<?php
class redisCache {
  /**
  * $host : redis服務器ip
  * $port : redis服務器端口
  * $lifetime : 緩存文件有效期,單位為秒
  * $cacheid : 緩存文件路徑,包含文件名
  */
  private $host;
  private $port;
  private $lifetime;
  private $cacheid;
  private $data;
  public $redis;
  /**
  * 析構(gòu)函數(shù),檢查緩存目錄是否有效,默認賦值
  */
  function __construct($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);
  }
  /**
  * 檢查緩存是否有效
  */
  private function isvalid(){
    $data=$this->data;
    if (!$data['content']) return false;
    if (time() - $data['creattime'] > $this->lifetime) return false;
    return true;
  }
  /**
  * 寫入緩存
  * $mode == 0 , 以瀏覽器緩存的方式取得頁面內(nèi)容
  */
  public function write($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) {
      $this->error('寫入緩存失敗!');
    }
  }
  /**
  * 加載緩存
  * exit() 載入緩存后終止原頁面程序的執(zhí)行,緩存無效則運行原頁面程序生成緩存
  * ob_start() 開啟瀏覽器緩存用于在頁面結(jié)尾處取得頁面內(nèi)容
  */
  public function load() {
    if ($this->isvalid()) {
      echo $this->data['content'];
      exit();
    }
    else {
      ob_start();
    }
  }
  /**
  * 清除緩存
  */
  public function clean() {
    try {
      $this->redis->hDel($this->cacheid, array('content','creattime'));
    }
    catch (Exception $e) {
      $this->error('清除緩存失敗!');
    }
  }
  /**
  * 取得緩存文件路徑
  */
  private function getcacheid() {
    return $this->dir.md5($this->geturl()).$this->ext;
  }
  /**
  * 取得當前頁面完整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 $url;
  }
  /**
  * 輸出錯誤信息
  */
  private function error($str) {
    echo '<div style="color:red;">'.$str.'</div>';
  }
}
//用法：
// require_once('redisCache.php');
// $cache = new redisCache(10); //設(shè)置緩存生存期
// if ($_GET['clearCache']) $cache->clean();
// else $cache->load(); //裝載緩存,緩存有效則不執(zhí)行以下頁面代碼
// //頁面代碼開始
// //頁面代碼結(jié)束
// $cache->write(); //首次運行或緩存過期,生成緩存
?>