php計算頁面執行時間代碼

<?

class  c_Timer  { 
        var  $t_start  =  0; 
        var  $t_stop  =  0; 
        var  $t_elapsed  =  0;

    function  start()  {  $this->t_start  =  microtime();  } 

    function  stop()    {  $this->t_stop    =  microtime();  } 

    function  elapsed()  { 
            if  ($this->t_elapsed)  { 
                    return  $this->t_elapsed; 
            }  else  { 
                        $start_u  =  substr($this->t_start,0,10);   

$start_s  =  substr($this->t_start,11,10); 
                              $stop_u    =  substr($this->t_stop,0,10);

$stop_s    =  substr($this->t_stop,11,10); 
                        $start_total  =  doubleval($start_u)  +  $start_s; 
                              $stop_total    =  doubleval($stop_u)  +  $stop_s;

                    $this->t_elapsed  =  $stop_total  -  $start_total; 

                    return  $this->t_elapsed; 
            } 
    } 

};
/*  Here's  an  example  usage:

    $timer  =  new  c_Timer; 

    $timer->start(); 
    echo  "<hr>"; 
    $timer->stop(); 

    echo  $timer->elapsed(); 


*/ 
?>
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