From bb0f7a0f25545b067d796d2eeeecb19901abdd5f Mon Sep 17 00:00:00 2001
From: carl <>
Date: Thu, 26 Jul 2007 16:01:17 +0000
Subject: #623 - MemCache to support multiple servers
---
framework/Caching/TMemCache.php | 529 +++++++++++++++++++++++-----------------
1 file changed, 311 insertions(+), 218 deletions(-)
(limited to 'framework/Caching')
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 @@
-
- * @link http://www.pradosoft.com/
- * @copyright Copyright © 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,
- *
- * $cache=new TMemCache; // TMemCache may also be loaded as a Prado application module
- * $cache->init(null);
- * $cache->add('object',$object);
- * $object2=$cache->get('object');
- *
- *
- * 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
- *
- *
- *
- * where {@link getHost Host} and {@link getPort Port} are configurable properties
- * of TMemCache.
- *
- * @author Qiang Xue
- * @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();
- }
-}
-
+
+ * @author Carl G. Mathisen
+ * @link http://www.pradosoft.com/
+ * @copyright Copyright © 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,
+ *
+ * $cache=new TMemCache; // TMemCache may also be loaded as a Prado application module
+ * $cache->init(null);
+ * $cache->add('object',$object);
+ * $object2=$cache->get('object');
+ *
+ *
+ * You can configure TMemCache two different ways. If you only need one memcache server
+ * you may use the method as follows.
+ *
+ *
+ *
+ *
+ * If you want a more complex configuration, you may use the method as follows.
+ *
+ *
+ *
+ *
+ *
+ *
+ *
+ * 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
+ *
+ *
+ *
+ * where {@link getHost Host} and {@link getPort Port} are configurable properties
+ * of TMemCache.
+ *
+ * @author Qiang Xue
+ * @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
--
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