php+redis缓存类详解大数据

php+redis缓存类

    <?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   
        
        
        
    ?>