老雷PHP全栈开发教程之PHP缓存的使用

<?php
ob_start();
echo "Hello World";
$out1 = ob_get_contents();
ob_end_flush();
file_put_contents("ob.html",$out1);
ob_start();
 $content=ob_get_contents(); 
 ob_end_clean();
？>

<?php
  cache::set("a","1");
  echo cache::get("a");
  $mem=new memcache();
  $mem->connect('localhost', 11211);
  $mem->set("aa","aa",0,30);
  echo $mem->get("aa");
  $redis=new Redis();
  $redis->connect('127.0.0.1', 6379);
  $redis->set("rk","redis缓存",30);
  echo $redis->get("rk");
  class cache{
    public static $dir="cache";
    public static function set($k,$v,$expire=12345678){
      $md5=md5($k);//有可能会冲突
      //md5值切割成目录a/b/c/$k
      $content=serialize(array(
        "value"=>$v,
        "expire"=>time()+$expire
      ));
      file_put_contents(self::$dir."/".$k,$content);
    }
    public static function get($k){
      $md5=md5($k);
      if(!file_exists(self::$dir."/".$k)){
        return false;
      }
      $c=file_get_contents(self::$dir."/".$k);
      $arr=unserialize($c);
      if($arr["expire"]<time()){
        return false;
      }
      return $arr["value"];
    }
  }


?>