900 lines
36 KiB
PHP
900 lines
36 KiB
PHP
<?php
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/*
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* This file is part of the Symfony package.
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*
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* (c) Fabien Potencier <fabien@symfony.com>
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*
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* For the full copyright and license information, please view the LICENSE
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* file that was distributed with this source code.
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*/
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namespace Symfony\Component\HttpFoundation\Session\Storage\Handler;
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/**
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* Session handler using a PDO connection to read and write data.
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*
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* It works with MySQL, PostgreSQL, Oracle, SQL Server and SQLite and implements
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* different locking strategies to handle concurrent access to the same session.
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* Locking is necessary to prevent loss of data due to race conditions and to keep
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* the session data consistent between read() and write(). With locking, requests
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* for the same session will wait until the other one finished writing. For this
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* reason it's best practice to close a session as early as possible to improve
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* concurrency. PHPs internal files session handler also implements locking.
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*
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* Attention: Since SQLite does not support row level locks but locks the whole database,
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* it means only one session can be accessed at a time. Even different sessions would wait
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* for another to finish. So saving session in SQLite should only be considered for
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* development or prototypes.
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*
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* Session data is a binary string that can contain non-printable characters like the null byte.
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* For this reason it must be saved in a binary column in the database like BLOB in MySQL.
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* Saving it in a character column could corrupt the data. You can use createTable()
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* to initialize a correctly defined table.
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*
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* @see https://php.net/sessionhandlerinterface
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*
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* @author Fabien Potencier <fabien@symfony.com>
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* @author Michael Williams <michael.williams@funsational.com>
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* @author Tobias Schultze <http://tobion.de>
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*/
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class PdoSessionHandler extends AbstractSessionHandler
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{
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/**
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* No locking is done. This means sessions are prone to loss of data due to
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* race conditions of concurrent requests to the same session. The last session
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* write will win in this case. It might be useful when you implement your own
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* logic to deal with this like an optimistic approach.
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*/
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const LOCK_NONE = 0;
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/**
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* Creates an application-level lock on a session. The disadvantage is that the
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* lock is not enforced by the database and thus other, unaware parts of the
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* application could still concurrently modify the session. The advantage is it
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* does not require a transaction.
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* This mode is not available for SQLite and not yet implemented for oci and sqlsrv.
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*/
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const LOCK_ADVISORY = 1;
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/**
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* Issues a real row lock. Since it uses a transaction between opening and
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* closing a session, you have to be careful when you use same database connection
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* that you also use for your application logic. This mode is the default because
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* it's the only reliable solution across DBMSs.
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*/
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const LOCK_TRANSACTIONAL = 2;
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private const MAX_LIFETIME = 315576000;
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/**
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* @var \PDO|null PDO instance or null when not connected yet
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*/
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private $pdo;
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/**
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* @var string|false|null DSN string or null for session.save_path or false when lazy connection disabled
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*/
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private $dsn = false;
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/**
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* @var string Database driver
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*/
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private $driver;
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/**
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* @var string Table name
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*/
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private $table = 'sessions';
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/**
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* @var string Column for session id
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*/
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private $idCol = 'sess_id';
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/**
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* @var string Column for session data
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*/
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private $dataCol = 'sess_data';
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/**
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* @var string Column for lifetime
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*/
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private $lifetimeCol = 'sess_lifetime';
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/**
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* @var string Column for timestamp
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*/
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private $timeCol = 'sess_time';
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/**
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* @var string Username when lazy-connect
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*/
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private $username = '';
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/**
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* @var string Password when lazy-connect
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*/
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private $password = '';
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/**
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* @var array Connection options when lazy-connect
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*/
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private $connectionOptions = [];
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/**
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* @var int The strategy for locking, see constants
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*/
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private $lockMode = self::LOCK_TRANSACTIONAL;
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/**
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* It's an array to support multiple reads before closing which is manual, non-standard usage.
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*
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* @var \PDOStatement[] An array of statements to release advisory locks
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*/
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private $unlockStatements = [];
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/**
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* @var bool True when the current session exists but expired according to session.gc_maxlifetime
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*/
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private $sessionExpired = false;
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/**
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* @var bool Whether a transaction is active
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*/
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private $inTransaction = false;
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/**
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* @var bool Whether gc() has been called
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*/
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private $gcCalled = false;
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/**
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* You can either pass an existing database connection as PDO instance or
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* pass a DSN string that will be used to lazy-connect to the database
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* when the session is actually used. Furthermore it's possible to pass null
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* which will then use the session.save_path ini setting as PDO DSN parameter.
