nulled.setPreviousEvictable(nullEntry);
}
@SuppressWarnings("unchecked")
final Segment<K, V>[] newSegmentArray(int ssize) {
return new Segment[ssize];
}
// Inner Classes
/**
* Segments are specialized versions of hash tables. This subclass inherits from ReentrantLock
* opportunistically, just to simplify some locking and avoid separate construction.
*/
@SuppressWarnings("serial") // This class is never serialized.
static class Segment<K, V> extends ReentrantLock {
/*
* TODO(fry): Consider copying variables (like evictsBySize) from outer class into this class.
* It will require more memory but will reduce indirection.
*/
/*
* Segments maintain a table of entry lists that are ALWAYS kept in a consistent state, so can
* be read without locking. Next fields of nodes are immutable (final). All list additions are
* performed at the front of each bin. This makes it easy to check changes, and also fast to
* traverse. When nodes would otherwise be changed, new nodes are created to replace them. This
* works well for hash tables since the bin lists tend to be short. (The average length is less
* than two.)
*
* Read operations can thus proceed without locking, but rely on selected uses of volatiles to
* ensure that completed write operations performed by other threads are noticed. For most
* purposes, the "count" field, tracking the number of elements, serves as that volatile
* variable ensuring visibility. This is convenient because this field needs to be read in many
* read operations anyway:
*
* - All (unsynchronized) read operations must first read the "count" field, and should not
* look at table entries if it is 0.
*
* - All (synchronized) write operations should write to the "count" field after structurally
* changing any bin. The operations must not take any action that could even momentarily
* cause a concurrent read operation to see inconsistent data. This is made easier by the
* nature of the read operations in Map. For example, no operation can reveal that the table
* has grown but the threshold has not yet been updated, so there are no atomicity requirements
* for this with respect to reads.
*
* As a guide, all critical volatile reads and writes to the count field are marked in code
* comments.
*/
final MapMakerInternalMap<K, V> map;
/**
* The number of live elements in this segment's region. This does not include unset elements
* which are awaiting cleanup.
*/
volatile int count;
/**
* Number of updates that alter the size of the table. This is used during bulk-read methods to
* make sure they see a consistent snapshot: If modCounts change during a traversal of segments
* computing size or checking containsValue, then we might have an inconsistent view of state
* so (usually) must retry.
*/
int modCount;
/**
* The table is expanded when its size exceeds this threshold. (The value of this field is
* always {@code (int)(capacity * 0.75)}.)
*/
int threshold;
/**
* The per-segment table.
*/
volatile AtomicReferenceArray<ReferenceEntry<K, V>> table;
/**
* The maximum size of this map. MapMaker.UNSET_INT if there is no maximum.
*/
final int maxSegmentSize;
/**
* The key reference queue contains entries whose keys have been garbage collected, and which
* need to be cleaned up internally.
*/
final ReferenceQueue<K> keyReferenceQueue;
/**
* The value reference queue contains value references whose values have been garbage collected,
* and which need to be cleaned up internally.
*/
final ReferenceQueue<V> valueReferenceQueue;
/**
* The recency queue is used to record which entries were accessed for updating the eviction
* list's ordering. It is drained as a batch operation when either the DRAIN_THRESHOLD is
* crossed or a write occurs on the segment.
*/
final Queue<ReferenceEntry<K, V>> recencyQueue;
/**
* A counter of the number of reads since the last write, used to drain queues on a small
* fraction of read operations.
*/
final AtomicInteger readCount = new AtomicInteger();
/**
* A queue of elements currently in the map, ordered by access time. Elements are added to the
* tail of the queue on access/write.
*/
@GuardedBy("Segment.this")
final Queue<ReferenceEntry<K, V>> evictionQueue;
/**
* A queue of elements currently in the map, ordered by expiration time (either access or write
* time). Elements are added to the tail of the queue on access/write.
*/
@GuardedBy("Segment.this")
final Queue<ReferenceEntry<K, V>> expirationQueue;
Segment(MapMakerInternalMap<K, V> map, int initialCapacity, int maxSegmentSize) {
this.map = map;
this.maxSegmentSize = maxSegmentSize;
initTable(newEntryArray(initialCapacity));
keyReferenceQueue = map.usesKeyReferences()
? new ReferenceQueue<K>() : null;
valueReferenceQueue = map.usesValueReferences()
? new ReferenceQueue<V>() : null;
recencyQueue = (map.evictsBySize() || map.expiresAfterAccess())
? new ConcurrentLinkedQueue<ReferenceEntry<K, V>>()
: MapMakerInternalMap.<ReferenceEntry<K, V>>discardingQueue();
evictionQueue = map.evictsBySize()
? new EvictionQueue<K, V>()
: MapMakerInternalMap.<ReferenceEntry<K, V>>discardingQueue();
expirationQueue = map.expires()
? new ExpirationQueue<K, V>()
: MapMakerInternalMap.<ReferenceEntry<K, V>>discardingQueue();
}
AtomicReferenceArray<ReferenceEntry<K, V>> newEntryArray(int size) {
return new AtomicReferenceArray<ReferenceEntry<K, V>>(size);
}
void initTable(AtomicReferenceArray<ReferenceEntry<K, V>> newTable) {
this.threshold = newTable.length() * 3 / 4; // 0.75
if (this.threshold == maxSegmentSize) {
// prevent spurious expansion before eviction
this.threshold++;
}
this.table = newTable;
}
@GuardedBy("Segment.this")
ReferenceEntry<K, V> newEntry(K key, int hash, @Nullable ReferenceEntry<K, V> next) {
return map.entryFactory.newEntry(this, key, hash, next);
}
@GuardedBy("Segment.this")
ReferenceEntry<K, V> copyEntry(ReferenceEntry<K, V> original, ReferenceEntry<K, V> newNext) {
ValueReference<K, V> valueReference = original.getValueReference();
ReferenceEntry<K, V> newEntry = map.entryFactory.copyEntry(this, original, newNext);
newEntry.setValueReference(valueReference.copyFor(this.valueReferenceQueue, newEntry));
return newEntry;
}
/**
* Sets a new value of an entry. Adds newly created entries at the end of the expiration queue.
*/
@GuardedBy("Segment.this")
void setValue(ReferenceEntry<K, V> entry, V value) {
ValueReference<K, V> valueReference = map.valueStrength.referenceValue(this, entry, value);
entry.setValueReference(valueReference);
recordWrite(entry);
}
// reference queues, for garbage collection cleanup
/**
* Cleanup collected entries when the lock is available.
*/
void tryDrainReferenceQueues() {
if (tryLock()) {
try {
drainReferenceQueues();
} finally {
unlock();
}
}
}
/**
* Drain the key and value reference queues, cleaning up internal entries containing garbage
* collected keys or values.
*/
@GuardedBy("Segment.this")
void drainReferenceQueues() {
if (map.usesKeyReferences()) {
drainKeyReferenceQueue();
}
if (map.usesValueReferences()) {
drainValueReferenceQueue();
}
}
@GuardedBy("Segment.this")
void drainKeyReferenceQueue() {
Reference<? extends K> ref;
int i = 0;
while ((ref = keyReferenceQueue.poll()) != null) {
@SuppressWarnings("unchecked")
ReferenceEntry<K, V> entry = (ReferenceEntry<K, V>) ref;
map.reclaimKey(entry);
if (++i == DRAIN_MAX) {
break;
}
}
}
@GuardedBy("Segment.this")
void drainValueReferenceQueue() {
Reference<? extends V> ref;
int i = 0;
while ((ref = valueReferenceQueue.poll()) != null) {
@SuppressWarnings("unchecked")
ValueReference<K, V> valueReference = (ValueReference<K, V>) ref;
map.reclaimValue(valueReference);
if (++i == DRAIN_MAX) {
break;
}
}
}
/**
* Clears all entries from the key and value reference queues.
*/
void clearReferenceQueues() {
if (map.usesKeyReferences()) {
clearKeyReferenceQueue();
}
if (map.usesValueReferences()) {
clearValueReferenceQueue();
}
}
void clearKeyReferenceQueue() {
while (keyReferenceQueue.poll() != null) {}
}
void clearValueReferenceQueue() {
while (valueReferenceQueue.poll() != null) {}
}
// recency queue, shared by expiration and eviction
/**
* Records the relative order in which this read was performed by adding {@code entry} to the
* recency queue. At write-time, or when the queue is full past the threshold, the queue will
* be drained and the entries therein processed.
*
* <p>Note: locked reads should use {@link #recordLockedRead}.
*/
void recordRead(ReferenceEntry<K, V> entry) {
if (map.expiresAfterAccess()) {
recordExpirationTime(entry, map.expireAfterAccessNanos);
}
recencyQueue.add(entry);
}
/**
* Updates the eviction metadata that {@code entry} was just read. This currently amounts to
* adding {@code entry} to relevant eviction lists.
*
* <p>Note: this method should only be called under lock, as it directly manipulates the
* eviction queues. Unlocked reads should use {@link #recordRead}.
*/
@GuardedBy("Segment.this")
void recordLockedRead(ReferenceEntry<K, V> entry) {
evictionQueue.add(entry);
if (map.expiresAfterAccess()) {
recordExpirationTime(entry, map.expireAfterAccessNanos);
expirationQueue.add(entry);
}
}
/**
* Updates eviction metadata that {@code entry} was just written. This currently amounts to
* adding {@code entry} to relevant eviction lists.
*/
@GuardedBy("Segment.this")
void recordWrite(ReferenceEntry<K, V> entry) {
// we are already under lock, so drain the recency queue immediately
drainRecencyQueue();
evictionQueue.add(entry);
if (map.expires()) {
// currently MapMaker ensures that expireAfterWrite and
// expireAfterAccess are mutually exclusive
long expiration = map.expiresAfterAccess()
? map.expireAfterAccessNanos
: map.expireAfterWriteNanos;
recordExpirationTime(entry, expiration);
expirationQueue.add(entry);
}
}
/**
* Drains the recency queue, updating eviction metadata that the entries therein were read in
* the specified relative order. This currently amounts to adding them to relevant eviction
* lists (accounting for the fact that they could have been removed from the map since being
* added to the recency queue).
*/
@GuardedBy("Segment.this")
void drainRecencyQueue() {
ReferenceEntry<K, V> e;
while ((e = recencyQueue.poll()) != null) {
// An entry may be in the recency queue despite it being removed from
// the map . This can occur when the entry was concurrently read while a
// writer is removing it from the segment or after a clear has removed
// all of the segment's entries.
if (evictionQueue.contains(e)) {
evictionQueue.add(e);
}
if (map.expiresAfterAccess() && expirationQueue.contains(e)) {
expirationQueue.add(e);
}
}
}
// expiration
void recordExpirationTime(ReferenceEntry<K, V> entry, long expirationNanos) {
// might overflow, but that's okay (see isExpired())
entry.setExpirationTime(map.ticker.read() + expirationNanos);
}
/**
* Cleanup expired entries when the lock is available.
*/
void tryExpireEntries() {
if (tryLock()) {
try {
expireEntries();
} finally {
unlock();
// don't call postWriteCleanup as we're in a read
}
}
}
@GuardedBy("Segment.this")
void expireEntries() {
drainRecencyQueue();
if (expirationQueue.isEmpty()) {
// There's no point in calling nanoTime() if we have no entries to
// expire.
return;
}
long now = map.ticker.read();
ReferenceEntry<K, V> e;
while ((e = expirationQueue.peek()) != null && map.isExpired(e, now)) {
if (!removeEntry(e, e.getHash(), RemovalCause.EXPIRED)) {
throw new AssertionError();
}
}
}
// eviction
void enqueueNotification(ReferenceEntry<K, V> entry, RemovalCause cause) {
enqueueNotification(entry.getKey(), entry.getHash(), entry.getValueReference().get(), cause);
}
void enqueueNotification(@Nullable K key, int hash, @Nullable V value, RemovalCause cause) {
if (map.removalNotificationQueue != DISCARDING_QUEUE) {
RemovalNotification<K, V> notification = new RemovalNotification<K, V>(key, value, cause);
map.removalNotificationQueue.offer(notification);
}
}
/**
* Performs eviction if the segment is full. This should only be called prior to adding a new
* entry and increasing {@code count}.
*
* @return {@code true} if eviction occurred
*/
@GuardedBy("Segment.this")
boolean evictEntries() {
if (map.evictsBySize() && count >= maxSegmentSize) {
drainRecencyQueue();
ReferenceEntry<K, V> e = evictionQueue.remove();
if (!removeEntry(e, e.getHash(), RemovalCause.SIZE)) {
throw new AssertionError();
}
return true;
}
return false;
}
/**
* Returns first entry of bin for given hash.
*/
ReferenceEntry<K, V> getFirst(int hash) {
// read this volatile field only once
AtomicReferenceArray<ReferenceEntry<K, V>> table = this.table;
return table.get(hash & (table.length() - 1));
}
// Specialized implementations of map methods
ReferenceEntry<K, V> getEntry(Object key, int hash) {
if (count != 0) { // read-volatile
for (ReferenceEntry<K, V> e = getFirst(hash); e != null; e = e.getNext()) {
if (e.getHash() != hash) {
continue;
}
K entryKey = e.getKey();
if (entryKey == null) {
tryDrainReferenceQueues();
continue;
}
if (map.keyEquivalence.equivalent(key, entryKey)) {
return e;
}
}
}
return null;
}
ReferenceEntry<K, V> getLiveEntry(Object key, int hash) {
ReferenceEntry<K, V> e = getEntry(key, hash);
if (e == null) {
return null;
} else if (map.expires() && map.isExpired(e)) {
tryExpireEntries();
return null;
}
return e;
}
V get(Object key, int hash) {
try {
ReferenceEntry<K, V> e = getLiveEntry(key, hash);
if (e == null) {
return null;
}
V value = e.getValueReference().get();
if (value != null) {
recordRead(e);
} else {
tryDrainReferenceQueues();
}
return value;
} finally {
postReadCleanup();
}
}
boolean containsKey(Object key, int hash) {
try {
if (count != 0) { // read-volatile
ReferenceEntry<K, V> e = getLiveEntry(key, hash);
if (e == null) {
return false;
}
return e.getValueReference().get() != null;
}
return false;
} finally {
postReadCleanup();
}
}
/**
* This method is a convenience for testing. Code should call {@link
* MapMakerInternalMap#containsValue} directly.
*/
@VisibleForTesting
boolean containsValue(Object value) {
try {
if (count != 0) { // read-volatile
AtomicReferenceArray<ReferenceEntry<K, V>> table = this.table;
int length = table.length();
for (int i = 0; i < length; ++i) {
for (ReferenceEntry<K, V> e = table.get(i); e != null; e = e.getNext()) {
V entryValue = getLiveValue(e);
if (entryValue == null) {
continue;
}
if (map.valueEquivalence.equivalent(value, entryValue)) {
return true;
}
}
}
}
return false;
} finally {
postReadCleanup();
}
}
V put(K key, int hash, V value, boolean onlyIfAbsent) {
lock();
try {
preWriteCleanup();
int newCount = this.count + 1;
if (newCount > this.threshold) { // ensure capacity
expand();
newCount = this.count + 1;
}
AtomicReferenceArray<ReferenceEntry<K, V>> table = this.table;
int index = hash & (table.length() - 1);
ReferenceEntry<K, V> first = table.get(index);
// Look for an existing entry.
for (ReferenceEntry<K, V> e = first; e != null; e = e.getNext()) {
K entryKey = e.getKey();
if (e.getHash() == hash && entryKey != null
&& map.keyEquivalence.equivalent(key, entryKey)) {
// We found an existing entry.
ValueReference<K, V> valueReference = e.getValueReference();
V entryValue = valueReference.get();
if (entryValue == null) {
++modCount;
setValue(e, value);
if (!valueReference.isComputingReference()) {
enqueueNotification(key, hash, entryValue, RemovalCause.COLLECTED);
newCount = this.count; // count remains unchanged
} else if (evictEntries()) { // evictEntries after setting new value
newCount = this.count + 1;
}
this.count = newCount; // write-volatile
return null;
} else if (onlyIfAbsent) {
// Mimic
// "if (!map.containsKey(key)) ...
// else return map.get(key);
recordLockedRead(e);
return entryValue;
} else {
// clobber existing entry, count remains unchanged
++modCount;
enqueueNotification(key, hash, entryValue, RemovalCause.REPLACED);
setValue(e, value);
return entryValue;
}
}
}
// Create a new entry.
++modCount;
ReferenceEntry<K, V> newEntry = newEntry(key, hash, first);
setValue(newEntry, value);
table.set(index, newEntry);
if (evictEntries()) { // evictEntries after setting new value
newCount = this.count + 1;
}
this.count = newCount; // write-volatile
return null;
} finally {
unlock();
postWriteCleanup();
}
}
/**
* Expands the table if possible.
*/
@GuardedBy("Segment.this")
void expand() {
AtomicReferenceArray<ReferenceEntry<K, V>> oldTable = table;
int oldCapacity = oldTable.length();
if (oldCapacity >= MAXIMUM_CAPACITY) {
return;
}
/*
* Reclassify nodes in each list to new Map. Because we are using power-of-two expansion, the
* elements from each bin must either stay at same index, or move with a power of two offset.
* We eliminate unnecessary node creation by catching cases where old nodes can be reused
* because their next fields won't change. Statistically, at the default threshold, only
* about one-sixth of them need cloning when a table doubles. The nodes they replace will be
* garbage collectable as soon as they are no longer referenced by any reader thread that may
* be in the midst of traversing table right now.
*/
int newCount = count;
AtomicReferenceArray<ReferenceEntry<K, V>> newTable = newEntryArray(oldCapacity << 1);
threshold = newTable.length() * 3 / 4;
int newMask = newTable.length() - 1;
for (int oldIndex = 0; oldIndex < oldCapacity; ++oldIndex) {
// We need to guarantee that any existing reads of old Map can
// proceed. So we cannot yet null out each bin.
ReferenceEntry<K, V> head = oldTable.get(oldIndex);
if (head != null) {
ReferenceEntry<K, V> next = head.getNext();
int headIndex = head.getHash() & newMask;
// Single node on list
if (next == null) {
newTable.set(headIndex, head);
} else {
// Reuse the consecutive sequence of nodes with the same target
// index from the end of the list. tail points to the first
// entry in the reusable list.
ReferenceEntry<K, V> tail = head;
int tailIndex = headIndex;
for (ReferenceEntry<K, V> e = next; e != null; e = e.getNext()) {
int newIndex = e.getHash() & newMask;
if (newIndex != tailIndex) {
// The index changed. We'll need to copy the previous entry.
tailIndex = newIndex;
tail = e;
}
}
newTable.set(tailIndex, tail);
// Clone nodes leading up to the tail.
for (ReferenceEntry<K, V> e = head; e != tail; e = e.getNext()) {
if (isCollected(e)) {
removeCollectedEntry(e);
newCount--;
} else {
int newIndex = e.getHash() & newMask;
ReferenceEntry<K, V> newNext = newTable.get(newIndex);
ReferenceEntry<K, V> newFirst = copyEntry(e, newNext);
newTable.set(newIndex, newFirst);
}
}
}
}
}
table = newTable;
this.count = newCount;
}
boolean replace(K key, int hash, V oldValue, V newValue) {
lock();
try {
preWriteCleanup();
AtomicReferenceArray<ReferenceEntry<K, V>> table = this.table;
int index = hash & (table.length() - 1);
ReferenceEntry<K, V> first = table.get(index);
for (ReferenceEntry<K, V> e = first; e != null; e = e.getNext()) {
K entryKey = e.getKey();
if (e.getHash() == hash && entryKey != null
&& map.keyEquivalence.equivalent(key, entryKey)) {
// If the value disappeared, this entry is partially collected,
// and we should pretend like it doesn't exist.
ValueReference<K, V> valueReference = e.getValueReference();
V entryValue = valueReference.get();
if (entryValue == null) {
if (isCollected(valueReference)) {
int newCount = this.count - 1;
++modCount;
enqueueNotification(entryKey, hash, entryValue, RemovalCause.COLLECTED);
ReferenceEntry<K, V> newFirst = removeFromChain(first, e);
newCount = this.count - 1;
table.set(index, newFirst);
this.count = newCount; // write-volatile
}
return false;
}
if (map.valueEquivalence.equivalent(oldValue, entryValue)) {
++modCount;
enqueueNotification(key, hash, entryValue, RemovalCause.REPLACED);
setValue(e, newValue);
return true;
} else {
// Mimic
// "if (map.containsKey(key) && map.get(key).equals(oldValue))..."
recordLockedRead(e);
return false;
}
}
}
return false;
} finally {
unlock();
postWriteCleanup();
}
}
V replace(K key, int hash, V newValue) {
lock();
try {
preWriteCleanup();
AtomicReferenceArray<ReferenceEntry<K, V>> table = this.table;
int index = hash & (table.length() - 1);
ReferenceEntry<K, V> first = table.get(index);
for (ReferenceEntry<K, V> e = first; e != null; e = e.getNext()) {
K entryKey = e.getKey();
if (e.getHash() == hash && entryKey != null
&& map.keyEquivalence.equivalent(key, entryKey)) {
// If the value disappeared, this entry is partially collected,
// and we should pretend like it doesn't exist.
ValueReference<K, V> valueReference = e.getValueReference();
V entryValue = valueReference.get();
if (entryValue == null) {
if (isCollected(valueReference)) {
int newCount = this.count - 1;
++modCount;
enqueueNotification(entryKey, hash, entryValue, RemovalCause.COLLECTED);
ReferenceEntry<K, V> newFirst = removeFromChain(first, e);
newCount = this.count - 1;
table.set(index, newFirst);
this.count = newCount; // write-volatile
}
return null;
}
++modCount;
enqueueNotification(key, hash, entryValue, RemovalCause.REPLACED);
setValue(e, newValue);
return entryValue;
}
}
return null;
} finally {
unlock();
postWriteCleanup();
}
}
V remove(Object key, int hash) {
lock();
try {
preWriteCleanup();
int newCount = this.count - 1;
AtomicReferenceArray<ReferenceEntry<K, V>> table = this.table;
int index = hash & (table.length() - 1);
ReferenceEntry<K, V> first = table.get(index);
for (ReferenceEntry<K, V> e = first; e != null; e = e.getNext()) {
K entryKey = e.getKey();
if (e.getHash() == hash && entryKey != null
&& map.keyEquivalence.equivalent(key, entryKey)) {
ValueReference<K, V> valueReference = e.getValueReference();
V entryValue = valueReference.get();
RemovalCause cause;
if (entryValue != null) {
cause = RemovalCause.EXPLICIT;
} else if (isCollected(valueReference)) {
cause = RemovalCause.COLLECTED;
} else {
return null;
}
++modCount;
enqueueNotification(entryKey, hash, entryValue, cause);
ReferenceEntry<K, V> newFirst = removeFromChain(first, e);
newCount = this.count - 1;
table.set(index, newFirst);
this.count = newCount; // write-volatile
return entryValue;
}
}
return null;
} finally {
unlock();
postWriteCleanup();
}
}
boolean remove(Object key, int hash, Object value) {
lock();
try {
preWriteCleanup();
int newCount = this.count - 1;
AtomicReferenceArray<ReferenceEntry<K, V>> table = this.table;
int index = hash & (table.length() - 1);
ReferenceEntry<K, V> first = table.get(index);
for (ReferenceEntry<K, V> e = first; e != null; e = e.getNext()) {
K entryKey = e.getKey();
if (e.getHash() == hash && entryKey != null
&& map.keyEquivalence.equivalent(key, entryKey)) {
ValueReference<K, V> valueReference = e.getValueReference();
V entryValue = valueReference.get();
RemovalCause cause;
if (map.valueEquivalence.equivalent(value, entryValue)) {
cause = RemovalCause.EXPLICIT;
} else if (isCollected(valueReference)) {
cause = RemovalCause.COLLECTED;
} else {
return false;
}
++modCount;
enqueueNotification(entryKey, hash, entryValue, cause);
ReferenceEntry<K, V> newFirst = removeFromChain(first, e);
newCount = this.count - 1;
table.set(index, newFirst);
this.count = newCount; // write-volatile
return (cause == RemovalCause.EXPLICIT);
}
}
return false;
} finally {
unlock();
postWriteCleanup();
}
}
void clear() {
if (count != 0) {
lock();
try {
AtomicReferenceArray<ReferenceEntry<K, V>> table = this.table;
if (map.removalNotificationQueue != DISCARDING_QUEUE) {
for (int i = 0; i < table.length(); ++i) {
for (ReferenceEntry<K, V> e = table.get(i); e != null; e = e.getNext()) {
// Computing references aren't actually in the map yet.
if (!e.getValueReference().isComputingReference()) {
enqueueNotification(e, RemovalCause.EXPLICIT);
}
}
}
}
for (int i = 0; i < table.length(); ++i) {
table.set(i, null);
}
clearReferenceQueues();
evictionQueue.clear();
expirationQueue.clear();
readCount.set(0);
++modCount;
count = 0; // write-volatile
} finally {
unlock();
postWriteCleanup();
}
}
}
/**
* Removes an entry from within a table. All entries following the removed node can stay, but
* all preceding ones need to be cloned.
*
* <p>This method does not decrement count for the removed entry, but does decrement count for
* all partially collected entries which are skipped. As such callers which are modifying count
* must re-read it after calling removeFromChain.
*
* @param first the first entry of the table
* @param entry the entry being removed from the table
* @return the new first entry for the table
*/
@GuardedBy("Segment.this")
ReferenceEntry<K, V> removeFromChain(ReferenceEntry<K, V> first, ReferenceEntry<K, V> entry) {
evictionQueue.remove(entry);
expirationQueue.remove(entry);
int newCount = count;
ReferenceEntry<K, V> newFirst = entry.getNext();
for (ReferenceEntry<K, V> e = first; e != entry; e = e.getNext()) {
if (isCollected(e)) {
removeCollectedEntry(e);
newCount--;
} else {
newFirst = copyEntry(e, newFirst);
}
}
this.count = newCount;
return newFirst;
}
void removeCollectedEntry(ReferenceEntry<K, V> entry) {
enqueueNotification(entry, RemovalCause.COLLECTED);
evictionQueue.remove(entry);
expirationQueue.remove(entry);
}
/**
* Removes an entry whose key has been garbage collected.
*/
boolean reclaimKey(ReferenceEntry<K, V> entry, int hash) {
lock();
try {
int newCount = count - 1;
AtomicReferenceArray<ReferenceEntry<K, V>> table = this.table;
int index = hash & (table.length() - 1);
ReferenceEntry<K, V> first = table.get(index);
for (ReferenceEntry<K, V> e = first; e != null; e = e.getNext()) {
if (e == entry) {
++modCount;
enqueueNotification(
e.getKey(), hash, e.getValueReference().get(), RemovalCause.COLLECTED);
ReferenceEntry<K, V> newFirst = removeFromChain(first, e);
newCount = this.count - 1;
table.set(index, newFirst);
this.count = newCount; // write-volatile
return true;
}
}
return false;
} finally {
unlock();
postWriteCleanup();
}
}
/**
* Removes an entry whose value has been garbage collected.
*/
boolean reclaimValue(K key, int hash, ValueReference<K, V> valueReference) {
lock();
try {
int newCount = this.count - 1;
AtomicReferenceArray<ReferenceEntry<K, V>> table = this.table;
int index = hash & (table.length() - 1);
ReferenceEntry<K, V> first = table.get(index);
for (ReferenceEntry<K, V> e = first; e != null; e = e.getNext()) {
K entryKey = e.getKey();
if (e.getHash() == hash && entryKey != null
&& map.keyEquivalence.equivalent(key, entryKey)) {
ValueReference<K, V> v = e.getValueReference();
if (v == valueReference) {
++modCount;
enqueueNotification(key, hash, valueReference.get(), RemovalCause.COLLECTED);
ReferenceEntry<K, V> newFirst = removeFromChain(first, e);
newCount = this.count - 1;
table.set(index, newFirst);
this.count = newCount; // write-volatile
return true;
}
return false;
}
}
return false;
} finally {
unlock();
if (!isHeldByCurrentThread()) { // don't cleanup inside of put
postWriteCleanup();
}
}
}
/**
* Clears a value that has not yet been set, and thus does not require count to be modified.
*/
boolean clearValue(K key, int hash, ValueReference<K, V> valueReference) {
lock();
try {
AtomicReferenceArray<ReferenceEntry<K, V>> table = this.table;
int index = hash & (table.length() - 1);
ReferenceEntry<K, V> first = table.get(index);
for (ReferenceEntry<K, V> e = first; e != null; e = e.getNext()) {
K entryKey = e.getKey();
if (e.getHash() == hash && entryKey != null
&& map.keyEquivalence.equivalent(key, entryKey)) {
ValueReference<K, V> v = e.getValueReference();
if (v == valueReference) {
ReferenceEntry<K, V> newFirst = removeFromChain(first, e);
table.set(index, newFirst);
return true;
}
return false;
}
}
return false;
} finally {
unlock();
postWriteCleanup();
}
}
@GuardedBy("Segment.this")
boolean removeEntry(ReferenceEntry<K, V> entry, int hash, RemovalCause cause) {
int newCount = this.count - 1;
AtomicReferenceArray<ReferenceEntry<K, V>> table = this.table;
int index = hash & (table.length() - 1);
ReferenceEntry<K, V> first = table.get(index);
for (ReferenceEntry<K, V> e = first; e != null; e = e.getNext()) {
if (e == entry) {
++modCount;
enqueueNotification(e.getKey(), hash, e.getValueReference().get(), cause);
ReferenceEntry<K, V> newFirst = removeFromChain(first, e);
newCount = this.count - 1;
table.set(index, newFirst);
this.count = newCount; // write-volatile
return true;
}
}
return false;
}
/**
* Returns {@code true} if the entry has been partially collected, meaning that either the key
* is null, or the value is null and it is not computing.
*/
boolean isCollected(ReferenceEntry<K, V> entry) {
if (entry.getKey() == null) {
return true;
}
return isCollected(entry.getValueReference());
}
/**
* Returns {@code true} if the value has been partially collected, meaning that the value is
* null and it is not computing.
*/
boolean isCollected(ValueReference<K, V> valueReference) {
if (valueReference.isComputingReference()) {
return false;
}
return (valueReference.get() == null);
}
/**
* Gets the value from an entry. Returns {@code null} if the entry is invalid,
* partially-collected, computing, or expired.
*/
V getLiveValue(ReferenceEntry<K, V> entry) {
if (entry.getKey() == null) {
tryDrainReferenceQueues();
return null;
}
V value = entry.getValueReference().get();
if (value == null) {
tryDrainReferenceQueues();
return null;
}
if (map.expires() && map.isExpired(entry)) {
tryExpireEntries();
return null;
}
return value;
}
/**
* Performs routine cleanup following a read. Normally cleanup happens during writes, or from
* the cleanupExecutor. If cleanup is not observed after a sufficient number of reads, try
* cleaning up from the read thread.
*/
void postReadCleanup() {
if ((readCount.incrementAndGet() & DRAIN_THRESHOLD) == 0) {
runCleanup();
}
}
/**
* Performs routine cleanup prior to executing a write. This should be called every time a
* write thread acquires the segment lock, immediately after acquiring the lock.
*
* <p>Post-condition: expireEntries has been run.
*/
@GuardedBy("Segment.this")
void preWriteCleanup() {
runLockedCleanup();
}
/**
* Performs routine cleanup following a write.
*/
void postWriteCleanup() {
runUnlockedCleanup();
}
void runCleanup() {
runLockedCleanup();
runUnlockedCleanup();
}
void runLockedCleanup() {
if (tryLock()) {
try {
drainReferenceQueues();
expireEntries(); // calls drainRecencyQueue
readCount.set(0);
} finally {
unlock();
}
}
}
void runUnlockedCleanup() {
// locked cleanup may generate notifications we can send unlocked
if (!isHeldByCurrentThread()) {
map.processPendingNotifications();
}
}
}
// Queues
/**
* A custom queue for managing eviction order. Note that this is tightly integrated with {@code
* ReferenceEntry}, upon which it relies to perform its linking.
*
* <p>Note that this entire implementation makes the assumption that all elements which are in
* the map are also in this queue, and that all elements not in the queue are not in the map.
*
* <p>The benefits of creating our own queue are that (1) we can replace elements in the middle
* of the queue as part of copyEvictableEntry, and (2) the contains method is highly optimized
* for the current model.
*/
static final class EvictionQueue<K, V> extends AbstractQueue<ReferenceEntry<K, V>> {
final ReferenceEntry<K, V> head = new AbstractReferenceEntry<K, V>() {
ReferenceEntry<K, V> nextEvictable = this;
@Override
public ReferenceEntry<K, V> getNextEvictable() {
return nextEvictable;
}
@Override
public void setNextEvictable(ReferenceEntry<K, V> next) {
this.nextEvictable = next;
}
ReferenceEntry<K, V> previousEvictable = this;
@Override
public ReferenceEntry<K, V> getPreviousEvictable() {
return previousEvictable;
}
@Override
public void setPreviousEvictable(ReferenceEntry<K, V> previous) {
this.previousEvictable = previous;
}
};
// implements Queue
@Override
public boolean offer(ReferenceEntry<K, V> entry) {
// unlink
connectEvictables(entry.getPreviousEvictable(), entry.getNextEvictable());
// add to tail
connectEvictables(head.getPreviousEvictable(), entry);
connectEvictables(entry, head);
return true;
}
@Override
public ReferenceEntry<K, V> peek() {
ReferenceEntry<K, V> next = head.getNextEvictable();
return (next == head) ? null : next;
}
@Override
public ReferenceEntry<K, V> poll() {
ReferenceEntry<K, V> next = head.getNextEvictable();
if (next == head) {
return null;
}
remove(next);
return next;
}
@Override
@SuppressWarnings("unchecked")
public boolean remove(Object o) {
ReferenceEntry<K, V> e = (ReferenceEntry) o;
ReferenceEntry<K, V> previous = e.getPreviousEvictable();
ReferenceEntry<K, V> next = e.getNextEvictable();
connectEvictables(previous, next);
nullifyEvictable(e);
return next != NullEntry.INSTANCE;
}
@Override
@SuppressWarnings("unchecked")
public boolean contains(Object o) {
ReferenceEntry<K, V> e = (ReferenceEntry) o;
return e.getNextEvictable() != NullEntry.INSTANCE;
}
@Override
public boolean isEmpty() {
return head.getNextEvictable() == head;
}
@Override
public int size() {
int size = 0;
for (ReferenceEntry<K, V> e = head.getNextEvictable(); e != head; e = e.getNextEvictable()) {
size++;
}
return size;
}
@Override
public void clear() {
ReferenceEntry<K, V> e = head.getNextEvictable();
while (e != head) {
ReferenceEntry<K, V> next = e.getNextEvictable();
nullifyEvictable(e);
e = next;
}
head.setNextEvictable(head);
head.setPreviousEvictable(head);
}
@Override
public Iterator<ReferenceEntry<K, V>> iterator() {
return new AbstractSequentialIterator<ReferenceEntry<K, V>>(peek()) {
@Override
protected ReferenceEntry<K, V> computeNext(ReferenceEntry<K, V> previous) {
ReferenceEntry<K, V> next = previous.getNextEvictable();
return (next == head) ? null : next;
}
};
}
}
/**
* A custom queue for managing expiration order. Note that this is tightly integrated with
* {@code ReferenceEntry}, upon which it reliese to perform its linking.
*
* <p>Note that this entire implementation makes the assumption that all elements which are in
* the map are also in this queue, and that all elements not in the queue are not in the map.
*
* <p>The benefits of creating our own queue are that (1) we can replace elements in the middle
* of the queue as part of copyEvictableEntry, and (2) the contains method is highly optimized
* for the current model.
*/
static final class ExpirationQueue<K, V> extends AbstractQueue<ReferenceEntry<K, V>> {
final ReferenceEntry<K, V> head = new AbstractReferenceEntry<K, V>() {
@Override
public long getExpirationTime() {
return Long.MAX_VALUE;
}
@Override
public void setExpirationTime(long time) {}
ReferenceEntry<K, V> nextExpirable = this;
@Override
public ReferenceEntry<K, V> getNextExpirable() {
return nextExpirable;
}
@Override
public void setNextExpirable(ReferenceEntry<K, V> next) {
this.nextExpirable = next;
}
ReferenceEntry<K, V> previousExpirable = this;
@Override
public ReferenceEntry<K, V> getPreviousExpirable() {
return previousExpirable;
}
@Override
public void setPreviousExpirable(ReferenceEntry<K, V> previous) {
this.previousExpirable = previous;
}
};
// implements Queue
@Override
public boolean offer(ReferenceEntry<K, V> entry) {
// unlink
connectExpirables(entry.getPreviousExpirable(), entry.getNextExpirable());
// add to tail
connectExpirables(head.getPreviousExpirable(), entry);
connectExpirables(entry, head);
return true;
}
@Override
public ReferenceEntry<K, V> peek() {
ReferenceEntry<K, V> next = head.getNextExpirable();
return (next == head) ? null : next;
}
@Override
public ReferenceEntry<K, V> poll() {
ReferenceEntry<K, V> next = head.getNextExpirable();
if (next == head) {
return null;
}
remove(next);
return next;
}
@Override
@SuppressWarnings("unchecked")
public boolean remove(Object o) {
ReferenceEntry<K, V> e = (ReferenceEntry) o;
ReferenceEntry<K, V> previous = e.getPreviousExpirable();
ReferenceEntry<K, V> next = e.getNextExpirable();
connectExpirables(previous, next);
nullifyExpirable(e);
return next != NullEntry.INSTANCE;
}
@Override
@SuppressWarnings("unchecked")
public boolean contains(Object o) {
ReferenceEntry<K, V> e = (ReferenceEntry) o;
return e.getNextExpirable() != NullEntry.INSTANCE;
}
@Override
public boolean isEmpty() {
return head.getNextExpirable() == head;
}
@Override
public int size() {
int size = 0;
for (ReferenceEntry<K, V> e = head.getNextExpirable(); e != head; e = e.getNextExpirable()) {
size++;
}
return size;
}
@Override
public void clear() {
ReferenceEntry<K, V> e = head.getNextExpirable();
while (e != head) {
ReferenceEntry<K, V> next = e.getNextExpirable();
nullifyExpirable(e);
e = next;
}
head.setNextExpirable(head);
head.setPreviousExpirable(head);
}
@Override
public Iterator<ReferenceEntry<K, V>> iterator() {
return new AbstractSequentialIterator<ReferenceEntry<K, V>>(peek()) {
@Override
protected ReferenceEntry<K, V> computeNext(ReferenceEntry<K, V> previous) {
ReferenceEntry<K, V> next = previous.getNextExpirable();
return (next == head) ? null : next;
}
};
}
}
static final class CleanupMapTask implements Runnable {
final WeakReference<MapMakerInternalMap<?, ?>> mapReference;
public CleanupMapTask(MapMakerInternalMap<?, ?> map) {
this.mapReference = new WeakReference<MapMakerInternalMap<?, ?>>(map);
}
@Override
public void run() {
MapMakerInternalMap<?, ?> map = mapReference.get();
if (map == null) {
throw new CancellationException();
}
for (Segment<?, ?> segment : map.segments) {
segment.runCleanup();
}
}
}
// ConcurrentMap methods
@Override
public boolean isEmpty() {
/*
* Sum per-segment modCounts to avoid mis-reporting when elements are concurrently added and
* removed in one segment while checking another, in which case the table was never actually
* empty at any point. (The sum ensures accuracy up through at least 1<<31 per-segment
* modifications before recheck.) Method containsValue() uses similar constructions for
* stability checks.
*/
long sum = 0L;
Segment<K, V>[] segments = this.segments;
for (int i = 0; i < segments.length; ++i) {
if (segments[i].count != 0) {
return false;
}
sum += segments[i].modCount;
}
if (sum != 0L) { // recheck unless no modifications
for (int i = 0; i < segments.length; ++i) {
if (segments[i].count != 0) {
return false;
}
sum -= segments[i].modCount;
}
if (sum != 0L) {
return false;
}
}
return true;
}
@Override
public int size() {
Segment<K, V>[] segments = this.segments;
long sum = 0;
for (int i = 0; i < segments.length; ++i) {
sum += segments[i].count;
}
return Ints.saturatedCast(sum);
}
@Override
public V get(@Nullable Object key) {
if (key == null) {
return null;
}
int hash = hash(key);
return segmentFor(hash).get(key, hash);
}
/**
* Returns the internal entry for the specified key. The entry may be computing, expired, or
* partially collected. Does not impact recency ordering.
*/
ReferenceEntry<K, V> getEntry(@Nullable Object key) {
if (key == null) {
return null;
}
int hash = hash(key);
return segmentFor(hash).getEntry(key, hash);
}
/**
* Returns the live internal entry for the specified key. Does not impact recency ordering.
*/
ReferenceEntry<K, V> getLiveEntry(@Nullable Object key) {
if (key == null) {
return null;
}
int hash = hash(key);
return segmentFor(hash).getLiveEntry(key, hash);
}
@Override
public boolean containsKey(@Nullable Object key) {
if (key == null) {
return false;
}
int hash = hash(key);
return segmentFor(hash).containsKey(key, hash);
}
@Override
public boolean containsValue(@Nullable Object value) {
if (value == null) {
return false;
}
// This implementation is patterned after ConcurrentHashMap, but without the locking. The only
// way for it to return a false negative would be for the target value to jump around in the map
// such that none of the subsequent iterations observed it, despite the fact that at every point
// in time it was present somewhere int the map. This becomes increasingly unlikely as
// CONTAINS_VALUE_RETRIES increases, though without locking it is theoretically possible.
final Segment<K,V>[] segments = this.segments;
long last = -1L;
for (int i = 0; i < CONTAINS_VALUE_RETRIES; i++) {
long sum = 0L;
for (Segment<K, V> segment : segments) {
// ensure visibility of most recent completed write
@SuppressWarnings({"UnusedDeclaration", "unused"})
int c = segment.count; // read-volatile
AtomicReferenceArray<ReferenceEntry<K, V>> table = segment.table;
for (int j = 0 ; j < table.length(); j++) {
for (ReferenceEntry<K, V> e = table.get(j); e != null; e = e.getNext()) {
V v = segment.getLiveValue(e);
if (v != null && valueEquivalence.equivalent(value, v)) {
return true;
}
}
}
sum += segment.modCount;
}
if (sum == last) {
break;
}
last = sum;
}
return false;
}
@Override
public V put(K key, V value) {
checkNotNull(key);
checkNotNull(value);
int hash = hash(key);
return segmentFor(hash).put(key, hash, value, false);
}
@Override
public V putIfAbsent(K key, V value) {
checkNotNull(key);
checkNotNull(value);
int hash = hash(key);
return segmentFor(hash).put(key, hash, value, true);
}
@Override
public void putAll(Map<? extends K, ? extends V> m) {
for (Entry<? extends K, ? extends V> e : m.entrySet()) {
put(e.getKey(), e.getValue());
}
}
@Override
public V remove(@Nullable Object key) {
if (key == null) {
return null;
}
int hash = hash(key);
return segmentFor(hash).remove(key, hash);
}
@Override
public boolean remove(@Nullable Object key, @Nullable Object value) {
if (key == null || value == null) {
return false;
}
int hash = hash(key);
return segmentFor(hash).remove(key, hash, value);
}
@Override
public boolean replace(K key, @Nullable V oldValue, V newValue) {
checkNotNull(key);
checkNotNull(newValue);
if (oldValue == null) {
return false;
}
int hash = hash(key);
return segmentFor(hash).replace(key, hash, oldValue, newValue);
}
@Override
public V replace(K key, V value) {
checkNotNull(key);
checkNotNull(value);
int hash = hash(key);
return segmentFor(hash).replace(key, hash, value);
}
@Override
public void clear() {
for (Segment<K, V> segment : segments) {
segment.clear();
}
}
Set<K> keySet;
@Override
public Set<K> keySet() {
Set<K> ks = keySet;
return (ks != null) ? ks : (keySet = new KeySet());
}
Collection<V> values;
@Override
public Collection<V> values() {
Collection<V> vs = values;
return (vs != null) ? vs : (values = new Values());
}
Set<Entry<K, V>> entrySet;
@Override
public Set<Entry<K, V>> entrySet() {
Set<Entry<K, V>> es = entrySet;
return (es != null) ? es : (entrySet = new EntrySet());
}
// Iterator Support
abstract class HashIterator {
int nextSegmentIndex;
int nextTableIndex;
Segment<K, V> currentSegment;
AtomicReferenceArray<ReferenceEntry<K, V>> currentTable;
ReferenceEntry<K, V> nextEntry;
WriteThroughEntry nextExternal;
WriteThroughEntry lastReturned;
HashIterator() {
nextSegmentIndex = segments.length - 1;
nextTableIndex = -1;
advance();
}
final void advance() {
nextExternal = null;
if (nextInChain()) {
return;
}
if (nextInTable()) {
return;
}
while (nextSegmentIndex >= 0) {
currentSegment = segments[nextSegmentIndex--];
if (currentSegment.count != 0) {
currentTable = currentSegment.table;
nextTableIndex = currentTable.length() - 1;
if (nextInTable()) {
return;
}
}
}
}
/**
* Finds the next entry in the current chain. Returns {@code true} if an entry was found.
*/
boolean nextInChain() {
if (nextEntry != null) {
for (nextEntry = nextEntry.getNext(); nextEntry != null; nextEntry = nextEntry.getNext()) {
if (advanceTo(nextEntry)) {
return true;
}
}
}
return false;
}
/**
* Finds the next entry in the current table. Returns {@code true} if an entry was found.
*/
boolean nextInTable() {
while (nextTableIndex >= 0) {
if ((nextEntry = currentTable.get(nextTableIndex--)) != null) {
if (advanceTo(nextEntry) || nextInChain()) {
return true;
}
}
}
return false;
}
/**
* Advances to the given entry. Returns {@code true} if the entry was valid, {@code false} if it
* should be skipped.
*/
boolean advanceTo(ReferenceEntry<K, V> entry) {
try {
K key = entry.getKey();
V value = getLiveValue(entry);
if (value != null) {
nextExternal = new WriteThroughEntry(key, value);
return true;
} else {
// Skip stale entry.
return false;
}
} finally {
currentSegment.postReadCleanup();
}
}
public boolean hasNext() {
return nextExternal != null;
}
WriteThroughEntry nextEntry() {
if (nextExternal == null) {
throw new NoSuchElementException();
}
lastReturned = nextExternal;
advance();
return lastReturned;
}
public void remove() {
checkState(lastReturned != null);
MapMakerInternalMap.this.remove(lastReturned.getKey());
lastReturned = null;
}
}
final class KeyIterator extends HashIterator implements Iterator<K> {
@Override
public K next() {
return nextEntry().getKey();
}
}
final class ValueIterator extends HashIterator implements Iterator<V> {
@Override
public V next() {
return nextEntry().getValue();
}
}
/**
* Custom Entry class used by EntryIterator.next(), that relays setValue changes to the
* underlying map.
*/
final class WriteThroughEntry extends AbstractMapEntry<K, V> {
final K key; // non-null
V value; // non-null
WriteThroughEntry(K key, V value) {
this.key = key;
this.value = value;
}
@Override
public K getKey() {
return key;
}
@Override
public V getValue() {
return value;
}
@Override
public boolean equals(@Nullable Object object) {
// Cannot use key and value equivalence
if (object instanceof Entry) {
Entry<?, ?> that = (Entry<?, ?>) object;
return key.equals(that.getKey()) && value.equals(that.getValue());
}
return false;
}
@Override
public int hashCode() {
// Cannot use key and value equivalence
return key.hashCode() ^ value.hashCode();
}
@Override
public V setValue(V newValue) {
V oldValue = put(key, newValue);
value = newValue; // only if put succeeds
return oldValue;
}
}
final class EntryIterator extends HashIterator implements Iterator<Entry<K, V>> {
@Override
public Entry<K, V> next() {
return nextEntry();
}
}
final class KeySet extends AbstractSet<K> {
@Override
public Iterator<K> iterator() {
return new KeyIterator();
}
@Override
public int size() {
return MapMakerInternalMap.this.size();
}
@Override
public boolean isEmpty() {
return MapMakerInternalMap.this.isEmpty();
}
@Override
public boolean contains(Object o) {
return MapMakerInternalMap.this.containsKey(o);
}
@Override
public boolean remove(Object o) {
return MapMakerInternalMap.this.remove(o) != null;
}
@Override
public void clear() {
MapMakerInternalMap.this.clear();
}
}
final class Values extends AbstractCollection<V> {
@Override
public Iterator<V> iterator() {
return new ValueIterator();
}
@Override
public int size() {
return MapMakerInternalMap.this.size();
}
@Override
public boolean isEmpty() {
return MapMakerInternalMap.this.isEmpty();
}
@Override
public boolean contains(Object o) {
return MapMakerInternalMap.this.containsValue(o);
}
@Override
public void clear() {
MapMakerInternalMap.this.clear();
}
}
final class EntrySet extends AbstractSet<Entry<K, V>> {
@Override
public Iterator<Entry<K, V>> iterator() {
return new EntryIterator();
}
@Override
public boolean contains(Object o) {
if (!(o instanceof Entry)) {
return false;
}
Entry<?, ?> e = (Entry<?, ?>) o;
Object key = e.getKey();
if (key == null) {
return false;
}
V v = MapMakerInternalMap.this.get(key);
return v != null && valueEquivalence.equivalent(e.getValue(), v);
}
@Override
public boolean remove(Object o) {
if (!(o instanceof Entry)) {
return false;
}
Entry<?, ?> e = (Entry<?, ?>) o;
Object key = e.getKey();
return key != null && MapMakerInternalMap.this.remove(key, e.getValue());
}
@Override
public int size() {
return MapMakerInternalMap.this.size();
}
@Override
public boolean isEmpty() {
return MapMakerInternalMap.this.isEmpty();
}
@Override
public void clear() {
MapMakerInternalMap.this.clear();
}
}
// Serialization Support
private static final long serialVersionUID = 5;
Object writeReplace() {
return new SerializationProxy<K, V>(keyStrength, valueStrength, keyEquivalence,
valueEquivalence, expireAfterWriteNanos, expireAfterAccessNanos, maximumSize,
concurrencyLevel, removalListener, this);
}
/**
* The actual object that gets serialized. Unfortunately, readResolve() doesn't get called when a
* circular dependency is present, so the proxy must be able to behave as the map itself.
