include/require performance

[TomB]

Profiling my scripts, the biggest drain on performance is the autoloader, specifically the require/include line.

A current site includes 38 files.

I did a quick test using include/require/require once/include once. Profiling just the autoload function and changing only the include/require line here's what I got just as a very basic test.

require_once	124.75ms
require	116.64ms
include_once	120.56ms
include	119.24ms

All very close. Nothing really in it. However, 38 calls to include/require are using 70% of my script's CPU time so it's a hefty chunk of resources and easily the most resource intensive function I have.

Now that still seemed a lot to me but perhaps it just a file I/O bottleneck. As a basic test, I tried:

eval('?>' . file_get_contents($file)); 

instead of

require $file; 

The result... 24.29ms roughly five times faster. This is rather astonishing. obviously eval is bad™ but this proves that include/require are doing a hell of a lot more than simply loading the file. By using eval(file_get_contents()) I've improved my entire script performance by almost 100%.

Any idea why include should be so comparatively slow?

edit: the files being included are doing no real processing on include, they are all just class definitions.

[Mandes]

What version you running there Tom

[TomB]

5.3. However, I'm now wondering whether the profiler itself has something to do with it. I'm using Zend Studio 9 to profile the code. I wonder if the profiler has to modify the include function in some manner.

[John_Betong]

@TomB

Have you tried using Pingdom.com to check the speed of your site? I find that the PHP optimisation makes very little difference and the biggest time gobbler is the waiting for the server to respond.