array( * 'cache'=>array( * 'class'=>'MemCache', * '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 * each server, such as `persistent`, `weight`, `timeout`. Please see [[MemCacheServer]] for available options. * * @property \Memcache|\Memcached $memCache The memcache instance (or memcached if [[useMemcached]] is true) used by this component. * @property MemCacheServer[] $servers List of memcache server configurations. * * @author Qiang Xue * @since 2.0 */ class MemCache extends Cache { /** * @var boolean whether to use memcached or memcache as the underlying caching extension. * If true, [memcached](http://pecl.php.net/package/memcached) will be used. * If false, [memcache](http://pecl.php.net/package/memcache) will be used. * Defaults to false. */ public $useMemcached = false; /** * @var \Memcache|\Memcached the Memcache instance */ private $_cache = null; /** * @var array list of memcache server configurations */ private $_servers = array(); /** * Initializes this application component. * It creates the memcache instance and adds memcache servers. */ public function init() { parent::init(); $servers = $this->getServers(); $cache = $this->getMemCache(); if (count($servers)) { foreach ($servers as $server) { if ($server->host === null) { throw new Exception("The 'host' property must be specified for every memcache 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->retryInterval, $server->status); } } } else { $cache->addServer('127.0.0.1', 11211); } } /** * Returns the underlying memcache (or memcached) object. * @return \Memcache|\Memcached the memcache (or memcached) object used by this cache component. * @throws Exception if memcache or memcached extension is not loaded */ public function getMemCache() { if ($this->_cache === null) { $extension = $this->useMemcached ? 'memcached' : 'memcache'; if (!extension_loaded($extension)) { throw new Exception("MemCache requires PHP $extension extension to be loaded."); } $this->_cache = $this->useMemcached ? new \Memcached : new \Memcache; } return $this->_cache; } /** * Returns the memcache server configurations. * @return MemCacheServer[] list of memcache server configurations. */ 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) { $this->_servers[] = new MemCacheServer($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. */ protected function flushValues() { return $this->_cache->flush(); } }