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abb02e5994
of tuple) that provides incremental decoders and encoders (a way to use stateful codecs without the stream API). Functions codecs.getincrementaldecoder() and codecs.getincrementalencoder() have been added.
80 lines
2.3 KiB
Python
80 lines
2.3 KiB
Python
""" Python 'zlib_codec' Codec - zlib compression encoding
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Unlike most of the other codecs which target Unicode, this codec
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will return Python string objects for both encode and decode.
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Written by Marc-Andre Lemburg (mal@lemburg.com).
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"""
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import codecs
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import zlib # this codec needs the optional zlib module !
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### Codec APIs
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def zlib_encode(input,errors='strict'):
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""" Encodes the object input and returns a tuple (output
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object, length consumed).
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errors defines the error handling to apply. It defaults to
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'strict' handling which is the only currently supported
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error handling for this codec.
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"""
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assert errors == 'strict'
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output = zlib.compress(input)
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return (output, len(input))
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def zlib_decode(input,errors='strict'):
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""" Decodes the object input and returns a tuple (output
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object, length consumed).
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input must be an object which provides the bf_getreadbuf
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buffer slot. Python strings, buffer objects and memory
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mapped files are examples of objects providing this slot.
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errors defines the error handling to apply. It defaults to
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'strict' handling which is the only currently supported
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error handling for this codec.
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"""
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assert errors == 'strict'
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output = zlib.decompress(input)
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return (output, len(input))
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class Codec(codecs.Codec):
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def encode(self, input, errors='strict'):
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return zlib_encode(input, errors)
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def decode(self, input, errors='strict'):
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return zlib_decode(input, errors)
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class IncrementalEncoder(codecs.IncrementalEncoder):
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def encode(self, input, final=False):
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assert self.errors == 'strict'
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return zlib.compress(input)
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class IncrementalDecoder(codecs.IncrementalDecoder):
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def decode(self, input, final=False):
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assert self.errors == 'strict'
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return zlib.decompress(input)
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class StreamWriter(Codec,codecs.StreamWriter):
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pass
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class StreamReader(Codec,codecs.StreamReader):
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pass
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### encodings module API
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def getregentry():
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return codecs.CodecInfo(
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name='zlib',
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encode=zlib_encode,
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decode=zlib_decode,
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incrementalencoder=IncrementalEncoder,
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incrementaldecoder=IncrementalDecoder,
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streamreader=StreamReader,
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streamwriter=StreamWriter,
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)
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