2013/4/11 Serhiy Storchaka <storch...@gmail.com>: > On 09.04.13 23:29, victor.stinner wrote: >> >> http://hg.python.org/cpython/rev/53879d380313 >> changeset: 83216:53879d380313 >> parent: 83214:b7f2d28260b4 >> user: Victor Stinner <victor.stin...@gmail.com> >> date: Tue Apr 09 21:53:09 2013 +0200 >> summary: >> Add fast-path in PyUnicode_DecodeCharmap() for pure 8 bit encodings: >> cp037, cp500 and iso8859_1 codecs > > I deliberately specialized only most typical case in order to reduce > maintaining cost. Further optimization of two not the most popular encodings > probably not worth additional 25 lines of code.
I did the commit while I was trying to avoid usage of PyUnicode_READ_CHAR() and PyUnicode_READ() in unicodeobject.c (slow macros). I was surprised that PyUnicode_DecodeCharmap() has a fast path for Py_UCS2 mapping but not Py_UCS1 mapping. After implementing the fast-path, I realized that only a very few codecs use it. So what do you suggest? Revert the commit to restore the following "hack" (to only have one fast-path)? '\ufffe' ## Widen to UCS2 for optimization The Py_UCS1 fast-path has a small advantage: decoding cannot fail (no need to call an error handler). Victor _______________________________________________ Python-Dev mailing list Python-Dev@python.org http://mail.python.org/mailman/listinfo/python-dev Unsubscribe: http://mail.python.org/mailman/options/python-dev/archive%40mail-archive.com
