PHP5 的動態函數/行為調用效率測試

我先前為了測試 PHP5 的 reflection 能力，找到《Benchmarking dynamic function/method calls》為參考文章，寫了一段效率測試碼。剛好今天看到 HACGIS 也做了《各種呼叫方式的比較》。因為 HACGIS 沒測到 reflection 的部份，所以把我的效率測試碼也放上來供各位參考。

<?php
class Benchmark {
    public $counter;
    public function __construct() {
        $this->counter = 0;
    }
    public function increase($c, $b, $a) {
       //echo 'counter a = ', $a, "\n";
       //echo 'counter b = ', $b, "\n";
       //echo 'counter c = ', $c, "\n";
       $this->counter += $c;
       return;
    }
}

$times = 1000000;
$benchmark = new Benchmark();
$unorderedParameters = array(
    'b' => 1,
    'a' => 100,
    'c' => 13
);

// Get an instance of the ReflectionMethod class by an ojbect
$funcName = 'increase';
$func = new ReflectionMethod($benchmark, $funcName);
if ($parameters = $func->getParameters()) {
    $i = 0;
    foreach ($parameters as $parameter) {
        $k = $parameter->getName();
        $orderedParameters[$i++] = $unorderedParameters[$k];
    }
}

printf("---> Invokation arguments: \n");
var_dump($unorderedParameters);

echo "Straight method call: \n";
$benchmark->counter = 0;
$start = microtime(true);
for ($i = 0; $i < $times; $i++) {
    $benchmark->increase($unorderedParameters['c'], $unorderedParameters['b'], $unorderedParameters['a']);
}
$end = microtime(true);
$elapsed = $end - $start;
echo 'result is ', $benchmark->counter, ', elapsed : ', $elapsed, ' secs', "\n";


echo "Variable method call: \n";
$benchmark->counter = 0;
$start = microtime(true);
for ($i = 0; $i < $times; $i++) {
    $benchmark->$funcName($unorderedParameters['c'], $unorderedParameters['b'], $unorderedParameters['a']);
}
$end = microtime(true);
$elapsed = $end - $start;
echo 'result is ', $benchmark->counter, ', elapsed : ', $elapsed, ' secs', "\n";


echo "invoke method call: \n";
$benchmark->counter = 0;
$start = microtime(true);
for ($i = 0; $i < $times; $i++) {
    $func->invoke($benchmark, $unorderedParameters['c'], $unorderedParameters['b'], $unorderedParameters['a']);
}
$end = microtime(true);
$elapsed = $end - $start;
echo 'result is ', $benchmark->counter, ', elapsed : ', $elapsed, ' secs', "\n";


echo "invokeArgs method call: \n";
$benchmark->counter = 0;
$start = microtime(true);
for ($i = 0; $i < $times; $i++) {
    $func->invokeArgs($benchmark, $orderedParameters);
}
$end = microtime(true);
$elapsed = $end - $start;
echo 'result is ', $benchmark->counter, ', elapsed : ', $elapsed, ' secs', "\n";


echo "call_user_func_array method call: \n";
$benchmark->counter = 0;
$start = microtime(true);
$m = array(&$benchmark, $funcName);
for ($i = 0; $i < $times; $i++) {
    call_user_func_array($m, $orderedParameters);
}
$end = microtime(true);
$elapsed = $end - $start;
echo 'result is ', $benchmark->counter, ', elapsed : ', $elapsed, ' secs', "\n";

?>

結論... reflection 這個在 Java/C# 中的高等技巧，在 PHP 這種動態語言中就顯得有些多餘了。當行為名稱及參數個數及順序已知時，傳統調用方法的效率無疑是最好的。當參數個數及順序未知時，使用 call_user_func_array() 也比 Reflection::invokeArgs() 來得好些。

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