103 lines
2.9 KiB
Python
103 lines
2.9 KiB
Python
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""" Python 'bz2_codec' Codec - bz2 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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Adapted by Raymond Hettinger from zlib_codec.py which was written
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by Marc-Andre Lemburg (mal@lemburg.com).
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"""
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import codecs
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import bz2 # this codec needs the optional bz2 module !
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### Codec APIs
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def bz2_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 = bz2.compress(input)
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return (output, len(input))
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def bz2_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 = bz2.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 bz2_encode(input, errors)
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def decode(self, input, errors='strict'):
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return bz2_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 = bz2.BZ2Compressor()
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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 = bz2.BZ2Compressor()
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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 = bz2.BZ2Decompressor()
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def decode(self, input, final=False):
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try:
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return self.decompressobj.decompress(input)
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except EOFError:
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return ''
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def reset(self):
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self.decompressobj = bz2.BZ2Decompressor()
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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="bz2",
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encode=bz2_encode,
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decode=bz2_decode,
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incrementalencoder=IncrementalEncoder,
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incrementaldecoder=IncrementalDecoder,
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streamwriter=StreamWriter,
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streamreader=StreamReader,
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)
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