text
stringlengths
0
828
if v == 0:
break
return num_bytes"
637,"def decode_varint(f, max_bytes=4):
""""""Decode variable integer using algorithm similar to that described
in MQTT Version 3.1.1 line 297.
Parameters
----------
f: file
Object with a read method.
max_bytes: int or None
If a varint cannot be constructed using `max_bytes` or fewer
from f then raises a `DecodeError`. If None then there is no
maximum number of bytes.
Raises
-------
DecodeError
When length is greater than max_bytes.
UnderflowDecodeError
When file ends before enough bytes can be read to construct the
varint.
Returns
-------
int
Number of bytes consumed.
int
Value extracted from `f`.
""""""
num_bytes_consumed = 0
value = 0
m = 1
while True:
buf = f.read(1)
if len(buf) == 0:
raise UnderflowDecodeError()
(u8,) = FIELD_U8.unpack(buf)
value += (u8 & 0x7f) * m
m *= 0x80
num_bytes_consumed += 1
if u8 & 0x80 == 0:
# No further bytes
break
elif max_bytes is not None and num_bytes_consumed >= max_bytes:
raise DecodeError('Variable integer contained more than maximum bytes ({}).'.format(max_bytes))
return num_bytes_consumed, value"
638,"def unpack(self, struct):
""""""Read as many bytes as are required to extract struct then
unpack and return a tuple of the values.
Raises
------
UnderflowDecodeError
Raised when a read failed to extract enough bytes from the
underlying stream to extract the bytes.
Parameters
----------
struct: struct.Struct
Returns
-------
tuple
Tuple of extracted values.
""""""
v = struct.unpack(self.read(struct.size))
return v"
639,"def unpack_utf8(self):
""""""Decode a utf-8 string encoded as described in MQTT Version
3.1.1 section 1.5.3 line 177. This is a 16-bit unsigned length
followed by a utf-8 encoded string.
Raises
------
UnderflowDecodeError
Raised when a read failed to extract enough bytes from the
underlying stream to decode the string.
DecodeError
When any code point in the utf-8 string is invalid.
Returns
-------
int
Number of bytes consumed.
str
A string utf-8 decoded from the underlying stream.
""""""
num_bytes_consumed, s = decode_utf8(self.__f)
self.__num_bytes_consumed += num_bytes_consumed
return num_bytes_consumed, s"
640,"def unpack_bytes(self):