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 and 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 Detail

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()

commit

void commit()

Removes polled object from the queue. If nothing was polled - throws IllegalStateException

See Also:

IllegalStateException

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:

setOutOfTurnOnlyMode(boolean)

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