| 1 | """ Python 'bz2_codec' Codec - bz2 compression encoding
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| 2 |
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| 3 | Unlike most of the other codecs which target Unicode, this codec
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| 4 | will return Python string objects for both encode and decode.
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| 5 |
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| 6 | Adapted by Raymond Hettinger from zlib_codec.py which was written
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| 7 | by Marc-Andre Lemburg (mal@lemburg.com).
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| 8 |
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| 9 | """
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| 10 | import codecs
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| 11 | import bz2 # this codec needs the optional bz2 module !
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| 12 |
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| 13 | ### Codec APIs
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| 14 |
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| 15 | def bz2_encode(input,errors='strict'):
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| 16 |
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| 17 | """ Encodes the object input and returns a tuple (output
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| 18 | object, length consumed).
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| 19 |
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| 20 | errors defines the error handling to apply. It defaults to
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| 21 | 'strict' handling which is the only currently supported
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| 22 | error handling for this codec.
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| 23 |
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| 24 | """
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| 25 | assert errors == 'strict'
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| 26 | output = bz2.compress(input)
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| 27 | return (output, len(input))
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| 28 |
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| 29 | def bz2_decode(input,errors='strict'):
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| 30 |
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| 31 | """ Decodes the object input and returns a tuple (output
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| 32 | object, length consumed).
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| 33 |
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| 34 | input must be an object which provides the bf_getreadbuf
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| 35 | buffer slot. Python strings, buffer objects and memory
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| 36 | mapped files are examples of objects providing this slot.
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| 37 |
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| 38 | errors defines the error handling to apply. It defaults to
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| 39 | 'strict' handling which is the only currently supported
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| 40 | error handling for this codec.
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| 41 |
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| 42 | """
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| 43 | assert errors == 'strict'
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| 44 | output = bz2.decompress(input)
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| 45 | return (output, len(input))
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| 46 |
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| 47 | class Codec(codecs.Codec):
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| 48 |
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| 49 | def encode(self, input, errors='strict'):
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| 50 | return bz2_encode(input, errors)
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| 51 | def decode(self, input, errors='strict'):
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| 52 | return bz2_decode(input, errors)
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| 53 |
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| 54 | class IncrementalEncoder(codecs.IncrementalEncoder):
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| 55 | def __init__(self, errors='strict'):
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| 56 | assert errors == 'strict'
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| 57 | self.errors = errors
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| 58 | self.compressobj = bz2.BZ2Compressor()
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| 59 |
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| 60 | def encode(self, input, final=False):
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| 61 | if final:
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| 62 | c = self.compressobj.compress(input)
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| 63 | return c + self.compressobj.flush()
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| 64 | else:
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| 65 | return self.compressobj.compress(input)
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| 66 |
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| 67 | def reset(self):
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| 68 | self.compressobj = bz2.BZ2Compressor()
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| 69 |
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| 70 | class IncrementalDecoder(codecs.IncrementalDecoder):
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| 71 | def __init__(self, errors='strict'):
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| 72 | assert errors == 'strict'
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| 73 | self.errors = errors
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| 74 | self.decompressobj = bz2.BZ2Decompressor()
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| 75 |
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| 76 | def decode(self, input, final=False):
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| 77 | try:
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| 78 | return self.decompressobj.decompress(input)
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| 79 | except EOFError:
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| 80 | return ''
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| 81 |
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| 82 | def reset(self):
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| 83 | self.decompressobj = bz2.BZ2Decompressor()
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| 84 |
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| 85 | class StreamWriter(Codec,codecs.StreamWriter):
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| 86 | pass
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| 87 |
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| 88 | class StreamReader(Codec,codecs.StreamReader):
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| 89 | pass
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| 90 |
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| 91 | ### encodings module API
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| 92 |
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| 93 | def getregentry():
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| 94 | return codecs.CodecInfo(
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| 95 | name="bz2",
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| 96 | encode=bz2_encode,
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| 97 | decode=bz2_decode,
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| 98 | incrementalencoder=IncrementalEncoder,
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| 99 | incrementaldecoder=IncrementalDecoder,
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| 100 | streamwriter=StreamWriter,
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| 101 | streamreader=StreamReader,
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| 102 | )
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