framework/web/DbSession.php
<?php
/**
* @link https://www.yiiframework.com/
* @copyright Copyright (c) 2008 Yii Software LLC
* @license https://www.yiiframework.com/license/
*/
namespace yii\web;
use Yii;
use yii\base\InvalidConfigException;
use yii\db\Connection;
use yii\db\PdoValue;
use yii\db\Query;
use yii\di\Instance;
/**
* DbSession extends [[Session]] by using database as session data storage.
*
* By default, DbSession stores session data in a DB table named 'session'. This table
* must be pre-created. The table name can be changed by setting [[sessionTable]].
*
* The following example shows how you can configure the application to use DbSession:
* Add the following to your application config under `components`:
*
* ```php
* 'session' => [
* 'class' => 'yii\web\DbSession',
* // 'db' => 'mydb',
* // 'sessionTable' => 'my_session',
* ]
* ```
*
* DbSession extends [[MultiFieldSession]], thus it allows saving extra fields into the [[sessionTable]].
* Refer to [[MultiFieldSession]] for more details.
*
* @author Qiang Xue <qiang.xue@gmail.com>
* @since 2.0
*/
class DbSession extends MultiFieldSession
{
/**
* @var Connection|array|string the DB connection object or the application component ID of the DB connection.
* After the DbSession object is created, if you want to change this property, you should only assign it
* with a DB connection object.
* Starting from version 2.0.2, this can also be a configuration array for creating the object.
*/
public $db = 'db';
/**
* @var string the name of the DB table that stores the session data.
* The table should be pre-created as follows:
*
* ```sql
* CREATE TABLE session
* (
* id CHAR(40) NOT NULL PRIMARY KEY,
* expire INTEGER,
* data BLOB
* )
* ```
*
* where 'BLOB' refers to the BLOB-type of your preferred DBMS. Below are the BLOB type
* that can be used for some popular DBMS:
*
* - MySQL: LONGBLOB
* - PostgreSQL: BYTEA
* - MSSQL: BLOB
*
* When using DbSession in a production server, we recommend you create a DB index for the 'expire'
* column in the session table to improve the performance.
*
* Note that according to the php.ini setting of `session.hash_function`, you may need to adjust
* the length of the `id` column. For example, if `session.hash_function=sha256`, you should use
* length 64 instead of 40.
*/
public $sessionTable = '{{%session}}';
/**
* @var array Session fields to be written into session table columns
* @since 2.0.17
*/
protected $fields = [];
/**
* Initializes the DbSession component.
* This method will initialize the [[db]] property to make sure it refers to a valid DB connection.
* @throws InvalidConfigException if [[db]] is invalid.
*/
public function init()
{
parent::init();
$this->db = Instance::ensure($this->db, Connection::className());
}
/**
* Session open handler.
* @internal Do not call this method directly.
* @param string $savePath session save path
* @param string $sessionName session name
* @return bool whether session is opened successfully
*/
public function openSession($savePath, $sessionName)
{
if ($this->getUseStrictMode()) {
$id = $this->getId();
if (!$this->getReadQuery($id)->exists($this->db)) {
//This session id does not exist, mark it for forced regeneration
$this->_forceRegenerateId = $id;
}
}
return parent::openSession($savePath, $sessionName);
}
/**
* {@inheritdoc}
*/
public function regenerateID($deleteOldSession = false)
{
$oldID = session_id();
// if no session is started, there is nothing to regenerate
if (empty($oldID)) {
return;
}
parent::regenerateID(false);
$newID = session_id();
// if session id regeneration failed, no need to create/update it.
if (empty($newID)) {
Yii::warning('Failed to generate new session ID', __METHOD__);
return;
}
$row = $this->db->useMaster(function () use ($oldID) {
return (new Query())->from($this->sessionTable)
->where(['id' => $oldID])
->createCommand($this->db)
->queryOne();
});
if ($row !== false && $this->getIsActive()) {
if ($deleteOldSession) {
$this->db->createCommand()
->update($this->sessionTable, ['id' => $newID], ['id' => $oldID])
->execute();
} else {
$row['id'] = $newID;
$this->db->createCommand()
->insert($this->sessionTable, $row)
->execute();
}
}
}
/**
* Ends the current session and store session data.
* @since 2.0.17
*/
public function close()
{
if ($this->getIsActive()) {
// prepare writeCallback fields before session closes
$this->fields = $this->composeFields();
YII_DEBUG ? session_write_close() : @session_write_close();
}
}
/**
* Session read handler.
* @internal Do not call this method directly.
* @param string $id session ID
* @return string the session data
*/
public function readSession($id)
{
$query = $this->getReadQuery($id);
if ($this->readCallback !== null) {
$fields = $query->one($this->db);
return $fields === false ? '' : $this->extractData($fields);
}
$data = $query->select(['data'])->scalar($this->db);
return $data === false ? '' : $data;
}
/**
* Session write handler.
* @internal Do not call this method directly.
* @param string $id session ID
* @param string $data session data
* @return bool whether session write is successful
*/
public function writeSession($id, $data)
{
if ($this->getUseStrictMode() && $id === $this->_forceRegenerateId) {
//Ignore write when forceRegenerate is active for this id
return true;
}
// exception must be caught in session write handler
// https://www.php.net/manual/en/function.session-set-save-handler.php#refsect1-function.session-set-save-handler-notes
try {
// ensure backwards compatability (fixed #9438)
if ($this->writeCallback && !$this->fields) {
$this->fields = $this->composeFields();
}
// ensure data consistency
if (!isset($this->fields['data'])) {
$this->fields['data'] = $data;
} else {
$_SESSION = $this->fields['data'];
}
// ensure 'id' and 'expire' are never affected by [[writeCallback]]
$this->fields = array_merge($this->fields, [
'id' => $id,
'expire' => time() + $this->getTimeout(),
]);
$this->fields = $this->typecastFields($this->fields);
$this->db->createCommand()->upsert($this->sessionTable, $this->fields)->execute();
$this->fields = [];
} catch (\Exception $e) {
Yii::$app->errorHandler->handleException($e);
return false;
}
return true;
}
/**
* Session destroy handler.
* @internal Do not call this method directly.
* @param string $id session ID
* @return bool whether session is destroyed successfully
*/
public function destroySession($id)
{
$this->db->createCommand()
->delete($this->sessionTable, ['id' => $id])
->execute();
return true;
}
/**
* Session GC (garbage collection) handler.
* @internal Do not call this method directly.
* @param int $maxLifetime the number of seconds after which data will be seen as 'garbage' and cleaned up.
* @return bool whether session is GCed successfully
*/
public function gcSession($maxLifetime)
{
$this->db->createCommand()
->delete($this->sessionTable, '[[expire]]<:expire', [':expire' => time()])
->execute();
return true;
}
/**
* Generates a query to get the session from db
* @param string $id The id of the session
* @return Query
*/
protected function getReadQuery($id)
{
return (new Query())
->from($this->sessionTable)
->where('[[expire]]>:expire AND [[id]]=:id', [':expire' => time(), ':id' => $id]);
}
/**
* Method typecasts $fields before passing them to PDO.
* Default implementation casts field `data` to `\PDO::PARAM_LOB`.
* You can override this method in case you need special type casting.
*
* @param array $fields Fields, that will be passed to PDO. Key - name, Value - value
* @return array
* @since 2.0.13
*/
protected function typecastFields($fields)
{
if (isset($fields['data']) && !is_array($fields['data']) && !is_object($fields['data'])) {
$fields['data'] = new PdoValue($fields['data'], \PDO::PARAM_LOB);
}
return $fields;
}
}