Package com.epam.fixengine.storage.queue

Interface Queue<T extends Queueable>

All Known Implementing Classes:
InMemoryQueue, MMFPersistentInMemoryQueue, PersistentInMemoryQueue
public interface Queue<T extends Queueable>
Queue interface.

  • Method Summary

    Modifier and Type
    Method
    Description
    boolean
    add(T element)
    Add object to the queue.
    boolean
    addOutOfTurn(T element)
    Add object to the queue out of turn.
    void
    clear()
    Clears the queue.
    default void
    clearOutOfTurn(Consumer<T> elementConsumer)
    Removes the elements which were added by addOutOfTurn.
    void
    commit()
    Removes polled object from the queue.
    void
    initialize()
    Initializes queue.
    boolean
    isAllEmpty()
     
    boolean
    isEmpty()
    Checks if queue is currently empty.
    boolean
    isOutOfTurnOnlyMode()
    Out of turn messages only mode.
    void
    notifyAllApplication()
    Notify a new application message exists.
    void
    notifyAllSession()
    Notify a new session message exists.
    T
    poll()
    Poll object from the queue (doesn't remove it from queue yet!).
    void
    setOutOfTurnOnlyMode(boolean mode)
    Out of turn messages only mode.
    void
    shutdown()
    Gracefully shutdowns queue.
    int
    size()
    Returns current queue size.
    Queueable[]
    toArray()
    Return all objects in the queue as array.
    int
    totalSize()
    Returns current total queue size.

  • Method Details

    • initialize

      void initialize()
      Initializes queue. That includes restore of previously saved queue content for persistent queues.

    • add

      boolean add(T element)
      Add object to the queue.
      Parameters:
      element - the element
      Returns:
      true if element added successfully.

    • addOutOfTurn

      boolean addOutOfTurn(T element)
      Add object to the queue out of turn.
      Parameters:
      element - the element
      Returns:
      true if element added successfully.

    • setOutOfTurnOnlyMode

      void setOutOfTurnOnlyMode(boolean mode)
      Out of turn messages only mode.
      Parameters:
      mode - the mode

    • clearOutOfTurn

      default void clearOutOfTurn(Consumer<T> elementConsumer)
      Removes the elements which were added by addOutOfTurn.
      Parameters:
      elementConsumer - callback for each removed message. It is called after removing next message.

    • isAllEmpty

      boolean isAllEmpty()

    • poll

      T poll()
      Poll object from the queue (doesn't remove it from queue yet!).
      Returns:
      the head of this queue, or null if this queue is empty
      See Also:

    • commit

      void commit()
      Removes polled object from the queue. If nothing was polled - throws IllegalStateException
      See Also:

    • isEmpty

      boolean isEmpty()
      Checks if queue is currently empty.
      Returns:
      true if empty

    • size

      int size()
      Returns current queue size.
      Returns:
      queue size

    • totalSize

      int totalSize()
      Returns current total queue size. The total size of the usual queue and the OutOfTurn queue.
      Returns:
      queue size

    • clear

      void clear()
      Clears the queue.

    • shutdown

      void shutdown()
      Gracefully shutdowns queue.

    • isOutOfTurnOnlyMode

      boolean isOutOfTurnOnlyMode()
      Out of turn messages only mode.

    • notifyAllApplication

      void notifyAllApplication()
      Notify a new application message exists.

      The methods works only if turn "mode on" is off.

      See Also:

    • notifyAllSession

      void notifyAllSession()
      Notify a new session message exists.

    • toArray

      Queueable[] toArray()
      Return all objects in the queue as array. Method has no impact on poll / commit operations.
      Returns:
      array of Queueable