CPHPCacheFiles::_randomizeFile

static function _randomizeFile($fileName)
{
	for($i = 0; $i < 99; $i++) //try to get new directory name no more than ten times
	{
		$suffix = rand(0, 999999);
		if(!file_exists($_SERVER["DOCUMENT_ROOT"].$fileName.$suffix))
			return $fileName.$suffix;
	}
	return "";
}