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*
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* List of available options:
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* * db_table: The name of the table [default: sessions]
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* * db_id_col: The column where to store the session id [default: sess_id]
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* * db_data_col: The column where to store the session data [default: sess_data]
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* * db_lifetime_col: The column where to store the lifetime [default: sess_lifetime]
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* * db_time_col: The column where to store the timestamp [default: sess_time]
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* * db_username: The username when lazy-connect [default: '']
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* * db_password: The password when lazy-connect [default: '']
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* * db_connection_options: An array of driver-specific connection options [default: []]
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* * lock_mode: The strategy for locking, see constants [default: LOCK_TRANSACTIONAL]
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*
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* @param \PDO|string|null $pdoOrDsn A \PDO instance or DSN string or URL string or null
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*
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* @throws \InvalidArgumentException When PDO error mode is not PDO::ERRMODE_EXCEPTION
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*/
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public function __construct($pdoOrDsn = null, array $options = [])
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{
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if ($pdoOrDsn instanceof \PDO) {
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if (\PDO::ERRMODE_EXCEPTION !== $pdoOrDsn->getAttribute(\PDO::ATTR_ERRMODE)) {
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throw new \InvalidArgumentException(sprintf('"%s" requires PDO error mode attribute be set to throw Exceptions (i.e. $pdo->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION)).', __CLASS__));
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}
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$this->pdo = $pdoOrDsn;
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$this->driver = $this->pdo->getAttribute(\PDO::ATTR_DRIVER_NAME);
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} elseif (\is_string($pdoOrDsn) && false !== strpos($pdoOrDsn, '://')) {
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$this->dsn = $this->buildDsnFromUrl($pdoOrDsn);
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} else {
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$this->dsn = $pdoOrDsn;
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}
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$this->table = isset($options['db_table']) ? $options['db_table'] : $this->table;
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$this->idCol = isset($options['db_id_col']) ? $options['db_id_col'] : $this->idCol;
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$this->dataCol = isset($options['db_data_col']) ? $options['db_data_col'] : $this->dataCol;
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$this->lifetimeCol = isset($options['db_lifetime_col']) ? $options['db_lifetime_col'] : $this->lifetimeCol;
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$this->timeCol = isset($options['db_time_col']) ? $options['db_time_col'] : $this->timeCol;
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$this->username = isset($options['db_username']) ? $options['db_username'] : $this->username;
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$this->password = isset($options['db_password']) ? $options['db_password'] : $this->password;
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$this->connectionOptions = isset($options['db_connection_options']) ? $options['db_connection_options'] : $this->connectionOptions;
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$this->lockMode = isset($options['lock_mode']) ? $options['lock_mode'] : $this->lockMode;
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}
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/**
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* Creates the table to store sessions which can be called once for setup.
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*
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* Session ID is saved in a column of maximum length 128 because that is enough even
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* for a 512 bit configured session.hash_function like Whirlpool. Session data is
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* saved in a BLOB. One could also use a shorter inlined varbinary column
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* if one was sure the data fits into it.
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*
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* @throws \PDOException When the table already exists
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* @throws \DomainException When an unsupported PDO driver is used
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*/
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public function createTable()
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{
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// connect if we are not yet
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$this->getConnection();
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switch ($this->driver) {
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case 'mysql':
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// We use varbinary for the ID column because it prevents unwanted conversions:
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// - character set conversions between server and client
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// - trailing space removal
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// - case-insensitivity
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// - language processing like é == e
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$sql = "CREATE TABLE $this->table ($this->idCol VARBINARY(128) NOT NULL PRIMARY KEY, $this->dataCol BLOB NOT NULL, $this->lifetimeCol INTEGER UNSIGNED NOT NULL, $this->timeCol INTEGER UNSIGNED NOT NULL) COLLATE utf8mb4_bin, ENGINE = InnoDB";
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break;
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case 'sqlite':
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$sql = "CREATE TABLE $this->table ($this->idCol TEXT NOT NULL PRIMARY KEY, $this->dataCol BLOB NOT NULL, $this->lifetimeCol INTEGER NOT NULL, $this->timeCol INTEGER NOT NULL)";
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break;
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case 'pgsql':
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$sql = "CREATE TABLE $this->table ($this->idCol VARCHAR(128) NOT NULL PRIMARY KEY, $this->dataCol BYTEA NOT NULL, $this->lifetimeCol INTEGER NOT NULL, $this->timeCol INTEGER NOT NULL)";
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break;
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case 'oci':
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$sql = "CREATE TABLE $this->table ($this->idCol VARCHAR2(128) NOT NULL PRIMARY KEY, $this->dataCol BLOB NOT NULL, $this->lifetimeCol INTEGER NOT NULL, $this->timeCol INTEGER NOT NULL)";
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break;
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case 'sqlsrv':
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$sql = "CREATE TABLE $this->table ($this->idCol VARCHAR(128) NOT NULL PRIMARY KEY, $this->dataCol VARBINARY(MAX) NOT NULL, $this->lifetimeCol INTEGER NOT NULL, $this->timeCol INTEGER NOT NULL)";
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break;
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default:
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throw new \DomainException(sprintf('Creating the session table is currently not implemented for PDO driver "%s".', $this->driver));
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}
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try {
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$this->pdo->exec($sql);
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$this->pdo->exec("CREATE INDEX EXPIRY ON $this->table ($this->lifetimeCol)");
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} catch (\PDOException $e) {
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$this->rollback();
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throw $e;
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}
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}
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/**
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* Returns true when the current session exists but expired according to session.gc_maxlifetime.
