Finished more caching components.

framework/caching/DummyCache.php

@@ -1,6 +1,6 @@
 <?php
 /**
- * CDummyCache class file.
+ * DummyCache class file.
  *
  * @link http://www.yiiframework.com/
  * @copyright Copyright &copy; 2008-2012 Yii Software LLC
@@ -10,154 +10,74 @@
 namespace yii\caching;
 
 /**
- * CDummyCache is a placeholder cache component.
+ * DummyCache is a placeholder cache component.
  *
- * CDummyCache does not cache anything. It is provided so that one can always configure
- * a 'cache' application component and he does not need to check if \Yii::$application->cache is null or not.
- * By replacing CDummyCache with some other cache component, one can quickly switch from
+ * DummyCache does not cache anything. It is provided so that one can always configure
+ * a 'cache' application component and save the check of existence of `\Yii::$application->cache`.
+ * By replacing DummyCache with some other cache component, one can quickly switch from
  * non-caching mode to caching mode.
  *
  * @author Qiang Xue <qiang.xue@gmail.com>
  * @since 2.0
  */
-class CDummyCache extends CApplicationComponent implements ICache, ArrayAccess
+class DummyCache extends Cache
 {
-	/**
-	 * @var string a string prefixed to every cache key so that it is unique. Defaults to {@link CApplication::getId() application ID}.
-	 */
-	public $keyPrefix;
-
-	/**
-	 * Initializes the application component.
-	 * This method overrides the parent implementation by setting default cache key prefix.
-	 */
-	public function init()
-	{
-		parent::init();
-		if($this->keyPrefix===null)
-			$this->keyPrefix=\Yii::$application->getId();
-	}
-
 	/**
 	 * Retrieves a value from cache with a specified key.
-	 * @param string $id a key identifying the cached value
-	 * @return mixed the value stored in cache, false if the value is not in the cache, expired or the dependency has changed.
+	 * This is the implementation of the method declared in the parent class.
+	 * @param string $key a unique key identifying the cached value
+	 * @return string the value stored in cache, false if the value is not in the cache or expired.
 	 */
-	public function get($id)
+	protected function getValue($key)
 	{
 		return false;
 	}
 
 	/**
-	 * Retrieves multiple values from cache with the specified keys.
-	 * Some caches (such as memcache, apc) allow retrieving multiple cached values at one time,
-	 * which may improve the performance since it reduces the communication cost.
-	 * In case a cache doesn't support this feature natively, it will be simulated by this method.
-	 * @param array $ids list of keys identifying the cached values
-	 * @return array list of cached values corresponding to the specified keys. The array
-	 * is returned in terms of (key,value) pairs.
-	 * If a value is not cached or expired, the corresponding array value will be false.
-	 */
-	public function mget($ids)
-	{
-		$results=array();
-		foreach($ids as $id)
-			$results[$id]=false;
-		return $results;
-	}
-
-	/**
-	 * 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.
+	 * Stores a value identified by a key in cache.
+	 * This is the implementation of the method declared in the parent class.
 	 *
-	 * @param string $id the key identifying the value to be cached
-	 * @param mixed $value the value to be cached
+	 * @param string $key the key identifying the value to be cached
+	 * @param string $value the value to be cached
 	 * @param integer $expire the number of seconds in which the cached value will expire. 0 means never expire.
-	 * @param ICacheDependency $dependency dependency of the cached item. If the dependency changes, the item is labeled invalid.
 	 * @return boolean true if the value is successfully stored into cache, false otherwise
 	 */
-	public function set($id,$value,$expire=0,$dependency=null)
+	protected function setValue($key, $value, $expire)
 	{
 		return true;
 	}
 
 	/**
 	 * 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.
-	 * @param string $id the key identifying the value to be cached
-	 * @param mixed $value the value to be cached
+	 * This is the implementation of the method declared in the parent class.
+	 * @param string $key the key identifying the value to be cached
+	 * @param string $value the value to be cached
 	 * @param integer $expire the number of seconds in which the cached value will expire. 0 means never expire.
-	 * @param ICacheDependency $dependency dependency of the cached item. If the dependency changes, the item is labeled invalid.
 	 * @return boolean true if the value is successfully stored into cache, false otherwise
 	 */
-	public function add($id,$value,$expire=0,$dependency=null)
+	protected function addValue($key, $value, $expire)
 	{
 		return true;
 	}
 
 	/**
 	 * Deletes a value with the specified key from cache
-	 * @param string $id the key of the value to be deleted
+	 * This is the implementation of the method declared in the parent class.
+	 * @param string $key the key of the value to be deleted
 	 * @return boolean if no error happens during deletion
 	 */
-	public function delete($id)
+	protected function deleteValue($key)
 	{
 		return true;
 	}
 
 	/**
 	 * Deletes all values from cache.
-	 * Be careful of performing this operation if the cache is shared by multiple applications.
+	 * This is the implementation of the method declared in the parent class.
 	 * @return boolean whether the flush operation was successful.
-	 * @throws CException if this method is not overridden by child classes
 	 */
-	public function flush()
+	protected function flushValues()
 	{
 		return true;
 	}
-
-	/**
-	 * Returns whether there is a cache entry with a specified key.
-	 * This method is required by the interface ArrayAccess.
-	 * @param string $id a key identifying the cached value
-	 * @return boolean
-	 */
-	public function offsetExists($id)
-	{
-		return false;
-	}
-
-	/**
-	 * Retrieves the value from cache with a specified key.
-	 * This method is required by the interface ArrayAccess.
-	 * @param string $id a key identifying the cached value
-	 * @return mixed the value stored in cache, false if the value is not in the cache or expired.
-	 */
-	public function offsetGet($id)
-	{
-		return false;
-	}
-
-	/**
-	 * 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 $id the key identifying the value to be cached
-	 * @param mixed $value the value to be cached
-	 */
-	public function offsetSet($id, $value)
-	{
-	}
-
-	/**
-	 * Deletes the value with the specified key from cache
-	 * This method is required by the interface ArrayAccess.
-	 * @param string $id the key of the value to be deleted
-	 * @return boolean if no error happens during deletion
-	 */
-	public function offsetUnset($id)
-	{
-	}
 }