"""Python 'zlib_codec' Codec - zlib compression encoding.

This codec de/encodes from bytes to bytes.

Written by Marc-Andre Lemburg ([email protected]).
"""

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,
_is_text_encoding=False,
)