PHP Timer 页面运行时间监测类

/** Timer class, 计算页面运行时间,可按不同key计算不同的运行时间 
*   Date:   2014-02-28 
*   Author: fdipzone 
*   Ver:    1.0 
* 
*   Func: 
*   public  start        记录开始时间 
*   public  end          记录结束时间 
*   public  getTime      计算运行时间 
*   pulbic  printTime    输出运行时间 
*   private getKey       获取key 
*   private getMicrotime 获取microtime 
*/  
  
class Timer{ // class start  
  
    private $_start = array();  
    private $_end = array();  
    private $_default_key = ‘Timer‘;  
    private $_prefix = ‘Timer_‘;  
  
  
    /** 记录开始时间 
    * @param String $key 标记 
    */  
    public function start($key=‘‘){  
        $flag = $this->getKey($key);  
        $this->_start[$flag] = $this->getMicrotime();  
    }  
  
  
    /** 记录结束时间 
    * @param String $key 标记 
    */  
    public function end($key=‘‘){  
        $flag = $this->getKey($key);  
        $this->_end[$flag] = $this->getMicrotime();  
    }  
  
  
    /** 计算运行时间 
    * @param  String $key 标记 
    * @return float 
    */  
    public function getTime($key=‘‘){  
        $flag = $this->getKey($key);  
        if(isset($this->_end[$flag]) && isset($this->_start[$flag])){  
            return (float)($this->_end[$flag] - $this->_start[$flag]);  
        }else{  
            return 0;  
        }  
    }  
  
  
    /** 输出页面运行时间 
    * @param  String $key 标记 
    * @return String 
    */  
    public function printTime($key=‘‘){  
        printf("%srun time %f ms\r\n", $key==‘‘? $key : $key.‘ ‘, $this->getTime($key)*1000);  
    }  
  
  
    /** 获取key 
    * @param  String $key 标记 
    * @return String  
    */  
    private function getKey($key=‘‘){  
        if($key==‘‘){  
            return $this->_default_key;  
        }else{  
            return $this->_prefix.$key;  
        }  
    }  
  
  
    /** 获取microtime 
    */  
    private function getMicrotime(){  
        list($usec, $sec) = explode(‘ ‘, microtime());  
        return (float)$usec + (float)$sec;  
    }  
  
  
} // class end

<?php  
  
require ‘Timer.class.php‘;  
  
$timer = new Timer();  
$timer->start();  
  
$timer->start(‘program1‘);  
usleep(mt_rand(100000,500000));  
$timer->end(‘program1‘);  
$timer->printTime(‘program1‘);  
  
$timer->start(‘program2‘);  
usleep(mt_rand(100000,500000));  
$timer->end(‘program2‘);  
$timer->printTime(‘program2‘);  
  
$timer->end();  
$timer->printTime();  
  
?>