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*
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* Can be used to distinguish between a new session and one that expired due to inactivity.
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*
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* @return bool Whether current session expired
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*/
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public function isSessionExpired()
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{
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return $this->sessionExpired;
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}
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/**
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* @return bool
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*/
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public function open($savePath, $sessionName)
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{
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$this->sessionExpired = false;
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if (null === $this->pdo) {
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$this->connect($this->dsn ?: $savePath);
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}
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return parent::open($savePath, $sessionName);
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}
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/**
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* @return string
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*/
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public function read($sessionId)
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{
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try {
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return parent::read($sessionId);
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} catch (\PDOException $e) {
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$this->rollback();
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throw $e;
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}
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}
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/**
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* @return bool
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*/
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public function gc($maxlifetime)
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{
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// We delay gc() to close() so that it is executed outside the transactional and blocking read-write process.
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// This way, pruning expired sessions does not block them from being started while the current session is used.
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$this->gcCalled = true;
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return true;
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}
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/**
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* {@inheritdoc}
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*/
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protected function doDestroy(string $sessionId)
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{
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// delete the record associated with this id
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$sql = "DELETE FROM $this->table WHERE $this->idCol = :id";
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try {
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$stmt = $this->pdo->prepare($sql);
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$stmt->bindParam(':id', $sessionId, \PDO::PARAM_STR);
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$stmt->execute();
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} catch (\PDOException $e) {
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$this->rollback();
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throw $e;
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}
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return true;
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}
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/**
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* {@inheritdoc}
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*/
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protected function doWrite(string $sessionId, string $data)
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{
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$maxlifetime = (int) ini_get('session.gc_maxlifetime');
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try {
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// We use a single MERGE SQL query when supported by the database.
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$mergeStmt = $this->getMergeStatement($sessionId, $data, $maxlifetime);
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if (null !== $mergeStmt) {
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$mergeStmt->execute();
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return true;
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}
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$updateStmt = $this->getUpdateStatement($sessionId, $data, $maxlifetime);
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$updateStmt->execute();
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// When MERGE is not supported, like in Postgres < 9.5, we have to use this approach that can result in
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// duplicate key errors when the same session is written simultaneously (given the LOCK_NONE behavior).
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// We can just catch such an error and re-execute the update. This is similar to a serializable
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// transaction with retry logic on serialization failures but without the overhead and without possible
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// false positives due to longer gap locking.
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if (!$updateStmt->rowCount()) {
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try {
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$insertStmt = $this->getInsertStatement($sessionId, $data, $maxlifetime);
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$insertStmt->execute();
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} catch (\PDOException $e) {
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// Handle integrity violation SQLSTATE 23000 (or a subclass like 23505 in Postgres) for duplicate keys
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if (0 === strpos($e->getCode(), '23')) {
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$updateStmt->execute();
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} else {
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throw $e;
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}
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}
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}
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} catch (\PDOException $e) {
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$this->rollback();
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throw $e;
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}
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return true;
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}
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/**
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* @return bool
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*/
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public function updateTimestamp($sessionId, $data)
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{
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$expiry = time() + (int) ini_get('session.gc_maxlifetime');
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try {
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$updateStmt = $this->pdo->prepare(
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"UPDATE $this->table SET $this->lifetimeCol = :expiry, $this->timeCol = :time WHERE $this->idCol = :id"
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);
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$updateStmt->bindParam(':id', $sessionId, \PDO::PARAM_STR);
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$updateStmt->bindParam(':expiry', $expiry, \PDO::PARAM_INT);
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$updateStmt->bindValue(':time', time(), \PDO::PARAM_INT);
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$updateStmt->execute();
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} catch (\PDOException $e) {
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$this->rollback();
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throw $e;
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}
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return true;
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}
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/**
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* @return bool
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*/
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public function close()
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{
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$this->commit();
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while ($unlockStmt = array_shift($this->unlockStatements)) {
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$unlockStmt->execute();
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}
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if ($this->gcCalled) {
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$this->gcCalled = false;
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// delete the session records that have expired
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$sql = "DELETE FROM $this->table WHERE $this->lifetimeCol < :time AND $this->lifetimeCol > :min";
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$stmt = $this->pdo->prepare($sql);
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$stmt->bindValue(':time', time(), \PDO::PARAM_INT);
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$stmt->bindValue(':min', self::MAX_LIFETIME, \PDO::PARAM_INT);
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$stmt->execute();
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// to be removed in 6.0
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if ('mysql' === $this->driver) {
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$legacySql = "DELETE FROM $this->table WHERE $this->lifetimeCol <= :min AND $this->lifetimeCol + $this->timeCol < :time";
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} else {
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$legacySql = "DELETE FROM $this->table WHERE $this->lifetimeCol <= :min AND $this->lifetimeCol < :time - $this->timeCol";
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}
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$stmt = $this->pdo->prepare($legacySql);
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$stmt->bindValue(':time', time(), \PDO::PARAM_INT);
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$stmt->bindValue(':min', self::MAX_LIFETIME, \PDO::PARAM_INT);
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$stmt->execute();
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}
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if (false !== $this->dsn) {
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$this->pdo = null; // only close lazy-connection
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}
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return true;
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}
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/**
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* Lazy-connects to the database.
