/** The metadata associated with the URL queue. */
    protected String metaData;

    /** The encoding of the URL queue. */
    protected String encoding;

    /** The parent URL of the current URL in the queue. */
    protected String parentUrl;

    /** The depth of the URL in the queue. */
    protected Integer depth;

    /** The last modified timestamp of the URL in the queue. */
    protected Long lastModified;

/**
 * A bounded {@linkplain BlockingQueue blocking queue} backed by an array. This queue orders
 * elements FIFO (first-in-first-out). The head of the queue is that element that has been
 * on the queue the longest time. The tail of the queue is that element that has been on
 * the queue the shortest time. New elements are inserted at the tail of the queue, and the queue
 * retrieval operations obtain elements at the head of the queue.

   * formally, removes an element {@code e} such that {@code o.equals(e)}, if this queue contains
   * one or more such elements. Returns {@code true} if and only if this queue contained the
   * specified element (or equivalently, if this queue changed as a result of the call).
   *
   * @param o element to be removed from this queue, if present

                }
            }
        }
        return OptionalEntity.empty();
    }

    /**
     * Processes the search log queue.
     *
     * @param queue The search log queue.
     */
    protected void processSearchLogQueue(final Queue<SearchLog> queue) {
        final FessConfig fessConfig = ComponentUtil.getFessConfig();
        final String value = fessConfig.getPurgeByBots();
        String[] botNames;

        sessionMap.clear();
    }

    /**
     * Returns the URL queue for the specified session ID.
     * Creates a new queue if one doesn't exist.
     * @param sessionId the session ID
     * @return the URL queue for the session
     */
    public synchronized Queue<UrlQueueImpl<Long>> getUrlQueueList(final String sessionId) {
        Queue<UrlQueueImpl<Long>> urlQueueList = urlQueueMap.get(sessionId);

    task.nextExecuteNanoTime = -1L
    val queue = task.queue!!
    queue.futureTasks.remove(task)
    readyQueues.remove(queue)
    queue.activeTask = task
    busyQueues.add(queue)
  }

  private fun afterRun(
    task: Task,
    delayNanos: Long,
    completedNormally: Boolean,
  ) {
    assertLockHeld()

    val queue = task.queue!!
    check(queue.activeTask === task)

  private final Executor executor;

  @GuardedBy("queue")
  private final Deque<Runnable> queue = new ArrayDeque<>();

  /** see {@link WorkerRunningState} */
  @LazyInit
  @GuardedBy("queue")
  private WorkerRunningState workerRunningState = IDLE;

  /**
   * This counter prevents an ABA issue where a thread may successfully schedule the worker, the
   * worker runs and exhausts the queue, another thread enqueues a task and fails to schedule the

        assertTrue(fesenClient.prepareSearch("fess_crawler.queue")
                .setQuery(QueryBuilders.termQuery("sessionId", "id1"))
                .execute()
                .actionGet()
                .getHits()
                .getTotalHits()
                .value() > 0);
        assertTrue(fesenClient.prepareSearch("fess_crawler.queue")
                .setQuery(QueryBuilders.termQuery("sessionId", "id2"))

 * This class provides methods for managing a queue of URLs to be crawled,
 * including adding, deleting, and retrieving URLs from the queue.
 * It uses a {@link MemoryDataHelper} to store the URL queue data in memory.
 *
 * <p>
 * The class is responsible for:
 * </p>
 * <ul>
 *   <li>Updating session IDs for URL queues.</li>
 *   <li>Adding new URLs to the queue.</li>

     */
    protected String charsetName = CoreLibConstants.UTF_8;

    /**
     * The queue of ciphers for encryption.
     */
    protected Queue<Cipher> encryptoQueue = new ConcurrentLinkedQueue<>();

    /**
     * The queue of ciphers for decryption.
     */
    protected Queue<Cipher> decryptoQueue = new ConcurrentLinkedQueue<>();

    /**
     * Encrypts the given data.
     *