fotd.php

<?php
// See: http://blog.liip.ch/archive/2008/09/18/fotd-reflectionclass-newinstanceargs-args-is-slow.html
/* Results on my box:

$ php -v
PHP 5.2.6-pl7-gentoo (cli) (built: Sep 22 2008 08:13:50) 
Copyright (c) 1997-2008 The PHP Group
Zend Engine v2.2.0, Copyright (c) 1998-2008 Zend Technologies

$ php test.php 
A
init	0.2247450352
init2	0.2754812241
init3	not applicable.
init4	0.9950580597
init5	0.9901609421

B
init	0.5811409950
init2	0.6747829914
init3	0.4714331627
init4	1.4021868706
init5	1.4017899036

*/
class Base {
    function __toString() {
        return implode(":", array($this->a,
            $this->b,
            $this->c,
            $this->d,
            $this->e,
            $this->f));
    }
}

class A extends Base {
    function __construct($a=null, $b=null, $c=null, $d=null, $e=null, $f=null) {
        $this->a = $a;
        $this->b = $b;
        $this->c = $c;
        $this->d = $d;
        $this->e = $e;
        $this->f = $f;
    }
}

class B extends Base {
    function __construct($args=null) {
        $argnames = array(
            "a"=>null,
            "b"=>null,
            "c"=>null,
            "d"=>null,
            "e"=>null,
            "f"=>null);
        
        $args = is_array($args) && func_num_args() == 1 ?
            $args :
            func_get_args();

        $i=0;
        foreach($argnames as $arg => $defaultvalue) {
            ${$arg} = isset($args[$i]) ?
                $args[$i] :
                $defaultvalue;
            $i++;
        }

        $this->a = $a;
        $this->b = $b;
        $this->c = $c;
        $this->d = $d;
        $this->e = $e;
        $this->f = $f;
    }
}


function init($name,$init) {
    switch(count($init)) {
        case 0:
          return new $name();
        case 1:
          return new $name($init[0]);
        case 2:
          return new $name($init[0],$init[1]);
        case 3:
          return new $name($init[0],$init[1],$init[2]);
        case 4: 
          return new $name($init[0],$init[1],$init[2],$init[3]);
        case 5: 
          return new $name($init[0],$init[1],$init[2],$init[3],$init[4]);
        case 6: 
          return new $name($init[0],$init[1],$init[2],$init[3],$init[4],$init[5]);
     }
}

function init2($name,$init) {
    if (count($init) == 0) {
        return new $name();
    } else {
        $classObj = new ReflectionClass($name);
        return $classObj->newInstanceArgs($init);
    }
}

function init3($name, $init) {
    return new $name($init);
}

// from: Robin Orheden
function init4($name, $init) {
    $args = "\$init[" . implode("], \$init[", array_keys($init)) . "]";
    return class_exists($name) ? eval("return new {$name}({$args});") : false;
}

// using reflection
function init5($name,$init) {
    if (count($init) == 0) {
        return new $name();
    } else {
        $classObj = new ReflectionClass($name);
        return $classObj->newInstanceArgs($init);
    }
}

function measure($num, $fn, $class, $args) {
    $now = time()+microtime();
    for($i=0; $i<$num; $i++) {
        $fn($class, $args);
    }
    return time()+microtime() - $now;
}

$args = array("a", "b", "c", "d", "e", "f");
$num = 32000;
$view = "%.10f";

new A();
new B();

echo "A\n";
echo "init\t", sprintf($view, measure($num, "init", "A", $args)), "\n";
echo "init2\t", sprintf($view, measure($num, "init2", "A", $args)), "\n";
echo "init3\tnot applicable.\n";
echo "init4\t", sprintf($view, measure($num, "init4", "A", $args)), "\n";
echo "init5\t", sprintf($view, measure($num, "init4", "A", $args)), "\n";
echo "\n";
echo "B\n";
echo "init\t", sprintf($view, measure($num, "init", "B", $args)), "\n";
echo "init2\t", sprintf($view, measure($num, "init2", "B", $args)), "\n";
echo "init3\t", sprintf($view, measure($num, "init3", "B", $args)), "\n";
echo "init4\t", sprintf($view, measure($num, "init4", "B", $args)), "\n";
echo "init5\t", sprintf($view, measure($num, "init4", "B", $args)), "\n";

• What's different in init2() (line 99) and init5() (line 119) ?
• Running the test measurements, for "init5" you're still "init4" with A (line 148) and B (155) ?

So this means the measurement for "init2" which uses reflection with A isn't that bad.