<?php
/**
 * SimplePie
 *
 * A PHP-Based RSS and Atom Feed Framework.
 * Takes the hard work out of managing a complete RSS/Atom solution.
 *
 * Copyright (c) 2004-2012, Ryan Parman, Geoffrey Sneddon, Ryan McCue, and contributors
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without modification, are
 * permitted provided that the following conditions are met:
 *
 * 	* Redistributions of source code must retain the above copyright notice, this list of
 * 	  conditions and the following disclaimer.
 *
 * 	* Redistributions in binary form must reproduce the above copyright notice, this list
 * 	  of conditions and the following disclaimer in the documentation and/or other materials
 * 	  provided with the distribution.
 *
 * 	* Neither the name of the SimplePie Team nor the names of its contributors may be used
 * 	  to endorse or promote products derived from this software without specific prior
 * 	  written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY EXPRESS
 * OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY
 * AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDERS
 * AND CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
 * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
 * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGE.
 *
 * @package SimplePie
 * @version 1.3
 * @copyright 2004-2012 Ryan Parman, Geoffrey Sneddon, Ryan McCue
 * @author Ryan Parman
 * @author Geoffrey Sneddon
 * @author Ryan McCue
 * @link http://simplepie.org/ SimplePie
 * @license http://www.opensource.org/licenses/bsd-license.php BSD License
 */

/**
 * Caches data to memcache
 *
 * Registered for URLs with the "memcache" protocol
 *
 * For example, `memcache://localhost:11211/?timeout=3600&prefix=sp_` will
 * connect to memcache on `localhost` on port 11211. All tables will be
 * prefixed with `sp_` and data will expire after 3600 seconds
 *
 * @package SimplePie
 * @subpackage Caching
 * @uses Memcache
 */
class SimplePie_Cache_Memcache implements SimplePie_Cache_Base
{
	/**
	 * Memcache instance
	 *
	 * @var Memcache
	 */
	protected $cache;

	/**
	 * Options
	 *
	 * @var array
	 */
	protected $options;

	/**
	 * Cache name
	 *
	 * @var string
	 */
	protected $name;

	/**
	 * Create a new cache object
	 *
	 * @param string $location Location string (from SimplePie::$cache_location)
	 * @param string $name Unique ID for the cache
	 * @param string $type Either TYPE_FEED for SimplePie data, or TYPE_IMAGE for image data
	 */
	public function __construct($location, $name, $type)
	{
		$this->options = array(
			'host' => '127.0.0.1',
			'port' => 11211,
			'extras' => array(
				'timeout' => 3600, // one hour
				'prefix' => 'simplepie_',
			),
		);
		$parsed = SimplePie_Cache::parse_URL($location);
		$this->options['host'] = empty($parsed['host']) ? $this->options['host'] : $parsed['host'];
		$this->options['port'] = empty($parsed['port']) ? $this->options['port'] : $parsed['port'];
		$this->options['extras'] = array_merge($this->options['extras'], $parsed['extras']);
		$this->name = $this->options['extras']['prefix'] . md5("$name:$type");

		$this->cache = new Memcache();
		$this->cache->addServer($this->options['host'], (int) $this->options['port']);
	}

	/**
	 * Save data to the cache
	 *
	 * @param array|SimplePie $data Data to store in the cache. If passed a SimplePie object, only cache the $data property
	 * @return bool Successfulness
	 */
	public function save($data)
	{
		if ($data instanceof SimplePie)
		{
			$data = $data->data;
		}
		return $this->cache->set($this->name, serialize($data), MEMCACHE_COMPRESSED, (int) $this->options['extras']['timeout']);
	}

	/**
	 * Retrieve the data saved to the cache
	 *
	 * @return array Data for SimplePie::$data
	 */
	public function load()
	{
		$data = $this->cache->get($this->name);

		if ($data !== false)
		{
			return unserialize($data);
		}
		return false;
	}

	/**
	 * Retrieve the last modified time for the cache
	 *
	 * @return int Timestamp
	 */
	public function mtime()
	{
		$data = $this->cache->get($this->name);

		if ($data !== false)
		{
			// essentially ignore the mtime because Memcache expires on it's own
			return time();
		}

		return false;
	}

	/**
	 * Set the last modified time to the current time
	 *
	 * @return bool Success status
	 */
	public function touch()
	{
		$data = $this->cache->get($this->name);

		if ($data !== false)
		{
			return $this->cache->set($this->name, $data, MEMCACHE_COMPRESSED, (int) $this->duration);
		}

		return false;
	}

	/**
	 * Remove the cache
	 *
	 * @return bool Success status
	 */
	public function unlink()
	{
		return $this->cache->delete($this->name, 0);
	}
}
