/** * Retrieves a value from cache with a specified key. * @param string $id a key identifying the cached value * @return mixed the value stored in cache, false if the value is not in the cache, expired or the dependency has changed. */ public function get($id) { if(($value=$this->getValue($this->generateUniqueKey($id)))!==false) { $data=unserialize($value); if(!is_array($data)) return false; if(!($data[1] instanceof ICacheDependency) || !$data[1]->getHasChanged()) { Yii::trace('Serving "'.$id.'" from cache','system.caching.'.get_class($this)); return $data[0]; } } 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 $ids list of keys identifying the cached values * @return array list of cached values corresponding to the specified keys. The array * is returned in terms of (key,value) pairs. * If a value is not cached or expired, the corresponding array value will be false. * @since 1.0.8 */ public function mget($ids) { $uniqueIDs=array(); $results=array(); foreach($ids as $id) { $uniqueIDs[$id]=$this->generateUniqueKey($id); $results[$id]=false; } $values=$this->getValues($uniqueIDs); foreach($uniqueIDs as $id=>$uniqueID) { if(!isset($values[$uniqueID])) continue; $data=unserialize($values[$uniqueID]); if(is_array($data) && (!($data[1] instanceof ICacheDependency) || !$data[1]->getHasChanged())) { Yii::trace('Serving "'.$id.'" from cache','system.caching.'.get_class($this)); $results[$id]=$data[0]; } } 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. * * @param string $id the key identifying the value to be cached * @param mixed $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,$dependency=null) { Yii::trace('Saving "'.$id.'" to cache','system.caching.'.get_class($this)); if($dependency!==null) $dependency->evaluateDependency(); $data=array($value,$dependency); return $this->setValue($this->generateUniqueKey($id),serialize($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. * @param string $id the key identifying the value to be cached * @param mixed $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,$dependency=null) { Yii::trace('Adding "'.$id.'" to cache','system.caching.'.get_class($this)); if($dependency!==null) $dependency->evaluateDependency(); $data=array($value,$dependency); return $this->addValue($this->generateUniqueKey($id),serialize($data),$expire); } /** * Deletes a value with the specified key from cache * @param string $id the key of the value to be deleted * @return boolean if no error happens during deletion */ public function delete($id) { Yii::trace('Deleting "'.$id.'" from cache','system.caching.'.get_class($this)); return $this->deleteValue($this->generateUniqueKey($id)); } /** * Deletes all values from cache. * Be careful of performing this operation if the cache is shared by multiple applications. * @return boolean whether the flush operation was successful. */ public function flush() { Yii::trace('Flushing cache','system.caching.'.get_class($this)); return $this->flushValues(); }
即：
Yii::app()->cache->xxx
xxx对应具体的方法。
例如：
$id = 'key1'; $value = 'cache value'; Yii::app()->cache->add($id, $value); var_dump(Yii::app()->cache->get($id));
下面是yii官方给出的几种缓存方式的使用说明，这里就麻木不仁，照搬了
3.缓存的使用:数据缓存
数据缓存
数据缓存即存储一些 PHP 变量到缓存中，以后再从缓存中取出来。出于此目的，缓存组件的基类 CCache 提供了两个最常用的方法： set() 和 get()。
要在缓存中存储一个变量 $value ，我们选择一个唯一 ID 并调用 set() 存储它：
Yii::app()->cache->set($id, $value);