#623 - MemCache to support multiple servers

1 files changed, 311 insertions, 218 deletions

diff --git a/framework/Caching/TMemCache.php b/framework/Caching/TMemCache.php
index c0f9b4bc..b860db9f 100644
--- a/framework/Caching/TMemCache.php
+++ b/framework/Caching/TMemCache.php
@@ -1,219 +1,312 @@
-<?php

-/**

- * TMemCache class file

- *

- * @author Qiang Xue <qiang.xue@gmail.com>

- * @link http://www.pradosoft.com/

- * @copyright Copyright &copy; 2005 PradoSoft

- * @license http://www.pradosoft.com/license/

- * @version $Id$

- * @package System.Caching

- */

-

-/**

- * TMemCache class

- *

- * TMemCache implements a cache application module based on {@link http://www.danga.com/memcached/ memcached}.

- *

- * TMemCache can be configured with the Host and Port properties, which

- * specify the host and port of the memcache server to be used.

- * By default, they take the value 'localhost' and 11211, respectively.

- * These properties must be set before {@link init} is invoked.

- *

- * The following basic cache operations are implemented:

- * - {@link get} : retrieve the value with a key (if any) from cache

- * - {@link set} : store the value with a key into cache

- * - {@link add} : store the value only if cache does not have this key

- * - {@link delete} : delete the value with the specified key from cache

- * - {@link flush} : delete all values from cache

- *

- * Each value is associated with an expiration time. The {@link get} operation

- * ensures that any expired value will not be returned. The expiration time can

- * be specified by the number of seconds (maximum 60*60*24*30)

- * or a UNIX timestamp. A expiration time 0 represents never expire.

- *

- * By definition, cache does not ensure the existence of a value

- * even if it never expires. Cache is not meant to be an persistent storage.

- *

- * Also 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 this module, the memcache PHP extension must be loaded.

- *

- * Some usage examples of TMemCache are as follows,

- * <code>

- * $cache=new TMemCache;  // TMemCache may also be loaded as a Prado application module

- * $cache->init(null);

- * $cache->add('object',$object);

- * $object2=$cache->get('object');

- * </code>

- *

- * If loaded, TMemCache will register itself with {@link TApplication} as the

- * cache module. It can be accessed via {@link TApplication::getCache()}.

- *

- * TMemCache may be configured in application configuration file as follows

- * <code>

- * <module id="cache" class="System.Caching.TMemCache" Host="localhost" Port="11211" />

- * </code>

- * where {@link getHost Host} and {@link getPort Port} are configurable properties

- * of TMemCache.

- *

- * @author Qiang Xue <qiang.xue@gmail.com>

- * @version $Id$

- * @package System.Caching

- * @since 3.0

- */

-class TMemCache extends TCache

-{

-	/**

-	 * @var boolean if the module is initialized

-	 */

-	private $_initialized=false;

-	/**

-	 * @var Memcache the Memcache instance

-	 */

-	private $_cache=null;

-	/**

-	 * @var string a unique prefix used to identify this cache instance from the others

-	 */

-	private $_prefix=null;

-	/**

-	 * @var string host name of the memcache server

-	 */

-	private $_host='localhost';

-	/**

-	 * @var integer the port number of the memcache server

-	 */

-	private $_port=11211;

-

-	/**

-	 * Destructor.

-	 * Disconnect the memcache server.

-	 */

-	public function __destruct()

-	{

-		if($this->_cache!==null)

-			$this->_cache->close();

-	}

-

-	/**

-	 * Initializes this module.

-	 * This method is required by the IModule interface. It makes sure that

-	 * UniquePrefix has been set, creates a Memcache instance and connects

-	 * to the memcache server.