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*/
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private function connect(string $dsn): void
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{
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$this->pdo = new \PDO($dsn, $this->username, $this->password, $this->connectionOptions);
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$this->pdo->setAttribute(\PDO::ATTR_ERRMODE, \PDO::ERRMODE_EXCEPTION);
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$this->driver = $this->pdo->getAttribute(\PDO::ATTR_DRIVER_NAME);
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}
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/**
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* Builds a PDO DSN from a URL-like connection string.
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*
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* @todo implement missing support for oci DSN (which look totally different from other PDO ones)
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*/
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private function buildDsnFromUrl(string $dsnOrUrl): string
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{
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// (pdo_)?sqlite3?:///... => (pdo_)?sqlite3?://localhost/... or else the URL will be invalid
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$url = preg_replace('#^((?:pdo_)?sqlite3?):///#', '$1://localhost/', $dsnOrUrl);
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$params = parse_url($url);
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if (false === $params) {
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return $dsnOrUrl; // If the URL is not valid, let's assume it might be a DSN already.
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}
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$params = array_map('rawurldecode', $params);
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// Override the default username and password. Values passed through options will still win over these in the constructor.
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if (isset($params['user'])) {
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$this->username = $params['user'];
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}
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if (isset($params['pass'])) {
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$this->password = $params['pass'];
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}
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if (!isset($params['scheme'])) {
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throw new \InvalidArgumentException('URLs without scheme are not supported to configure the PdoSessionHandler.');
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}
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$driverAliasMap = [
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'mssql' => 'sqlsrv',
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'mysql2' => 'mysql', // Amazon RDS, for some weird reason
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'postgres' => 'pgsql',
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'postgresql' => 'pgsql',
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'sqlite3' => 'sqlite',
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];
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$driver = isset($driverAliasMap[$params['scheme']]) ? $driverAliasMap[$params['scheme']] : $params['scheme'];
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// Doctrine DBAL supports passing its internal pdo_* driver names directly too (allowing both dashes and underscores). This allows supporting the same here.
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if (0 === strpos($driver, 'pdo_') || 0 === strpos($driver, 'pdo-')) {
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$driver = substr($driver, 4);
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}
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switch ($driver) {
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case 'mysql':
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case 'pgsql':
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$dsn = $driver.':';
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if (isset($params['host']) && '' !== $params['host']) {
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$dsn .= 'host='.$params['host'].';';
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|
}
|
|
|
|
if (isset($params['port']) && '' !== $params['port']) {
|
|
$dsn .= 'port='.$params['port'].';';
|
|
}
|
|
|
|
if (isset($params['path'])) {
|
|
$dbName = substr($params['path'], 1); // Remove the leading slash
|
|
$dsn .= 'dbname='.$dbName.';';
|
|
}
|
|
|
|
return $dsn;
|
|
|
|
case 'sqlite':
|
|
return 'sqlite:'.substr($params['path'], 1);
|
|
|
|
case 'sqlsrv':
|
|
$dsn = 'sqlsrv:server=';
|
|
|
|
if (isset($params['host'])) {
|
|
$dsn .= $params['host'];
|
|
}
|
|
|
|
if (isset($params['port']) && '' !== $params['port']) {
|
|
$dsn .= ','.$params['port'];
|
|
}
|
|
|
|
if (isset($params['path'])) {
|
|
$dbName = substr($params['path'], 1); // Remove the leading slash
|
|
$dsn .= ';Database='.$dbName;
|
|
}
|
|
|
|
return $dsn;
|
|
|
|
default:
|
|
throw new \InvalidArgumentException(sprintf('The scheme "%s" is not supported by the PdoSessionHandler URL configuration. Pass a PDO DSN directly.', $params['scheme']));
|
|
}
|
|
}
|
|
|
|
/**
|
|
* Helper method to begin a transaction.
