bench_fstatcache.php

<?php

function bench($name, $fn, array $args = array(), $step = 10000) {
	$times = array();

	while($step--) {
		$s = microtime(true);
		call_user_func_array($fn, $args);
		$e = microtime(true);
		$times[] = $e - $s;
	}

	$total = array_sum($times);
	$average = $total / count($times);
	$max = max($times);
	$min = min($times);

	echo sprintf("%s\t%.4f\t%.4f\t%.4f\t%.4f", $name, $total, $average, $max, $min).PHP_EOL;
}

function call_with_cache($fn)
{
	$fn(__FILE__);
}
function call_nocache($fn)
{
	clearstatcache();
	$fn(__FILE__);
}

$stat_affected_functions = array(
	'stat',
	'lstat',
	'file_exists',
	'is_writable',
	'is_readable',
	'is_executable',
	'is_file',
	'is_dir',
	'is_link',
	'filectime',
	'fileatime',
	'filemtime',
	'fileinode',
	'filegroup',
	'fileowner',
	'filesize',
	'filetype',
	'fileperms'
);

echo "name\ttotal\tavg\tmax\tmin".PHP_EOL;
foreach ($stat_affected_functions as $fn) {
	bench("{$fn}+cache", 'call_with_cache', array($fn));
	bench($fn, 'call_nocache', array($fn));
}