| Marc-André Lemburg | 2d92041 | 2001-05-15 12:00:02 +0000 | [diff] [blame^] | 1 | """ Python 'zlib_codec' Codec - zlib 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 | Written by Marc-Andre Lemburg (mal@lemburg.com). |
| 7 | |
| 8 | """ |
| 9 | import codecs |
| 10 | import zlib # this codec needs the optional zlib module ! |
| 11 | |
| 12 | ### Codec APIs |
| 13 | |
| 14 | def zlib_encode(input,errors='strict'): |
| 15 | |
| 16 | """ Encodes the object input and returns a tuple (output |
| 17 | object, length consumed). |
| 18 | |
| 19 | errors defines the error handling to apply. It defaults to |
| 20 | 'strict' handling which is the only currently supported |
| 21 | error handling for this codec. |
| 22 | |
| 23 | """ |
| 24 | assert errors == 'strict' |
| 25 | output = zlib.compress(input) |
| 26 | return (output, len(input)) |
| 27 | |
| 28 | def zlib_decode(input,errors='strict'): |
| 29 | |
| 30 | """ Decodes the object input and returns a tuple (output |
| 31 | object, length consumed). |
| 32 | |
| 33 | input must be an object which provides the bf_getreadbuf |
| 34 | buffer slot. Python strings, buffer objects and memory |
| 35 | mapped files are examples of objects providing this slot. |
| 36 | |
| 37 | errors defines the error handling to apply. It defaults to |
| 38 | 'strict' handling which is the only currently supported |
| 39 | error handling for this codec. |
| 40 | |
| 41 | """ |
| 42 | assert errors == 'strict' |
| 43 | output = zlib.decompress(input) |
| 44 | return (output, len(input)) |
| 45 | |
| 46 | class Codec(codecs.Codec): |
| 47 | |
| 48 | encode = zlib_encode |
| 49 | decode = zlib_decode |
| 50 | |
| 51 | class StreamWriter(Codec,codecs.StreamWriter): |
| 52 | pass |
| 53 | |
| 54 | class StreamReader(Codec,codecs.StreamReader): |
| 55 | pass |
| 56 | |
| 57 | ### encodings module API |
| 58 | |
| 59 | def getregentry(): |
| 60 | |
| 61 | return (zlib_encode,zlib_decode,StreamReader,StreamWriter) |