* @link http://www.yiiframework.com/ * @copyright Copyright © 2008-2011 Yii Software LLC * @license http://www.yiiframework.com/license/ */ /** * CMemCache implements a cache application component based on {@link http://memcached.org/ memcached}. * * CMemCache can be configured with a list of memcache servers by settings * its {@link setServers servers} property. By default, CMemCache assumes * there is a memcache server running on localhost at port 11211. * * See {@link CCache} manual for common cache operations that are supported by CMemCache. * * Note, there is no security measure to protected data in memcache. * All data in memcache can be accessed by any process running in the system. * * To use CMemCache as the cache application component, configure the application as follows, *
 * array(
 *     'components'=>array(
 *         'cache'=>array(
 *             'class'=>'CMemCache',
 *             'servers'=>array(
 *                 array(
 *                     'host'=>'server1',
 *                     'port'=>11211,
 *                     'weight'=>60,
 *                 ),
 *                 array(
 *                     'host'=>'server2',
 *                     'port'=>11211,
 *                     'weight'=>40,
 *                 ),
 *             ),
 *         ),
 *     ),
 * )
 * 
* In the above, two memcache servers are used: server1 and server2. * You can configure more properties of every server, including: * host, port, persistent, weight, timeout, retryInterval, status. * See {@link http://www.php.net/manual/en/function.memcache-addserver.php} * for more details. * * CMemCache can also be used with {@link http://pecl.php.net/package/memcached memcached}. * To do so, set {@link useMemcached} to be true. * * @property mixed $memCache The memcache instance (or memcached if {@link useMemcached} is true) used by this component. * @property array $servers List of memcache server configurations. Each element is a {@link CMemCacheServerConfiguration}. * * @author Qiang Xue * @version $Id$ * @package system.caching * @since 1.0 */ class CMemCache extends CCache { /** * @var boolean whether to use memcached or memcache as the underlying caching extension. * If true {@link http://pecl.php.net/package/memcached memcached} will be used. * If false {@link http://pecl.php.net/package/memcache memcache}. will be used. * Defaults to false. */ public $useMemcached=false; /** * @var Memcache the Memcache instance */ private $_cache=null; /** * @var array list of memcache server configurations */ private $_servers=array(); /** * Initializes this application component. * This method is required by the {@link IApplicationComponent} interface. * It creates the memcache instance and adds memcache servers. * @throws CException if memcache extension is not loaded */ public function init() { parent::init(); $servers=$this->getServers(); $cache=$this->getMemCache(); if(count($servers)) { foreach($servers as $server) { if($this->useMemcached) $cache->addServer($server->host,$server->port,$server->weight); else $cache->addServer($server->host,$server->port,$server->persistent,$server->weight,$server->timeout,$server->status); } } else $cache->addServer('localhost',11211); } /** * @throws CException if extension isn't loaded * @return Memcache|Memcached the memcache instance (or memcached if {@link useMemcached} is true) used by this component. */ public function getMemCache() { if($this->_cache!==null) return $this->_cache; else { $extension=$this->useMemcached ? 'memcached' : 'memcache'; if(!extension_loaded($extension)) throw new CException(Yii::t('yii',"CMemCache requires PHP $extension extension to be loaded.")); return $this->_cache=$this->useMemcached ? new Memcached : new Memcache; } } /** * @return array list of memcache server configurations. Each element is a {@link CMemCacheServerConfiguration}. */ public function getServers() { return $this->_servers; } /** * @param array $config list of memcache server configurations. Each element must be an array * with the following keys: host, port, persistent, weight, timeout, retryInterval, status. * @see http://www.php.net/manual/en/function.Memcache-addServer.php */ public function setServers($config) { foreach($config as $c) $this->_servers[]=new CMemCacheServerConfiguration($c); } /** * Retrieves a value from cache with a specified key. * This is the implementation of the method declared in the parent class. * @param string $key a unique key identifying the cached value * @return string the value stored in cache, false if the value is not in the cache or expired. */ protected function getValue($key) { return $this->_cache->get($key); } /** * Retrieves multiple values from cache with the specified keys. * @param array $keys a list of keys identifying the cached values * @return array a list of cached values indexed by the keys */ protected function getValues($keys) { return $this->useMemcached ? $this->_cache->getMulti($keys) : $this->_cache->get($keys); } /** * Stores a value identified by a key in cache. * This is the implementation of the method declared in the parent class. * * @param string $key the key identifying the value to be cached * @param string $value the value to be cached * @param integer $expire the number of seconds in which the cached value will expire. 0 means never expire. * @return boolean true if the value is successfully stored into cache, false otherwise */ protected function setValue($key,$value,$expire) { if($expire>0) $expire+=time(); else $expire=0; return $this->useMemcached ? $this->_cache->set($key,$value,$expire) : $this->_cache->set($key,$value,0,$expire); } /** * Stores a value identified by a key into cache if the cache does not contain this key. * This is the implementation of the method declared in the parent class. * * @param string $key the key identifying the value to be cached * @param string $value the value to be cached * @param integer $expire the number of seconds in which the cached value will expire. 0 means never expire. * @return boolean true if the value is successfully stored into cache, false otherwise */ protected function addValue($key,$value,$expire) { if($expire>0) $expire+=time(); else $expire=0; return $this->useMemcached ? $this->_cache->add($key,$value,$expire) : $this->_cache->add($key,$value,0,$expire); } /** * Deletes a value with the specified key from cache * This is the implementation of the method declared in the parent class. * @param string $key the key of the value to be deleted * @return boolean if no error happens during deletion */ protected function deleteValue($key) { return $this->_cache->delete($key, 0); } /** * Deletes all values from cache. * This is the implementation of the method declared in the parent class. * @return boolean whether the flush operation was successful. * @since 1.1.5 */ protected function flushValues() { return $this->_cache->flush(); } } /** * CMemCacheServerConfiguration represents the configuration data for a single memcache server. * * See {@link http://www.php.net/manual/en/function.Memcache-addServer.php} * for detailed explanation of each configuration property. * * @author Qiang Xue * @version $Id$ * @package system.caching * @since 1.0 */ class CMemCacheServerConfiguration extends CComponent { /** * @var string memcache server hostname or IP address */ public $host; /** * @var integer memcache server port */ public $port=11211; /** * @var boolean whether to use a persistent connection */ public $persistent=true; /** * @var integer probability of using this server among all servers. */ public $weight=1; /** * @var integer value in seconds which will be used for connecting to the server */ public $timeout=15; /** * @var integer how often a failed server will be retried (in seconds) */ public $retryInterval=15; /** * @var boolean if the server should be flagged as online upon a failure */ public $status=true; /** * Constructor. * @param array $config list of memcache server configurations. * @throws CException if the configuration is not an array */ public function __construct($config) { if(is_array($config)) { foreach($config as $key=>$value) $this->$key=$value; if($this->host===null) throw new CException(Yii::t('yii','CMemCache server configuration must have "host" value.')); } else throw new CException(Yii::t('yii','CMemCache server configuration must be an array.')); } }