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1 """Python 'bz2_codec' Codec - bz2 compression encoding.
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2
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3 This codec de/encodes from bytes to bytes and is therefore usable with
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4 bytes.transform() and bytes.untransform().
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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 assert errors == 'strict'
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17 return (bz2.compress(input), len(input))
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18
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19 def bz2_decode(input, errors='strict'):
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20 assert errors == 'strict'
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21 return (bz2.decompress(input), len(input))
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22
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23 class Codec(codecs.Codec):
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24 def encode(self, input, errors='strict'):
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25 return bz2_encode(input, errors)
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26 def decode(self, input, errors='strict'):
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27 return bz2_decode(input, errors)
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28
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29 class IncrementalEncoder(codecs.IncrementalEncoder):
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30 def __init__(self, errors='strict'):
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31 assert errors == 'strict'
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32 self.errors = errors
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33 self.compressobj = bz2.BZ2Compressor()
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34
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35 def encode(self, input, final=False):
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36 if final:
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37 c = self.compressobj.compress(input)
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38 return c + self.compressobj.flush()
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39 else:
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40 return self.compressobj.compress(input)
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41
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42 def reset(self):
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43 self.compressobj = bz2.BZ2Compressor()
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44
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45 class IncrementalDecoder(codecs.IncrementalDecoder):
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46 def __init__(self, errors='strict'):
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47 assert errors == 'strict'
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48 self.errors = errors
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49 self.decompressobj = bz2.BZ2Decompressor()
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50
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51 def decode(self, input, final=False):
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52 try:
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53 return self.decompressobj.decompress(input)
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54 except EOFError:
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55 return ''
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56
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57 def reset(self):
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58 self.decompressobj = bz2.BZ2Decompressor()
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59
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60 class StreamWriter(Codec, codecs.StreamWriter):
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61 charbuffertype = bytes
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62
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63 class StreamReader(Codec, codecs.StreamReader):
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64 charbuffertype = bytes
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65
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66 ### encodings module API
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67
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68 def getregentry():
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69 return codecs.CodecInfo(
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70 name="bz2",
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71 encode=bz2_encode,
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72 decode=bz2_decode,
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73 incrementalencoder=IncrementalEncoder,
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74 incrementaldecoder=IncrementalDecoder,
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75 streamwriter=StreamWriter,
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76 streamreader=StreamReader,
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77 _is_text_encoding=False,
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78 )
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