1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
|
"""Python 'zlib_codec' Codec - zlib compression encoding.
This codec de/encodes from bytes to bytes and is therefore usable with
bytes.transform() and bytes.untransform().
Written by Marc-Andre Lemburg (mal@lemburg.com).
"""
import codecs
import zlib # this codec needs the optional zlib module !
### Codec APIs
def zlib_encode(input, errors='strict'):
assert errors == 'strict'
return (zlib.compress(input), len(input))
def zlib_decode(input, errors='strict'):
assert errors == 'strict'
return (zlib.decompress(input), len(input))
class Codec(codecs.Codec):
def encode(self, input, errors='strict'):
return zlib_encode(input, errors)
def decode(self, input, errors='strict'):
return zlib_decode(input, errors)
class IncrementalEncoder(codecs.IncrementalEncoder):
def __init__(self, errors='strict'):
assert errors == 'strict'
self.errors = errors
self.compressobj = zlib.compressobj()
def encode(self, input, final=False):
if final:
c = self.compressobj.compress(input)
return c + self.compressobj.flush()
else:
return self.compressobj.compress(input)
def reset(self):
self.compressobj = zlib.compressobj()
class IncrementalDecoder(codecs.IncrementalDecoder):
def __init__(self, errors='strict'):
assert errors == 'strict'
self.errors = errors
self.decompressobj = zlib.decompressobj()
def decode(self, input, final=False):
if final:
c = self.decompressobj.decompress(input)
return c + self.decompressobj.flush()
else:
return self.decompressobj.decompress(input)
def reset(self):
self.decompressobj = zlib.decompressobj()
class StreamWriter(Codec, codecs.StreamWriter):
charbuffertype = bytes
class StreamReader(Codec, codecs.StreamReader):
charbuffertype = bytes
### encodings module API
def getregentry():
return codecs.CodecInfo(
name='zlib',
encode=zlib_encode,
decode=zlib_decode,
incrementalencoder=IncrementalEncoder,
incrementaldecoder=IncrementalDecoder,
streamreader=StreamReader,
streamwriter=StreamWriter,
_is_text_encoding=False,
)
|
