interface SessionStorageInterface

Session.php in drupal/core/vendor/symfony/http-foundation/Symfony/Component/HttpFoundation/Session/Session.php

interface SessionStorageInterface {

  /**
   * Starts the session.
   *
   * @throws \RuntimeException If something goes wrong starting the session.
   *
   * @return boolean True if started.
   *
   * @api
   */
  public function start();

  /**
   * Checks if the session is started.
   *
   * @return boolean True if started, false otherwise.
   */
  public function isStarted();

  /**
   * Returns the session ID
   *
   * @return string The session ID or empty.
   *
   * @api
   */
  public function getId();

  /**
   * Sets the session ID
   *
   * @param string $id
   *
   * @api
   */
  public function setId($id);

  /**
   * Returns the session name
   *
   * @return mixed The session name.
   *
   * @api
   */
  public function getName();

  /**
   * Sets the session name
   *
   * @param string $name
   *
   * @api
   */
  public function setName($name);

  /**
   * Regenerates id that represents this storage.
   *
   * This method must invoke session_regenerate_id($destroy) unless
   * this interface is used for a storage object designed for unit
   * or functional testing where a real PHP session would interfere
   * with testing.
   *
   * Note regenerate+destroy should not clear the session data in memory
   * only delete the session data from persistent storage.
   *
   * @param Boolean $destroy  Destroy session when regenerating?
   * @param integer $lifetime Sets the cookie lifetime for the session cookie. A null value
   *                          will leave the system settings unchanged, 0 sets the cookie
   *                          to expire with browser session. Time is in seconds, and is
   *                          not a Unix timestamp.
   *
   * @return Boolean True if session regenerated, false if error
   *
   * @throws \RuntimeException If an error occurs while regenerating this storage
   *
   * @api
   */
  public function regenerate($destroy = false, $lifetime = null);

  /**
   * Force the session to be saved and closed.
   *
   * This method must invoke session_write_close() unless this interface is
   * used for a storage object design for unit or functional testing where
   * a real PHP session would interfere with testing, in which case it
   * it should actually persist the session data if required.
   *
   * @throws \RuntimeException If the session is saved without being started, or if the session
   *                           is already closed.
   */
  public function save();

  /**
   * Clear all session data in memory.
   */
  public function clear();

  /**
   * Gets a SessionBagInterface by name.
   *
   * @param string $name
   *
   * @return SessionBagInterface
   *
   * @throws \InvalidArgumentException If the bag does not exist
   */
  public function getBag($name);

  /**
   * Registers a SessionBagInterface for use.
   *
   * @param SessionBagInterface $bag
   */
  public function registerBag(SessionBagInterface $bag);

  /**
   * @return MetadataBag
   */
  public function getMetadataBag();

}