*/
abstract static class AbstractSerializationProxy<K, V>
extends ForwardingConcurrentMap<K, V> implements Serializable {
private static final long serialVersionUID = 3;
final Strength keyStrength;
final Strength valueStrength;
final Equivalence<Object> keyEquivalence;
final Equivalence<Object> valueEquivalence;
final long expireAfterWriteNanos;
final long expireAfterAccessNanos;
final int maximumSize;
final int concurrencyLevel;
final RemovalListener<? super K, ? super V> removalListener;
transient ConcurrentMap<K, V> delegate;
AbstractSerializationProxy(Strength keyStrength, Strength valueStrength,
Equivalence<Object> keyEquivalence, Equivalence<Object> valueEquivalence,
long expireAfterWriteNanos, long expireAfterAccessNanos, int maximumSize,
int concurrencyLevel, RemovalListener<? super K, ? super V> removalListener,
ConcurrentMap<K, V> delegate) {
this.keyStrength = keyStrength;
this.valueStrength = valueStrength;
this.keyEquivalence = keyEquivalence;
this.valueEquivalence = valueEquivalence;
this.expireAfterWriteNanos = expireAfterWriteNanos;
this.expireAfterAccessNanos = expireAfterAccessNanos;
this.maximumSize = maximumSize;
this.concurrencyLevel = concurrencyLevel;
this.removalListener = removalListener;
this.delegate = delegate;
}
@Override
protected ConcurrentMap<K, V> delegate() {
return delegate;
}
void writeMapTo(ObjectOutputStream out) throws IOException {
out.writeInt(delegate.size());
for (Entry<K, V> entry : delegate.entrySet()) {
out.writeObject(entry.getKey());
out.writeObject(entry.getValue());
}
out.writeObject(null); // terminate entries
}
@SuppressWarnings("deprecation") // serialization of deprecated feature
MapMaker readMapMaker(ObjectInputStream in) throws IOException {
int size = in.readInt();
MapMaker mapMaker = new MapMaker()
.initialCapacity(size)
.setKeyStrength(keyStrength)
.setValueStrength(valueStrength)
.keyEquivalence(keyEquivalence)
.valueEquivalence(valueEquivalence)
.concurrencyLevel(concurrencyLevel);
mapMaker.removalListener(removalListener);
if (expireAfterWriteNanos > 0) {
mapMaker.expireAfterWrite(expireAfterWriteNanos, TimeUnit.NANOSECONDS);
}
if (expireAfterAccessNanos > 0) {
mapMaker.expireAfterAccess(expireAfterAccessNanos, TimeUnit.NANOSECONDS);
}
if (maximumSize != MapMaker.UNSET_INT) {
mapMaker.maximumSize(maximumSize);
}
return mapMaker;
}
@SuppressWarnings("unchecked")
void readEntries(ObjectInputStream in) throws IOException, ClassNotFoundException {
while (true) {
K key = (K) in.readObject();
if (key == null) {
break; // terminator
}
V value = (V) in.readObject();
delegate.put(key, value);
}
}
}
/**
* The actual object that gets serialized. Unfortunately, readResolve() doesn't get called when a
* circular dependency is present, so the proxy must be able to behave as the map itself.
*/
private static final class SerializationProxy<K, V> extends AbstractSerializationProxy<K, V> {
private static final long serialVersionUID = 3;
SerializationProxy(Strength keyStrength, Strength valueStrength,
Equivalence<Object> keyEquivalence, Equivalence<Object> valueEquivalence,
long expireAfterWriteNanos, long expireAfterAccessNanos, int maximumSize,
int concurrencyLevel, RemovalListener<? super K, ? super V> removalListener,
ConcurrentMap<K, V> delegate) {
super(keyStrength, valueStrength, keyEquivalence, valueEquivalence, expireAfterWriteNanos,
expireAfterAccessNanos, maximumSize, concurrencyLevel, removalListener, delegate);
}
private void writeObject(ObjectOutputStream out) throws IOException {
out.defaultWriteObject();
writeMapTo(out);
}
private void readObject(ObjectInputStream in) throws IOException, ClassNotFoundException {
in.defaultReadObject();
MapMaker mapMaker = readMapMaker(in);
delegate = mapMaker.makeMap();
readEntries(in);
}
private Object readResolve() {
return delegate;
}
}
}
| 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.GwtCompatible;
import java.io.Serializable;
import java.util.Collection;
import java.util.Iterator;
import javax.annotation.Nullable;
/**
* An immutable collection. Does not permit null elements.
*
* <p>In addition to the {@link Collection} methods, this class has an {@link
* #asList()} method, which returns a list view of the collection's elements.
*
* <p><b>Note:</b> Although this class is not final, it cannot be subclassed
* outside of this package as it has no public or protected constructors. Thus,
* instances of this type are guaranteed to be immutable.
*
* @author Jesse Wilson
* @since 2.0 (imported from Google Collections Library)
*/
@GwtCompatible(emulated = true)
@SuppressWarnings("serial") // we're overriding default serialization
public abstract class ImmutableCollection<E>
implements Collection<E>, Serializable {
static final ImmutableCollection<Object> EMPTY_IMMUTABLE_COLLECTION
= new EmptyImmutableCollection();
ImmutableCollection() {}
/**
* Returns an unmodifiable iterator across the elements in this collection.
*/
@Override
public abstract UnmodifiableIterator<E> iterator();
@Override
public Object[] toArray() {
return ObjectArrays.toArrayImpl(this);
}
@Override
public <T> T[] toArray(T[] other) {
return ObjectArrays.toArrayImpl(this, other);
}
@Override
public boolean contains(@Nullable Object object) {
return object != null && Iterators.contains(iterator(), object);
}
@Override
public boolean containsAll(Collection<?> targets) {
return Collections2.containsAllImpl(this, targets);
}
@Override
public boolean isEmpty() {
return size() == 0;
}
@Override public String toString() {
return Collections2.toStringImpl(this);
}
/**
* Guaranteed to throw an exception and leave the collection unmodified.
*
* @throws UnsupportedOperationException always
*/
@Override
public final boolean add(E e) {
throw new UnsupportedOperationException();
}
/**
* Guaranteed to throw an exception and leave the collection unmodified.
*
* @throws UnsupportedOperationException always
*/
@Override
public final boolean remove(Object object) {
throw new UnsupportedOperationException();
}
/**
* Guaranteed to throw an exception and leave the collection unmodified.
*
* @throws UnsupportedOperationException always
*/
@Override
public final boolean addAll(Collection<? extends E> newElements) {
throw new UnsupportedOperationException();
}
/**
* Guaranteed to throw an exception and leave the collection unmodified.
*
* @throws UnsupportedOperationException always
*/
@Override
public final boolean removeAll(Collection<?> oldElements) {
throw new UnsupportedOperationException();
}
/**
* Guaranteed to throw an exception and leave the collection unmodified.
*
* @throws UnsupportedOperationException always
*/
@Override
public final boolean retainAll(Collection<?> elementsToKeep) {
throw new UnsupportedOperationException();
}
/**
* Guaranteed to throw an exception and leave the collection unmodified.
*
* @throws UnsupportedOperationException always
*/
@Override
public final void clear() {
throw new UnsupportedOperationException();
}
/*
* TODO(kevinb): Restructure code so ImmutableList doesn't contain this
* variable, which it doesn't use.
*/
private transient ImmutableList<E> asList;
/**
* Returns a list view of the collection.
*
* @since 2.0
*/
public ImmutableList<E> asList() {
ImmutableList<E> list = asList;
return (list == null) ? (asList = createAsList()) : list;
}
ImmutableList<E> createAsList() {
switch (size()) {
case 0:
return ImmutableList.of();
case 1:
return ImmutableList.of(iterator().next());
default:
return new ImmutableAsList<E>(toArray(), this);
}
}
abstract boolean isPartialView();
private static class EmptyImmutableCollection
extends ImmutableCollection<Object> {
@Override
public int size() {
return 0;
}
@Override public boolean isEmpty() {
return true;
}
@Override public boolean contains(@Nullable Object object) {
return false;
}
@Override public UnmodifiableIterator<Object> iterator() {
return Iterators.EMPTY_ITERATOR;
}
private static final Object[] EMPTY_ARRAY = new Object[0];
@Override public Object[] toArray() {
return EMPTY_ARRAY;
}
@Override public <T> T[] toArray(T[] array) {
if (array.length > 0) {
array[0] = null;
}
return array;
}
@Override ImmutableList<Object> createAsList() {
return ImmutableList.of();
}
@Override boolean isPartialView() {
return false;
}
}
/**
* Nonempty collection stored in an array.
*/
private static class ArrayImmutableCollection<E>
extends ImmutableCollection<E> {
private final E[] elements;
ArrayImmutableCollection(E[] elements) {
this.elements = elements;
}
@Override
public int size() {
return elements.length;
}
@Override public boolean isEmpty() {
return false;
}
@Override public UnmodifiableIterator<E> iterator() {
return Iterators.forArray(elements);
}
@Override ImmutableList<E> createAsList() {
return elements.length == 1 ? new SingletonImmutableList<E>(elements[0])
: new RegularImmutableList<E>(elements);
}
@Override boolean isPartialView() {
return false;
}
}
/*
* Serializes ImmutableCollections as their logical contents. This ensures
* that implementation types do not leak into the serialized representation.
*/
private static class SerializedForm implements Serializable {
final Object[] elements;
SerializedForm(Object[] elements) {
this.elements = elements;
}
Object readResolve() {
return elements.length == 0
? EMPTY_IMMUTABLE_COLLECTION
: new ArrayImmutableCollection<Object>(Platform.clone(elements));
}
private static final long serialVersionUID = 0;
}
Object writeReplace() {
return new SerializedForm(toArray());
}
/**
* Abstract base class for builders of {@link ImmutableCollection} types.
*
* @since 10.0
*/
public abstract static class Builder<E> {
Builder() {
}
/**
* Adds {@code element} to the {@code ImmutableCollection} being built.
*
* <p>Note that each builder class covariantly returns its own type from
* this method.
*
* @param element the element to add
* @return this {@code Builder} instance
* @throws NullPointerException if {@code element} is null
*/
public abstract Builder<E> add(E element);
/**
* Adds each element of {@code elements} to the {@code ImmutableCollection}
* being built.
*
* <p>Note that each builder class overrides this method in order to
* covariantly return its own type.
*
* @param elements the elements to add
* @return this {@code Builder} instance
* @throws NullPointerException if {@code elements} is null or contains a
* null element
*/
public Builder<E> add(E... elements) {
for (E element : elements) {
add(element);
}
return this;
}
/**
* Adds each element of {@code elements} to the {@code ImmutableCollection}
* being built.
*
* <p>Note that each builder class overrides this method in order to
* covariantly return its own type.
*
* @param elements the elements to add
* @return this {@code Builder} instance
* @throws NullPointerException if {@code elements} is null or contains a
* null element
*/
public Builder<E> addAll(Iterable<? extends E> elements) {
for (E element : elements) {
add(element);
}
return this;
}
/**
* Adds each element of {@code elements} to the {@code ImmutableCollection}
* being built.
*
* <p>Note that each builder class overrides this method in order to
* covariantly return its own type.
*
* @param elements the elements to add
* @return this {@code Builder} instance
* @throws NullPointerException if {@code elements} is null or contains a
* null element
*/
public Builder<E> addAll(Iterator<? extends E> elements) {
while (elements.hasNext()) {
add(elements.next());
}
return this;
}
/**
* Returns a newly-created {@code ImmutableCollection} of the appropriate
* type, containing the elements provided to this builder.
*
* <p>Note that each builder class covariantly returns the appropriate type
* of {@code ImmutableCollection} from this method.
*/
public abstract ImmutableCollection<E> build();
}
}
| 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.GwtCompatible;
/**
* Bimap with one or more mappings.
*
* @author Jared Levy
*/
@GwtCompatible(serializable = true, emulated = true)
@SuppressWarnings("serial") // uses writeReplace(), not default serialization
class RegularImmutableBiMap<K, V> extends ImmutableBiMap<K, V> {
final transient ImmutableMap<K, V> delegate;
final transient ImmutableBiMap<V, K> inverse;
RegularImmutableBiMap(ImmutableMap<K, V> delegate) {
this.delegate = delegate;
ImmutableMap.Builder<V, K> builder = ImmutableMap.builder();
for (Entry<K, V> entry : delegate.entrySet()) {
builder.put(entry.getValue(), entry.getKey());
}
ImmutableMap<V, K> backwardMap = builder.build();
this.inverse = new RegularImmutableBiMap<V, K>(backwardMap, this);
}
RegularImmutableBiMap(ImmutableMap<K, V> delegate,
ImmutableBiMap<V, K> inverse) {
this.delegate = delegate;
this.inverse = inverse;
}
@Override ImmutableMap<K, V> delegate() {
return delegate;
}
@Override public ImmutableBiMap<V, K> inverse() {
return inverse;
}
@Override boolean isPartialView() {
return delegate.isPartialView() || inverse.delegate().isPartialView();
}
}
| 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 com.google.common.collect.Multiset.Entry;
import java.util.Comparator;
import java.util.Iterator;
import java.util.NoSuchElementException;
import java.util.Set;
import java.util.SortedSet;
/**
* Provides static utility methods for creating and working with
* {@link SortedMultiset} instances.
*
* @author Louis Wasserman
*/
@GwtCompatible
final class SortedMultisets {
private SortedMultisets() {
}
/**
* A skeleton implementation for {@link SortedMultiset#elementSet}.
*/
static abstract class ElementSet<E> extends Multisets.ElementSet<E> implements
SortedSet<E> {
@Override abstract SortedMultiset<E> multiset();
@Override public Comparator<? super E> comparator() {
return multiset().comparator();
}
@Override public SortedSet<E> subSet(E fromElement, E toElement) {
return multiset().subMultiset(fromElement, BoundType.CLOSED, toElement,
BoundType.OPEN).elementSet();
}
@Override public SortedSet<E> headSet(E toElement) {
return multiset().headMultiset(toElement, BoundType.OPEN).elementSet();
}
@Override public SortedSet<E> tailSet(E fromElement) {
return multiset().tailMultiset(fromElement, BoundType.CLOSED)
.elementSet();
}
@Override public E first() {
return getElementOrThrow(multiset().firstEntry());
}
@Override public E last() {
return getElementOrThrow(multiset().lastEntry());
}
}
private static <E> E getElementOrThrow(Entry<E> entry) {
if (entry == null) {
throw new NoSuchElementException();
}
return entry.getElement();
}
/**
* A skeleton implementation of a descending multiset. Only needs
* {@code forwardMultiset()} and {@code entryIterator()}.
*/
static abstract class DescendingMultiset<E> extends ForwardingMultiset<E>
implements SortedMultiset<E> {
abstract SortedMultiset<E> forwardMultiset();
private transient Comparator<? super E> comparator;
@Override public Comparator<? super E> comparator() {
Comparator<? super E> result = comparator;
if (result == null) {
return comparator =
Ordering.from(forwardMultiset().comparator()).<E>reverse();
}
return result;
}
private transient SortedSet<E> elementSet;
@Override public SortedSet<E> elementSet() {
SortedSet<E> result = elementSet;
if (result == null) {
return elementSet = new SortedMultisets.ElementSet<E>() {
@Override SortedMultiset<E> multiset() {
return DescendingMultiset.this;
}
};
}
return result;
}
@Override public Entry<E> pollFirstEntry() {
return forwardMultiset().pollLastEntry();
}
@Override public Entry<E> pollLastEntry() {
return forwardMultiset().pollFirstEntry();
}
@Override public SortedMultiset<E> headMultiset(E toElement,
BoundType boundType) {
return forwardMultiset().tailMultiset(toElement, boundType)
.descendingMultiset();
}
@Override public SortedMultiset<E> subMultiset(E fromElement,
BoundType fromBoundType, E toElement, BoundType toBoundType) {
return forwardMultiset().subMultiset(toElement, toBoundType, fromElement,
fromBoundType).descendingMultiset();
}
@Override public SortedMultiset<E> tailMultiset(E fromElement,
BoundType boundType) {
return forwardMultiset().headMultiset(fromElement, boundType)
.descendingMultiset();
}
@Override protected Multiset<E> delegate() {
return forwardMultiset();
}
@Override public SortedMultiset<E> descendingMultiset() {
return forwardMultiset();
}
@Override public Entry<E> firstEntry() {
return forwardMultiset().lastEntry();
}
@Override public Entry<E> lastEntry() {
return forwardMultiset().firstEntry();
}
abstract Iterator<Entry<E>> entryIterator();
private transient Set<Entry<E>> entrySet;
@Override public Set<Entry<E>> entrySet() {
Set<Entry<E>> result = entrySet;
return (result == null) ? entrySet = createEntrySet() : result;
}
Set<Entry<E>> createEntrySet() {
return new Multisets.EntrySet<E>() {
@Override Multiset<E> multiset() {
return DescendingMultiset.this;
}
@Override public Iterator<Entry<E>> iterator() {
return entryIterator();
}
@Override public int size() {
return forwardMultiset().entrySet().size();
}
};
}
@Override public Iterator<E> iterator() {
return Multisets.iteratorImpl(this);
}
@Override public Object[] toArray() {
return standardToArray();
}
@Override public <T> T[] toArray(T[] array) {
return standardToArray(array);
}
@Override public String toString() {
return entrySet().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.collect;
import com.google.common.annotations.GwtCompatible;
import java.util.Collection;
import java.util.Comparator;
import java.util.Map;
import java.util.Set;
import java.util.SortedSet;
import javax.annotation.Nullable;
/**
* A {@code SetMultimap} whose set of values for a given key are kept sorted;
* that is, they comprise a {@link SortedSet}. It cannot hold duplicate
* key-value pairs; adding a key-value pair that's already in the multimap has
* no effect. This interface does not specify the ordering of the multimap's
* keys.
*
* <p>The {@link #get}, {@link #removeAll}, and {@link #replaceValues} methods
* each return a {@link SortedSet} of values, while {@link Multimap#entries()}
* returns a {@link Set} of map entries. Though the method signature doesn't say
* so explicitly, the map returned by {@link #asMap} has {@code SortedSet}
* values.
*
* <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
public interface SortedSetMultimap<K, V> extends SetMultimap<K, V> {
// Following Javadoc copied from Multimap.
/**
* Returns a collection view of all values associated with a key. If no
* mappings in the multimap have the provided key, an empty collection is
* returned.
*
* <p>Changes to the returned collection will update the underlying multimap,
* and vice versa.
*
* <p>Because a {@code SortedSetMultimap} has unique sorted values for a given
* key, this method returns a {@link SortedSet}, instead of the
* {@link java.util.Collection} specified in the {@link Multimap} interface.
*/
@Override
SortedSet<V> get(@Nullable K key);
/**
* Removes all values associated with a given key.
*
* <p>Because a {@code SortedSetMultimap} has unique sorted values for a given
* key, this method returns a {@link SortedSet}, instead of the
* {@link java.util.Collection} specified in the {@link Multimap} interface.
*/
@Override
SortedSet<V> removeAll(@Nullable Object key);
/**
* Stores a collection of values with the same key, replacing any existing
* values for that key.
*
* <p>Because a {@code SortedSetMultimap} has unique sorted values for a given
* key, this method returns a {@link SortedSet}, instead of the
* {@link java.util.Collection} specified in the {@link Multimap} interface.
*
* <p>Any duplicates in {@code values} will be stored in the multimap once.
*/
@Override
SortedSet<V> replaceValues(K key, Iterable<? extends V> values);
/**
* Returns a map view that associates each key with the corresponding values
* in the multimap. Changes to the returned map, such as element removal, will
* update the underlying multimap. The map does not support {@code setValue()}
* on its entries, {@code put}, or {@code putAll}.
*
* <p>When passed a key that is present in the map, {@code
* asMap().get(Object)} has the same behavior as {@link #get}, returning a
* live collection. When passed a key that is not present, however, {@code
* asMap().get(Object)} returns {@code null} instead of an empty collection.
*
* <p>Though the method signature doesn't say so explicitly, the returned map
* has {@link SortedSet} values.
*/
@Override
Map<K, Collection<V>> asMap();
/**
* Returns the comparator that orders the multimap values, with {@code null}
* indicating that natural ordering is used.
*/
Comparator<? super V> valueComparator();
}
| 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.ListIterator;
/**
* A list iterator which forwards all its method calls to another list
* iterator. Subclasses should override one or more methods to modify the
* behavior of the backing iterator as desired per the <a
* href="http://en.wikipedia.org/wiki/Decorator_pattern">decorator pattern</a>.
*
* @author Mike Bostock
* @since 2.0 (imported from Google Collections Library)
*/
@GwtCompatible
public abstract class ForwardingListIterator<E> extends ForwardingIterator<E>
implements ListIterator<E> {
/** Constructor for use by subclasses. */
protected ForwardingListIterator() {}
@Override protected abstract ListIterator<E> delegate();
@Override
public void add(E element) {
delegate().add(element);
}
@Override
public boolean hasPrevious() {
return delegate().hasPrevious();
}
@Override
public int nextIndex() {
return delegate().nextIndex();
}
@Override
public E previous() {
return delegate().previous();
}
@Override
public int previousIndex() {
return delegate().previousIndex();
}
@Override
public void set(E element) {
delegate().set(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.GwtCompatible;
import java.io.Serializable;
import java.util.AbstractCollection;
import java.util.AbstractMap;
import java.util.Collection;
import java.util.Collections;
import java.util.Comparator;
import java.util.ConcurrentModificationException;
import java.util.Iterator;
import java.util.List;
import java.util.ListIterator;
import java.util.Map;
import java.util.Map.Entry;
import java.util.RandomAccess;
import java.util.Set;
import java.util.SortedMap;
import java.util.SortedSet;
import javax.annotation.Nullable;
/**
* Basic implementation of the {@link Multimap} interface. This class represents
* a multimap as a map that associates each key with a collection of values. All
* methods of {@link Multimap} are supported, including those specified as
* optional in the interface.
*
* <p>To implement a multimap, a subclass must define the method {@link
* #createCollection()}, which creates an empty collection of values for a key.
*
* <p>The multimap constructor takes a map that has a single entry for each
* distinct key. When you insert a key-value pair with a key that isn't already
* in the multimap, {@code AbstractMultimap} calls {@link #createCollection()}
* to create the collection of values for that key. The subclass should not call
* {@link #createCollection()} directly, and a new instance should be created
* every time the method is called.
*
* <p>For example, the subclass could pass a {@link java.util.TreeMap} during
* construction, and {@link #createCollection()} could return a {@link
* java.util.TreeSet}, in which case the multimap's iterators would propagate
* through the keys and values in sorted order.
*
* <p>Keys and values may be null, as long as the underlying collection classes
* support null elements.
*
* <p>The collections created by {@link #createCollection()} may or may not
* allow duplicates. If the collection, such as a {@link Set}, does not support
* duplicates, an added key-value pair will replace an existing pair with the
* same key and value, if such a pair is present. With collections like {@link
* List} that allow duplicates, the collection will keep the existing key-value
* pairs while adding a new pair.
*
* <p>This class is not threadsafe when any concurrent operations update the
* multimap, even if the underlying map and {@link #createCollection()} method
* return threadsafe classes. Concurrent read operations will work correctly. To
* allow concurrent update operations, wrap your multimap with a call to {@link
* Multimaps#synchronizedMultimap}.
*
* <p>For serialization to work, the subclass must specify explicit
* {@code readObject} and {@code writeObject} methods.
*
* @author Jared Levy
* @author Louis Wasserman
*/
@GwtCompatible
abstract class AbstractMultimap<K, V> implements Multimap<K, V>, Serializable {
/*
* Here's an outline of the overall design.
*
* The map variable contains the collection of values associated with each
* key. When a key-value pair is added to a multimap that didn't previously
* contain any values for that key, a new collection generated by
* createCollection is added to the map. That same collection instance
* remains in the map as long as the multimap has any values for the key. If
* all values for the key are removed, the key and collection are removed
* from the map.
*
* The get method returns a WrappedCollection, which decorates the collection
* in the map (if the key is present) or an empty collection (if the key is
* not present). When the collection delegate in the WrappedCollection is
* empty, the multimap may contain subsequently added values for that key. To
* handle that situation, the WrappedCollection checks whether map contains
* an entry for the provided key, and if so replaces the delegate.
*/
private transient Map<K, Collection<V>> map;
private transient int totalSize;
/**
* Creates a new multimap that uses the provided map.
*
* @param map place to store the mapping from each key to its corresponding
* values
* @throws IllegalArgumentException if {@code map} is not empty
*/
protected AbstractMultimap(Map<K, Collection<V>> map) {
checkArgument(map.isEmpty());
this.map = map;
}
/** Used during deserialization only. */
final void setMap(Map<K, Collection<V>> map) {
this.map = map;
totalSize = 0;
for (Collection<V> values : map.values()) {
checkArgument(!values.isEmpty());
totalSize += values.size();
}
}
/**
* Creates the collection of values for a single key.
*
* <p>Collections with weak, soft, or phantom references are not supported.
* Each call to {@code createCollection} should create a new instance.
*
* <p>The returned collection class determines whether duplicate key-value
* pairs are allowed.
*
* @return an empty collection of values
*/
abstract Collection<V> createCollection();
/**
* Creates the collection of values for an explicitly provided key. By
* default, it simply calls {@link #createCollection()}, which is the correct
* behavior for most implementations. The {@link LinkedHashMultimap} class
* overrides it.
*
* @param key key to associate with values in the collection
* @return an empty collection of values
*/
Collection<V> createCollection(@Nullable K key) {
return createCollection();
}
Map<K, Collection<V>> backingMap() {
return map;
}
// Query Operations
@Override
public int size() {
return totalSize;
}
@Override
public boolean isEmpty() {
return totalSize == 0;
}
@Override
public boolean containsKey(@Nullable Object key) {
return map.containsKey(key);
}
@Override
public boolean containsValue(@Nullable Object value) {
for (Collection<V> collection : map.values()) {
if (collection.contains(value)) {
return true;
}
}
return false;
}
@Override
public boolean containsEntry(@Nullable Object key, @Nullable Object value) {
Collection<V> collection = map.get(key);
return collection != null && collection.contains(value);
}
// Modification Operations
@Override
public boolean put(@Nullable K key, @Nullable V value) {
Collection<V> collection = getOrCreateCollection(key);
if (collection.add(value)) {
totalSize++;
return true;
} else {
return false;
}
}
private Collection<V> getOrCreateCollection(@Nullable K key) {
Collection<V> collection = map.get(key);
if (collection == null) {
collection = createCollection(key);
map.put(key, collection);
}
return collection;
}
@Override
public boolean remove(@Nullable Object key, @Nullable Object value) {
Collection<V> collection = map.get(key);
if (collection == null) {
return false;
}
boolean changed = collection.remove(value);
if (changed) {
totalSize--;
if (collection.isEmpty()) {
map.remove(key);
}
}
return changed;
}
// Bulk Operations
@Override
public boolean putAll(@Nullable K key, Iterable<? extends V> values) {
if (!values.iterator().hasNext()) {
return false;
}
Collection<V> collection = getOrCreateCollection(key);
int oldSize = collection.size();
boolean changed = false;
if (values instanceof Collection) {
Collection<? extends V> c = Collections2.cast(values);
changed = collection.addAll(c);
} else {
for (V value : values) {
changed |= collection.add(value);
}
}
totalSize += (collection.size() - oldSize);
return changed;
}
@Override
public boolean putAll(Multimap<? extends K, ? extends V> multimap) {
boolean changed = false;
for (Map.Entry<? extends K, ? extends V> entry : multimap.entries()) {
changed |= put(entry.getKey(), entry.getValue());
}
return changed;
}
/**
* {@inheritDoc}
*
* <p>The returned collection is immutable.
*/
@Override
public Collection<V> replaceValues(
@Nullable K key, Iterable<? extends V> values) {
Iterator<? extends V> iterator = values.iterator();
if (!iterator.hasNext()) {
return removeAll(key);
}
Collection<V> collection = getOrCreateCollection(key);
Collection<V> oldValues = createCollection();
oldValues.addAll(collection);
totalSize -= collection.size();
collection.clear();
while (iterator.hasNext()) {
if (collection.add(iterator.next())) {
totalSize++;
}
}
return unmodifiableCollectionSubclass(oldValues);
}
/**
* {@inheritDoc}
*
* <p>The returned collection is immutable.
*/
@Override
public Collection<V> removeAll(@Nullable Object key) {
Collection<V> collection = map.remove(key);
Collection<V> output = createCollection();
if (collection != null) {
output.addAll(collection);
totalSize -= collection.size();
collection.clear();
}
return unmodifiableCollectionSubclass(output);
}
private Collection<V> unmodifiableCollectionSubclass(
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);
} else {
return Collections.unmodifiableCollection(collection);
}
}
@Override
public void clear() {
// Clear each collection, to make previously returned collections empty.
for (Collection<V> collection : map.values()) {
collection.clear();
}
map.clear();
totalSize = 0;
}
// Views
/**
* {@inheritDoc}
*
* <p>The returned collection is not serializable.
*/
@Override
public Collection<V> get(@Nullable K key) {
Collection<V> collection = map.get(key);
if (collection == null) {
collection = createCollection(key);
}
return wrapCollection(key, collection);
}
/**
* Generates a decorated collection that remains consistent with the values in
* the multimap for the provided key. Changes to the multimap may alter the
* returned collection, and vice versa.
*/
private Collection<V> wrapCollection(
@Nullable K key, Collection<V> collection) {
if (collection instanceof SortedSet) {
return new WrappedSortedSet(key, (SortedSet<V>) collection, null);
} else if (collection instanceof Set) {
return new WrappedSet(key, (Set<V>) collection);
} else if (collection instanceof List) {
return wrapList(key, (List<V>) collection, null);
} else {
return new WrappedCollection(key, collection, null);
}
}
private List<V> wrapList(
@Nullable K key, List<V> list, @Nullable WrappedCollection ancestor) {
return (list instanceof RandomAccess)
? new RandomAccessWrappedList(key, list, ancestor)
: new WrappedList(key, list, ancestor);
}
/**
* Collection decorator that stays in sync with the multimap values for a key.
* There are two kinds of wrapped collections: full and subcollections. Both
* have a delegate pointing to the underlying collection class.
*
* <p>Full collections, identified by a null ancestor field, contain all
* multimap values for a given key. Its delegate is a value in {@link
* AbstractMultimap#map} whenever the delegate is non-empty. The {@code
* refreshIfEmpty}, {@code removeIfEmpty}, and {@code addToMap} methods ensure
* that the {@code WrappedCollection} and map remain consistent.
*
* <p>A subcollection, such as a sublist, contains some of the values for a
* given key. Its ancestor field points to the full wrapped collection with
* all values for the key. The subcollection {@code refreshIfEmpty}, {@code
* removeIfEmpty}, and {@code addToMap} methods call the corresponding methods
* of the full wrapped collection.
*/
private class WrappedCollection extends AbstractCollection<V> {
final K key;
Collection<V> delegate;
final WrappedCollection ancestor;
final Collection<V> ancestorDelegate;
WrappedCollection(@Nullable K key, Collection<V> delegate,
@Nullable WrappedCollection ancestor) {
this.key = key;
this.delegate = delegate;
this.ancestor = ancestor;
this.ancestorDelegate
= (ancestor == null) ? null : ancestor.getDelegate();
}
/**
* If the delegate collection is empty, but the multimap has values for the
* key, replace the delegate with the new collection for the key.
*
* <p>For a subcollection, refresh its ancestor and validate that the
* ancestor delegate hasn't changed.
*/
void refreshIfEmpty() {
if (ancestor != null) {
ancestor.refreshIfEmpty();
if (ancestor.getDelegate() != ancestorDelegate) {
throw new ConcurrentModificationException();
}
} else if (delegate.isEmpty()) {
Collection<V> newDelegate = map.get(key);
if (newDelegate != null) {
delegate = newDelegate;
}
}
}
/**
* If collection is empty, remove it from {@code AbstractMultimap.this.map}.
* For subcollections, check whether the ancestor collection is empty.
*/
void removeIfEmpty() {
if (ancestor != null) {
ancestor.removeIfEmpty();
} else if (delegate.isEmpty()) {
map.remove(key);
}
}
K getKey() {
return key;
}
/**
* Add the delegate to the map. Other {@code WrappedCollection} methods
* should call this method after adding elements to a previously empty
* collection.
*
* <p>Subcollection add the ancestor's delegate instead.
*/
void addToMap() {
if (ancestor != null) {
ancestor.addToMap();
} else {
map.put(key, delegate);
}
}
@Override public int size() {
refreshIfEmpty();
return delegate.size();
}
@Override public boolean equals(@Nullable Object object) {
if (object == this) {
return true;
}
refreshIfEmpty();
return delegate.equals(object);
}
@Override public int hashCode() {
refreshIfEmpty();
return delegate.hashCode();
}
@Override public String toString() {
refreshIfEmpty();
return delegate.toString();
}
Collection<V> getDelegate() {
return delegate;
}
@Override public Iterator<V> iterator() {
refreshIfEmpty();
return new WrappedIterator();
}
/** Collection iterator for {@code WrappedCollection}. */
class WrappedIterator implements Iterator<V> {
final Iterator<V> delegateIterator;
final Collection<V> originalDelegate = delegate;
WrappedIterator() {
delegateIterator = iteratorOrListIterator(delegate);
}
WrappedIterator(Iterator<V> delegateIterator) {
this.delegateIterator = delegateIterator;
}
/**
* If the delegate changed since the iterator was created, the iterator is
* no longer valid.
*/
void validateIterator() {
refreshIfEmpty();
if (delegate != originalDelegate) {
throw new ConcurrentModificationException();
}
}
@Override
public boolean hasNext() {
validateIterator();
return delegateIterator.hasNext();
}
@Override
public V next() {
validateIterator();
return delegateIterator.next();
}
@Override
public void remove() {
delegateIterator.remove();
totalSize--;
removeIfEmpty();
}
Iterator<V> getDelegateIterator() {
validateIterator();
return delegateIterator;
}
}
@Override public boolean add(V value) {
refreshIfEmpty();
boolean wasEmpty = delegate.isEmpty();
boolean changed = delegate.add(value);
if (changed) {
totalSize++;
if (wasEmpty) {
addToMap();
}
}
return changed;
}
WrappedCollection getAncestor() {
return ancestor;
}
// The following methods are provided for better performance.
@Override public boolean addAll(Collection<? extends V> collection) {
if (collection.isEmpty()) {
return false;
}
int oldSize = size(); // calls refreshIfEmpty
boolean changed = delegate.addAll(collection);
if (changed) {
int newSize = delegate.size();
totalSize += (newSize - oldSize);
if (oldSize == 0) {
addToMap();
}
}
return changed;
}
@Override public boolean contains(Object o) {
refreshIfEmpty();
return delegate.contains(o);
}
@Override public boolean containsAll(Collection<?> c) {
refreshIfEmpty();
return delegate.containsAll(c);
}
@Override public void clear() {
int oldSize = size(); // calls refreshIfEmpty
if (oldSize == 0) {
return;
}
delegate.clear();
totalSize -= oldSize;
removeIfEmpty(); // maybe shouldn't be removed if this is a sublist
}
@Override public boolean remove(Object o) {
refreshIfEmpty();
boolean changed = delegate.remove(o);
if (changed) {
totalSize--;
removeIfEmpty();
}
return changed;
}
@Override public boolean removeAll(Collection<?> c) {
if (c.isEmpty()) {
return false;
}
int oldSize = size(); // calls refreshIfEmpty
boolean changed = delegate.removeAll(c);
if (changed) {
int newSize = delegate.size();
totalSize += (newSize - oldSize);
removeIfEmpty();
}
return changed;
}
@Override public boolean retainAll(Collection<?> c) {
checkNotNull(c);
int oldSize = size(); // calls refreshIfEmpty
boolean changed = delegate.retainAll(c);
if (changed) {
int newSize = delegate.size();
totalSize += (newSize - oldSize);
removeIfEmpty();
}
return changed;
}
}
private Iterator<V> iteratorOrListIterator(Collection<V> collection) {
return (collection instanceof List)
? ((List<V>) collection).listIterator()
: collection.iterator();
}
/** Set decorator that stays in sync with the multimap values for a key. */
private class WrappedSet extends WrappedCollection implements Set<V> {
WrappedSet(@Nullable K key, Set<V> delegate) {
super(key, delegate, null);
}
}
/**
* SortedSet decorator that stays in sync with the multimap values for a key.
*/
private class WrappedSortedSet extends WrappedCollection
implements SortedSet<V> {
WrappedSortedSet(@Nullable K key, SortedSet<V> delegate,
@Nullable WrappedCollection ancestor) {
super(key, delegate, ancestor);
}
SortedSet<V> getSortedSetDelegate() {
return (SortedSet<V>) getDelegate();
}
@Override
public Comparator<? super V> comparator() {
return getSortedSetDelegate().comparator();
}
@Override
public V first() {
refreshIfEmpty();
return getSortedSetDelegate().first();
}
@Override
public V last() {
refreshIfEmpty();
return getSortedSetDelegate().last();
}
@Override
public SortedSet<V> headSet(V toElement) {
refreshIfEmpty();
return new WrappedSortedSet(
getKey(), getSortedSetDelegate().headSet(toElement),
(getAncestor() == null) ? this : getAncestor());
}
@Override
public SortedSet<V> subSet(V fromElement, V toElement) {
refreshIfEmpty();
return new WrappedSortedSet(
getKey(), getSortedSetDelegate().subSet(fromElement, toElement),
(getAncestor() == null) ? this : getAncestor());
}
@Override
public SortedSet<V> tailSet(V fromElement) {
refreshIfEmpty();
return new WrappedSortedSet(
getKey(), getSortedSetDelegate().tailSet(fromElement),
(getAncestor() == null) ? this : getAncestor());
}
}
/** List decorator that stays in sync with the multimap values for a key. */
private class WrappedList extends WrappedCollection implements List<V> {
WrappedList(@Nullable K key, List<V> delegate,
@Nullable WrappedCollection ancestor) {
super(key, delegate, ancestor);
}
List<V> getListDelegate() {
return (List<V>) getDelegate();
}
@Override
public boolean addAll(int index, Collection<? extends V> c) {
if (c.isEmpty()) {
return false;
}
int oldSize = size(); // calls refreshIfEmpty
boolean changed = getListDelegate().addAll(index, c);
if (changed) {
int newSize = getDelegate().size();
totalSize += (newSize - oldSize);
if (oldSize == 0) {
addToMap();
}
}
return changed;
}
@Override
public V get(int index) {
refreshIfEmpty();
return getListDelegate().get(index);
}
@Override
public V set(int index, V element) {
refreshIfEmpty();
return getListDelegate().set(index, element);
}
@Override
public void add(int index, V element) {
refreshIfEmpty();
boolean wasEmpty = getDelegate().isEmpty();
getListDelegate().add(index, element);
totalSize++;
if (wasEmpty) {
addToMap();
}
}
@Override
public V remove(int index) {
refreshIfEmpty();
V value = getListDelegate().remove(index);
totalSize--;
removeIfEmpty();
return value;
}
@Override
public int indexOf(Object o) {
refreshIfEmpty();
return getListDelegate().indexOf(o);
}
@Override
public int lastIndexOf(Object o) {
refreshIfEmpty();
return getListDelegate().lastIndexOf(o);
}
@Override
public ListIterator<V> listIterator() {
refreshIfEmpty();
return new WrappedListIterator();
}
@Override
public ListIterator<V> listIterator(int index) {
refreshIfEmpty();
return new WrappedListIterator(index);
}
@Override
public List<V> subList(int fromIndex, int toIndex) {
refreshIfEmpty();
return wrapList(getKey(),
getListDelegate().subList(fromIndex, toIndex),
(getAncestor() == null) ? this : getAncestor());
}
/** ListIterator decorator. */
private class WrappedListIterator extends WrappedIterator
implements ListIterator<V> {
WrappedListIterator() {}
public WrappedListIterator(int index) {
super(getListDelegate().listIterator(index));
}
private ListIterator<V> getDelegateListIterator() {
return (ListIterator<V>) getDelegateIterator();
}
@Override
public boolean hasPrevious() {
return getDelegateListIterator().hasPrevious();
}
@Override
public V previous() {
return getDelegateListIterator().previous();
}
@Override
public int nextIndex() {
return getDelegateListIterator().nextIndex();
}
@Override
public int previousIndex() {
return getDelegateListIterator().previousIndex();
}
@Override
public void set(V value) {
getDelegateListIterator().set(value);
}
@Override
public void add(V value) {
boolean wasEmpty = isEmpty();
getDelegateListIterator().add(value);
totalSize++;
if (wasEmpty) {
addToMap();
}
}
}
}
/**
* List decorator that stays in sync with the multimap values for a key and
* supports rapid random access.
*/
private class RandomAccessWrappedList extends WrappedList
implements RandomAccess {
RandomAccessWrappedList(@Nullable K key, List<V> delegate,
@Nullable WrappedCollection ancestor) {
super(key, delegate, ancestor);
}
}
private transient Set<K> keySet;
@Override
public Set<K> keySet() {
Set<K> result = keySet;
return (result == null) ? keySet = createKeySet() : result;
}
private Set<K> createKeySet() {
return (map instanceof SortedMap)
? new SortedKeySet((SortedMap<K, Collection<V>>) map) : new KeySet(map);
}
private class KeySet extends Maps.KeySet<K, Collection<V>> {
/**
* This is usually the same as map, except when someone requests a
* subcollection of a {@link SortedKeySet}.
*/
final Map<K, Collection<V>> subMap;
KeySet(final Map<K, Collection<V>> subMap) {
this.subMap = subMap;
}
@Override
Map<K, Collection<V>> map() {
return subMap;
}
@Override public Iterator<K> iterator() {
return new Iterator<K>() {
final Iterator<Map.Entry<K, Collection<V>>> entryIterator
= subMap.entrySet().iterator();
Map.Entry<K, Collection<V>> entry;
@Override
public boolean hasNext() {
return entryIterator.hasNext();
}
@Override
public K next() {
entry = entryIterator.next();
return entry.getKey();
}
@Override
public void remove() {
checkState(entry != null);
Collection<V> collection = entry.getValue();
entryIterator.remove();
totalSize -= collection.size();
collection.clear();
}
};
}
// The following methods are included for better performance.
@Override public boolean remove(Object key) {
int count = 0;
Collection<V> collection = subMap.remove(key);
if (collection != null) {
count = collection.size();
collection.clear();
totalSize -= count;
}
return count > 0;
}
@Override
public void clear() {
Iterators.clear(iterator());
}
@Override public boolean containsAll(Collection<?> c) {
return subMap.keySet().containsAll(c);
}
@Override public boolean equals(@Nullable Object object) {
return this == object || this.subMap.keySet().equals(object);
}
@Override public int hashCode() {
return subMap.keySet().hashCode();
}
}
private class SortedKeySet extends KeySet implements SortedSet<K> {
SortedKeySet(SortedMap<K, Collection<V>> subMap) {
super(subMap);
}
SortedMap<K, Collection<V>> sortedMap() {
return (SortedMap<K, Collection<V>>) subMap;
}
@Override
public Comparator<? super K> comparator() {
return sortedMap().comparator();
}
@Override
public K first() {
return sortedMap().firstKey();
}
@Override
public SortedSet<K> headSet(K toElement) {
return new SortedKeySet(sortedMap().headMap(toElement));
}
@Override
public K last() {
return sortedMap().lastKey();
}
@Override
public SortedSet<K> subSet(K fromElement, K toElement) {
return new SortedKeySet(sortedMap().subMap(fromElement, toElement));
}
@Override
public SortedSet<K> tailSet(K fromElement) {
return new SortedKeySet(sortedMap().tailMap(fromElement));
}
}
private transient Multiset<K> multiset;
@Override
public Multiset<K> keys() {
Multiset<K> result = multiset;
if (result == null) {
return multiset = new Multimaps.Keys<K, V>() {
@Override Multimap<K, V> multimap() {
return AbstractMultimap.this;
}
};
}
return result;
}
/**
* Removes all values for the provided key. Unlike {@link #removeAll}, it
* returns the number of removed mappings.
*/
private int removeValuesForKey(Object key) {
Collection<V> collection;
try {
collection = map.remove(key);
} catch (NullPointerException e) {
return 0;
} catch (ClassCastException e) {
return 0;
}
int count = 0;
if (collection != null) {
count = collection.size();
collection.clear();
totalSize -= count;
}
return count;
}
private transient Collection<V> valuesCollection;
/**
* {@inheritDoc}
*
* <p>The iterator generated by the returned collection traverses the values
* for one key, followed by the values of a second key, and so on.
*/
@Override public Collection<V> values() {
Collection<V> result = valuesCollection;
if (result == null) {
return valuesCollection = new Multimaps.Values<K, V>() {
@Override Multimap<K, V> multimap() {
return AbstractMultimap.this;
}
};
}
return result;
}
private transient Collection<Map.Entry<K, V>> entries;
/*
* TODO(kevinb): should we copy this javadoc to each concrete class, so that
* classes like LinkedHashMultimap that need to say something different are
* still able to {@inheritDoc} all the way from Multimap?
*/
/**
* {@inheritDoc}
*
* <p>The iterator generated by the returned collection traverses the values
* for one key, followed by the values of a second key, and so on.
*
* <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 Collection<Map.Entry<K, V>> entries() {
Collection<Map.Entry<K, V>> result = entries;
return (result == null) ? entries = createEntries() : result;
}
Collection<Map.Entry<K, V>> createEntries() {
if (this instanceof SetMultimap) {
return new Multimaps.EntrySet<K, V>() {
@Override Multimap<K, V> multimap() {
return AbstractMultimap.this;
}
@Override public Iterator<Entry<K, V>> iterator() {
return createEntryIterator();
}
};
}
return new Multimaps.Entries<K, V>() {
@Override Multimap<K, V> multimap() {
return AbstractMultimap.this;
}
@Override public Iterator<Entry<K, V>> iterator() {
return createEntryIterator();
}
};
}
/**
* Returns an iterator across all key-value map entries, used by {@code
* entries().iterator()} and {@code values().iterator()}. The default
* behavior, which traverses the values for one key, the values for a second
* key, and so on, suffices for most {@code AbstractMultimap} implementations.
*
* @return an iterator across map entries
*/
Iterator<Map.Entry<K, V>> createEntryIterator() {
return new EntryIterator();
}
/** Iterator across all key-value pairs. */
private class EntryIterator implements Iterator<Map.Entry<K, V>> {
final Iterator<Map.Entry<K, Collection<V>>> keyIterator;
K key;
Collection<V> collection;
Iterator<V> valueIterator;
EntryIterator() {
keyIterator = map.entrySet().iterator();
if (keyIterator.hasNext()) {
findValueIteratorAndKey();
} else {
valueIterator = Iterators.emptyModifiableIterator();
}
}
void findValueIteratorAndKey() {
Map.Entry<K, Collection<V>> entry = keyIterator.next();
key = entry.getKey();
collection = entry.getValue();
valueIterator = collection.iterator();
}
@Override
public boolean hasNext() {
return keyIterator.hasNext() || valueIterator.hasNext();
}
@Override
public Map.Entry<K, V> next() {
if (!valueIterator.hasNext()) {
findValueIteratorAndKey();
}
return Maps.immutableEntry(key, valueIterator.next());
}
@Override
public void remove() {
valueIterator.remove();
if (collection.isEmpty()) {
keyIterator.remove();
}
totalSize--;
}
}
private transient Map<K, Collection<V>> asMap;
@Override
public Map<K, Collection<V>> asMap() {
Map<K, Collection<V>> result = asMap;
return (result == null) ? asMap = createAsMap() : result;
}
private Map<K, Collection<V>> createAsMap() {
return (map instanceof SortedMap)
? new SortedAsMap((SortedMap<K, Collection<V>>) map) : new AsMap(map);
}
private class AsMap extends AbstractMap<K, Collection<V>> {
/**
* Usually the same as map, but smaller for the headMap(), tailMap(), or
* subMap() of a SortedAsMap.
*/
final transient Map<K, Collection<V>> submap;
AsMap(Map<K, Collection<V>> submap) {
this.submap = submap;
}
transient Set<Map.Entry<K, Collection<V>>> entrySet;
@Override public Set<Map.Entry<K, Collection<V>>> entrySet() {
Set<Map.Entry<K, Collection<V>>> result = entrySet;
return (result == null) ? entrySet = new AsMapEntries() : result;
}
// The following methods are included for performance.
@Override public boolean containsKey(Object key) {
return Maps.safeContainsKey(submap, key);
}
@Override public Collection<V> get(Object key) {
Collection<V> collection = Maps.safeGet(submap, key);
if (collection == null) {
return null;
}
@SuppressWarnings("unchecked")
K k = (K) key;
return wrapCollection(k, collection);
}
@Override public Set<K> keySet() {
return AbstractMultimap.this.keySet();
}
@Override
public int size() {
return submap.size();
}
@Override public Collection<V> remove(Object key) {
Collection<V> collection = submap.remove(key);
if (collection == null) {
return null;
}
Collection<V> output = createCollection();
output.addAll(collection);
totalSize -= collection.size();
collection.clear();
return output;
}
@Override public boolean equals(@Nullable Object object) {
return this == object || submap.equals(object);
}
@Override public int hashCode() {
return submap.hashCode();
}
@Override public String toString() {
return submap.toString();
}
@Override
public void clear() {
if (submap == map) {
AbstractMultimap.this.clear();
} else {
Iterators.clear(new AsMapIterator());
}
}
class AsMapEntries extends Maps.EntrySet<K, Collection<V>> {
@Override
Map<K, Collection<V>> map() {
return AsMap.this;
}
@Override public Iterator<Map.Entry<K, Collection<V>>> iterator() {
return new AsMapIterator();
}
// The following methods are included for performance.
