Subversion Repositories SmartDukaan

<?php

/**

 * Memcache storage engine for cache

 *

 * CakePHP(tm) : Rapid Development Framework (http://cakephp.org)

 * Copyright (c) Cake Software Foundation, Inc. (http://cakefoundation.org)

 *

 * Licensed under The MIT License

 * For full copyright and license information, please see the LICENSE.txt

 * Redistributions of files must retain the above copyright notice.

 *

 * @copyright     Copyright (c) Cake Software Foundation, Inc. (http://cakefoundation.org)

 * @link          http://cakephp.org CakePHP(tm) Project

 * @package       Cake.Cache.Engine

 * @since         CakePHP(tm) v 1.2.0.4933

 * @license       http://www.opensource.org/licenses/mit-license.php MIT License

 */

/**

 * Memcache storage engine for cache. Memcache has some limitations in the amount of

 * control you have over expire times far in the future. See MemcacheEngine::write() for

 * more information.

 *

 * @package       Cake.Cache.Engine

 */

class MemcacheEngine extends CacheEngine {

/**

 * Contains the compiled group names

 * (prefixed with the global configuration prefix)

 *

 * @var array

 */

	protected $_compiledGroupNames = array();

/**

 * Memcache wrapper.

 *

 * @var Memcache

 */

	protected $_Memcache = null;

/**

 * Settings

 *

 *  - servers = string or array of memcache servers, default => 127.0.0.1. If an

 *    array MemcacheEngine will use them as a pool.

 *  - compress = boolean, default => false

 *

 * @var array

 */

	public $settings = array();

/**

 * Initialize the Cache Engine

 *

 * Called automatically by the cache frontend

 * To reinitialize the settings call Cache::engine('EngineName', [optional] settings = array());

 *

 * @param array $settings array of setting for the engine

 * @return boolean True if the engine has been successfully initialized, false if not

 */

	public function init($settings = array()) {

		if (!class_exists('Memcache')) {

			return false;

		}

		if (!isset($settings['prefix'])) {

			$settings['prefix'] = Inflector::slug(APP_DIR) . '_';

		}

		$settings += array(

			'engine' => 'Memcache',

			'servers' => array('127.0.0.1'),

			'compress' => false,

			'persistent' => true

		);

		parent::init($settings);

		if ($this->settings['compress']) {

			$this->settings['compress'] = MEMCACHE_COMPRESSED;

		}

		if (is_string($this->settings['servers'])) {

			$this->settings['servers'] = array($this->settings['servers']);

		}

		if (!isset($this->_Memcache)) {

			$return = false;

			$this->_Memcache = new Memcache();

			foreach ($this->settings['servers'] as $server) {

				list($host, $port) = $this->_parseServerString($server);

				if ($this->_Memcache->addServer($host, $port, $this->settings['persistent'])) {

					$return = true;

				}

			}

			return $return;

		}

		return true;

	}

/**

 * Parses the server address into the host/port. Handles both IPv6 and IPv4

 * addresses and Unix sockets

 *

 * @param string $server The server address string.

 * @return array Array containing host, port

 */

	protected function _parseServerString($server) {

		if ($server[0] === 'u') {

			return array($server, 0);

		}

		if (substr($server, 0, 1) === '[') {

			$position = strpos($server, ']:');

			if ($position !== false) {

				$position++;

			}

		} else {

			$position = strpos($server, ':');

		}

		$port = 11211;

		$host = $server;

		if ($position !== false) {

			$host = substr($server, 0, $position);

			$port = substr($server, $position + 1);

		}

		return array($host, $port);

	}

/**

 * Write data for key into cache. When using memcache as your cache engine

 * remember that the Memcache pecl extension does not support cache expiry times greater

 * than 30 days in the future. Any duration greater than 30 days will be treated as never expiring.

