php 类静态变量 和 常量消耗内存及时间对比

在对类执行100w次循环后， 常量最快，变量其次，静态变量消耗时间最高

其中：

常量消耗：101.1739毫秒

变量消耗：2039.7689毫秒

静态变量消耗：4084.8911毫秒

测试代码：

class Timer_profiler {

    public static $begin_timer;

    public static $finish_timer;

    public static $timer_html;

    /**

     * 计算时间差

     * @return type

     */

    public static function getRecordTimer() {

        return (self::getFinishTimer() - self::getBeginTimer()) * 1000;

    }

    /**

     * 生成输出HTML

     * @param type $message

     * @return type

     */

    public static function recordHtml($message = '') {

        self::setFinishTimer();

        return "<p>{$message}耗时： " . self::getRecordTimer() . " 毫秒</p>";

    }

    /**

     * 设置开始时间

     */

    public static function setBeginTimer() {

        self::$begin_timer = self::getTime();

    }

    /**

     * 设置结束时间

     */

    public static function setFinishTimer() {

        self::$finish_timer = self::getTime();

    }

    /**

     * 获取开始时间

     * @return type

     */

    public static function getBeginTimer() {

        return self::$begin_timer;

    }

    /**

     * 获取结束时间

     * @return type

     */

    public static function getFinishTimer() {

        return self::$finish_timer;

    }

    /**

     * 获取带微妙的时间戳

     * @return type

     */

    private static function getTime() {

        list($usec, $sec) = explode(" ", microtime());

        return (number_format($sec+$usec,6,'.', ''));

    }

}

function computeTime($otime,$message){

    return;

    $ntime =  xdebug_time_index();

    $str = '';

    $str .= $message . ($ntime*1000-$otime*1000);

    $str .= "<br>";

    echo $str;

}

function getMemoryUsed(){

    $str = '消耗内存<h3 style="color:red"> ';

    $str .= round(memory_get_usage()/1024/1024, 4).'MB';

    $str .= '</h3>';

    echo $str;

}

$count_i = 100*10000;

//$count_i = 100000;

Timer_profiler::setBeginTimer();

computeTime(xdebug_time_index(),'开始执行');

echo Timer_profiler::recordHtml('开始执行');

getMemoryUsed();

class TestVar {

    public $A1 = 'aaaaaaaaaaaaaaaaa';

    public $A2 = 'aaaaaaaaaaaaaaaaa';

    public $A3 = 'aaaaaaaaaaaaaaaaa';

    public $A4 = 'aaaaaaaaaaaaaaaaa';

    public $A5 = 'aaaaaaaaaaaaaaaaa';

    public $A6 = 'aaaaaaaaaaaaaaaaa';

    public $A7 = 'aaaaaaaaaaaaaaaaa';

    public $A8 = 'aaaaaaaaaaaaaaaaa';

}

$TestVar = new TestVar();

for($i=0;$i<=$count_i;$i++){

    $t = $TestVar->A1;

    $t = $TestVar->A2;

    $t = $TestVar->A3;

    $t = $TestVar->A4;

    $t = $TestVar->A5;

    $t = $TestVar->A6;

    $t = $TestVar->A7;

    $t = $TestVar->A8;

}

getMemoryUsed();

echo Timer_profiler::recordHtml('变量完成');

computeTime(xdebug_time_index(),'变量完成');

Timer_profiler::setBeginTimer();

class TestStaticVar {

    static $A1 = 'aaaaaaaaaaaaaaaaa';

    static $A2 = 'aaaaaaaaaaaaaaaaa';

    static $A3 = 'aaaaaaaaaaaaaaaaa';

    static $A4 = 'aaaaaaaaaaaaaaaaa';

    static $A5 = 'aaaaaaaaaaaaaaaaa';

    static $A6 = 'aaaaaaaaaaaaaaaaa';

    static $A7 = 'aaaaaaaaaaaaaaaaa';

    static $A8 = 'aaaaaaaaaaaaaaaaa';

}

for($i=0;$i<=$count_i;$i++){

    $t = TestStaticVar::$A1;

    $t = TestStaticVar::$A2;

    $t = TestStaticVar::$A3;

    $t = TestStaticVar::$A4;

    $t = TestStaticVar::$A5;

    $t = TestStaticVar::$A6;

    $t = TestStaticVar::$A7;

    $t = TestStaticVar::$A8;

}

getMemoryUsed();

echo Timer_profiler::recordHtml('静态变量完成');

computeTime(xdebug_time_index(),'静态变量完成');

Timer_profiler::setBeginTimer();

class TestConstVar {

    const A1 = 'aaaaaaaaaaaaaaaaa';

    const A2 = 'aaaaaaaaaaaaaaaaa';

    const A3 = 'aaaaaaaaaaaaaaaaa';

    const A4 = 'aaaaaaaaaaaaaaaaa';

    const A5 = 'aaaaaaaaaaaaaaaaa';

    const A6 = 'aaaaaaaaaaaaaaaaa';

    const A7 = 'aaaaaaaaaaaaaaaaa';

    const A8 = 'aaaaaaaaaaaaaaaaa';

}

for($i=0;$i<=$count_i;$i++){

    $t = TestConstVar::A1;

    $t = TestConstVar::A2;

    $t = TestConstVar::A3;

    $t = TestConstVar::A4;

    $t = TestConstVar::A5;

    $t = TestConstVar::A6;

    $t = TestConstVar::A7;

    $t = TestConstVar::A8;

}

getMemoryUsed();

echo Timer_profiler::recordHtml('常量完成');

computeTime(xdebug_time_index(),'常量完成');

//echo Timer_profiler::recordHtml('共执行');

computeTime(xdebug_time_index(),'共执行');

exit;