class Batch

class Batch extends DatabaseQueue {

  /**
   * Overrides \Drupal\Core\Queue\DatabaseQueue::claimItem().
   *
   * Unlike \Drupal\Core\Queue\DatabaseQueue::claimItem(), this method provides
   * a default lease time of 0 (no expiration) instead of 30. This allows the
   * item to be claimed repeatedly until it is deleted.
   */
  public function claimItem($lease_time = 0) {
    try {
      $item = $this->connection
        ->queryRange('SELECT [data], [item_id] FROM {queue} q WHERE [name] = :name ORDER BY [item_id] ASC', 0, 1, [
        ':name' => $this->name,
      ])
        ->fetchObject();
      if ($item) {
        $item->data = unserialize($item->data);
        return $item;
      }
    } catch (\Exception $e) {
      $this
        ->catchException($e);
    }
    return FALSE;
  }

  /**
   * Retrieves all remaining items in the queue.
   *
   * This is specific to Batch API and is not part of the
   * \Drupal\Core\Queue\QueueInterface.
   *
   * @return array
   *   An array of queue items.
   */
  public function getAllItems() {
    $result = [];
    try {
      $items = $this->connection
        ->query('SELECT [data] FROM {queue} q WHERE [name] = :name ORDER BY [item_id] ASC', [
        ':name' => $this->name,
      ])
        ->fetchAll();
      foreach ($items as $item) {
        $result[] = unserialize($item->data);
      }
    } catch (\Exception $e) {
      $this
        ->catchException($e);
    }
    return $result;
  }

}