* session: data persisting within a single user session.
* state persister: data persisting through all requests/sessions (e.g. hit counter).
* cache: volatile and fast storage. It may be used as storage medium for session or state persister.
*
*
* Since server resource is often limited, be cautious if you plan to use CStatePersister
* to store large amount of data. You should also consider using database-based persister
* to improve the throughput.
*
* CStatePersister is a core application component used to store global application state.
* It may be accessed via {@link CApplication::getStatePersister()}.
* page state persistent method based on cache.
*
* @author Qiang Xue
* @since 2.0
*/
class StatePersister extends ApplicationComponent
{
/**
* @var string the file path for keeping the state data. Make sure the directory containing
* the file exists and is writable by the Web server process. If using relative path, also
* make sure the path is correct. You may use a path alias here. If not set, it defaults
* to the `state.bin` file under the application's runtime directory.
*/
public $dataFile;
/**
* Loads state data from persistent storage.
* @return mixed state data. Null if no state data available.
*/
public function load()
{
$dataFile = \Yii::getAlias($this->dataFile);
if (is_file($dataFile) && ($data = file_get_contents($dataFile)) !== false) {
return unserialize($data);
} else {
return null;
}
}
/**
* Saves application state in persistent storage.
* @param mixed $state state data (must be serializable).
*/
public function save($state)
{
file_put_contents(\Yii::getAlias($this->dataFile), serialize($state), LOCK_EX);
}
}