|
|
*
|
|
* Since SQLite does not support row level locks, we have to acquire a reserved lock
|
|
* on the database immediately. Because of https://bugs.php.net/42766 we have to create
|
|
* such a transaction manually which also means we cannot use PDO::commit or
|
|
* PDO::rollback or PDO::inTransaction for SQLite.
|
|
*
|
|
* Also MySQLs default isolation, REPEATABLE READ, causes deadlock for different sessions
|
|
* due to https://percona.com/blog/2013/12/12/one-more-innodb-gap-lock-to-avoid/ .
|
|
* So we change it to READ COMMITTED.
|
|
*/
|
|
private function beginTransaction(): void
|
|
{
|
|
if (!$this->inTransaction) {
|
|
if ('sqlite' === $this->driver) {
|
|
$this->pdo->exec('BEGIN IMMEDIATE TRANSACTION');
|
|
} else {
|
|
if ('mysql' === $this->driver) {
|
|
$this->pdo->exec('SET TRANSACTION ISOLATION LEVEL READ COMMITTED');
|
|
}
|
|
$this->pdo->beginTransaction();
|
|
}
|
|
$this->inTransaction = true;
|
|
}
|
|
}
|
|
|
|
/**
|
|
* Helper method to commit a transaction.
|
|
*/
|
|
private function commit(): void
|
|
{
|
|
if ($this->inTransaction) {
|
|
try {
|
|
// commit read-write transaction which also releases the lock
|
|
if ('sqlite' === $this->driver) {
|
|
$this->pdo->exec('COMMIT');
|
|
} else {
|
|
$this->pdo->commit();
|
|
}
|
|
$this->inTransaction = false;
|
|
} catch (\PDOException $e) {
|
|
$this->rollback();
|
|
|
|
throw $e;
|
|
}
|
|
}
|
|
}
|
|
|
|
/**
|
|
* Helper method to rollback a transaction.
|
|
*/
|
|
private function rollback(): void
|
|
{
|
|
// We only need to rollback if we are in a transaction. Otherwise the resulting
|
|
// error would hide the real problem why rollback was called. We might not be
|
|
// in a transaction when not using the transactional locking behavior or when
|
|
// two callbacks (e.g. destroy and write) are invoked that both fail.
|
|
if ($this->inTransaction) {
|
|
if ('sqlite' === $this->driver) {
|
|
$this->pdo->exec('ROLLBACK');
|
|
} else {
|
|
$this->pdo->rollBack();
|
|
}
|
|
$this->inTransaction = false;
|
|
}
|
|
}
|
|
|
|
/**
|
|
* Reads the session data in respect to the different locking strategies.
|
|
*
|
|
* We need to make sure we do not return session data that is already considered garbage according
|
|
* to the session.gc_maxlifetime setting because gc() is called after read() and only sometimes.
|
|
*
|
|
* @return string
|
|
*/
|
|
protected function doRead(string $sessionId)
|
|
{
|
|
if (self::LOCK_ADVISORY === $this->lockMode) {
|
|
$this->unlockStatements[] = $this->doAdvisoryLock($sessionId);
|
|
}
|
|
|
|
$selectSql = $this->getSelectSql();
|
|
$selectStmt = $this->pdo->prepare($selectSql);
|
|
$selectStmt->bindParam(':id', $sessionId, \PDO::PARAM_STR);
|
|
$insertStmt = null;
|
|
|
|
do {
|
|
$selectStmt->execute();
|
|
$sessionRows = $selectStmt->fetchAll(\PDO::FETCH_NUM);
|
|
|
|
if ($sessionRows) {
|
|
$expiry = (int) $sessionRows[0][1];
|
|
if ($expiry <= self::MAX_LIFETIME) {
|
|
$expiry += $sessionRows[0][2];
|
|
}
|
|
|
|
if ($expiry < time()) {
|
|
$this->sessionExpired = true;
|
|
|
|
return '';
|
|
}
|
|
|
|
return \is_resource($sessionRows[0][0]) ? stream_get_contents($sessionRows[0][0]) : $sessionRows[0][0];
|
|
}
|
|
|
|
if (null !== $insertStmt) {
|
|
$this->rollback();
|
|
throw new \RuntimeException('Failed to read session: INSERT reported a duplicate id but next SELECT did not return any data.');
|
|
}
|
|
|
|
if (!filter_var(ini_get('session.use_strict_mode'), FILTER_VALIDATE_BOOLEAN) && self::LOCK_TRANSACTIONAL === $this->lockMode && 'sqlite' !== $this->driver) {
|
|
// In strict mode, session fixation is not possible: new sessions always start with a unique
|
|
// random id, so that concurrency is not possible and this code path can be skipped.
|
|
// Exclusive-reading of non-existent rows does not block, so we need to do an insert to block
|
|
// until other connections to the session are committed.
