ref: d68f4adeba6ef0db7590cf7c4e1518f4d4bdedff
dir: /sys/lib/python/encodings/bz2_codec.py/
""" Python 'bz2_codec' Codec - bz2 compression encoding
Unlike most of the other codecs which target Unicode, this codec
will return Python string objects for both encode and decode.
Adapted by Raymond Hettinger from zlib_codec.py which was written
by Marc-Andre Lemburg (mal@lemburg.com).
"""
import codecs
import bz2 # this codec needs the optional bz2 module !
### Codec APIs
def bz2_encode(input,errors='strict'):
""" Encodes the object input and returns a tuple (output
object, length consumed).
errors defines the error handling to apply. It defaults to
'strict' handling which is the only currently supported
error handling for this codec.
"""
assert errors == 'strict'
output = bz2.compress(input)
return (output, len(input))
def bz2_decode(input,errors='strict'):
""" Decodes the object input and returns a tuple (output
object, length consumed).
input must be an object which provides the bf_getreadbuf
buffer slot. Python strings, buffer objects and memory
mapped files are examples of objects providing this slot.
errors defines the error handling to apply. It defaults to
'strict' handling which is the only currently supported
error handling for this codec.
"""
assert errors == 'strict'
output = bz2.decompress(input)
return (output, len(input))
class Codec(codecs.Codec):
def encode(self, input, errors='strict'):
return bz2_encode(input, errors)
def decode(self, input, errors='strict'):
return bz2_decode(input, errors)
class IncrementalEncoder(codecs.IncrementalEncoder):
def __init__(self, errors='strict'):
assert errors == 'strict'
self.errors = errors
self.compressobj = bz2.BZ2Compressor()
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 = bz2.BZ2Compressor()
class IncrementalDecoder(codecs.IncrementalDecoder):
def __init__(self, errors='strict'):
assert errors == 'strict'
self.errors = errors
self.decompressobj = bz2.BZ2Decompressor()
def decode(self, input, final=False):
try:
return self.decompressobj.decompress(input)
except EOFError:
return ''
def reset(self):
self.decompressobj = bz2.BZ2Decompressor()
class StreamWriter(Codec,codecs.StreamWriter):
pass
class StreamReader(Codec,codecs.StreamReader):
pass
### encodings module API
def getregentry():
return codecs.CodecInfo(
name="bz2",
encode=bz2_encode,
decode=bz2_decode,
incrementalencoder=IncrementalEncoder,
incrementaldecoder=IncrementalDecoder,
streamwriter=StreamWriter,
streamreader=StreamReader,
)