<?php
/**
 * SimplePie
 *
 * A PHP-Based RSS and Atom Feed Framework.
 * Takes the hard work out of managing a complete RSS/Atom solution.
 *
 * Copyright (c) 2004-2016, 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
 * @copyright 2004-2016 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_',
            ),
        );
        $this->options = SimplePie_Misc::array_merge_recursive($this->options, SimplePie_Cache::parse_URL($location));

        $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 its 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->options['extras']['timeout']);
        }

        return false;
    }

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