Bug #53416 [NEW]: iterate over array of complex objects slower than array of simple objects
From:
Operating system: Ubuntu Server 10
PHP version: 5.3.3
Package: Performance problem
Bug Type: Bug
Bug description:iterate over array of complex objects slower than array of simple objects
Description:
------------
I do not understand if is an error or not, but iterating over arrays with
complex objects is slower than iterate over arrays made with more simple
objects.
In some case (but i can't reproduce it), iterate over arrays with 100
elements is 100x slower than iterate other array made of 100 simpler
objects.
(sorry for my English)
Test script:
---------------
<?php
// create some arrays
// integer array (1000 items)
$vals = range(0,1000);
// simple object array (1000 items)
$obj = array_map(function($v){
$o = new stdClass();
$o->v = $v;
return $o;
}, $vals);
// more complex object array (1000 items)
$objs = array_map(function($v)use(&$obj){
$o = new stdClass();
$o->res = array();
for ($i = 0; $i<500; $i++){
$o->res[$i] = $obj[$i];
}
for (true; $i<1000; $i++){
$o->{'res'.$i} = $obj[$i];
}
return $o;
}, $vals);
// TESTS
// 1. loop over integer array
// 1000000 iterations
$t = microtime(1);
foreach ($vals as $o1){
foreach ($vals as $o2){
}
}
echo microtime(1)-$t."\n";
// 2. loop over simple object array
// 1000000 iterations
// 15% slower than loop n.1
$t = microtime(1);
foreach ($obj as $o1){
foreach ($obj as $o2){
}
}
echo microtime(1)-$t."\n";
// 3. loop over complex object array
// 1000000 iterations
// 50% slower than loop n.1
$t = microtime(1);
foreach ($objs as $o1){
foreach ($objs as $o2){
}
}
echo microtime(1)-$t."\n";
Expected result:
----------------
all loop should take the same amount of time. (at most with slight
differences)
Actual result:
--------------
loop n.3 is 50% slower than loop 1
loop n.3 is 30% slower than loop 2
in some case iterate over complex array can be 100x slower
--
Edit bug report at http://bugs.php.net/bug.php?id=53416&edit=1
--
Try a snapshot (PHP 5.2): http://bugs.php.net/fix.php?id=53416&r=trysnapshot52
Try a snapshot (PHP 5.3): http://bugs.php.net/fix.php?id=53416&r=trysnapshot53
Try a snapshot (trunk): http://bugs.php.net/fix.php?id=53416&r=trysnapshottrunk
Fixed in SVN: http://bugs.php.net/fix.php?id=53416&r=fixed
Fixed in SVN and need be documented: http://bugs.php.net/fix.php?id=53416&r=needdocs
Fixed in release: http://bugs.php.net/fix.php?id=53416&r=alreadyfixed
Need backtrace: http://bugs.php.net/fix.php?id=53416&r=needtrace
Need Reproduce Script: http://bugs.php.net/fix.php?id=53416&r=needscript
Try newer version: http://bugs.php.net/fix.php?id=53416&r=oldversion
Not developer issue: http://bugs.php.net/fix.php?id=53416&r=support
Expected behavior: http://bugs.php.net/fix.php?id=53416&r=notwrong
Not enough info: http://bugs.php.net/fix.php?id=53416&r=notenoughinfo
Submitted twice: http://bugs.php.net/fix.php?id=53416&r=submittedtwice
register_globals: http://bugs.php.net/fix.php?id=53416&r=globals
PHP 4 support discontinued: http://bugs.php.net/fix.php?id=53416&r=php4
Daylight Savings: http://bugs.php.net/fix.php?id=53416&r=dst
IIS Stability: http://bugs.php.net/fix.php?id=53416&r=isapi
Install GNU Sed: http://bugs.php.net/fix.php?id=53416&r=gnused
Floating point limitations: http://bugs.php.net/fix.php?id=53416&r=float
No Zend Extensions: http://bugs.php.net/fix.php?id=53416&r=nozend
MySQL Configuration Error: http://bugs.php.net/fix.php?id=53416&r=mysqlcfg
Thread (3 messages)
- goetas at lignano dot it