ID: 47643 Comment by: emiel dot bruijntjes at copernica dot com Reported By: viper7 at viper-7 dot com Status: Assigned Bug Type: Performance problem Operating System: * PHP Version: 5.*, 6CVS (2009-04-13) Assigned To: felipe New Comment:
This bug is now open for 10 months. Are you still working on this? Previous Comments: ------------------------------------------------------------------------ [2009-07-09 20:38:20] j...@php.net As Dmitry's noted, this is side-effect your fix caused. ------------------------------------------------------------------------ [2009-07-01 15:32:01] dmi...@php.net The problems occurs because of "bad" patch for bug #42838. The diff algorithm sorts arrays using qsort and then assumes that they are sorted correctly. But in case of user compaison function it can't be guaranteed. Thus in ext/standard/tests/array/bug42838.phpt key_compare_func() can't sort array correctly because expressions (0 < 'a') and (0 > 'a') both false ('a' is interpreted as a number 0). It should be fixed in some way ------------------------------------------------------------------------ [2009-06-30 15:22:24] der...@php.net Dmitry, could you have a look? I have no idea why this occurs. ------------------------------------------------------------------------ [2009-06-30 15:19:43] viper7 at viper-7 dot com I've tracked down the change that broke things, this is it. but the exact reason is beyond me heh. Hopefully this helps. http://cvs.php.net/viewvc.cgi/php-src/ext/standard/array.c?r1=1.308.2.21.2.51&r2=1.308.2.21.2.52&pathrev=PHP_5_2 ------------------------------------------------------------------------ [2009-03-24 21:19:01] cisa at cisa85 dot de Like I described [1] I use this function to get the performance I need: function array_diff_fast($data1, $data2) { $data1 = array_flip($data1); $data2 = array_flip($data2); foreach($data2 as $hash => $key) { if (isset($data1[$hash])) unset($data1[$hash]); } return array_flip($data1); } Thanks to Viper for his help. [1] http://nohostname.de/blog/2009/03/24/bug-gefunden-array_diff-in-php-526-unglaublich-langsam/ ------------------------------------------------------------------------ The remainder of the comments for this report are too long. To view the rest of the comments, please view the bug report online at http://bugs.php.net/47643 -- Edit this bug report at http://bugs.php.net/?id=47643&edit=1