add MemcachedEngine

Lib/Cache/Engine/MemcachedEngine.php

@@ -0,0 +1,258 @@
+<?php
+/**
+ * Memcached storage engine for cache
+ *
+ *
+ * PHP 5
+ *
+ * CakePHP(tm) : Rapid Development Framework (http://cakephp.org)
+ * Copyright 2005-2012, Cake Software Foundation, Inc. (http://cakefoundation.org)
+ *
+ * Licensed under The MIT License
+ * Redistributions of files must retain the above copyright notice.
+ *
+ * @copyright     Copyright 2005-2012, 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       MIT License (http://www.opensource.org/licenses/mit-license.php)
+ */
+
+/**
+ * Memcached storage engine for cache. This is the new more powerful memcache class (see MemcacheEngine for the former one).
+ *
+ * @package       Cake.Cache.Engine
+ */
+class MemcachedEngine extends CacheEngine {
+
+/**
+ * Contains the compiled group names
+ * (prefixed witht the global configuration prefix)
+ *
+ * @var array
+ **/
+	protected $_compiledGroupNames = array();
+
+/**
+ * Memcache wrapper.
+ *
+ * @var Memcache
+ */
+	protected $_Memcached = null;
+
+/**
+ * Settings
+ *
+ *  - servers = string or array of memcache servers, default => 127.0.0.1. If an
+ *    array MemcacheEngine will use them as a pool.
+ *
+ * @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('Memcached')) {
+			return false;
+		}
+		if (!isset($settings['prefix'])) {
+			$settings['prefix'] = Inflector::slug(APP_DIR) . '_';
+		}
+		$settings += array(
+			'engine' => 'Memcached',
+			'servers' => array('127.0.0.1'),
+			'compress' => false,
+			'persistent' => true
+		);
+		parent::init($settings);
+
+		if (is_string($this->settings['servers'])) {
+			$this->settings['servers'] = array($this->settings['servers']);
+		}
+		if (!isset($this->_Memcached)) {
+			$return = false;
+			$this->_Memcached = new Memcached();
+			foreach ($this->settings['servers'] as $server) {
+				list($host, $port) = $this->_parseServerString($server);
+				if ($this->_Memcached->addServer($host, $port)) {
+					$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 $this->_Memcached->set($key, $value, $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 $this->_Memcached->get($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) {
+		return $this->_Memcached->increment($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) {
+		return $this->_Memcached->decrement($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 $this->_Memcached->delete($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->_Memcached->getExtendedStats('slabs') as $slabs) {
+			foreach (array_keys($slabs) as $slabId) {
+				if (!is_numeric($slabId)) {
+					continue;
+				}
+
+				foreach ($this->_Memcached->getExtendedStats('cachedump', $slabId) as $stats) {
+					if (!is_array($stats)) {
+						continue;
+					}
+					foreach (array_keys($stats) as $key) {
+						if (strpos($key, $this->settings['prefix']) === 0) {
+							$this->_Memcached->delete($key);
+						}
+					}
+				}
+			}
+		}
+		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 = $this->_Memcached->get($this->_compiledGroupNames);
+		if (count($groups) !== count($this->settings['groups'])) {
+			foreach ($this->_compiledGroupNames as $group) {
+				if (!isset($groups[$group])) {
+					$this->_Memcached->set($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)$this->_Memcached->increment($this->settings['prefix'] . $group);
+	}
+}