* Prado 3.3.0

7 files changed, 2164 insertions, 0 deletions

diff --git a/lib/prado/framework/Caching/TAPCCache.php b/lib/prado/framework/Caching/TAPCCache.php
new file mode 100644
index 0000000..2274412
--- /dev/null
+++ b/lib/prado/framework/Caching/TAPCCache.php
@@ -0,0 +1,127 @@
+<?php
+/**
+ * TAPCCache class file
+ *
+ * @author Alban Hanry <compte_messagerie@hotmail.com>
+ * @link https://github.com/pradosoft/prado
+ * @copyright Copyright &copy; 2005-2015 The PRADO Group
+ * @license https://github.com/pradosoft/prado/blob/master/COPYRIGHT
+ * @package System.Caching
+ */
+
+/**
+ * TAPCCache class
+ *
+ * TAPCCache implements a cache application module based on {@link http://www.php.net/apc APC}.
+ *
+ * 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.
+ *
+ * To use this module, the APC PHP extension must be loaded and set in the php.ini file the following:
+ * <code>
+ * apc.cache_by_default=0
+ * </code>
+ *
+ * Some usage examples of TAPCCache are as follows,
+ * <code>
+ * $cache=new TAPCCache;  // TAPCCache may also be loaded as a Prado application module
+ * $cache->init(null);
+ * $cache->add('object',$object);
+ * $object2=$cache->get('object');
+ * </code>
+ *
+ * If loaded, TAPCCache will register itself with {@link TApplication} as the
+ * cache module. It can be accessed via {@link TApplication::getCache()}.
+ *
+ * TAPCCache may be configured in application configuration file as follows
+ * <code>
+ * <module id="cache" class="System.Caching.TAPCCache" />
+ * </code>
+ *
+ * @author Alban Hanry <compte_messagerie@hotmail.com>
+ * @author Knut Urdalen <knut.urdalen@gmail.com>
+ * @package System.Caching
+ * @since 3.0b
+ */
+class TAPCCache extends TCache
+{
+   /**
+    * Initializes this module.
+    * This method is required by the IModule interface.
+    * @param TXmlElement configuration for this module, can be null
+    * @throws TConfigurationException if apc extension is not installed or not started, check your php.ini
+    */
+	public function init($config)
+	{
+		if(!extension_loaded('apc'))
+			throw new TConfigurationException('apccache_extension_required');
+
+		if(ini_get('apc.enabled') == false)
+			throw new TConfigurationException('apccache_extension_not_enabled');
+
+		if(substr(php_sapi_name(), 0, 3) === 'cli' and ini_get('apc.enable_cli') == false)
+			throw new TConfigurationException('apccache_extension_not_enabled_cli');
+
+		parent::init($config);
+	}
+
+	/**
+	 * 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($key)
+	{
+		return apc_fetch($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,$expire)
+	{
+		return apc_store($key,$value,$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,$expire)
+	{
+		return apc_add($key,$value,$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($key)
+	{
+		return apc_delete($key);
+	}
+
+	/**
+	 * Deletes all values from cache.
+	 * Be careful of performing this operation if the cache is shared by multiple applications.
+	 */
+	public function flush()
+	{
+		return apc_clear_cache('user');
+	}
+}
+
diff --git a/lib/prado/framework/Caching/TCache.php b/lib/prado/framework/Caching/TCache.php
new file mode 100644
index 0000000..4a66dd0
--- /dev/null
+++ b/lib/prado/framework/Caching/TCache.php
@@ -0,0 +1,710 @@
+<?php
+/**
+ * TCache and cache dependency classes.
+ *
+ * @author Qiang Xue <qiang.xue@gmail.com>
+ * @link https://github.com/pradosoft/prado
+ * @copyright Copyright &copy; 2005-2015 The PRADO Group
+ * @license https://github.com/pradosoft/prado/blob/master/COPYRIGHT
+ * @package System.Caching
+ */
+
+Prado::using('System.Collections.TList');
+
+/**
+ * TCache class
+ *
+ * TCache is the base class for cache classes with different cache storage implementation.
+ *
+ * TCache implements the interface {@link ICache} with the following methods,
+ * - {@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 by
+ * the number of seconds. 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.
+ *
+ * Child classes must implement the following methods:
+ * - {@link getValue}
+ * - {@link setValue}
+ * - {@link addValue}
+ * - {@link deleteValue}
+ * and optionally {@link flush}
+ *
+ * Since version 3.1.2, TCache implements the ArrayAccess interface such that
+ * the cache acts as an array.
+ *
+ * @author Qiang Xue <qiang.xue@gmail.com>
+ * @package System.Caching
+ * @since 3.0
+ */
+abstract class TCache extends TModule implements ICache, ArrayAccess
+{
+	private $_prefix=null;
+	private $_primary=true;
+
+	/**
+	 * Initializes the cache module.
+	 * This method initializes the cache key prefix and registers the cache module
+	 * with the application if the cache is primary.
+	 * @param TXmlElement the module configuration
+	 */
+	public function init($config)
+	{
+		if($this->_prefix===null)
+			$this->_prefix=$this->getApplication()->getUniqueID();
+		if($this->_primary)
+		{
+			if($this->getApplication()->getCache()===null)
+				$this->getApplication()->setCache($this);
+			else
+				throw new TConfigurationException('cache_primary_duplicated',get_class($this));
+		}
+	}
+
+	/**
+	 * @return boolean whether this cache module is used as primary/system cache.
+	 * A primary cache is used by PRADO core framework to cache data such as
+	 * parsed templates, themes, etc.
+	 */
+	public function getPrimaryCache()
+	{
+		return $this->_primary;
+	}
+
+	/**
+	 * @param boolean whether this cache module is used as primary/system cache. Defaults to false.
+	 * @see getPrimaryCache
+	 */
+	public function setPrimaryCache($value)
+	{
+		$this->_primary=TPropertyValue::ensureBoolean($value);
+	}
+
+	/**
+	 * @return string a unique prefix for the keys of cached values.
+	 * If it is not explicitly set, it will take the value of {@link TApplication::getUniqueID}.
+	 */
+	public function getKeyPrefix()
+	{
+		return $this->_prefix;
+	}
+
+	/**
+	 * @param string a unique prefix for the keys of cached values
+	 */
+	public function setKeyPrefix($value)
+	{
+		$this->_prefix=$value;
+	}
+
+	/**
+	 * @param string a key identifying a value to be cached
+	 * @return sring a key generated from the provided key which ensures the uniqueness across applications
+	 */
+	protected function generateUniqueKey($key)
+	{
+		return md5($this->_prefix.$key);
+	}
+
+	/**
+	 * Retrieves a value from cache with a specified key.
+	 * @param string a key identifying the cached value
+	 * @return mixed the value stored in cache, false if the value is not in the cache or expired.
+	 */
+	public function get($id)
+	{
+		if(($data=$this->getValue($this->generateUniqueKey($id)))!==false)
+		{
+			if(!is_array($data))
+				return false;
+			if(!($data[1] instanceof ICacheDependency) || !$data[1]->getHasChanged())
+				return $data[0];
+		}
+		return false;
+	}
+
+	/**
+	 * Stores a value identified by a key into cache.
+	 * If the cache already contains such a key, the existing value and
+	 * expiration time will be replaced with the new ones. If the value is
+	 * empty, the cache key will be deleted.
+	 *
+	 * @param string the key identifying the value to be cached
+	 * @param mixed the value to be cached
+	 * @param integer the number of seconds in which the cached value will expire. 0 means never expire.
+	 * @param ICacheDependency dependency of the cached item. If the dependency changes, the item is labeled invalid.
