Added codec for bz2 compression.

Lib/encodings/bz2_codec.py

@@ -0,0 +1,64 @@
+""" 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 bz2_codec 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 StreamWriter(Codec,codecs.StreamWriter):
+    pass
+
+class StreamReader(Codec,codecs.StreamReader):
+    pass
+
+### encodings module API
+
+def getregentry():
+
+    return (bz2_encode,bz2_decode,StreamReader,StreamWriter)