/**
     * 排行榜
     */
    public function rank()
    {

        // $this->zrem($this->cachekey);
        $this->redis->del($this->cachekey);

        $dataOne = [];
        for ($i=0; $i < 5; $i++) { 
          
            // 生成随机数
            $num = rand(0,100);
            // 生成随机字符串
            $str = $this->get_random(6,'abcdefghijklmnopqrstuvwxyzABCDEFJHIJKLMNOPQRSTUVWXYZ');
            
            $this->redis->zadd($this->cachekey,$num,json_encode(['name'=>$str]));

            // 由大到小排序
            $dataOne = $this->redis->ZREVRANGE($this->cachekey, 0, -1, true);

            // 由小到大排序
            $dataTow = $this->redis->ZRANGE($this->cachekey, 0, -1, true);
        }

        echo "<pre>";
        print_r($dataOne);
        print_r($dataTow);

    }

    // 生成随机字符串
    public function get_random($len,$chars)
    {
        $hash = "";
        $max = strlen($chars) - 1;
        for ($i=0; $i < $len; $i++) { 
            $hash .= $chars[mt_rand(0,$max)];
        }
        return $hash;
    }