PHP清除Memcache过期缓存程序代码

/**
* Memcached的过期内存回收
*/
class mem_dtor extends Memcache
{
private $server_id;
public function __construct($host,$port)
{
$this->server_id = "$host:$port";
$this->connect($host,$port);
}

// 回收所有过期的内存
public function gc()
{
$t = time();
$_this = $this;
$func = function($key,$info) use ($t,$_this)
{
if($info[1] - $t delete($key);
}
};
$this->lists($func);
}

// 查看所有缓存内容的信息
public function info()
{
$t = time();
$func = function($key,$info) use ($t)
{
echo $key,' => Exp:',$info[1] - $t,"n"; //查看缓存对象的剩余过期时间
};
$this->lists($func);
}

private function lists($func)
{
$sid = $this->server_id;
$items = $this->getExtendedStats('items'); //获取memcached状态
foreach($items[$sid]['items'] as $slab_id => $slab) //获取指定server id 的 所有Slab
{
$item = $this->getExtendedStats('cachedump',$slab_id,0); //遍历所有Slab
foreach($item[$sid] as $key => $info) //获取Slab中缓存对象信息
{
$func($key,$info);
}
}
}
}

$mem = new mem_dtor('127.0.0.1',11211);
$mem->info();//查看状态
$mem->gc(); //回收