+	 * @return boolean true if the value is successfully stored into cache, false otherwise
+	 */
+	public function set($id,$value,$expire=0,$dependency=null)
+	{
+		if(empty($value) && $expire === 0)
+			$this->delete($id);
+		else
+		{
+			$data=array($value,$dependency);
+			return $this->setValue($this->generateUniqueKey($id),$data,$expire);
+		}
+	}
+
+	/**
+	 * Stores a value identified by a key into cache if the cache does not contain this key.
+	 * Nothing will be done if the cache already contains the key or if value is empty.
+	 * @param string the key identifying the value to be cached
+	 * @param mixed the value to be cached
+	 * @param integer the number of seconds in which the cached value will expire. 0 means never expire.
+	 * @param ICacheDependency dependency of the cached item. If the dependency changes, the item is labeled invalid.
+	 * @return boolean true if the value is successfully stored into cache, false otherwise
+	 */
+	public function add($id,$value,$expire=0,$dependency=null)
+	{
+		if(empty($value) && $expire === 0)
+			return false;
+		$data=array($value,$dependency);
+		return $this->addValue($this->generateUniqueKey($id),$data,$expire);
+	}
+
+	/**
+	 * Deletes a value with the specified key from cache
+	 * @param string the key of the value to be deleted
+	 * @return boolean if no error happens during deletion
+	 */
+	public function delete($id)
+	{
+		return $this->deleteValue($this->generateUniqueKey($id));
+	}
+
+	/**
+	 * Deletes all values from cache.
+	 * Be careful of performing this operation if the cache is shared by multiple applications.
+	 * Child classes may implement this method to realize the flush operation.
+	 * @throws TNotSupportedException if this method is not overridden by child classes
+	 */
+	public function flush()
+	{
+		throw new TNotSupportedException('cache_flush_unsupported');
+	}
+
+	/**
+	 * Retrieves a value from cache with a specified key.
+	 * This method should be implemented by child classes to store the data
+	 * in specific cache storage. The uniqueness and dependency are handled
+	 * in {@link get()} already. So only the implementation of data retrieval
+	 * is needed.
+	 * @param string a unique key identifying the cached value
+	 * @return string the value stored in cache, false if the value is not in the cache or expired.
+	 */
+	abstract protected function getValue($key);
+
+	/**
+	 * Stores a value identified by a key in cache.
+	 * This method should be implemented by child classes to store the data
+	 * in specific cache storage. The uniqueness and dependency are handled
+	 * in {@link set()} already. So only the implementation of data storage
+	 * is needed.
+	 *
+	 * @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
+	 */
+	abstract protected function setValue($key,$value,$expire);
+
+	/**
+	 * Stores a value identified by a key into cache if the cache does not contain this key.
+	 * This method should be implemented by child classes to store the data
+	 * in specific cache storage. The uniqueness and dependency are handled
+	 * in {@link add()} already. So only the implementation of data storage
+	 * is needed.
+	 *
+	 * @param string the key identifying the value to be cached
+	 * @param string the value to be cached
+	 * @param integer the number of seconds in which the cached value will expire. 0 means never expire.
+	 * @return boolean true if the value is successfully stored into cache, false otherwise
+	 */
+	abstract protected function addValue($key,$value,$expire);
+
+	/**
+	 * Deletes a value with the specified key from cache
+	 * This method should be implemented by child classes to delete the data from actual cache storage.
+	 * @param string the key of the value to be deleted
+	 * @return boolean if no error happens during deletion
+	 */
+	abstract protected function deleteValue($key);
+
+	/**
+	 * Returns whether there is a cache entry with a specified key.
+	 * This method is required by the interface ArrayAccess.
+	 * @param string a key identifying the cached value
+	 * @return boolean
+	 */
+	public function offsetExists($id)
+	{
+		return $this->get($id) !== false;
+	}
+
+	/**
+	 * Retrieves the value from cache with a specified key.
+	 * This method is required by the interface ArrayAccess.
+	 * @param string a key identifying the cached value
+	 * @return mixed the value stored in cache, false if the value is not in the cache or expired.
+	 */
+	public function offsetGet($id)
+	{
+		return $this->get($id);
+	}
+
+	/**
+	 * Stores the value identified by a key into cache.
+	 * If the cache already contains such a key, the existing value will be
+	 * replaced with the new ones. To add expiration and dependencies, use the set() method.
+	 * This method is required by the interface ArrayAccess.
+	 * @param string the key identifying the value to be cached
+	 * @param mixed the value to be cached
+	 */
+	public function offsetSet($id, $value)
+	{
+		$this->set($id, $value);
+	}
+
+	/**
+	 * Deletes the value with the specified key from cache
+	 * This method is required by the interface ArrayAccess.
+	 * @param string the key of the value to be deleted
+	 * @return boolean if no error happens during deletion
+	 */
+	public function offsetUnset($id)
+	{
+		$this->delete($id);
+	}
+}
+
+
+/**
+ * TCacheDependency class.
+ *
+ * TCacheDependency is the base class implementing {@link ICacheDependency} interface.
+ * Descendant classes must implement {@link getHasChanged()} to provide
+ * actual dependency checking logic.
+ *
+ * The property value of {@link getHasChanged HasChanged} tells whether
+ * the dependency is changed or not.
+ *
+ * You may disable the dependency checking by setting {@link setEnabled Enabled}
+ * to false.
+ *
+ * Note, since the dependency objects often need to be serialized so that
+ * they can persist across requests, you may need to implement __sleep() and
+ * __wakeup() if the dependency objects contain resource handles which are
+ * not serializable.
+ *
+ * Currently, the following dependency classes are provided in the PRADO release:
+ * - {@link TFileCacheDependency}: checks whether a file is changed or not
+ * - {@link TDirectoryCacheDependency}: checks whether a directory is changed or not
+ * - {@link TGlobalStateCacheDependency}: checks whether a global state is changed or not
+ * - {@link TChainedCacheDependency}: checks whether any of a list of dependencies is changed or not
+ *
+ * @author Qiang Xue <qiang.xue@gmail.com>
+ * @package System.Caching
+ * @since 3.1.0
+ */
+abstract class TCacheDependency extends TComponent implements ICacheDependency
+{
+}
+
+
+/**
+ * TFileCacheDependency class.
+ *
+ * TFileCacheDependency performs dependency checking based on the
+ * last modification time of the file specified via {@link setFileName FileName}.
+ * The dependency is reported as unchanged if and only if the file's
+ * last modification time remains unchanged.
+ *
+ * @author Qiang Xue <qiang.xue@gmail.com>
+ * @package System.Caching
+ * @since 3.1.0
+ */
+class TFileCacheDependency extends TCacheDependency
+{
+	private $_fileName;
+	private $_timestamp;
+
+	/**
+	 * Constructor.
+	 * @param string name of the file whose change is to be checked.
+	 */
+	public function __construct($fileName)
+	{
+		$this->setFileName($fileName);
+	}
+
+	/**
+	 * @return string the name of the file whose change is to be checked
+	 */
+	public function getFileName()
+	{
+		return $this->_fileName;
+	}
+
+	/**
+	 * @param string the name of the file whose change is to be checked
+	 */
+	public function setFileName($value)
+	{
+		$this->_fileName=$value;
+		$this->_timestamp=@filemtime($value);
+	}
+
+	/**
+	 * @return int the last modification time of the file
+	 */
+	public function getTimestamp()
+	{
+		return $this->_timestamp;
+	}
+
+	/**
+	 * Performs the actual dependency checking.
+	 * This method returns true if the last modification time of the file is changed.
+	 * @return boolean whether the dependency is changed or not.
+	 */
+	public function getHasChanged()
+	{
+		return @filemtime($this->_fileName)!==$this->_timestamp;
+	}
+}
+
+/**
+ * TDirectoryCacheDependency class.
+ *
+ * TDirectoryCacheDependency performs dependency checking based on the
+ * modification time of the files contained in the specified directory.
+ * The directory being checked is specified via {@link setDirectory Directory}.
