Caching provider for memcached using PHP's memcache extension

phpgwapi/inc/class.egw_cache.inc.php

@@ -68,7 +68,7 @@ class egw_cache
 	 *
 	 * @var array
 	 */
-	static $default_provider = array('egw_cache_files');// array('egw_cache_memcache','localhost',11211);
+	static $default_provider = array('egw_cache_files');// array('egw_cache_memcache','localhost');
 
 	/**
 	 * Set some data in the cache

phpgwapi/inc/class.egw_cache_memcache.inc.php

@@ -0,0 +1,119 @@
+<?php
+/**
+ * eGroupWare API: Caching provider storing data in memcached via PHP's memcache extension
+ *
+ * @link http://www.egroupware.org
+ * @license http://opensource.org/licenses/gpl-license.php GPL - GNU General Public License
+ * @package api
+ * @subpackage cache
+ * @author Ralf Becker <RalfBecker-AT-outdoor-training.de>
+ * @copyright (c) 2009 by Ralf Becker <RalfBecker-AT-outdoor-training.de>
+ * @version $Id$
+ */
+
+/**
+ * Caching provider storing data in memcached via PHP's memcache extension
+ *
+ * The provider concats all $keys with '::' to get a single string.
+ *
+ * To use this provider set in your header.inc.php:
+ * $GLOBALS['egw_info']['server']['cache_provider_instance'] = array('egw_cache_memcache','localhost'[,'otherhost:port']);
+ * and optional also $GLOBALS['egw_info']['server']['cache_provider_tree'] (defaults to instance)
+ *
+ * You can set more then one server and specify a port, if it's not the default one 11211.
+ */
+class egw_cache_memcache implements egw_cache_provider
+{
+	/**
+	 * Instance of Memcache
+	 *
+	 * @var Memcache
+	 */
+	private $memcache;
+
+	/**
+	 * Flags used to store content
+	 *
+	 */
+	const STORE_FLAGS = MEMCACHE_COMPRESSED;
+
+	/**
+	 * Constructor, eg. opens the connection to the backend
+	 *
+	 * @throws Exception if connection to backend could not be established
+	 * @param array $params eg. array('localhost'[,'localhost:11211',...])
+	 */
+	function __construct(array $params)
+	{
+		check_load_extension('memcache',true);
+		$this->memcache = new Memcache();
+
+		if (!$params) $params = array('localhost');	// some reasonable default
+
+		$ok = false;
+		foreach($params as $host_port)
+		{
+			list($host,$port) = explode(':',$host_port);
+			if (!$port) $port = 11211;	// default port
+
+			$ok = $this->memcache->addServer($host,$port) || $ok;
+			//error_log(__METHOD__."(".array2string($params).") memcache->addServer('$host',$port) = ".(int)$ok);
+		}
+		if (!$ok)
+		{
+			throw new Exception (__METHOD__.'('.array2string($params).") Can't open connection to any memcached server!");
+		}
+	}
+
+	/**
+	 * Stores some data in the cache
+	 *
+	 * @param array $keys eg. array($level,$app,$location)
+	 * @param mixed $data
+	 * @param int $expiration=0
+	 * @return boolean true on success, false on error
+	 */
+	function set(array $keys,$data,$expiration=0)
+	{
+		return $this->memcache->set(self::key($keys),serialize($data),self::STORE_FLAGS,$expiration);
+	}
+
+	/**
+	 * Get some data from the cache
+	 *
+	 * @param array $keys eg. array($level,$app,$location)
+	 * @return mixed data stored or NULL if not found in cache
+	 */
+	function get(array $keys)
+	{
+		if (($data = $this->memcache->get($key=self::key($keys))) === false)
+		{
+			//error_log(__METHOD__."(".array2string($keys).") key='$key' NOT found!");
+			return null;
+		}
+		//error_log(__METHOD__."(".array2string($keys).") key='$key' found ".bytes($data)." bytes).");
+		return unserialize($data);
+	}
+
+	/**
+	 * Delete some data from the cache
+	 *
+	 * @param array $keys eg. array($level,$app,$location)
+	 * @return boolean true on success, false on error (eg. $key not set)
+	 */
+	function delete(array $keys)
+	{
+		return $this->memcache->delete(self::key($keys));
+	}
+
+	/**
+	 * Create a single key from $keys
+	 *
+	 * @param array $keys
+	 * @return string
+	 */
+	private function key(array $keys)
+	{
+		return implode('::',$keys);
+	}
+}