1""" Python 'bz2_codec' Codec - bz2 compression encoding
2
3    Unlike most of the other codecs which target Unicode, this codec
4    will return Python string objects for both encode and decode.
5
6    Adapted by Raymond Hettinger from zlib_codec.py which was written
7    by Marc-Andre Lemburg (mal@lemburg.com).
8
9"""
10import codecs
11import bz2 # this codec needs the optional bz2 module !
12
13### Codec APIs
14
15def bz2_encode(input,errors='strict'):
16
17    """ Encodes the object input and returns a tuple (output
18        object, length consumed).
19
20        errors defines the error handling to apply. It defaults to
21        'strict' handling which is the only currently supported
22        error handling for this codec.
23
24    """
25    assert errors == 'strict'
26    output = bz2.compress(input)
27    return (output, len(input))
28
29def bz2_decode(input,errors='strict'):
30
31    """ Decodes the object input and returns a tuple (output
32        object, length consumed).
33
34        input must be an object which provides the bf_getreadbuf
35        buffer slot. Python strings, buffer objects and memory
36        mapped files are examples of objects providing this slot.
37
38        errors defines the error handling to apply. It defaults to
39        'strict' handling which is the only currently supported
40        error handling for this codec.
41
42    """
43    assert errors == 'strict'
44    output = bz2.decompress(input)
45    return (output, len(input))
46
47class Codec(codecs.Codec):
48
49    def encode(self, input, errors='strict'):
50        return bz2_encode(input, errors)
51    def decode(self, input, errors='strict'):
52        return bz2_decode(input, errors)
53
54class IncrementalEncoder(codecs.IncrementalEncoder):
55    def __init__(self, errors='strict'):
56        assert errors == 'strict'
57        self.errors = errors
58        self.compressobj = bz2.BZ2Compressor()
59
60    def encode(self, input, final=False):
61        if final:
62            c = self.compressobj.compress(input)
63            return c + self.compressobj.flush()
64        else:
65            return self.compressobj.compress(input)
66
67    def reset(self):
68        self.compressobj = bz2.BZ2Compressor()
69
70class IncrementalDecoder(codecs.IncrementalDecoder):
71    def __init__(self, errors='strict'):
72        assert errors == 'strict'
73        self.errors = errors
74        self.decompressobj = bz2.BZ2Decompressor()
75
76    def decode(self, input, final=False):
77        try:
78            return self.decompressobj.decompress(input)
79        except EOFError:
80            return ''
81
82    def reset(self):
83        self.decompressobj = bz2.BZ2Decompressor()
84
85class StreamWriter(Codec,codecs.StreamWriter):
86    pass
87
88class StreamReader(Codec,codecs.StreamReader):
89    pass
90
91### encodings module API
92
93def getregentry():
94    return codecs.CodecInfo(
95        name="bz2",
96        encode=bz2_encode,
97        decode=bz2_decode,
98        incrementalencoder=IncrementalEncoder,
99        incrementaldecoder=IncrementalDecoder,
100        streamwriter=StreamWriter,
101        streamreader=StreamReader,
102        _is_text_encoding=False,
103    )
104