<?php  
        
    class redisCache {  
       /** 
        * $host : redis服务器ip 
        * $port : redis服务器端口 
        * $lifetime : 缓存文件有效期,单位为秒 
        * $cacheid : 缓存文件路径,包含文件名 
       */  
       private $host;  
       private $port;  
       private $lifetime;  
       private $cacheid;  
       private $data;  
       public $redis;  
       /** 
        * 析构函数,检查缓存目录是否有效,默认赋值 
       */  
       function __construct($lifetime=1800) {  
            //配置  
            $this->host = "127.0.0.1";  
            $this->port = "6379";  
            $redis = new Redis();   
            $redis->pconnect($this->host,$this->port);   
            $this->redis=$redis;  
            $this->cacheid = $this->getcacheid();  
            $this->lifetime = $lifetime;  
            $this->data=$redis->hMGet($this->cacheid, array('content','creattime'));  
            //print_r($this->redis);  
            //print_r($this->data);  
       }  
       
       
       /** 
        * 检查缓存是否有效 
       */  
       private function isvalid(){  
           $data=$this->data;  
           if (!$data['content']) return false;  
           if (time() - $data['creattime'] > $this->lifetime) return false;  
           return true;  
       }  
       /** 
        * 写入缓存 
        * $mode == 0 , 以浏览器缓存的方式取得页面内容 
       */  
       public function write($mode=0,$content='') {  
           switch ($mode) {  
               case 0:  
                   $content = ob_get_contents();  
                   break;  
               default:  
                   break;  
           }  
           ob_end_flush();  
           try {  
                $this->redis->hMset($this->cacheid, array('content'=>$content,'creattime'=>time()));  
                $this->redis->expireAt($this->cacheid, time() + $this->lifetime);  
           }  
           catch (Exception $e) {  
               $this->error('写入缓存失败!');  
           }  
       }  
       /** 
        * 加载缓存 
        * exit() 载入缓存后终止原页面程序的执行,缓存无效则运行原页面程序生成缓存 
        * ob_start() 开启浏览器缓存用于在页面结尾处取得页面内容 
       */  
       public function load() {  
           if ($this->isvalid()) {  
               echo $this->data['content'];  
               exit();  
           }  
           else {  
               ob_start();  
           }  
       }  
       /** 
        * 清除缓存 
       */  
       public function clean() {  
           try {  
               $this->redis->hDel($this->cacheid, array('content','creattime'));  
           }  
           catch (Exception $e) {  
               $this->error('清除缓存失败!');  
           }  
       }  
       /** 
        * 取得缓存文件路径 
       */  
       private function getcacheid() {  
           return $this->dir.md5($this->geturl()).$this->ext;  
       }  
       /** 
        * 取得当前页面完整url 
       */  
       private function geturl() {  
           $url = '';  
           if (isset($_SERVER['REQUEST_URI'])) {  
               $url = $_SERVER['REQUEST_URI'];  
           }  
           else {  
               $url = $_SERVER['Php_SELF'];  
               $url .= empty($_SERVER['QUERY_STRING'])?'':'?'.$_SERVER['QUERY_STRING'];  
           }  
           return $url;  
       }  
       /** 
        * 输出错误信息 
       */  
       private function error($str) {  
           echo '<div style="color:red;">'.$str.'</div>';  
       }  
    }  
       
       
    //用法：  
    // require_once('redisCache.php');  
    // $cache = new redisCache(10); //设置缓存生存期  
    // if ($_GET['clearCache']) $cache->clean();  
    // else  $cache->load(); //装载缓存,缓存有效则不执行以下页面代码  
    // //页面代码开始  
       
    // //页面代码结束  
    // $cache->write(); //首次运行或缓存过期,生成缓存  
       
       
       
    ?>