|
|
try {
|
|
$insertStmt = $this->getInsertStatement($sessionId, '', 0);
|
|
$insertStmt->execute();
|
|
} catch (\PDOException $e) {
|
|
// Catch duplicate key error because other connection created the session already.
|
|
// It would only not be the case when the other connection destroyed the session.
|
|
if (0 === strpos($e->getCode(), '23')) {
|
|
// Retrieve finished session data written by concurrent connection by restarting the loop.
|
|
// We have to start a new transaction as a failed query will mark the current transaction as
|
|
// aborted in PostgreSQL and disallow further queries within it.
|
|
$this->rollback();
|
|
$this->beginTransaction();
|
|
continue;
|
|
}
|
|
|
|
throw $e;
|
|
}
|
|
}
|
|
|
|
return '';
|
|
} while (true);
|
|
}
|
|
|
|
/**
|
|
* Executes an application-level lock on the database.
|
|
*
|
|
* @return \PDOStatement The statement that needs to be executed later to release the lock
|
|
*
|
|
* @throws \DomainException When an unsupported PDO driver is used
|
|
*
|
|
* @todo implement missing advisory locks
|
|
* - for oci using DBMS_LOCK.REQUEST
|
|
* - for sqlsrv using sp_getapplock with LockOwner = Session
|
|
*/
|
|
private function doAdvisoryLock(string $sessionId): \PDOStatement
|
|
{
|
|
switch ($this->driver) {
|
|
case 'mysql':
|
|
// MySQL 5.7.5 and later enforces a maximum length on lock names of 64 characters. Previously, no limit was enforced.
|
|
$lockId = substr($sessionId, 0, 64);
|
|
// should we handle the return value? 0 on timeout, null on error
|
|
// we use a timeout of 50 seconds which is also the default for innodb_lock_wait_timeout
|
|
$stmt = $this->pdo->prepare('SELECT GET_LOCK(:key, 50)');
|
|
$stmt->bindValue(':key', $lockId, \PDO::PARAM_STR);
|
|
$stmt->execute();
|
|
|
|
$releaseStmt = $this->pdo->prepare('DO RELEASE_LOCK(:key)');
|
|
$releaseStmt->bindValue(':key', $lockId, \PDO::PARAM_STR);
|
|
|
|
return $releaseStmt;
|
|
case 'pgsql':
|
|
// Obtaining an exclusive session level advisory lock requires an integer key.
|
|
// When session.sid_bits_per_character > 4, the session id can contain non-hex-characters.
|
|
// So we cannot just use hexdec().
|
|
if (4 === \PHP_INT_SIZE) {
|
|
$sessionInt1 = $this->convertStringToInt($sessionId);
|
|
$sessionInt2 = $this->convertStringToInt(substr($sessionId, 4, 4));
|
|
|
|
$stmt = $this->pdo->prepare('SELECT pg_advisory_lock(:key1, :key2)');
|
|
$stmt->bindValue(':key1', $sessionInt1, \PDO::PARAM_INT);
|
|
$stmt->bindValue(':key2', $sessionInt2, \PDO::PARAM_INT);
|
|
$stmt->execute();
|
|
|
|
$releaseStmt = $this->pdo->prepare('SELECT pg_advisory_unlock(:key1, :key2)');
|
|
$releaseStmt->bindValue(':key1', $sessionInt1, \PDO::PARAM_INT);
|
|
$releaseStmt->bindValue(':key2', $sessionInt2, \PDO::PARAM_INT);
|
|
} else {
|
|
$sessionBigInt = $this->convertStringToInt($sessionId);
|
|
|
|
$stmt = $this->pdo->prepare('SELECT pg_advisory_lock(:key)');
|
|
$stmt->bindValue(':key', $sessionBigInt, \PDO::PARAM_INT);
|
|
$stmt->execute();
|
|
|
|
$releaseStmt = $this->pdo->prepare('SELECT pg_advisory_unlock(:key)');
|
|
$releaseStmt->bindValue(':key', $sessionBigInt, \PDO::PARAM_INT);
|
|
}
|
|
|
|
return $releaseStmt;
|
|
case 'sqlite':
|
|
throw new \DomainException('SQLite does not support advisory locks.');
|
|
default:
|
|
throw new \DomainException(sprintf('Advisory locks are currently not implemented for PDO driver "%s".', $this->driver));
|
|
}
|
|
}
|
|
|
|
/**
|
|
* Encodes the first 4 (when PHP_INT_SIZE == 4) or 8 characters of the string as an integer.
|
|
*
|
|
* Keep in mind, PHP integers are signed.