+ *
+ * By default, all files under the specified directory and subdirectories
+ * will be checked. If the last modification time of any of them is changed
+ * or if different number of files are contained in a directory, the dependency
+ * is reported as changed. By specifying {@link setRecursiveCheck RecursiveCheck}
+ * and {@link setRecursiveLevel RecursiveLevel}, one can limit the checking
+ * to a certain depth of the subdirectories.
+ *
+ * @author Qiang Xue <qiang.xue@gmail.com>
+ * @package System.Caching
+ * @since 3.1.0
+ */
+class TDirectoryCacheDependency extends TCacheDependency
+{
+	private $_recursiveCheck=true;
+	private $_recursiveLevel=-1;
+	private $_timestamps;
+	private $_directory;
+
+	/**
+	 * Constructor.
+	 * @param string the directory to be checked
+	 */
+	public function __construct($directory)
+	{
+		$this->setDirectory($directory);
+	}
+
+	/**
+	 * @return string the directory to be checked
+	 */
+	public function getDirectory()
+	{
+		return $this->_directory;
+	}
+
+	/**
+	 * @param string the directory to be checked
+	 * @throws TInvalidDataValueException if the directory does not exist
+	 */
+	public function setDirectory($directory)
+	{
+		if(($path=realpath($directory))===false || !is_dir($path))
+			throw new TInvalidDataValueException('directorycachedependency_directory_invalid',$directory);
+		$this->_directory=$path;
+		$this->_timestamps=$this->generateTimestamps($path);
+	}
+
+	/**
+	 * @return boolean whether the subdirectories of the directory will also be checked.
+	 * It defaults to true.
+	 */
+	public function getRecursiveCheck()
+	{
+		return $this->_recursiveCheck;
+	}
+
+	/**
+	 * @param boolean whether the subdirectories of the directory will also be checked.
+	 */
+	public function setRecursiveCheck($value)
+	{
+		$this->_recursiveCheck=TPropertyValue::ensureBoolean($value);
+	}
+
+	/**
+	 * @return int the depth of the subdirectories to be checked.
+	 * It defaults to -1, meaning unlimited depth.
+	 */
+	public function getRecursiveLevel()
+	{
+		return $this->_recursiveLevel;
+	}
+
+	/**
+	 * Sets a value indicating the depth of the subdirectories to be checked.
+	 * This is meaningful only when {@link getRecursiveCheck RecursiveCheck}
+	 * is true.
+	 * @param int the depth of the subdirectories to be checked.
+	 * If the value is less than 0, it means unlimited depth.
+	 * If the value is 0, it means checking the files directly under the specified directory.
+	 */
+	public function setRecursiveLevel($value)
+	{
+		$this->_recursiveLevel=TPropertyValue::ensureInteger($value);
+	}
+
+	/**
+	 * Performs the actual dependency checking.
+	 * This method returns true if the directory is changed.
+	 * @return boolean whether the dependency is changed or not.
+	 */
+	public function getHasChanged()
+	{
+		return $this->generateTimestamps($this->_directory)!=$this->_timestamps;
+	}
+
+	/**
+	 * Checks to see if the file should be checked for dependency.
+	 * This method is invoked when dependency of the whole directory is being checked.
+	 * By default, it always returns true, meaning the file should be checked.
+	 * You may override this method to check only certain files.
+	 * @param string the name of the file that may be checked for dependency.
+	 * @return boolean whether this file should be checked.
+	 */
+	protected function validateFile($fileName)
+	{
+		return true;
+	}
+
+	/**
+	 * Checks to see if the specified subdirectory should be checked for dependency.
+	 * This method is invoked when dependency of the whole directory is being checked.
+	 * By default, it always returns true, meaning the subdirectory should be checked.
+	 * You may override this method to check only certain subdirectories.
+	 * @param string the name of the subdirectory that may be checked for dependency.
+	 * @return boolean whether this subdirectory should be checked.
+	 */
+	protected function validateDirectory($directory)
+	{
+		return true;
+	}
+
+	/**
+	 * Determines the last modification time for files under the directory.
+	 * This method may go recursively into subdirectories if
+	 * {@link setRecursiveCheck RecursiveCheck} is set true.
+	 * @param string the directory name
+	 * @param int level of the recursion
+	 * @return array list of file modification time indexed by the file path
+	 */
+	protected function generateTimestamps($directory,$level=0)
+	{
+		if(($dir=opendir($directory))===false)
+			throw new TIOException('directorycachedependency_directory_invalid',$directory);
+		$timestamps=array();
+		while(($file=readdir($dir))!==false)
+		{
+			$path=$directory.DIRECTORY_SEPARATOR.$file;
+			if($file==='.' || $file==='..')
+				continue;
+			else if(is_dir($path))
+			{
+				if(($this->_recursiveLevel<0 || $level<$this->_recursiveLevel) && $this->validateDirectory($path))
+					$timestamps=array_merge($this->generateTimestamps($path,$level+1));
+			}
+			else if($this->validateFile($path))
+				$timestamps[$path]=filemtime($path);
+		}
+		closedir($dir);
+		return $timestamps;
+	}
+}
+
+
+/**
+ * TGlobalStateCacheDependency class.
+ *
+ * TGlobalStateCacheDependency checks if a global state is changed or not.
+ * If the global state is changed, the dependency is reported as changed.
+ * To specify which global state this dependency should check with,
+ * set {@link setStateName StateName} to the name of the global state.
+ *
+ * @author Qiang Xue <qiang.xue@gmail.com>
+ * @package System.Caching
+ * @since 3.1.0
+ */
+class TGlobalStateCacheDependency extends TCacheDependency
+{
+	private $_stateName;
+	private $_stateValue;
+
+	/**
+	 * Constructor.
+	 * @param string the name of the global state
+	 */
+	public function __construct($name)
+	{
+		$this->setStateName($name);
+	}
+
+	/**
+	 * @return string the name of the global state
+	 */
+	public function getStateName()
+	{
+		return $this->_stateName;
+	}
+
+	/**
+	 * @param string the name of the global state
+	 * @see TApplication::setGlobalState
+	 */
+	public function setStateName($value)
+	{
+		$this->_stateName=$value;
+		$this->_stateValue=Prado::getApplication()->getGlobalState($value);
+	}
+
+	/**
+	 * Performs the actual dependency checking.
+	 * This method returns true if the specified global state is changed.
+	 * @return boolean whether the dependency is changed or not.
+	 */
+	public function getHasChanged()
+	{
+		return $this->_stateValue!==Prado::getApplication()->getGlobalState($this->_stateName);
+	}
+}
+
+
+/**
+ * TChainedCacheDependency class.
+ *
+ * TChainedCacheDependency represents a list of cache dependency objects
+ * and performs the dependency checking based on the checking results of
+ * these objects. If any of them reports a dependency change, TChainedCacheDependency
+ * will return true for the checking.
+ *
+ * To add dependencies to TChainedCacheDependency, use {@link getDependencies Dependencies}
+ * which gives a {@link TCacheDependencyList} instance and can be used like an array
+ * (see {@link TList} for more details}).
+ *
+ * @author Qiang Xue <qiang.xue@gmail.com>
+ * @package System.Caching
+ * @since 3.1.0
+ */
+class TChainedCacheDependency extends TCacheDependency
+{
+	private $_dependencies=null;
+
+	/**
+	 * @return TCacheDependencyList list of dependency objects
+	 */
+	public function getDependencies()
+	{
+		if($this->_dependencies===null)
+			$this->_dependencies=new TCacheDependencyList;
+		return $this->_dependencies;
+	}
+
+	/**
+	 * Performs the actual dependency checking.
+	 * This method returns true if any of the dependency objects
+	 * reports a dependency change.
+	 * @return boolean whether the dependency is changed or not.