-	 * @param TApplication Prado application, can be null

-	 * @param TXmlElement configuration for this module, can be null

-	 * @throws TConfigurationException if memcache extension is not installed or memcache sever connection fails

-	 */

-	public function init($config)

-	{

-		if(!extension_loaded('memcache'))

-			throw new TConfigurationException('memcache_extension_required');

-		$this->_cache=new Memcache;

-		if($this->_cache->connect($this->_host,$this->_port)===false)

-			throw new TConfigurationException('memcache_connection_failed',$this->_host,$this->_port);

-		$this->_initialized=true;

-		parent::init($config);

-	}

-

-	/**

-	 * @return string host name of the memcache server

-	 */

-	public function getHost()

-	{

-		return $this->_host;

-	}

-

-	/**

-	 * @param string host name of the memcache server

-	 * @throws TInvalidOperationException if the module is already initialized

-	 */

-	public function setHost($value)

-	{

-		if($this->_initialized)

-			throw new TInvalidOperationException('memcache_host_unchangeable');

-		else

-			$this->_host=$value;

-	}

-

-	/**

-	 * @return integer port number of the memcache server

-	 */

-	public function getPort()

-	{

-		return $this->_port;

-	}

-

-	/**

-	 * @param integer port number of the memcache server

-	 * @throws TInvalidOperationException if the module is already initialized

-	 */

-	public function setPort($value)

-	{

-		if($this->_initialized)

-			throw new TInvalidOperationException('memcache_port_unchangeable');

-		else

-			$this->_port=TPropertyValue::ensureInteger($value);

-	}

-

-	/**

-	 * Retrieves a value from cache with a specified key.

-	 * This is the implementation of the method declared in the parent class.

-	 * @param string 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);

-	}

-

-	/**

-	 * Stores a value identified by a key in cache.

-	 * This is the implementation of the method declared in the parent class.

-	 *

-	 * @param string the key identifying the value to be cached

-	 * @param string the value to be cached

-	 * @param integer 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)

-	{

-		return $this->_cache->set($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 the key identifying the value to be cached

-	 * @param string the value to be cached

-	 * @param integer 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)

-	{

-		return $this->_cache->add($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 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);

-	}

-

-	/**

-	 * Deletes all values from cache.

-	 * Be careful of performing this operation if the cache is shared by multiple applications.

-	 */

-	public function flush()

-	{

-		return $this->_cache->flush();

