Created on 2012-05-21 22:19 by serhiy.storchaka, last changed 2012-06-16 20:54 by pitrou. This issue is now closed.
| Files | ||||
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| File name | Uploaded | Description | Edit | |
| decode_charmap.patch | serhiy.storchaka, 2012-05-21 22:19 | review | ||
| charmapdecodebench.py | serhiy.storchaka, 2012-05-21 22:20 | Benchmark script | ||
| bench-diff.py | serhiy.storchaka, 2012-05-21 22:21 | Benchmark results comparator | ||
| Messages (3) | |||
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| msg161301 - (view) | Author: Serhiy Storchaka (serhiy.storchaka) *  |
Date: 2012-05-21 22:19 | |
Charmap decoders are not as important as UTF decoders, but are still widely used. In Python 3.3 with PEP 393 they slowed down 4x. The proposed patch restores the performance. Optimized only the most common case, when the decoder is specified by the UCS2 table with length >= 256. Map-based decoders translated to table-based. UCS1 tables widened to UCS2 by adding 257th fake characters. Benchmark results: 3.2 3.3(vanilla) 3.3(patched) cp1251 'A'*10000 111 (+10%) 31 (+294%) 122 cp1251 '\xa0'*10000 111 (+8%) 29 (+314%) 120 cp1251 '\u0402'*10000 111 (+6%) 25 (+372%) 118 |
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| msg162989 - (view) | Author: Roundup Robot (python-dev) | Date: 2012-06-16 20:54 | |
New changeset 8f3a5308f50b by Antoine Pitrou in branch 'default': Issue #14874: Restore charmap decoding speed to pre-PEP 393 levels. http://hg.python.org/cpython/rev/8f3a5308f50b |
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| msg162990 - (view) | Author: Antoine Pitrou (pitrou) * |
Date: 2012-06-16 20:54 | |
Thank you for the patch! Now pushed to 3.3. |
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| History | |||
|---|---|---|---|
| Date | User | Action | Args |
| 2012-06-16 20:54:32 | pitrou | set | status: open -> closed resolution: fixed messages: + msg162990 stage: patch review -> resolved |
| 2012-06-16 20:54:06 | python-dev | set | nosy:
+ python-dev messages: + msg162989 |
| 2012-06-16 16:44:22 | pitrou | set | nosy:
+ loewis |
| 2012-06-15 17:51:10 | pitrou | set | stage: patch review |
| 2012-05-21 22:21:38 | serhiy.storchaka | set | files: + bench-diff.py |
| 2012-05-21 22:20:13 | serhiy.storchaka | set | files: + charmapdecodebench.py |
| 2012-05-21 22:19:29 | serhiy.storchaka | create | |