@Override public boolean contains(Object o) {
return Collections2.safeContains(submap.entrySet(), o);
}
@Override public boolean remove(Object o) {
if (!contains(o)) {
return false;
}
Map.Entry<?, ?> entry = (Map.Entry<?, ?>) o;
removeValuesForKey(entry.getKey());
return true;
}
}
/** Iterator across all keys and value collections. */
class AsMapIterator implements Iterator<Map.Entry<K, Collection<V>>> {
final Iterator<Map.Entry<K, Collection<V>>> delegateIterator
= submap.entrySet().iterator();
Collection<V> collection;
@Override
public boolean hasNext() {
return delegateIterator.hasNext();
}
@Override
public Map.Entry<K, Collection<V>> next() {
Map.Entry<K, Collection<V>> entry = delegateIterator.next();
K key = entry.getKey();
collection = entry.getValue();
return Maps.immutableEntry(key, wrapCollection(key, collection));
}
@Override
public void remove() {
delegateIterator.remove();
totalSize -= collection.size();
collection.clear();
}
}
}
private class SortedAsMap extends AsMap
implements SortedMap<K, Collection<V>> {
SortedAsMap(SortedMap<K, Collection<V>> submap) {
super(submap);
}
SortedMap<K, Collection<V>> sortedMap() {
return (SortedMap<K, Collection<V>>) submap;
}
@Override
public Comparator<? super K> comparator() {
return sortedMap().comparator();
}
@Override
public K firstKey() {
return sortedMap().firstKey();
}
@Override
public K lastKey() {
return sortedMap().lastKey();
}
@Override
public SortedMap<K, Collection<V>> headMap(K toKey) {
return new SortedAsMap(sortedMap().headMap(toKey));
}
@Override
public SortedMap<K, Collection<V>> subMap(K fromKey, K toKey) {
return new SortedAsMap(sortedMap().subMap(fromKey, toKey));
}
@Override
public SortedMap<K, Collection<V>> tailMap(K fromKey) {
return new SortedAsMap(sortedMap().tailMap(fromKey));
}
SortedSet<K> sortedKeySet;
// returns a SortedSet, even though returning a Set would be sufficient to
// satisfy the SortedMap.keySet() interface
@Override public SortedSet<K> keySet() {
SortedSet<K> result = sortedKeySet;
return (result == null)
? sortedKeySet = new SortedKeySet(sortedMap()) : result;
}
}
// Comparison and hashing
@Override public boolean equals(@Nullable Object object) {
if (object == this) {
return true;
}
if (object instanceof Multimap) {
Multimap<?, ?> that = (Multimap<?, ?>) object;
return this.map.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}.
*
* @see Map#hashCode
*/
@Override public int hashCode() {
return map.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 map.toString();
}
private static final long serialVersionUID = 2447537837011683357L;
}
| 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.GwtCompatible;
import java.util.NoSuchElementException;
import javax.annotation.Nullable;
/**
* This class provides a skeletal implementation of the {@code Iterator}
* interface for sequences whose next element can always be derived from the
* previous element. Null elements are not supported, nor is the
* {@link #remove()} method.
*
* <p>Example: <pre> {@code
*
* Iterator<Integer> powersOfTwo = new AbstractSequentialIterator<Integer>(1) {
* protected Integer computeNext(Integer previous) {
* return (previous == 1 << 30) ? null : previous * 2;
* }
* };}</pre>
*
* @author Chris Povirk
* @since 12.0 (in Guava as {@code AbstractLinkedIterator} since 8.0)
*/
@GwtCompatible
public abstract class AbstractSequentialIterator<T>
extends UnmodifiableIterator<T> {
private T nextOrNull;
/**
* Creates a new iterator with the given first element, or, if {@code
* firstOrNull} is null, creates a new empty iterator.
*/
protected AbstractSequentialIterator(@Nullable T firstOrNull) {
this.nextOrNull = firstOrNull;
}
/**
* Returns the element that follows {@code previous}, or returns {@code null}
* if no elements remain. This method is invoked during each call to
* {@link #next()} in order to compute the result of a <i>future</i> call to
* {@code next()}.
*/
protected abstract T computeNext(T previous);
@Override
public final boolean hasNext() {
return nextOrNull != null;
}
@Override
public final T next() {
if (!hasNext()) {
throw new NoSuchElementException();
}
try {
return nextOrNull;
} finally {
nextOrNull = computeNext(nextOrNull);
}
}
}
| 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 static com.google.common.base.Preconditions.checkNotNull;
import com.google.common.annotations.GwtCompatible;
import java.util.List;
import javax.annotation.Nullable;
/**
* A transforming wrapper around an ImmutableList. For internal use only. {@link
* #transform(Object)} must be functional.
*
* @author Louis Wasserman
*/
@GwtCompatible
@SuppressWarnings("serial") // uses writeReplace(), not default serialization
abstract class TransformedImmutableList<D, E> extends ImmutableList<E> {
private class TransformedView extends TransformedImmutableList<D, E> {
TransformedView(ImmutableList<D> backingList) {
super(backingList);
}
@Override E transform(D d) {
return TransformedImmutableList.this.transform(d);
}
}
private transient final ImmutableList<D> backingList;
TransformedImmutableList(ImmutableList<D> backingList) {
this.backingList = checkNotNull(backingList);
}
abstract E transform(D d);
@Override public int indexOf(@Nullable Object object) {
if (object == null) {
return -1;
}
for (int i = 0; i < size(); i++) {
if (get(i).equals(object)) {
return i;
}
}
return -1;
}
@Override public int lastIndexOf(@Nullable Object object) {
if (object == null) {
return -1;
}
for (int i = size() - 1; i >= 0; i--) {
if (get(i).equals(object)) {
return i;
}
}
return -1;
}
@Override public E get(int index) {
return transform(backingList.get(index));
}
@Override public UnmodifiableListIterator<E> listIterator(int index) {
return new AbstractIndexedListIterator<E>(size(), index) {
@Override protected E get(int index) {
return TransformedImmutableList.this.get(index);
}
};
}
@Override public int size() {
return backingList.size();
}
@Override public ImmutableList<E> subList(int fromIndex, int toIndex) {
return new TransformedView(backingList.subList(fromIndex, toIndex));
}
@Override public boolean equals(@Nullable Object obj) {
if (obj == this) {
return true;
}
if (obj instanceof List) {
List<?> list = (List<?>) obj;
return size() == list.size()
&& Iterators.elementsEqual(iterator(), list.iterator());
}
return false;
}
@Override public int hashCode() {
int hashCode = 1;
for (E e : this) {
hashCode = 31 * hashCode + (e == null ? 0 : e.hashCode());
}
return hashCode;
}
@Override public Object[] toArray() {
return ObjectArrays.toArrayImpl(this);
}
@Override public <T> T[] toArray(T[] array) {
return ObjectArrays.toArrayImpl(this, array);
}
@Override boolean isPartialView() {
return true;
}
}
| Java |
/*
* Copyright (C) 2012 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.checkState;
import static com.google.common.collect.Maps.keyOrNull;
import com.google.common.annotations.Beta;
import java.util.Iterator;
import java.util.NavigableMap;
import java.util.NavigableSet;
import java.util.NoSuchElementException;
import java.util.SortedMap;
import javax.annotation.Nullable;
/**
* A navigable map which forwards all its method calls to another navigable map. Subclasses should
* override one or more methods to modify the behavior of the backing map as desired per the <a
* href="http://en.wikipedia.org/wiki/Decorator_pattern">decorator pattern</a>.
*
* <p><i>Warning:</i> The methods of {@code ForwardingNavigableMap} forward <i>indiscriminately</i>
* to the methods of the delegate. For example, overriding {@link #put} alone <i>will not</i>
* change the behavior of {@link #putAll}, which can lead to unexpected behavior. In this case, you
* should override {@code putAll} as well, either providing your own implementation, or delegating
* to the provided {@code standardPutAll} method.
*
* <p>Each of the {@code standard} methods uses the map's comparator (or the natural ordering of
* the elements, if there is no comparator) to test element equality. As a result, if the comparator
* is not consistent with equals, some of the standard implementations may violate the {@code Map}
* contract.
*
* <p>The {@code standard} methods and the collection views they return are not guaranteed to be
* thread-safe, even when all of the methods that they depend on are thread-safe.
*
* @author Louis Wasserman
* @since 12.0
*/
@Beta
public abstract class ForwardingNavigableMap<K, V>
extends ForwardingSortedMap<K, V> implements NavigableMap<K, V> {
/** Constructor for use by subclasses. */
protected ForwardingNavigableMap() {}
@Override
protected abstract NavigableMap<K, V> delegate();
@Override
public Entry<K, V> lowerEntry(K key) {
return delegate().lowerEntry(key);
}
/**
* A sensible definition of {@link #lowerEntry} in terms of the {@code lastEntry()} of
* {@link #headMap(Object, boolean)}. If you override {@code headMap}, you may wish to override
* {@code lowerEntry} to forward to this implementation.
*/
protected Entry<K, V> standardLowerEntry(K key) {
return headMap(key, false).lastEntry();
}
@Override
public K lowerKey(K key) {
return delegate().lowerKey(key);
}
/**
* A sensible definition of {@link #lowerKey} in terms of {@code lowerEntry}. If you override
* {@link #lowerEntry}, you may wish to override {@code lowerKey} to forward to this
* implementation.
*/
protected K standardLowerKey(K key) {
return keyOrNull(lowerEntry(key));
}
@Override
public Entry<K, V> floorEntry(K key) {
return delegate().floorEntry(key);
}
/**
* A sensible definition of {@link #floorEntry} in terms of the {@code lastEntry()} of
* {@link #headMap(Object, boolean)}. If you override {@code headMap}, you may wish to override
* {@code floorEntry} to forward to this implementation.
*/
protected Entry<K, V> standardFloorEntry(K key) {
return headMap(key, true).lastEntry();
}
@Override
public K floorKey(K key) {
return delegate().floorKey(key);
}
/**
* A sensible definition of {@link #floorKey} in terms of {@code floorEntry}. If you override
* {@code floorEntry}, you may wish to override {@code floorKey} to forward to this
* implementation.
*/
protected K standardFloorKey(K key) {
return keyOrNull(floorEntry(key));
}
@Override
public Entry<K, V> ceilingEntry(K key) {
return delegate().ceilingEntry(key);
}
/**
* A sensible definition of {@link #ceilingEntry} in terms of the {@code firstEntry()} of
* {@link #tailMap(Object, boolean)}. If you override {@code tailMap}, you may wish to override
* {@code ceilingEntry} to forward to this implementation.
*/
protected Entry<K, V> standardCeilingEntry(K key) {
return tailMap(key, true).firstEntry();
}
@Override
public K ceilingKey(K key) {
return delegate().ceilingKey(key);
}
/**
* A sensible definition of {@link #ceilingKey} in terms of {@code ceilingEntry}. If you override
* {@code ceilingEntry}, you may wish to override {@code ceilingKey} to forward to this
* implementation.
*/
protected K standardCeilingKey(K key) {
return keyOrNull(ceilingEntry(key));
}
@Override
public Entry<K, V> higherEntry(K key) {
return delegate().higherEntry(key);
}
/**
* A sensible definition of {@link #higherEntry} in terms of the {@code firstEntry()} of
* {@link #tailMap(Object, boolean)}. If you override {@code tailMap}, you may wish to override
* {@code higherEntry} to forward to this implementation.
*/
protected Entry<K, V> standardHigherEntry(K key) {
return tailMap(key, false).firstEntry();
}
@Override
public K higherKey(K key) {
return delegate().higherKey(key);
}
/**
* A sensible definition of {@link #higherKey} in terms of {@code higherEntry}. If you override
* {@code higherEntry}, you may wish to override {@code higherKey} to forward to this
* implementation.
*/
protected K standardHigherKey(K key) {
return keyOrNull(higherEntry(key));
}
@Override
public Entry<K, V> firstEntry() {
return delegate().firstEntry();
}
/**
* A sensible definition of {@link #firstEntry} in terms of the {@code iterator()} of
* {@link #entrySet}. If you override {@code entrySet}, you may wish to override
* {@code firstEntry} to forward to this implementation.
*/
protected Entry<K, V> standardFirstEntry() {
return Iterables.getFirst(entrySet(), null);
}
/**
* A sensible definition of {@link #firstKey} in terms of {@code firstEntry}. If you override
* {@code firstEntry}, you may wish to override {@code firstKey} to forward to this
* implementation.
*/
protected K standardFirstKey() {
Entry<K, V> entry = firstEntry();
if (entry == null) {
throw new NoSuchElementException();
} else {
return entry.getKey();
}
}
@Override
public Entry<K, V> lastEntry() {
return delegate().lastEntry();
}
/**
* A sensible definition of {@link #lastEntry} in terms of the {@code iterator()} of the
* {@link #entrySet} of {@link #descendingMap}. If you override {@code descendingMap}, you may
* wish to override {@code lastEntry} to forward to this implementation.
*/
protected Entry<K, V> standardLastEntry() {
return Iterables.getFirst(descendingMap().entrySet(), null);
}
/**
* A sensible definition of {@link #lastKey} in terms of {@code lastEntry}. If you override
* {@code lastEntry}, you may wish to override {@code lastKey} to forward to this implementation.
*/
protected K standardLastKey() {
Entry<K, V> entry = lastEntry();
if (entry == null) {
throw new NoSuchElementException();
} else {
return entry.getKey();
}
}
@Override
public Entry<K, V> pollFirstEntry() {
return delegate().pollFirstEntry();
}
/**
* A sensible definition of {@link #pollFirstEntry} in terms of the {@code iterator} of
* {@code entrySet}. If you override {@code entrySet}, you may wish to override
* {@code pollFirstEntry} to forward to this implementation.
*/
protected Entry<K, V> standardPollFirstEntry() {
return poll(entrySet().iterator());
}
@Override
public Entry<K, V> pollLastEntry() {
return delegate().pollLastEntry();
}
/**
* A sensible definition of {@link #pollFirstEntry} in terms of the {@code iterator} of the
* {@code entrySet} of {@code descendingMap}. If you override {@code descendingMap}, you may wish
* to override {@code pollFirstEntry} to forward to this implementation.
*/
protected Entry<K, V> standardPollLastEntry() {
return poll(descendingMap().entrySet().iterator());
}
@Override
public NavigableMap<K, V> descendingMap() {
return delegate().descendingMap();
}
/**
* A sensible implementation of {@link NavigableMap#descendingMap} in terms of the methods of
* this {@code NavigableMap}. In many cases, you may wish to override
* {@link ForwardingNavigableMap#descendingMap} to forward to this implementation or a subclass
* thereof.
*
* <p>In particular, this map iterates over entries with repeated calls to
* {@link NavigableMap#lowerEntry}. If a more efficient means of iteration is available, you may
* wish to override the {@code entryIterator()} method of this class.
*
* @since 12.0
*/
@Beta
protected class StandardDescendingMap extends Maps.DescendingMap<K, V> {
/** Constructor for use by subclasses. */
public StandardDescendingMap() {}
@Override
NavigableMap<K, V> forward() {
return ForwardingNavigableMap.this;
}
@Override
protected Iterator<Entry<K, V>> entryIterator() {
return new Iterator<Entry<K, V>>() {
private Entry<K, V> toRemove = null;
private Entry<K, V> nextOrNull = forward().lastEntry();
@Override
public boolean hasNext() {
return nextOrNull != null;
}
@Override
public java.util.Map.Entry<K, V> next() {
if (!hasNext()) {
throw new NoSuchElementException();
}
try {
return nextOrNull;
} finally {
toRemove = nextOrNull;
nextOrNull = forward().lowerEntry(nextOrNull.getKey());
}
}
@Override
public void remove() {
checkState(
toRemove != null,
"Each call to remove() must be preceded by a call to next()");
forward().remove(toRemove.getKey());
toRemove = null;
}
};
}
}
@Override
public NavigableSet<K> navigableKeySet() {
return delegate().navigableKeySet();
}
/**
* A sensible implementation of {@link NavigableMap#navigableKeySet} in terms of the methods of
* this {@code NavigableMap}. In many cases, you may wish to override
* {@link ForwardingNavigableMap#navigableKeySet} to forward to this implementation or a subclass
* thereof.
*
* @since 12.0
*/
@Beta
protected class StandardNavigableKeySet extends Maps.NavigableKeySet<K, V> {
/** Constructor for use by subclasses. */
public StandardNavigableKeySet() {}
@Override
NavigableMap<K, V> map() {
return ForwardingNavigableMap.this;
}
}
@Override
public NavigableSet<K> descendingKeySet() {
return delegate().descendingKeySet();
}
/**
* A sensible definition of {@link #descendingKeySet} as the {@code navigableKeySet} of
* {@link #descendingMap}. (The {@link StandardDescendingMap} implementation implements
* {@code navigableKeySet} on its own, so as not to cause an infinite loop.) If you override
* {@code descendingMap}, you may wish to override {@code descendingKeySet} to forward to this
* implementation.
*/
protected NavigableSet<K> standardDescendingKeySet() {
return descendingMap().navigableKeySet();
}
/**
* A sensible definition of {@link #subMap(Object, Object)} in terms of
* {@link #subMap(Object, boolean, Object, boolean)}. If you override
* {@code subMap(K, boolean, K, boolean)}, you may wish to override {@code subMap} to forward to
* this implementation.
*/
@Override
protected SortedMap<K, V> standardSubMap(K fromKey, K toKey) {
return subMap(fromKey, true, toKey, false);
}
@Override
public NavigableMap<K, V> subMap(K fromKey, boolean fromInclusive, K toKey, boolean toInclusive) {
return delegate().subMap(fromKey, fromInclusive, toKey, toInclusive);
}
@Override
public NavigableMap<K, V> headMap(K toKey, boolean inclusive) {
return delegate().headMap(toKey, inclusive);
}
@Override
public NavigableMap<K, V> tailMap(K fromKey, boolean inclusive) {
return delegate().tailMap(fromKey, inclusive);
}
/**
* A sensible definition of {@link #headMap(Object)} in terms of
* {@link #headMap(Object, boolean)}. If you override {@code headMap(K, boolean)}, you may wish
* to override {@code headMap} to forward to this implementation.
*/
protected SortedMap<K, V> standardHeadMap(K toKey) {
return headMap(toKey, false);
}
/**
* A sensible definition of {@link #tailMap(Object)} in terms of
* {@link #tailMap(Object, boolean)}. If you override {@code tailMap(K, boolean)}, you may wish
* to override {@code tailMap} to forward to this implementation.
*/
protected SortedMap<K, V> standardTailMap(K fromKey) {
return tailMap(fromKey, true);
}
@Nullable
private static <T> T poll(Iterator<T> iterator) {
if (iterator.hasNext()) {
T result = iterator.next();
iterator.remove();
return result;
}
return null;
}
}
| 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 static com.google.common.base.Preconditions.checkNotNull;
import com.google.common.annotations.GwtCompatible;
import com.google.common.base.Function;
import com.google.common.collect.Multiset.Entry;
import java.util.Arrays;
import java.util.Collection;
import java.util.Collections;
import java.util.Comparator;
import java.util.Iterator;
import java.util.List;
import java.util.Set;
import java.util.SortedSet;
/**
* Utilities for dealing with sorted collections of all types.
*
* @author Louis Wasserman
*/
@GwtCompatible
final class SortedIterables {
private SortedIterables() {}
/**
* Returns {@code true} if {@code elements} is a sorted collection using an ordering equivalent
* to {@code comparator}.
*/
public static boolean hasSameComparator(Comparator<?> comparator, Iterable<?> elements) {
checkNotNull(comparator);
checkNotNull(elements);
Comparator<?> comparator2;
if (elements instanceof SortedSet) {
SortedSet<?> sortedSet = (SortedSet<?>) elements;
comparator2 = sortedSet.comparator();
if (comparator2 == null) {
comparator2 = (Comparator) Ordering.natural();
}
} else if (elements instanceof SortedIterable) {
comparator2 = ((SortedIterable<?>) elements).comparator();
} else {
comparator2 = null;
}
return comparator.equals(comparator2);
}
/**
* Returns a sorted collection of the unique elements according to the specified comparator. Does
* not check for null.
*/
@SuppressWarnings("unchecked")
public static <E> Collection<E> sortedUnique(
Comparator<? super E> comparator, Iterator<E> elements) {
SortedSet<E> sortedSet = Sets.newTreeSet(comparator);
Iterators.addAll(sortedSet, elements);
return sortedSet;
}
/**
* Returns a sorted collection of the unique elements according to the specified comparator. Does
* not check for null.
*/
@SuppressWarnings("unchecked")
public static <E> Collection<E> sortedUnique(
Comparator<? super E> comparator, Iterable<E> elements) {
if (elements instanceof Multiset) {
elements = ((Multiset<E>) elements).elementSet();
}
if (elements instanceof Set) {
if (hasSameComparator(comparator, elements)) {
return (Set<E>) elements;
}
List<E> list = Lists.newArrayList(elements);
Collections.sort(list, comparator);
return list;
}
E[] array = (E[]) Iterables.toArray(elements);
if (!hasSameComparator(comparator, elements)) {
Arrays.sort(array, comparator);
}
return uniquifySortedArray(comparator, array);
}
private static <E> Collection<E> uniquifySortedArray(
Comparator<? super E> comparator, E[] array) {
if (array.length == 0) {
return Collections.emptySet();
}
int length = 1;
for (int i = 1; i < array.length; i++) {
int cmp = comparator.compare(array[i], array[length - 1]);
if (cmp != 0) {
array[length++] = array[i];
}
}
if (length < array.length) {
array = ObjectArrays.arraysCopyOf(array, length);
}
return Arrays.asList(array);
}
/**
* Returns a collection of multiset entries representing the counts of the distinct elements, in
* sorted order. Does not check for null.
*/
public static <E> Collection<Multiset.Entry<E>> sortedCounts(
Comparator<? super E> comparator, Iterator<E> elements) {
TreeMultiset<E> multiset = TreeMultiset.create(comparator);
Iterators.addAll(multiset, elements);
return multiset.entrySet();
}
/**
* Returns a collection of multiset entries representing the counts of the distinct elements, in
* sorted order. Does not check for null.
*/
public static <E> Collection<Multiset.Entry<E>> sortedCounts(
Comparator<? super E> comparator, Iterable<E> elements) {
if (elements instanceof Multiset) {
Multiset<E> multiset = (Multiset<E>) elements;
if (hasSameComparator(comparator, elements)) {
return multiset.entrySet();
}
List<Multiset.Entry<E>> entries = Lists.newArrayList(multiset.entrySet());
Collections.sort(
entries, Ordering.from(comparator).onResultOf(new Function<Multiset.Entry<E>, E>() {
@Override
public E apply(Entry<E> entry) {
return entry.getElement();
}
}));
return entries;
} else if (elements instanceof Set) { // known distinct
Collection<E> sortedElements;
if (hasSameComparator(comparator, elements)) {
sortedElements = (Collection<E>) elements;
} else {
List<E> list = Lists.newArrayList(elements);
Collections.sort(list, comparator);
sortedElements = list;
}
return singletonEntries(sortedElements);
} else if (hasSameComparator(comparator, elements)) {
E current = null;
int currentCount = 0;
List<Multiset.Entry<E>> sortedEntries = Lists.newArrayList();
for (E e : elements) {
if (currentCount > 0) {
if (comparator.compare(current, e) == 0) {
currentCount++;
} else {
sortedEntries.add(Multisets.immutableEntry(current, currentCount));
current = e;
currentCount = 1;
}
} else {
current = e;
currentCount = 1;
}
}
if (currentCount > 0) {
sortedEntries.add(Multisets.immutableEntry(current, currentCount));
}
return sortedEntries;
}
TreeMultiset<E> multiset = TreeMultiset.create(comparator);
Iterables.addAll(multiset, elements);
return multiset.entrySet();
}
static <E> Collection<Multiset.Entry<E>> singletonEntries(Collection<E> set) {
return Collections2.transform(set, new Function<E, Multiset.Entry<E>>() {
@Override
public Entry<E> apply(E elem) {
return Multisets.immutableEntry(elem, 1);
}
});
}
}
| 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.Iterator;
import java.util.NoSuchElementException;
/**
* Static methods pertaining to {@link Range} instances. Each of the
* {@link Range nine types of ranges} can be constructed with a corresponding
* factory method:
*
* <dl>
* <dt>{@code (a..b)}
* <dd>{@link #open}
* <dt>{@code [a..b]}
* <dd>{@link #closed}
* <dt>{@code [a..b)}
* <dd>{@link #closedOpen}
* <dt>{@code (a..b]}
* <dd>{@link #openClosed}
* <dt>{@code (a..+∞)}
* <dd>{@link #greaterThan}
* <dt>{@code [a..+∞)}
* <dd>{@link #atLeast}
* <dt>{@code (-∞..b)}
* <dd>{@link #lessThan}
* <dt>{@code (-∞..b]}
* <dd>{@link #atMost}
* <dt>{@code (-∞..+∞)}
* <dd>{@link #all}
* </dl>
*
* <p>Additionally, {@link Range} instances can be constructed by passing the
* {@link BoundType bound types} explicitly.
*
* <dl>
* <dt>Bounded on both ends
* <dd>{@link #range}
* <dt>Unbounded on top ({@code (a..+∞)} or {@code (a..+∞)})
* <dd>{@link #downTo}
* <dt>Unbounded on bottom ({@code (-∞..b)} or {@code (-∞..b]})
* <dd>{@link #upTo}
* </dl>
*
* <p>See the Guava User Guide article on <a href=
* "http://code.google.com/p/guava-libraries/wiki/RangesExplained">
* {@code Range}</a>.
*
* @author Kevin Bourrillion
* @author Gregory Kick
* @since 10.0
*/
@GwtCompatible
@Beta
public final class Ranges {
private Ranges() {}
static <C extends Comparable<?>> Range<C> create(
Cut<C> lowerBound, Cut<C> upperBound) {
return new Range<C>(lowerBound, upperBound);
}
/**
* Returns a range that contains all values strictly greater than {@code
* lower} and strictly less than {@code upper}.
*
* @throws IllegalArgumentException if {@code lower} is greater than <i>or
* equal to</i> {@code upper}
*/
public static <C extends Comparable<?>> Range<C> open(C lower, C upper) {
return create(Cut.aboveValue(lower), Cut.belowValue(upper));
}
/**
* Returns a range that contains all values greater than or equal to
* {@code lower} and less than or equal to {@code upper}.
*
* @throws IllegalArgumentException if {@code lower} is greater than {@code
* upper}
*/
public static <C extends Comparable<?>> Range<C> closed(C lower, C upper) {
return create(Cut.belowValue(lower), Cut.aboveValue(upper));
}
/**
* Returns a range that contains all values greater than or equal to
* {@code lower} and strictly less than {@code upper}.
*
* @throws IllegalArgumentException if {@code lower} is greater than {@code
* upper}
*/
public static <C extends Comparable<?>> Range<C> closedOpen(
C lower, C upper) {
return create(Cut.belowValue(lower), Cut.belowValue(upper));
}
/**
* Returns a range that contains all values strictly greater than {@code
* lower} and less than or equal to {@code upper}.
*
* @throws IllegalArgumentException if {@code lower} is greater than {@code
* upper}
*/
public static <C extends Comparable<?>> Range<C> openClosed(
C lower, C upper) {
return create(Cut.aboveValue(lower), Cut.aboveValue(upper));
}
/**
* Returns a range that contains any value from {@code lower} to {@code
* upper}, where each endpoint may be either inclusive (closed) or exclusive
* (open).
*
* @throws IllegalArgumentException if {@code lower} is greater than {@code
* upper}
*/
public static <C extends Comparable<?>> Range<C> range(
C lower, BoundType lowerType, C upper, BoundType upperType) {
checkNotNull(lowerType);
checkNotNull(upperType);
Cut<C> lowerBound = (lowerType == BoundType.OPEN)
? Cut.aboveValue(lower)
: Cut.belowValue(lower);
Cut<C> upperBound = (upperType == BoundType.OPEN)
? Cut.belowValue(upper)
: Cut.aboveValue(upper);
return create(lowerBound, upperBound);
}
/**
* Returns a range that contains all values strictly less than {@code
* endpoint}.
*/
public static <C extends Comparable<?>> Range<C> lessThan(C endpoint) {
return create(Cut.<C>belowAll(), Cut.belowValue(endpoint));
}
/**
* Returns a range that contains all values less than or equal to
* {@code endpoint}.
*/
public static <C extends Comparable<?>> Range<C> atMost(C endpoint) {
return create(Cut.<C>belowAll(), Cut.aboveValue(endpoint));
}
/**
* Returns a range with no lower bound up to the given endpoint, which may be
* either inclusive (closed) or exclusive (open).
*/
public static <C extends Comparable<?>> Range<C> upTo(
C endpoint, BoundType boundType) {
switch (boundType) {
case OPEN:
return lessThan(endpoint);
case CLOSED:
return atMost(endpoint);
default:
throw new AssertionError();
}
}
/**
* Returns a range that contains all values strictly greater than {@code
* endpoint}.
*/
public static <C extends Comparable<?>> Range<C> greaterThan(C endpoint) {
return create(Cut.aboveValue(endpoint), Cut.<C>aboveAll());
}
/**
* Returns a range that contains all values greater than or equal to
* {@code endpoint}.
*/
public static <C extends Comparable<?>> Range<C> atLeast(C endpoint) {
return create(Cut.belowValue(endpoint), Cut.<C>aboveAll());
}
/**
* Returns a range from the given endpoint, which may be either inclusive
* (closed) or exclusive (open), with no upper bound.
*/
public static <C extends Comparable<?>> Range<C> downTo(
C endpoint, BoundType boundType) {
switch (boundType) {
case OPEN:
return greaterThan(endpoint);
case CLOSED:
return atLeast(endpoint);
default:
throw new AssertionError();
}
}
/** Returns a range that contains every value of type {@code C}. */
public static <C extends Comparable<?>> Range<C> all() {
return create(Cut.<C>belowAll(), Cut.<C>aboveAll());
}
/**
* Returns a range that {@linkplain Range#contains(Comparable) contains} only
* the given value. The returned range is {@linkplain BoundType#CLOSED closed}
* on both ends.
*/
public static <C extends Comparable<?>> Range<C> singleton(C value) {
return closed(value, value);
}
/**
* Returns the minimal range that
* {@linkplain Range#contains(Comparable) contains} all of the given values.
* The returned range is {@linkplain BoundType#CLOSED closed} on both ends.
*
* @throws ClassCastException if the parameters are not <i>mutually
* comparable</i>
* @throws NoSuchElementException if {@code values} is empty
* @throws NullPointerException if any of {@code values} is null
*/
public static <C extends Comparable<?>> Range<C> encloseAll(
Iterable<C> values) {
checkNotNull(values);
if (values instanceof ContiguousSet) {
return ((ContiguousSet<C>) values).range();
}
Iterator<C> valueIterator = values.iterator();
C min = checkNotNull(valueIterator.next());
C max = min;
while (valueIterator.hasNext()) {
C value = checkNotNull(valueIterator.next());
min = Ordering.natural().min(min, value);
max = Ordering.natural().max(max, value);
}
return closed(min, max);
}
}
| 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.io.Serializable;
/** An ordering that uses the reverse of the natural order of the values. */
@GwtCompatible(serializable = true)
final class UsingToStringOrdering
extends Ordering<Object> implements Serializable {
static final UsingToStringOrdering INSTANCE = new UsingToStringOrdering();
@Override public int compare(Object left, Object right) {
return left.toString().compareTo(right.toString());
}
// preserve singleton-ness, so equals() and hashCode() work correctly
private Object readResolve() {
return INSTANCE;
}
@Override public String toString() {
return "Ordering.usingToString()";
}
private UsingToStringOrdering() {}
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.collect;
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.checkPositionIndex;
import static com.google.common.base.Preconditions.checkPositionIndexes;
import static com.google.common.base.Preconditions.checkState;
import com.google.common.annotations.Beta;
import com.google.common.annotations.GwtCompatible;
import com.google.common.annotations.VisibleForTesting;
import com.google.common.base.Function;
import com.google.common.base.Objects;
import com.google.common.primitives.Ints;
import java.io.Serializable;
import java.util.AbstractList;
import java.util.AbstractSequentialList;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Collection;
import java.util.Collections;
import java.util.Iterator;
import java.util.LinkedList;
import java.util.List;
import java.util.ListIterator;
import java.util.NoSuchElementException;
import java.util.RandomAccess;
import javax.annotation.Nullable;
/**
* Static utility methods pertaining to {@link List} instances. Also see this
* class's counterparts {@link Sets} and {@link Maps}.
*
* <p>See the Guava User Guide article on <a href=
* "http://code.google.com/p/guava-libraries/wiki/CollectionUtilitiesExplained#Lists">
* {@code Lists}</a>.
*
* @author Kevin Bourrillion
* @author Mike Bostock
* @author Louis Wasserman
* @since 2.0 (imported from Google Collections Library)
*/
@GwtCompatible
public final class Lists {
private Lists() {}
// ArrayList
/**
* Creates a <i>mutable</i>, empty {@code ArrayList} instance.
*
* <p><b>Note:</b> if mutability is not required, use {@link
* ImmutableList#of()} instead.
*
* @return a new, empty {@code ArrayList}
*/
@GwtCompatible(serializable = true)
public static <E> ArrayList<E> newArrayList() {
return new ArrayList<E>();
}
/**
* Creates a <i>mutable</i> {@code ArrayList} instance containing the given
* elements.
*
* <p><b>Note:</b> if mutability is not required and the elements are
* non-null, use an overload of {@link ImmutableList#of()} (for varargs) or
* {@link ImmutableList#copyOf(Object[])} (for an array) instead.
*
* @param elements the elements that the list should contain, in order
* @return a new {@code ArrayList} containing those elements
*/
@GwtCompatible(serializable = true)
public static <E> ArrayList<E> newArrayList(E... elements) {
checkNotNull(elements); // for GWT
// Avoid integer overflow when a large array is passed in
int capacity = computeArrayListCapacity(elements.length);
ArrayList<E> list = new ArrayList<E>(capacity);
Collections.addAll(list, elements);
return list;
}
@VisibleForTesting static int computeArrayListCapacity(int arraySize) {
checkArgument(arraySize >= 0);
// TODO(kevinb): Figure out the right behavior, and document it
return Ints.saturatedCast(5L + arraySize + (arraySize / 10));
}
/**
* Creates a <i>mutable</i> {@code ArrayList} instance containing the given
* elements.
*
* <p><b>Note:</b> if mutability is not required and the elements are
* non-null, use {@link ImmutableList#copyOf(Iterator)} instead.
*
* @param elements the elements that the list should contain, in order
* @return a new {@code ArrayList} containing those elements
*/
@GwtCompatible(serializable = true)
public static <E> ArrayList<E> newArrayList(Iterable<? extends E> elements) {
checkNotNull(elements); // for GWT
// Let ArrayList's sizing logic work, if possible
return (elements instanceof Collection)
? new ArrayList<E>(Collections2.cast(elements))
: newArrayList(elements.iterator());
}
/**
* Creates a <i>mutable</i> {@code ArrayList} instance containing the given
* elements.
*
* <p><b>Note:</b> if mutability is not required and the elements are
* non-null, use {@link ImmutableList#copyOf(Iterator)} instead.
*
* @param elements the elements that the list should contain, in order
* @return a new {@code ArrayList} containing those elements
*/
@GwtCompatible(serializable = true)
public static <E> ArrayList<E> newArrayList(Iterator<? extends E> elements) {
checkNotNull(elements); // for GWT
ArrayList<E> list = newArrayList();
while (elements.hasNext()) {
list.add(elements.next());
}
return list;
}
/**
* Creates an {@code ArrayList} instance backed by an array of the
* <i>exact</i> size specified; equivalent to
* {@link ArrayList#ArrayList(int)}.
*
* <p><b>Note:</b> if you know the exact size your list will be, consider
* using a fixed-size list ({@link Arrays#asList(Object[])}) or an {@link
* ImmutableList} instead of a growable {@link ArrayList}.
*
* <p><b>Note:</b> If you have only an <i>estimate</i> of the eventual size of
* the list, consider padding this estimate by a suitable amount, or simply
* use {@link #newArrayListWithExpectedSize(int)} instead.
*
* @param initialArraySize the exact size of the initial backing array for
* the returned array list ({@code ArrayList} documentation calls this
* value the "capacity")
* @return a new, empty {@code ArrayList} which is guaranteed not to resize
* itself unless its size reaches {@code initialArraySize + 1}
* @throws IllegalArgumentException if {@code initialArraySize} is negative
*/
@GwtCompatible(serializable = true)
public static <E> ArrayList<E> newArrayListWithCapacity(
int initialArraySize) {
checkArgument(initialArraySize >= 0); // for GWT.
return new ArrayList<E>(initialArraySize);
}
/**
* Creates an {@code ArrayList} instance sized appropriately to hold an
* <i>estimated</i> number of elements without resizing. A small amount of
* padding is added in case the estimate is low.
*
* <p><b>Note:</b> If you know the <i>exact</i> number of elements the list
* will hold, or prefer to calculate your own amount of padding, refer to
* {@link #newArrayListWithCapacity(int)}.
*
* @param estimatedSize an estimate of the eventual {@link List#size()} of
* the new list
* @return a new, empty {@code ArrayList}, sized appropriately to hold the
* estimated number of elements
* @throws IllegalArgumentException if {@code estimatedSize} is negative
*/
@GwtCompatible(serializable = true)
public static <E> ArrayList<E> newArrayListWithExpectedSize(
int estimatedSize) {
return new ArrayList<E>(computeArrayListCapacity(estimatedSize));
}
// LinkedList
/**
* Creates an empty {@code LinkedList} instance.
*
* <p><b>Note:</b> if you need an immutable empty {@link List}, use
* {@link ImmutableList#of()} instead.
*
* @return a new, empty {@code LinkedList}
*/
@GwtCompatible(serializable = true)
public static <E> LinkedList<E> newLinkedList() {
return new LinkedList<E>();
}
/**
* Creates a {@code LinkedList} instance containing the given elements.
*
* @param elements the elements that the list should contain, in order
* @return a new {@code LinkedList} containing those elements
*/
@GwtCompatible(serializable = true)
public static <E> LinkedList<E> newLinkedList(
Iterable<? extends E> elements) {
LinkedList<E> list = newLinkedList();
for (E element : elements) {
list.add(element);
}
return list;
}
/**
* Returns an unmodifiable list containing the specified first element and
* backed by the specified array of additional elements. Changes to the {@code
* rest} array will be reflected in the returned list. Unlike {@link
* Arrays#asList}, the returned list is unmodifiable.
*
* <p>This is useful when a varargs method needs to use a signature such as
* {@code (Foo firstFoo, Foo... moreFoos)}, in order to avoid overload
* ambiguity or to enforce a minimum argument count.
*
* <p>The returned list is serializable and implements {@link RandomAccess}.
*
* @param first the first element
* @param rest an array of additional elements, possibly empty
* @return an unmodifiable list containing the specified elements
*/
public static <E> List<E> asList(@Nullable E first, E[] rest) {
return new OnePlusArrayList<E>(first, rest);
}
/** @see Lists#asList(Object, Object[]) */
private static class OnePlusArrayList<E> extends AbstractList<E>
implements Serializable, RandomAccess {
final E first;
final E[] rest;
OnePlusArrayList(@Nullable E first, E[] rest) {
this.first = first;
this.rest = checkNotNull(rest);
}
@Override public int size() {
return rest.length + 1;
}
@Override public E get(int index) {
// check explicitly so the IOOBE will have the right message
checkElementIndex(index, size());
return (index == 0) ? first : rest[index - 1];
}
private static final long serialVersionUID = 0;
}
/**
* Returns an unmodifiable list containing the specified first and second
* element, and backed by the specified array of additional elements. Changes
* to the {@code rest} array will be reflected in the returned list. Unlike
* {@link Arrays#asList}, the returned list is unmodifiable.
*
* <p>This is useful when a varargs method needs to use a signature such as
* {@code (Foo firstFoo, Foo secondFoo, Foo... moreFoos)}, in order to avoid
* overload ambiguity or to enforce a minimum argument count.
*
* <p>The returned list is serializable and implements {@link RandomAccess}.
*
* @param first the first element
* @param second the second element
* @param rest an array of additional elements, possibly empty
* @return an unmodifiable list containing the specified elements
*/
public static <E> List<E> asList(
@Nullable E first, @Nullable E second, E[] rest) {
return new TwoPlusArrayList<E>(first, second, rest);
}
/** @see Lists#asList(Object, Object, Object[]) */
private static class TwoPlusArrayList<E> extends AbstractList<E>
implements Serializable, RandomAccess {
final E first;
final E second;
final E[] rest;
TwoPlusArrayList(@Nullable E first, @Nullable E second, E[] rest) {
this.first = first;
this.second = second;
this.rest = checkNotNull(rest);
}
@Override public int size() {
return rest.length + 2;
}
@Override public E get(int index) {
switch (index) {
case 0:
return first;
case 1:
return second;
default:
// check explicitly so the IOOBE will have the right message
checkElementIndex(index, size());
return rest[index - 2];
}
}
private static final long serialVersionUID = 0;
}
/**
* Returns a list that applies {@code function} to each element of {@code
* fromList}. The returned list is a transformed view of {@code fromList};
* changes to {@code fromList} will be reflected in the returned list and vice
* versa.
*
* <p>Since functions are not reversible, the transform is one-way and new
* items cannot be stored in the returned list. The {@code add},
* {@code addAll} and {@code set} methods are unsupported in the returned
* list.
*
* <p>The function is applied lazily, invoked when needed. This is necessary
* for the returned list to be a view, but it means that the function will be
* applied many times for bulk operations like {@link List#contains} and
* {@link List#hashCode}. For this to perform well, {@code function} should be
* fast. To avoid lazy evaluation when the returned list doesn't need to be a
* view, copy the returned list into a new list of your choosing.
*
* <p>If {@code fromList} implements {@link RandomAccess}, so will the
* returned list. The returned list always implements {@link Serializable},
* but serialization will succeed only when {@code fromList} and
* {@code function} are serializable. The returned list is threadsafe if the
* supplied list and function are.
*
* <p>If only a {@code Collection} or {@code Iterable} input is available, use
* {@link Collections2#transform} or {@link Iterables#transform}.
*/
public static <F, T> List<T> transform(
List<F> fromList, Function<? super F, ? extends T> function) {
return (fromList instanceof RandomAccess)
? new TransformingRandomAccessList<F, T>(fromList, function)
: new TransformingSequentialList<F, T>(fromList, function);
}
/**
* Implementation of a sequential transforming list.
*
* @see Lists#transform
*/
private static class TransformingSequentialList<F, T>
extends AbstractSequentialList<T> implements Serializable {
final List<F> fromList;
final Function<? super F, ? extends T> function;
TransformingSequentialList(
List<F> fromList, Function<? super F, ? extends T> function) {
this.fromList = checkNotNull(fromList);
this.function = checkNotNull(function);
}
/**
* The default implementation inherited is based on iteration and removal of
* each element which can be overkill. That's why we forward this call
* directly to the backing list.
*/
@Override public void clear() {
fromList.clear();
}
@Override public int size() {
return fromList.size();
}
@Override public ListIterator<T> listIterator(final int index) {
final ListIterator<F> delegate = fromList.listIterator(index);
return new ListIterator<T>() {
@Override
public void add(T e) {
throw new UnsupportedOperationException();
}
@Override
public boolean hasNext() {
return delegate.hasNext();
}
@Override
public boolean hasPrevious() {
return delegate.hasPrevious();
}
@Override
public T next() {
return function.apply(delegate.next());
}
@Override
public int nextIndex() {
return delegate.nextIndex();
}
@Override
public T previous() {
return function.apply(delegate.previous());
}
@Override
public int previousIndex() {
return delegate.previousIndex();
}
@Override
public void remove() {
delegate.remove();
}
@Override
public void set(T e) {
throw new UnsupportedOperationException("not supported");
}
};
}
private static final long serialVersionUID = 0;
}
/**
* Implementation of a transforming random access list. We try to make as many
* of these methods pass-through to the source list as possible so that the
* performance characteristics of the source list and transformed list are
* similar.
*
* @see Lists#transform
*/
private static class TransformingRandomAccessList<F, T>
extends AbstractList<T> implements RandomAccess, Serializable {
final List<F> fromList;
final Function<? super F, ? extends T> function;
TransformingRandomAccessList(
List<F> fromList, Function<? super F, ? extends T> function) {
this.fromList = checkNotNull(fromList);
this.function = checkNotNull(function);
}
@Override public void clear() {
fromList.clear();
}
@Override public T get(int index) {
return function.apply(fromList.get(index));
}
@Override public boolean isEmpty() {
return fromList.isEmpty();
}
@Override public T remove(int index) {
return function.apply(fromList.remove(index));
}
@Override public int size() {
return fromList.size();
}
private static final long serialVersionUID = 0;
}
/**
* Returns consecutive {@linkplain List#subList(int, int) sublists} of a list,
* each of the same size (the final list may be smaller). For example,
* partitioning a list containing {@code [a, b, c, d, e]} with a partition
* size of 3 yields {@code [[a, b, c], [d, e]]} -- an outer list containing
* two inner lists of three and two elements, all in the original order.
*
* <p>The outer list is unmodifiable, but reflects the latest state of the
* source list. The inner lists are sublist views of the original list,
* produced on demand using {@link List#subList(int, int)}, and are subject
* to all the usual caveats about modification as explained in that API.
*
* @param list the list to return consecutive sublists of
* @param size the desired size of each sublist (the last may be
* smaller)
* @return a list of consecutive sublists
* @throws IllegalArgumentException if {@code partitionSize} is nonpositive
*/
public static <T> List<List<T>> partition(List<T> list, int size) {
checkNotNull(list);
checkArgument(size > 0);
return (list instanceof RandomAccess)
? new RandomAccessPartition<T>(list, size)
: new Partition<T>(list, size);
}
private static class Partition<T> extends AbstractList<List<T>> {
final List<T> list;
final int size;
Partition(List<T> list, int size) {
this.list = list;
this.size = size;
}
@Override public List<T> get(int index) {
int listSize = size();
checkElementIndex(index, listSize);
int start = index * size;
int end = Math.min(start + size, list.size());
return list.subList(start, end);
}
@Override public int size() {
// TODO(user): refactor to common.math.IntMath.divide
int result = list.size() / size;
if (result * size != list.size()) {
result++;
}
return result;
}
@Override public boolean isEmpty() {
return list.isEmpty();
}
}
private static class RandomAccessPartition<T> extends Partition<T>
implements RandomAccess {
RandomAccessPartition(List<T> list, int size) {
super(list, size);
}
}
/**
* Returns a view of the specified string as an immutable list of {@code
* Character} values.
*
* @since 7.0
*/
@Beta public static ImmutableList<Character> charactersOf(String string) {
return new StringAsImmutableList(checkNotNull(string));
}
@SuppressWarnings("serial") // serialized using ImmutableList serialization
private static final class StringAsImmutableList
extends ImmutableList<Character> {
private final String string;
StringAsImmutableList(String string) {
this.string = string;
}
@Override public boolean contains(@Nullable Object object) {
return indexOf(object) >= 0;
}
@Override public int indexOf(@Nullable Object object) {
return (object instanceof Character)
? string.indexOf((Character) object) : -1;
}
@Override public int lastIndexOf(@Nullable Object object) {
return (object instanceof Character)
? string.lastIndexOf((Character) object) : -1;
}
@Override public UnmodifiableListIterator<Character> listIterator(
int index) {
return new AbstractIndexedListIterator<Character>(size(), index) {
@Override protected Character get(int index) {
return string.charAt(index);
}
};
}
@Override public ImmutableList<Character> subList(
int fromIndex, int toIndex) {
return charactersOf(string.substring(fromIndex, toIndex));
}
@Override boolean isPartialView() {
return false;
}
@Override public Character get(int index) {
return string.charAt(index);
}
@Override public int size() {
return string.length();
}
@Override public boolean equals(@Nullable Object obj) {
if (!(obj instanceof List)) {
return false;
}
List<?> list = (List<?>) obj;
int n = string.length();
if (n != list.size()) {
return false;
}
Iterator<?> iterator = list.iterator();
for (int i = 0; i < n; i++) {
Object elem = iterator.next();
if (!(elem instanceof Character)
|| ((Character) elem).charValue() != string.charAt(i)) {
return false;
}
}
return true;
}
int hash = 0;
@Override public int hashCode() {
int h = hash;
if (h == 0) {
h = 1;
for (int i = 0; i < string.length(); i++) {
h = h * 31 + string.charAt(i);
}
hash = h;
}
return h;
}
}
/**
* Returns a view of the specified {@code CharSequence} as a {@code
* List<Character>}, viewing {@code sequence} as a sequence of Unicode code
* units. The view does not support any modification operations, but reflects
* any changes to the underlying character sequence.
