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

This codec de/encodes from bytes to bytes.

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,
 _is_text_encoding=False,
 )