|
|
*/
|
|
private function convertStringToInt(string $string): int
|
|
{
|
|
if (4 === \PHP_INT_SIZE) {
|
|
return (\ord($string[3]) << 24) + (\ord($string[2]) << 16) + (\ord($string[1]) << 8) + \ord($string[0]);
|
|
}
|
|
|
|
$int1 = (\ord($string[7]) << 24) + (\ord($string[6]) << 16) + (\ord($string[5]) << 8) + \ord($string[4]);
|
|
$int2 = (\ord($string[3]) << 24) + (\ord($string[2]) << 16) + (\ord($string[1]) << 8) + \ord($string[0]);
|
|
|
|
return $int2 + ($int1 << 32);
|
|
}
|
|
|
|
/**
|
|
* Return a locking or nonlocking SQL query to read session information.
|
|
*
|
|
* @throws \DomainException When an unsupported PDO driver is used
|
|
*/
|
|
private function getSelectSql(): string
|
|
{
|
|
if (self::LOCK_TRANSACTIONAL === $this->lockMode) {
|
|
$this->beginTransaction();
|
|
|
|
// selecting the time column should be removed in 6.0
|
|
switch ($this->driver) {
|
|
case 'mysql':
|
|
case 'oci':
|
|
case 'pgsql':
|
|
return "SELECT $this->dataCol, $this->lifetimeCol, $this->timeCol FROM $this->table WHERE $this->idCol = :id FOR UPDATE";
|
|
case 'sqlsrv':
|
|
return "SELECT $this->dataCol, $this->lifetimeCol, $this->timeCol FROM $this->table WITH (UPDLOCK, ROWLOCK) WHERE $this->idCol = :id";
|
|
case 'sqlite':
|
|
// we already locked when starting transaction
|
|
break;
|
|
default:
|
|
throw new \DomainException(sprintf('Transactional locks are currently not implemented for PDO driver "%s".', $this->driver));
|
|
}
|
|
}
|
|
|
|
return "SELECT $this->dataCol, $this->lifetimeCol, $this->timeCol FROM $this->table WHERE $this->idCol = :id";
|
|
}
|
|
|
|
/**
|
|
* Returns an insert statement supported by the database for writing session data.
|
|
*/
|
|
private function getInsertStatement(string $sessionId, string $sessionData, int $maxlifetime): \PDOStatement
|
|
{
|
|
switch ($this->driver) {
|
|
case 'oci':
|
|
$data = fopen('php://memory', 'r+');
|
|
fwrite($data, $sessionData);
|
|
rewind($data);
|
|
$sql = "INSERT INTO $this->table ($this->idCol, $this->dataCol, $this->lifetimeCol, $this->timeCol) VALUES (:id, EMPTY_BLOB(), :expiry, :time) RETURNING $this->dataCol into :data";
|
|
break;
|
|
default:
|
|
$data = $sessionData;
|
|
$sql = "INSERT INTO $this->table ($this->idCol, $this->dataCol, $this->lifetimeCol, $this->timeCol) VALUES (:id, :data, :expiry, :time)";
|
|
break;
|
|
}
|
|
|
|
$stmt = $this->pdo->prepare($sql);
|
|
$stmt->bindParam(':id', $sessionId, \PDO::PARAM_STR);
|
|
$stmt->bindParam(':data', $data, \PDO::PARAM_LOB);
|
|
$stmt->bindValue(':expiry', time() + $maxlifetime, \PDO::PARAM_INT);
|
|
$stmt->bindValue(':time', time(), \PDO::PARAM_INT);
|
|
|
|
return $stmt;
|
|
}
|
|
|
|
/**
|
|
* Returns an update statement supported by the database for writing session data.
|
|
*/
|
|
private function getUpdateStatement(string $sessionId, string $sessionData, int $maxlifetime): \PDOStatement
|
|
{
|
|
switch ($this->driver) {
|
|
case 'oci':
|
|
$data = fopen('php://memory', 'r+');
|
|
fwrite($data, $sessionData);
|
|
rewind($data);
|
|
$sql = "UPDATE $this->table SET $this->dataCol = EMPTY_BLOB(), $this->lifetimeCol = :expiry, $this->timeCol = :time WHERE $this->idCol = :id RETURNING $this->dataCol into :data";
|
|
break;
|
|
default:
|
|
$data = $sessionData;
|
|
$sql = "UPDATE $this->table SET $this->dataCol = :data, $this->lifetimeCol = :expiry, $this->timeCol = :time WHERE $this->idCol = :id";
|
|
break;
|
|
}
|
|
|
|
$stmt = $this->pdo->prepare($sql);
|
|
$stmt->bindParam(':id', $sessionId, \PDO::PARAM_STR);
|
|
$stmt->bindParam(':data', $data, \PDO::PARAM_LOB);
|
|
$stmt->bindValue(':expiry', time() + $maxlifetime, \PDO::PARAM_INT);
|
|
$stmt->bindValue(':time', time(), \PDO::PARAM_INT);
|
|
|
|
return $stmt;
|
|
}
|
|
|
|
/**
|
|
* Returns a merge/upsert (i.e. insert or update) statement when supported by the database for writing session data.