*
* @param sequence the character sequence to view as a {@code List} of
* characters
* @return an {@code List<Character>} view of the character sequence
* @since 7.0
*/
@Beta public static List<Character> charactersOf(CharSequence sequence) {
return new CharSequenceAsList(checkNotNull(sequence));
}
private static final class CharSequenceAsList
extends AbstractList<Character> {
private final CharSequence sequence;
CharSequenceAsList(CharSequence sequence) {
this.sequence = sequence;
}
@Override public Character get(int index) {
return sequence.charAt(index);
}
@Override public boolean contains(@Nullable Object o) {
return indexOf(o) >= 0;
}
@Override public int indexOf(@Nullable Object o) {
if (o instanceof Character) {
char c = (Character) o;
for (int i = 0; i < sequence.length(); i++) {
if (sequence.charAt(i) == c) {
return i;
}
}
}
return -1;
}
@Override public int lastIndexOf(@Nullable Object o) {
if (o instanceof Character) {
char c = ((Character) o).charValue();
for (int i = sequence.length() - 1; i >= 0; i--) {
if (sequence.charAt(i) == c) {
return i;
}
}
}
return -1;
}
@Override public int size() {
return sequence.length();
}
@Override public List<Character> subList(int fromIndex, int toIndex) {
return charactersOf(sequence.subSequence(fromIndex, toIndex));
}
@Override public int hashCode() {
int hash = 1;
for (int i = 0; i < sequence.length(); i++) {
hash = hash * 31 + sequence.charAt(i);
}
return hash;
}
@Override public boolean equals(@Nullable Object o) {
if (!(o instanceof List)) {
return false;
}
List<?> list = (List<?>) o;
int n = sequence.length();
if (n != list.size()) {
return false;
}
Iterator<?> iterator = list.iterator();
for (int i = 0; i < n; i++) {
Object elem = iterator.next();
if (!(elem instanceof Character)
|| ((Character) elem).charValue() != sequence.charAt(i)) {
return false;
}
}
return true;
}
}
/**
* Returns a reversed view of the specified list. For example, {@code
* Lists.reverse(Arrays.asList(1, 2, 3))} returns a list containing {@code 3,
* 2, 1}. The returned list is backed by this list, so changes in the returned
* list are reflected in this list, and vice-versa. The returned list supports
* all of the optional list operations supported by this list.
*
* <p>The returned list is random-access if the specified list is random
* access.
*
* @since 7.0
*/
public static <T> List<T> reverse(List<T> list) {
if (list instanceof ReverseList) {
return ((ReverseList<T>) list).getForwardList();
} else if (list instanceof RandomAccess) {
return new RandomAccessReverseList<T>(list);
} else {
return new ReverseList<T>(list);
}
}
private static class ReverseList<T> extends AbstractList<T> {
private final List<T> forwardList;
ReverseList(List<T> forwardList) {
this.forwardList = checkNotNull(forwardList);
}
List<T> getForwardList() {
return forwardList;
}
private int reverseIndex(int index) {
int size = size();
checkElementIndex(index, size);
return (size - 1) - index;
}
private int reversePosition(int index) {
int size = size();
checkPositionIndex(index, size);
return size - index;
}
@Override public void add(int index, @Nullable T element) {
forwardList.add(reversePosition(index), element);
}
@Override public void clear() {
forwardList.clear();
}
@Override public T remove(int index) {
return forwardList.remove(reverseIndex(index));
}
@Override protected void removeRange(int fromIndex, int toIndex) {
subList(fromIndex, toIndex).clear();
}
@Override public T set(int index, @Nullable T element) {
return forwardList.set(reverseIndex(index), element);
}
@Override public T get(int index) {
return forwardList.get(reverseIndex(index));
}
@Override public boolean isEmpty() {
return forwardList.isEmpty();
}
@Override public int size() {
return forwardList.size();
}
@Override public boolean contains(@Nullable Object o) {
return forwardList.contains(o);
}
@Override public boolean containsAll(Collection<?> c) {
return forwardList.containsAll(c);
}
@Override public List<T> subList(int fromIndex, int toIndex) {
checkPositionIndexes(fromIndex, toIndex, size());
return reverse(forwardList.subList(
reversePosition(toIndex), reversePosition(fromIndex)));
}
@Override public int indexOf(@Nullable Object o) {
int index = forwardList.lastIndexOf(o);
return (index >= 0) ? reverseIndex(index) : -1;
}
@Override public int lastIndexOf(@Nullable Object o) {
int index = forwardList.indexOf(o);
return (index >= 0) ? reverseIndex(index) : -1;
}
@Override public Iterator<T> iterator() {
return listIterator();
}
@Override public ListIterator<T> listIterator(int index) {
int start = reversePosition(index);
final ListIterator<T> forwardIterator = forwardList.listIterator(start);
return new ListIterator<T>() {
boolean canRemove;
boolean canSet;
@Override public void add(T e) {
forwardIterator.add(e);
forwardIterator.previous();
canSet = canRemove = false;
}
@Override public boolean hasNext() {
return forwardIterator.hasPrevious();
}
@Override public boolean hasPrevious() {
return forwardIterator.hasNext();
}
@Override public T next() {
if (!hasNext()) {
throw new NoSuchElementException();
}
canSet = canRemove = true;
return forwardIterator.previous();
}
@Override public int nextIndex() {
return reversePosition(forwardIterator.nextIndex());
}
@Override public T previous() {
if (!hasPrevious()) {
throw new NoSuchElementException();
}
canSet = canRemove = true;
return forwardIterator.next();
}
@Override public int previousIndex() {
return nextIndex() - 1;
}
@Override public void remove() {
checkState(canRemove);
forwardIterator.remove();
canRemove = canSet = false;
}
@Override public void set(T e) {
checkState(canSet);
forwardIterator.set(e);
}
};
}
}
private static class RandomAccessReverseList<T> extends ReverseList<T>
implements RandomAccess {
RandomAccessReverseList(List<T> forwardList) {
super(forwardList);
}
}
/**
* An implementation of {@link List#hashCode()}.
*/
static int hashCodeImpl(List<?> list){
int hashCode = 1;
for (Object o : list) {
hashCode = 31 * hashCode + (o == null ? 0 : o.hashCode());
}
return hashCode;
}
/**
* An implementation of {@link List#equals(Object)}.
*/
static boolean equalsImpl(List<?> list, @Nullable Object object) {
if (object == checkNotNull(list)) {
return true;
}
if (!(object instanceof List)) {
return false;
}
List<?> o = (List<?>) object;
return list.size() == o.size()
&& Iterators.elementsEqual(list.iterator(), o.iterator());
}
/**
* An implementation of {@link List#addAll(int, Collection)}.
*/
static <E> boolean addAllImpl(
List<E> list, int index, Iterable<? extends E> elements) {
boolean changed = false;
ListIterator<E> listIterator = list.listIterator(index);
for (E e : elements) {
listIterator.add(e);
changed = true;
}
return changed;
}
/**
* An implementation of {@link List#indexOf(Object)}.
*/
static int indexOfImpl(List<?> list, @Nullable Object element){
ListIterator<?> listIterator = list.listIterator();
while (listIterator.hasNext()) {
if (Objects.equal(element, listIterator.next())) {
return listIterator.previousIndex();
}
}
return -1;
}
/**
* An implementation of {@link List#lastIndexOf(Object)}.
*/
static int lastIndexOfImpl(List<?> list, @Nullable Object element){
ListIterator<?> listIterator = list.listIterator(list.size());
while (listIterator.hasPrevious()) {
if (Objects.equal(element, listIterator.previous())) {
return listIterator.nextIndex();
}
}
return -1;
}
/**
* Returns an implementation of {@link List#listIterator(int)}.
*/
static <E> ListIterator<E> listIteratorImpl(List<E> list, int index) {
return new AbstractListWrapper<E>(list).listIterator(index);
}
/**
* An implementation of {@link List#subList(int, int)}.
*/
static <E> List<E> subListImpl(
final List<E> list, int fromIndex, int toIndex) {
List<E> wrapper;
if (list instanceof RandomAccess) {
wrapper = new RandomAccessListWrapper<E>(list) {
@Override public ListIterator<E> listIterator(int index) {
return backingList.listIterator(index);
}
private static final long serialVersionUID = 0;
};
} else {
wrapper = new AbstractListWrapper<E>(list) {
@Override public ListIterator<E> listIterator(int index) {
return backingList.listIterator(index);
}
private static final long serialVersionUID = 0;
};
}
return wrapper.subList(fromIndex, toIndex);
}
private static class AbstractListWrapper<E> extends AbstractList<E> {
final List<E> backingList;
AbstractListWrapper(List<E> backingList) {
this.backingList = checkNotNull(backingList);
}
@Override public void add(int index, E element) {
backingList.add(index, element);
}
@Override public boolean addAll(int index, Collection<? extends E> c) {
return backingList.addAll(index, c);
}
@Override public E get(int index) {
return backingList.get(index);
}
@Override public E remove(int index) {
return backingList.remove(index);
}
@Override public E set(int index, E element) {
return backingList.set(index, element);
}
@Override public boolean contains(Object o) {
return backingList.contains(o);
}
@Override public int size() {
return backingList.size();
}
}
private static class RandomAccessListWrapper<E>
extends AbstractListWrapper<E> implements RandomAccess {
RandomAccessListWrapper(List<E> backingList) {
super(backingList);
}
}
}
| 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.GwtIncompatible;
import java.io.IOException;
import java.io.ObjectInputStream;
import java.io.ObjectOutputStream;
import java.util.EnumMap;
import java.util.Iterator;
/**
* Multiset implementation backed by an {@link EnumMap}.
*
* <p>See the Guava User Guide article on <a href=
* "http://code.google.com/p/guava-libraries/wiki/NewCollectionTypesExplained#Multiset">
* {@code Multiset}</a>.
*
* @author Jared Levy
* @since 2.0 (imported from Google Collections Library)
*/
@GwtCompatible(emulated = true)
public final class EnumMultiset<E extends Enum<E>> extends AbstractMapBasedMultiset<E> {
/** Creates an empty {@code EnumMultiset}. */
public static <E extends Enum<E>> EnumMultiset<E> create(Class<E> type) {
return new EnumMultiset<E>(type);
}
/**
* Creates a new {@code EnumMultiset} 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
* @throws IllegalArgumentException if {@code elements} is empty
*/
public static <E extends Enum<E>> EnumMultiset<E> create(Iterable<E> elements) {
Iterator<E> iterator = elements.iterator();
checkArgument(iterator.hasNext(), "EnumMultiset constructor passed empty Iterable");
EnumMultiset<E> multiset = new EnumMultiset<E>(iterator.next().getDeclaringClass());
Iterables.addAll(multiset, elements);
return multiset;
}
private transient Class<E> type;
/** Creates an empty {@code EnumMultiset}. */
private EnumMultiset(Class<E> type) {
super(WellBehavedMap.wrap(new EnumMap<E, Count>(type)));
this.type = type;
}
@GwtIncompatible("java.io.ObjectOutputStream")
private void writeObject(ObjectOutputStream stream) throws IOException {
stream.defaultWriteObject();
stream.writeObject(type);
Serialization.writeMultiset(this, stream);
}
/**
* @serialData the {@code Class<E>} for the enum type, the number of distinct
* elements, the first element, its count, the second element, its
* count, and so on
*/
@GwtIncompatible("java.io.ObjectInputStream")
private void readObject(ObjectInputStream stream) throws IOException, ClassNotFoundException {
stream.defaultReadObject();
@SuppressWarnings("unchecked") // reading data stored by writeObject
Class<E> localType = (Class<E>) stream.readObject();
type = localType;
setBackingMap(WellBehavedMap.wrap(new EnumMap<E, Count>(type)));
Serialization.populateMultiset(this, stream);
}
@GwtIncompatible("Not needed in emulated source")
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.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.Supplier;
import com.google.common.collect.Collections2.TransformedCollection;
import com.google.common.collect.Table.Cell;
import java.io.Serializable;
import java.util.Collection;
import java.util.Collections;
import java.util.Map;
import java.util.Set;
import java.util.SortedMap;
import java.util.SortedSet;
import javax.annotation.Nullable;
/**
* Provides static methods that involve a {@code Table}.
*
* <p>See the Guava User Guide article on <a href=
* "http://code.google.com/p/guava-libraries/wiki/CollectionUtilitiesExplained#Tables">
* {@code Tables}</a>.
*
* @author Jared Levy
* @author Louis Wasserman
* @since 7.0
*/
@GwtCompatible
@Beta
public final class Tables {
private Tables() {}
/**
* Returns an immutable cell with the specified row key, column key, and
* value.
*
* <p>The returned cell is serializable.
*
* @param rowKey the row key to be associated with the returned cell
* @param columnKey the column key to be associated with the returned cell
* @param value the value to be associated with the returned cell
*/
public static <R, C, V> Cell<R, C, V> immutableCell(
@Nullable R rowKey, @Nullable C columnKey, @Nullable V value) {
return new ImmutableCell<R, C, V>(rowKey, columnKey, value);
}
static final class ImmutableCell<R, C, V>
extends AbstractCell<R, C, V> implements Serializable {
private final R rowKey;
private final C columnKey;
private final V value;
ImmutableCell(
@Nullable R rowKey, @Nullable C columnKey, @Nullable V value) {
this.rowKey = rowKey;
this.columnKey = columnKey;
this.value = value;
}
@Override
public R getRowKey() {
return rowKey;
}
@Override
public C getColumnKey() {
return columnKey;
}
@Override
public V getValue() {
return value;
}
private static final long serialVersionUID = 0;
}
abstract static class AbstractCell<R, C, V> implements Cell<R, C, V> {
// needed for serialization
AbstractCell() {}
@Override public boolean equals(Object obj) {
if (obj == this) {
return true;
}
if (obj instanceof Cell) {
Cell<?, ?, ?> other = (Cell<?, ?, ?>) obj;
return Objects.equal(getRowKey(), other.getRowKey())
&& Objects.equal(getColumnKey(), other.getColumnKey())
&& Objects.equal(getValue(), other.getValue());
}
return false;
}
@Override public int hashCode() {
return Objects.hashCode(getRowKey(), getColumnKey(), getValue());
}
@Override public String toString() {
return "(" + getRowKey() + "," + getColumnKey() + ")=" + getValue();
}
}
/**
* Creates a transposed view of a given table that flips its row and column
* keys. In other words, calling {@code get(columnKey, rowKey)} on the
* generated table always returns the same value as calling {@code
* get(rowKey, columnKey)} on the original table. Updating the original table
* changes the contents of the transposed table and vice versa.
*
* <p>The returned table supports update operations as long as the input table
* supports the analogous operation with swapped rows and columns. For
* example, in a {@link HashBasedTable} instance, {@code
* rowKeySet().iterator()} supports {@code remove()} but {@code
* columnKeySet().iterator()} doesn't. With a transposed {@link
* HashBasedTable}, it's the other way around.
*/
public static <R, C, V> Table<C, R, V> transpose(Table<R, C, V> table) {
return (table instanceof TransposeTable)
? ((TransposeTable<R, C, V>) table).original
: new TransposeTable<C, R, V>(table);
}
private static class TransposeTable<C, R, V> implements Table<C, R, V> {
final Table<R, C, V> original;
TransposeTable(Table<R, C, V> original) {
this.original = checkNotNull(original);
}
@Override
public void clear() {
original.clear();
}
@Override
public Map<C, V> column(R columnKey) {
return original.row(columnKey);
}
@Override
public Set<R> columnKeySet() {
return original.rowKeySet();
}
@Override
public Map<R, Map<C, V>> columnMap() {
return original.rowMap();
}
@Override
public boolean contains(
@Nullable Object rowKey, @Nullable Object columnKey) {
return original.contains(columnKey, rowKey);
}
@Override
public boolean containsColumn(@Nullable Object columnKey) {
return original.containsRow(columnKey);
}
@Override
public boolean containsRow(@Nullable Object rowKey) {
return original.containsColumn(rowKey);
}
@Override
public boolean containsValue(@Nullable Object value) {
return original.containsValue(value);
}
@Override
public V get(@Nullable Object rowKey, @Nullable Object columnKey) {
return original.get(columnKey, rowKey);
}
@Override
public boolean isEmpty() {
return original.isEmpty();
}
@Override
public V put(C rowKey, R columnKey, V value) {
return original.put(columnKey, rowKey, value);
}
@Override
public void putAll(Table<? extends C, ? extends R, ? extends V> table) {
original.putAll(transpose(table));
}
@Override
public V remove(@Nullable Object rowKey, @Nullable Object columnKey) {
return original.remove(columnKey, rowKey);
}
@Override
public Map<R, V> row(C rowKey) {
return original.column(rowKey);
}
@Override
public Set<C> rowKeySet() {
return original.columnKeySet();
}
@Override
public Map<C, Map<R, V>> rowMap() {
return original.columnMap();
}
@Override
public int size() {
return original.size();
}
@Override
public Collection<V> values() {
return original.values();
}
@Override public boolean equals(@Nullable Object obj) {
if (obj == this) {
return true;
}
if (obj instanceof Table) {
Table<?, ?, ?> other = (Table<?, ?, ?>) obj;
return cellSet().equals(other.cellSet());
}
return false;
}
@Override public int hashCode() {
return cellSet().hashCode();
}
@Override public String toString() {
return rowMap().toString();
}
// Will cast TRANSPOSE_CELL to a type that always succeeds
private static final Function<Cell<?, ?, ?>, Cell<?, ?, ?>> TRANSPOSE_CELL =
new Function<Cell<?, ?, ?>, Cell<?, ?, ?>>() {
@Override
public Cell<?, ?, ?> apply(Cell<?, ?, ?> cell) {
return immutableCell(
cell.getColumnKey(), cell.getRowKey(), cell.getValue());
}
};
CellSet cellSet;
@Override
public Set<Cell<C, R, V>> cellSet() {
CellSet result = cellSet;
return (result == null) ? cellSet = new CellSet() : result;
}
class CellSet extends TransformedCollection<Cell<R, C, V>, Cell<C, R, V>>
implements Set<Cell<C, R, V>> {
// Casting TRANSPOSE_CELL to a type that always succeeds
@SuppressWarnings("unchecked")
CellSet() {
super(original.cellSet(), (Function) TRANSPOSE_CELL);
}
@Override public boolean equals(Object obj) {
if (obj == this) {
return true;
}
if (!(obj instanceof Set)) {
return false;
}
Set<?> os = (Set<?>) obj;
if (os.size() != size()) {
return false;
}
return containsAll(os);
}
@Override public int hashCode() {
return Sets.hashCodeImpl(this);
}
@Override public boolean contains(Object obj) {
if (obj instanceof Cell) {
Cell<?, ?, ?> cell = (Cell<?, ?, ?>) obj;
return original.cellSet().contains(immutableCell(
cell.getColumnKey(), cell.getRowKey(), cell.getValue()));
}
return false;
}
@Override public boolean remove(Object obj) {
if (obj instanceof Cell) {
Cell<?, ?, ?> cell = (Cell<?, ?, ?>) obj;
return original.cellSet().remove(immutableCell(
cell.getColumnKey(), cell.getRowKey(), cell.getValue()));
}
return false;
}
}
}
/**
* Creates a table that uses the specified backing map and factory. It can
* generate a table based on arbitrary {@link Map} classes.
*
* <p>The {@code factory}-generated and {@code backingMap} classes determine
* the table iteration order. However, the table's {@code row()} method
* returns instances of a different class than {@code factory.get()} does.
*
* <p>Call this method only when the simpler factory methods in classes like
* {@link HashBasedTable} and {@link TreeBasedTable} won't suffice.
*
* <p>The views returned by the {@code Table} methods {@link Table#column},
* {@link Table#columnKeySet}, and {@link Table#columnMap} have iterators that
* don't support {@code remove()}. Otherwise, all optional operations are
* supported. Null row keys, columns keys, and values are not supported.
*
* <p>Lookups by row key are often faster than lookups by column key, because
* the data is stored in a {@code Map<R, Map<C, V>>}. A method call like
* {@code column(columnKey).get(rowKey)} still runs quickly, since the row key
* is provided. However, {@code column(columnKey).size()} takes longer, since
* an iteration across all row keys occurs.
*
* <p>Note that this implementation is not synchronized. If multiple threads
* access this table concurrently and one of the threads modifies the table,
* it must be synchronized externally.
*
* <p>The table is serializable if {@code backingMap}, {@code factory}, the
* maps generated by {@code factory}, and the table contents are all
* serializable.
*
* <p>Note: the table assumes complete ownership over of {@code backingMap}
* and the maps returned by {@code factory}. Those objects should not be
* manually updated and they should not use soft, weak, or phantom references.
*
* @param backingMap place to store the mapping from each row key to its
* corresponding column key / value map
* @param factory supplier of new, empty maps that will each hold all column
* key / value mappings for a given row key
* @throws IllegalArgumentException if {@code backingMap} is not empty
* @since 10.0
*/
public static <R, C, V> Table<R, C, V> newCustomTable(
Map<R, Map<C, V>> backingMap, Supplier<? extends Map<C, V>> factory) {
checkArgument(backingMap.isEmpty());
checkNotNull(factory);
// TODO(jlevy): Wrap factory to validate that the supplied maps are empty?
return new StandardTable<R, C, V>(backingMap, factory);
}
/**
* Returns a view of a table where each value is transformed by a function.
* All other properties of the table, such as iteration order, are left
* intact.
*
* <p>Changes in the underlying table are reflected in this view. Conversely,
* this view supports removal operations, and these are reflected in the
* underlying table.
*
* <p>It's acceptable for the underlying table to contain null keys, and even
* null values provided that the function is capable of accepting null input.
* The transformed table might contain null values, if the function sometimes
* gives a null result.
*
* <p>The returned table is not thread-safe or serializable, even if the
* underlying table is.
*
* <p>The function is applied lazily, invoked when needed. This is necessary
* for the returned table to be a view, but it means that the function will be
* applied many times for bulk operations like {@link Table#containsValue} and
* {@code Table.toString()}. For this to perform well, {@code function} should
* be fast. To avoid lazy evaluation when the returned table doesn't need to
* be a view, copy the returned table into a new table of your choosing.
*
* @since 10.0
*/
public static <R, C, V1, V2> Table<R, C, V2> transformValues(
Table<R, C, V1> fromTable, Function<? super V1, V2> function) {
return new TransformedTable<R, C, V1, V2>(fromTable, function);
}
private static class TransformedTable<R, C, V1, V2>
implements Table<R, C, V2> {
final Table<R, C, V1> fromTable;
final Function<? super V1, V2> function;
TransformedTable(
Table<R, C, V1> fromTable, Function<? super V1, V2> function) {
this.fromTable = checkNotNull(fromTable);
this.function = checkNotNull(function);
}
@Override public boolean contains(Object rowKey, Object columnKey) {
return fromTable.contains(rowKey, columnKey);
}
@Override public boolean containsRow(Object rowKey) {
return fromTable.containsRow(rowKey);
}
@Override public boolean containsColumn(Object columnKey) {
return fromTable.containsColumn(columnKey);
}
@Override public boolean containsValue(Object value) {
return values().contains(value);
}
@Override public V2 get(Object rowKey, Object columnKey) {
// The function is passed a null input only when the table contains a null
// value.
return contains(rowKey, columnKey)
? function.apply(fromTable.get(rowKey, columnKey)) : null;
}
@Override public boolean isEmpty() {
return fromTable.isEmpty();
}
@Override public int size() {
return fromTable.size();
}
@Override public void clear() {
fromTable.clear();
}
@Override public V2 put(R rowKey, C columnKey, V2 value) {
throw new UnsupportedOperationException();
}
@Override public void putAll(
Table<? extends R, ? extends C, ? extends V2> table) {
throw new UnsupportedOperationException();
}
@Override public V2 remove(Object rowKey, Object columnKey) {
return contains(rowKey, columnKey)
? function.apply(fromTable.remove(rowKey, columnKey)) : null;
}
@Override public Map<C, V2> row(R rowKey) {
return Maps.transformValues(fromTable.row(rowKey), function);
}
@Override public Map<R, V2> column(C columnKey) {
return Maps.transformValues(fromTable.column(columnKey), function);
}
Function<Cell<R, C, V1>, Cell<R, C, V2>> cellFunction() {
return new Function<Cell<R, C, V1>, Cell<R, C, V2>>() {
@Override public Cell<R, C, V2> apply(Cell<R, C, V1> cell) {
return immutableCell(
cell.getRowKey(), cell.getColumnKey(),
function.apply(cell.getValue()));
}
};
}
class CellSet extends TransformedCollection<Cell<R, C, V1>, Cell<R, C, V2>>
implements Set<Cell<R, C, V2>> {
CellSet() {
super(fromTable.cellSet(), cellFunction());
}
@Override public boolean equals(Object obj) {
return Sets.equalsImpl(this, obj);
}
@Override public int hashCode() {
return Sets.hashCodeImpl(this);
}
@Override public boolean contains(Object obj) {
if (obj instanceof Cell) {
Cell<?, ?, ?> cell = (Cell<?, ?, ?>) obj;
if (!Objects.equal(
cell.getValue(), get(cell.getRowKey(), cell.getColumnKey()))) {
return false;
}
return cell.getValue() != null
|| fromTable.contains(cell.getRowKey(), cell.getColumnKey());
}
return false;
}
@Override public boolean remove(Object obj) {
if (contains(obj)) {
Cell<?, ?, ?> cell = (Cell<?, ?, ?>) obj;
fromTable.remove(cell.getRowKey(), cell.getColumnKey());
return true;
}
return false;
}
}
CellSet cellSet;
@Override public Set<Cell<R, C, V2>> cellSet() {
return (cellSet == null) ? cellSet = new CellSet() : cellSet;
}
@Override public Set<R> rowKeySet() {
return fromTable.rowKeySet();
}
@Override public Set<C> columnKeySet() {
return fromTable.columnKeySet();
}
Collection<V2> values;
@Override public Collection<V2> values() {
return (values == null)
? values = Collections2.transform(fromTable.values(), function)
: values;
}
Map<R, Map<C, V2>> createRowMap() {
Function<Map<C, V1>, Map<C, V2>> rowFunction =
new Function<Map<C, V1>, Map<C, V2>>() {
@Override public Map<C, V2> apply(Map<C, V1> row) {
return Maps.transformValues(row, function);
}
};
return Maps.transformValues(fromTable.rowMap(), rowFunction);
}
Map<R, Map<C, V2>> rowMap;
@Override public Map<R, Map<C, V2>> rowMap() {
return (rowMap == null) ? rowMap = createRowMap() : rowMap;
}
Map<C, Map<R, V2>> createColumnMap() {
Function<Map<R, V1>, Map<R, V2>> columnFunction =
new Function<Map<R, V1>, Map<R, V2>>() {
@Override public Map<R, V2> apply(Map<R, V1> column) {
return Maps.transformValues(column, function);
}
};
return Maps.transformValues(fromTable.columnMap(), columnFunction);
}
Map<C, Map<R, V2>> columnMap;
@Override public Map<C, Map<R, V2>> columnMap() {
return (columnMap == null) ? columnMap = createColumnMap() : columnMap;
}
@Override public boolean equals(@Nullable Object obj) {
if (obj == this) {
return true;
}
if (obj instanceof Table) {
Table<?, ?, ?> other = (Table<?, ?, ?>) obj;
return cellSet().equals(other.cellSet());
}
return false;
}
@Override public int hashCode() {
return cellSet().hashCode();
}
@Override public String toString() {
return rowMap().toString();
}
}
/**
* Returns an unmodifiable view of the specified table. This method allows modules to provide
* users with "read-only" access to internal tables. Query operations on the returned table
* "read through" to the specified table, and attempts to modify the returned table, whether
* direct or via its collection views, result in an {@code UnsupportedOperationException}.
*
* <p>The returned table will be serializable if the specified table is serializable.
*
* <p>Consider using an {@link ImmutableTable}, which is guaranteed never to change.
*
* @param table
* the table for which an unmodifiable view is to be returned
* @return an unmodifiable view of the specified table
* @since 11.0
*/
public static <R, C, V> Table<R, C, V> unmodifiableTable(
Table<? extends R, ? extends C, ? extends V> table) {
return new UnmodifiableTable<R, C, V>(table);
}
private static class UnmodifiableTable<R, C, V>
extends ForwardingTable<R, C, V> implements Serializable {
final Table<? extends R, ? extends C, ? extends V> delegate;
UnmodifiableTable(Table<? extends R, ? extends C, ? extends V> delegate) {
this.delegate = checkNotNull(delegate);
}
@SuppressWarnings("unchecked") // safe, covariant cast
@Override
protected Table<R, C, V> delegate() {
return (Table<R, C, V>) delegate;
}
@Override
public Set<Cell<R, C, V>> cellSet() {
return Collections.unmodifiableSet(super.cellSet());
}
@Override
public void clear() {
throw new UnsupportedOperationException();
}
@Override
public Map<R, V> column(@Nullable C columnKey) {
return Collections.unmodifiableMap(super.column(columnKey));
}
@Override
public Set<C> columnKeySet() {
return Collections.unmodifiableSet(super.columnKeySet());
}
@Override
public Map<C, Map<R, V>> columnMap() {
Function<Map<R, V>, Map<R, V>> wrapper = unmodifiableWrapper();
return Collections.unmodifiableMap(Maps.transformValues(super.columnMap(), wrapper));
}
@Override
public V put(@Nullable R rowKey, @Nullable C columnKey, @Nullable V value) {
throw new UnsupportedOperationException();
}
@Override
public void putAll(Table<? extends R, ? extends C, ? extends V> table) {
throw new UnsupportedOperationException();
}
@Override
public V remove(@Nullable Object rowKey, @Nullable Object columnKey) {
throw new UnsupportedOperationException();
}
@Override
public Map<C, V> row(@Nullable R rowKey) {
return Collections.unmodifiableMap(super.row(rowKey));
}
@Override
public Set<R> rowKeySet() {
return Collections.unmodifiableSet(super.rowKeySet());
}
@Override
public Map<R, Map<C, V>> rowMap() {
Function<Map<C, V>, Map<C, V>> wrapper = unmodifiableWrapper();
return Collections.unmodifiableMap(Maps.transformValues(super.rowMap(), wrapper));
}
@Override
public Collection<V> values() {
return Collections.unmodifiableCollection(super.values());
}
private static final long serialVersionUID = 0;
}
/**
* Returns an unmodifiable view of the specified row-sorted table. This method allows modules to
* provide users with "read-only" access to internal tables. Query operations on the returned
* table "read through" to the specified table, and attemps to modify the returned table, whether
* direct or via its collection views, result in an {@code UnsupportedOperationException}.
*
* <p>The returned table will be serializable if the specified table is serializable.
*
* @param table the row-sorted table for which an unmodifiable view is to be returned
* @return an unmodifiable view of the specified table
* @since 11.0
*/
public static <R, C, V> RowSortedTable<R, C, V> unmodifiableRowSortedTable(
RowSortedTable<R, ? extends C, ? extends V> table) {
/*
* It's not ? extends R, because it's technically not covariant in R. Specifically,
* table.rowMap().comparator() could return a comparator that only works for the ? extends R.
* Collections.unmodifiableSortedMap makes the same distinction.
*/
return new UnmodifiableRowSortedMap<R, C, V>(table);
}
static final class UnmodifiableRowSortedMap<R, C, V> extends UnmodifiableTable<R, C, V>
implements RowSortedTable<R, C, V> {
public UnmodifiableRowSortedMap(RowSortedTable<R, ? extends C, ? extends V> delegate) {
super(delegate);
}
@Override
protected RowSortedTable<R, C, V> delegate() {
return (RowSortedTable<R, C, V>) super.delegate();
}
@Override
public SortedMap<R, Map<C, V>> rowMap() {
Function<Map<C, V>, Map<C, V>> wrapper = unmodifiableWrapper();
return Collections.unmodifiableSortedMap(Maps.transformValues(delegate().rowMap(), wrapper));
}
@Override
public SortedSet<R> rowKeySet() {
return Collections.unmodifiableSortedSet(delegate().rowKeySet());
}
private static final long serialVersionUID = 0;
}
@SuppressWarnings("unchecked")
private static <K, V> Function<Map<K, V>, Map<K, V>> unmodifiableWrapper() {
return (Function) UNMODIFIABLE_WRAPPER;
}
private static final Function<? extends Map<?, ?>, ? extends Map<?, ?>> UNMODIFIABLE_WRAPPER =
new Function<Map<Object, Object>, Map<Object, Object>>() {
@Override
public Map<Object, Object> apply(Map<Object, Object> input) {
return Collections.unmodifiableMap(input);
}
};
}
| 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.annotations.GwtCompatible;
/**
* "Overrides" the {@link ImmutableSet} static methods that lack
* {@link ImmutableSortedSet} equivalents with deprecated, exception-throwing
* versions. This prevents accidents like the following: <pre> {@code
*
* List<Object> objects = ...;
* // Sort them:
* Set<Object> sorted = ImmutableSortedSet.copyOf(objects);
* // BAD CODE! The returned set is actually an unsorted ImmutableSet!}</pre>
*
* While we could put the overrides in {@link ImmutableSortedSet} itself, it
* seems clearer to separate these "do not call" methods from those intended for
* normal use.
*
* @author Chris Povirk
*/
@GwtCompatible
abstract class ImmutableSortedSetFauxverideShim<E> extends ImmutableSet<E> {
/**
* Not supported. Use {@link ImmutableSortedSet#naturalOrder}, which offers
* better type-safety, instead. This method exists only to hide
* {@link ImmutableSet#builder} from consumers of {@code ImmutableSortedSet}.
*
* @throws UnsupportedOperationException always
* @deprecated Use {@link ImmutableSortedSet#naturalOrder}, which offers
* better type-safety.
*/
@Deprecated public static <E> ImmutableSortedSet.Builder<E> builder() {
throw new UnsupportedOperationException();
}
/**
* Not supported. <b>You are attempting to create a set that may contain a
* non-{@code Comparable} element.</b> Proper calls will resolve to the
* version in {@code ImmutableSortedSet}, not this dummy version.
*
* @throws UnsupportedOperationException always
* @deprecated <b>Pass a parameter of type {@code Comparable} to use {@link
* ImmutableSortedSet#of(Comparable)}.</b>
*/
@Deprecated public static <E> ImmutableSortedSet<E> of(E element) {
throw new UnsupportedOperationException();
}
/**
* Not supported. <b>You are attempting to create a set that may contain a
* non-{@code Comparable} element.</b> Proper calls will resolve to the
* version in {@code ImmutableSortedSet}, not this dummy version.
*
* @throws UnsupportedOperationException always
* @deprecated <b>Pass the parameters of type {@code Comparable} to use {@link
* ImmutableSortedSet#of(Comparable, Comparable)}.</b>
*/
@Deprecated public static <E> ImmutableSortedSet<E> of(E e1, E e2) {
throw new UnsupportedOperationException();
}
/**
* Not supported. <b>You are attempting to create a set that may contain a
* non-{@code Comparable} element.</b> Proper calls will resolve to the
* version in {@code ImmutableSortedSet}, not this dummy version.
*
* @throws UnsupportedOperationException always
* @deprecated <b>Pass the parameters of type {@code Comparable} to use {@link
* ImmutableSortedSet#of(Comparable, Comparable, Comparable)}.</b>
*/
@Deprecated public static <E> ImmutableSortedSet<E> of(E e1, E e2, E e3) {
throw new UnsupportedOperationException();
}
/**
* Not supported. <b>You are attempting to create a set that may contain a
* non-{@code Comparable} element.</b> Proper calls will resolve to the
* version in {@code ImmutableSortedSet}, not this dummy version.
*
* @throws UnsupportedOperationException always
* @deprecated <b>Pass the parameters of type {@code Comparable} to use {@link
* ImmutableSortedSet#of(Comparable, Comparable, Comparable, Comparable)}.
* </b>
*/
@Deprecated public static <E> ImmutableSortedSet<E> of(
E e1, E e2, E e3, E e4) {
throw new UnsupportedOperationException();
}
/**
* Not supported. <b>You are attempting to create a set that may contain a
* non-{@code Comparable} element.</b> Proper calls will resolve to the
* version in {@code ImmutableSortedSet}, not this dummy version.
*
* @throws UnsupportedOperationException always
* @deprecated <b>Pass the parameters of type {@code Comparable} to use {@link
* ImmutableSortedSet#of(
* Comparable, Comparable, Comparable, Comparable, Comparable)}. </b>
*/
@Deprecated public static <E> ImmutableSortedSet<E> of(
E e1, E e2, E e3, E e4, E e5) {
throw new UnsupportedOperationException();
}
/**
* Not supported. <b>You are attempting to create a set that may contain a
* non-{@code Comparable} element.</b> Proper calls will resolve to the
* version in {@code ImmutableSortedSet}, not this dummy version.
*
* @throws UnsupportedOperationException always
* @deprecated <b>Pass the parameters of type {@code Comparable} to use {@link
* ImmutableSortedSet#of(Comparable, Comparable, Comparable, Comparable,
* Comparable, Comparable, Comparable...)}. </b>
*/
@Deprecated public static <E> ImmutableSortedSet<E> of(
E e1, E e2, E e3, E e4, E e5, E e6, E... remaining) {
throw new UnsupportedOperationException();
}
/**
* Not supported. <b>You are attempting to create a set that may contain
* non-{@code Comparable} elements.</b> Proper calls will resolve to the
* version in {@code ImmutableSortedSet}, not this dummy version.
*
* @throws UnsupportedOperationException always
* @deprecated <b>Pass parameters of type {@code Comparable} to use {@link
* ImmutableSortedSet#copyOf(Comparable[])}.</b>
*/
@Deprecated public static <E> ImmutableSortedSet<E> copyOf(E[] elements) {
throw new UnsupportedOperationException();
}
/*
* We would like to include an unsupported "<E> copyOf(Iterable<E>)" here,
* providing only the properly typed
* "<E extends Comparable<E>> copyOf(Iterable<E>)" in ImmutableSortedSet (and
* likewise for the Iterator equivalent). However, due to a change in Sun's
* interpretation of the JLS (as described at
* http://bugs.sun.com/view_bug.do?bug_id=6182950), the OpenJDK 7 compiler
* available as of this writing rejects our attempts. To maintain
* compatibility with that version and with any other compilers that interpret
* the JLS similarly, there is no definition of copyOf() here, and the
* definition in ImmutableSortedSet matches that in ImmutableSet.
*
* The result is that ImmutableSortedSet.copyOf() may be called on
* non-Comparable elements. We have not discovered a better solution. In
* retrospect, the static factory methods should have gone in a separate class
* so that ImmutableSortedSet wouldn't "inherit" too-permissive factory
* methods from ImmutableSet.
*/
}
| 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.Beta;
import com.google.common.annotations.GwtCompatible;
import com.google.common.base.Objects;
import java.util.Collection;
import java.util.Iterator;
import java.util.Map;
import java.util.Set;
import javax.annotation.Nullable;
/**
* A map which forwards all its method calls to another map. Subclasses should
* override one or more methods to modify the behavior of the backing map as
* desired per the <a
* href="http://en.wikipedia.org/wiki/Decorator_pattern">decorator pattern</a>.
*
* <p><i>Warning:</i> The methods of {@code ForwardingMap} forward
* <i>indiscriminately</i> to the methods of the delegate. For example,
* overriding {@link #put} alone <i>will not</i> change the behavior of {@link
* #putAll}, which can lead to unexpected behavior. In this case, you should
* override {@code putAll} as well, either providing your own implementation, or
* delegating to the provided {@code standardPutAll} method.
*
* <p>Each of the {@code standard} methods, where appropriate, use {@link
* Objects#equal} to test equality for both keys and values. This may not be
* the desired behavior for map implementations that use non-standard notions of
* key equality, such as a {@code SortedMap} whose comparator is not consistent
* with {@code equals}.
*
* <p>The {@code standard} methods and the collection views they return are not
* guaranteed to be thread-safe, even when all of the methods that they depend
* on are thread-safe.
*
* @author Kevin Bourrillion
* @author Jared Levy
* @author Louis Wasserman
* @since 2.0 (imported from Google Collections Library)
*/
@GwtCompatible
public abstract class ForwardingMap<K, V> extends ForwardingObject
implements Map<K, V> {
// TODO(user): identify places where thread safety is actually lost
/** Constructor for use by subclasses. */
protected ForwardingMap() {}
@Override protected abstract Map<K, V> delegate();
@Override
public int size() {
return delegate().size();
}
@Override
public boolean isEmpty() {
return delegate().isEmpty();
}
@Override
public V remove(Object object) {
return delegate().remove(object);
}
@Override
public void clear() {
delegate().clear();
}
@Override
public boolean containsKey(Object key) {
return delegate().containsKey(key);
}
@Override
public boolean containsValue(Object value) {
return delegate().containsValue(value);
}
@Override
public V get(Object key) {
return delegate().get(key);
}
@Override
public V put(K key, V value) {
return delegate().put(key, value);
}
@Override
public void putAll(Map<? extends K, ? extends V> map) {
delegate().putAll(map);
}
@Override
public Set<K> keySet() {
return delegate().keySet();
}
@Override
public Collection<V> values() {
return delegate().values();
}
@Override
public Set<Entry<K, V>> entrySet() {
return delegate().entrySet();
}
@Override public boolean equals(@Nullable Object object) {
return object == this || delegate().equals(object);
}
@Override public int hashCode() {
return delegate().hashCode();
}
/**
* A sensible definition of {@link #putAll(Map)} in terms of {@link
* #put(Object, Object)}. If you override {@link #put(Object, Object)}, you
* may wish to override {@link #putAll(Map)} to forward to this
* implementation.
*
* @since 7.0
*/
@Beta protected void standardPutAll(Map<? extends K, ? extends V> map) {
Maps.putAllImpl(this, map);
}
/**
* A sensible, albeit inefficient, definition of {@link #remove} in terms of
* the {@code iterator} method of {@link #entrySet}. If you override {@link
* #entrySet}, you may wish to override {@link #remove} to forward to this
* implementation.
*
* <p>Alternately, you may wish to override {@link #remove} with {@code
* keySet().remove}, assuming that approach would not lead to an infinite
* loop.
*
* @since 7.0
*/
@Beta protected V standardRemove(@Nullable Object key) {
Iterator<Entry<K, V>> entryIterator = entrySet().iterator();
while (entryIterator.hasNext()) {
Entry<K, V> entry = entryIterator.next();
if (Objects.equal(entry.getKey(), key)) {
V value = entry.getValue();
entryIterator.remove();
return value;
}
}
return null;
}
/**
* A sensible definition of {@link #clear} in terms of the {@code iterator}
* method of {@link #entrySet}. In many cases, you may wish to override
* {@link #clear} to forward to this implementation.
*
* @since 7.0
*/
@Beta protected void standardClear() {
Iterator<Entry<K, V>> entryIterator = entrySet().iterator();
while (entryIterator.hasNext()) {
entryIterator.next();
entryIterator.remove();
}
}
/**
* A sensible implementation of {@link Map#keySet} in terms of the following
* methods: {@link ForwardingMap#clear}, {@link ForwardingMap#containsKey},
* {@link ForwardingMap#isEmpty}, {@link ForwardingMap#remove}, {@link
* ForwardingMap#size}, and the {@link Set#iterator} method of {@link
* ForwardingMap#entrySet}. In many cases, you may wish to override {@link
* ForwardingMap#keySet} to forward to this implementation or a subclass
* thereof.
*
* @since 10.0
*/
@Beta
protected class StandardKeySet extends Maps.KeySet<K, V> {
/** Constructor for use by subclasses. */
public StandardKeySet() {}
@Override
Map<K, V> map() {
return ForwardingMap.this;
}
}
/**
* A sensible, albeit inefficient, definition of {@link #containsKey} in terms
* of the {@code iterator} method of {@link #entrySet}. If you override {@link
* #entrySet}, you may wish to override {@link #containsKey} to forward to
* this implementation.
*
* @since 7.0
*/
@Beta protected boolean standardContainsKey(@Nullable Object key) {
return Maps.containsKeyImpl(this, key);
}
/**
* A sensible implementation of {@link Map#values} in terms of the following
* methods: {@link ForwardingMap#clear}, {@link ForwardingMap#containsValue},
* {@link ForwardingMap#isEmpty}, {@link ForwardingMap#size}, and the {@link
* Set#iterator} method of {@link ForwardingMap#entrySet}. In many cases, you
* may wish to override {@link ForwardingMap#values} to forward to this
* implementation or a subclass thereof.
*
* @since 10.0
*/
@Beta
protected class StandardValues extends Maps.Values<K, V> {
/** Constructor for use by subclasses. */
public StandardValues() {}
@Override
Map<K, V> map() {
return ForwardingMap.this;
}
}
/**
* A sensible definition of {@link #containsValue} in terms of the {@code
* iterator} method of {@link #entrySet}. If you override {@link #entrySet},
* you may wish to override {@link #containsValue} to forward to this
* implementation.
*
* @since 7.0
*/
@Beta protected boolean standardContainsValue(@Nullable Object value) {
return Maps.containsValueImpl(this, value);
}
/**
* A sensible implementation of {@link Map#entrySet} in terms of the following
* methods: {@link ForwardingMap#clear}, {@link ForwardingMap#containsKey},
* {@link ForwardingMap#get}, {@link ForwardingMap#isEmpty}, {@link
* ForwardingMap#remove}, and {@link ForwardingMap#size}. In many cases, you
* may wish to override {@link #entrySet} to forward to this implementation
* or a subclass thereof.
*
* @since 10.0
*/
@Beta
protected abstract class StandardEntrySet extends Maps.EntrySet<K, V> {
/** Constructor for use by subclasses. */
public StandardEntrySet() {}
@Override
Map<K, V> map() {
return ForwardingMap.this;
}
}
/**
* A sensible definition of {@link #isEmpty} in terms of the {@code iterator}
* method of {@link #entrySet}. If you override {@link #entrySet}, you may
* wish to override {@link #isEmpty} to forward to this implementation.
*
* @since 7.0
*/
@Beta protected boolean standardIsEmpty() {
return !entrySet().iterator().hasNext();
}
/**
* A sensible definition of {@link #equals} in terms of the {@code equals}
* method of {@link #entrySet}. If you override {@link #entrySet}, you may
* wish to override {@link #equals} to forward to this implementation.
*
* @since 7.0
*/
@Beta protected boolean standardEquals(@Nullable Object object) {
return Maps.equalsImpl(this, object);
}
/**
* A sensible definition of {@link #hashCode} in terms of the {@code iterator}
* method of {@link #entrySet}. If you override {@link #entrySet}, you may
* wish to override {@link #hashCode} to forward to this implementation.
*
* @since 7.0
*/
@Beta protected int standardHashCode() {
return Sets.hashCodeImpl(entrySet());
}
/**
* A sensible definition of {@link #toString} in terms of the {@code iterator}
* method of {@link #entrySet}. If you override {@link #entrySet}, you may
* wish to override {@link #toString} to forward to this implementation.
*
* @since 7.0
*/
@Beta protected String standardToString() {
return Maps.toStringImpl(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 com.google.common.base.Preconditions;
import java.util.Comparator;
import javax.annotation.Nullable;
/**
* List returned by {@code ImmutableSortedSet.asList()} when the set isn't empty.
*
* @author Jared Levy
* @author Louis Wasserman
*/
@SuppressWarnings("serial")
final class ImmutableSortedAsList<E> extends ImmutableList<E> implements SortedIterable<E> {
private final transient ImmutableSortedSet<E> backingSet;
private final transient ImmutableList<E> backingList;
ImmutableSortedAsList(
ImmutableSortedSet<E> backingSet, ImmutableList<E> backingList) {
this.backingSet = backingSet;
this.backingList = backingList;
}
@Override public Comparator<? super E> comparator() {
return backingSet.comparator();
}
// Override contains(), indexOf(), and lastIndexOf() to be O(log N) instead of O(N).
@Override public boolean contains(@Nullable Object target) {
// TODO: why not contains(target)?
return backingSet.indexOf(target) >= 0;
}
@Override public int indexOf(@Nullable Object target) {
return backingSet.indexOf(target);
}
@Override public int lastIndexOf(@Nullable Object target) {
return backingSet.indexOf(target);
}
// The returned ImmutableSortedAsList maintains the contains(), indexOf(), and
// lastIndexOf() performance benefits.
@Override public ImmutableList<E> subList(int fromIndex, int toIndex) {
Preconditions.checkPositionIndexes(fromIndex, toIndex, size());
return (fromIndex == toIndex) ? ImmutableList.<E>of()
: new RegularImmutableSortedSet<E>(
backingList.subList(fromIndex, toIndex), backingSet.comparator())
.asList();
}
// The ImmutableAsList serialized form has the correct behavior.
@Override Object writeReplace() {
return new ImmutableAsList.SerializedForm(backingSet);
}
@Override public UnmodifiableIterator<E> iterator() {
return backingList.iterator();
}
@Override public E get(int index) {
return backingList.get(index);
}
@Override public UnmodifiableListIterator<E> listIterator() {
return backingList.listIterator();
}
@Override public UnmodifiableListIterator<E> listIterator(int index) {
return backingList.listIterator(index);
}
@Override public int size() {
return backingList.size();
}
@Override public boolean equals(@Nullable Object obj) {
return backingList.equals(obj);
}
@Override public int hashCode() {
return backingList.hashCode();
}
@Override boolean isPartialView() {
return backingList.isPartialView();
}
}
| 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.annotations.GwtCompatible;
/**
* Implementation of {@link ImmutableListMultimap} with no entries.
*
* @author Mike Ward
*/
@GwtCompatible(serializable = true)
class EmptyImmutableSetMultimap extends ImmutableSetMultimap<Object, Object> {
static final EmptyImmutableSetMultimap INSTANCE
= new EmptyImmutableSetMultimap();
private EmptyImmutableSetMultimap() {
super(ImmutableMap.<Object, ImmutableSet<Object>>of(), 0, null);
}
private Object readResolve() {
return INSTANCE; // preserve singleton property
}
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.collect;
import static com.google.common.collect.Multisets.setCountImpl;
import com.google.common.annotations.GwtCompatible;
import com.google.common.base.Objects;
import java.util.AbstractCollection;
import java.util.Collection;
import java.util.Iterator;
import java.util.Set;
import javax.annotation.Nullable;
/**
* This class provides a skeletal implementation of the {@link Multiset}
* interface. A new multiset implementation can be created easily by extending
* this class and implementing the {@link Multiset#entrySet()} method, plus
* optionally overriding {@link #add(Object, int)} and
* {@link #remove(Object, int)} to enable modifications to the multiset.
