<?php

/*

 * This file is part of the Assetic package, an OpenSky project.

 *

 * (c) 2010-2011 OpenSky Project Inc

 *

 * For the full copyright and license information, please view the LICENSE

 * file that was distributed with this source code.

 */

namespace Assetic\Cache;

/**

 * Adds expiration to a cache backend.

 *

 * @author Kris Wallsmith <kris.wallsmith@gmail.com>

 */

class ExpiringCache implements CacheInterface

{

    private $cache;

    private $lifetime;

    public function __construct(CacheInterface $cache, $lifetime)

    {

        $this->cache = $cache;

        $this->lifetime = $lifetime;

    }

    public function has($key)

    {

        if ($this->cache->has($key)) {

            if (time() < $this->cache->get($key.'.expires')) {

                return true;

            }

            $this->cache->remove($key.'.expires');

            $this->cache->remove($key);

        }

        return false;

    }

    public function get($key)

    {

        return $this->cache->get($key);

    }

    public function set($key, $value)

    {

        $this->cache->set($key.'.expires', time() + $this->lifetime);

        $this->cache->set($key, $value);

    }

    public function remove($key)

    {

        $this->cache->remove($key.'.expires');

        $this->cache->remove($key);

    }

}