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author | Sviatoslav Sydorenko <wk@sydorenko.org.ua> | 2020-11-15 01:21:55 +0100 |
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committer | Sviatoslav Sydorenko <wk@sydorenko.org.ua> | 2020-11-15 02:58:16 +0100 |
commit | b4eb20e5803ccf11d5a84044ada8ebc6dc411ab1 (patch) | |
tree | 586686824ddbd5d52f3b22546cb414659f376ca1 | |
parent | 05ee11a96940817e471cce3675ac1fb1810f11e8 (diff) | |
download | cherrypy-git-bugfixes/1849-gzip-compression-header-cpython-bug39389.tar.gz |
Fix compression level in meta header in gzip toolbugfixes/1849-gzip-compression-header-cpython-bug39389
* https://bugs.python.org/issue39389
* https://github.com/python/cpython/pull/18077
* https://github.com/python/cpython/pull/18100
* https://github.com/python/cpython/pull/18101
Fixes #1849
-rw-r--r-- | cherrypy/lib/encoding.py | 24 | ||||
-rw-r--r-- | cherrypy/test/test_tools.py | 17 |
2 files changed, 39 insertions, 2 deletions
diff --git a/cherrypy/lib/encoding.py b/cherrypy/lib/encoding.py index 54a7a8a8..c2c478a5 100644 --- a/cherrypy/lib/encoding.py +++ b/cherrypy/lib/encoding.py @@ -9,6 +9,10 @@ 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. @@ -285,13 +289,29 @@ 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'') diff --git a/cherrypy/test/test_tools.py b/cherrypy/test/test_tools.py index 3a0fd389..be8a4798 100644 --- a/cherrypy/test/test_tools.py +++ b/cherrypy/test/test_tools.py @@ -15,6 +15,16 @@ from cherrypy._cpcompat import ntou from cherrypy.test import helper, _test_decorators +*PY_VER_MINOR, _ = PY_VER_PATCH = sys.version_info[:3] +# Refs: +# bugs.python.org/issue39389 +# docs.python.org/3.7/whatsnew/changelog.html#python-3-7-7-release-candidate-1 +# docs.python.org/3.8/whatsnew/changelog.html#python-3-8-2-release-candidate-1 +HAS_GZIP_COMPRESSION_HEADER_FIXED = PY_VER_PATCH >= (3, 8, 2) or ( + PY_VER_MINOR == (3, 7) and PY_VER_PATCH >= (3, 7, 7) +) + + timeout = 0.2 europoundUnicode = ntou('\x80\xa3') @@ -357,6 +367,13 @@ class ToolTests(helper.CPWebCase): ('Accept-Charset', 'ISO-8859-1,utf-8;q=0.7,*;q=0.7')]) self.assertInBody(zbuf.getvalue()[:3]) + if not HAS_GZIP_COMPRESSION_HEADER_FIXED: + # NOTE: CherryPy adopts a fix from the CPython bug 39389 + # NOTE: introducing a variable compression XFL flag that + # NOTE: was hardcoded to "best compression" before. And so + # NOTE: we can only test it on CPython versions that also + # NOTE: implement this fix. + return zbuf = io.BytesIO() zfile = gzip.GzipFile(mode='wb', fileobj=zbuf, compresslevel=6) zfile.write(expectedResult) |