*
* <p>The {@link #count} and {@link #size} implementations all iterate across
* the set returned by {@link Multiset#entrySet()}, as do many methods acting on
* the set returned by {@link #elementSet()}. Override those methods for better
* performance.
*
* @author Kevin Bourrillion
* @author Louis Wasserman
*/
@GwtCompatible
abstract class AbstractMultiset<E> extends AbstractCollection<E>
implements Multiset<E> {
// Query Operations
@Override public int size() {
return Multisets.sizeImpl(this);
}
@Override public boolean isEmpty() {
return entrySet().isEmpty();
}
@Override public boolean contains(@Nullable Object element) {
return count(element) > 0;
}
@Override public Iterator<E> iterator() {
return Multisets.iteratorImpl(this);
}
@Override
public int count(Object element) {
for (Entry<E> entry : entrySet()) {
if (Objects.equal(entry.getElement(), element)) {
return entry.getCount();
}
}
return 0;
}
// Modification Operations
@Override public boolean add(@Nullable E element) {
add(element, 1);
return true;
}
@Override
public int add(E element, int occurrences) {
throw new UnsupportedOperationException();
}
@Override public boolean remove(Object element) {
return remove(element, 1) > 0;
}
@Override
public int remove(Object element, int occurrences) {
throw new UnsupportedOperationException();
}
@Override
public int setCount(E element, int count) {
return setCountImpl(this, element, count);
}
@Override
public boolean setCount(E element, int oldCount, int newCount) {
return setCountImpl(this, element, oldCount, newCount);
}
// Bulk Operations
/**
* {@inheritDoc}
*
* <p>This implementation is highly efficient when {@code elementsToAdd}
* is itself a {@link Multiset}.
*/
@Override public boolean addAll(Collection<? extends E> elementsToAdd) {
return Multisets.addAllImpl(this, elementsToAdd);
}
@Override public boolean removeAll(Collection<?> elementsToRemove) {
return Multisets.removeAllImpl(this, elementsToRemove);
}
@Override public boolean retainAll(Collection<?> elementsToRetain) {
return Multisets.retainAllImpl(this, elementsToRetain);
}
@Override public void clear() {
Iterators.clear(entryIterator());
}
// Views
private transient Set<E> elementSet;
@Override
public Set<E> elementSet() {
Set<E> result = elementSet;
if (result == null) {
elementSet = result = createElementSet();
}
return result;
}
/**
* Creates a new instance of this multiset's element set, which will be
* returned by {@link #elementSet()}.
*/
Set<E> createElementSet() {
return new ElementSet();
}
class ElementSet extends Multisets.ElementSet<E> {
@Override
Multiset<E> multiset() {
return AbstractMultiset.this;
}
}
abstract Iterator<Entry<E>> entryIterator();
abstract int distinctElements();
private transient Set<Entry<E>> entrySet;
@Override public Set<Entry<E>> entrySet() {
Set<Entry<E>> result = entrySet;
return (result == null) ? entrySet = createEntrySet() : result;
}
class EntrySet extends Multisets.EntrySet<E> {
@Override Multiset<E> multiset() {
return AbstractMultiset.this;
}
@Override public Iterator<Entry<E>> iterator() {
return entryIterator();
}
@Override public int size() {
return distinctElements();
}
}
Set<Entry<E>> createEntrySet() {
return new EntrySet();
}
// Object methods
/**
* {@inheritDoc}
*
* <p>This implementation returns {@code true} if {@code object} is a multiset
* of the same size and if, for each element, the two multisets have the same
* count.
*/
@Override public boolean equals(@Nullable Object object) {
return Multisets.equalsImpl(this, object);
}
/**
* {@inheritDoc}
*
* <p>This implementation returns the hash code of {@link
* Multiset#entrySet()}.
*/
@Override public int hashCode() {
return entrySet().hashCode();
}
/**
* {@inheritDoc}
*
* <p>This implementation returns the result of invoking {@code toString} on
* {@link Multiset#entrySet()}.
*/
@Override public String toString() {
return entrySet().toString();
}
}
| 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 static com.google.common.base.Preconditions.checkArgument;
import static com.google.common.base.Preconditions.checkNotNull;
import static com.google.common.collect.BoundType.CLOSED;
import com.google.common.annotations.GwtCompatible;
import com.google.common.annotations.GwtIncompatible;
import java.io.Serializable;
import java.util.Collection;
import javax.annotation.Nullable;
/**
* An implementation of {@link ContiguousSet} that contains one or more elements.
*
* @author Gregory Kick
*/
@GwtCompatible(emulated = true)
@SuppressWarnings("unchecked") // allow ungenerified Comparable types
final class RegularContiguousSet<C extends Comparable> extends ContiguousSet<C> {
private final Range<C> range;
RegularContiguousSet(Range<C> range, DiscreteDomain<C> domain) {
super(domain);
this.range = range;
}
// Abstract method doesn't exist in GWT emulation
/* @Override */ ContiguousSet<C> headSetImpl(C toElement, boolean inclusive) {
return range.intersection(Ranges.upTo(toElement, BoundType.forBoolean(inclusive)))
.asSet(domain);
}
// Abstract method doesn't exist in GWT emulation
/* @Override */ int indexOf(Object target) {
return contains(target) ? (int) domain.distance(first(), (C) target) : -1;
}
// Abstract method doesn't exist in GWT emulation
/* @Override */ ContiguousSet<C> subSetImpl(C fromElement, boolean fromInclusive, C toElement,
boolean toInclusive) {
return range.intersection(Ranges.range(fromElement, BoundType.forBoolean(fromInclusive),
toElement, BoundType.forBoolean(toInclusive))).asSet(domain);
}
// Abstract method doesn't exist in GWT emulation
/* @Override */ ContiguousSet<C> tailSetImpl(C fromElement, boolean inclusive) {
return range.intersection(Ranges.downTo(fromElement, BoundType.forBoolean(inclusive)))
.asSet(domain);
}
@Override public UnmodifiableIterator<C> iterator() {
return new AbstractSequentialIterator<C>(first()) {
final C last = last();
@Override
protected C computeNext(C previous) {
return equalsOrThrow(previous, last) ? null : domain.next(previous);
}
};
}
private static boolean equalsOrThrow(Comparable<?> left, @Nullable Comparable<?> right) {
return right != null && Range.compareOrThrow(left, right) == 0;
}
@Override boolean isPartialView() {
return false;
}
@Override public C first() {
return range.lowerBound.leastValueAbove(domain);
}
@Override public C last() {
return range.upperBound.greatestValueBelow(domain);
}
@Override public int size() {
long distance = domain.distance(first(), last());
return (distance >= Integer.MAX_VALUE) ? Integer.MAX_VALUE : (int) distance + 1;
}
@Override public boolean contains(Object object) {
try {
return range.contains((C) object);
} catch (ClassCastException e) {
return false;
}
}
@Override public boolean containsAll(Collection<?> targets) {
try {
return range.containsAll((Iterable<? extends C>) targets);
} catch (ClassCastException e) {
return false;
}
}
@Override public boolean isEmpty() {
return false;
}
// copied to make sure not to use the GWT-emulated version
@Override public Object[] toArray() {
return ObjectArrays.toArrayImpl(this);
}
// copied to make sure not to use the GWT-emulated version
@Override public <T> T[] toArray(T[] other) {
return ObjectArrays.toArrayImpl(this, other);
}
@Override public ContiguousSet<C> intersection(ContiguousSet<C> other) {
checkNotNull(other);
checkArgument(this.domain.equals(other.domain));
if (other.isEmpty()) {
return other;
} else {
C lowerEndpoint = Ordering.natural().max(this.first(), other.first());
C upperEndpoint = Ordering.natural().min(this.last(), other.last());
return (lowerEndpoint.compareTo(upperEndpoint) < 0)
? Ranges.closed(lowerEndpoint, upperEndpoint).asSet(domain)
: new EmptyContiguousSet<C>(domain);
}
}
@Override public Range<C> range() {
return range(CLOSED, CLOSED);
}
@Override public Range<C> range(BoundType lowerBoundType, BoundType upperBoundType) {
return Ranges.create(range.lowerBound.withLowerBoundType(lowerBoundType, domain),
range.upperBound.withUpperBoundType(upperBoundType, domain));
}
@Override public boolean equals(Object object) {
if (object == this) {
return true;
} else if (object instanceof RegularContiguousSet<?>) {
RegularContiguousSet<?> that = (RegularContiguousSet<?>) object;
if (this.domain.equals(that.domain)) {
return this.first().equals(that.first())
&& this.last().equals(that.last());
}
}
return super.equals(object);
}
// copied to make sure not to use the GWT-emulated version
@Override public int hashCode() {
return Sets.hashCodeImpl(this);
}
@GwtIncompatible("serialization")
private static final class SerializedForm<C extends Comparable> implements Serializable {
final Range<C> range;
final DiscreteDomain<C> domain;
private SerializedForm(Range<C> range, DiscreteDomain<C> domain) {
this.range = range;
this.domain = domain;
}
private Object readResolve() {
return new RegularContiguousSet<C>(range, domain);
}
}
@GwtIncompatible("serialization")
@Override Object writeReplace() {
return new SerializedForm<C>(range, domain);
}
private static final long serialVersionUID = 0;
}
| 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 com.google.common.collect;
import static com.google.common.base.Preconditions.checkNotNull;
import com.google.common.annotations.GwtCompatible;
import com.google.common.base.Objects;
import java.util.Map;
import javax.annotation.Nullable;
/**
* An implementation of {@link ImmutableTable} that holds a single cell.
*
* @author gak@google.com (Gregory Kick)
*/
@GwtCompatible
final class SingletonImmutableTable<R, C, V> extends ImmutableTable<R, C, V> {
private final R singleRowKey;
private final C singleColumnKey;
private final V singleValue;
SingletonImmutableTable(R rowKey, C columnKey, V value) {
this.singleRowKey = checkNotNull(rowKey);
this.singleColumnKey = checkNotNull(columnKey);
this.singleValue = checkNotNull(value);
}
SingletonImmutableTable(Cell<R, C, V> cell) {
this(cell.getRowKey(), cell.getColumnKey(), cell.getValue());
}
@Override public ImmutableSet<Cell<R, C, V>> cellSet() {
return ImmutableSet.of(
Tables.immutableCell(singleRowKey, singleColumnKey, singleValue));
}
@Override public ImmutableMap<R, V> column(C columnKey) {
checkNotNull(columnKey);
return containsColumn(columnKey)
? ImmutableMap.of(singleRowKey, singleValue)
: ImmutableMap.<R, V>of();
}
@Override public ImmutableSet<C> columnKeySet() {
return ImmutableSet.of(singleColumnKey);
}
@Override public ImmutableMap<C, Map<R, V>> columnMap() {
return ImmutableMap.of(singleColumnKey,
(Map<R, V>) ImmutableMap.of(singleRowKey, singleValue));
}
@Override public boolean contains(@Nullable Object rowKey,
@Nullable Object columnKey) {
return containsRow(rowKey) && containsColumn(columnKey);
}
@Override public boolean containsColumn(@Nullable Object columnKey) {
return Objects.equal(this.singleColumnKey, columnKey);
}
@Override public boolean containsRow(@Nullable Object rowKey) {
return Objects.equal(this.singleRowKey, rowKey);
}
@Override public boolean containsValue(@Nullable Object value) {
return Objects.equal(this.singleValue, value);
}
@Override public V get(@Nullable Object rowKey, @Nullable Object columnKey) {
return contains(rowKey, columnKey) ? singleValue : null;
}
@Override public boolean isEmpty() {
return false;
}
@Override public ImmutableMap<C, V> row(R rowKey) {
checkNotNull(rowKey);
return containsRow(rowKey)
? ImmutableMap.of(singleColumnKey, singleValue)
: ImmutableMap.<C, V>of();
}
@Override public ImmutableSet<R> rowKeySet() {
return ImmutableSet.of(singleRowKey);
}
@Override public ImmutableMap<R, Map<C, V>> rowMap() {
return ImmutableMap.of(singleRowKey,
(Map<C, V>) ImmutableMap.of(singleColumnKey, singleValue));
}
@Override public int size() {
return 1;
}
@Override public ImmutableCollection<V> values() {
return ImmutableSet.of(singleValue);
}
@Override public boolean equals(@Nullable Object obj) {
if (obj == this) {
return true;
} else if (obj instanceof Table<?, ?, ?>) {
Table<?, ?, ?> that = (Table<?, ?, ?>) obj;
if (that.size() == 1) {
Cell<?, ?, ?> thatCell = that.cellSet().iterator().next();
return Objects.equal(this.singleRowKey, thatCell.getRowKey()) &&
Objects.equal(this.singleColumnKey, thatCell.getColumnKey()) &&
Objects.equal(this.singleValue, thatCell.getValue());
}
}
return false;
}
@Override public int hashCode() {
return Objects.hashCode(singleRowKey, singleColumnKey, singleValue);
}
@Override public String toString() {
return new StringBuilder()
.append('{')
.append(singleRowKey)
.append("={")
.append(singleColumnKey)
.append('=')
.append(singleValue)
.append("}}")
.toString();
}
}
| 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.GwtCompatible;
import java.util.Map;
import javax.annotation.Nullable;
/**
* Implementation of {@link ImmutableMap} with exactly one entry.
*
* @author Jesse Wilson
* @author Kevin Bourrillion
*/
@GwtCompatible(serializable = true, emulated = true)
@SuppressWarnings("serial") // uses writeReplace(), not default serialization
final class SingletonImmutableMap<K, V> extends ImmutableMap<K, V> {
final transient K singleKey;
final transient V singleValue;
private transient Entry<K, V> entry;
SingletonImmutableMap(K singleKey, V singleValue) {
this.singleKey = singleKey;
this.singleValue = singleValue;
}
SingletonImmutableMap(Entry<K, V> entry) {
this.entry = entry;
this.singleKey = entry.getKey();
this.singleValue = entry.getValue();
}
private Entry<K, V> entry() {
Entry<K, V> e = entry;
return (e == null)
? (entry = Maps.immutableEntry(singleKey, singleValue)) : e;
}
@Override public V get(@Nullable Object key) {
return singleKey.equals(key) ? singleValue : null;
}
@Override
public int size() {
return 1;
}
@Override public boolean isEmpty() {
return false;
}
@Override public boolean containsKey(@Nullable Object key) {
return singleKey.equals(key);
}
@Override public boolean containsValue(@Nullable Object value) {
return singleValue.equals(value);
}
@Override boolean isPartialView() {
return false;
}
private transient ImmutableSet<Entry<K, V>> entrySet;
@Override public ImmutableSet<Entry<K, V>> entrySet() {
ImmutableSet<Entry<K, V>> es = entrySet;
return (es == null) ? (entrySet = ImmutableSet.of(entry())) : es;
}
private transient ImmutableSet<K> keySet;
@Override public ImmutableSet<K> keySet() {
ImmutableSet<K> ks = keySet;
return (ks == null) ? (keySet = ImmutableSet.of(singleKey)) : ks;
}
private transient ImmutableCollection<V> values;
@Override public ImmutableCollection<V> values() {
ImmutableCollection<V> v = values;
return (v == null) ? (values = new Values<V>(singleValue)) : v;
}
@SuppressWarnings("serial") // uses writeReplace(), not default serialization
private static class Values<V> extends ImmutableCollection<V> {
final V singleValue;
Values(V singleValue) {
this.singleValue = singleValue;
}
@Override public boolean contains(Object object) {
return singleValue.equals(object);
}
@Override public boolean isEmpty() {
return false;
}
@Override
public int size() {
return 1;
}
@Override public UnmodifiableIterator<V> iterator() {
return Iterators.singletonIterator(singleValue);
}
@Override boolean isPartialView() {
return true;
}
}
@Override public boolean equals(@Nullable Object object) {
if (object == this) {
return true;
}
if (object instanceof Map) {
Map<?, ?> that = (Map<?, ?>) object;
if (that.size() != 1) {
return false;
}
Entry<?, ?> entry = that.entrySet().iterator().next();
return singleKey.equals(entry.getKey())
&& singleValue.equals(entry.getValue());
}
return false;
}
@Override public int hashCode() {
return singleKey.hashCode() ^ singleValue.hashCode();
}
@Override public String toString() {
return new StringBuilder()
.append('{')
.append(singleKey.toString())
.append('=')
.append(singleValue.toString())
.append('}')
.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.collect;
import static com.google.common.base.Preconditions.checkNotNull;
import static com.google.common.base.Preconditions.checkState;
import com.google.common.base.Equivalence;
import com.google.common.base.Function;
import com.google.common.base.Throwables;
import com.google.common.collect.MapMaker.RemovalCause;
import com.google.common.collect.MapMaker.RemovalListener;
import java.io.IOException;
import java.io.ObjectInputStream;
import java.io.ObjectOutputStream;
import java.io.Serializable;
import java.lang.ref.ReferenceQueue;
import java.util.concurrent.ConcurrentMap;
import java.util.concurrent.ExecutionException;
import java.util.concurrent.atomic.AtomicReferenceArray;
import javax.annotation.Nullable;
import javax.annotation.concurrent.GuardedBy;
/**
* Adds computing functionality to {@link MapMakerInternalMap}.
*
* @author Bob Lee
* @author Charles Fry
*/
class ComputingConcurrentHashMap<K, V> extends MapMakerInternalMap<K, V> {
final Function<? super K, ? extends V> computingFunction;
/**
* Creates a new, empty map with the specified strategy, initial capacity, load factor and
* concurrency level.
*/
ComputingConcurrentHashMap(MapMaker builder,
Function<? super K, ? extends V> computingFunction) {
super(builder);
this.computingFunction = checkNotNull(computingFunction);
}
@Override
Segment<K, V> createSegment(int initialCapacity, int maxSegmentSize) {
return new ComputingSegment<K, V>(this, initialCapacity, maxSegmentSize);
}
@Override
ComputingSegment<K, V> segmentFor(int hash) {
return (ComputingSegment<K, V>) super.segmentFor(hash);
}
V getOrCompute(K key) throws ExecutionException {
int hash = hash(checkNotNull(key));
return segmentFor(hash).getOrCompute(key, hash, computingFunction);
}
@SuppressWarnings("serial") // This class is never serialized.
static final class ComputingSegment<K, V> extends Segment<K, V> {
ComputingSegment(MapMakerInternalMap<K, V> map, int initialCapacity, int maxSegmentSize) {
super(map, initialCapacity, maxSegmentSize);
}
V getOrCompute(K key, int hash, Function<? super K, ? extends V> computingFunction)
throws ExecutionException {
try {
outer: while (true) {
// don't call getLiveEntry, which would ignore computing values
ReferenceEntry<K, V> e = getEntry(key, hash);
if (e != null) {
V value = getLiveValue(e);
if (value != null) {
recordRead(e);
return value;
}
}
// at this point e is either null, computing, or expired;
// avoid locking if it's already computing
if (e == null || !e.getValueReference().isComputingReference()) {
boolean createNewEntry = true;
ComputingValueReference<K, V> computingValueReference = null;
lock();
try {
preWriteCleanup();
int newCount = this.count - 1;
AtomicReferenceArray<ReferenceEntry<K, V>> table = this.table;
int index = hash & (table.length() - 1);
ReferenceEntry<K, V> first = table.get(index);
for (e = first; e != null; e = e.getNext()) {
K entryKey = e.getKey();
if (e.getHash() == hash && entryKey != null
&& map.keyEquivalence.equivalent(key, entryKey)) {
ValueReference<K, V> valueReference = e.getValueReference();
if (valueReference.isComputingReference()) {
createNewEntry = false;
} else {
V value = e.getValueReference().get();
if (value == null) {
enqueueNotification(entryKey, hash, value, RemovalCause.COLLECTED);
} else if (map.expires() && map.isExpired(e)) {
// This is a duplicate check, as preWriteCleanup already purged expired
// entries, but let's accomodate an incorrect expiration queue.
enqueueNotification(entryKey, hash, value, RemovalCause.EXPIRED);
} else {
recordLockedRead(e);
return value;
}
// immediately reuse invalid entries
evictionQueue.remove(e);
expirationQueue.remove(e);
this.count = newCount; // write-volatile
}
break;
}
}
if (createNewEntry) {
computingValueReference = new ComputingValueReference<K, V>(computingFunction);
if (e == null) {
e = newEntry(key, hash, first);
e.setValueReference(computingValueReference);
table.set(index, e);
} else {
e.setValueReference(computingValueReference);
}
}
} finally {
unlock();
postWriteCleanup();
}
if (createNewEntry) {
// This thread solely created the entry.
return compute(key, hash, e, computingValueReference);
}
}
// The entry already exists. Wait for the computation.
checkState(!Thread.holdsLock(e), "Recursive computation");
// don't consider expiration as we're concurrent with computation
V value = e.getValueReference().waitForValue();
if (value != null) {
recordRead(e);
return value;
}
// else computing thread will clearValue
continue outer;
}
} finally {
postReadCleanup();
}
}
V compute(K key, int hash, ReferenceEntry<K, V> e,
ComputingValueReference<K, V> computingValueReference)
throws ExecutionException {
V value = null;
long start = System.nanoTime();
long end = 0;
try {
// Synchronizes on the entry to allow failing fast when a recursive computation is
// detected. This is not fool-proof since the entry may be copied when the segment
// is written to.
synchronized (e) {
value = computingValueReference.compute(key, hash);
end = System.nanoTime();
}
if (value != null) {
// putIfAbsent
V oldValue = put(key, hash, value, true);
if (oldValue != null) {
// the computed value was already clobbered
enqueueNotification(key, hash, value, RemovalCause.REPLACED);
}
}
return value;
} finally {
if (end == 0) {
end = System.nanoTime();
}
if (value == null) {
clearValue(key, hash, computingValueReference);
}
}
}
}
/**
* Used to provide computation exceptions to other threads.
*/
private static final class ComputationExceptionReference<K, V> implements ValueReference<K, V> {
final Throwable t;
ComputationExceptionReference(Throwable t) {
this.t = t;
}
@Override
public V get() {
return null;
}
@Override
public ReferenceEntry<K, V> getEntry() {
return null;
}
@Override
public ValueReference<K, V> copyFor(ReferenceQueue<V> queue, ReferenceEntry<K, V> entry) {
return this;
}
@Override
public boolean isComputingReference() {
return false;
}
@Override
public V waitForValue() throws ExecutionException {
throw new ExecutionException(t);
}
@Override
public void clear(ValueReference<K, V> newValue) {}
}
/**
* Used to provide computation result to other threads.
*/
private static final class ComputedReference<K, V> implements ValueReference<K, V> {
final V value;
ComputedReference(@Nullable V value) {
this.value = value;
}
@Override
public V get() {
return value;
}
@Override
public ReferenceEntry<K, V> getEntry() {
return null;
}
@Override
public ValueReference<K, V> copyFor(ReferenceQueue<V> queue, ReferenceEntry<K, V> entry) {
return this;
}
@Override
public boolean isComputingReference() {
return false;
}
@Override
public V waitForValue() {
return get();
}
@Override
public void clear(ValueReference<K, V> newValue) {}
}
private static final class ComputingValueReference<K, V> implements ValueReference<K, V> {
final Function<? super K, ? extends V> computingFunction;
@GuardedBy("ComputingValueReference.this") // writes
volatile ValueReference<K, V> computedReference = unset();
public ComputingValueReference(Function<? super K, ? extends V> computingFunction) {
this.computingFunction = computingFunction;
}
@Override
public V get() {
// All computation lookups go through waitForValue. This method thus is
// only used by put, to whom we always want to appear absent.
return null;
}
@Override
public ReferenceEntry<K, V> getEntry() {
return null;
}
@Override
public ValueReference<K, V> copyFor(ReferenceQueue<V> queue, ReferenceEntry<K, V> entry) {
return this;
}
@Override
public boolean isComputingReference() {
return true;
}
/**
* Waits for a computation to complete. Returns the result of the computation.
*/
@Override
public V waitForValue() throws ExecutionException {
if (computedReference == UNSET) {
boolean interrupted = false;
try {
synchronized (this) {
while (computedReference == UNSET) {
try {
wait();
} catch (InterruptedException ie) {
interrupted = true;
}
}
}
} finally {
if (interrupted) {
Thread.currentThread().interrupt();
}
}
}
return computedReference.waitForValue();
}
@Override
public void clear(ValueReference<K, V> newValue) {
// The pending computation was clobbered by a manual write. Unblock all
// pending gets, and have them return the new value.
setValueReference(newValue);
// TODO(fry): could also cancel computation if we had a thread handle
}
V compute(K key, int hash) throws ExecutionException {
V value;
try {
value = computingFunction.apply(key);
} catch (Throwable t) {
setValueReference(new ComputationExceptionReference<K, V>(t));
throw new ExecutionException(t);
}
setValueReference(new ComputedReference<K, V>(value));
return value;
}
void setValueReference(ValueReference<K, V> valueReference) {
synchronized (this) {
if (computedReference == UNSET) {
computedReference = valueReference;
notifyAll();
}
}
}
}
/**
* Overrides get() to compute on demand. Also throws an exception when {@code null} is returned
* from a computation.
*/
static final class ComputingMapAdapter<K, V>
extends ComputingConcurrentHashMap<K, V> implements Serializable {
private static final long serialVersionUID = 0;
ComputingMapAdapter(MapMaker mapMaker,
Function<? super K, ? extends V> computingFunction) {
super(mapMaker, computingFunction);
}
@SuppressWarnings("unchecked") // unsafe, which is one advantage of Cache over Map
@Override
public V get(Object key) {
V value;
try {
value = getOrCompute((K) key);
} catch (ExecutionException e) {
Throwable cause = e.getCause();
Throwables.propagateIfInstanceOf(cause, ComputationException.class);
throw new ComputationException(cause);
}
if (value == null) {
throw new NullPointerException(computingFunction + " returned null for key " + key + ".");
}
return value;
}
}
// Serialization Support
private static final long serialVersionUID = 4;
@Override
Object writeReplace() {
return new ComputingSerializationProxy<K, V>(keyStrength, valueStrength, keyEquivalence,
valueEquivalence, expireAfterWriteNanos, expireAfterAccessNanos, maximumSize,
concurrencyLevel, removalListener, this, computingFunction);
}
static final class ComputingSerializationProxy<K, V> extends AbstractSerializationProxy<K, V> {
final Function<? super K, ? extends V> computingFunction;
ComputingSerializationProxy(Strength keyStrength, Strength valueStrength,
Equivalence<Object> keyEquivalence, Equivalence<Object> valueEquivalence,
long expireAfterWriteNanos, long expireAfterAccessNanos, int maximumSize,
int concurrencyLevel, RemovalListener<? super K, ? super V> removalListener,
ConcurrentMap<K, V> delegate, Function<? super K, ? extends V> computingFunction) {
super(keyStrength, valueStrength, keyEquivalence, valueEquivalence, expireAfterWriteNanos,
expireAfterAccessNanos, maximumSize, concurrencyLevel, removalListener, delegate);
this.computingFunction = computingFunction;
}
private void writeObject(ObjectOutputStream out) throws IOException {
out.defaultWriteObject();
writeMapTo(out);
}
@SuppressWarnings("deprecation") // self-use
private void readObject(ObjectInputStream in) throws IOException, ClassNotFoundException {
in.defaultReadObject();
MapMaker mapMaker = readMapMaker(in);
delegate = mapMaker.makeComputingMap(computingFunction);
readEntries(in);
}
Object readResolve() {
return delegate;
}
private static final long serialVersionUID = 4;
}
}
| 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 java.util.Map;
import java.util.Set;
import javax.annotation.Nullable;
/**
* Basic implementation of the {@link SetMultimap} interface. It's a wrapper
* around {@link AbstractMultimap} that converts the returned collections into
* {@code Sets}. The {@link #createCollection} method must return a {@code Set}.
*
* @author Jared Levy
*/
@GwtCompatible
abstract class AbstractSetMultimap<K, V>
extends AbstractMultimap<K, V> implements SetMultimap<K, V> {
/**
* Creates a new multimap that uses the provided map.
*
* @param map place to store the mapping from each key to its corresponding
* values
*/
protected AbstractSetMultimap(Map<K, Collection<V>> map) {
super(map);
}
@Override abstract Set<V> createCollection();
// Following Javadoc copied from SetMultimap.
/**
* {@inheritDoc}
*
* <p>Because a {@code SetMultimap} has unique values for a given key, this
* method returns a {@link Set}, instead of the {@link Collection} specified
* in the {@link Multimap} interface.
*/
@Override public Set<V> get(@Nullable K key) {
return (Set<V>) super.get(key);
}
/**
* {@inheritDoc}
*
* <p>Because a {@code SetMultimap} has unique values for a given key, this
* method returns a {@link Set}, instead of the {@link Collection} specified
* in the {@link Multimap} interface.
*/
@Override public Set<Map.Entry<K, V>> entries() {
return (Set<Map.Entry<K, V>>) super.entries();
}
/**
* {@inheritDoc}
*
* <p>Because a {@code SetMultimap} has unique values for a given key, this
* method returns a {@link Set}, instead of the {@link Collection} specified
* in the {@link Multimap} interface.
*/
@Override public Set<V> removeAll(@Nullable Object key) {
return (Set<V>) super.removeAll(key);
}
/**
* {@inheritDoc}
*
* <p>Because a {@code SetMultimap} has unique values for a given key, this
* method returns a {@link Set}, instead of the {@link Collection} specified
* in the {@link Multimap} interface.
*
* <p>Any duplicates in {@code values} will be stored in the multimap once.
*/
@Override public Set<V> replaceValues(
@Nullable K key, Iterable<? extends V> values) {
return (Set<V>) super.replaceValues(key, values);
}
/**
* {@inheritDoc}
*
* <p>Though the method signature doesn't say so explicitly, the returned map
* has {@link Set} values.
*/
@Override public Map<K, Collection<V>> asMap() {
return super.asMap();
}
/**
* 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} if the method increased the size of the multimap, or
* {@code false} if the multimap already contained the key-value pair
*/
@Override public boolean put(K key, V value) {
return super.put(key, value);
}
/**
* Compares the specified object to this multimap for equality.
*
* <p>Two {@code SetMultimap} instances are equal if, for each key, they
* contain the same values. Equality does not depend on the ordering of keys
* or values.
*/
@Override public boolean equals(@Nullable Object object) {
return super.equals(object);
}
private static final long serialVersionUID = 7431625294878419160L;
}
| 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.checkState;
import com.google.common.annotations.GwtCompatible;
import com.google.common.annotations.GwtIncompatible;
import com.google.common.base.Objects;
import java.io.IOException;
import java.io.ObjectInputStream;
import java.io.ObjectOutputStream;
import java.io.Serializable;
import java.util.Collection;
import java.util.Iterator;
import java.util.Map;
import java.util.Set;
import javax.annotation.Nullable;
/**
* A general-purpose bimap implementation using any two backing {@code Map}
* instances.
*
* <p>Note that this class contains {@code equals()} calls that keep it from
* supporting {@code IdentityHashMap} backing maps.
*
* @author Kevin Bourrillion
* @author Mike Bostock
*/
@GwtCompatible(emulated = true)
abstract class AbstractBiMap<K, V> extends ForwardingMap<K, V>
implements BiMap<K, V>, Serializable {
private transient Map<K, V> delegate;
transient AbstractBiMap<V, K> inverse;
/** Package-private constructor for creating a map-backed bimap. */
AbstractBiMap(Map<K, V> forward, Map<V, K> backward) {
setDelegates(forward, backward);
}
/** Private constructor for inverse bimap. */
private AbstractBiMap(Map<K, V> backward, AbstractBiMap<V, K> forward) {
delegate = backward;
inverse = forward;
}
@Override protected Map<K, V> delegate() {
return delegate;
}
/**
* Returns its input, or throws an exception if this is not a valid key.
*/
K checkKey(K key) {
return key;
}
/**
* Returns its input, or throws an exception if this is not a valid value.
*/
V checkValue(V value) {
return value;
}
/**
* Specifies the delegate maps going in each direction. Called by the
* constructor and by subclasses during deserialization.
*/
void setDelegates(Map<K, V> forward, Map<V, K> backward) {
checkState(delegate == null);
checkState(inverse == null);
checkArgument(forward.isEmpty());
checkArgument(backward.isEmpty());
checkArgument(forward != backward);
delegate = forward;
inverse = new Inverse<V, K>(backward, this);
}
void setInverse(AbstractBiMap<V, K> inverse) {
this.inverse = inverse;
}
// Query Operations (optimizations)
@Override public boolean containsValue(Object value) {
return inverse.containsKey(value);
}
// Modification Operations
@Override public V put(K key, V value) {
return putInBothMaps(key, value, false);
}
@Override
public V forcePut(K key, V value) {
return putInBothMaps(key, value, true);
}
private V putInBothMaps(@Nullable K key, @Nullable V value, boolean force) {
checkKey(key);
checkValue(value);
boolean containedKey = containsKey(key);
if (containedKey && Objects.equal(value, get(key))) {
return value;
}
if (force) {
inverse().remove(value);
} else {
checkArgument(!containsValue(value), "value already present: %s", value);
}
V oldValue = delegate.put(key, value);
updateInverseMap(key, containedKey, oldValue, value);
return oldValue;
}
private void updateInverseMap(
K key, boolean containedKey, V oldValue, V newValue) {
if (containedKey) {
removeFromInverseMap(oldValue);
}
inverse.delegate.put(newValue, key);
}
@Override public V remove(Object key) {
return containsKey(key) ? removeFromBothMaps(key) : null;
}
private V removeFromBothMaps(Object key) {
V oldValue = delegate.remove(key);
removeFromInverseMap(oldValue);
return oldValue;
}
private void removeFromInverseMap(V oldValue) {
inverse.delegate.remove(oldValue);
}
// Bulk Operations
@Override public void putAll(Map<? extends K, ? extends V> map) {
for (Entry<? extends K, ? extends V> entry : map.entrySet()) {
put(entry.getKey(), entry.getValue());
}
}
@Override public void clear() {
delegate.clear();
inverse.delegate.clear();
}
// Views
@Override
public BiMap<V, K> inverse() {
return inverse;
}
private transient Set<K> keySet;
@Override public Set<K> keySet() {
Set<K> result = keySet;
return (result == null) ? keySet = new KeySet() : result;
}
private class KeySet extends ForwardingSet<K> {
@Override protected Set<K> delegate() {
return delegate.keySet();
}
@Override public void clear() {
AbstractBiMap.this.clear();
}
@Override public boolean remove(Object key) {
if (!contains(key)) {
return false;
}
removeFromBothMaps(key);
return true;
}
@Override public boolean removeAll(Collection<?> keysToRemove) {
return standardRemoveAll(keysToRemove);
}
@Override public boolean retainAll(Collection<?> keysToRetain) {
return standardRetainAll(keysToRetain);
}
@Override public Iterator<K> iterator() {
final Iterator<Entry<K, V>> iterator = delegate.entrySet().iterator();
return new Iterator<K>() {
Entry<K, V> entry;
@Override
public boolean hasNext() {
return iterator.hasNext();
}
@Override
public K next() {
entry = iterator.next();
return entry.getKey();
}
@Override
public void remove() {
checkState(entry != null);
V value = entry.getValue();
iterator.remove();
removeFromInverseMap(value);
}
};
}
}
private transient Set<V> valueSet;
@Override public Set<V> values() {
/*
* We can almost reuse the inverse's keySet, except we have to fix the
* iteration order so that it is consistent with the forward map.
*/
Set<V> result = valueSet;
return (result == null) ? valueSet = new ValueSet() : result;
}
private class ValueSet extends ForwardingSet<V> {
final Set<V> valuesDelegate = inverse.keySet();
@Override protected Set<V> delegate() {
return valuesDelegate;
}
@Override public Iterator<V> iterator() {
final Iterator<V> iterator = delegate.values().iterator();
return new Iterator<V>() {
V valueToRemove;
@Override public boolean hasNext() {
return iterator.hasNext();
}
@Override public V next() {
return valueToRemove = iterator.next();
}
@Override public void remove() {
iterator.remove();
removeFromInverseMap(valueToRemove);
}
};
}
@Override public Object[] toArray() {
return standardToArray();
}
@Override public <T> T[] toArray(T[] array) {
return standardToArray(array);
}
@Override public String toString() {
return standardToString();
}
}
private transient 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>> {
final Set<Entry<K, V>> esDelegate = delegate.entrySet();
@Override protected Set<Entry<K, V>> delegate() {
return esDelegate;
}
@Override public void clear() {
AbstractBiMap.this.clear();
}
@Override public boolean remove(Object object) {
if (!esDelegate.contains(object)) {
return false;
}
// safe because esDelgate.contains(object).
Entry<?, ?> entry = (Entry<?, ?>) object;
inverse.delegate.remove(entry.getValue());
/*
* Remove the mapping in inverse before removing from esDelegate because
* if entry is part of esDelegate, entry might be invalidated after the
* mapping is removed from esDelegate.
*/
esDelegate.remove(entry);
return true;
}
@Override public Iterator<Entry<K, V>> iterator() {
final Iterator<Entry<K, V>> iterator = esDelegate.iterator();
return new Iterator<Entry<K, V>>() {
Entry<K, V> entry;
@Override public boolean hasNext() {
return iterator.hasNext();
}
@Override public Entry<K, V> next() {
entry = iterator.next();
final Entry<K, V> finalEntry = entry;
return new ForwardingMapEntry<K, V>() {
@Override protected Entry<K, V> delegate() {
return finalEntry;
}
@Override public V setValue(V value) {
// Preconditions keep the map and inverse consistent.
checkState(contains(this), "entry no longer in map");
// similar to putInBothMaps, but set via entry
if (Objects.equal(value, getValue())) {
return value;
}
checkArgument(!containsValue(value),
"value already present: %s", value);
V oldValue = finalEntry.setValue(value);
checkState(Objects.equal(value, get(getKey())),
"entry no longer in map");
updateInverseMap(getKey(), true, oldValue, value);
return oldValue;
}
};
}
@Override public void remove() {
checkState(entry != null);
V value = entry.getValue();
iterator.remove();
removeFromInverseMap(value);
}
};
}
// See java.util.Collections.CheckedEntrySet for details on attacks.
@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 removeAll(Collection<?> c) {
return standardRemoveAll(c);
}
@Override public boolean retainAll(Collection<?> c) {
return standardRetainAll(c);
}
}
/** The inverse of any other {@code AbstractBiMap} subclass. */
private static class Inverse<K, V> extends AbstractBiMap<K, V> {
private Inverse(Map<K, V> backward, AbstractBiMap<V, K> forward) {
super(backward, forward);
}
/*
* Serialization stores the forward bimap, the inverse of this inverse.
* Deserialization calls inverse() on the forward bimap and returns that
* inverse.
*
* If a bimap and its inverse are serialized together, the deserialized
* instances have inverse() methods that return the other.
*/
@Override
K checkKey(K key) {
return inverse.checkValue(key);
}
@Override
V checkValue(V value) {
return inverse.checkKey(value);
}
/**
* @serialData the forward bimap
*/
@GwtIncompatible("java.io.ObjectOuputStream")
private void writeObject(ObjectOutputStream stream) throws IOException {
stream.defaultWriteObject();
stream.writeObject(inverse());
}
@GwtIncompatible("java.io.ObjectInputStream")
@SuppressWarnings("unchecked") // reading data stored by writeObject
private void readObject(ObjectInputStream stream)
throws IOException, ClassNotFoundException {
stream.defaultReadObject();
setInverse((AbstractBiMap<V, K>) stream.readObject());
}
@GwtIncompatible("Not needed in the emulated source.")
Object readResolve() {
return inverse().inverse();
}
@GwtIncompatible("Not needed in emulated source.")
private static final long serialVersionUID = 0;
}
@GwtIncompatible("Not needed in emulated source.")
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.collect;
import static com.google.common.base.Preconditions.checkNotNull;
import static com.google.common.collect.SortedLists.KeyAbsentBehavior.INVERTED_INSERTION_INDEX;
import static com.google.common.collect.SortedLists.KeyAbsentBehavior.NEXT_HIGHER;
import static com.google.common.collect.SortedLists.KeyAbsentBehavior.NEXT_LOWER;
import static com.google.common.collect.SortedLists.KeyPresentBehavior.ANY_PRESENT;
import com.google.common.primitives.Ints;
import java.util.Comparator;
import java.util.List;
import javax.annotation.Nullable;
/**
* An immutable sorted multiset with one or more distinct elements.
*
* @author Louis Wasserman
*/
final class RegularImmutableSortedMultiset<E> extends ImmutableSortedMultiset<E> {
private static final class CumulativeCountEntry<E> extends Multisets.AbstractEntry<E> {
final E element;
final int count;
final long cumulativeCount;
CumulativeCountEntry(E element, int count, @Nullable CumulativeCountEntry<E> previous) {
this.element = element;
this.count = count;
this.cumulativeCount = count + ((previous == null) ? 0 : previous.cumulativeCount);
}
@Override
public E getElement() {
return element;
}
@Override
public int getCount() {
return count;
}
}
static <E> RegularImmutableSortedMultiset<E> createFromSorted(Comparator<? super E> comparator,
List<? extends Multiset.Entry<E>> entries) {
List<CumulativeCountEntry<E>> newEntries = Lists.newArrayListWithCapacity(entries.size());
CumulativeCountEntry<E> previous = null;
for (Multiset.Entry<E> entry : entries) {
newEntries.add(
previous = new CumulativeCountEntry<E>(entry.getElement(), entry.getCount(), previous));
}
return new RegularImmutableSortedMultiset<E>(comparator, ImmutableList.copyOf(newEntries));
}
final transient ImmutableList<CumulativeCountEntry<E>> entries;
RegularImmutableSortedMultiset(
Comparator<? super E> comparator, ImmutableList<CumulativeCountEntry<E>> entries) {
super(comparator);
this.entries = entries;
assert !entries.isEmpty();
}
ImmutableList<E> elementList() {
return new TransformedImmutableList<CumulativeCountEntry<E>, E>(entries) {
@Override
E transform(CumulativeCountEntry<E> entry) {
return entry.getElement();
}
};
}
@Override
ImmutableSortedSet<E> createElementSet() {
return new RegularImmutableSortedSet<E>(elementList(), comparator());
}
@Override
ImmutableSortedSet<E> createDescendingElementSet() {
return new RegularImmutableSortedSet<E>(elementList().reverse(), reverseComparator());
}
@SuppressWarnings("unchecked")
@Override
UnmodifiableIterator<Multiset.Entry<E>> entryIterator() {
return (UnmodifiableIterator) entries.iterator();
}
@SuppressWarnings("unchecked")
@Override
UnmodifiableIterator<Multiset.Entry<E>> descendingEntryIterator() {
return (UnmodifiableIterator) entries.reverse().iterator();
}
@Override
public CumulativeCountEntry<E> firstEntry() {
return entries.get(0);
}
@Override
public CumulativeCountEntry<E> lastEntry() {
return entries.get(entries.size() - 1);
}
@Override
public int size() {
CumulativeCountEntry<E> firstEntry = firstEntry();
CumulativeCountEntry<E> lastEntry = lastEntry();
return Ints.saturatedCast(
lastEntry.cumulativeCount - firstEntry.cumulativeCount + firstEntry.count);
}
@Override
int distinctElements() {
return entries.size();
}
@Override
boolean isPartialView() {
return entries.isPartialView();
}
@SuppressWarnings("unchecked")
@Override
public int count(@Nullable Object element) {
if (element == null) {
return 0;
}
try {
int index = SortedLists.binarySearch(
elementList(), (E) element, comparator(), ANY_PRESENT, INVERTED_INSERTION_INDEX);
return (index >= 0) ? entries.get(index).getCount() : 0;
} catch (ClassCastException e) {
return 0;
}
}
@Override
public ImmutableSortedMultiset<E> headMultiset(E upperBound, BoundType boundType) {
int index;
switch (boundType) {
case OPEN:
index = SortedLists.binarySearch(
elementList(), checkNotNull(upperBound), comparator(), ANY_PRESENT, NEXT_HIGHER);
break;
case CLOSED:
index = SortedLists.binarySearch(
elementList(), checkNotNull(upperBound), comparator(), ANY_PRESENT, NEXT_LOWER) + 1;
break;
default:
throw new AssertionError();
}
return createSubMultiset(0, index);
}
@Override
public ImmutableSortedMultiset<E> tailMultiset(E lowerBound, BoundType boundType) {
int index;
switch (boundType) {
case OPEN:
index = SortedLists.binarySearch(
elementList(), checkNotNull(lowerBound), comparator(), ANY_PRESENT, NEXT_LOWER) + 1;
break;
case CLOSED:
index = SortedLists.binarySearch(
elementList(), checkNotNull(lowerBound), comparator(), ANY_PRESENT, NEXT_HIGHER);
break;
default:
throw new AssertionError();
}
return createSubMultiset(index, distinctElements());
}
private ImmutableSortedMultiset<E> createSubMultiset(int newFromIndex, int newToIndex) {
if (newFromIndex == 0 && newToIndex == entries.size()) {
return this;
} else if (newFromIndex >= newToIndex) {
return emptyMultiset(comparator());
} else {
return new RegularImmutableSortedMultiset<E>(
comparator(), entries.subList(newFromIndex, newToIndex));
}
}
}
| 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 java.io.Serializable;
import java.math.BigInteger;
/**
* Factories for common {@link DiscreteDomain} instances.
*
* <p>See the Guava User Guide section on <a href=
* "http://code.google.com/p/guava-libraries/wiki/RangesExplained#Discrete_Domains">
* {@code DiscreteDomain}</a>.
*
* @author Gregory Kick
* @since 10.0
*/
@GwtCompatible
@Beta
public final class DiscreteDomains {
private DiscreteDomains() {}
/**
* Returns the discrete domain for values of type {@code Integer}.
*/
public static DiscreteDomain<Integer> integers() {
return IntegerDomain.INSTANCE;
}
private static final class IntegerDomain extends DiscreteDomain<Integer>
implements Serializable {
private static final IntegerDomain INSTANCE = new IntegerDomain();
@Override public Integer next(Integer value) {
int i = value;
return (i == Integer.MAX_VALUE) ? null : i + 1;
}
@Override public Integer previous(Integer value) {
int i = value;
return (i == Integer.MIN_VALUE) ? null : i - 1;
}
@Override public long distance(Integer start, Integer end) {
return (long) end - start;
}
@Override public Integer minValue() {
return Integer.MIN_VALUE;
}
@Override public Integer maxValue() {
return Integer.MAX_VALUE;
}
private Object readResolve() {
return INSTANCE;
}
private static final long serialVersionUID = 0;
}
/**
* Returns the discrete domain for values of type {@code Long}.
*/
public static DiscreteDomain<Long> longs() {
return LongDomain.INSTANCE;
}
private static final class LongDomain extends DiscreteDomain<Long>
implements Serializable {
private static final LongDomain INSTANCE = new LongDomain();
@Override public Long next(Long value) {
long l = value;
return (l == Long.MAX_VALUE) ? null : l + 1;
}
@Override public Long previous(Long value) {
long l = value;
return (l == Long.MIN_VALUE) ? null : l - 1;
}
@Override public long distance(Long start, Long end) {
long result = end - start;
if (end > start && result < 0) { // overflow
return Long.MAX_VALUE;
}
if (end < start && result > 0) { // underflow
return Long.MIN_VALUE;
}
return result;
}
@Override public Long minValue() {
return Long.MIN_VALUE;
}
@Override public Long maxValue() {
return Long.MAX_VALUE;
}
private Object readResolve() {
return INSTANCE;
}
private static final long serialVersionUID = 0;
}
/**
* Returns the discrete domain for values of type {@code BigInteger}.
*/
// TODO(kevinb): make sure it's tested, and make it public
static DiscreteDomain<BigInteger> bigIntegers() {
return BigIntegerDomain.INSTANCE;
}
private static final class BigIntegerDomain extends DiscreteDomain<BigInteger>
implements Serializable {
private static final BigIntegerDomain INSTANCE = new BigIntegerDomain();
private static final BigInteger MIN_LONG =
BigInteger.valueOf(Long.MIN_VALUE);
private static final BigInteger MAX_LONG =
BigInteger.valueOf(Long.MAX_VALUE);
@Override public BigInteger next(BigInteger value) {
return value.add(BigInteger.ONE);
}
@Override public BigInteger previous(BigInteger value) {
return value.subtract(BigInteger.ONE);
}
@Override public long distance(BigInteger start, BigInteger end) {
return start.subtract(end).max(MIN_LONG).min(MAX_LONG).longValue();
}
private Object readResolve() {
return INSTANCE;
}
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.collect;
import com.google.common.annotations.Beta;
/**
* Provides equivalent behavior to {@link String#intern} for other immutable
* types.
*
* @author Kevin Bourrillion
* @since 3.0
*/
@Beta
public interface Interner<E> {
/**
* Chooses and returns the representative instance for any of a collection of
* instances that are equal to each other. If two {@linkplain Object#equals
* equal} inputs are given to this method, both calls will return the same
* instance. That is, {@code intern(a).equals(a)} always holds, and {@code
* intern(a) == intern(b)} if and only if {@code a.equals(b)}. Note that
* {@code intern(a)} is permitted to return one instance now and a different
* instance later if the original interned instance was garbage-collected.
*
* <p><b>Warning:</b> do not use with mutable objects.
*
* @throws NullPointerException if {@code sample} is null
*/
E intern(E sample);
}
| 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 static com.google.common.base.Preconditions.checkNotNull;
import java.util.Comparator;
import java.util.Map;
import java.util.Map.Entry;
import java.util.SortedMap;
import javax.annotation.Nullable;
import com.google.common.annotations.Beta;
import com.google.common.annotations.GwtCompatible;
import com.google.common.annotations.GwtIncompatible;
import com.google.common.base.Function;
import com.google.common.base.Predicate;
import com.google.common.base.Predicates;
import com.google.common.collect.Maps.EntryTransformer;
/**
* Static utility methods pertaining to {@link SortedMap} instances.
