* @since 2.0
*/
class DbSession extends Session
{
/**
* @var string the ID of a {@link CDbConnection} application component. If not set, a SQLite database
* will be automatically created and used. The SQLite database file is
* is protected/runtime/session-YiiVersion.db.
*/
public $connectionID;
/**
* @var string the name of the DB table to store session content.
* Note, if {@link autoCreateSessionTable} 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:
*
* (id CHAR(32) PRIMARY KEY, expire INTEGER, data BLOB)
*
* @see autoCreateSessionTable
*/
public $sessionTableName = 'tbl_session';
/**
* @var Connection the DB connection instance
*/
private $_db;
/**
* 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;
}
/**
* Updates the current session ID with a newly generated one .
* Please refer to [[http://php.net/session_regenerate_id]] for more details.
* @param boolean $deleteOldSession Whether to delete the old associated session file or not.
*/
public function regenerateID($deleteOldSession = false)
{
$oldID = session_id();
// if no session is started, there is nothing to regenerate
if (empty($oldID)) {
return;
}
parent::regenerateID(false);
$newID = session_id();
$db = $this->getDb();
$query = new Query;
$row = $query->from($this->sessionTableName)
->where(array('id' => $oldID))
->createCommand($db)
->queryRow();
if ($row !== false) {
if ($deleteOldSession) {
$db->createCommand()->update($this->sessionTableName, array(
'id' => $newID
), array('id' => $oldID))->execute();
} else {
$row['id'] = $newID;
$db->createCommand()->insert($this->sessionTableName, $row)->execute();
}
} else {
// shouldn't reach here normally
$db->createCommand()->insert($this->sessionTableName, array(
'id' => $newID,
'expire' => time() + $this->getTimeout(),
))->execute();
}
}
/**
* Returns the DB connection instance used for storing session data.
* @return Connection the DB connection instance
* @throws InvalidConfigException if [[connectionID]] does not point to a valid application component.
*/
public function getDb()
{
if ($this->_db === null) {
$db = Yii::$app->getComponent($this->connectionID);
if ($db instanceof Connection) {
$this->_db = $db;
} else {
throw new InvalidConfigException("DbSession::connectionID must refer to the ID of a DB application component.");
}
}
return $this->_db;
}
/**
* Sets the DB connection used by the session component.
* @param Connection $value the DB connection instance
*/
public function setDb($value)
{
$this->_db = $value;
}
/**
* Session read handler.
* Do not call this method directly.
* @param string $id session ID
* @return string the session data
*/
public function readSession($id)
{
$query = new Query;
$data = $query->select(array('data'))
->from($this->sessionTableName)
->where('expire>:expire AND id=:id', array(':expire' => time(), ':id' => $id))
->createCommand($this->getDb())
->queryScalar();
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)
{
// exception must be caught in session write handler
// http://us.php.net/manual/en/function.session-set-save-handler.php
try {
$expire = time() + $this->getTimeout();
$db = $this->getDb();
$query = new Query;
$exists = $query->select(array('id'))
->from($this->sessionTableName)
->where(array('id' => $id))
->createCommand($db)
->queryScalar();
if ($exists === false) {
$db->createCommand()->insert($this->sessionTableName, array(
'id' => $id,
'data' => $data,
'expire' => $expire,
))->execute();
} else {
$db->createCommand()->update($this->sessionTableName, array(
'data' => $data,
'expire' => $expire
), array('id' => $id))->execute();
}
} catch (\Exception $e) {
if (YII_DEBUG) {
echo $e->getMessage();
}
// it is too late to log an error message here
return false;
}
return true;
}
/**
* 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)
{
$this->getDb()->createCommand()
->delete($this->sessionTableName, array('id' => $id))
->execute();
return true;
}
/**
* Session GC (garbage collection) handler.
* Do not call this method directly.
* @param integer $maxLifetime the number of seconds after which data will be seen as 'garbage' and cleaned up.
* @return boolean whether session is GCed successfully
*/
public function gcSession($maxLifetime)
{
$this->getDb()->createCommand()
->delete($this->sessionTableName, 'expire<:expire', array(':expire' => time()))
->execute();
return true;
}
}