Bug #18829 [Com]: array_pop, array_shift, array_push... functions very slow with large arrays

Edit report at https://bugs.php.net/bug.php?id=18829&edit=1 ID: 18829 Comment by: tszming at gmail dot com Reported by: jean-charles dot rogez at devoteam dot com Summary: array_pop, array_shift, array_push... functions very slow with large arrays Status: Wont fix Type: Bug Package: Arrays related Operating System: Linux RedHat 7.1 PHP Version: 4.2.2 Assigned To: rodif_bl Block user comment: N Private report: N New Comment: Maybe some optimization can be done if we know a variable is an array but not a hash? I believe JavaScript also share similar issue and they got optimized finally, e.g: https://bugzilla.mozilla.org/show_bug.cgi?id=394448 Previous Comments: ------------------------------------------------------------------------ [2002-10-28 14:05:54] sterling@php.net PHP is not perl, since arrays are bastards (the unwed child of a hash and array) there is really not a more efficient way to handle this, without breaking things badly... ------------------------------------------------------------------------ [2002-08-13 20:45:48] kalowsky@php.net Assigning to Brad, as he seems to be working on it... a bit. ------------------------------------------------------------------------ [2002-08-13 04:11:32] jean-charles dot rogez at devoteam dot com In perl : @a = (1, 2, 3); shift(@a); print "$a[0], $a[1]"; Result : 2, 3 This is correct. I don't know how the shift function is implemented in perl, but i think arrays are not reindexed like in PHP, else it shouldn't be so fast. ------------------------------------------------------------------------ [2002-08-12 09:18:55] rodif_bl@php.net The problem wasn't just array_shift it was array_shift and array_pop. array_shift is whats causing the slowness now but way its implemented now I really don't think it can get much faster. Basically when you shift of the top of the array it needs to re-index the entire array meaning if you have 10,000 records it needs to loop thru all 10,000 changing the index. If the function didn't need to do this it wouldn't take nearly as long. Does it work this way in perl or python. $a = array(1,2); array_shift($a); echo $a[0]; ------------------------------------------------------------------------ [2002-08-12 04:25:03] jean-charles dot rogez at devoteam dot com Same results than you. The script takes approximately 4 minutes on my P4 1.5Ghz with the latest CVS (before it was 87m...). After correction of the array_shift function, PHP should be in the same time than Perl or Python. ------------------------------------------------------------------------ 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 https://bugs.php.net/bug.php?id=18829 -- Edit this bug report at https://bugs.php.net/bug.php?id=18829&edit=1