Bug #72640 [NEW]: Regexp with possessive/atomic grouping 25x slower compared to 5.6.x
From: arjen at parse dot nl
Operating system: Linux
PHP version: 7.0.9
Package: PCRE related
Bug Type: Bug
Bug description:Regexp with possessive/atomic grouping 25x slower compared to 5.6.x
Description:
------------
After reading
http://stackstatus.net/post/147710624694/outage-postmortem-july-20-2016
we checked our own implementation. We did not use possessive or atomic
grouping in our trim regexps, so one trim call with 20000 whitespace
char and a following non-whitespace char took 6 seconds. After updating
the regexp this dropped to 2 seconds. Better but still not safe
enough..
So we checked the performance in different php versions on 3v4l.org and
5.6 appeared 25x faster: https://3v4l.org/SPEXB/perf#tabs
Avg 0.066 for 5.6.x compared to 1.670 for 7.0.x
Test script:
---------------
<?php
preg_replace('~(?>[\pZ\pC]+)$~u', '', str_repeat("\u{2029}", 20000)
.
'x');
Expected result:
----------------
Run-time comparable to 5.6.x
Actual result:
--------------
25x slowdown.
--
Edit bug report at https://bugs.php.net/bug.php?id=72640&edit=1
--
Try a snapshot (PHP 5.4): https://bugs.php.net/fix.php?id=72640&r=trysnapshot54
Try a snapshot (PHP 5.5): https://bugs.php.net/fix.php?id=72640&r=trysnapshot55
Try a snapshot (trunk): https://bugs.php.net/fix.php?id=72640&r=trysnapshottrunk
Fixed in SVN: https://bugs.php.net/fix.php?id=72640&r=fixed
Fixed in release: https://bugs.php.net/fix.php?id=72640&r=alreadyfixed
Need backtrace: https://bugs.php.net/fix.php?id=72640&r=needtrace
Need Reproduce Script: https://bugs.php.net/fix.php?id=72640&r=needscript
Try newer version: https://bugs.php.net/fix.php?id=72640&r=oldversion
Not developer issue: https://bugs.php.net/fix.php?id=72640&r=support
Expected behavior: https://bugs.php.net/fix.php?id=72640&r=notwrong
Not enough info: https://bugs.php.net/fix.php?id=72640&r=notenoughinfo
Submitted twice: https://bugs.php.net/fix.php?id=72640&r=submittedtwice
register_globals: https://bugs.php.net/fix.php?id=72640&r=globals
PHP 4 support discontinued: https://bugs.php.net/fix.php?id=72640&r=php4
Daylight Savings: https://bugs.php.net/fix.php?id=72640&r=dst
IIS Stability: https://bugs.php.net/fix.php?id=72640&r=isapi
Install GNU Sed: https://bugs.php.net/fix.php?id=72640&r=gnused
Floating point limitations: https://bugs.php.net/fix.php?id=72640&r=float
No Zend Extensions: https://bugs.php.net/fix.php?id=72640&r=nozend
MySQL Configuration Error: https://bugs.php.net/fix.php?id=72640&r=mysqlcfg
Thread (9 messages)
- arjen at parse dot nl