php实现Session存储到Redis

对于大访问量的站点使用默认的Session 并不合适，我们可以将其存入数据库、或者使用Redis KEY-VALUE数据存储方案
首先新建一个session表

    CREATE TABLE `sessions` (
     `sid` char(40) NOT NULL,
     `updatetime` int(20) NOT NULL,
     `data` varchar(200) NOT NULL,
     UNIQUE KEY `sid` (`sid`) USING HASH
    ) ENGINE=MEMORY DEFAULT CHARSET=utf8;

Mysql 的memory引擎采用内存表，所有数据存储在内存，操作速度快

    <?php
    //引入数据库文件
    include "db.php";
    class MySessionHandler implements SessionHandlerInterface
    {
      private $savePath;
      private $sessData;
      public $expiretime;  //设置过期时间
      public $db;  //数据库
      public function __construct($hanlder =''){

        $this->db = Database::getInstance();  

        //获取数据库实力 
        ///var_dump($this->db);

      }

      public function open($savePath, $sessionName)
      {

        return true;
      }

      public function close()
      {
        return true;
      }

      public function read($id)
      {  
        $sql ="select * from sessions where sid ='$id'";
        $result = $this->db->execute($sql);
          if(!empty($result)){
             return $this->sessData = $result;
          }
      }
          //函数的参数 $id -> 当前会话ID
          //数据DATA -> 序列化之后的字符串
      public function write($id, $data)
      {
        // echo $id;
        // echo $data;
        $now = time();
        $newExp = $now+$this->expiretime;  //总时间=当前时间 + 期限时间
        $sql = "select * from sessions where sid ='$id'";
        $result = $this->db->getOne($sql);
        //var_dump($result);
        if($data==''||isset($data)){
          $data = $this->sessData;
        }
          if($result){
          //如果存在则更新
      $sql ="update sessions set updatetime = '$newExp',data ='$data' where sid = '$id'";
            //echo $sql;
              $update_data =$this->db->execute($sql);
              if($update_data){
                return true;
              }

          }else{
          //不存在则生成生成
      $sql = "insert into sessions(sid,updatetime,data) values('$id','$now','$data')";
        $insert_data = $this->db->execute($sql);
        if($insert_data){
        return true;
            }
          }
          return false;
      }

      public function destroy($id)
      {    //销毁
        $sql = "delete from sessions where sid="."$id";
        $destory = $this->db->execute($sql);
        if($destory){
           return true;
        }else{
          return false;
        }
      }

      public function gc($sessMaxLifeTime)
      {
       $t = time();
      $sql ="delete from sessions where $t - 'updatetime'>${sessMaxLifeTime}";
        $data = $this->db->execute($this->tosql);
        if($data){
          return true;
        }else{
          return false;
          }
        return true;
      }
    }

实例化

此处 PHP 手册可以有两种方法
1，实现了SessionHandlerInterface借口的对象,自PHP5.4可以使用
2 ，直接使用 session_set_save_handler

     //判断PHP版本
     if(version_compare(PHP_VERSION,5.4)==1){

       session_set_save_handler($handler, true);
      session_start();
      }else{  
        ini_set('session.use_trans_sid',0);
        ini_set('session.use_cookies',1);
        ini_set('session.cookie_path','/');
          ini_set('session.save_handler','user');
          session_module_name('user');
          session_set_save_handler(array($session,"open"),array($session,"close"),array($session,"read"),array($session,"write"),array($session,"destory"),array($session,"gc"));
          session_start();   
         }
    $_SESSION['QQ']="QQ";
    echo $_SESSION['QQ'];

数据库代码

    <?php 
    class Database{
         static $instance;
        static $db;
      static function getInstance(){   
        if(self::$instance){
          return self::$instance;
        }else{
          return new Database();  
        }
      }
      public function __construct(){
        self::$db = new PDO('mysql:host=localhost;dbname=session', 'root','');
      }

        public function getOne($sql){
          $rs =self::$db->query($sql);
          @$rs->setFetchMode(PDO::FETCH_ASSOC);//返回关联数组
          $result = $rs -> fetch();
          return $result;
        }
        public function execute($sql){


            $rs = self::$db->exec($sql);
            return $rs;

        } 


    } 
    //$data = Database::getInstance();
    //var_dump($data);

使用REDIS 存储SESSION

    <?php
    class SessionManager{
      private $redis;
      private $sessionSavePath;
      private $sessionName;
      private $sessionExpireTime = 30;
      public function __construct(){
        $this->redis = new Redis();
        $this->redis->connect('127.0.0.1',6379);  //连接redis
        $retval = session_set_save_handler(
          array($this,"open"),
          array($this,"close"),
          array($this,"read"),
          array($this,"write"),
          array($this,"destory"),
          array($this,"gc")
        );
          session_start();
      }

        public function open($path,$name){
          return true;
        }
        public function close(){
          return true;
        }
        public function read($id){
          $value = $this->redis->get($id);
          if($value){
            return $value;
          }else{
            return "";
          }
        }
        public function write($id,$data){
          if($this->redis->set($id,$data)){
            $this->redis->expire($id,$this->sessionExpireTime); 
             //设置过期时间
            return true;
          }
          return false;
        }
        public function destory($id){
          if($this->redis->delete($id)){
            return true;
          }
          return false;
        }
        public function gc($maxlifetime){
          return true;
        }
        //析构函数
        public function __destruct(){
          session_write_close();
        }

    } 
    $re = new SessionManager();
    $_SESSION['name'] = "qq";
    echo $_SESSION['name'];

以上就是详细的介绍了php实现Session存储到Redis的方法，希望对大家的学习有所帮助。