1 files changed, 113 insertions, 0 deletions
diff --git a/framework/web/CCacheHttpSession.php b/framework/web/CCacheHttpSession.php
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+<?php
+/**
+ * CCacheHttpSession class
+ *
+ * @author Qiang Xue <qiang.xue@gmail.com>
+ * @link http://www.yiiframework.com/
+ * @copyright Copyright &copy; 2008-2011 Yii Software LLC
+ * @license http://www.yiiframework.com/license/
+ */
+
+
+/**
+ * CCacheHttpSession implements a session component using cache as storage medium.
+ *
+ * The cache being used can be any cache application component implementing {@link ICache} interface.
+ * The ID of the cache application component is specified via {@link cacheID}, which defaults to 'cache'.
+ *
+ * Beware, by definition cache storage are volatile, which means the data stored on them
+ * may be swapped out and get lost. Therefore, you must make sure the cache used by this component
+ * is NOT volatile. If you want to use {@link CDbCache} as storage medium, use {@link CDbHttpSession}
+ * is a better choice.
+ *
+ * @property boolean $useCustomStorage Whether to use custom storage.
+ *
+ * @author Qiang Xue <qiang.xue@gmail.com>
+ * @version $Id: CCacheHttpSession.php 3426 2011-10-25 00:01:09Z alexander.makarow $
+ * @package system.web
+ * @since 1.0
+ */
+class CCacheHttpSession extends CHttpSession
+{
+	/**
+	 * Prefix to the keys for storing cached data
+	 */
+	const CACHE_KEY_PREFIX='Yii.CCacheHttpSession.';
+	/**
+	 * @var string the ID of the cache application component. Defaults to 'cache' (the primary cache application component.)
+	 */
+	public $cacheID='cache';
+
+	/**
+	 * @var ICache the cache component
+	 */
+	private $_cache;
+
+	/**
+	 * Initializes the application component.
+	 * This method overrides the parent implementation by checking if cache is available.
+	 */
+	public function init()
+	{
+		$this->_cache=Yii::app()->getComponent($this->cacheID);
+		if(!($this->_cache instanceof ICache))
+			throw new CException(Yii::t('yii','CCacheHttpSession.cacheID is invalid. Please make sure "{id}" refers to a valid cache application component.',
+				array('{id}'=>$this->cacheID)));
+		parent::init();
+	}
+
+	/**
+	 * Returns a value indicating whether to use custom session storage.
+	 * This method overrides the parent implementation and always returns true.
+	 * @return boolean whether to use custom storage.
+	 */
+	public function getUseCustomStorage()
+	{
+		return true;
+	}
+
+	/**
+	 * Session read handler.
+	 * Do not call this method directly.
+	 * @param string $id session ID
+	 * @return string the session data
+	 */
+	public function readSession($id)
+	{
+		$data=$this->_cache->get($this->calculateKey($id));
+		return $data===false?'':$data;
+	}
+
+	/**
+	 * Session write handler.
+	 * Do not call this method directly.
+	 * @param string $id session ID
+	 * @param string $data session data
+	 * @return boolean whether session write is successful
+	 */
+	public function writeSession($id,$data)
+	{
+		return $this->_cache->set($this->calculateKey($id),$data,$this->getTimeout());
+	}
+
+	/**
+	 * Session destroy handler.
+	 * Do not call this method directly.
+	 * @param string $id session ID
+	 * @return boolean whether session is destroyed successfully
+	 */
+	public function destroySession($id)
+	{
+	    return $this->_cache->delete($this->calculateKey($id));
+	}
+
+	/**
+	 * Generates a unique key used for storing session data in cache.
+	 * @param string $id session variable name
+	 * @return string a safe cache key associated with the session variable name
+	 */
+	protected function calculateKey($id)
+	{
+	    return self::CACHE_KEY_PREFIX.$id;
+	}
+}