*
* @author Louis Wasserman
* @since 8.0
* @deprecated Use the identical methods in {@link Maps}. This class is
* scheduled for deletion from Guava in Guava release 12.0.
*/
@Beta
@Deprecated
@GwtCompatible
public final class SortedMaps {
private SortedMaps() {}
/**
* 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.
*
* @deprecated Use {@link Maps#transformValues(SortedMap, Function)}
*/
@Deprecated public static <K, V1, V2> SortedMap<K, V2> transformValues(
SortedMap<K, V1> fromMap, final Function<? super V1, V2> function) {
return Maps.transformValues(fromMap, function);
}
/**
* 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.
*
* @deprecated Use {@link Maps#transformEntries(SortedMap, EntryTransformer)}
*/
@Deprecated public static <K, V1, V2> SortedMap<K, V2> transformEntries(
final SortedMap<K, V1> fromMap,
EntryTransformer<? super K, ? super V1, V2> transformer) {
return Maps.transformEntries(fromMap, transformer);
}
/**
* 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
* @deprecated Use {@link Maps#difference(SortedMap, Map)}
*/
@Deprecated public static <K, V> SortedMapDifference<K, V> difference(
SortedMap<K, ? extends V> left, Map<? extends K, ? extends V> right) {
return Maps.difference(left, right);
}
/**
* 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 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.
*/
@GwtIncompatible("untested")
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 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.
*/
@GwtIncompatible("untested")
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 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}.
*/
@GwtIncompatible("untested")
public static <K, V> SortedMap<K, V> filterEntries(
SortedMap<K, V> unfiltered,
Predicate<? super Entry<K, V>> entryPredicate) {
checkNotNull(entryPredicate);
return (unfiltered instanceof FilteredSortedMap)
? filterFiltered((FilteredSortedMap<K, V>) unfiltered, entryPredicate)
: new FilteredSortedMap<K, V>(checkNotNull(unfiltered), entryPredicate);
}
/**
* Support {@code clear()}, {@code removeAll()}, and {@code retainAll()} when
* filtering a filtered sorted map.
*/
private static <K, V> SortedMap<K, V> filterFiltered(
FilteredSortedMap<K, V> map,
Predicate<? super Entry<K, V>> entryPredicate) {
Predicate<Entry<K, V>> predicate
= Predicates.and(map.predicate, entryPredicate);
return new FilteredSortedMap<K, V>(map.sortedMap(), predicate);
}
private static class FilteredSortedMap<K, V>
extends Maps.FilteredEntryMap<K, V> implements SortedMap<K, V> {
FilteredSortedMap(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 FilteredSortedMap<K, V>(sortedMap().headMap(toKey), predicate);
}
@Override public SortedMap<K, V> subMap(K fromKey, K toKey) {
return new FilteredSortedMap<K, V>(
sortedMap().subMap(fromKey, toKey), predicate);
}
@Override public SortedMap<K, V> tailMap(K fromKey) {
return new FilteredSortedMap<K, V>(
sortedMap().tailMap(fromKey), predicate);
}
}
}
| 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.Beta;
import com.google.common.annotations.GwtCompatible;
import java.util.Collection;
import java.util.Comparator;
import java.util.Iterator;
import java.util.SortedSet;
/**
* A {@link 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 Collection} contract, which it 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
* @since 11.0
*/
@Beta
@GwtCompatible
public interface SortedMultiset<E> extends Multiset<E>, SortedIterable<E> {
/**
* Returns the comparator that orders this multiset, or
* {@link Ordering#natural()} if the natural ordering of the elements is used.
*/
Comparator<? super E> comparator();
/**
* Returns the entry of the first element in this multiset, or {@code null} if
* this multiset is empty.
*/
Entry<E> firstEntry();
/**
* Returns the entry of the last element in this multiset, or {@code null} if
* this multiset is empty.
*/
Entry<E> lastEntry();
/**
* Returns and removes the entry associated with the lowest element in this
* multiset, or returns {@code null} if this multiset is empty.
*/
Entry<E> pollFirstEntry();
/**
* Returns and removes the entry associated with the greatest element in this
* multiset, or returns {@code null} if this multiset is empty.
*/
Entry<E> pollLastEntry();
/**
* Returns a {@link SortedSet} view of the distinct elements in this multiset.
*/
@Override SortedSet<E> elementSet();
/**
* {@inheritDoc}
*
* <p>The iterator returns the elements in ascending order according to this
* multiset's comparator.
*/
@Override Iterator<E> iterator();
/**
* Returns a descending view of this multiset. Modifications made to either
* map will be reflected in the other.
*/
SortedMultiset<E> descendingMultiset();
/**
* Returns a view of this multiset restricted to the elements less than
* {@code upperBound}, optionally including {@code upperBound} itself. The
* returned multiset is a view of this multiset, so changes to one will be
* reflected in the other. The returned multiset supports all operations that
* this multiset supports.
*
* <p>The returned multiset will throw an {@link IllegalArgumentException} on
* attempts to add elements outside its range.
*/
SortedMultiset<E> headMultiset(E upperBound, BoundType boundType);
/**
* Returns a view of this multiset restricted to the range between
* {@code lowerBound} and {@code upperBound}. The returned multiset is a view
* of this multiset, so changes to one will be reflected in the other. The
* returned multiset supports all operations that this multiset supports.
*
* <p>The returned multiset will throw an {@link IllegalArgumentException} on
* attempts to add elements outside its range.
*
* <p>This method is equivalent to
* {@code tailMultiset(lowerBound, lowerBoundType).headMultiset(upperBound,
* upperBoundType)}.
*/
SortedMultiset<E> subMultiset(E lowerBound, BoundType lowerBoundType,
E upperBound, BoundType upperBoundType);
/**
* Returns a view of this multiset restricted to the elements greater than
* {@code lowerBound}, optionally including {@code lowerBound} itself. The
* returned multiset is a view of this multiset, so changes to one will be
* reflected in the other. The returned multiset supports all operations that
* this multiset supports.
*
* <p>The returned multiset will throw an {@link IllegalArgumentException} on
* attempts to add elements outside its range.
*/
SortedMultiset<E> tailMultiset(E lowerBound, BoundType boundType);
}
| 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.Beta;
import com.google.common.annotations.GwtCompatible;
import java.util.Set;
import javax.annotation.Nullable;
/**
* A set which forwards all its method calls to another set. Subclasses should
* override one or more methods to modify the behavior of the backing set as
* desired per the <a
* href="http://en.wikipedia.org/wiki/Decorator_pattern">decorator pattern</a>.
*
* <p><b>Warning:</b> The methods of {@code ForwardingSet} forward
* <b>indiscriminately</b> to the methods of the delegate. For example,
* overriding {@link #add} alone <b>will not</b> change the behavior of {@link
* #addAll}, which can lead to unexpected behavior. In this case, you should
* override {@code addAll} as well, either providing your own implementation, or
* delegating to the provided {@code standardAddAll} method.
*
* <p>The {@code standard} methods are not guaranteed to be thread-safe, even
* when all of the methods that they depend on are thread-safe.
*
* @author Kevin Bourrillion
* @author Louis Wasserman
* @since 2.0 (imported from Google Collections Library)
*/
@GwtCompatible
public abstract class ForwardingSet<E> extends ForwardingCollection<E>
implements Set<E> {
// TODO(user): identify places where thread safety is actually lost
/** Constructor for use by subclasses. */
protected ForwardingSet() {}
@Override protected abstract Set<E> delegate();
@Override public boolean equals(@Nullable Object object) {
return object == this || delegate().equals(object);
}
@Override public int hashCode() {
return delegate().hashCode();
}
/**
* A sensible definition of {@link #equals} in terms of {@link #size} and
* {@link #containsAll}. If you override either of those methods, you may wish
* to override {@link #equals} to forward to this implementation.
*
* @since 7.0
*/
@Beta protected boolean standardEquals(@Nullable Object object) {
return Sets.equalsImpl(this, object);
}
/**
* A sensible definition of {@link #hashCode} in terms of {@link #iterator}.
* If you override {@link #iterator}, you may wish to override {@link #equals}
* to forward to this implementation.
*
* @since 7.0
*/
@Beta protected int standardHashCode() {
return Sets.hashCodeImpl(this);
}
}
| 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 java.util.Map;
import java.util.Set;
import javax.annotation.Nullable;
/**
* A {@code Multimap} that cannot hold duplicate key-value pairs. Adding a
* key-value pair that's already in the multimap has no effect.
*
* <p>The {@link #get}, {@link #removeAll}, and {@link #replaceValues} methods
* each return a {@link Set} of values, while {@link #entries} returns a {@code
* Set} of map entries. Though the method signature doesn't say so explicitly,
* the map returned by {@link #asMap} has {@code Set} values.
*
* <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
public interface SetMultimap<K, V> extends Multimap<K, V> {
/**
* {@inheritDoc}
*
* <p>Because a {@code SetMultimap} has unique values for a given key, this
* method returns a {@link Set}, instead of the {@link java.util.Collection}
* specified in the {@link Multimap} interface.
*/
@Override
Set<V> get(@Nullable K key);
/**
* {@inheritDoc}
*
* <p>Because a {@code SetMultimap} has unique values for a given key, this
* method returns a {@link Set}, instead of the {@link java.util.Collection}
* specified in the {@link Multimap} interface.
*/
@Override
Set<V> removeAll(@Nullable Object key);
/**
* {@inheritDoc}
*
* <p>Because a {@code SetMultimap} has unique values for a given key, this
* method returns a {@link Set}, instead of the {@link java.util.Collection}
* specified in the {@link Multimap} interface.
*
* <p>Any duplicates in {@code values} will be stored in the multimap once.
*/
@Override
Set<V> replaceValues(K key, Iterable<? extends V> values);
/**
* {@inheritDoc}
*
* <p>Because a {@code SetMultimap} has unique values for a given key, this
* method returns a {@link Set}, instead of the {@link java.util.Collection}
* specified in the {@link Multimap} interface.
*/
@Override
Set<Map.Entry<K, V>> entries();
/**
* {@inheritDoc}
*
* <p>Though the method signature doesn't say so explicitly, the returned map
* has {@link Set} values.
*/
@Override
Map<K, Collection<V>> asMap();
/**
* Compares the specified object to this multimap for equality.
*
* <p>Two {@code SetMultimap} instances are equal if, for each key, they
* contain the same values. Equality does not depend on the ordering of keys
* or values.
*
* <p>An empty {@code SetMultimap} is equal to any other empty {@code
* Multimap}, including an empty {@code ListMultimap}.
*/
@Override
boolean equals(@Nullable Object obj);
}
| 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 com.google.common.annotations.VisibleForTesting;
import com.google.common.primitives.Ints;
import java.io.Serializable;
import java.util.ArrayList;
import java.util.Collection;
import java.util.Collections;
import java.util.HashSet;
import java.util.Iterator;
import java.util.Set;
import javax.annotation.Nullable;
/**
* A high-performance, immutable {@code Set} with reliable, user-specified
* iteration order. Does not permit null elements.
*
* <p>Unlike {@link Collections#unmodifiableSet}, which is a <i>view</i> of a
* separate collection that can still change, an instance of this class contains
* its own private data and will <i>never</i> change. This class is convenient
* for {@code public static final} sets ("constant sets") and also lets you
* easily make a "defensive copy" of a set provided to your class by a caller.
*
* <p><b>Warning:</b> Like most sets, an {@code ImmutableSet} will not function
* correctly if an element is modified after being placed in the set. For this
* reason, and to avoid general confusion, it is strongly recommended to place
* only immutable objects into this collection.
*
* <p>This class has been observed to perform significantly better than {@link
* HashSet} for objects with very fast {@link Object#hashCode} implementations
* (as a well-behaved immutable object should). While this class's factory
* methods create hash-based instances, the {@link ImmutableSortedSet} subclass
* performs binary searches instead.
*
* <p><b>Note:</b> Although this class is not final, it cannot be subclassed
* outside its package as it has no public or protected constructors. Thus,
* instances of this type 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>.
*
* @see ImmutableList
* @see ImmutableMap
* @author Kevin Bourrillion
* @author Nick Kralevich
* @since 2.0 (imported from Google Collections Library)
*/
@GwtCompatible(serializable = true, emulated = true)
@SuppressWarnings("serial") // we're overriding default serialization
public abstract class ImmutableSet<E> extends ImmutableCollection<E>
implements Set<E> {
/**
* Returns the empty immutable set. This set behaves and performs comparably
* to {@link Collections#emptySet}, and is preferable mainly for consistency
* and maintainability of your code.
*/
// Casting to any type is safe because the set will never hold any elements.
@SuppressWarnings({"unchecked"})
public static <E> ImmutableSet<E> of() {
return (ImmutableSet<E>) EmptyImmutableSet.INSTANCE;
}
/**
* Returns an immutable set containing a single element. This set behaves and
* performs comparably to {@link Collections#singleton}, but will not accept
* a null element. It is preferable mainly for consistency and
* maintainability of your code.
*/
public static <E> ImmutableSet<E> of(E element) {
return new SingletonImmutableSet<E>(element);
}
/**
* Returns an immutable set containing the given elements, in order. Repeated
* occurrences of an element (according to {@link Object#equals}) after the
* first are ignored.
*
* @throws NullPointerException if any element is null
*/
public static <E> ImmutableSet<E> of(E e1, E e2) {
return construct(e1, e2);
}
/**
* Returns an immutable set containing the given elements, in order. Repeated
* occurrences of an element (according to {@link Object#equals}) after the
* first are ignored.
*
* @throws NullPointerException if any element is null
*/
public static <E> ImmutableSet<E> of(E e1, E e2, E e3) {
return construct(e1, e2, e3);
}
/**
* Returns an immutable set containing the given elements, in order. Repeated
* occurrences of an element (according to {@link Object#equals}) after the
* first are ignored.
*
* @throws NullPointerException if any element is null
*/
public static <E> ImmutableSet<E> of(E e1, E e2, E e3, E e4) {
return construct(e1, e2, e3, e4);
}
/**
* Returns an immutable set containing the given elements, in order. Repeated
* occurrences of an element (according to {@link Object#equals}) after the
* first are ignored.
*
* @throws NullPointerException if any element is null
*/
public static <E> ImmutableSet<E> of(E e1, E e2, E e3, E e4, E e5) {
return construct(e1, e2, e3, e4, e5);
}
/**
* Returns an immutable set containing the given elements, in order. Repeated
* occurrences of an element (according to {@link Object#equals}) after the
* first are ignored.
*
* @throws NullPointerException if any element is null
* @since 3.0 (source-compatible since 2.0)
*/
public static <E> ImmutableSet<E> of(E e1, E e2, E e3, E e4, E e5, E e6,
E... others) {
final int paramCount = 6;
Object[] elements = new Object[paramCount + others.length];
elements[0] = e1;
elements[1] = e2;
elements[2] = e3;
elements[3] = e4;
elements[4] = e5;
elements[5] = e6;
for (int i = paramCount; i < elements.length; i++) {
elements[i] = others[i - paramCount];
}
return construct(elements);
}
/** {@code elements} has to be internally created array. */
private static <E> ImmutableSet<E> construct(Object... elements) {
int tableSize = chooseTableSize(elements.length);
Object[] table = new Object[tableSize];
int mask = tableSize - 1;
ArrayList<Object> uniqueElementsList = null;
int hashCode = 0;
for (int i = 0; i < elements.length; i++) {
Object element = elements[i];
int hash = element.hashCode();
for (int j = Hashing.smear(hash); ; j++) {
int index = j & mask;
Object value = table[index];
if (value == null) {
if (uniqueElementsList != null) {
uniqueElementsList.add(element);
}
// Came to an empty slot. Put the element here.
table[index] = element;
hashCode += hash;
break;
} else if (value.equals(element)) {
if (uniqueElementsList == null) {
// first dup
uniqueElementsList = new ArrayList<Object>(elements.length);
for (int k = 0; k < i; k++) {
Object previous = elements[k];
uniqueElementsList.add(previous);
}
}
break;
}
}
}
Object[] uniqueElements = uniqueElementsList == null
? elements
: uniqueElementsList.toArray();
if (uniqueElements.length == 1) {
// There is only one element or elements are all duplicates
@SuppressWarnings("unchecked") // we are careful to only pass in E
E element = (E) uniqueElements[0];
return new SingletonImmutableSet<E>(element, hashCode);
} else if (tableSize != chooseTableSize(uniqueElements.length)) {
// Resize the table when the array includes too many duplicates.
// when this happens, we have already made a copy
return construct(uniqueElements);
} else {
return new RegularImmutableSet<E>(uniqueElements, hashCode, table, mask);
}
}
// We use power-of-2 tables, and this is the highest int that's a power of 2
static final int MAX_TABLE_SIZE = Ints.MAX_POWER_OF_TWO;
// Represents how tightly we can pack things, as a maximum.
private static final double DESIRED_LOAD_FACTOR = 0.7;
// If the set has this many elements, it will "max out" the table size
private static final int CUTOFF = (int) Math.floor(MAX_TABLE_SIZE * DESIRED_LOAD_FACTOR);
/**
* Returns an array size suitable for the backing array of a hash table that
* uses open addressing with linear probing in its implementation. The
* returned size is the smallest power of two that can hold setSize elements
* with the desired load factor.
*
* <p>Do not call this method with setSize < 2.
*/
@VisibleForTesting static int chooseTableSize(int setSize) {
// Correct the size for open addressing to match desired load factor.
if (setSize < CUTOFF) {
// Round up to the next highest power of 2.
int tableSize = Integer.highestOneBit(setSize - 1) << 1;
while (tableSize * DESIRED_LOAD_FACTOR < setSize) {
tableSize <<= 1;
}
return tableSize;
}
// The table can't be completely full or we'll get infinite reprobes
checkArgument(setSize < MAX_TABLE_SIZE, "collection too large");
return MAX_TABLE_SIZE;
}
/**
* Returns an immutable set containing the given elements, in order. Repeated
* occurrences of an element (according to {@link Object#equals}) after the
* first are ignored.
*
* @throws NullPointerException if any of {@code elements} is null
* @since 3.0
*/
public static <E> ImmutableSet<E> copyOf(E[] elements) {
// TODO(benyu): could we delegate to
// copyFromCollection(Arrays.asList(elements))?
switch (elements.length) {
case 0:
return of();
case 1:
return of(elements[0]);
default:
return construct(elements.clone());
}
}
/**
* Returns an immutable set containing the given elements, in order. Repeated
* occurrences of an element (according to {@link Object#equals}) after the
* first are ignored. This method iterates over {@code elements} at most once.
*
* <p>Note that if {@code s} is a {@code Set<String>}, then {@code
* ImmutableSet.copyOf(s)} returns an {@code ImmutableSet<String>} containing
* each of the strings in {@code s}, while {@code ImmutableSet.of(s)} returns
* a {@code ImmutableSet<Set<String>>} containing one element (the given set
* itself).
*
* <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 of {@code elements} is null
*/
public static <E> ImmutableSet<E> copyOf(Iterable<? extends E> elements) {
return (elements instanceof Collection)
? copyOf(Collections2.cast(elements))
: copyOf(elements.iterator());
}
/**
* Returns an immutable set containing the given elements, in order. Repeated
* occurrences of an element (according to {@link Object#equals}) after the
* first are ignored.
*
* @throws NullPointerException if any of {@code elements} is null
*/
public static <E> ImmutableSet<E> copyOf(Iterator<? extends E> elements) {
// TODO(benyu): here we could avoid toArray() for 0 or 1-element list,
// worth it?
return copyFromCollection(Lists.newArrayList(elements));
}
/**
* Returns an immutable set containing the given elements, in order. Repeated
* occurrences of an element (according to {@link Object#equals}) after the
* first are ignored. This method iterates over {@code elements} at most
* once.
*
* <p>Note that if {@code s} is a {@code Set<String>}, then {@code
* ImmutableSet.copyOf(s)} returns an {@code ImmutableSet<String>} containing
* each of the strings in {@code s}, while {@code ImmutableSet.of(s)} returns
* a {@code ImmutableSet<Set<String>>} containing one element (the given set
* itself).
*
* <p><b>Note:</b> Despite what the method name suggests, {@code copyOf} will
* return constant-space views, rather than linear-space copies, of some
* inputs known to be immutable. For some other immutable inputs, such as key
* sets of an {@code ImmutableMap}, it still performs a copy in order to avoid
* holding references to the values of the map. The heuristics used in this
* decision are undocumented and subject to change except that:
* <ul>
* <li>A full copy will be done of any {@code ImmutableSortedSet}.</li>
* <li>{@code ImmutableSet.copyOf()} is idempotent with respect to pointer
* equality.</li>
* </ul>
*
* <p>This method is safe to use even when {@code elements} is a synchronized
* or concurrent collection that is currently being modified by another
* thread.
*
* @throws NullPointerException if any of {@code elements} is null
* @since 7.0 (source-compatible since 2.0)
*/
public static <E> ImmutableSet<E> copyOf(Collection<? extends E> elements) {
if (elements instanceof ImmutableSet
&& !(elements instanceof ImmutableSortedSet)) {
@SuppressWarnings("unchecked") // all supported methods are covariant
ImmutableSet<E> set = (ImmutableSet<E>) elements;
if (!set.isPartialView()) {
return set;
}
}
return copyFromCollection(elements);
}
private static <E> ImmutableSet<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
E onlyElement = (E) elements[0];
return of(onlyElement);
default:
// safe to use the array without copying it
// as specified by Collection.toArray().
return construct(elements);
}
}
ImmutableSet() {}
/** Returns {@code true} if the {@code hashCode()} method runs quickly. */
boolean isHashCodeFast() {
return false;
}
@Override public boolean equals(@Nullable Object object) {
if (object == this) {
return true;
}
if (object instanceof ImmutableSet
&& isHashCodeFast()
&& ((ImmutableSet<?>) object).isHashCodeFast()
&& hashCode() != object.hashCode()) {
return false;
}
return Sets.equalsImpl(this, object);
}
@Override public int hashCode() {
return Sets.hashCodeImpl(this);
}
// This declaration is needed to make Set.iterator() and
// ImmutableCollection.iterator() consistent.
@Override public abstract UnmodifiableIterator<E> iterator();
abstract static class ArrayImmutableSet<E> extends ImmutableSet<E> {
// the elements (two or more) in the desired order.
final transient Object[] elements;
ArrayImmutableSet(Object[] elements) {
this.elements = elements;
}
@Override
public int size() {
return elements.length;
}
@Override public boolean isEmpty() {
return false;
}
/*
* The cast is safe because the only way to create an instance is via the
* create() method above, which only permits elements of type E.
*/
@SuppressWarnings("unchecked")
@Override public UnmodifiableIterator<E> iterator() {
return (UnmodifiableIterator<E>) Iterators.forArray(elements);
}
@Override public Object[] toArray() {
Object[] array = new Object[size()];
System.arraycopy(elements, 0, array, 0, size());
return array;
}
@Override public <T> T[] toArray(T[] array) {
int size = size();
if (array.length < size) {
array = ObjectArrays.newArray(array, size);
} else if (array.length > size) {
array[size] = null;
}
System.arraycopy(elements, 0, array, 0, size);
return array;
}
@Override public boolean containsAll(Collection<?> targets) {
if (targets == this) {
return true;
}
if (!(targets instanceof ArrayImmutableSet)) {
return super.containsAll(targets);
}
if (targets.size() > size()) {
return false;
}
for (Object target : ((ArrayImmutableSet<?>) targets).elements) {
if (!contains(target)) {
return false;
}
}
return true;
}
@Override boolean isPartialView() {
return false;
}
@Override ImmutableList<E> createAsList() {
return new ImmutableAsList<E>(elements, this);
}
}
/** such as ImmutableMap.keySet() */
abstract static class TransformedImmutableSet<D, E> extends ImmutableSet<E> {
final D[] source;
final int hashCode;
TransformedImmutableSet(D[] source, int hashCode) {
this.source = source;
this.hashCode = hashCode;
}
abstract E transform(D element);
@Override
public int size() {
return source.length;
}
@Override public boolean isEmpty() {
return false;
}
@Override public UnmodifiableIterator<E> iterator() {
return new AbstractIndexedListIterator<E>(source.length) {
@Override protected E get(int index) {
return transform(source[index]);
}
};
}
@Override public Object[] toArray() {
return toArray(new Object[size()]);
}
@Override public <T> T[] toArray(T[] array) {
int size = size();
if (array.length < size) {
array = ObjectArrays.newArray(array, size);
} else if (array.length > size) {
array[size] = null;
}
// Writes will produce ArrayStoreException when the toArray() doc requires
Object[] objectArray = array;
for (int i = 0; i < source.length; i++) {
objectArray[i] = transform(source[i]);
}
return array;
}
@Override public final int hashCode() {
return hashCode;
}
@Override boolean isHashCodeFast() {
return true;
}
}
/*
* This class is used to serialize all ImmutableSet instances, except for
* ImmutableEnumSet/ImmutableSortedSet, regardless of implementation type. It
* captures their "logical contents" and they are reconstructed using public
* static factories. This is necessary to ensure that the existence of a
* particular implementation type is an implementation detail.
*/
private static class SerializedForm implements Serializable {
final Object[] elements;
SerializedForm(Object[] elements) {
this.elements = elements;
}
Object readResolve() {
return copyOf(elements);
}
private static final long serialVersionUID = 0;
}
@Override Object writeReplace() {
return new SerializedForm(toArray());
}
/**
* Returns a new builder. The generated builder is equivalent to the builder
* created by the {@link Builder} constructor.
*/
public static <E> Builder<E> builder() {
return new Builder<E>();
}
/**
* A builder for creating immutable set instances, especially {@code public
* static final} sets ("constant sets"). Example: <pre> {@code
*
* public static final ImmutableSet<Color> GOOGLE_COLORS =
* new ImmutableSet.Builder<Color>()
* .addAll(WEBSAFE_COLORS)
* .add(new Color(0, 191, 255))
* .build();}</pre>
*
* Builder instances can be reused; it is safe to call {@link #build} multiple
* times to build multiple sets in series. Each set is a superset of the set
* created before it.
*
* @since 2.0 (imported from Google Collections Library)
*/
public static class Builder<E> extends ImmutableCollection.Builder<E> {
// accessed directly by ImmutableSortedSet
final ArrayList<E> contents = Lists.newArrayList();
/**
* Creates a new builder. The returned builder is equivalent to the builder
* generated by {@link ImmutableSet#builder}.
*/
public Builder() {}
/**
* Adds {@code element} to the {@code ImmutableSet}. If the {@code
* ImmutableSet} already contains {@code element}, then {@code add} has no
* effect (only the previously added element is retained).
*
* @param element the element to add
* @return this {@code Builder} object
* @throws NullPointerException if {@code element} is null
*/
@Override public Builder<E> add(E element) {
contents.add(checkNotNull(element));
return this;
}
/**
* Adds each element of {@code elements} to the {@code ImmutableSet},
* ignoring duplicate elements (only the first duplicate element is added).
*
* @param elements the elements to add
* @return this {@code Builder} object
* @throws NullPointerException if {@code elements} is null or contains a
* null element
*/
@Override public Builder<E> add(E... elements) {
contents.ensureCapacity(contents.size() + elements.length);
super.add(elements);
return this;
}
/**
* Adds each element of {@code elements} to the {@code ImmutableSet},
* ignoring duplicate elements (only the first duplicate element is added).
*
* @param elements the {@code Iterable} to add to the {@code ImmutableSet}
* @return this {@code Builder} object
* @throws NullPointerException if {@code elements} is null or contains a
* null element
*/
@Override public Builder<E> addAll(Iterable<? extends E> elements) {
if (elements instanceof Collection) {
Collection<?> collection = (Collection<?>) elements;
contents.ensureCapacity(contents.size() + collection.size());
}
super.addAll(elements);
return this;
}
/**
* Adds each element of {@code elements} to the {@code ImmutableSet},
* ignoring duplicate elements (only the first duplicate element is added).
*
* @param elements the elements to add to the {@code ImmutableSet}
* @return this {@code Builder} object
* @throws NullPointerException if {@code elements} is null or contains a
* null element
*/
@Override public Builder<E> addAll(Iterator<? extends E> elements) {
super.addAll(elements);
return this;
}
/**
* Returns a newly-created {@code ImmutableSet} based on the contents of
* the {@code Builder}.
*/
@Override public ImmutableSet<E> build() {
return copyOf(contents);
}
}
}
| 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 static com.google.common.base.Preconditions.checkNotNull;
import static com.google.common.collect.BstSide.LEFT;
import static com.google.common.collect.BstSide.RIGHT;
import com.google.common.annotations.GwtCompatible;
import java.util.Comparator;
import javax.annotation.Nullable;
/**
* Tools to perform single-key queries and mutations in binary search trees.
*
* @author Louis Wasserman
*/
@GwtCompatible
final class BstOperations {
private BstOperations() {}
/**
* Returns the node with key {@code key} in {@code tree}, if any.
*/
@Nullable
public static <K, N extends BstNode<K, N>> N seek(
Comparator<? super K> comparator, @Nullable N tree, @Nullable K key) {
checkNotNull(comparator);
if (tree == null) {
return null;
}
int cmp = comparator.compare(key, tree.getKey());
if (cmp == 0) {
return tree;
} else {
BstSide side = (cmp < 0) ? LEFT : RIGHT;
return seek(comparator, tree.childOrNull(side), key);
}
}
/**
* Returns the result of performing the mutation specified by {@code mutationRule} in {@code
* tree} at the location with key {@code key}.
*
* <ul>
* <li>If the returned {@link BstModificationResult} has type {@code IDENTITY}, the exact
* original tree is returned.
* <li>If the returned {@code BstModificationResult} has type {@code REBUILDING_CHANGE},
* the tree will be rebuilt with the node factory of the mutation rule, but not rebalanced.
* <li>If the returned {@code BstModificationResult} has type {@code REBALANCING_CHANGE},
* the tree will be rebalanced using the balance policy of the mutation rule.
* </ul>
*/
public static <K, N extends BstNode<K, N>> BstMutationResult<K, N> mutate(
Comparator<? super K> comparator, BstMutationRule<K, N> mutationRule, @Nullable N tree,
@Nullable K key) {
checkNotNull(comparator);
checkNotNull(mutationRule);
if (tree != null) {
int cmp = comparator.compare(key, tree.getKey());
if (cmp != 0) {
BstSide side = (cmp < 0) ? LEFT : RIGHT;
BstMutationResult<K, N> mutation =
mutate(comparator, mutationRule, tree.childOrNull(side), key);
return mutation.lift(
tree, side, mutationRule.getNodeFactory(), mutationRule.getBalancePolicy());
}
}
return modify(tree, key, mutationRule);
}
/**
* Perform the local mutation at the tip of the specified path.
*/
public static <K, N extends BstNode<K, N>> BstMutationResult<K, N> mutate(
BstInOrderPath<N> path, BstMutationRule<K, N> mutationRule) {
checkNotNull(path);
checkNotNull(mutationRule);
BstBalancePolicy<N> balancePolicy = mutationRule.getBalancePolicy();
BstNodeFactory<N> nodeFactory = mutationRule.getNodeFactory();
N target = path.getTip();
K key = target.getKey();
BstMutationResult<K, N> result = modify(target, key, mutationRule);
while (path.hasPrefix()) {
BstInOrderPath<N> prefix = path.getPrefix();
result = result.lift(prefix.getTip(), path.getSideOfExtension(), nodeFactory, balancePolicy);
path = prefix;
}
return result;
}
/**
* Perform the local mutation right here, at the specified node.
*/
private static <K, N extends BstNode<K, N>> BstMutationResult<K, N> modify(
@Nullable N tree, K key, BstMutationRule<K, N> mutationRule) {
BstBalancePolicy<N> rebalancePolicy = mutationRule.getBalancePolicy();
BstNodeFactory<N> nodeFactory = mutationRule.getNodeFactory();
BstModifier<K, N> modifier = mutationRule.getModifier();
N originalRoot = tree;
N changedRoot;
N originalTarget = (tree == null) ? null : nodeFactory.createLeaf(tree);
BstModificationResult<N> modResult = modifier.modify(key, originalTarget);
N originalLeft = null;
N originalRight = null;
if (tree != null) {
originalLeft = tree.childOrNull(LEFT);
originalRight = tree.childOrNull(RIGHT);
}
switch (modResult.getType()) {
case IDENTITY:
changedRoot = tree;
break;
case REBUILDING_CHANGE:
if (modResult.getChangedTarget() != null) {
changedRoot =
nodeFactory.createNode(modResult.getChangedTarget(), originalLeft, originalRight);
} else if (tree == null) {
changedRoot = null;
} else {
throw new AssertionError(
"Modification result is a REBUILDING_CHANGE, but rebalancing required");
}
break;
case REBALANCING_CHANGE:
if (modResult.getChangedTarget() != null) {
changedRoot = rebalancePolicy.balance(
nodeFactory, modResult.getChangedTarget(), originalLeft, originalRight);
} else if (tree != null) {
changedRoot = rebalancePolicy.combine(nodeFactory, originalLeft, originalRight);
} else {
changedRoot = null;
}
break;
default:
throw new AssertionError();
}
return BstMutationResult.mutationResult(key, originalRoot, changedRoot, modResult);
}
/**
* Returns the result of removing the minimum element from the specified subtree.
*/
public static <K, N extends BstNode<K, N>> BstMutationResult<K, N> extractMin(
N root, BstNodeFactory<N> nodeFactory, BstBalancePolicy<N> balancePolicy) {
checkNotNull(root);
checkNotNull(nodeFactory);
checkNotNull(balancePolicy);
if (root.hasChild(LEFT)) {
BstMutationResult<K, N> subResult =
extractMin(root.getChild(LEFT), nodeFactory, balancePolicy);
return subResult.lift(root, LEFT, nodeFactory, balancePolicy);
}
return BstMutationResult.mutationResult(
root.getKey(), root, root.childOrNull(RIGHT),
BstModificationResult.rebalancingChange(root, null));
}
/**
* Returns the result of removing the maximum element from the specified subtree.
*/
public static <K, N extends BstNode<K, N>> BstMutationResult<K, N> extractMax(
N root, BstNodeFactory<N> nodeFactory, BstBalancePolicy<N> balancePolicy) {
checkNotNull(root);
checkNotNull(nodeFactory);
checkNotNull(balancePolicy);
if (root.hasChild(RIGHT)) {
BstMutationResult<K, N> subResult =
extractMax(root.getChild(RIGHT), nodeFactory, balancePolicy);
return subResult.lift(root, RIGHT, nodeFactory, balancePolicy);
}
return BstMutationResult.mutationResult(root.getKey(), root, root.childOrNull(LEFT),
BstModificationResult.rebalancingChange(root, null));
}
/**
* Inserts the specified entry into the tree as the minimum entry. Assumes that {@code
* entry.getKey()} is less than the key of all nodes in the subtree {@code root}.
*/
public static <N extends BstNode<?, N>> N insertMin(@Nullable N root, N entry,
BstNodeFactory<N> nodeFactory, BstBalancePolicy<N> balancePolicy) {
checkNotNull(entry);
checkNotNull(nodeFactory);
checkNotNull(balancePolicy);
if (root == null) {
return nodeFactory.createLeaf(entry);
} else {
return balancePolicy.balance(nodeFactory, root,
insertMin(root.childOrNull(LEFT), entry, nodeFactory, balancePolicy),
root.childOrNull(RIGHT));
}
}
/**
* Inserts the specified entry into the tree as the maximum entry. Assumes that {@code
* entry.getKey()} is greater than the key of all nodes in the subtree {@code root}.
*/
public static <N extends BstNode<?, N>> N insertMax(@Nullable N root, N entry,
BstNodeFactory<N> nodeFactory, BstBalancePolicy<N> balancePolicy) {
checkNotNull(entry);
checkNotNull(nodeFactory);
checkNotNull(balancePolicy);
if (root == null) {
return nodeFactory.createLeaf(entry);
} else {
return balancePolicy.balance(nodeFactory, root, root.childOrNull(LEFT),
insertMax(root.childOrNull(RIGHT), entry, nodeFactory, balancePolicy));
}
}
}
| 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.Beta;
import com.google.common.annotations.GwtIncompatible;
import com.google.common.base.Equivalences;
import com.google.common.base.Function;
import com.google.common.collect.MapMakerInternalMap.ReferenceEntry;
import java.util.concurrent.ConcurrentMap;
/**
* Contains static methods pertaining to instances of {@link Interner}.
*
* @author Kevin Bourrillion
* @since 3.0
*/
@Beta
public final class Interners {
private Interners() {}
/**
* Returns a new thread-safe interner which retains a strong reference to each instance it has
* interned, thus preventing these instances from being garbage-collected. If this retention is
* acceptable, this implementation may perform better than {@link #newWeakInterner}. Note that
* unlike {@link String#intern}, using this interner does not consume memory in the permanent
* generation.
*/
public static <E> Interner<E> newStrongInterner() {
final ConcurrentMap<E, E> map = new MapMaker().makeMap();
return new Interner<E>() {
@Override public E intern(E sample) {
E canonical = map.putIfAbsent(checkNotNull(sample), sample);
return (canonical == null) ? sample : canonical;
}
};
}
/**
* Returns a new thread-safe interner which retains a weak reference to each instance it has
* interned, and so does not prevent these instances from being garbage-collected. This most
* likely does not perform as well as {@link #newStrongInterner}, but is the best alternative
* when the memory usage of that implementation is unacceptable. Note that unlike {@link
* String#intern}, using this interner does not consume memory in the permanent generation.
*/
@GwtIncompatible("java.lang.ref.WeakReference")
public static <E> Interner<E> newWeakInterner() {
return new WeakInterner<E>();
}
private static class WeakInterner<E> implements Interner<E> {
// MapMaker is our friend, we know about this type
private final MapMakerInternalMap<E, Dummy> map = new MapMaker()
.weakKeys()
.keyEquivalence(Equivalences.equals())
.makeCustomMap();
@Override public E intern(E sample) {
while (true) {
// trying to read the canonical...
ReferenceEntry<E, Dummy> entry = map.getEntry(sample);
if (entry != null) {
E canonical = entry.getKey();
if (canonical != null) { // only matters if weak/soft keys are used
return canonical;
}
}
// didn't see it, trying to put it instead...
Dummy sneaky = map.putIfAbsent(sample, Dummy.VALUE);
if (sneaky == null) {
return sample;
} else {
/* Someone beat us to it! Trying again...
*
* Technically this loop not guaranteed to terminate, so theoretically (extremely
* unlikely) this thread might starve, but even then, there is always going to be another
* thread doing progress here.
*/
}
}
}
private enum Dummy { VALUE }
}
/**
* Returns a function that delegates to the {@link Interner#intern} method of the given interner.
*
* @since 8.0
*/
public static <E> Function<E, E> asFunction(Interner<E> interner) {
return new InternerFunction<E>(checkNotNull(interner));
}
private static class InternerFunction<E> implements Function<E, E> {
private final Interner<E> interner;
public InternerFunction(Interner<E> interner) {
this.interner = interner;
}
@Override public E apply(E input) {
return interner.intern(input);
}
@Override public int hashCode() {
return interner.hashCode();
}
@Override public boolean equals(Object other) {
if (other instanceof InternerFunction<?>) {
InternerFunction<?> that = (InternerFunction<?>) other;
return interner.equals(that.interner);
}
return false;
}
}
}
| 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 static com.google.common.base.Preconditions.checkNotNull;
import com.google.common.annotations.GwtCompatible;
import java.util.Comparator;
import java.util.Iterator;
import java.util.SortedSet;
/**
* This class provides a skeletal implementation of the {@link SortedMultiset} interface.
*
* <p>The {@link #count} and {@link #size} implementations all iterate across the set returned by
* {@link Multiset#entrySet()}, as do many methods acting on the set returned by
* {@link #elementSet()}. Override those methods for better performance.
*
* @author Louis Wasserman
*/
@GwtCompatible
abstract class AbstractSortedMultiset<E> extends AbstractMultiset<E> implements SortedMultiset<E> {
@GwtTransient final Comparator<? super E> comparator;
// needed for serialization
@SuppressWarnings("unchecked")
AbstractSortedMultiset() {
this((Comparator) Ordering.natural());
}
AbstractSortedMultiset(Comparator<? super E> comparator) {
this.comparator = checkNotNull(comparator);
}
@Override
public SortedSet<E> elementSet() {
return (SortedSet<E>) super.elementSet();
}
@Override
SortedSet<E> createElementSet() {
return new SortedMultisets.ElementSet<E>() {
@Override
SortedMultiset<E> multiset() {
return AbstractSortedMultiset.this;
}
};
}
@Override
public Comparator<? super E> comparator() {
return comparator;
}
@Override
public Entry<E> firstEntry() {
Iterator<Entry<E>> entryIterator = entryIterator();
return entryIterator.hasNext() ? entryIterator.next() : null;
}
@Override
public Entry<E> lastEntry() {
Iterator<Entry<E>> entryIterator = descendingEntryIterator();
return entryIterator.hasNext() ? entryIterator.next() : null;
}
@Override
public Entry<E> pollFirstEntry() {
Iterator<Entry<E>> entryIterator = entryIterator();
if (entryIterator.hasNext()) {
Entry<E> result = entryIterator.next();
result = Multisets.immutableEntry(result.getElement(), result.getCount());
entryIterator.remove();
return result;
}
return null;
}
@Override
public Entry<E> pollLastEntry() {
Iterator<Entry<E>> entryIterator = descendingEntryIterator();
if (entryIterator.hasNext()) {
Entry<E> result = entryIterator.next();
result = Multisets.immutableEntry(result.getElement(), result.getCount());
entryIterator.remove();
return result;
}
return null;
}
@Override
public SortedMultiset<E> subMultiset(E fromElement, BoundType fromBoundType, E toElement,
BoundType toBoundType) {
return tailMultiset(fromElement, fromBoundType).headMultiset(toElement, toBoundType);
}
abstract Iterator<Entry<E>> descendingEntryIterator();
Iterator<E> descendingIterator() {
return Multisets.iteratorImpl(descendingMultiset());
}
private transient SortedMultiset<E> descendingMultiset;
@Override
public SortedMultiset<E> descendingMultiset() {
SortedMultiset<E> result = descendingMultiset;
return (result == null) ? descendingMultiset = createDescendingMultiset() : result;
}
SortedMultiset<E> createDescendingMultiset() {
return new SortedMultisets.DescendingMultiset<E>() {
@Override
SortedMultiset<E> forwardMultiset() {
return AbstractSortedMultiset.this;
}
@Override
Iterator<Entry<E>> entryIterator() {
return descendingEntryIterator();
}
@Override
public Iterator<E> iterator() {
return descendingIterator();
}
};
}
}
| 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.GwtIncompatible;
import java.io.IOException;
import java.io.ObjectInputStream;
import java.io.ObjectOutputStream;
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)));
}
/**
* @serialData the number of distinct elements, the first element, its count,
* the second element, its count, and so on
*/
@GwtIncompatible("java.io.ObjectOutputStream")
private void writeObject(ObjectOutputStream stream) throws IOException {
stream.defaultWriteObject();
Serialization.writeMultiset(this, stream);
}
@GwtIncompatible("java.io.ObjectInputStream")
private void readObject(ObjectInputStream stream)
throws IOException, ClassNotFoundException {
stream.defaultReadObject();
int distinctElements = Serialization.readCount(stream);
setBackingMap(new LinkedHashMap<E, Count>(
Maps.capacity(distinctElements)));
Serialization.populateMultiset(this, stream, distinctElements);
}
@GwtIncompatible("not needed in emulated source")
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 com.google.common.annotations.GwtCompatible;
import java.io.InvalidObjectException;
import java.io.ObjectInputStream;
import java.io.Serializable;
/**
* List returned by {@link ImmutableCollection#asList} when the collection isn't
* an {@link ImmutableList} or an {@link ImmutableSortedSet}.
*
* @author Jared Levy
*/
@GwtCompatible(serializable = true, emulated = true)
@SuppressWarnings("serial")
final class ImmutableAsList<E> extends RegularImmutableList<E> {
private final transient ImmutableCollection<E> collection;
ImmutableAsList(Object[] array, ImmutableCollection<E> collection) {
super(array, 0, array.length);
this.collection = collection;
}
@Override public boolean contains(Object target) {
// The collection's contains() is at least as fast as RegularImmutableList's
// and is often faster.
return collection.contains(target);
}
/**
* Serialized form that leads to the same performance as the original list.
*/
static class SerializedForm implements Serializable {
final ImmutableCollection<?> collection;
SerializedForm(ImmutableCollection<?> collection) {
this.collection = collection;
}
Object readResolve() {
return collection.asList();
}
private static final long serialVersionUID = 0;
}
private void readObject(ObjectInputStream stream)
throws InvalidObjectException {
throw new InvalidObjectException("Use SerializedForm");
}
@Override Object writeReplace() {
return new SerializedForm(collection);
}
}
| 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 com.google.common.annotations.GwtIncompatible;
import java.io.IOException;
import java.io.InvalidObjectException;
import java.io.ObjectInputStream;
import java.io.ObjectOutputStream;
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;
}
/**
* @serialData number of distinct keys, and then for each distinct key: the
* key, the number of values for that key, and the key's values
*/
@GwtIncompatible("java.io.ObjectOutputStream")
private void writeObject(ObjectOutputStream stream) throws IOException {
stream.defaultWriteObject();
Serialization.writeMultimap(this, stream);
}
@GwtIncompatible("java.io.ObjectInputStream")
private void readObject(ObjectInputStream stream)
throws IOException, ClassNotFoundException {
stream.defaultReadObject();
int keyCount = stream.readInt();
if (keyCount < 0) {
throw new InvalidObjectException("Invalid key count " + keyCount);
}
ImmutableMap.Builder<Object, ImmutableSet<Object>> builder
= ImmutableMap.builder();
int tmpSize = 0;
for (int i = 0; i < keyCount; i++) {
Object key = stream.readObject();
int valueCount = stream.readInt();
if (valueCount <= 0) {
throw new InvalidObjectException("Invalid value count " + valueCount);
}
Object[] array = new Object[valueCount];
for (int j = 0; j < valueCount; j++) {
array[j] = stream.readObject();
}
ImmutableSet<Object> valueSet = ImmutableSet.copyOf(array);
if (valueSet.size() != array.length) {
throw new InvalidObjectException(
"Duplicate key-value pairs exist for key " + key);
}
builder.put(key, valueSet);
tmpSize += valueCount;
}
ImmutableMap<Object, ImmutableSet<Object>> tmpMap;
try {
tmpMap = builder.build();
} catch (IllegalArgumentException e) {
throw (InvalidObjectException)
new InvalidObjectException(e.getMessage()).initCause(e);
}
FieldSettersHolder.MAP_FIELD_SETTER.set(this, tmpMap);
FieldSettersHolder.SIZE_FIELD_SETTER.set(this, tmpSize);
}
@GwtIncompatible("not needed in emulated source.")
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.collect;
import com.google.common.annotations.GwtCompatible;
import java.util.Iterator;
/**
* An iterator which forwards all its method calls to another iterator.
* Subclasses should override one or more methods to modify the behavior of the
* backing iterator as desired per the <a
* href="http://en.wikipedia.org/wiki/Decorator_pattern">decorator pattern</a>.
*
* @author Kevin Bourrillion
* @since 2.0 (imported from Google Collections Library)
*/
@GwtCompatible
public abstract class ForwardingIterator<T>
extends ForwardingObject implements Iterator<T> {
/** Constructor for use by subclasses. */
protected ForwardingIterator() {}
@Override protected abstract Iterator<T> delegate();
@Override
public boolean hasNext() {
return delegate().hasNext();
}
@Override
public T next() {
return delegate().next();
}
@Override
public void remove() {
delegate().remove();
}
}
| 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.annotations.GwtIncompatible;
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.HashSet;
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
* @param type the type of the elements
* @return a newly-allocated array into which all the elements of the iterable
* have been copied
*/
@GwtIncompatible("Array.newInstance(Class, int)")
public static <T> T[] toArray(Iterable<? extends T> iterable, Class<T> type) {
Collection<? extends T> collection = toCollection(iterable);
T[] array = ObjectArrays.newArray(type, collection.size());
return collection.toArray(array);
}
/**
* 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 all instances of class {@code type} in {@code unfiltered}. The
* returned iterable has elements whose class is {@code type} or a subclass of
* {@code type}. The returned iterable's iterator does not support
* {@code remove()}.
*
* @param unfiltered an iterable containing objects of any type
* @param type the type of elements desired
* @return an unmodifiable iterable containing all elements of the original
* iterable that were of the requested type
*/
@GwtIncompatible("Class.isInstance")
public static <T> Iterable<T> filter(
final Iterable<?> unfiltered, final Class<T> type) {
checkNotNull(unfiltered);
checkNotNull(type);
return new IterableWithToString<T>() {
@Override
public Iterator<T> iterator() {
return Iterators.filter(unfiltered.iterator(), type);
}
};
}
/**
* 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) 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.annotations.GwtIncompatible;
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.IOException;
import java.io.ObjectInputStream;
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.NavigableSet;
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
@GwtIncompatible("not needed in emulated source")
private static final long serialVersionUID = 0;
@GwtIncompatible("java.io.ObjectInputStream")
private void readObject(ObjectInputStream stream)
throws IOException, ClassNotFoundException {
stream.defaultReadObject();
s = m.keySet();
}
}
/**
* 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();
}
}
/**
* Returns an unmodifiable view of the specified navigable set. This method
* allows modules to provide users with "read-only" access to internal
* navigable sets. Query operations on the returned set "read through" to the
* specified set, and attempts to modify the returned set, whether direct or
* via its collection views, result in an
* {@code UnsupportedOperationException}.
*
* <p>The returned navigable set will be serializable if the specified
* navigable set is serializable.