-	}

-}

-

+<?php
+/**
+ * TMemCache class file
+ *
+ * @author Qiang Xue <qiang.xue@gmail.com>
+ * @author Carl G. Mathisen <carlgmathisen@gmail.com>
+ * @link http://www.pradosoft.com/
+ * @copyright Copyright &copy; 2005 PradoSoft
+ * @license http://www.pradosoft.com/license/
+ * @version $Id$
+ * @package System.Caching
+ */
+
+/**
+ * TMemCache class
+ *
+ * TMemCache implements a cache application module based on {@link http://www.danga.com/memcached/ memcached}.
+ *
+ * TMemCache can be configured with the Host and Port properties, which
+ * specify the host and port of the memcache server to be used.
+ * By default, they take the value 'localhost' and 11211, respectively.
+ * These properties must be set before {@link init} is invoked.
+ *
+ * The following basic cache operations are implemented:
+ * - {@link get} : retrieve the value with a key (if any) from cache
+ * - {@link set} : store the value with a key into cache
+ * - {@link add} : store the value only if cache does not have this key
+ * - {@link delete} : delete the value with the specified key from cache
+ * - {@link flush} : delete all values from cache
+ *
+ * Each value is associated with an expiration time. The {@link get} operation
+ * ensures that any expired value will not be returned. The expiration time can
+ * be specified by the number of seconds (maximum 60*60*24*30)
+ * or a UNIX timestamp. A expiration time 0 represents never expire.
+ *
+ * By definition, cache does not ensure the existence of a value
+ * even if it never expires. Cache is not meant to be an persistent storage.
+ *
+ * Also 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 this module, the memcache PHP extension must be loaded.
+ *
+ * Some usage examples of TMemCache are as follows,
+ * <code>
+ * $cache=new TMemCache;  // TMemCache may also be loaded as a Prado application module
+ * $cache->init(null);
+ * $cache->add('object',$object);
+ * $object2=$cache->get('object');
+ * </code>
+ *
+ * You can configure TMemCache two different ways. If you only need one memcache server
+ * you may use the method as follows.
+ * <code>
+ * <module id="cache" class="System.Caching.TMemCache" Host="localhost" Port="11211" />
+ * </code>
+ *
+ * If you want a more complex configuration, you may use the method as follows.
+ * <code>
+ * <module id="cache" classs="System.Caching.TMemCache">
+ *     <server Host="localhost" Port="11211" Weight="1" Timeout="300" RetryInterval="15" />
+ *     <server Host="anotherhost" Port="11211" Weight="1" Timeout="300" RetryInterval="15" />
+ * </module>
+ * </code>
+ *
+ * If loaded, TMemCache will register itself with {@link TApplication} as the
+ * cache module. It can be accessed via {@link TApplication::getCache()}.
+ *
+ * TMemCache may be configured in application configuration file as follows
+ * <code>
+ * <module id="cache" class="System.Caching.TMemCache" Host="localhost" Port="11211" />
+ * </code>
+ * where {@link getHost Host} and {@link getPort Port} are configurable properties
+ * of TMemCache.
+ *
+ * @author Qiang Xue <qiang.xue@gmail.com>
+ * @version $Id$
+ * @package System.Caching
+ * @since 3.0
+ */
+class TMemCache extends TCache
+{
+	/**
+	 * @var boolean if the module is initialized
+	 */
+	private $_initialized=false;
+	/**
+	 * @var Memcache the Memcache instance
+	 */
+	private $_cache=null;
+	/**
+	 * @var string a unique prefix used to identify this cache instance from the others
+	 */
+	private $_prefix=null;
+	/**
+	 * @var string host name of the memcache server
+	 */
+	private $_host='localhost';
+	/**
+	 * @var integer the port number of the memcache server
+	 */
+	private $_port=11211;
+	/**
+	 * @var boolean controls the use of a persistent connection. Default to true.
+	 */
+    private $_persistence = true;
+    /**
+     * @var integer number of buckets to create for this server which in turn control its
+     * probability of it being selected. The probability is relative to the total weight 
+     * of all servers.
+     */
+    private $_weight = 1;
+    
+    private $_timeout = 360;
+
+    private $_retryInterval = 15;
+    
+    private $_status = true;
+    
+    private $_failureCallback = null;
+
+	/**
+	 * @var array list of servers available
+	 */
+	private $_servers=array();
+
+	/**
+	 * Destructor.
+	 * Disconnect the memcache server.
+	 */
+	public function __destruct()
+	{
+		if($this->_cache!==null)
+			$this->_cache->close();
+	}
+
+	/**
+	 * Initializes this module.
+	 * This method is required by the IModule interface. It makes sure that
+	 * UniquePrefix has been set, creates a Memcache instance and connects
+	 * to the memcache server.
+	 * @param TApplication Prado application, can be null
+	 * @param TXmlElement configuration for this module, can be null
+	 * @throws TConfigurationException if memcache extension is not installed or memcache sever connection fails
+	 */
+	public function init($config)
+	{
+		if(!extension_loaded('memcache'))
