mirror of
https://github.com/python/cpython.git
synced 2024-12-17 22:05:04 +08:00
78 lines
2.2 KiB
Python
78 lines
2.2 KiB
Python
"""Python 'zlib_codec' Codec - zlib compression encoding.
|
|
|
|
This codec de/encodes from bytes to bytes and is therefore usable with
|
|
bytes.transform() and bytes.untransform().
|
|
|
|
Written by Marc-Andre Lemburg (mal@lemburg.com).
|
|
"""
|
|
|
|
import codecs
|
|
import zlib # this codec needs the optional zlib module !
|
|
|
|
### Codec APIs
|
|
|
|
def zlib_encode(input, errors='strict'):
|
|
assert errors == 'strict'
|
|
return (zlib.compress(input), len(input))
|
|
|
|
def zlib_decode(input, errors='strict'):
|
|
assert errors == 'strict'
|
|
return (zlib.decompress(input), len(input))
|
|
|
|
class Codec(codecs.Codec):
|
|
def encode(self, input, errors='strict'):
|
|
return zlib_encode(input, errors)
|
|
def decode(self, input, errors='strict'):
|
|
return zlib_decode(input, errors)
|
|
|
|
class IncrementalEncoder(codecs.IncrementalEncoder):
|
|
def __init__(self, errors='strict'):
|
|
assert errors == 'strict'
|
|
self.errors = errors
|
|
self.compressobj = zlib.compressobj()
|
|
|
|
def encode(self, input, final=False):
|
|
if final:
|
|
c = self.compressobj.compress(input)
|
|
return c + self.compressobj.flush()
|
|
else:
|
|
return self.compressobj.compress(input)
|
|
|
|
def reset(self):
|
|
self.compressobj = zlib.compressobj()
|
|
|
|
class IncrementalDecoder(codecs.IncrementalDecoder):
|
|
def __init__(self, errors='strict'):
|
|
assert errors == 'strict'
|
|
self.errors = errors
|
|
self.decompressobj = zlib.decompressobj()
|
|
|
|
def decode(self, input, final=False):
|
|
if final:
|
|
c = self.decompressobj.decompress(input)
|
|
return c + self.decompressobj.flush()
|
|
else:
|
|
return self.decompressobj.decompress(input)
|
|
|
|
def reset(self):
|
|
self.decompressobj = zlib.decompressobj()
|
|
|
|
class StreamWriter(Codec, codecs.StreamWriter):
|
|
charbuffertype = bytes
|
|
|
|
class StreamReader(Codec, codecs.StreamReader):
|
|
charbuffertype = bytes
|
|
|
|
### encodings module API
|
|
|
|
def getregentry():
|
|
return codecs.CodecInfo(
|
|
name='zlib',
|
|
encode=zlib_encode,
|
|
decode=zlib_decode,
|
|
incrementalencoder=IncrementalEncoder,
|
|
incrementaldecoder=IncrementalDecoder,
|
|
streamreader=StreamReader,
|
|
streamwriter=StreamWriter,
|
|
)
|