wp_is_mobile performance test

wp_is_mobile_test.php

<?php

function wp_is_mobile() {
	/*static $is_mobile;
	if ( isset($is_mobile) )
		return $is_mobile;/* removed for performance testing purposes */
	if ( empty($_SERVER['HTTP_USER_AGENT']) ) {
		$is_mobile = false;
	} elseif ( strpos($_SERVER['HTTP_USER_AGENT'], 'Mobile') !== false // many mobile devices (all iPhone, iPad, etc.)
		|| strpos($_SERVER['HTTP_USER_AGENT'], 'Android') !== false
		|| strpos($_SERVER['HTTP_USER_AGENT'], 'Silk/') !== false
		|| strpos($_SERVER['HTTP_USER_AGENT'], 'Kindle') !== false
		|| strpos($_SERVER['HTTP_USER_AGENT'], 'BlackBerry') !== false
		|| strpos($_SERVER['HTTP_USER_AGENT'], 'Opera Mini') !== false
		|| strpos($_SERVER['HTTP_USER_AGENT'], 'Opera Mobi') !== false ) {
			$is_mobile = true;
	} else {
		$is_mobile = false;
	}
	return $is_mobile;
}

function wp_is_mobile_regex() {
	if ( empty($_SERVER['HTTP_USER_AGENT']) ) {
		$is_mobile = false;
	} elseif( preg_match( "/(Mobile|Android|Silk|Kindle|BlackBerry|Opera\sMini|Opera\sMobi)/", $_SERVER['HTTP_USER_AGENT'] ) ) {
		$is_mobile = true;	
	}else {
		$is_mobile = false;
	}
	return $is_mobile;
}

function microtime_float() {
    list($usec, $sec) = explode(" ", microtime());
    return ((float)$usec + (float)$sec);
}

//number of performed loops
$loops = 100000;

$user_agents = array(
	'Chrome' => 'Mozilla/5.0 (Macintosh; Intel Mac OS X 10_10_2) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/40.0.2214.94 Safari/537.36',
	'iPhone' => 'Mozilla/5.0 (iPhone; CPU iPhone OS 6_1_3 like Mac OS X) AppleWebKit/536.26 (KHTML, like Gecko) Version/6.0 Mobile/10B329 Safari/8536.25',
	'Opera Mobile' => 'Opera/12.02 (Android 4.1; Linux; Opera Mobi/ADR-1111101157; U; en-US) Presto/2.9.201 Version/12.02'
);

foreach( $user_agents as $browser => $user_agent ) {
	$_SERVER['HTTP_USER_AGENT'] = $user_agent;
	//WP default function
	$time_start = microtime_float();
	for( $i = 0; $i < $loops; $i++ ) {
		$is_mobile = wp_is_mobile();
	}
	$time_end = microtime_float();
	$result = ( true === $is_mobile ) ? 'true' : 'false';
	$time = $time_end - $time_start;
	echo "Performed {$loops} wp_is_mobile checks with result {$result} on {$browser}'s UA in {$time} seconds<br/>";
	
	//regex alternative
	$time_start = microtime_float();
	for( $i = 0; $i < $loops; $i++ ) {
		$is_mobile = wp_is_mobile_regex();
	}
	$time_end = microtime_float();
	$result = ( true === $is_mobile ) ? 'true' : 'false';
	$time = $time_end - $time_start;
	echo "Performed {$loops} wp_is_mobile_regex checks with result {$result} on {$browser}'s User Agent String in {$time} seconds<br/><br/>";
}

Results:

Performed 100000 wp_is_mobile checks with result false on Chrome's UA in 0.25132203102112 seconds
Performed 100000 wp_is_mobile_regex checks with result false on Chrome's User Agent String in 1.9904379844666 seconds

Performed 100000 wp_is_mobile checks with result true on iPhone's UA in 0.064327955245972 seconds
Performed 100000 wp_is_mobile_regex checks with result true on iPhone's User Agent String in 1.7663469314575 seconds

Performed 100000 wp_is_mobile checks with result true on Opera Mobile's UA in 0.11455106735229 seconds
Performed 100000 wp_is_mobile_regex checks with result true on Opera Mobile's User Agent String in 0.37428307533264 seconds