tp6单例模式初始化redis

class Redis
{
    private static $_instance = null; //静态实例
    private function __construct(){ //私有的构造方法
        self::$_instance = Cache::store('redis');
    }
    /*
 * 禁止clone
 */
    private function __clone(){}
    //获取静态实例
    public static  function getRedis(){
        if(!self::$_instance){
            new self;
        }
        return self::$_instance;
    }

}