单例模式 Redis

//购物车单例模式
class CartSingleton{
    //三私一公
    //定义一个静态的私变量
    static private $_instance=null;
    private $redis = null;

    //私有的构造方法
    private final function __construct(){
        //实例化
        $this->redis = new Redis();
        $this->redis->connect('127.0.0.1',6379);
    }

    //私有的克隆方法
    private function __clone(){

    }

    //公有的静态方法
    static public function getInstance(){
        if(!(self::$_instance instanceof self)){
            self::$_instance = new CartSingleton();
        }
        return self::$_instance;
    }

    //加入购物车
    public function addCart($userId,$gid,$gname){
        //hash键名
        $hashKey = "user_".$userId;
        //键名
        $key = $gid."_".$gname;
        //加入
        //return $gname;
        return $this->redis->hIncrBy($hashKey,$key,1);
    }

    //购物车列表
    public function cartList($userId){
        $hashKey = "user_".$userId;
        //查询
        return $this->redis->hGetAll($hashKey);
    }

    //清空原有的数据
    public function dell($userId,$gid,$gname){
        return $this->redis->flushAll();
    }

    //购物车单删
    public function cartDel($userId,$gid,$gname){
        $hashKey = "user_".$userId;
        $key = $gid."_".$gname;
        //删除
        return $this->redis->hDel($hashKey,$key);
    }

    //清空购物车
    public function delall($userId){
        $hashKey = "user_".$userId;
        return $this->redis->del($hashKey);
    }
}