ID: 45265 Comment by: foruns at dan dot mus dot br Reported By: marc at phpmyadmin dot net Status: Assigned Bug Type: Performance problem Operating System: win32 only PHP Version: 5.2CVS-2008-08-10 Assigned To: pajoye New Comment:
I'm running PHP 5.2.6 in a G4 iBook PPC and I'm experiencing extremely low performance using that function. I intended to use stripos() inside a loop to retrieve the positions of multiple DIV elements in a HTML page, increasing the offset value accordingly. But, on a 64kb document, it would take from 0.4sec to 2.5sec to find each "<div" string. Strpos() would take as little as 0.004sec on the same document. Daniel Previous Comments: ------------------------------------------------------------------------ [2008-08-11 00:34:09] ni...@php.net And according to http://msdn.microsoft.com/en-us/library/8h19t214(VS.80).aspx _tolower's Windows implentation isn't ANSI. ------------------------------------------------------------------------ [2008-08-11 00:15:45] ni...@php.net Nice work Pierre but according to MSDN and yourself, _tolower's Windows implementation is clearly faster than tolower but has undefined results if the character is not ASCII... And we can't rely on that... can we? According to libc, tolower checks the locale too... And _lower on libc is quite different than Windows's since the _tolower() function is identical to tolower() except that c must be an upper-case letter. So... ------------------------------------------------------------------------ [2008-08-10 23:41:53] paj...@php.net The problem is that the Windows API does check for the locale while processing the string (isupper, islower used by tolower or toupper). Using _tolower/_toupper only speed up the functions using it (as fast or faster than linux). But it does not work for non ASCII input. I have to check is libc does check for locale as well, if not, I will happily use _tolower on windows too. That being said, it may be used too in zend then. tolower is used *many* times there. ------------------------------------------------------------------------ [2008-08-10 17:01:44] ni...@php.net It seems it's a php_strtolower() issue because we have the same problem by replacing stripos to strtolower... The problem occurs on Windows also with strtolower()... 71 seconds on Windows, 25s on linux... Reproduce code: $a = str_repeat('x', 100000); for ($i = 0; $i < 10000; $i++) { $b = strtolower($a); } ------------------------------------------------------------------------ [2008-06-13 17:44:20] marc at phpmyadmin dot net Description: ------------ stripos() is very slow on Windows, about ten times slower than on Linux. Reproduce code: --------------- $a = str_repeat('x', 100000); for ($i = 0; $i < 10000; $i++) { $b = stripos($a, 'y'); } Expected result: ---------------- On Linux it takes about 3 secondes. Actual result: -------------- On Windows: 30 seconds ------------------------------------------------------------------------ -- Edit this bug report at http://bugs.php.net/?id=45265&edit=1
