system/libraries/Cache/drivers/Cache_memcached.php

<?php
/**
 * CodeIgniter
 *
 * An open source application development framework for PHP 5.2.4 or newer
 *
 * NOTICE OF LICENSE
 *
 * Licensed under the Open Software License version 3.0
 *
 * This source file is subject to the Open Software License (OSL 3.0) that is
 * bundled with this package in the files license.txt / license.rst.  It is
 * also available through the world wide web at this URL:
 * http://opensource.org/licenses/OSL-3.0
 * If you did not receive a copy of the license and are unable to obtain it
 * through the world wide web, please send an email to
 * licensing@ellislab.com so we can send you a copy immediately.
 *
 * @package		CodeIgniter
 * @author		EllisLab Dev Team
 * @copyright	Copyright (c) 2008 - 2012, EllisLab, Inc. (http://ellislab.com/)
 * @license		http://opensource.org/licenses/OSL-3.0 Open Software License (OSL 3.0)
 * @link		http://codeigniter.com
 * @since		Version 2.0
 * @filesource
 */
defined('BASEPATH') OR exit('No direct script access allowed');

/**
 * CodeIgniter Memcached Caching Class
 *
 * @package		CodeIgniter
 * @subpackage	Libraries
 * @category	Core
 * @author		EllisLab Dev Team
 * @link
 */
class CI_Cache_memcached extends CI_Driver {

	/**
	 * Holds the memcached object
	 *
	 * @var object
	 */
	protected $_memcached;

	/**
	 * Memcached configuration
	 *
	 * @var array
	 */
	protected $_memcache_conf	= array(
		'default' => array(
			'default_host'		=> '127.0.0.1',
			'default_port'		=> 11211,
			'default_weight'	=> 1
		)
	);

	/**
	 * Fetch from cache
	 *
	 * @param	mixed	unique key id
	 * @return	mixed	data on success/false on failure
	 */
	public function get($id)
	{
		$data = $this->_memcached->get($id);

		return is_array($data) ? $data[0] : FALSE;
	}

	// ------------------------------------------------------------------------

	/**
	 * Save
	 *
	 * @param	string	unique identifier
	 * @param	mixed	data being cached
	 * @param	int	time to live
	 * @return	bool	true on success, false on failure
	 */
	public function save($id, $data, $ttl = 60)
	{
		if (get_class($this->_memcached) === 'Memcached')
		{
			return $this->_memcached->set($id, array($data, time(), $ttl), $ttl);
		}
		elseif (get_class($this->_memcached) === 'Memcache')
		{
			return $this->_memcached->set($id, array($data, time(), $ttl), 0, $ttl);
		}

		return FALSE;
	}

	// ------------------------------------------------------------------------

	/**
	 * Delete from Cache
	 *
	 * @param	mixed	key to be deleted.
	 * @return	bool	true on success, false on failure
	 */
	public function delete($id)
	{
		return $this->_memcached->delete($id);
	}

	// ------------------------------------------------------------------------

	/**
	 * Clean the Cache
	 *
	 * @return	bool	false on failure/true on success
	 */
	public function clean()
	{
		return $this->_memcached->flush();
	}

	// ------------------------------------------------------------------------

	/**
	 * Cache Info
	 *
	 * @return	mixed	array on success, false on failure
	 */
	public function cache_info()
	{
		return $this->_memcached->getStats();
	}

	// ------------------------------------------------------------------------

	/**
	 * Get Cache Metadata
	 *
	 * @param	mixed	key to get cache metadata on
	 * @return	mixed	FALSE on failure, array on success.
	 */
	public function get_metadata($id)
	{
		$stored = $this->_memcached->get($id);

		if (count($stored) !== 3)
		{
			return FALSE;
		}

		list($data, $time, $ttl) = $stored;

		return array(
			'expire'	=> $time + $ttl,
			'mtime'		=> $time,
			'data'		=> $data
		);
	}

	// ------------------------------------------------------------------------

	/**
	 * Setup memcached.
	 *
	 * @return	bool
	 */
	protected function _setup_memcached()
	{
		// Try to load memcached server info from the config file.
		$CI =& get_instance();

		if ($CI->config->load('memcached', TRUE, TRUE))
		{
			if (is_array($CI->config->config['memcached']))
			{
				$this->_memcache_conf = NULL;

				foreach ($CI->config->config['memcached'] as $name => $conf)
				{
					$this->_memcache_conf[$name] = $conf;
				}
			}
		}

		if (class_exists('Memcached'))
		{
			$this->_memcached = new Memcached();
		}
		elseif (class_exists('Memcache'))
		{
			$this->_memcached = new Memcache();
		}
		else
		{
			log_message('error', 'Failed to create object for Memcached Cache; extension not loaded?');
			return FALSE;
		}

		foreach ($this->_memcache_conf as $name => $cache_server)
		{
			if ( ! array_key_exists('hostname', $cache_server))
			{
				$cache_server['hostname'] = $this->_memcache_conf['default']['default_host'];
			}

			if ( ! array_key_exists('port', $cache_server))
			{
				$cache_server['port'] = $this->_memcache_conf['default']['default_port'];
			}

			if ( ! array_key_exists('weight', $cache_server))
			{
				$cache_server['weight'] = $this->_memcache_conf['default']['default_weight'];
			}

			if (get_class($this->_memcached) === 'Memcache')
			{
				// Third parameter is persistance and defaults to TRUE.
				$this->_memcached->addServer(
					$cache_server['hostname'],
					$cache_server['port'],
					TRUE,
					$cache_server['weight']
				);
			}
			else
			{
				$this->_memcached->addServer(
					$cache_server['hostname'],
					$cache_server['port'],
					$cache_server['weight']
				);
			}
		}

		return TRUE;
	}

	// ------------------------------------------------------------------------

	/**
	 * Is supported
	 *
	 * Returns FALSE if memcached is not supported on the system.
	 * If it is, we setup the memcached object & return TRUE
	 *
	 * @return	bool
	 */
	public function is_supported()
	{
		if ( ! extension_loaded('memcached') && ! extension_loaded('memcache'))
		{
			log_message('error', 'The Memcached Extension must be loaded to use Memcached Cache.');
			return FALSE;
		}

		return $this->_setup_memcached();
	}

}

/* End of file Cache_memcached.php */
/* Location: ./system/libraries/Cache/drivers/Cache_memcached.php */