+	 */
+	public function getHasChanged()
+	{
+		if($this->_dependencies!==null)
+		{
+			foreach($this->_dependencies as $dependency)
+				if($dependency->getHasChanged())
+					return true;
+		}
+		return false;
+	}
+}
+
+
+/**
+ * TApplicationStateCacheDependency class.
+ *
+ * TApplicationStateCacheDependency performs dependency checking based on
+ * the mode of the currently running PRADO application.
+ * The dependency is reportedly as unchanged if and only if the application
+ * is running in performance mode.
+ *
+ * You may chain this dependency together with other dependencies
+ * so that only when the application is not in performance mode the other dependencies
+ * will be checked.
+ *
+ * @author Qiang Xue <qiang.xue@gmail.com>
+ * @package System.Caching
+ * @since 3.1.0
+ */
+class TApplicationStateCacheDependency extends TCacheDependency
+{
+	/**
+	 * Performs the actual dependency checking.
+	 * This method returns true if the currently running application is not in performance mode.
+	 * @return boolean whether the dependency is changed or not.
+	 */
+	public function getHasChanged()
+	{
+		return Prado::getApplication()->getMode()!==TApplicationMode::Performance;
+	}
+}
+
+/**
+ * TCacheDependencyList class.
+ *
+ * TCacheDependencyList represents a list of cache dependency objects.
+ * Only objects implementing {@link ICacheDependency} can be added into this list.
+ *
+ * TCacheDependencyList can be used like an array. See {@link TList}
+ * for more details.
+ *
+ * @author Qiang Xue <qiang.xue@gmail.com>
+ * @package System.Caching
+ * @since 3.1.0
+ */
+class TCacheDependencyList extends TList
+{
+	/**
+	 * Inserts an item at the specified position.
+	 * This overrides the parent implementation by performing additional type checking
+	 * for each newly added item.
+	 * @param integer the specified position.
+	 * @param mixed new item
+	 * @throws TInvalidDataTypeException if the item to be inserted is not a dependency instance
+	 */
+	public function insertAt($index,$item)
+	{
+		if($item instanceof ICacheDependency)
+			parent::insertAt($index,$item);
+		else
+			throw new TInvalidDataTypeException('cachedependencylist_cachedependency_required');
+	}
+}
+
diff --git a/lib/prado/framework/Caching/TDbCache.php b/lib/prado/framework/Caching/TDbCache.php
new file mode 100644
index 0000000..f0cf962
--- /dev/null
+++ b/lib/prado/framework/Caching/TDbCache.php
@@ -0,0 +1,576 @@
+<?php
+/**
+ * TDbCache class file
+ *
+ * @author Qiang Xue <qiang.xue@gmail.com>
+ * @link https://github.com/pradosoft/prado
+ * @copyright Copyright &copy; 2005-2015 The PRADO Group
+ * @license https://github.com/pradosoft/prado/blob/master/COPYRIGHT
+ * @package System.Caching
+ */
+
+Prado::using('System.Data.TDbConnection');
+
+/**
+ * TDbCache class
+ *
+ * TDbCache implements a cache application module by storing cached data in a database.
+ *
+ * TDbCache relies on {@link http://www.php.net/manual/en/ref.pdo.php PDO} to retrieve
+ * data from databases. In order to use TDbCache, you need to enable the PDO extension
+ * as well as the corresponding PDO DB driver. For example, to use SQLite database
+ * to store cached data, you need both php_pdo and php_pdo_sqlite extensions.
+ *
+ * By default, TDbCache creates and uses an SQLite database under the application
+ * runtime directory. You may change this default setting by specifying the following
+ * properties:
+ * - {@link setConnectionID ConnectionID} or
+ * - {@link setConnectionString ConnectionString}, {@link setUsername Username} and {@link setPassword Pasword}.
+ *
+ * The cached data is stored in a table in the specified database.
+ * By default, the name of the table is called 'pradocache'. If the table does not
+ * exist in the database, it will be automatically created with the following structure:
+ * <code>
+ * CREATE TABLE pradocache (itemkey CHAR(128), value BLOB, expire INT)
+ * CREATE INDEX IX_itemkey ON pradocache (itemkey)
+ * CREATE INDEX IX_expire ON pradocache (expire)
+ * </code>
+ *
+ * Note, some DBMS might not support BLOB type. In this case, replace 'BLOB' with a suitable
+ * binary data type (e.g. LONGBLOB in MySQL, BYTEA in PostgreSQL.)
+ *
+ * Important: Make sure that the indices are non-unique!
+ *
+ * If you want to change the cache table name, or if you want to create the table by yourself,
+ * you may set {@link setCacheTableName CacheTableName} and {@link setAutoCreateCacheTable AutoCreateCacheTableName} properties.
+ *
+ * {@link setFlushInterval FlushInterval} control how often expired items will be removed from cache.
+ * If you prefer to remove expired items manualy e.g. via cronjob you can disable automatic deletion by setting FlushInterval to '0'.
+ *
+ * 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 by
+ * the number of seconds. 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.
+ *
+ * Do not use the same database file for multiple applications using TDbCache.
+ * Also note, cache is shared by all user sessions of an application.
+ *
+ * Some usage examples of TDbCache are as follows,
+ * <code>
+ * $cache=new TDbCache;  // TDbCache may also be loaded as a Prado application module
+ * $cache->init(null);
+ * $cache->add('object',$object);
+ * $object2=$cache->get('object');
+ * </code>
+ *
+ * If loaded, TDbCache will register itself with {@link TApplication} as the
+ * cache module. It can be accessed via {@link TApplication::getCache()}.
+ *
+ * TDbCache may be configured in application configuration file as follows
+ * <code>
+ * <module id="cache" class="System.Caching.TDbCache" />
+ * </code>
+ *
+ * @author Qiang Xue <qiang.xue@gmail.com>
+ * @package System.Caching
+ * @since 3.1.0
+ */
+class TDbCache extends TCache
+{
+	/**
+	 * @var string the ID of TDataSourceConfig module
+	 */
+	private $_connID='';
+	/**
+	 * @var TDbConnection the DB connection instance
+	 */
+	private $_db;
+	/**
+	 * @var string name of the DB cache table
+	 */
+	private $_cacheTable='pradocache';
+	/**
+	 * @var integer Interval expired items will be removed from cache
+	 */
+	private $_flushInterval=60;
+	/**
+	 * @var boolean
+	 */
+	private $_cacheInitialized = false;
+	/**
+	 * @var boolean
+	 */
+	private $_createCheck= false;
+	/**
+	 * @var boolean whether the cache DB table should be created automatically
+	 */
+	private $_autoCreate=true;
+	private $_username='';
+	private $_password='';
+	private $_connectionString='';
+
+	/**
+	 * Destructor.
+	 * Disconnect the db connection.
+	 */
+	public function __destruct()
+	{
+		if($this->_db!==null)
+			$this->_db->setActive(false);
+	}
+
+	/**
+	 * Initializes this module.
+	 * This method is required by the IModule interface.
+	 * attach {@link doInitializeCache} to TApplication.OnLoadStateComplete event
+	 * attach {@link doFlushCacheExpired} to TApplication.OnSaveState event
+	 *
+	 * @param TXmlElement configuration for this module, can be null
+	 */
+	public function init($config)
+	{
+		$this -> getApplication() -> attachEventHandler('OnLoadStateComplete', array($this, 'doInitializeCache'));
+		$this -> getApplication() -> attachEventHandler('OnSaveState', array($this, 'doFlushCacheExpired'));
+		parent::init($config);
+	}
+
+	/**
+	 * Event listener for TApplication.OnSaveState
+	 * @return void
+	 * @since 3.1.5
+	 * @see flushCacheExpired
+	 */
+	public function doFlushCacheExpired()
+	{
+		$this->flushCacheExpired(false);
+	}
+
+	/**
+	 * Event listener for TApplication.OnLoadStateComplete
+	 *
+	 * @return void
+	 * @since 3.1.5
+	 * @see initializeCache
+	 */
+	public function doInitializeCache()
+	{
+		$this->initializeCache();
+	}
+
+	/**
+	 * Initialize TDbCache
+	 *
+	 * If {@link setAutoCreateCacheTable AutoCreateCacheTableName} is 'true' check existence of cache table
+	 * and create table if does not exist.
