<?php
  
  /*
   * This file is part of the Assetic package, an OpenSky project.
   *
   * (c) 2010-2014 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);
      }
  }