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| author | Sviatoslav Sydorenko <wk@sydorenko.org.ua> | 2020-11-15 02:58:49 +0100 |
|---|---|---|
| committer | Sviatoslav Sydorenko <wk@sydorenko.org.ua> | 2020-11-15 03:32:42 +0100 |
| commit | 3b642b19937eafa8135a59c9bf38cd37f0a57e87 (patch) | |
| tree | 48d774876711c91bf62605b80953a238444499bd /cherrypy/lib/encoding.py | |
| parent | 5c8258371d4a53ef939b7a38d1b1fbaf362e6078 (diff) | |
| download | cherrypy-git-maint/17.x.tar.gz | |
Merge branch 'bugfixes/1849-gzip-compression-header-cpython-bug39389'maint/17.x
This change implements a fix to compression in gzip tool that CPython
applied per https://bugs.python.org/issue39389. It uses proper XFL
value in gzip header per https://tools.ietf.org/html/rfc1952, section
2.3.1.
Refs:
* https://github.com/python/cpython/pull/18077 (CPython 3.9.0+)
* https://github.com/python/cpython/pull/18100 (CPython 3.8.2+)
* https://github.com/python/cpython/pull/18101 (CPython 3.7.7+)
Fixes #1849
(cherry picked from commit 3925ae9dffb3d0b8d7792ccd1fd8fefae6f20089)
Diffstat (limited to 'cherrypy/lib/encoding.py')
| -rw-r--r-- | cherrypy/lib/encoding.py | 24 |
1 files changed, 22 insertions, 2 deletions
diff --git a/cherrypy/lib/encoding.py b/cherrypy/lib/encoding.py index 3d001ca6..4f9495e4 100644 --- a/cherrypy/lib/encoding.py +++ b/cherrypy/lib/encoding.py @@ -11,6 +11,10 @@ from cherrypy.lib import is_closable_iterator from cherrypy.lib import set_vary_header +_COMPRESSION_LEVEL_FAST = 1 +_COMPRESSION_LEVEL_BEST = 9 + + def decode(encoding=None, default_encoding='utf-8'): """Replace or extend the list of charsets used to decode a request entity. @@ -287,13 +291,29 @@ def compress(body, compress_level): """Compress 'body' at the given compress_level.""" import zlib - # See http://www.gzip.org/zlib/rfc-gzip.html + # See https://tools.ietf.org/html/rfc1952 yield b'\x1f\x8b' # ID1 and ID2: gzip marker yield b'\x08' # CM: compression method yield b'\x00' # FLG: none set # MTIME: 4 bytes yield struct.pack('<L', int(time.time()) & int('FFFFFFFF', 16)) - yield b'\x02' # XFL: max compression, slowest algo + + # RFC 1952, section 2.3.1: + # + # XFL (eXtra FLags) + # These flags are available for use by specific compression + # methods. The "deflate" method (CM = 8) sets these flags as + # follows: + # + # XFL = 2 - compressor used maximum compression, + # slowest algorithm + # XFL = 4 - compressor used fastest algorithm + if compress_level == _COMPRESSION_LEVEL_BEST: + yield b'\x02' # XFL: max compression, slowest algo + elif compress_level == _COMPRESSION_LEVEL_FAST: + yield b'\x04' # XFL: min compression, fastest algo + else: + yield b'\x00' # XFL: compression unset/tradeoff yield b'\xff' # OS: unknown crc = zlib.crc32(b'') |