+			throw new TConfigurationException('memcache_extension_required');
+		$this->_cache=new Memcache;
+		$this->loadConfig($config);
+		if(count($this->_servers))
+        {
+            foreach($this->_servers as $server)
+            {
+                Prado::trace('Adding server '.$server['Host'].' from serverlist', 'System.Caching.TMemCache');
+                if($this->_cache->addServer($server['Host'],$server['Port'],$server['Persistent'],
+                    $server['Weight'],$server['Timeout'],$server['RetryInterval'])===false)
+                    throw new TConfigurationException('memcache_connection_failed',$server['Host'],$server['Port']);
+            }
+        }
+        else
+        {
+            Prado::trace('Adding server '.$this->_host, 'System.Caching.TMemCache');
+            if($this->_cache->addServer($this->_host,$this->_port)===false)
+                throw new TConfigurationException('memcache_connection_failed',$this->_host,$this->_port);
+        }	
+		//if($this->_cache->connect($this->_host,$this->_port)===false)
+		//	throw new TConfigurationException('memcache_connection_failed',$this->_host,$this->_port);
+		$this->_initialized=true;
+		parent::init($config);
+	}
+	
+    /**
+	 * Loads configuration from an XML element
+	 * @param TXmlElement configuration node
+	 * @throws TConfigurationException if log route class or type is not specified
+	 */
+	private function loadConfig($xml)
+	{
+	    if($xml instanceof TXmlElement)
+		{
+    		foreach($xml->getElementsByTagName('server') as $serverConfig)
+    		{
+    			$properties=$serverConfig->getAttributes();
+    			if(($host=$properties->remove('Host'))===null)
+    				throw new TConfigurationException('memcache_serverhost_required');
+    			if(($port=$properties->remove('Port'))===null)
+        			throw new TConfigurationException('memcache_serverport_required');
+        		if(!is_numeric($port))
+        		    throw new TConfigurationException('memcache_serverport_invalid');
+        		$server = array('Host'=>$host,'Port'=>$port,'Weight'=>1,'Timeout'=>1800,'RetryInterval'=>15,'Persistent'=>true);
+        		$checks = array(
+        		    'Weight'=>'memcache_serverweight_invalid',
+        		    'Timeout'=>'memcache_servertimeout_invalid',
+        		    'RetryInterval'=>'memcach_serverretryinterval_invalid'
+        		);
+        		foreach($checks as $property=>$exception)
+        		{
+        		    $value=$properties->remove($property); 
+        		    if($value!==null && is_numeric($value))
+        		        $server[$property]=$value;
+        		    else if($value!==null)
+        		        throw new TConfigurationException($exception);
+        		}
+        		$server['Persistent']= TPropertyValue::ensureBoolean($properties->remove('Persistent'));
+    			$this->_servers[]=$server;
+    		}
+	    }
+	}
+
+	/**
+	 * @return string host name of the memcache server
+	 */
+	public function getHost()
+	{
+		return $this->_host;
+	}
+
+	/**
+	 * @param string host name of the memcache server
+	 * @throws TInvalidOperationException if the module is already initialized
+	 */
+	public function setHost($value)
+	{
+		if($this->_initialized)
+			throw new TInvalidOperationException('memcache_host_unchangeable');
+		else
+			$this->_host=$value;
+	}
+
+	/**
+	 * @return integer port number of the memcache server
+	 */
+	public function getPort()
+	{
+		return $this->_port;
+	}
+
+	/**
+	 * @param integer port number of the memcache server
+	 * @throws TInvalidOperationException if the module is already initialized
+	 */
+	public function setPort($value)
+	{
+		if($this->_initialized)
+			throw new TInvalidOperationException('memcache_port_unchangeable');
+		else
+			$this->_port=TPropertyValue::ensureInteger($value);
+	}
+
+	/**
+	 * Retrieves a value from cache with a specified key.
+	 * This is the implementation of the method declared in the parent class.
+	 * @param string 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);
+	}
+
+	/**
+	 * Stores a value identified by a key in cache.
+	 * This is the implementation of the method declared in the parent class.
+	 *
+	 * @param string the key identifying the value to be cached
+	 * @param string the value to be cached
+	 * @param integer 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)
+	{
+		return $this->_cache->set($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 the key identifying the value to be cached
+	 * @param string the value to be cached
+	 * @param integer 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)
+	{
+		return $this->_cache->add($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 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);
+	}
+
+	/**
+	 * Deletes all values from cache.
+	 * Be careful of performing this operation if the cache is shared by multiple applications.
+	 */
+	public function flush()
+	{
+		return $this->_cache->flush();
+	}
+}
+
 ?>
\ No newline at end of file