* @link http://www.yiiframework.com/
* @copyright 2008-2013 Yii Software LLC
* @license http://www.yiiframework.com/license/
*/
/**
* CDbHttpSession extends {@link CHttpSession} by using database as session data storage.
*
* CDbHttpSession stores session data in a DB table named 'YiiSession'. The table name
* can be changed by setting {@link sessionTableName}. If the table does not exist,
* it will be automatically created if {@link autoCreateSessionTable} is set true.
*
* The following is the table structure:
*
*
* CREATE TABLE YiiSession
* (
* id CHAR(32) PRIMARY KEY,
* expire INTEGER,
* data BLOB
* )
*
* Where 'BLOB' refers to the BLOB-type of your preffered database.
*
* Note that if your session IDs are more than 32 characters (can be changed via
* session.hash_bits_per_character or session.hash_function) you should modify
* SQL schema accordingly.
*
* CDbHttpSession relies on {@link http://www.php.net/manual/en/ref.pdo.php PDO} to access database.
*
* By default, it will use an SQLite3 database named 'session-YiiVersion.db' under the application runtime directory.
* You can also specify {@link connectionID} so that it makes use of a DB application component to access database.
*
* When using CDbHttpSession in a production server, we recommend you pre-create the session DB table
* and set {@link autoCreateSessionTable} to be false. This will greatly improve the performance.
* You may also create a DB index for the 'expire' column in the session table to further improve the performance.
*
* @property boolean $useCustomStorage Whether to use custom storage.
*
* @author Qiang Xue
* @package system.web
* @since 1.0
*/
class CDbHttpSession extends CHttpSession
{
/**
* @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='YiiSession';
/**
* @var boolean whether the session DB table should be automatically created if not exists. Defaults to true.
* @see sessionTableName
*/
public $autoCreateSessionTable=true;
/**
* @var CDbConnection 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 {@link http://php.net/session_regenerate_id} for more details.
* @param boolean $deleteOldSession Whether to delete the old associated session file or not.
* @since 1.1.8
*/
public function regenerateID($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->getDbConnection();
$row=$db->createCommand()
->select()
->from($this->sessionTableName)
->where('id=:id',array(':id'=>$oldID))
->queryRow();
if($row!==false)
{
if($deleteOldSession)
$db->createCommand()->update($this->sessionTableName,array(
'id'=>$newID
),'id=:oldID',array(':oldID'=>$oldID));
else
{
$row['id']=$newID;
$db->createCommand()->insert($this->sessionTableName, $row);
}
}
else
{
// shouldn't reach here normally
$db->createCommand()->insert($this->sessionTableName, array(
'id'=>$newID,
'expire'=>time()+$this->getTimeout(),
'data'=>'',
));
}
}
/**
* Creates the session DB table.
* @param CDbConnection $db the database connection
* @param string $tableName the name of the table to be created
*/
protected function createSessionTable($db,$tableName)
{
switch($db->getDriverName())
{
case 'mysql':
$blob='LONGBLOB';
break;
case 'pgsql':
$blob='BYTEA';
break;
case 'sqlsrv':
case 'mssql':
case 'dblib':
$blob='VARBINARY(MAX)';
break;
default:
$blob='BLOB';
break;
}
$db->createCommand()->createTable($tableName,array(
'id'=>'CHAR(32) PRIMARY KEY',
'expire'=>'integer',
'data'=>$blob,
));
}
/**
* @return CDbConnection the DB connection instance
* @throws CException if {@link connectionID} does not point to a valid application component.
*/
protected function getDbConnection()
{
if($this->_db!==null)
return $this->_db;
elseif(($id=$this->connectionID)!==null)
{
if(($this->_db=Yii::app()->getComponent($id)) instanceof CDbConnection)
return $this->_db;
else
throw new CException(Yii::t('yii','CDbHttpSession.connectionID "{id}" is invalid. Please make sure it refers to the ID of a CDbConnection application component.',
array('{id}'=>$id)));
}
else
{
$dbFile=Yii::app()->getRuntimePath().DIRECTORY_SEPARATOR.'session-'.Yii::getVersion().'.db';
return $this->_db=new CDbConnection('sqlite:'.$dbFile);
}
}
/**
* Session open handler.
* Do not call this method directly.
* @param string $savePath session save path
* @param string $sessionName session name
* @return boolean whether session is opened successfully
*/
public function openSession($savePath,$sessionName)
{
if($this->autoCreateSessionTable)
{
$db=$this->getDbConnection();
$db->setActive(true);
try
{
$db->createCommand()->delete($this->sessionTableName,'expire<:expire',array(':expire'=>time()));
}
catch(Exception $e)
{
$this->createSessionTable($db,$this->sessionTableName);
}
}
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)
{
$db=$this->getDbConnection();
if($db->getDriverName()=='sqlsrv' || $db->getDriverName()=='mssql' || $db->getDriverName()=='dblib')
$select='CONVERT(VARCHAR(MAX), data)';
else
$select='data';
$data=$db->createCommand()
->select($select)
->from($this->sessionTableName)
->where('expire>:expire AND id=:id',array(':expire'=>time(),':id'=>$id))
->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->getDbConnection();
if($db->getDriverName()=='pgsql' )
$data=new CDbExpression("convert_to(".$db->quoteValue($data).", 'UTF8')");
if($db->getDriverName()=='sqlsrv' || $db->getDriverName()=='mssql' || $db->getDriverName()=='dblib')
$data=new CDbExpression('CONVERT(VARBINARY(MAX), '.$db->quoteValue($data).')');
if($db->createCommand()->select('id')->from($this->sessionTableName)->where('id=:id',array(':id'=>$id))->queryScalar()===false)
$db->createCommand()->insert($this->sessionTableName,array(
'id'=>$id,
'data'=>$data,
'expire'=>$expire,
));
else
$db->createCommand()->update($this->sessionTableName,array(
'data'=>$data,
'expire'=>$expire
),'id=:id',array(':id'=>$id));
}
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)
{
$this->getDbConnection()->createCommand()
->delete($this->sessionTableName,'id=:id',array(':id'=>$id));
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)
{
$this->getDbConnection()->createCommand()
->delete($this->sessionTableName,'expire<:expire',array(':expire'=>time()));
return true;
}
}