+	 *
+	 * @param boolean Force override global state check
+	 * @return void
+	 * @throws TConfigurationException if any error happens during creating database or cache table.
+	 * @since 3.1.5
+	 */
+	protected function initializeCache($force=false)
+	{
+		if($this->_cacheInitialized && !$force) return;
+		$db=$this->getDbConnection();
+		try
+		{
+			$key = 'TDbCache:' . $this->_cacheTable . ':created';
+			if($force)
+				$this -> _createCheck = false;
+			else
+				$this -> _createCheck = $this -> getApplication() -> getGlobalState($key, 0);
+
+			if($this->_autoCreate && !$this -> _createCheck) {
+
+				Prado::trace(($force ? 'Force initializing: ' : 'Initializing: ') . $this -> id . ', ' . $this->_cacheTable, 'System.Caching.TDbCache');
+
+				$sql='SELECT 1 FROM '.$this->_cacheTable.' WHERE 0=1';
+				$db->createCommand($sql)->queryScalar();
+
+				$this -> _createCheck = true;
+				$this -> getApplication() -> setGlobalState($key, time());
+			}
+		}
+		catch(Exception $e)
+		{
+			// DB table not exists
+			if($this->_autoCreate)
+			{
+				Prado::trace('Autocreate: ' . $this->_cacheTable, 'System.Caching.TDbCache');
+
+				$driver=$db->getDriverName();
+				if($driver==='mysql')
+					$blob='LONGBLOB';
+				else if($driver==='pgsql')
+					$blob='BYTEA';
+				else
+					$blob='BLOB';
+
+				$sql='CREATE TABLE '.$this->_cacheTable." (itemkey CHAR(128) PRIMARY KEY, value $blob, expire INTEGER)";
+				$db->createCommand($sql)->execute();
+
+				$sql='CREATE INDEX IX_expire ON ' . $this->_cacheTable . ' (expire)';
+				$db->createCommand($sql)->execute();
+
+				$this -> _createCheck = true;
+				$this -> getApplication() -> setGlobalState($key, time());
+			}
+			else
+				throw new TConfigurationException('db_cachetable_inexistent',$this->_cacheTable);
+		}
+		$this->_cacheInitialized = true;
+	}
+
+	/**
+	 * Flush expired values from cache depending on {@link setFlushInterval FlushInterval}
+	 * @param boolean override {@link setFlushInterval FlushInterval} and force deletion of expired items
+	 * @return void
+	 * @since 3.1.5
+	 */
+	public function flushCacheExpired($force=false)
+	{
+		$interval = $this -> getFlushInterval();
+		if(!$force && $interval === 0) return;
+
+		$key	= 'TDbCache:' . $this->_cacheTable . ':flushed';
+		$now	= time();
+		$next	= $interval + (integer)$this -> getApplication() -> getGlobalState($key, 0);
+
+		if($force || $next <= $now)
+		{
+			if(!$this->_cacheInitialized) $this->initializeCache();
+			Prado::trace(($force ? 'Force flush of expired items: ' : 'Flush expired items: ') . $this -> id . ', ' . $this->_cacheTable, 'System.Caching.TDbCache');
+			$sql='DELETE FROM '.$this->_cacheTable.' WHERE expire<>0 AND expire<'.$now;
+			$this->getDbConnection()->createCommand($sql)->execute();
+			$this -> getApplication() -> setGlobalState($key, $now);
+		}
+	}
+
+	/**
+	 * @return integer Interval in sec expired items will be removed from cache. Default to 60
+	 * @since 3.1.5
+	 */
+	public function getFlushInterval()
+	{
+		return $this->_flushInterval;
+	}
+
+	/**
+	 * Sets interval expired items will be removed from cache
+	 *
+	 * To disable automatic deletion of expired items,
+	 * e.g. for external flushing via cron you can set value to '0'
+	 *
+	 * @param integer Interval in sec
+	 * @since 3.1.5
+	 */
+	public function setFlushInterval($value)
+	{
+		$this->_flushInterval = (integer) $value;
+	}
+
+	/**
+	 * Creates the DB connection.
+	 * @param string the module ID for TDataSourceConfig
+	 * @return TDbConnection the created DB connection
+	 * @throws TConfigurationException if module ID is invalid or empty
+	 */
+	protected function createDbConnection()
+	{
+		if($this->_connID!=='')
+		{
+			$config=$this->getApplication()->getModule($this->_connID);
+			if($config instanceof TDataSourceConfig)
+				return $config->getDbConnection();
+			else
+				throw new TConfigurationException('dbcache_connectionid_invalid',$this->_connID);
+		}
+		else
+		{
+			$db=new TDbConnection;
+			if($this->_connectionString!=='')
+			{
+				$db->setConnectionString($this->_connectionString);
+				if($this->_username!=='')
+					$db->setUsername($this->_username);
+				if($this->_password!=='')
+					$db->setPassword($this->_password);
+			}
+			else
+			{
+				// default to SQLite3 database
+				$dbFile=$this->getApplication()->getRuntimePath().'/sqlite3.cache';
+				$db->setConnectionString('sqlite:'.$dbFile);
+			}
+			return $db;
+		}
+	}
+
+	/**
+	 * @return TDbConnection the DB connection instance
+	 */
+	public function getDbConnection()
+	{
+		if($this->_db===null)
+			$this->_db=$this->createDbConnection();
+
+		$this->_db->setActive(true);
+		return $this->_db;
+	}
+
+	/**
+	 * @return string the ID of a {@link TDataSourceConfig} module. Defaults to empty string, meaning not set.
+	 * @since 3.1.1
+	 */
+	public function getConnectionID()
+	{
+		return $this->_connID;
+	}
+
+	/**
+	 * Sets the ID of a TDataSourceConfig module.
+	 * The datasource module will be used to establish the DB connection for this cache module.
+	 * The database connection can also be specified via {@link setConnectionString ConnectionString}.
+	 * When both ConnectionID and ConnectionString are specified, the former takes precedence.
+	 * @param string ID of the {@link TDataSourceConfig} module
+	 * @since 3.1.1
+	 */
+	public function setConnectionID($value)
+	{
+		$this->_connID=$value;
+	}
+
+	/**
+	 * @return string The Data Source Name, or DSN, contains the information required to connect to the database.
+	 */
+	public function getConnectionString()
+	{
+		return $this->_connectionString;
+	}
+
+	/**
+	 * @param string The Data Source Name, or DSN, contains the information required to connect to the database.
+	 * @see http://www.php.net/manual/en/function.pdo-construct.php
+	 */
+	public function setConnectionString($value)
+	{
+		$this->_connectionString=$value;
+	}
+
+	/**
+	 * @return string the username for establishing DB connection. Defaults to empty string.
+	 */
+	public function getUsername()
+	{
+		return $this->_username;
+	}
+
+	/**
+	 * @param string the username for establishing DB connection
+	 */
+	public function setUsername($value)
+	{
+		$this->_username=$value;
+	}
+
+	/**
+	 * @return string the password for establishing DB connection. Defaults to empty string.
+	 */
+	public function getPassword()
+	{
+		return $this->_password;
+	}
+
+	/**
+	 * @param string the password for establishing DB connection
+	 */
+	public function setPassword($value)
+	{
+		$this->_password=$value;
+	}
+
+	/**
+	 * @return string the name of the DB table to store cache content. Defaults to 'pradocache'.
+	 * @see setAutoCreateCacheTable
+	 */
+	public function getCacheTableName()
+	{
+		return $this->_cacheTable;
+	}
+
+	/**
+	 * Sets the name of the DB table to store cache content.
