php实现的redis缓存类定义与使用方法示例

<?phpclass 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?>