Test scripts for comparing the performance of declaring and instantiating classes dynamically in PHP using eval versus including from files.

generate-class-code.sh

#!/bin/bash
mkdir $1 || exit

c=0;
while [ $c -lt $1 ]; do
	cat <<EOF >"$1/Foo_$c.php"
<?php
Class Foo_$c
{
	function __construct() {
		return true;
	}
}
?>
EOF
	c=$(($c + 1))
done

time-eval.php

<?php
// Set memory limit to unlimited
ini_set('memory_limit', '-1');

$t = $argv[1];
$start = microtime(true);

// Run the loop
for ($i = 0; $i < $t; $i++) {

	// Generate class code for test. Note that there is a significant difference between having
	// the construct with the return statement than without. We're testing with a return to
	// simulate "some kind of processing" happening in the class instantiation.
	$code = <<<EOF
	Class Foo_$i
	{
		function __construct() {
			return true;
		}
	}
EOF;

	// This eval instantiates the class
	eval($code);

	// This eval adds some processing time to assign an instantiated class to a variable
	$foo = eval("return new Foo_$i;");
}

$end = microtime(true);

echo "Iterations: " . $t . "\n";
echo "Time: " . round($end - $start, 3) . "s\n";
echo "Memory (real): " . round(memory_get_usage(true) / 1024 / 1024, 2) . "MB\n";
?>

time-include.php

<?php
// Set memory limit to unlimited
ini_set('memory_limit', '-1');

$t = $argv[1];
$start = microtime(true);

// Run the loop
for ($i = 0; $i < $t; $i++) {

	// Include the class code
	require_once "./" . $t . "/Foo_" . $i . ".php";

	// This eval adds some processing time to assign an instantiated class to a variable
	$foo = eval("return new Foo_$i;");
}

$end = microtime(true);

echo "Iterations: " . $t . "\n";
echo "Time: " . round($end - $start, 3) . "s\n";
echo "Memory (real): " . round(memory_get_usage(true) / 1024 / 1024, 2) . "MB\n";
?>

Sample results:

Declaring and instantiating 10,000 classes using eval:

$ php ./time-eval.php 10000
Iterations: 10000
Time: 0.262s
Memory (real): 22MB

Declaring 10,000 classes using require_once and instantiating them using eval (without APC):

$ php ./time-include.php 10000
Iterations: 10000
Time: 1.198s
Memory (real): 26.25MB

Declaring 10,000 classes using require_once and instantiating them using eval (with APC):

$ php ./time-include.php 10000
Iterations: 10000
Time: 1.474s
Memory (real): 26.25MB
$