+	 * Note, if {@link setAutoCreateCacheTable AutoCreateCacheTable} is false
+	 * and you want to create the DB table manually by yourself,
+	 * you need to make sure the DB table is of the following structure:
+	 * <code>
+	 * CREATE TABLE pradocache (itemkey CHAR(128), value BLOB, expire INT)
+	 * CREATE INDEX IX_itemkey ON pradocache (itemkey)
+	 * CREATE INDEX IX_expire ON pradocache (expire)
+	 * </code>
+	 *
+	 * Note, some DBMS might not support BLOB type. In this case, replace 'BLOB' with a suitable
+	 * binary data type (e.g. LONGBLOB in MySQL, BYTEA in PostgreSQL.)
+	 *
+	 * Important: Make sure that the indices are non-unique!
+	 *
+	 * @param string the name of the DB table to store cache content
+	 * @see setAutoCreateCacheTable
+	 */
+	public function setCacheTableName($value)
+	{
+		$this->_cacheTable=$value;
+	}
+
+	/**
+	 * @return boolean whether the cache DB table should be automatically created if not exists. Defaults to true.
+	 * @see setAutoCreateCacheTable
+	 */
+	public function getAutoCreateCacheTable()
+	{
+		return $this->_autoCreate;
+	}
+
+	/**
+	 * @param boolean whether the cache DB table should be automatically created if not exists.
+	 * @see setCacheTableName
+	 */
+	public function setAutoCreateCacheTable($value)
+	{
+		$this->_autoCreate=TPropertyValue::ensureBoolean($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($key)
+	{
+		if(!$this->_cacheInitialized) $this->initializeCache();
+		try {
+			$sql='SELECT value FROM '.$this->_cacheTable.' WHERE itemkey=\''.$key.'\' AND (expire=0 OR expire>'.time().') ORDER BY expire DESC';
+			$command=$this->getDbConnection()->createCommand($sql);
+			return unserialize($command->queryScalar());
+		}
+		catch(Exception $e)
+		{
+			$this->initializeCache(true);
+			return unserialize($command->queryScalar());
+		}
+	}
+
+	/**
+	 * 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)
+	{
+		$this->deleteValue($key);
+		return $this->addValue($key,$value,$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,$expire)
+	{
+		if(!$this->_cacheInitialized) $this->initializeCache();
+		$expire=($expire<=0)?0:time()+$expire;
+		$sql="INSERT INTO {$this->_cacheTable} (itemkey,value,expire) VALUES(:key,:value,$expire)";
+		try
+		{
+			$command=$this->getDbConnection()->createCommand($sql);
+			$command->bindValue(':key',$key,PDO::PARAM_STR);
+			$command->bindValue(':value',serialize($value),PDO::PARAM_LOB);
+			$command->execute();
+			return true;
+		}
+		catch(Exception $e)
+		{
+			try
+			{
+				$this->initializeCache(true);
+				$command->execute();
+				return true;
+			}
+			catch(Exception $e)
+			{
+				return false;
+			}
+		}
+	}
+
+	/**
+	 * Deletes a value with the specified key from cache
+	 * This is the implementation of the method declared in the parent class.
+	 * @param string the key of the value to be deleted
+	 * @return boolean if no error happens during deletion
+	 */
+	protected function deleteValue($key)
+	{
+		if(!$this->_cacheInitialized) $this->initializeCache();
+		try
+		{
+			$command=$this->getDbConnection()->createCommand("DELETE FROM {$this->_cacheTable} WHERE itemkey=:key");
+			$command->bindValue(':key',$key,PDO::PARAM_STR);
+			$command->execute();
+			return true;
+		}
+		catch(Exception $e)
+		{
+			$this->initializeCache(true);
+			$command->execute();
+			return true;
+		}
+	}
+
+	/**
+	 * Deletes all values from cache.
+	 * Be careful of performing this operation if the cache is shared by multiple applications.
+	 */
+	public function flush()
+	{
+		if(!$this->_cacheInitialized) $this->initializeCache();
+		try
+		{
+			$command = $this->getDbConnection()->createCommand("DELETE FROM {$this->_cacheTable}");
+			$command->execute();
+		}
+		catch(Exception $e)
+		{
+			try
+			{
+				$this->initializeCache(true);
+				$command->execute();
+				return true;
+			}
+			catch(Exception $e)
+			{
+				return false;
+			}
+		}
+		return true;
+	}
+}
diff --git a/lib/prado/framework/Caching/TEACache.php b/lib/prado/framework/Caching/TEACache.php
new file mode 100644
index 0000000..251566b
--- /dev/null
+++ b/lib/prado/framework/Caching/TEACache.php
@@ -0,0 +1 @@
+<?php
/**
 * TEACache class file
 *
 * @author Dario rigolin <drigolin@e-portaltech.it>
 * @link https://github.com/pradosoft/prado
 * @copyright Copyright &copy; 2005-2015 The PRADO Group
 * @license https://github.com/pradosoft/prado/blob/master/COPYRIGHT
 * @package System.Caching
 */

/**
 * TEACache class
 *
 * TEACache implements a cache application module based on {@link http://eaccelerator.net/ eAccelerator}.
 *
 * 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.
 *
 * To use this module, the eAccelerator PHP extension must be loaded and enabled
 *
 * Please note that as of v0.9.6, eAccelerator no longer supports data caching.
 * This means if you still want to use this component, your eAccelerator should be of 0.9.5.x or lower version.
 *
 * Some usage examples of TEACache are as follows,
 * <code>
 * $cache=new TEACache;  // TEACache may also be loaded as a Prado application module
 * $cache->init(null);
 * $cache->add('object',$object);
 * $object2=$cache->get('object');
 * </code>
 *
 * If loaded, TEACache will register itself with {@link TApplication} as the
 * cache module. It can be accessed via {@link TApplication::getCache()}.
 *
 * TEACache may be configured in application configuration file as follows
 * <code>
 * <module id="cache" class="System.Caching.TEACache" />
 * </code>
 *
 * @author Dario Rigolin <drigolin@e-portaltech.it>
 * @package System.Caching
 * @since 3.2.2
 */
class TEACache extends TCache
{
   /**
    * Initializes this module.
    * This method is required by the IModule interface.
    * @param TXmlElement configuration for this module, can be null
    * @throws TConfigurationException if eaccelerator extension is not installed or not started, check your php.ini
    */
	public function init($config)
	{
		if(!function_exists('eaccelerator_get'))
			throw new TConfigurationException('eacceleratorcache_extension_required');
		parent::init($config);
	}

	/**
	 * 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)
	{
		$value = eaccelerator_get($key);
		return ($value === null) ? false : $value;
	}

	/**
	 * 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,$expire)
	{
		return eaccelerator_put($key,$value,$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,$expire)
	{
		return (null === eaccelerator_get($key)) ? $this->setValue($key,$value,$expire) : false;
	}

	/**
	 * 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($key)
	{
		return eaccelerator_rm($key);
	}

	/**
	 * Deletes all values from cache.
	 * Be careful of performing this operation if the cache is shared by multiple applications.
	 */
	public function flush()
	{
		// first, remove expired content from cache
		eaccelerator_gc();
		// now, remove leftover cache-keys
		$keys = eaccelerator_list_keys();
		foreach($keys as $key)
			$this->deleteValue(substr($key['name'], 1));
		return true;
	}
}
\ No newline at end of file
diff --git a/lib/prado/framework/Caching/TMemCache.php b/lib/prado/framework/Caching/TMemCache.php
new file mode 100644
index 0000000..8d09119
--- /dev/null
+++ b/lib/prado/framework/Caching/TMemCache.php
@@ -0,0 +1,400 @@
+<?php
+/**
+ * TMemCache class file
+ *
+ * @author Qiang Xue <qiang.xue@gmail.com>
+ * @author Carl G. Mathisen <carlgmathisen@gmail.com>
+ * @link https://github.com/pradosoft/prado
+ * @copyright Copyright &copy; 2005-2015 The PRADO Group
+ * @license https://github.com/pradosoft/prado/blob/master/COPYRIGHT
+ * @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.
