php+redis缓存类

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

?>