aboutsummaryrefslogtreecommitdiffstats
path: root/libmproxy/encoding.py
blob: f280ed9fcbb70de8b1130f71858b0965bd7ded89 (plain)
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
"""
    Utility functions for decoding response bodies.
"""
import cStringIO
import gzip, zlib

__ALL__ = ["ENCODINGS"]

ENCODINGS = set(["identity", "gzip", "deflate"])

def decode(encoding, content):
    encoding_map = {
        "identity": decode_identity,
        "gzip": decode_gzip,
        "deflate": decode_deflate,
    }

    return encoding_map.get(encoding, decode_identity)(content)

def decode_identity(content):
    """
        Returns content unchanged. Identity is the default value of
        Accept-Encoding headers.
    """
    return content

def decode_gzip(content):
    gfile = gzip.GzipFile(fileobj=cStringIO.StringIO(content))
    return gfile.read()

def decode_deflate(content):
    """
        Returns decompress data for DEFLATE. Some servers may respond with
        compressed data without a zlib header or checksum. An undocumented
        feature of zlib permits the lenient decompression of data missing both
        values.

        http://bugs.python.org/issue5784
    """
    try:
        return zlib.decompress(content)
    except zlib.error:
        return zlib.decompress(content, -15)