+ *
+ * Automatic compression of values may be used (using zlib extension) by setting {@link getThreshold Threshold} and {@link getMinSavings MinSavings} properties.
+ * NB : MemCache server(s) must be restarted to apply settings. Require (PECL memcache >= 2.0.0) or memcached if {@link useMemcached} is true.
+ *
+ * @author Qiang Xue <qiang.xue@gmail.com>
+ * @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;
+	/**
+	* @var integer Controls the minimum value length before attempting to compress automatically.
+	*/
+    private $_threshold=0;
+
+	/**
+	* @var float Specifies the minimum amount of savings to actually store the value compressed. The supplied value must be between 0 and 1. Default value is 0.2 giving a minimum 20% compression savings.
+	*/
+    private $_minSavings=0.0;
+
+    private $_status = true;
+
+    private $_failureCallback = null;
+
+	/**
+	 * @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.
+	 */
+	private $_useMemcached=false;
+	
+	/**
+	 * @var array list of servers available
+	 */
+	private $_servers=array();
+
+	/**
+	 * Destructor.
+	 * Disconnect the memcache server.
+	 */
+	public function __destruct()
+	{
+		if($this->_cache!==null && !$this->_useMemcached)
+			$this->_cache->close();
+	}
+
+	/**
+	 * Initializes this module.
+	 * This method is required by the IModule interface. It makes sure that
+	 * UniquePrefix has been set, creates a Memcache instance and connects
+	 * to the memcache server.
+	 * @param TApplication Prado application, can be null
+	 * @param TXmlElement configuration for this module, can be null
+	 * @throws TConfigurationException if memcache extension is not installed or memcache sever connection fails
+	 */
+	public function init($config)
+	{
+		if(!extension_loaded('memcache') && !$this->_useMemcached)
+			throw new TConfigurationException('memcache_extension_required');
+		if(!extension_loaded('memcached') && $this->_useMemcached)
+			throw new TConfigurationException('memcached_extension_required');
+		
+		$this->_cache = $this->_useMemcached ? new Memcached : 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->_threshold!==0)
+            $this->_cache->setCompressThreshold($this->_threshold,$this->_minSavings);
+		$this->_initialized=true;
+		parent::init($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);
+	}
+	
+	/**
+	 * @return boolean if memcached instead memcache
+	 */
+	public function getUseMemcached()
+	{
+		return $this->_useMemcached;
+	}
+
+	/**
+	 * @param string if memcached instead memcache
+	 * @throws TInvalidOperationException if the module is already initialized
+	 */
+	public function setUseMemcached($value)
+	{
+		if($this->_initialized)
+			throw new TInvalidOperationException('memcache_host_unchangeable');
+		else
+			$this->_useMemcached=$value;
+	}
+	
+	/**
+	 * @return integer minimum value length before attempting to compress
+	 */
+	public function getThreshold()
+	{
+		return $this->_threshold;
+	}
+
+	/**
+	 * @param integer minimum value length before attempting to compress
+	 * @throws TInvalidOperationException if the module is already initialized
+	 */
+	public function setThreshold($value)
+	{
+		if($this->_initialized)
+			throw new TInvalidOperationException('memcache_threshold_unchangeable');
+		else
+			$this->_threshold=TPropertyValue::ensureInteger($value);
+	}
+
+	/**
+	 * @return float minimum amount of savings to actually store the value compressed
+	 */
+	public function getMinSavings()
+	{
+		return $this->_minSavings;
+	}
+
+	/**
+	 * @param float minimum amount of savings to actually store the value compressed
+	 * @throws TInvalidOperationException if the module is already initialized
+	 */
+	public function setMinSavings($value)
+	{
+		if($this->_initialized)
+			throw new TInvalidOperationException('memcache_min_savings_unchangeable');
+		else
+			$this->_minSavings=TPropertyValue::ensureFloat($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,$expire)
+	{
+		if($this->_useMemcached) {
+			return $this->_cache->set($key,$value,$expire);
+		} else {
+			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,$expire)
+	{
+		if($this->_useMemcached) {
+			$this->_cache->add($key,$value,$expire);
+		} else {
+			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();
+	}
+}
+
diff --git a/lib/prado/framework/Caching/TSqliteCache.php b/lib/prado/framework/Caching/TSqliteCache.php
new file mode 100644
index 0000000..8451a9e
--- /dev/null
+++ b/lib/prado/framework/Caching/TSqliteCache.php
@@ -0,0 +1,222 @@
+<?php
+/**
+ * TSqliteCache class file
+ *
+ * @author Qiang Xue <qiang.xue@gmail.com>
+ * @link https://github.com/pradosoft/prado
+ * @copyright Copyright &copy; 2005-2015 The PRADO Group
+ * @license https://github.com/pradosoft/prado/blob/master/COPYRIGHT
+ * @package System.Caching
+ */
+
+/**
+ * TSqliteCache class
+ *
+ * TSqliteCache implements a cache application module based on SQLite database.
+ *
+ * THIS CLASS IS DEPRECATED since it relies on the sqlite PHP extension, that is
+ * no longer loaded by default since PHP 5.1. You are discouraged from using it:
+ * use {@link TDbCache} instead.
+ *
+ * Since PRADO v3.1.0, a new DB-based cache module called {@link TDbCache}
+ * is provided. If you have PDO extension installed, you may consider using
+ * the new cache module instead as it allows you to use different database
+ * to store the cached data.
+ *
+ * The database file is specified by the {@link setDbFile DbFile} property.
+ * If not set, the database file will be created under the system state path.
+ * If the specified database file does not exist, it will be created automatically.
+ * Make sure the directory containing the specified DB file and the file itself is
+ * writable by the Web server process.
+ *
+ * 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 by
+ * the number of seconds. 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.
+ *
+ * Do not use the same database file for multiple applications using TSqliteCache.
+ * Also note, cache is shared by all user sessions of an application.
+ *
+ * Some usage examples of TSqliteCache are as follows,
+ * <code>
+ * $cache=new TSqliteCache;  // TSqliteCache may also be loaded as a Prado application module
+ * $cache->setDbFile($dbFilePath);
+ * $cache->init(null);
+ * $cache->add('object',$object);
+ * $object2=$cache->get('object');
+ * </code>
+ *
+ * If loaded, TSqliteCache will register itself with {@link TApplication} as the
+ * cache module. It can be accessed via {@link TApplication::getCache()}.
+ *
+ * TSqliteCache may be configured in application configuration file as follows
+ * <code>
+ * <module id="cache" class="System.Caching.TSqliteCache" DbFile="Application.Data.site" />
+ * </code>
+ * where {@link getDbFile DbFile} is a property specifying the location of the
+ * SQLite DB file (in the namespace format).
+ *
+ * @author Qiang Xue <qiang.xue@gmail.com>
+ * @package System.Caching
+ * @since 3.0
+ */
+class TSqliteCache extends TCache
+{
+	/**
+	 * name of the table storing cache data
+	 */
+	const CACHE_TABLE='cache';
+	/**
+	 * extension of the db file name
+	 */
+	const DB_FILE_EXT='.db';
+
+	/**
+	 * @var boolean if the module has been initialized
+	 */
+	private $_initialized=false;
+	/**
+	 * @var SQLiteDatabase the sqlite database instance
+	 */
+	private $_db=null;
+	/**
+	 * @var string the database file name
+	 */
+	private $_file=null;
+
+	/**
+	 * Destructor.
+	 * Disconnect the db connection.