 *

 * @param string $key Identifier for the data

 * @param mixed $value Data to be cached

 * @param integer $duration How long to cache the data, in seconds

 * @return boolean True if the data was successfully cached, false on failure

 * @see http://php.net/manual/en/memcache.set.php

 */

	public function write($key, $value, $duration) {

		if ($duration > 30 * DAY) {

			$duration = 0;

		}

		return $this->_Memcache->set($key, $value, $this->settings['compress'], $duration);

	}

/**

 * Read a key from the cache

 *

 * @param string $key Identifier for the data

 * @return mixed The cached data, or false if the data doesn't exist, has expired, or if there was an error fetching it

 */

	public function read($key) {

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

	}

/**

 * Increments the value of an integer cached key

 *

 * @param string $key Identifier for the data

 * @param integer $offset How much to increment

 * @return New incremented value, false otherwise

 * @throws CacheException when you try to increment with compress = true

 */

	public function increment($key, $offset = 1) {

		if ($this->settings['compress']) {

			throw new CacheException(

				__d('cake_dev', 'Method %s not implemented for compressed cache in %s', 'increment()', __CLASS__)

			);

		}

		return $this->_Memcache->increment($key, $offset);

	}

/**

 * Decrements the value of an integer cached key

 *

 * @param string $key Identifier for the data

 * @param integer $offset How much to subtract

 * @return New decremented value, false otherwise

 * @throws CacheException when you try to decrement with compress = true

 */

	public function decrement($key, $offset = 1) {

		if ($this->settings['compress']) {

			throw new CacheException(

				__d('cake_dev', 'Method %s not implemented for compressed cache in %s', 'decrement()', __CLASS__)

			);

		}

		return $this->_Memcache->decrement($key, $offset);

	}

/**

 * Delete a key from the cache

 *

 * @param string $key Identifier for the data

 * @return boolean True if the value was successfully deleted, false if it didn't exist or couldn't be removed

 */

	public function delete($key) {

		return $this->_Memcache->delete($key);

	}

/**

 * Delete all keys from the cache

 *

 * @param boolean $check

 * @return boolean True if the cache was successfully cleared, false otherwise

 */

	public function clear($check) {

		if ($check) {

			return true;

		}

		foreach ($this->_Memcache->getExtendedStats('slabs') as $slabs) {

			foreach (array_keys($slabs) as $slabId) {

				if (!is_numeric($slabId)) {

					continue;

				}

				foreach ($this->_Memcache->getExtendedStats('cachedump', $slabId) as $stats) {

					if (!is_array($stats)) {

						continue;

					}

					foreach (array_keys($stats) as $key) {

						if (strpos($key, $this->settings['prefix']) === 0) {

							$this->_Memcache->delete($key);

						}

					}

				}

			}

		}

		return true;

	}

/**

 * Connects to a server in connection pool

 *

 * @param string $host host ip address or name

 * @param integer $port Server port

 * @return boolean True if memcache server was connected

 */

	public function connect($host, $port = 11211) {

		if ($this->_Memcache->getServerStatus($host, $port) === 0) {

			if ($this->_Memcache->connect($host, $port)) {

				return true;

			}

			return false;

		}

		return true;

	}

/**

 * Returns the `group value` for each of the configured groups

 * If the group initial value was not found, then it initializes

 * the group accordingly.

 *

 * @return array

 */

	public function groups() {

		if (empty($this->_compiledGroupNames)) {

			foreach ($this->settings['groups'] as $group) {

				$this->_compiledGroupNames[] = $this->settings['prefix'] . $group;

			}

		}

		$groups = $this->_Memcache->get($this->_compiledGroupNames);

		if (count($groups) !== count($this->settings['groups'])) {

			foreach ($this->_compiledGroupNames as $group) {

				if (!isset($groups[$group])) {

					$this->_Memcache->set($group, 1, false, 0);

					$groups[$group] = 1;

				}

			}

			ksort($groups);

		}

		$result = array();

		$groups = array_values($groups);

		foreach ($this->settings['groups'] as $i => $group) {

			$result[] = $group . $groups[$i];

		}

		return $result;

	}

/**

 * Increments the group value to simulate deletion of all keys under a group

 * old values will remain in storage until they expire.

 *

 * @return boolean success

 */

	public function clearGroup($group) {

		return (bool)$this->_Memcache->increment($this->settings['prefix'] . $group);

	}

}