QueueWorkerInterface.php

<?php

namespace Drupal\Core\Queue;

use Drupal\Component\Plugin\PluginInspectionInterface;

/**
 * Defines an interface for a QueueWorker plugin.
 *
 * @see \Drupal\Core\Queue\QueueWorkerBase
 * @see \Drupal\Core\Queue\QueueWorkerManager
 * @see \Drupal\Core\Annotation\QueueWorker
 * @see plugin_api
 *
 * @ingroup queue
 */
interface QueueWorkerInterface extends PluginInspectionInterface {
    
    /**
     * Works on a single queue item.
     *
     * @param mixed $data
     *   The data that was passed to
     *   \Drupal\Core\Queue\QueueInterface::createItem() when the item was queued.
     *
     * @throws \Drupal\Core\Queue\RequeueException
     *   Processing is not yet finished. This will allow another process to claim
     *   the item immediately.
     * @throws \Exception
     *   A QueueWorker plugin may throw an exception to indicate there was a
     *   problem. The cron process will log the exception, and leave the item in
     *   the queue to be processed again later.
     * @throws \Drupal\Core\Queue\SuspendQueueException
     *   More specifically, a SuspendQueueException should be thrown when a
     *   QueueWorker plugin is aware that the problem will affect all subsequent
     *   workers of its queue. For example, a callback that makes HTTP requests
     *   may find that the remote server is not responding. The cron process will
     *   behave as with a normal Exception, and in addition will not attempt to
     *   process further items from the current item's queue during the current
     *   cron run.
     * @throws \Drupal\Core\Queue\DelayedRequeueException
     *   To leave an item in the queue until its lock expires.
     *
     * @see \Drupal\Core\Cron::processQueues()
     */
    public function processItem($data);

}