|
|
*/
|
|
private function getMergeStatement(string $sessionId, string $data, int $maxlifetime): ?\PDOStatement
|
|
{
|
|
switch (true) {
|
|
case 'mysql' === $this->driver:
|
|
$mergeSql = "INSERT INTO $this->table ($this->idCol, $this->dataCol, $this->lifetimeCol, $this->timeCol) VALUES (:id, :data, :expiry, :time) ".
|
|
"ON DUPLICATE KEY UPDATE $this->dataCol = VALUES($this->dataCol), $this->lifetimeCol = VALUES($this->lifetimeCol), $this->timeCol = VALUES($this->timeCol)";
|
|
break;
|
|
case 'sqlsrv' === $this->driver && version_compare($this->pdo->getAttribute(\PDO::ATTR_SERVER_VERSION), '10', '>='):
|
|
// MERGE is only available since SQL Server 2008 and must be terminated by semicolon
|
|
// It also requires HOLDLOCK according to https://weblogs.sqlteam.com/dang/2009/01/31/upsert-race-condition-with-merge/
|
|
$mergeSql = "MERGE INTO $this->table WITH (HOLDLOCK) USING (SELECT 1 AS dummy) AS src ON ($this->idCol = ?) ".
|
|
"WHEN NOT MATCHED THEN INSERT ($this->idCol, $this->dataCol, $this->lifetimeCol, $this->timeCol) VALUES (?, ?, ?, ?) ".
|
|
"WHEN MATCHED THEN UPDATE SET $this->dataCol = ?, $this->lifetimeCol = ?, $this->timeCol = ?;";
|
|
break;
|
|
case 'sqlite' === $this->driver:
|
|
$mergeSql = "INSERT OR REPLACE INTO $this->table ($this->idCol, $this->dataCol, $this->lifetimeCol, $this->timeCol) VALUES (:id, :data, :expiry, :time)";
|
|
break;
|
|
case 'pgsql' === $this->driver && version_compare($this->pdo->getAttribute(\PDO::ATTR_SERVER_VERSION), '9.5', '>='):
|
|
$mergeSql = "INSERT INTO $this->table ($this->idCol, $this->dataCol, $this->lifetimeCol, $this->timeCol) VALUES (:id, :data, :expiry, :time) ".
|
|
"ON CONFLICT ($this->idCol) DO UPDATE SET ($this->dataCol, $this->lifetimeCol, $this->timeCol) = (EXCLUDED.$this->dataCol, EXCLUDED.$this->lifetimeCol, EXCLUDED.$this->timeCol)";
|
|
break;
|
|
default:
|
|
// MERGE is not supported with LOBs: https://oracle.com/technetwork/articles/fuecks-lobs-095315.html
|
|
return null;
|
|
}
|
|
|
|
$mergeStmt = $this->pdo->prepare($mergeSql);
|
|
|
|
if ('sqlsrv' === $this->driver) {
|
|
$mergeStmt->bindParam(1, $sessionId, \PDO::PARAM_STR);
|
|
$mergeStmt->bindParam(2, $sessionId, \PDO::PARAM_STR);
|
|
$mergeStmt->bindParam(3, $data, \PDO::PARAM_LOB);
|
|
$mergeStmt->bindValue(4, time() + $maxlifetime, \PDO::PARAM_INT);
|
|
$mergeStmt->bindValue(5, time(), \PDO::PARAM_INT);
|
|
$mergeStmt->bindParam(6, $data, \PDO::PARAM_LOB);
|
|
$mergeStmt->bindValue(7, time() + $maxlifetime, \PDO::PARAM_INT);
|
|
$mergeStmt->bindValue(8, time(), \PDO::PARAM_INT);
|
|
} else {
|
|
$mergeStmt->bindParam(':id', $sessionId, \PDO::PARAM_STR);
|
|
$mergeStmt->bindParam(':data', $data, \PDO::PARAM_LOB);
|
|
$mergeStmt->bindValue(':expiry', time() + $maxlifetime, \PDO::PARAM_INT);
|
|
$mergeStmt->bindValue(':time', time(), \PDO::PARAM_INT);
|
|
}
|
|
|
|
return $mergeStmt;
|
|
}
|
|
|
|
/**
|
|
* Return a PDO instance.
|
|
*
|
|
* @return \PDO
|
|
*/
|
|
protected function getConnection()
|
|
{
|
|
if (null === $this->pdo) {
|
|
$this->connect($this->dsn ?: ini_get('session.save_path'));
|
|
}
|
|
|
|
return $this->pdo;
|
|
}
|
|
}
|