PHP’s include_once() Is Insanely Expensive

I’ve always heard the include_once() and require_once() functions were computationally expensive in PHP, but I never knew how much. I tested the following out on my i7 2010 MacBook Pro using PHP 5.3.4 as shipped by Apple.

This first test uses include_once() to keep track of how often a file is included:

$includes = Array();
$file = ‘benchmarkinclude’;
 
for($i=0; $i < 1000000; $i++){
    include_once($file.‘.php’);
}

Took: 10.020140171051 sec

This second example uses include() and uses in_array() to keep track of if I loaded the include:

$includes = Array();
$file = ‘benchmarkinclude’;
 
for($i=0; $i < 1000000; $i++){
    if(!in_array($file, $includes)){
        include($file . ‘.php’);
        $includes[] = $file;
    }
}

Took: 0.27652382850647 sec

For both, the include had the following computation:

$x = 1 + 1;

Lesson learned: Avoid using _once if you can avoid it.

Update: That means something like this will theoretically be faster:

$rja_includes = Array();
function rja_include_once($file){
    global $rja_includes;
    if(!in_array($file, $rja_includes)){
        include($file);
        $rja_includes[] = $file;
    }
}

Benchmarking And Testing Browsers

When people talk about open source they often talk about the products, not the process. That’s not really a bad thing (it is after all about the product), but it overlooks some really interesting things sometimes. For example open source tools used in open development.

A few months ago Jesse Ruderman introduced jsfunfuzz, which is a tool for fuzz testing the js engine in Firefox. It turned up 280 bugs (many already fixed). Because the tool itself is not horded behind a firewall it’s also helped identify several Safari and Opera bugs. It’s a pretty cool way to find some bugs.

The WebKit team has now released SunSpider a javascript benchmarking tool. Something tells me this will lead to some performance improvements in everyone’s engine. How much will be done for Firefox 3.0 is a little questionable considering beta 2 is nearing release, though you never know. There’s been some nice work on removing allocations recently. So just because it’s beta, you can’t always assume fixes will be minor in scope.

Another test that many are familiar with is Acid 2 which essentially is checking CSS support among browsers. Ironically this one too was released when Gecko is somewhat late in the development cycle.

Efforts like this really help web development by allowing browser developers to have a baseline to compare their strengths and weaknesses. Having a little healthy competition as motivation can be pretty helpful too 😉 .