*
* @param set the navigable set for which an unmodifiable view is to be
* returned
* @return an unmodifiable view of the specified navigable set
* @since 12.0
*/
@GwtIncompatible("NavigableSet")
public static <E> NavigableSet<E> unmodifiableNavigableSet(
NavigableSet<E> set) {
if (set instanceof ImmutableSortedSet
|| set instanceof UnmodifiableNavigableSet) {
return set;
}
return new UnmodifiableNavigableSet<E>(set);
}
@GwtIncompatible("NavigableSet")
static final class UnmodifiableNavigableSet<E>
extends ForwardingSortedSet<E> implements NavigableSet<E>, Serializable {
private final NavigableSet<E> delegate;
UnmodifiableNavigableSet(NavigableSet<E> delegate) {
this.delegate = checkNotNull(delegate);
}
@Override
protected SortedSet<E> delegate() {
return Collections.unmodifiableSortedSet(delegate);
}
@Override
public E lower(E e) {
return delegate.lower(e);
}
@Override
public E floor(E e) {
return delegate.floor(e);
}
@Override
public E ceiling(E e) {
return delegate.ceiling(e);
}
@Override
public E higher(E e) {
return delegate.higher(e);
}
@Override
public E pollFirst() {
throw new UnsupportedOperationException();
}
@Override
public E pollLast() {
throw new UnsupportedOperationException();
}
private transient UnmodifiableNavigableSet<E> descendingSet;
@Override
public NavigableSet<E> descendingSet() {
UnmodifiableNavigableSet<E> result = descendingSet;
if (result == null) {
result = descendingSet = new UnmodifiableNavigableSet<E>(
delegate.descendingSet());
result.descendingSet = this;
}
return result;
}
@Override
public Iterator<E> descendingIterator() {
return Iterators.unmodifiableIterator(delegate.descendingIterator());
}
@Override
public NavigableSet<E> subSet(
E fromElement,
boolean fromInclusive,
E toElement,
boolean toInclusive) {
return unmodifiableNavigableSet(delegate.subSet(
fromElement,
fromInclusive,
toElement,
toInclusive));
}
@Override
public NavigableSet<E> headSet(E toElement, boolean inclusive) {
return unmodifiableNavigableSet(delegate.headSet(toElement, inclusive));
}
@Override
public NavigableSet<E> tailSet(E fromElement, boolean inclusive) {
return unmodifiableNavigableSet(
delegate.tailSet(fromElement, inclusive));
}
private static final long serialVersionUID = 0;
}
/**
* 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;
}
@GwtIncompatible("NavigableSet")
static class DescendingSet<E> extends ForwardingNavigableSet<E> {
private final NavigableSet<E> forward;
DescendingSet(NavigableSet<E> forward) {
this.forward = forward;
}
@Override
protected NavigableSet<E> delegate() {
return forward;
}
@Override
public E lower(E e) {
return forward.higher(e);
}
@Override
public E floor(E e) {
return forward.ceiling(e);
}
@Override
public E ceiling(E e) {
return forward.floor(e);
}
@Override
public E higher(E e) {
return forward.lower(e);
}
@Override
public E pollFirst() {
return forward.pollLast();
}
@Override
public E pollLast() {
return forward.pollFirst();
}
@Override
public NavigableSet<E> descendingSet() {
return forward;
}
@Override
public Iterator<E> descendingIterator() {
return forward.iterator();
}
@Override
public NavigableSet<E> subSet(
E fromElement,
boolean fromInclusive,
E toElement,
boolean toInclusive) {
return forward.subSet(toElement, toInclusive, fromElement, fromInclusive).descendingSet();
}
@Override
public NavigableSet<E> headSet(E toElement, boolean inclusive) {
return forward.tailSet(toElement, inclusive).descendingSet();
}
@Override
public NavigableSet<E> tailSet(E fromElement, boolean inclusive) {
return forward.headSet(fromElement, inclusive).descendingSet();
}
@SuppressWarnings("unchecked")
@Override
public Comparator<? super E> comparator() {
Comparator<? super E> forwardComparator = forward.comparator();
if (forwardComparator == null) {
return (Comparator) Ordering.natural().reverse();
} else {
return reverse(forwardComparator);
}
}
// If we inline this, we get a javac error.
private static <T> Ordering<T> reverse(Comparator<T> forward) {
return Ordering.from(forward).reverse();
}
@Override
public E first() {
return forward.last();
}
@Override
public SortedSet<E> headSet(E toElement) {
return standardHeadSet(toElement);
}
@Override
public E last() {
return forward.first();
}
@Override
public SortedSet<E> subSet(E fromElement, E toElement) {
return standardSubSet(fromElement, toElement);
}
@Override
public SortedSet<E> tailSet(E fromElement) {
return standardTailSet(fromElement);
}
@Override
public Iterator<E> iterator() {
return forward.descendingIterator();
}
@Override
public Object[] toArray() {
return standardToArray();
}
@Override
public <T> T[] toArray(T[] array) {
return standardToArray(array);
}
@Override
public String toString() {
return standardToString();
}
}
}
| 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.Beta;
import com.google.common.annotations.GwtCompatible;
import java.util.NoSuchElementException;
import java.util.Queue;
/**
* A queue which forwards all its method calls to another queue. Subclasses
* should override one or more methods to modify the behavior of the backing
* queue as desired per the <a
* href="http://en.wikipedia.org/wiki/Decorator_pattern">decorator pattern</a>.
*
* <p><b>Warning:</b> The methods of {@code ForwardingQueue} forward
* <b>indiscriminately</b> to the methods of the delegate. For example,
* overriding {@link #add} alone <b>will not</b> change the behavior of {@link
* #offer} which can lead to unexpected behavior. In this case, you should
* override {@code offer} as well, either providing your own implementation, or
* delegating to the provided {@code standardOffer} method.
*
* <p>The {@code standard} methods are not guaranteed to be thread-safe, even
* when all of the methods that they depend on are thread-safe.
*
* @author Mike Bostock
* @author Louis Wasserman
* @since 2.0 (imported from Google Collections Library)
*/
@GwtCompatible
public abstract class ForwardingQueue<E> extends ForwardingCollection<E>
implements Queue<E> {
/** Constructor for use by subclasses. */
protected ForwardingQueue() {}
@Override protected abstract Queue<E> delegate();
@Override
public boolean offer(E o) {
return delegate().offer(o);
}
@Override
public E poll() {
return delegate().poll();
}
@Override
public E remove() {
return delegate().remove();
}
@Override
public E peek() {
return delegate().peek();
}
@Override
public E element() {
return delegate().element();
}
/**
* A sensible definition of {@link #offer} in terms of {@link #add}. If you
* override {@link #add}, you may wish to override {@link #offer} to forward
* to this implementation.
*
* @since 7.0
*/
@Beta protected boolean standardOffer(E e) {
try {
return add(e);
} catch (IllegalStateException caught) {
return false;
}
}
/**
* A sensible definition of {@link #peek} in terms of {@link #element}. If you
* override {@link #element}, you may wish to override {@link #peek} to
* forward to this implementation.
*
* @since 7.0
*/
@Beta protected E standardPeek() {
try {
return element();
} catch (NoSuchElementException caught) {
return null;
}
}
/**
* A sensible definition of {@link #poll} in terms of {@link #remove}. If you
* override {@link #remove}, you may wish to override {@link #poll} to forward
* to this implementation.
*
* @since 7.0
*/
@Beta protected E standardPoll() {
try {
return remove();
} catch (NoSuchElementException caught) {
return null;
}
}
}
| 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.GwtCompatible;
import com.google.common.annotations.GwtIncompatible;
import java.lang.reflect.Array;
/**
* Methods factored out so that they can be emulated differently in GWT.
*
* @author Hayward Chan
*/
@GwtCompatible(emulated = true)
class Platform {
/**
* Clone the given array using {@link Object#clone()}. It is factored out so
* that it can be emulated in GWT.
*/
static <T> T[] clone(T[] array) {
return array.clone();
}
/**
* Wrapper around {@link System#arraycopy} so that it can be emulated
* correctly in GWT.
*
* <p>It is only intended for the case {@code src} and {@code dest} are
* different. It also doesn't validate the types and indices.
*
* <p>As of GWT 2.0, The built-in {@link System#arraycopy} doesn't work
* in general case. See
* http://code.google.com/p/google-web-toolkit/issues/detail?id=3621
* for more details.
*/
static void unsafeArrayCopy(
Object[] src, int srcPos, Object[] dest, int destPos, int length) {
System.arraycopy(src, srcPos, dest, destPos, length);
}
/**
* Returns a new array of the given length with the specified component type.
*
* @param type the component type
* @param length the length of the new array
*/
@GwtIncompatible("Array.newInstance(Class, int)")
@SuppressWarnings("unchecked")
static <T> T[] newArray(Class<T> type, int length) {
return (T[]) Array.newInstance(type, length);
}
/**
* 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
*/
static <T> T[] newArray(T[] reference, int length) {
Class<?> type = reference.getClass().getComponentType();
// the cast is safe because
// result.getClass() == reference.getClass().getComponentType()
@SuppressWarnings("unchecked")
T[] result = (T[]) Array.newInstance(type, length);
return result;
}
/**
* Configures the given map maker to use weak keys, if possible; does nothing
* otherwise (i.e., in GWT). This is sometimes acceptable, when only
* server-side code could generate enough volume that reclamation becomes
* important.
*/
static MapMaker tryWeakKeys(MapMaker mapMaker) {
return mapMaker.weakKeys();
}
private Platform() {}
}
| 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.collect.MapConstraints.ConstrainedMap;
import com.google.common.primitives.Primitives;
import java.util.HashMap;
import java.util.Map;
/**
* A mutable class-to-instance map backed by an arbitrary user-provided map.
* See also {@link ImmutableClassToInstanceMap}.
*
* <p>See the Guava User Guide article on <a href=
* "http://code.google.com/p/guava-libraries/wiki/NewCollectionTypesExplained#ClassToInstanceMap">
* {@code ClassToInstanceMap}</a>.
*
* @author Kevin Bourrillion
* @since 2.0 (imported from Google Collections Library)
*/
public final class MutableClassToInstanceMap<B>
extends ConstrainedMap<Class<? extends B>, B>
implements ClassToInstanceMap<B> {
/**
* Returns a new {@code MutableClassToInstanceMap} instance backed by a {@link
* HashMap} using the default initial capacity and load factor.
*/
public static <B> MutableClassToInstanceMap<B> create() {
return new MutableClassToInstanceMap<B>(
new HashMap<Class<? extends B>, B>());
}
/**
* Returns a new {@code MutableClassToInstanceMap} instance backed by a given
* empty {@code backingMap}. The caller surrenders control of the backing map,
* and thus should not allow any direct references to it to remain accessible.
*/
public static <B> MutableClassToInstanceMap<B> create(
Map<Class<? extends B>, B> backingMap) {
return new MutableClassToInstanceMap<B>(backingMap);
}
private MutableClassToInstanceMap(Map<Class<? extends B>, B> delegate) {
super(delegate, VALUE_CAN_BE_CAST_TO_KEY);
}
private static final MapConstraint<Class<?>, Object> VALUE_CAN_BE_CAST_TO_KEY
= new MapConstraint<Class<?>, Object>() {
@Override
public void checkKeyValue(Class<?> key, Object value) {
cast(key, value);
}
};
@Override
public <T extends B> T putInstance(Class<T> type, T value) {
return cast(type, put(type, value));
}
@Override
public <T extends B> T getInstance(Class<T> type) {
return cast(type, get(type));
}
private static <B, T extends B> T cast(Class<T> type, B value) {
return Primitives.wrap(type).cast(value);
}
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.collect;
import com.google.common.annotations.GwtCompatible;
import java.io.Serializable;
import javax.annotation.Nullable;
/**
* @see com.google.common.collect.Maps#immutableEntry(Object, Object)
*/
@GwtCompatible(serializable = true)
class ImmutableEntry<K, V> extends AbstractMapEntry<K, V>
implements Serializable {
private final K key;
private final V value;
ImmutableEntry(@Nullable K key, @Nullable V value) {
this.key = key;
this.value = value;
}
@Nullable @Override public K getKey() {
return key;
}
@Nullable @Override public V getValue() {
return value;
}
@Override public final V setValue(V value){
throw new UnsupportedOperationException();
}
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.collect;
import com.google.common.annotations.Beta;
import com.google.common.annotations.GwtCompatible;
import com.google.common.base.Objects;
import java.util.Map;
import java.util.Map.Entry;
import javax.annotation.Nullable;
/**
* A map entry which forwards all its method calls to another map entry.
* Subclasses should override one or more methods to modify the behavior of the
* backing map entry as desired per the <a
* href="http://en.wikipedia.org/wiki/Decorator_pattern">decorator pattern</a>.
*
* <p><i>Warning:</i> The methods of {@code ForwardingMapEntry} forward
* <i>indiscriminately</i> to the methods of the delegate. For example,
* overriding {@link #getValue} alone <i>will not</i> change the behavior of
* {@link #equals}, which can lead to unexpected behavior. In this case, you
* should override {@code equals} as well, either providing your own
* implementation, or delegating to the provided {@code standardEquals} method.
*
* <p>Each of the {@code standard} methods, where appropriate, use {@link
* Objects#equal} to test equality for both keys and values. This may not be
* the desired behavior for map implementations that use non-standard notions of
* key equality, such as the entry of a {@code SortedMap} whose comparator is
* not consistent with {@code equals}.
*
* <p>The {@code standard} methods are not guaranteed to be thread-safe, even
* when all of the methods that they depend on are thread-safe.
*
* @author Mike Bostock
* @author Louis Wasserman
* @since 2.0 (imported from Google Collections Library)
*/
@GwtCompatible
public abstract class ForwardingMapEntry<K, V>
extends ForwardingObject implements Map.Entry<K, V> {
// TODO(user): identify places where thread safety is actually lost
/** Constructor for use by subclasses. */
protected ForwardingMapEntry() {}
@Override protected abstract Map.Entry<K, V> delegate();
@Override
public K getKey() {
return delegate().getKey();
}
@Override
public V getValue() {
return delegate().getValue();
}
@Override
public V setValue(V value) {
return delegate().setValue(value);
}
@Override public boolean equals(@Nullable Object object) {
return delegate().equals(object);
}
@Override public int hashCode() {
return delegate().hashCode();
}
/**
* A sensible definition of {@link #equals(Object)} in terms of {@link
* #getKey()} and {@link #getValue()}. If you override either of these
* methods, you may wish to override {@link #equals(Object)} to forward to
* this implementation.
*
* @since 7.0
*/
@Beta protected boolean standardEquals(@Nullable Object object) {
if (object instanceof Entry) {
Entry<?, ?> that = (Entry<?, ?>) object;
return Objects.equal(this.getKey(), that.getKey())
&& Objects.equal(this.getValue(), that.getValue());
}
return false;
}
/**
* A sensible definition of {@link #hashCode()} in terms of {@link #getKey()}
* and {@link #getValue()}. If you override either of these methods, you may
* wish to override {@link #hashCode()} to forward to this implementation.
*
* @since 7.0
*/
@Beta protected int standardHashCode() {
K k = getKey();
V v = getValue();
return ((k == null) ? 0 : k.hashCode()) ^ ((v == null) ? 0 : v.hashCode());
}
/**
* A sensible definition of {@link #toString} in terms of {@link
* #getKey} and {@link #getValue}. If you override either of these
* methods, you may wish to override {@link #equals} to forward to this
* implementation.
*
* @since 7.0
*/
@Beta protected String standardToString() {
return getKey() + "=" + getValue();
}
}
| Java |
/*
* Copyright (C) 2012 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 java.util.Iterator;
import java.util.NavigableSet;
import java.util.SortedSet;
import javax.annotation.Nullable;
/**
* A navigable set which forwards all its method calls to another navigable set. Subclasses should
* override one or more methods to modify the behavior of the backing set as desired per the <a
* href="http://en.wikipedia.org/wiki/Decorator_pattern">decorator pattern</a>.
*
* <p><i>Warning:</i> The methods of {@code ForwardingNavigableSet} forward <i>indiscriminately</i>
* to the methods of the delegate. For example, overriding {@link #add} alone <i>will not</i>
* change the behavior of {@link #addAll}, which can lead to unexpected behavior. In this case, you
* should override {@code addAll} as well, either providing your own implementation, or delegating
* to the provided {@code standardAddAll} method.
*
* <p>Each of the {@code standard} methods uses the set's comparator (or the natural ordering of
* the elements, if there is no comparator) to test element equality. As a result, if the
* comparator is not consistent with equals, some of the standard implementations may violate the
* {@code Set} contract.
*
* <p>The {@code standard} methods and the collection views they return are not guaranteed to be
* thread-safe, even when all of the methods that they depend on are thread-safe.
*
* @author Louis Wasserman
* @since 12.0
*/
@Beta
public abstract class ForwardingNavigableSet<E>
extends ForwardingSortedSet<E> implements NavigableSet<E> {
/** Constructor for use by subclasses. */
protected ForwardingNavigableSet() {}
@Override
protected abstract NavigableSet<E> delegate();
@Override
public E lower(E e) {
return delegate().lower(e);
}
/**
* A sensible definition of {@link #lower} in terms of the {@code descendingIterator} method of
* {@link #headSet(Object, boolean)}. If you override {@link #headSet(Object, boolean)}, you may
* wish to override {@link #lower} to forward to this implementation.
*/
protected E standardLower(E e) {
return Iterators.getNext(headSet(e, false).descendingIterator(), null);
}
@Override
public E floor(E e) {
return delegate().floor(e);
}
/**
* A sensible definition of {@link #floor} in terms of the {@code descendingIterator} method of
* {@link #headSet(Object, boolean)}. If you override {@link #headSet(Object, boolean)}, you may
* wish to override {@link #floor} to forward to this implementation.
*/
protected E standardFloor(E e) {
return Iterators.getNext(headSet(e, true).descendingIterator(), null);
}
@Override
public E ceiling(E e) {
return delegate().ceiling(e);
}
/**
* A sensible definition of {@link #ceiling} in terms of the {@code iterator} method of
* {@link #tailSet(Object, boolean)}. If you override {@link #tailSet(Object, boolean)}, you may
* wish to override {@link #ceiling} to forward to this implementation.
*/
protected E standardCeiling(E e) {
return Iterators.getNext(tailSet(e, true).iterator(), null);
}
@Override
public E higher(E e) {
return delegate().higher(e);
}
/**
* A sensible definition of {@link #higher} in terms of the {@code iterator} method of
* {@link #tailSet(Object, boolean)}. If you override {@link #tailSet(Object, boolean)}, you may
* wish to override {@link #higher} to forward to this implementation.
*/
protected E standardHigher(E e) {
return Iterators.getNext(tailSet(e, false).iterator(), null);
}
@Override
public E pollFirst() {
return delegate().pollFirst();
}
/**
* A sensible definition of {@link #pollFirst} in terms of the {@code iterator} method. If you
* override {@link #iterator} you may wish to override {@link #pollFirst} to forward to this
* implementation.
*/
protected E standardPollFirst() {
return poll(iterator());
}
@Override
public E pollLast() {
return delegate().pollLast();
}
/**
* A sensible definition of {@link #pollLast} in terms of the {@code descendingIterator} method.
* If you override {@link #descendingIterator} you may wish to override {@link #pollLast} to
* forward to this implementation.
*/
protected E standardPollLast() {
return poll(delegate().descendingIterator());
}
protected E standardFirst() {
return iterator().next();
}
protected E standardLast() {
return descendingIterator().next();
}
@Override
public NavigableSet<E> descendingSet() {
return delegate().descendingSet();
}
/**
* A sensible implementation of {@link #descendingSet} in terms of the other methods of
* {@link NavigableSet}, notably including {@link NavigableSet#descendingIterator}.
*
* <p>In many cases, you may wish to override {@link #descendingSet} to forward to this
* implementation or a subclass thereof.
*
* @since 12.0
*/
@Beta
protected class StandardDescendingSet extends Sets.DescendingSet<E> {
/** Constructor for use by subclasses. */
public StandardDescendingSet() {
super(ForwardingNavigableSet.this);
}
}
@Override
public Iterator<E> descendingIterator() {
return delegate().descendingIterator();
}
@Override
public NavigableSet<E> subSet(
E fromElement,
boolean fromInclusive,
E toElement,
boolean toInclusive) {
return delegate().subSet(fromElement, fromInclusive, toElement, toInclusive);
}
/**
* A sensible definition of {@link #subSet(Object, boolean, Object, boolean)} in terms of the
* {@code headSet} and {@code tailSet} methods. In many cases, you may wish to override
* {@link #subSet(Object, boolean, Object, boolean)} to forward to this implementation.
*/
protected NavigableSet<E> standardSubSet(
E fromElement,
boolean fromInclusive,
E toElement,
boolean toInclusive) {
return tailSet(fromElement, fromInclusive).headSet(toElement, toInclusive);
}
/**
* A sensible definition of {@link #subSet(Object, Object)} in terms of the
* {@link #subSet(Object, boolean, Object, boolean)} method. If you override
* {@link #subSet(Object, boolean, Object, boolean)}, you may wish to override
* {@link #subSet(Object, Object)} to forward to this implementation.
*/
@Override
protected SortedSet<E> standardSubSet(E fromElement, E toElement) {
return subSet(fromElement, true, toElement, false);
}
@Override
public NavigableSet<E> headSet(E toElement, boolean inclusive) {
return delegate().headSet(toElement, inclusive);
}
/**
* A sensible definition of {@link #headSet(Object)} in terms of the
* {@link #headSet(Object, boolean)} method. If you override
* {@link #headSet(Object, boolean)}, you may wish to override
* {@link #headSet(Object)} to forward to this implementation.
*/
protected SortedSet<E> standardHeadSet(E toElement) {
return headSet(toElement, false);
}
@Override
public NavigableSet<E> tailSet(E fromElement, boolean inclusive) {
return delegate().tailSet(fromElement, inclusive);
}
/**
* A sensible definition of {@link #tailSet(Object)} in terms of the
* {@link #tailSet(Object, boolean)} method. If you override
* {@link #tailSet(Object, boolean)}, you may wish to override
* {@link #tailSet(Object)} to forward to this implementation.
*/
protected SortedSet<E> standardTailSet(E fromElement) {
return tailSet(fromElement, true);
}
@Nullable
private E poll(Iterator<E> iterator) {
if (iterator.hasNext()) {
E result = iterator.next();
iterator.remove();
return result;
}
return null;
}
}
| 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.io.Serializable;
import java.util.Iterator;
import javax.annotation.Nullable;
/**
* An ordering which sorts iterables by comparing corresponding elements
* pairwise.
*/
@GwtCompatible(serializable = true)
final class LexicographicalOrdering<T>
extends Ordering<Iterable<T>> implements Serializable {
final Ordering<? super T> elementOrder;
LexicographicalOrdering(Ordering<? super T> elementOrder) {
this.elementOrder = elementOrder;
}
@Override public int compare(
Iterable<T> leftIterable, Iterable<T> rightIterable) {
Iterator<T> left = leftIterable.iterator();
Iterator<T> right = rightIterable.iterator();
while (left.hasNext()) {
if (!right.hasNext()) {
return LEFT_IS_GREATER; // because it's longer
}
int result = elementOrder.compare(left.next(), right.next());
if (result != 0) {
return result;
}
}
if (right.hasNext()) {
return RIGHT_IS_GREATER; // because it's longer
}
return 0;
}
@Override public boolean equals(@Nullable Object object) {
if (object == this) {
return true;
}
if (object instanceof LexicographicalOrdering) {
LexicographicalOrdering<?> that = (LexicographicalOrdering<?>) object;
return this.elementOrder.equals(that.elementOrder);
}
return false;
}
@Override public int hashCode() {
return elementOrder.hashCode() ^ 2075626741; // meaningless
}
@Override public String toString() {
return elementOrder + ".lexicographical()";
}
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.collect;
import com.google.common.annotations.Beta;
import com.google.common.annotations.GwtCompatible;
import java.util.Comparator;
import java.util.Iterator;
import java.util.NoSuchElementException;
import java.util.SortedMap;
import javax.annotation.Nullable;
/**
* A sorted map which forwards all its method calls to another sorted map.
* Subclasses should override one or more methods to modify the behavior of
* the backing sorted map as desired per the <a
* href="http://en.wikipedia.org/wiki/Decorator_pattern">decorator pattern</a>.
*
* <p><i>Warning:</i> The methods of {@code ForwardingSortedMap} forward
* <i>indiscriminately</i> to the methods of the delegate. For example,
* overriding {@link #put} alone <i>will not</i> change the behavior of {@link
* #putAll}, which can lead to unexpected behavior. In this case, you should
* override {@code putAll} as well, either providing your own implementation, or
* delegating to the provided {@code standardPutAll} method.
*
* <p>Each of the {@code standard} methods, where appropriate, use the
* comparator of the map to test equality for both keys and values, unlike
* {@code ForwardingMap}.
*
* <p>The {@code standard} methods and the collection views they return are not
* guaranteed to be thread-safe, even when all of the methods that they depend
* on are thread-safe.
*
* @author Mike Bostock
* @author Louis Wasserman
* @since 2.0 (imported from Google Collections Library)
*/
@GwtCompatible
public abstract class ForwardingSortedMap<K, V> extends ForwardingMap<K, V>
implements SortedMap<K, V> {
// TODO(user): identify places where thread safety is actually lost
/** Constructor for use by subclasses. */
protected ForwardingSortedMap() {}
@Override protected abstract SortedMap<K, V> delegate();
@Override
public Comparator<? super K> comparator() {
return delegate().comparator();
}
@Override
public K firstKey() {
return delegate().firstKey();
}
@Override
public SortedMap<K, V> headMap(K toKey) {
return delegate().headMap(toKey);
}
@Override
public K lastKey() {
return delegate().lastKey();
}
@Override
public SortedMap<K, V> subMap(K fromKey, K toKey) {
return delegate().subMap(fromKey, toKey);
}
@Override
public SortedMap<K, V> tailMap(K fromKey) {
return delegate().tailMap(fromKey);
}
// unsafe, but worst case is a CCE is thrown, which callers will be expecting
@SuppressWarnings("unchecked")
private int unsafeCompare(Object k1, Object k2) {
Comparator<? super K> comparator = comparator();
if (comparator == null) {
return ((Comparable<Object>) k1).compareTo(k2);
} else {
return ((Comparator<Object>) comparator).compare(k1, k2);
}
}
/**
* A sensible definition of {@link #containsKey} in terms of the {@code
* firstKey()} method of {@link #tailMap}. If you override {@link #tailMap},
* you may wish to override {@link #containsKey} to forward to this
* implementation.
*
* @since 7.0
*/
@Override @Beta protected boolean standardContainsKey(@Nullable Object key) {
try {
// any CCE will be caught
@SuppressWarnings("unchecked")
SortedMap<Object, V> self = (SortedMap<Object, V>) this;
Object ceilingKey = self.tailMap(key).firstKey();
return unsafeCompare(ceilingKey, key) == 0;
} catch (ClassCastException e) {
return false;
} catch (NoSuchElementException e) {
return false;
} catch (NullPointerException e) {
return false;
}
}
/**
* A sensible definition of {@link #remove} in terms of the {@code
* iterator()} of the {@code entrySet()} of {@link #tailMap}. If you override
* {@link #tailMap}, you may wish to override {@link #remove} to forward
* to this implementation.
*
* @since 7.0
*/
@Override @Beta protected V standardRemove(@Nullable Object key) {
try {
// any CCE will be caught
@SuppressWarnings("unchecked")
SortedMap<Object, V> self = (SortedMap<Object, V>) this;
Iterator<Entry<Object, V>> entryIterator =
self.tailMap(key).entrySet().iterator();
if (entryIterator.hasNext()) {
Entry<Object, V> ceilingEntry = entryIterator.next();
if (unsafeCompare(ceilingEntry.getKey(), key) == 0) {
V value = ceilingEntry.getValue();
entryIterator.remove();
return value;
}
}
} catch (ClassCastException e) {
return null;
} catch (NullPointerException e) {
return null;
}
return null;
}
/**
* A sensible default implementation of {@link #subMap(Object, Object)} in
* terms of {@link #headMap(Object)} and {@link #tailMap(Object)}. In some
* situations, you may wish to override {@link #subMap(Object, Object)} to
* forward to this implementation.
*
* @since 7.0
*/
@Beta protected SortedMap<K, V> standardSubMap(K fromKey, K toKey) {
return tailMap(fromKey).headMap(toKey);
}
}
| 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.Map;
import java.util.Set;
import javax.annotation.Nullable;
/**
* A bimap (or "bidirectional map") is a map that preserves the uniqueness of
* its values as well as that of its keys. This constraint enables bimaps to
* support an "inverse view", which is another bimap containing the same entries
* as this bimap but with reversed keys and values.
*
* <p>See the Guava User Guide article on <a href=
* "http://code.google.com/p/guava-libraries/wiki/NewCollectionTypesExplained#BiMap">
* {@code BiMap}</a>.
*
* @author Kevin Bourrillion
* @since 2.0 (imported from Google Collections Library)
*/
@GwtCompatible
public interface BiMap<K, V> extends Map<K, V> {
// Modification Operations
/**
* {@inheritDoc}
*
* @throws IllegalArgumentException if the given value is already bound to a
* different key in this bimap. The bimap will remain unmodified in this
* event. To avoid this exception, call {@link #forcePut} instead.
*/
@Override
V put(@Nullable K key, @Nullable V value);
/**
* An alternate form of {@code put} that silently removes any existing entry
* with the value {@code value} before proceeding with the {@link #put}
* operation. If the bimap previously contained the provided key-value
* mapping, this method has no effect.
*
* <p>Note that a successful call to this method could cause the size of the
* bimap to increase by one, stay the same, or even decrease by one.
*
* <p><b>Warning:</b> If an existing entry with this value is removed, the key
* for that entry is discarded and not returned.
*
* @param key the key with which the specified value is to be associated
* @param value the value to be associated with the specified key
* @return the value which was previously associated with the key, which may
* be {@code null}, or {@code null} if there was no previous entry
*/
V forcePut(@Nullable K key, @Nullable V value);
// Bulk Operations
/**
* {@inheritDoc}
*
* <p><b>Warning:</b> the results of calling this method may vary depending on
* the iteration order of {@code map}.
*
* @throws IllegalArgumentException if an attempt to {@code put} any
* entry fails. Note that some map entries may have been added to the
* bimap before the exception was thrown.
*/
@Override
void putAll(Map<? extends K, ? extends V> map);
// Views
/**
* {@inheritDoc}
*
* <p>Because a bimap has unique values, this method returns a {@link Set},
* instead of the {@link java.util.Collection} specified in the {@link Map}
* interface.
*/
@Override
Set<V> values();
/**
* Returns the inverse view of this bimap, which maps each of this bimap's
* values to its associated key. The two bimaps are backed by the same data;
* any changes to one will appear in the other.
*
* <p><b>Note:</b>There is no guaranteed correspondence between the iteration
* order of a bimap and that of its inverse.
*
* @return the inverse view of this bimap
*/
BiMap<V, K> inverse();
}
| 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.GwtIncompatible;
import java.io.IOException;
import java.io.ObjectInputStream;
import java.io.ObjectOutputStream;
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();
}
/**
* @serialData key comparator, value comparator, number of distinct keys, and
* then for each distinct key: the key, number of values for that key, and
* key values
*/
@GwtIncompatible("java.io.ObjectOutputStream")
private void writeObject(ObjectOutputStream stream) throws IOException {
stream.defaultWriteObject();
stream.writeObject(keyComparator());
stream.writeObject(valueComparator());
Serialization.writeMultimap(this, stream);
}
@GwtIncompatible("java.io.ObjectInputStream")
@SuppressWarnings("unchecked") // reading data stored by writeObject
private void readObject(ObjectInputStream stream)
throws IOException, ClassNotFoundException {
stream.defaultReadObject();
keyComparator = checkNotNull((Comparator<? super K>) stream.readObject());
valueComparator = checkNotNull((Comparator<? super V>) stream.readObject());
setMap(new TreeMap<K, Collection<V>>(keyComparator));
Serialization.populateMultimap(this, stream);
}
@GwtIncompatible("not needed in emulated source")
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.collect;
import com.google.common.annotations.Beta;
import com.google.common.annotations.GwtCompatible;
import javax.annotation.Nullable;
/**
* A constraint on the keys and values that may be added to a {@code Map} or
* {@code Multimap}. For example, {@link MapConstraints#notNull()}, which
* prevents a map from including any null keys or values, could be implemented
* like this: <pre> {@code
*
* public void checkKeyValue(Object key, Object value) {
* if (key == null || value == null) {
* throw new NullPointerException();
* }
* }}</pre>
*
* In order to be effective, constraints should be deterministic; that is, they
* should not depend on state that can change (such as external state, random
* variables, and time) and should only depend on the value of the passed-in key
* and value. A non-deterministic constraint cannot reliably enforce that all
* the collection's elements meet the constraint, since the constraint is only
* enforced when elements are added.
*
* @author Mike Bostock
* @see MapConstraints
* @see Constraint
* @since 3.0
*/
@GwtCompatible
@Beta
public interface MapConstraint<K, V> {
/**
* Throws a suitable {@code RuntimeException} if the specified key or value is
* illegal. Typically this is either a {@link NullPointerException}, an
* {@link IllegalArgumentException}, or a {@link ClassCastException}, though
* an application-specific exception class may be used if appropriate.
*/
void checkKeyValue(@Nullable K key, @Nullable V value);
/**
* Returns a brief human readable description of this constraint, such as
* "Not null".
*/
@Override
String 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.
*/
/**
* This package contains generic collection interfaces and implementations, and
* other utilities for working with collections. It is a part of the open-source
* <a href="http://guava-libraries.googlecode.com">Guava libraries</a>.
*
* <h2>Collection Types</h2>
*
* <dl>
* <dt>{@link com.google.common.collect.BiMap}
* <dd>An extension of {@link java.util.Map} that guarantees the uniqueness of
* its values as well as that of its keys. This is sometimes called an
* "invertible map," since the restriction on values enables it to support
* an {@linkplain com.google.common.collect.BiMap#inverse inverse view} --
* which is another instance of {@code BiMap}.
*
* <dt>{@link com.google.common.collect.Multiset}
* <dd>An extension of {@link java.util.Collection} that may contain duplicate
* values like a {@link java.util.List}, yet has order-independent equality
* like a {@link java.util.Set}. One typical use for a multiset is to
* represent a histogram.
*
* <dt>{@link com.google.common.collect.Multimap}
* <dd>A new type, which is similar to {@link java.util.Map}, but may contain
* multiple entries with the same key. Some behaviors of
* {@link com.google.common.collect.Multimap} are left unspecified and are
* provided only by the subtypes mentioned below.
*
* <dt>{@link com.google.common.collect.ListMultimap}
* <dd>An extension of {@link com.google.common.collect.Multimap} which permits
* duplicate entries, supports random access of values for a particular key,
* and has <i>partially order-dependent equality</i> as defined by
* {@link com.google.common.collect.ListMultimap#equals(Object)}. {@code
* ListMultimap} takes its name from the fact that the {@linkplain
* com.google.common.collect.ListMultimap#get collection of values}
* associated with a given key fulfills the {@link java.util.List} contract.
*
* <dt>{@link com.google.common.collect.SetMultimap}
* <dd>An extension of {@link com.google.common.collect.Multimap} which has
* order-independent equality and does not allow duplicate entries; that is,
* while a key may appear twice in a {@code SetMultimap}, each must map to a
* different value. {@code SetMultimap} takes its name from the fact that
* the {@linkplain com.google.common.collect.SetMultimap#get collection of
* values} associated with a given key fulfills the {@link java.util.Set}
* contract.
*
* <dt>{@link com.google.common.collect.SortedSetMultimap}
* <dd>An extension of {@link com.google.common.collect.SetMultimap} for which
* the {@linkplain com.google.common.collect.SortedSetMultimap#get
* collection values} associated with a given key is a
* {@link java.util.SortedSet}.
*
* <dt>{@link com.google.common.collect.Table}
* <dd>A new type, which is similar to {@link java.util.Map}, but which indexes
* its values by an ordered pair of keys, a row key and column key.
*
* <dt>{@link com.google.common.collect.ClassToInstanceMap}
* <dd>An extension of {@link java.util.Map} that associates a raw type with an
* instance of that type.
* </dl>
*
* <h2>Collection Implementations</h2>
*
* <h3>of {@link java.util.List}</h3>
* <ul>
* <li>{@link com.google.common.collect.ImmutableList}
* </ul>
*
* <h3>of {@link java.util.Set}</h3>
* <ul>
* <li>{@link com.google.common.collect.ImmutableSet}
* <li>{@link com.google.common.collect.ImmutableSortedSet}
* <li>{@link com.google.common.collect.ContiguousSet} (see {@code Ranges})
* </ul>
*
* <h3>of {@link java.util.Map}</h3>
* <ul>
* <li>{@link com.google.common.collect.ImmutableMap}
* <li>{@link com.google.common.collect.ImmutableSortedMap}
* <li>{@link com.google.common.collect.MapMaker}
* </ul>
*
* <h3>of {@link com.google.common.collect.BiMap}</h3>
* <ul>
* <li>{@link com.google.common.collect.ImmutableBiMap}
* <li>{@link com.google.common.collect.HashBiMap}
* <li>{@link com.google.common.collect.EnumBiMap}
* <li>{@link com.google.common.collect.EnumHashBiMap}
* </ul>
*
* <h3>of {@link com.google.common.collect.Multiset}</h3>
* <ul>
* <li>{@link com.google.common.collect.ImmutableMultiset}
* <li>{@link com.google.common.collect.HashMultiset}
* <li>{@link com.google.common.collect.LinkedHashMultiset}
* <li>{@link com.google.common.collect.TreeMultiset}
* <li>{@link com.google.common.collect.EnumMultiset}
* <li>{@link com.google.common.collect.ConcurrentHashMultiset}
* </ul>
*
* <h3>of {@link com.google.common.collect.Multimap}</h3>
* <ul>
* <li>{@link com.google.common.collect.ImmutableMultimap}
* <li>{@link com.google.common.collect.ImmutableListMultimap}
* <li>{@link com.google.common.collect.ImmutableSetMultimap}
* <li>{@link com.google.common.collect.ArrayListMultimap}
* <li>{@link com.google.common.collect.HashMultimap}
* <li>{@link com.google.common.collect.TreeMultimap}
* <li>{@link com.google.common.collect.LinkedHashMultimap}
* <li>{@link com.google.common.collect.LinkedListMultimap}
* </ul>
*
* <h3>of {@link com.google.common.collect.Table}</h3>
* <ul>
* <li>{@link com.google.common.collect.ImmutableTable}
* <li>{@link com.google.common.collect.ArrayTable}
* <li>{@link com.google.common.collect.HashBasedTable}
* <li>{@link com.google.common.collect.TreeBasedTable}
* </ul>
*
* <h3>of {@link com.google.common.collect.ClassToInstanceMap}</h3>
* <ul>
* <li>{@link com.google.common.collect.ImmutableClassToInstanceMap}
* <li>{@link com.google.common.collect.MutableClassToInstanceMap}
* </ul>
*
* <h2>Classes of static utility methods</h2>
*
* <ul>
* <li>{@link com.google.common.collect.Collections2}
* <li>{@link com.google.common.collect.Iterators}
* <li>{@link com.google.common.collect.Iterables}
* <li>{@link com.google.common.collect.Lists}
* <li>{@link com.google.common.collect.Maps}
* <li>{@link com.google.common.collect.Sets}
* <li>{@link com.google.common.collect.Multisets}
* <li>{@link com.google.common.collect.Multimaps}
* <li>{@link com.google.common.collect.SortedMaps}
* <li>{@link com.google.common.collect.Tables}
* <li>{@link com.google.common.collect.ObjectArrays}
* </ul>
*
* <h2>Comparison</h2>
*
* <ul>
* <li>{@link com.google.common.collect.Ordering}
* <li>{@link com.google.common.collect.ComparisonChain}
* </ul>
*
* <h2>Abstract implementations</h2>
*
* <ul>
* <li>{@link com.google.common.collect.AbstractIterator}
* <li>{@link com.google.common.collect.AbstractSequentialIterator}
* <li>{@link com.google.common.collect.ImmutableCollection}
* <li>{@link com.google.common.collect.UnmodifiableIterator}
* <li>{@link com.google.common.collect.UnmodifiableListIterator}
* </ul>
*
* <h2>Ranges</h2>
*
* <ul>
* <li>{@link com.google.common.collect.Range}
* <li>{@link com.google.common.collect.Ranges}
* <li>{@link com.google.common.collect.DiscreteDomain}
* <li>{@link com.google.common.collect.DiscreteDomains}
* <li>{@link com.google.common.collect.ContiguousSet}
* </ul>
*
* <h2>Other</h2>
*
* <ul>
* <li>{@link com.google.common.collect.Interner},
* {@link com.google.common.collect.Interners}
* <li>{@link com.google.common.collect.Constraint},
* {@link com.google.common.collect.Constraints}
* <li>{@link com.google.common.collect.MapConstraint},
* {@link com.google.common.collect.MapConstraints}
* <li>{@link com.google.common.collect.MapDifference},
* {@link com.google.common.collect.SortedMapDifference}
* <li>{@link com.google.common.collect.MinMaxPriorityQueue}
* <li>{@link com.google.common.collect.PeekingIterator}
* </ul>
*
* <h2>Forwarding collections</h2>
*
* <ul>
* <li>{@link com.google.common.collect.ForwardingCollection}
* <li>{@link com.google.common.collect.ForwardingConcurrentMap}
* <li>{@link com.google.common.collect.ForwardingIterator}
* <li>{@link com.google.common.collect.ForwardingList}
* <li>{@link com.google.common.collect.ForwardingListIterator}
* <li>{@link com.google.common.collect.ForwardingListMultimap}
* <li>{@link com.google.common.collect.ForwardingMap}
* <li>{@link com.google.common.collect.ForwardingMapEntry}
* <li>{@link com.google.common.collect.ForwardingMultimap}
* <li>{@link com.google.common.collect.ForwardingMultiset}
* <li>{@link com.google.common.collect.ForwardingObject}
* <li>{@link com.google.common.collect.ForwardingQueue}
* <li>{@link com.google.common.collect.ForwardingSet}
* <li>{@link com.google.common.collect.ForwardingSetMultimap}
* <li>{@link com.google.common.collect.ForwardingSortedMap}
* <li>{@link com.google.common.collect.ForwardingSortedMultiset}
* <li>{@link com.google.common.collect.ForwardingSortedSet}
* <li>{@link com.google.common.collect.ForwardingSortedSetMultimap}
* <li>{@link com.google.common.collect.ForwardingTable}
* </ul>
*/
@javax.annotation.ParametersAreNonnullByDefault
package com.google.common.collect;
| 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.annotations.GwtIncompatible;
import com.google.common.base.Objects;
import com.google.common.base.Preconditions;
import java.io.IOException;
import java.io.ObjectInputStream;
import java.io.ObjectOutputStream;
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();
}
/**
* @serialData the number of distinct keys, and then for each distinct key:
* the first key, the number of values for that key, and the key's values,
* followed by successive keys and values from the entries() ordering
*/
@GwtIncompatible("java.io.ObjectOutputStream")
private void writeObject(ObjectOutputStream stream) throws IOException {
stream.defaultWriteObject();
stream.writeInt(size());
for (Entry<K, V> entry : entries()) {
stream.writeObject(entry.getKey());
stream.writeObject(entry.getValue());
}
}
@GwtIncompatible("java.io.ObjectInputStream")
private void readObject(ObjectInputStream stream)
throws IOException, ClassNotFoundException {
stream.defaultReadObject();
keyCount = LinkedHashMultiset.create();
keyToKeyHead = Maps.newHashMap();
keyToKeyTail = Maps.newHashMap();
int size = stream.readInt();
for (int i = 0; i < size; i++) {
@SuppressWarnings("unchecked") // reading data stored by writeObject
K key = (K) stream.readObject();
@SuppressWarnings("unchecked") // reading data stored by writeObject
V value = (V) stream.readObject();
put(key, value);
}
}
@GwtIncompatible("java serialization not supported")
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.collect;
import static com.google.common.base.Preconditions.checkNotNull;
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.Collections;
import java.util.Comparator;
import java.util.Iterator;
import java.util.List;
/**
* An immutable {@code SortedMultiset} that stores its elements in a sorted array. Some instances
* are ordered by an explicit comparator, while others follow the natural sort ordering of their
* elements. Either way, null elements are not supported.
*
* <p>Unlike {@link Multisets#unmodifiableSortedMultiset}, which is a <i>view</i> of a separate
* collection that can still change, an instance of {@code ImmutableSortedMultiset} contains its
* own private data and will <i>never</i> change. This class is convenient for {@code public static
* final} multisets ("constant multisets") and also lets you easily make a "defensive copy" of a
* set provided to your class by a caller.
*
* <p>The multisets returned by the {@link #headMultiset}, {@link #tailMultiset}, and
* {@link #subMultiset} methods share the same array as the original multiset, preventing that
* array from being garbage collected. If this is a concern, the data may be copied into a
* correctly-sized array by calling {@link #copyOfSorted}.
*
* <p><b>Note on element equivalence:</b> The {@link #contains(Object)},
* {@link #containsAll(Collection)}, and {@link #equals(Object)} implementations must check whether
* a provided object is equivalent to an element in the collection. Unlike most collections, an
* {@code ImmutableSortedMultiset} doesn't use {@link Object#equals} to determine if two elements
* are equivalent. Instead, with an explicit comparator, the following relation determines whether
* elements {@code x} and {@code y} are equivalent:
*
* <pre> {@code
*
* {(x, y) | comparator.compare(x, y) == 0}}</pre>
*
* With natural ordering of elements, the following relation determines whether two elements are
* equivalent:
*
* <pre> {@code
*
* {(x, y) | x.compareTo(y) == 0}}</pre>
*
* <b>Warning:</b> Like most multisets, an {@code ImmutableSortedMultiset} will not function
* correctly if an element is modified after being placed in the multiset. For this reason, and to
* avoid general confusion, it is strongly recommended to place only immutable objects into this
* collection.
*
* <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 type 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 Louis Wasserman
*/
@GwtIncompatible("hasn't been tested yet")
abstract class ImmutableSortedMultiset<E> extends ImmutableSortedMultisetFauxverideShim<E>
implements SortedMultiset<E> {
// TODO(user): GWT compatibility
private static final Comparator<Comparable> NATURAL_ORDER = Ordering.natural();
private static final ImmutableSortedMultiset<Comparable> NATURAL_EMPTY_MULTISET =
new EmptyImmutableSortedMultiset<Comparable>(NATURAL_ORDER);
/**
* Returns the empty immutable sorted multiset.
*/
@SuppressWarnings("unchecked")
public static <E> ImmutableSortedMultiset<E> of() {
return (ImmutableSortedMultiset) NATURAL_EMPTY_MULTISET;
}
/**
* Returns an immutable sorted multiset containing a single element.
*/
public static <E extends Comparable<? super E>> ImmutableSortedMultiset<E> of(E element) {
return RegularImmutableSortedMultiset.createFromSorted(
NATURAL_ORDER, ImmutableList.of(Multisets.immutableEntry(checkNotNull(element), 1)));
}
/**
* Returns an immutable sorted multiset containing the given elements sorted by their natural
* ordering.
*
* @throws NullPointerException if any element is null
*/
@SuppressWarnings("unchecked")
public static <E extends Comparable<? super E>> ImmutableSortedMultiset<E> of(E e1, E e2) {
return copyOf(Ordering.natural(), Arrays.asList(e1, e2));
}
/**
* Returns an immutable sorted multiset containing the given elements sorted by their natural
* ordering.
*
* @throws NullPointerException if any element is null
*/
@SuppressWarnings("unchecked")
public static <E extends Comparable<? super E>> ImmutableSortedMultiset<E> of(E e1, E e2, E e3) {
return copyOf(Ordering.natural(), Arrays.asList(e1, e2, e3));
}
/**
* Returns an immutable sorted multiset containing the given elements sorted by their natural
* ordering.
*
* @throws NullPointerException if any element is null
*/
@SuppressWarnings("unchecked")
public static <E extends Comparable<? super E>> ImmutableSortedMultiset<E> of(
E e1, E e2, E e3, E e4) {
return copyOf(Ordering.natural(), Arrays.asList(e1, e2, e3, e4));
}
/**
* Returns an immutable sorted multiset containing the given elements sorted by their natural
* ordering.
*
* @throws NullPointerException if any element is null
*/
@SuppressWarnings("unchecked")
public static <E extends Comparable<? super E>> ImmutableSortedMultiset<E> of(
E e1, E e2, E e3, E e4, E e5) {
return copyOf(Ordering.natural(), Arrays.asList(e1, e2, e3, e4, e5));
}
/**
* Returns an immutable sorted multiset containing the given elements sorted by their natural
* ordering.
*
* @throws NullPointerException if any element is null
*/
@SuppressWarnings("unchecked")
public static <E extends Comparable<? super E>> ImmutableSortedMultiset<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);
return copyOf(Ordering.natural(), all);
}
/**
* Returns an immutable sorted multiset containing the given elements sorted by their natural
* ordering.
*
* @throws NullPointerException if any of {@code elements} is null
*/
public static <E extends Comparable<? super E>> ImmutableSortedMultiset<E> copyOf(E[] elements) {
return copyOf(Ordering.natural(), Arrays.asList(elements));
}
/**
* Returns an immutable sorted multiset containing the given elements sorted by their natural
* ordering. To create a copy of a {@code SortedMultiset} that preserves the
* comparator, call {@link #copyOfSorted} instead. This method iterates over {@code elements} at
* most once.
*
* <p>Note that if {@code s} is a {@code multiset<String>}, then {@code
* ImmutableSortedMultiset.copyOf(s)} returns an {@code ImmutableSortedMultiset<String>}
* containing each of the strings in {@code s}, while {@code ImmutableSortedMultiset.of(s)}
* returns an {@code ImmutableSortedMultiset<multiset<String>>} containing one element (the given
* multiset itself).
*
* <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.
*
* <p>This method is not type-safe, as it may be called on elements that are not mutually
* comparable.