+	 */
+	public function __destruct()
+	{
+		$this->_db=null;
+	}
+
+	/**
+	 * Initializes this module.
+	 * This method is required by the IModule interface. It checks if the DbFile
+	 * property is set, and creates a SQLiteDatabase instance for it.
+	 * The database or the cache table does not exist, they will be created.
+	 * Expired values are also deleted.
+	 * @param TXmlElement configuration for this module, can be null
+	 * @throws TConfigurationException if sqlite extension is not installed,
+	 *         DbFile is set invalid, or any error happens during creating database or cache table.
+	 */
+	public function init($config)
+	{
+		if(!function_exists('sqlite_open'))
+			throw new TConfigurationException('sqlitecache_extension_required');
+		if($this->_file===null)
+			$this->_file=$this->getApplication()->getRuntimePath().'/sqlite.cache';
+		$error='';
+		if(($this->_db=new SQLiteDatabase($this->_file,0666,$error))===false)
+			throw new TConfigurationException('sqlitecache_connection_failed',$error);
+		if(@$this->_db->query('DELETE FROM '.self::CACHE_TABLE.' WHERE expire<>0 AND expire<'.time())===false)
+		{
+			if($this->_db->query('CREATE TABLE '.self::CACHE_TABLE.' (key CHAR(128) PRIMARY KEY, value BLOB, expire INT)')===false)
+				throw new TConfigurationException('sqlitecache_table_creation_failed',sqlite_error_string(sqlite_last_error()));
+		}
+		$this->_initialized=true;
+		parent::init($config);
+	}
+
+	/**
+	 * @return string database file path (in namespace form)
+	 */
+	public function getDbFile()
+	{
+		return $this->_file;
+	}
+
+	/**
+	 * @param string database file path (in namespace form)
+	 * @throws TInvalidOperationException if the module is already initialized
+	 * @throws TConfigurationException if the file is not in proper namespace format
+	 */
+	public function setDbFile($value)
+	{
+		if($this->_initialized)
+			throw new TInvalidOperationException('sqlitecache_dbfile_unchangeable');
+		else if(($this->_file=Prado::getPathOfNamespace($value,self::DB_FILE_EXT))===null)
+			throw new TConfigurationException('sqlitecache_dbfile_invalid',$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)
+	{
+		$sql='SELECT value FROM '.self::CACHE_TABLE.' WHERE key=\''.$key.'\' AND (expire=0 OR expire>'.time().') LIMIT 1';
+		if(($ret=$this->_db->query($sql))!=false && ($row=$ret->fetch(SQLITE_ASSOC))!==false)
+			return unserialize($row['value']);
+		else
+			return false;
+	}
+
+	/**
+	 * 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)
+	{
+		$expire=($expire<=0)?0:time()+$expire;
+		$sql='REPLACE INTO '.self::CACHE_TABLE.' VALUES(\''.$key.'\',\''.sqlite_escape_string(serialize($value)).'\','.$expire.')';
+		return $this->_db->query($sql)!==false;
+	}
+
+	/**
+	 * 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)
+	{
+		$expire=($expire<=0)?0:time()+$expire;
+		$sql='INSERT INTO '.self::CACHE_TABLE.' VALUES(\''.$key.'\',\''.sqlite_escape_string(serialize($value)).'\','.$expire.')';
+		return @$this->_db->query($sql)!==false;
+	}
+
+	/**
+	 * 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)
+	{
+		$sql='DELETE FROM '.self::CACHE_TABLE.' WHERE key=\''.$key.'\'';
+		return $this->_db->query($sql)!==false;
+	}
+
+	/**
+	 * Deletes all values from cache.
+	 * Be careful of performing this operation if the cache is shared by multiple applications.
+	 */
+	public function flush()
+	{
+		return $this->_db->query('DELETE FROM '.self::CACHE_TABLE)!==false;
+	}
+}
+
diff --git a/lib/prado/framework/Caching/TXCache.php b/lib/prado/framework/Caching/TXCache.php
new file mode 100644
index 0000000..19ae42a
--- /dev/null
+++ b/lib/prado/framework/Caching/TXCache.php
@@ -0,0 +1,128 @@
+<?php
+/**
+ * TXCache class file
+ *
+ * @author Wei Zhuo <weizhuo[at]gmail[dot]com>
+ * @link https://github.com/pradosoft/prado
+ * @copyright Copyright &copy; 2005-2015 The PRADO Group
+ * @license https://github.com/pradosoft/prado/blob/master/COPYRIGHT
+ * @package System.Caching
+ */
+
+/**
+ * TXCache class
+ *
+ * TXCache implements a cache application module based on {@link http://xcache.lighttpd.net/ xcache}.
+ *
+ * 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.
+ *
+ * To use this module, the xcache PHP extension must be loaded and configured in the php.ini.
+ *
+ * Some usage examples of TXCache are as follows,
+ * <code>
+ * $cache=new TXCache;  // TXCache may also be loaded as a Prado application module
+ * $cache->init(null);
+ * $cache->add('object',$object);
+ * $object2=$cache->get('object');
+ * </code>
+ *
+ * If loaded, TXCache will register itself with {@link TApplication} as the
+ * cache module. It can be accessed via {@link TApplication::getCache()}.
+ *
+ * TXCache may be configured in application configuration file as follows
+ * <code>
+ * <module id="cache" class="System.Caching.TXCache" />
+ * </code>
+ *
+ * @author Wei Zhuo <weizhuo[at]gmail[dot]com>
+ * @package System.Caching
+ * @since 3.1.1
+ */
+class TXCache extends TCache
+{
+   /**
+    * Initializes this module.
+    * This method is required by the IModule interface.
+    * @param TXmlElement configuration for this module, can be null
+    * @throws TConfigurationException if xcache extension is not installed or not started, check your php.ini
+    */
+	public function init($config)
+	{
+		if(!function_exists('xcache_isset'))
+			throw new TConfigurationException('xcache_extension_required');
+
+		$enabled = (int)ini_get('xcache.cacher') !== 0;
+		$var_size = (int)ini_get('xcache.var_size');
+
+		if(!($enabled && $var_size > 0))
+			throw new TConfigurationException('xcache_extension_not_enabled');
+
+		parent::init($config);
+	}
+
+	/**
+	 * 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($key)
+	{
+		return xcache_isset($key) ? xcache_get($key) : false;
+	}
+
+	/**
+	 * Stores a value identified by a key in cache.
+	 * This is the implementation of the method declared in the parent class.
+	 *
+	 * @param string the key identifying the value to be cached
+	 * @param string the value to be cached
+	 * @param integer the number of seconds in which the cached value will expire. 0 means never expire.
+	 * @return boolean true if the value is successfully stored into cache, false otherwise
+	 */
+	protected function setValue($key,$value,$expire)
+	{
+		return xcache_set($key,$value,$expire);
+	}
+
+	/**
+	 * Stores a value identified by a key into cache if the cache does not contain this key.
+	 * This is the implementation of the method declared in the parent class.
+	 *
+	 * @param string the key identifying the value to be cached
+	 * @param string the value to be cached
+	 * @param integer the number of seconds in which the cached value will expire. 0 means never expire.
+	 * @return boolean true if the value is successfully stored into cache, false otherwise
+	 */
+	protected function addValue($key,$value,$expire)
+	{
+		return !xcache_isset($key) ? $this->setValue($key,$value,$expire) : false;
+	}
+
+	/**
+	 * 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($key)
+	{
+		return xcache_unset($key);
+	}
+
+	/**
+	 * Deletes all values from cache.
+	 * Be careful of performing this operation if the cache is shared by multiple applications.
+	 */
+	public function flush()
+	{
+		for($i=0, $max=xcache_count(XC_TYPE_VAR); $i<$max; $i++)
+		{
+			if(xcache_clear_cache(XC_TYPE_VAR, $i)===false)
+				return false;
+		}
+		return true;
+	}
+}
+