php CI框架中调用接口 memcache缓存数据

<?php
defined('BASEPATH') OR exit('No direct script access allowed');
class Welcome extends CI_Controller {
   
    public function index($page=1){
   
        $search=isset($_GET['search'])?$_GET['search']:'';
        //调用（天气）接口
        $appkey="19796";
        $json="b56fa8c7336906e546d0d6426a17fd70";
        $url="http://api.k780.com:88/?app=weather.future&weaid=1&&appkey=".$appkey."&sign=".$json."&format=json";
        $fil=file_get_contents($url);
        //转换json数组
        $arr=json_decode($fil,true);
        //循环输出值   
        foreach($arr['result'] as $k=>$v){
   
          $data=array('days'=>