*
* @throws ClassCastException if the elements are not mutually comparable
* @throws NullPointerException if any of {@code elements} is null
*/
public static <E> ImmutableSortedMultiset<E> copyOf(Iterable<? extends E> elements) {
// Hack around E not being a subtype of Comparable.
// Unsafe, see ImmutableSortedMultisetFauxverideShim.
@SuppressWarnings("unchecked")
Ordering<E> naturalOrder = (Ordering<E>) Ordering.<Comparable>natural();
return copyOf(naturalOrder, elements);
}
/**
* Returns an immutable sorted multiset containing the given elements sorted by their natural
* ordering.
*
* <p>This method is not type-safe, as it may be called on elements that are not mutually
* comparable.
*
* @throws ClassCastException if the elements are not mutually comparable
* @throws NullPointerException if any of {@code elements} is null
*/
public static <E> ImmutableSortedMultiset<E> copyOf(Iterator<? extends E> elements) {
// Hack around E not being a subtype of Comparable.
// Unsafe, see ImmutableSortedMultisetFauxverideShim.
@SuppressWarnings("unchecked")
Ordering<E> naturalOrder = (Ordering<E>) Ordering.<Comparable>natural();
return copyOfInternal(naturalOrder, elements);
}
/**
* Returns an immutable sorted multiset containing the given elements sorted by the given {@code
* Comparator}.
*
* @throws NullPointerException if {@code comparator} or any of {@code elements} is null
*/
public static <E> ImmutableSortedMultiset<E> copyOf(
Comparator<? super E> comparator, Iterator<? extends E> elements) {
checkNotNull(comparator);
return copyOfInternal(comparator, elements);
}
/**
* Returns an immutable sorted multiset containing the given elements sorted by the given {@code
* Comparator}. This method iterates over {@code elements} at most once.
*
* <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 {@code comparator} or any of {@code elements} is null
*/
public static <E> ImmutableSortedMultiset<E> copyOf(
Comparator<? super E> comparator, Iterable<? extends E> elements) {
checkNotNull(comparator);
return copyOfInternal(comparator, elements);
}
/**
* Returns an immutable sorted multiset containing the elements of a sorted multiset, sorted by
* the same {@code Comparator}. That behavior differs from {@link #copyOf(Iterable)}, which
* always uses the natural ordering of the elements.
*
* <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.
*
* <p>This method is safe to use even when {@code sortedMultiset} is a synchronized or concurrent
* collection that is currently being modified by another thread.
*
* @throws NullPointerException if {@code sortedMultiset} or any of its elements is null
*/
@SuppressWarnings("unchecked")
public static <E> ImmutableSortedMultiset<E> copyOfSorted(SortedMultiset<E> sortedMultiset) {
Comparator<? super E> comparator = sortedMultiset.comparator();
if (comparator == null) {
comparator = (Comparator<? super E>) NATURAL_ORDER;
}
return copyOfInternal(comparator, sortedMultiset);
}
@SuppressWarnings("unchecked")
private static <E> ImmutableSortedMultiset<E> copyOfInternal(
Comparator<? super E> comparator, Iterable<? extends E> iterable) {
if (SortedIterables.hasSameComparator(comparator, iterable)
&& iterable instanceof ImmutableSortedMultiset<?>) {
ImmutableSortedMultiset<E> multiset = (ImmutableSortedMultiset<E>) iterable;
if (!multiset.isPartialView()) {
return (ImmutableSortedMultiset<E>) iterable;
}
}
ImmutableList<Entry<E>> entries =
(ImmutableList) ImmutableList.copyOf(SortedIterables.sortedCounts(comparator, iterable));
if (entries.isEmpty()) {
return emptyMultiset(comparator);
}
verifyEntries(entries);
return RegularImmutableSortedMultiset.createFromSorted(comparator, entries);
}
private static <E> ImmutableSortedMultiset<E> copyOfInternal(
Comparator<? super E> comparator, Iterator<? extends E> iterator) {
@SuppressWarnings("unchecked") // We can safely cast from IL<Entry<? extends E>> to IL<Entry<E>>
ImmutableList<Entry<E>> entries =
(ImmutableList) ImmutableList.copyOf(SortedIterables.sortedCounts(comparator, iterator));
if (entries.isEmpty()) {
return emptyMultiset(comparator);
}
verifyEntries(entries);
return RegularImmutableSortedMultiset.createFromSorted(comparator, entries);
}
private static <E> void verifyEntries(Collection<Entry<E>> entries) {
for (Entry<E> entry : entries) {
checkNotNull(entry.getElement());
}
}
@SuppressWarnings("unchecked")
static <E> ImmutableSortedMultiset<E> emptyMultiset(Comparator<? super E> comparator) {
if (NATURAL_ORDER.equals(comparator)) {
return (ImmutableSortedMultiset) NATURAL_EMPTY_MULTISET;
}
return new EmptyImmutableSortedMultiset<E>(comparator);
}
private final transient Comparator<? super E> comparator;
ImmutableSortedMultiset(Comparator<? super E> comparator) {
this.comparator = checkNotNull(comparator);
}
@Override
public Comparator<? super E> comparator() {
return comparator;
}
// Pretend the comparator can compare anything. If it turns out it can't
// compare two elements, it'll throw a CCE. Only methods that are specified to
// throw CCE should call this.
@SuppressWarnings("unchecked")
Comparator<Object> unsafeComparator() {
return (Comparator<Object>) comparator;
}
private transient Comparator<? super E> reverseComparator;
Comparator<? super E> reverseComparator() {
Comparator<? super E> result = reverseComparator;
if (result == null) {
return reverseComparator = Ordering.from(comparator).<E>reverse();
}
return result;
}
private transient ImmutableSortedSet<E> elementSet;
@Override
public ImmutableSortedSet<E> elementSet() {
ImmutableSortedSet<E> result = elementSet;
if (result == null) {
return elementSet = createElementSet();
}
return result;
}
abstract ImmutableSortedSet<E> createElementSet();
abstract ImmutableSortedSet<E> createDescendingElementSet();
transient ImmutableSortedMultiset<E> descendingMultiset;
@Override
public ImmutableSortedMultiset<E> descendingMultiset() {
ImmutableSortedMultiset<E> result = descendingMultiset;
if (result == null) {
return descendingMultiset = new DescendingImmutableSortedMultiset<E>(this);
}
return result;
}
abstract UnmodifiableIterator<Entry<E>> descendingEntryIterator();
/**
* {@inheritDoc}
*
* <p>This implementation is guaranteed to throw an {@link UnsupportedOperationException}.
*/
@Override
public final Entry<E> pollFirstEntry() {
throw new UnsupportedOperationException();
}
/**
* {@inheritDoc}
*
* <p>This implementation is guaranteed to throw an {@link UnsupportedOperationException}.
*/
@Override
public Entry<E> pollLastEntry() {
throw new UnsupportedOperationException();
}
@Override
public abstract ImmutableSortedMultiset<E> headMultiset(E upperBound, BoundType boundType);
@Override
public ImmutableSortedMultiset<E> subMultiset(
E lowerBound, BoundType lowerBoundType, E upperBound, BoundType upperBoundType) {
return tailMultiset(lowerBound, lowerBoundType).headMultiset(upperBound, upperBoundType);
}
@Override
public abstract ImmutableSortedMultiset<E> tailMultiset(E lowerBound, BoundType boundType);
/**
* Returns a builder that creates immutable sorted multisets with an explicit comparator. If the
* comparator has a more general type than the set being generated, such as creating a {@code
* SortedMultiset<Integer>} with a {@code Comparator<Number>}, use the {@link Builder}
* constructor instead.
*
* @throws NullPointerException if {@code comparator} is null
*/
public static <E> Builder<E> orderedBy(Comparator<E> comparator) {
return new Builder<E>(comparator);
}
/**
* Returns a builder that creates immutable sorted multisets whose elements are ordered by the
* reverse of their natural ordering.
*
* <p>Note: the type parameter {@code E} extends {@code Comparable<E>} rather than {@code
* Comparable<? super E>} as a workaround for javac <a
* href="http://bugs.sun.com/bugdatabase/view_bug.do?bug_id=6468354">bug 6468354</a>.
*/
public static <E extends Comparable<E>> Builder<E> reverseOrder() {
return new Builder<E>(Ordering.natural().reverse());
}
/**
* Returns a builder that creates immutable sorted multisets whose elements are ordered by their
* natural ordering. The sorted multisets use {@link Ordering#natural()} as the comparator. This
* method provides more type-safety than {@link #builder}, as it can be called only for classes
* that implement {@link Comparable}.
*
* <p>Note: the type parameter {@code E} extends {@code Comparable<E>} rather than {@code
* Comparable<? super E>} as a workaround for javac <a
* href="http://bugs.sun.com/bugdatabase/view_bug.do?bug_id=6468354">bug 6468354</a>.
*/
public static <E extends Comparable<E>> Builder<E> naturalOrder() {
return new Builder<E>(Ordering.natural());
}
/**
* A builder for creating immutable multiset instances, especially {@code public static final}
* multisets ("constant multisets"). Example:
*
* <pre> {@code
*
* public static final ImmutableSortedMultiset<Bean> BEANS =
* new ImmutableSortedMultiset.Builder<Bean>()
* .addCopies(Bean.COCOA, 4)
* .addCopies(Bean.GARDEN, 6)
* .addCopies(Bean.RED, 8)
* .addCopies(Bean.BLACK_EYED, 10)
* .build();}</pre>
*
* Builder instances can be reused; it is safe to call {@link #build} multiple times to build
* multiple multisets in series.
*/
public static class Builder<E> extends ImmutableMultiset.Builder<E> {
private final Comparator<? super E> comparator;
/**
* Creates a new builder. The returned builder is equivalent to the builder generated by
* {@link ImmutableSortedMultiset#orderedBy(Comparator)}.
*/
public Builder(Comparator<? super E> comparator) {
super(TreeMultiset.<E>create(comparator));
this.comparator = checkNotNull(comparator);
}
/**
* Adds {@code element} to the {@code ImmutableSortedMultiset}.
*
* @param element the element to add
* @return this {@code Builder} object
* @throws NullPointerException if {@code element} is null
*/
@Override
public Builder<E> add(E element) {
super.add(element);
return this;
}
/**
* Adds a number of occurrences of an element to this {@code ImmutableSortedMultiset}.
*
* @param element the element to add
* @param occurrences the number of occurrences of the element to add. May be zero, in which
* case no change will be made.
* @return this {@code Builder} object
* @throws NullPointerException if {@code element} is null
* @throws IllegalArgumentException if {@code occurrences} is negative, or if this operation
* would result in more than {@link Integer#MAX_VALUE} occurrences of the element
*/
@Override
public Builder<E> addCopies(E element, int occurrences) {
super.addCopies(element, occurrences);
return this;
}
/**
* Adds or removes the necessary occurrences of an element such that the element attains the
* desired count.
*
* @param element the element to add or remove occurrences of
* @param count the desired count of the element in this multiset
* @return this {@code Builder} object
* @throws NullPointerException if {@code element} is null
* @throws IllegalArgumentException if {@code count} is negative
*/
@Override
public Builder<E> setCount(E element, int count) {
super.setCount(element, count);
return this;
}
/**
* Adds each element of {@code elements} to the {@code ImmutableSortedMultiset}.
*
* @param elements the elements to add
* @return this {@code Builder} object
* @throws NullPointerException if {@code elements} is null or contains a null element
*/
@Override
public Builder<E> add(E... elements) {
super.add(elements);
return this;
}
/**
* Adds each element of {@code elements} to the {@code ImmutableSortedMultiset}.
*
* @param elements the {@code Iterable} to add to the {@code ImmutableSortedMultiset}
* @return this {@code Builder} object
* @throws NullPointerException if {@code elements} is null or contains a null element
*/
@Override
public Builder<E> addAll(Iterable<? extends E> elements) {
super.addAll(elements);
return this;
}
/**
* Adds each element of {@code elements} to the {@code ImmutableSortedMultiset}.
*
* @param elements the elements to add to the {@code ImmutableSortedMultiset}
* @return this {@code Builder} object
* @throws NullPointerException if {@code elements} is null or contains a null element
*/
@Override
public Builder<E> addAll(Iterator<? extends E> elements) {
super.addAll(elements);
return this;
}
/**
* Returns a newly-created {@code ImmutableSortedMultiset} based on the contents of the {@code
* Builder}.
*/
@Override
public ImmutableSortedMultiset<E> build() {
return copyOf(comparator, contents);
}
}
private static final class SerializedForm implements Serializable {
Comparator comparator;
Object[] elements;
int[] counts;
SerializedForm(SortedMultiset<?> multiset) {
this.comparator = multiset.comparator();
int n = multiset.entrySet().size();
elements = new Object[n];
counts = new int[n];
int i = 0;
for (Entry<?> entry : multiset.entrySet()) {
elements[i] = entry.getElement();
counts[i] = entry.getCount();
i++;
}
}
@SuppressWarnings("unchecked")
Object readResolve() {
int n = elements.length;
Builder<Object> builder = orderedBy(comparator);
for (int i = 0; i < n; i++) {
builder.addCopies(elements[i], counts[i]);
}
return builder.build();
}
}
@Override
Object writeReplace() {
return new SerializedForm(this);
}
}
| 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 java.util.Map;
import java.util.Set;
import javax.annotation.Nullable;
/**
* A collection similar to a {@code Map}, but which may associate multiple
* values with a single key. If you call {@link #put} twice, with the same key
* but different values, the multimap contains mappings from the key to both
* values.
*
* <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 modifiable, updating it can change the contents
* of those collections, and updating the collections will change the multimap.
* In contrast, {@link #replaceValues} and {@link #removeAll} return collections
* that are independent of subsequent multimap changes.
*
* <p>Depending on the implementation, a multimap may or may not allow duplicate
* key-value pairs. In other words, the multimap contents after adding the same
* key and value twice varies between implementations. In multimaps allowing
* duplicates, the multimap will contain two mappings, and {@code get} will
* return a collection that includes the value twice. In multimaps not
* supporting duplicates, the multimap will contain a single mapping from the
* key to the value, and {@code get} will return a collection that includes the
* value once.
*
* <p>All methods that alter the multimap are optional, and the views returned
* by the multimap may or may not be modifiable. When modification isn't
* supported, those methods will throw an {@link UnsupportedOperationException}.
*
* <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
* @param <K> the type of keys maintained by this multimap
* @param <V> the type of mapped values
* @since 2.0 (imported from Google Collections Library)
*/
@GwtCompatible
public interface Multimap<K, V> {
// Query Operations
/** Returns the number of key-value pairs in the multimap. */
int size();
/** Returns {@code true} if the multimap contains no key-value pairs. */
boolean isEmpty();
/**
* Returns {@code true} if the multimap contains any values for the specified
* key.
*
* @param key key to search for in multimap
*/
boolean containsKey(@Nullable Object key);
/**
* Returns {@code true} if the multimap contains the specified value for any
* key.
*
* @param value value to search for in multimap
*/
boolean containsValue(@Nullable Object value);
/**
* Returns {@code true} if the multimap contains the specified key-value pair.
*
* @param key key to search for in multimap
* @param value value to search for in multimap
*/
boolean containsEntry(@Nullable Object key, @Nullable Object value);
// Modification Operations
/**
* Stores a key-value pair in the multimap.
*
* <p>Some multimap implementations allow duplicate key-value pairs, in which
* case {@code put} always adds a new key-value pair and increases the
* multimap size by 1. Other implementations prohibit duplicates, and storing
* a key-value pair that's already in the multimap has no effect.
*
* @param key key to store in the multimap
* @param value value to store in the multimap
* @return {@code true} if the method increased the size of the multimap, or
* {@code false} if the multimap already contained the key-value pair and
* doesn't allow duplicates
*/
boolean put(@Nullable K key, @Nullable V value);
/**
* Removes a key-value pair from the multimap.
*
* @param key key of entry to remove from the multimap
* @param value value of entry to remove the multimap
* @return {@code true} if the multimap changed
*/
boolean remove(@Nullable Object key, @Nullable Object value);
// Bulk Operations
/**
* Stores a collection of values with the same key.
*
* @param key key to store in the multimap
* @param values values to store in the multimap
* @return {@code true} if the multimap changed
*/
boolean putAll(@Nullable K key, Iterable<? extends V> values);
/**
* Copies all of another multimap's key-value pairs into this multimap. The
* order in which the mappings are added is determined by
* {@code multimap.entries()}.
*
* @param multimap mappings to store in this multimap
* @return {@code true} if the multimap changed
*/
boolean putAll(Multimap<? extends K, ? extends V> multimap);
/**
* Stores a collection of values with the same key, replacing any existing
* values for that key.
*
* @param key key to store in the multimap
* @param values values to store in the multimap
* @return the collection of replaced values, or an empty collection if no
* values were previously associated with the key. The collection
* <i>may</i> be modifiable, but updating it will have no effect on the
* multimap.
*/
Collection<V> replaceValues(@Nullable K key, Iterable<? extends V> values);
/**
* Removes all values associated with a given key.
*
* @param key key of entries to remove from the multimap
* @return the collection of removed values, or an empty collection if no
* values were associated with the provided key. The collection
* <i>may</i> be modifiable, but updating it will have no effect on the
* multimap.
*/
Collection<V> removeAll(@Nullable Object key);
/**
* Removes all key-value pairs from the multimap.
*/
void clear();
// Views
/**
* Returns a collection view of all values associated with a key. If no
* mappings in the multimap have the provided key, an empty collection is
* returned.
*
* <p>Changes to the returned collection will update the underlying multimap,
* and vice versa.
*
* @param key key to search for in multimap
* @return the collection of values that the key maps to
*/
Collection<V> get(@Nullable K key);
/**
* Returns the set of all keys, each appearing once in the returned set.
* Changes to the returned set will update the underlying multimap, and vice
* versa.
*
* @return the collection of distinct keys
*/
Set<K> keySet();
/**
* Returns a collection, which may contain duplicates, of all keys. The number
* of times of key appears in the returned multiset equals the number of
* mappings the key has in the multimap. Changes to the returned multiset will
* update the underlying multimap, and vice versa.
*
* @return a multiset with keys corresponding to the distinct keys of the
* multimap and frequencies corresponding to the number of values that
* each key maps to
*/
Multiset<K> keys();
/**
* Returns a collection of all values in the multimap. Changes to the returned
* collection will update the underlying multimap, and vice versa.
*
* @return collection of values, which may include the same value multiple
* times if it occurs in multiple mappings
*/
Collection<V> values();
/**
* Returns a collection of all key-value pairs. Changes to the returned
* collection will update the underlying multimap, and vice versa. The entries
* collection does not support the {@code add} or {@code addAll} operations.
*
* @return collection of map entries consisting of key-value pairs
*/
Collection<Map.Entry<K, V>> entries();
/**
* Returns a map view that associates each key with the corresponding values
* in the multimap. Changes to the returned map, such as element removal, will
* update the underlying multimap. The map does not support {@code setValue()}
* on its entries, {@code put}, or {@code putAll}.
*
* <p>When passed a key that is present in the map, {@code
* asMap().get(Object)} has the same behavior as {@link #get}, returning a
* live collection. When passed a key that is not present, however, {@code
* asMap().get(Object)} returns {@code null} instead of an empty collection.
*
* @return a map view from a key to its collection of values
*/
Map<K, Collection<V>> asMap();
// Comparison and hashing
/**
* Compares the specified object with this multimap for equality. Two
* multimaps are equal when their map views, as returned by {@link #asMap},
* are also equal.
*
* <p>In general, two multimaps with identical key-value mappings may or may
* not be equal, depending on the implementation. For example, two
* {@link SetMultimap} instances with the same key-value mappings are equal,
* but equality of two {@link ListMultimap} instances depends on the ordering
* of the values for each key.
*
* <p>A non-empty {@link SetMultimap} cannot be equal to a non-empty
* {@link ListMultimap}, since their {@link #asMap} views contain unequal
* collections as values. However, any two empty multimaps are equal, because
* they both have empty {@link #asMap} views.
*/
@Override
boolean equals(@Nullable Object obj);
/**
* 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
int hashCode();
}
| 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.checkElementIndex;
import static com.google.common.base.Preconditions.checkPositionIndex;
import static com.google.common.base.Preconditions.checkPositionIndexes;
import com.google.common.annotations.GwtCompatible;
import java.util.Collection;
import java.util.List;
import java.util.NoSuchElementException;
import javax.annotation.Nullable;
/**
* An empty immutable list.
*
* @author Kevin Bourrillion
*/
@GwtCompatible(serializable = true, emulated = true)
final class EmptyImmutableList extends ImmutableList<Object> {
static final EmptyImmutableList INSTANCE = new EmptyImmutableList();
static final UnmodifiableListIterator<Object> ITERATOR =
new UnmodifiableListIterator<Object>() {
@Override public boolean hasNext() {
return false;
}
@Override public boolean hasPrevious() {
return false;
}
@Override public Object next() {
throw new NoSuchElementException();
}
@Override public int nextIndex() {
return 0;
}
@Override public Object previous() {
throw new NoSuchElementException();
}
@Override public int previousIndex() {
return -1;
}
};
private EmptyImmutableList() {}
@Override
public int size() {
return 0;
}
@Override public boolean isEmpty() {
return true;
}
@Override boolean isPartialView() {
return false;
}
@Override public boolean contains(Object target) {
return false;
}
@Override public UnmodifiableIterator<Object> iterator() {
return Iterators.emptyIterator();
}
private static final Object[] EMPTY_ARRAY = new Object[0];
@Override public Object[] toArray() {
return EMPTY_ARRAY;
}
@Override public <T> T[] toArray(T[] a) {
if (a.length > 0) {
a[0] = null;
}
return a;
}
@Override
public Object get(int index) {
// guaranteed to fail, but at least we get a consistent message
checkElementIndex(index, 0);
throw new AssertionError("unreachable");
}
@Override public int indexOf(@Nullable Object target) {
return -1;
}
@Override public int lastIndexOf(@Nullable Object target) {
return -1;
}
@Override public ImmutableList<Object> subList(int fromIndex, int toIndex) {
checkPositionIndexes(fromIndex, toIndex, 0);
return this;
}
@Override public ImmutableList<Object> reverse() {
return this;
}
@Override public UnmodifiableListIterator<Object> listIterator(){
return ITERATOR;
}
@Override public UnmodifiableListIterator<Object> listIterator(int start) {
checkPositionIndex(start, 0);
return ITERATOR;
}
@Override public boolean containsAll(Collection<?> targets) {
return targets.isEmpty();
}
@Override public boolean equals(@Nullable Object object) {
if (object instanceof List) {
List<?> that = (List<?>) object;
return that.isEmpty();
}
return false;
}
@Override public int hashCode() {
return 1;
}
@Override public String toString() {
return "[]";
}
Object readResolve() {
return INSTANCE; // preserve singleton property
}
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.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 java.io.Serializable;
import java.util.AbstractSet;
import java.util.Collection;
import java.util.Collections;
import java.util.Comparator;
import java.util.Iterator;
import java.util.List;
import java.util.NoSuchElementException;
import java.util.Set;
import java.util.SortedSet;
import javax.annotation.Nullable;
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.collect.Multiset.Entry;
import com.google.common.primitives.Ints;
/**
* Provides static utility methods for creating and working with {@link
* Multiset} instances.
*
* <p>See the Guava User Guide article on <a href=
* "http://code.google.com/p/guava-libraries/wiki/CollectionUtilitiesExplained#Multisets">
* {@code Multisets}</a>.
*
* @author Kevin Bourrillion
* @author Mike Bostock
* @author Louis Wasserman
* @since 2.0 (imported from Google Collections Library)
*/
@GwtCompatible
public final class Multisets {
private Multisets() {}
/**
* Returns an unmodifiable view of the specified multiset. Query operations on
* the returned multiset "read through" to the specified multiset, and
* attempts to modify the returned multiset result in an
* {@link UnsupportedOperationException}.
*
* <p>The returned multiset will be serializable if the specified multiset is
* serializable.
*
* @param multiset the multiset for which an unmodifiable view is to be
* generated
* @return an unmodifiable view of the multiset
*/
public static <E> Multiset<E> unmodifiableMultiset(
Multiset<? extends E> multiset) {
if (multiset instanceof UnmodifiableMultiset ||
multiset instanceof ImmutableMultiset) {
// Since it's unmodifiable, the covariant cast is safe
@SuppressWarnings("unchecked")
Multiset<E> result = (Multiset<E>) multiset;
return result;
}
return new UnmodifiableMultiset<E>(checkNotNull(multiset));
}
/**
* Simply returns its argument.
*
* @deprecated no need to use this
* @since 10.0
*/
@Deprecated public static <E> Multiset<E> unmodifiableMultiset(
ImmutableMultiset<E> multiset) {
return checkNotNull(multiset);
}
static class UnmodifiableMultiset<E>
extends ForwardingMultiset<E> implements Serializable {
final Multiset<? extends E> delegate;
UnmodifiableMultiset(Multiset<? extends E> delegate) {
this.delegate = delegate;
}
@SuppressWarnings("unchecked")
@Override protected Multiset<E> delegate() {
// This is safe because all non-covariant methods are overriden
return (Multiset<E>) delegate;
}
transient Set<E> elementSet;
Set<E> createElementSet() {
return Collections.<E>unmodifiableSet(delegate.elementSet());
}
@Override
public Set<E> elementSet() {
Set<E> es = elementSet;
return (es == null) ? elementSet = createElementSet() : es;
}
transient Set<Multiset.Entry<E>> entrySet;
@SuppressWarnings("unchecked")
@Override public Set<Multiset.Entry<E>> entrySet() {
Set<Multiset.Entry<E>> es = entrySet;
return (es == null)
// Safe because the returned set is made unmodifiable and Entry
// itself is readonly
? entrySet = (Set) Collections.unmodifiableSet(delegate.entrySet())
: es;
}
@SuppressWarnings("unchecked")
@Override public Iterator<E> iterator() {
// Safe because the returned Iterator is made unmodifiable
return (Iterator<E>) Iterators.unmodifiableIterator(delegate.iterator());
}
@Override public boolean add(E element) {
throw new UnsupportedOperationException();
}
@Override public int add(E element, int occurences) {
throw new UnsupportedOperationException();
}
@Override public boolean addAll(Collection<? extends E> elementsToAdd) {
throw new UnsupportedOperationException();
}
@Override public boolean remove(Object element) {
throw new UnsupportedOperationException();
}
@Override public int remove(Object element, int occurrences) {
throw new UnsupportedOperationException();
}
@Override public boolean removeAll(Collection<?> elementsToRemove) {
throw new UnsupportedOperationException();
}
@Override public boolean retainAll(Collection<?> elementsToRetain) {
throw new UnsupportedOperationException();
}
@Override public void clear() {
throw new UnsupportedOperationException();
}
@Override public int setCount(E element, int count) {
throw new UnsupportedOperationException();
}
@Override public boolean setCount(E element, int oldCount, int newCount) {
throw new UnsupportedOperationException();
}
private static final long serialVersionUID = 0;
}
/**
* Returns an unmodifiable view of the specified sorted multiset. Query
* operations on the returned multiset "read through" to the specified
* multiset, and attempts to modify the returned multiset result in an {@link
* UnsupportedOperationException}.
*
* <p>The returned multiset will be serializable if the specified multiset is
* serializable.
*
* @param sortedMultiset the sorted multiset for which an unmodifiable view is
* to be generated
* @return an unmodifiable view of the multiset
* @since 11.0
*/
@Beta
public static <E> SortedMultiset<E> unmodifiableSortedMultiset(
SortedMultiset<E> sortedMultiset) {
return new UnmodifiableSortedMultiset<E>(checkNotNull(sortedMultiset));
}
private static final class UnmodifiableSortedMultiset<E>
extends UnmodifiableMultiset<E> implements SortedMultiset<E> {
private UnmodifiableSortedMultiset(SortedMultiset<E> delegate) {
super(delegate);
}
@Override
protected SortedMultiset<E> delegate() {
return (SortedMultiset<E>) super.delegate();
}
@Override
public Comparator<? super E> comparator() {
return delegate().comparator();
}
@Override
SortedSet<E> createElementSet() {
return Collections.unmodifiableSortedSet(delegate().elementSet());
}
@Override
public SortedSet<E> elementSet() {
return (SortedSet<E>) super.elementSet();
}
private transient UnmodifiableSortedMultiset<E> descendingMultiset;
@Override
public SortedMultiset<E> descendingMultiset() {
UnmodifiableSortedMultiset<E> result = descendingMultiset;
if (result == null) {
result = new UnmodifiableSortedMultiset<E>(
delegate().descendingMultiset());
result.descendingMultiset = this;
return descendingMultiset = result;
}
return result;
}
@Override
public Entry<E> firstEntry() {
return delegate().firstEntry();
}
@Override
public Entry<E> lastEntry() {
return delegate().lastEntry();
}
@Override
public Entry<E> pollFirstEntry() {
throw new UnsupportedOperationException();
}
@Override
public Entry<E> pollLastEntry() {
throw new UnsupportedOperationException();
}
@Override
public SortedMultiset<E> headMultiset(E upperBound, BoundType boundType) {
return unmodifiableSortedMultiset(
delegate().headMultiset(upperBound, boundType));
}
@Override
public SortedMultiset<E> subMultiset(
E lowerBound, BoundType lowerBoundType,
E upperBound, BoundType upperBoundType) {
return unmodifiableSortedMultiset(delegate().subMultiset(
lowerBound, lowerBoundType, upperBound, upperBoundType));
}
@Override
public SortedMultiset<E> tailMultiset(E lowerBound, BoundType boundType) {
return unmodifiableSortedMultiset(
delegate().tailMultiset(lowerBound, boundType));
}
private static final long serialVersionUID = 0;
}
/**
* Returns an immutable multiset entry with the specified element and count.
* The entry will be serializable if {@code e} is.
*
* @param e the element to be associated with the returned entry
* @param n the count to be associated with the returned entry
* @throws IllegalArgumentException if {@code n} is negative
*/
public static <E> Multiset.Entry<E> immutableEntry(@Nullable E e, int n) {
return new ImmutableEntry<E>(e, n);
}
static final class ImmutableEntry<E> extends AbstractEntry<E> implements
Serializable {
@Nullable final E element;
final int count;
ImmutableEntry(@Nullable E element, int count) {
this.element = element;
this.count = count;
checkArgument(count >= 0);
}
@Override
@Nullable public E getElement() {
return element;
}
@Override
public int getCount() {
return count;
}
private static final long serialVersionUID = 0;
}
/**
* Returns a multiset view of the specified set. The multiset is backed by the
* set, so changes to the set are reflected in the multiset, and vice versa.
* If the set is modified while an iteration over the multiset is in progress
* (except through the iterator's own {@code remove} operation) the results of
* the iteration are undefined.
*
* <p>The multiset supports element removal, which removes the corresponding
* element from the set. It does not support the {@code add} or {@code addAll}
* operations, nor does it support the use of {@code setCount} to add
* elements.
*
* <p>The returned multiset will be serializable if the specified set is
* serializable. The multiset is threadsafe if the set is threadsafe.
*
* @param set the backing set for the returned multiset view
*/
static <E> Multiset<E> forSet(Set<E> set) {
return new SetMultiset<E>(set);
}
/** @see Multisets#forSet */
private static class SetMultiset<E> extends ForwardingCollection<E>
implements Multiset<E>, Serializable {
final Set<E> delegate;
SetMultiset(Set<E> set) {
delegate = checkNotNull(set);
}
@Override protected Set<E> delegate() {
return delegate;
}
@Override
public int count(Object element) {
return delegate.contains(element) ? 1 : 0;
}
@Override
public int add(E element, int occurrences) {
throw new UnsupportedOperationException();
}
@Override
public int remove(Object element, int occurrences) {
if (occurrences == 0) {
return count(element);
}
checkArgument(occurrences > 0);
return delegate.remove(element) ? 1 : 0;
}
transient Set<E> elementSet;
@Override
public Set<E> elementSet() {
Set<E> es = elementSet;
return (es == null) ? elementSet = new ElementSet() : es;
}
transient Set<Entry<E>> entrySet;
@Override public Set<Entry<E>> entrySet() {
Set<Entry<E>> es = entrySet;
if (es == null) {
es = entrySet = new EntrySet<E>() {
@Override Multiset<E> multiset() {
return SetMultiset.this;
}
@Override public Iterator<Entry<E>> iterator() {
return Iterators.transform(delegate.iterator(),
new Function<E, Entry<E>>() {
@Override public Entry<E> apply(E elem) {
return immutableEntry(elem, 1);
}
});
}
@Override public int size() {
return delegate.size();
}
};
}
return es;
}
@Override public boolean add(E o) {
throw new UnsupportedOperationException();
}
@Override public boolean addAll(Collection<? extends E> c) {
throw new UnsupportedOperationException();
}
@Override
public int setCount(E element, int count) {
checkNonnegative(count, "count");
if (count == count(element)) {
return count;
} else if (count == 0) {
remove(element);
return 1;
} else {
throw new UnsupportedOperationException();
}
}
@Override
public boolean setCount(E element, int oldCount, int newCount) {
return setCountImpl(this, element, oldCount, newCount);
}
@Override public boolean equals(@Nullable Object object) {
if (object instanceof Multiset) {
Multiset<?> that = (Multiset<?>) object;
return this.size() == that.size() && delegate.equals(that.elementSet());
}
return false;
}
@Override public int hashCode() {
int sum = 0;
for (E e : this) {
sum += ((e == null) ? 0 : e.hashCode()) ^ 1;
}
return sum;
}
/** @see SetMultiset#elementSet */
class ElementSet extends ForwardingSet<E> {
@Override protected Set<E> delegate() {
return delegate;
}
@Override public boolean add(E o) {
throw new UnsupportedOperationException();
}
@Override public boolean addAll(Collection<? extends E> c) {
throw new UnsupportedOperationException();
}
}
private static final long serialVersionUID = 0;
}
/**
* Returns the expected number of distinct elements given the specified
* elements. The number of distinct elements is only computed if {@code
* elements} is an instance of {@code Multiset}; otherwise the default value
* of 11 is returned.
*/
static int inferDistinctElements(Iterable<?> elements) {
if (elements instanceof Multiset) {
return ((Multiset<?>) elements).elementSet().size();
}
return 11; // initial capacity will be rounded up to 16
}
/**
* Returns an unmodifiable <b>view</b> of the intersection of two multisets.
* An element's count in the multiset is the smaller of its counts in the two
* backing multisets. The iteration order of the returned multiset matches the
* element set of {@code multiset1}, with repeated occurrences of the same
* element appearing consecutively.
*
* <p>Results are undefined if {@code multiset1} and {@code multiset2} are
* based on different equivalence relations (as {@code HashMultiset} and
* {@code TreeMultiset} are).
*
* @since 2.0
*/
public static <E> Multiset<E> intersection(
final Multiset<E> multiset1, final Multiset<?> multiset2) {
checkNotNull(multiset1);
checkNotNull(multiset2);
return new AbstractMultiset<E>() {
@Override
public int count(Object element) {
int count1 = multiset1.count(element);
return (count1 == 0) ? 0 : Math.min(count1, multiset2.count(element));
}
@Override
Set<E> createElementSet() {
return Sets.intersection(
multiset1.elementSet(), multiset2.elementSet());
}
@Override
Iterator<Entry<E>> entryIterator() {
final Iterator<Entry<E>> iterator1 = multiset1.entrySet().iterator();
return new AbstractIterator<Entry<E>>() {
@Override
protected Entry<E> computeNext() {
while (iterator1.hasNext()) {
Entry<E> entry1 = iterator1.next();
E element = entry1.getElement();
int count = Math.min(entry1.getCount(), multiset2.count(element));
if (count > 0) {
return Multisets.immutableEntry(element, count);
}
}
return endOfData();
}
};
}
@Override
int distinctElements() {
return elementSet().size();
}
};
}
/**
* Returns {@code true} if {@code subMultiset.count(o) <=
* superMultiset.count(o)} for all {@code o}.
*
* @since 10.0
*/
@Beta
public static boolean containsOccurrences(
Multiset<?> superMultiset, Multiset<?> subMultiset) {
checkNotNull(superMultiset);
checkNotNull(subMultiset);
for (Entry<?> entry : subMultiset.entrySet()) {
int superCount = superMultiset.count(entry.getElement());
if (superCount < entry.getCount()) {
return false;
}
}
return true;
}
/**
* Modifies {@code multisetToModify} so that its count for an element
* {@code e} is at most {@code multisetToRetain.count(e)}.
*
* <p>To be precise, {@code multisetToModify.count(e)} is set to
* {@code Math.min(multisetToModify.count(e),
* multisetToRetain.count(e))}. This is similar to
* {@link #intersection(Multiset, Multiset) intersection}
* {@code (multisetToModify, multisetToRetain)}, but mutates
* {@code multisetToModify} instead of returning a view.
*
* <p>In contrast, {@code multisetToModify.retainAll(multisetToRetain)} keeps
* all occurrences of elements that appear at all in {@code
* multisetToRetain}, and deletes all occurrences of all other elements.
*
* @return {@code true} if {@code multisetToModify} was changed as a result
* of this operation
* @since 10.0
*/
@Beta public static boolean retainOccurrences(Multiset<?> multisetToModify,
Multiset<?> multisetToRetain) {
return retainOccurrencesImpl(multisetToModify, multisetToRetain);
}
/**
* Delegate implementation which cares about the element type.
*/
private static <E> boolean retainOccurrencesImpl(
Multiset<E> multisetToModify, Multiset<?> occurrencesToRetain) {
checkNotNull(multisetToModify);
checkNotNull(occurrencesToRetain);
// Avoiding ConcurrentModificationExceptions is tricky.
Iterator<Entry<E>> entryIterator = multisetToModify.entrySet().iterator();
boolean changed = false;
while (entryIterator.hasNext()) {
Entry<E> entry = entryIterator.next();
int retainCount = occurrencesToRetain.count(entry.getElement());
if (retainCount == 0) {
entryIterator.remove();
changed = true;
} else if (retainCount < entry.getCount()) {
multisetToModify.setCount(entry.getElement(), retainCount);
changed = true;
}
}
return changed;
}
/**
* For each occurrence of an element {@code e} in {@code occurrencesToRemove},
* removes one occurrence of {@code e} in {@code multisetToModify}.
*
* <p>Equivalently, this method modifies {@code multisetToModify} so that
* {@code multisetToModify.count(e)} is set to
* {@code Math.max(0, multisetToModify.count(e) -
* occurrencesToRemove.count(e))}.
*
* <p>This is <i>not</i> the same as {@code multisetToModify.}
* {@link Multiset#removeAll removeAll}{@code (occurrencesToRemove)}, which
* removes all occurrences of elements that appear in
* {@code occurrencesToRemove}. However, this operation <i>is</i> equivalent
* to, albeit more efficient than, the following: <pre> {@code
*
* for (E e : occurrencesToRemove) {
* multisetToModify.remove(e);
* }}</pre>
*
* @return {@code true} if {@code multisetToModify} was changed as a result of
* this operation
* @since 10.0
*/
@Beta public static boolean removeOccurrences(
Multiset<?> multisetToModify, Multiset<?> occurrencesToRemove) {
return removeOccurrencesImpl(multisetToModify, occurrencesToRemove);
}
/**
* Delegate that cares about the element types in occurrencesToRemove.
*/
private static <E> boolean removeOccurrencesImpl(
Multiset<E> multisetToModify, Multiset<?> occurrencesToRemove) {
// TODO(user): generalize to removing an Iterable, perhaps
checkNotNull(multisetToModify);
checkNotNull(occurrencesToRemove);
boolean changed = false;
Iterator<Entry<E>> entryIterator = multisetToModify.entrySet().iterator();
while (entryIterator.hasNext()) {
Entry<E> entry = entryIterator.next();
int removeCount = occurrencesToRemove.count(entry.getElement());
if (removeCount >= entry.getCount()) {
entryIterator.remove();
changed = true;
} else if (removeCount > 0) {
multisetToModify.remove(entry.getElement(), removeCount);
changed = true;
}
}
return changed;
}
/**
* Implementation of the {@code equals}, {@code hashCode}, and
* {@code toString} methods of {@link Multiset.Entry}.
*/
abstract static class AbstractEntry<E> implements Multiset.Entry<E> {
/**
* Indicates whether an object equals this entry, following the behavior
* specified in {@link Multiset.Entry#equals}.
*/
@Override public boolean equals(@Nullable Object object) {
if (object instanceof Multiset.Entry) {
Multiset.Entry<?> that = (Multiset.Entry<?>) object;
return this.getCount() == that.getCount()
&& Objects.equal(this.getElement(), that.getElement());
}
return false;
}
/**
* Return this entry's hash code, following the behavior specified in
* {@link Multiset.Entry#hashCode}.
*/
@Override public int hashCode() {
E e = getElement();
return ((e == null) ? 0 : e.hashCode()) ^ getCount();
}
/**
* Returns a string representation of this multiset entry. The string
* representation consists of the associated element if the associated count
* is one, and otherwise the associated element followed by the characters
* " x " (space, x and space) followed by the count. Elements and counts are
* converted to strings as by {@code String.valueOf}.
*/
@Override public String toString() {
String text = String.valueOf(getElement());
int n = getCount();
return (n == 1) ? text : (text + " x " + n);
}
}
/**
* An implementation of {@link Multiset#equals}.
*/
static boolean equalsImpl(Multiset<?> multiset, @Nullable Object object) {
if (object == multiset) {
return true;
}
if (object instanceof Multiset) {
Multiset<?> that = (Multiset<?>) object;
/*
* We can't simply check whether the entry sets are equal, since that
* approach fails when a TreeMultiset has a comparator that returns 0
* when passed unequal elements.
*/
if (multiset.size() != that.size()
|| multiset.entrySet().size() != that.entrySet().size()) {
return false;
}
for (Entry<?> entry : that.entrySet()) {
if (multiset.count(entry.getElement()) != entry.getCount()) {
return false;
}
}
return true;
}
return false;
}
/**
* An implementation of {@link Multiset#addAll}.
*/
static <E> boolean addAllImpl(
Multiset<E> self, Collection<? extends E> elements) {
if (elements.isEmpty()) {
return false;
}
if (elements instanceof Multiset) {
Multiset<? extends E> that = cast(elements);
for (Entry<? extends E> entry : that.entrySet()) {
self.add(entry.getElement(), entry.getCount());
}
} else {
Iterators.addAll(self, elements.iterator());
}
return true;
}
/**
* An implementation of {@link Multiset#removeAll}.
*/
static boolean removeAllImpl(
Multiset<?> self, Collection<?> elementsToRemove) {
Collection<?> collection = (elementsToRemove instanceof Multiset)
? ((Multiset<?>) elementsToRemove).elementSet() : elementsToRemove;
return self.elementSet().removeAll(collection);
}
/**
* An implementation of {@link Multiset#retainAll}.
*/
static boolean retainAllImpl(
Multiset<?> self, Collection<?> elementsToRetain) {
Collection<?> collection = (elementsToRetain instanceof Multiset)
? ((Multiset<?>) elementsToRetain).elementSet() : elementsToRetain;
return self.elementSet().retainAll(collection);
}
/**
* An implementation of {@link Multiset#setCount(Object, int)}.
*/
static <E> int setCountImpl(Multiset<E> self, E element, int count) {
checkNonnegative(count, "count");
int oldCount = self.count(element);
int delta = count - oldCount;
if (delta > 0) {
self.add(element, delta);
} else if (delta < 0) {
self.remove(element, -delta);
}
return oldCount;
}
/**
* An implementation of {@link Multiset#setCount(Object, int, int)}.
*/
static <E> boolean setCountImpl(
Multiset<E> self, E element, int oldCount, int newCount) {
checkNonnegative(oldCount, "oldCount");
checkNonnegative(newCount, "newCount");
if (self.count(element) == oldCount) {
self.setCount(element, newCount);
return true;
} else {
return false;
}
}
static abstract class ElementSet<E> extends AbstractSet<E> {
abstract Multiset<E> multiset();
@Override public void clear() {
multiset().clear();
}
@Override public boolean contains(Object o) {
return multiset().contains(o);
}
@Override public boolean containsAll(Collection<?> c) {
return multiset().containsAll(c);
}
@Override public boolean isEmpty() {
return multiset().isEmpty();
}
@Override public Iterator<E> iterator() {
return Iterators.transform(multiset().entrySet().iterator(),
new Function<Entry<E>, E>() {
@Override public E apply(Entry<E> entry) {
return entry.getElement();
}
});
}
@Override
public boolean remove(Object o) {
int count = multiset().count(o);
if (count > 0) {
multiset().remove(o, count);
return true;
}
return false;
}
@Override public int size() {
return multiset().entrySet().size();
}
}
static abstract class EntrySet<E> extends AbstractSet<Entry<E>>{
abstract Multiset<E> multiset();
@Override public boolean contains(@Nullable Object o) {
if (o instanceof Entry) {
@SuppressWarnings("cast")
Entry<?> entry = (Entry<?>) o;
if (entry.getCount() <= 0) {
return false;
}
int count = multiset().count(entry.getElement());
return count == entry.getCount();
}
return false;
}
@SuppressWarnings("cast")
@Override public boolean remove(Object o) {
return contains(o)
&& multiset().elementSet().remove(((Entry<?>) o).getElement());
}
@Override public void clear() {
multiset().clear();
}
}
/**
* An implementation of {@link Multiset#iterator}.
*/
static <E> Iterator<E> iteratorImpl(Multiset<E> multiset) {
return new MultisetIteratorImpl<E>(
multiset, multiset.entrySet().iterator());
}
static final class MultisetIteratorImpl<E> implements Iterator<E> {
private final Multiset<E> multiset;
private final Iterator<Entry<E>> entryIterator;
private Entry<E> currentEntry;
/** Count of subsequent elements equal to current element */
private int laterCount;
/** Count of all elements equal to current element */
private int totalCount;
private boolean canRemove;
MultisetIteratorImpl(
Multiset<E> multiset, Iterator<Entry<E>> entryIterator) {
this.multiset = multiset;
this.entryIterator = entryIterator;
}
@Override
public boolean hasNext() {
return laterCount > 0 || entryIterator.hasNext();
}
@Override
public E next() {
if (!hasNext()) {
throw new NoSuchElementException();
}
if (laterCount == 0) {
currentEntry = entryIterator.next();
totalCount = laterCount = currentEntry.getCount();
}
laterCount--;
canRemove = true;
return currentEntry.getElement();
}
@Override
public void remove() {
checkState(
canRemove, "no calls to next() since the last call to remove()");
if (totalCount == 1) {
entryIterator.remove();
} else {
multiset.remove(currentEntry.getElement());
}
totalCount--;
canRemove = false;
}
}
/**
* An implementation of {@link Multiset#size}.
*/
static int sizeImpl(Multiset<?> multiset) {
long size = 0;
for (Entry<?> entry : multiset.entrySet()) {
size += entry.getCount();
}
return Ints.saturatedCast(size);
}
static void checkNonnegative(int count, String name) {
checkArgument(count >= 0, "%s cannot be negative: %s", name, count);
}
/**
* Used to avoid http://bugs.sun.com/view_bug.do?bug_id=6558557
*/
static <T> Multiset<T> cast(Iterable<T> iterable) {
return (Multiset<T>) iterable;
}
private static final Ordering<Entry<?>> DECREASING_COUNT_ORDERING = new Ordering<Entry<?>>() {
@Override
public int compare(Entry<?> entry1, Entry<?> entry2) {
return Ints.compare(entry2.getCount(), entry1.getCount());
}
};
/**
* Returns a copy of {@code multiset} as an {@link ImmutableMultiset} whose iteration order is
* highest count first, with ties broken by the iteration order of the original multiset.
*
* @since 11.0
*/
@Beta
public static <E> ImmutableMultiset<E> copyHighestCountFirst(Multiset<E> multiset) {
List<Entry<E>> sortedEntries =
Multisets.DECREASING_COUNT_ORDERING.sortedCopy(multiset.entrySet());
return ImmutableMultiset.copyFromEntries(sortedEntries);
}
}
| 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 java.util.Map;
import java.util.Set;
import java.util.SortedMap;
import java.util.SortedSet;
/**
* Interface that extends {@code Table} and whose rows are sorted.
*
* <p>The {@link #rowKeySet} method returns a {@link SortedSet} and the {@link
* #rowMap} method returns a {@link SortedMap}, instead of the {@link Set} and
* {@link Map} specified by the {@link Table} interface.
*
* @author Warren Dukes
* @since 8.0
*/
@GwtCompatible
@Beta
public interface RowSortedTable<R, C, V> extends Table<R, C, V> {
/**
* {@inheritDoc}
*
* <p>This method returns a {@link SortedSet}, instead of the {@code Set}
* specified in the {@link Table} interface.
*/
@Override SortedSet<R> rowKeySet();
/**
* {@inheritDoc}
*
* <p>This method returns a {@link SortedMap}, instead of the {@code Map}
* specified in the {@link Table} interface.
*/
@Override SortedMap<R, Map<C, V>> rowMap();
}
| 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.GwtIncompatible;
import java.io.IOException;
import java.io.ObjectInputStream;
import java.io.ObjectOutputStream;
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));
}
/**
* @serialData the number of distinct elements, the first element, its count,
* the second element, its count, and so on
*/
@GwtIncompatible("java.io.ObjectOutputStream")
private void writeObject(ObjectOutputStream stream) throws IOException {
stream.defaultWriteObject();
Serialization.writeMultiset(this, stream);
}
@GwtIncompatible("java.io.ObjectInputStream")
private void readObject(ObjectInputStream stream)
throws IOException, ClassNotFoundException {
stream.defaultReadObject();
int distinctElements = Serialization.readCount(stream);
setBackingMap(
Maps.<E, Count>newHashMapWithExpectedSize(distinctElements));
Serialization.populateMultiset(this, stream, distinctElements);
}
@GwtIncompatible("Not needed in emulated source.")
private static final long serialVersionUID = 0;
}
| Java |
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