New submission from STINNER Victor: The "us-ascii" encoding is an alias to the Python ASCII encoding. PyUnicode_AsEncodedString() and PyUnicode_Decode() functions have a fast-path for the "ascii" string, but not for "us-ascii".
Attached patch uses also the fast-path for "us-ascii". It's a more generic change than the issue #27915. The "us-ascii" name is common in the email and xml.etree modules. Other changes of the patch: * Rewrite _Py_normalize_encoding() as a C implementation of encodings.normalize_encoding(). For example, " utf-8 " is now normalized to "utf_8". So the fast path is now used for more name variants of the same encoding. * Avoid strcpy() when encoding is NULL: call directly the UTF-8 codec * Reorder encodings: UTF-8, ASCII, MBCS, Latin1, UTF-16 * Remove fast-path for UTF-32: seriously, nobody uses this codec. Latin9 is much faster but has no fast-path. ---------- components: Interpreter Core, Unicode files: normalize_encoding.patch keywords: patch messages: 274222 nosy: ezio.melotti, haypo, scop, serhiy.storchaka priority: normal severity: normal status: open title: PyUnicode_AsEncodedString, PyUnicode_Decode: add fast-path for "us-ascii" encoding type: performance versions: Python 3.6 Added file: http://bugs.python.org/file44345/normalize_encoding.patch _______________________________________ Python tracker <rep...@bugs.python.org> <http://bugs.python.org/issue27938> _______________________________________ _______________________________________________ Python-bugs-list mailing list Unsubscribe: https://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
