<?php

/*

 * This file is part of SwiftMailer.

 * (c) 2009 Fabien Potencier <fabien.potencier@gmail.com>

 *

 * For the full copyright and license information, please view the LICENSE

 * file that was distributed with this source code.

 */

/**

 * Interface for spools.

 * @package Swift

 * @author  Fabien Potencier

 */

interface Swift_Spool

{

  /**

   * Starts this Spool mechanism.

   */

  public function start();

  /**

   * Stops this Spool mechanism.

   */

  public function stop();

  /**

   * Tests if this Spool mechanism has started.

   *

   * @return boolean

   */

  public function isStarted();

  /**

   * Queues a message.

   * @param Swift_Mime_Message $message The message to store

   */

  public function queueMessage(Swift_Mime_Message $message);

  /**

   * Sends messages using the given transport instance.

   *

   * @param Swift_Transport $transport         A transport instance

   * @param string[]        &$failedRecipients An array of failures by-reference

   *

   * @return int The number of sent emails

   */

  public function flushQueue(Swift_Transport $transport, &$failedRecipients = null);

}