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77 lines
2.2 KiB
Python
77 lines
2.2 KiB
Python
"""Python 'zlib_codec' Codec - zlib compression encoding.
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This codec de/encodes from bytes to bytes and is therefore usable with
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bytes.transform() and bytes.untransform().
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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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assert errors == 'strict'
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return (zlib.compress(input), len(input))
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def zlib_decode(input, errors='strict'):
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assert errors == 'strict'
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return (zlib.decompress(input), 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 __init__(self, errors='strict'):
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assert errors == 'strict'
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self.errors = errors
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self.compressobj = zlib.compressobj()
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def encode(self, input, final=False):
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if final:
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c = self.compressobj.compress(input)
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return c + self.compressobj.flush()
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else:
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return self.compressobj.compress(input)
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def reset(self):
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self.compressobj = zlib.compressobj()
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class IncrementalDecoder(codecs.IncrementalDecoder):
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def __init__(self, errors='strict'):
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assert errors == 'strict'
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self.errors = errors
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self.decompressobj = zlib.decompressobj()
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def decode(self, input, final=False):
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if final:
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c = self.decompressobj.decompress(input)
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return c + self.decompressobj.flush()
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else:
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return self.decompressobj.decompress(input)
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def reset(self):
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self.decompressobj = zlib.decompressobj()
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class StreamWriter(Codec, codecs.StreamWriter):
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charbuffertype = bytes
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class StreamReader(Codec, codecs.StreamReader):
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charbuffertype = bytes
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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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