Module it.rebirthproject.ufoeb

Package it.rebirthproject.ufoeb.architecture.state

Class BusMemoryStateManager

java.lang.Object

it.rebirthproject.ufoeb.architecture.state.BusMemoryStateManager

All Implemented Interfaces:

Runnable

public class BusMemoryStateManager
extends Object
implements Runnable

The bus memory state manager which stores and manages events and listeners

Field Summary

Fields

Modifier and Type	Field	Description
private final BlockingQueue<Message>	commandQueryMessageQueue	The message queue is used by the BusMemoryStateManager to receive internal system messages.
private final CountDownLatch	countDownLatch	A CountDownLatch used during the shutdown phase to notify when the BusMemoryStateManager is shutting down.
private final ListenerMethodFinder	listenerMethodFinder	The ListenerMethodFinder is a service used to retrieve registered listeners methods annotated with Listen and to store them inside the MemoryState
private static final org.slf4j.Logger	logger	The logger used by this class
private final MemoryState	memoryState	The MemoryState of the EventBus
private final boolean	throwNoRegistrationsWarning	A boolean flag used to determine if a throwNoRegistrationsWarning should be raised or not.
private final ExecutorService	workersPoolExecutor	This is the thread pool cache that handles thread parallelism to obtain bus scalability.

Constructor Summary

Constructors

Constructor	Description
BusMemoryStateManager(BlockingQueue<Message> commandQueryMessageQueue, ExecutorService workersPoolExecutor, CountDownLatch countDownLatch, MemoryState memoryState, ListenerMethodFinder listenerMethodFinder, boolean throwNoRegistrationsWarning)	The constructor used to build the BusMemoryStateManager

Method Summary

Modifier and Type	Method	Description
private void	manageEventToPost(Object eventObjectToPost)	Private method used to handle a message to post to EventExecutors workers.
private void	postEvent(Object eventObjectToPost, Class<?> eventClass)	Private method used to send an event to EventExecutors workers
void	run()	This method is called when the BusMemoryStateManager (which implements the Runnable java interface) starts his work after being executed in a separated thread.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Details

logger

private static final org.slf4j.Logger logger

The logger used by this class

commandQueryMessageQueue

private final BlockingQueue<Message> commandQueryMessageQueue

The message queue is used by the BusMemoryStateManager to receive internal system messages.

example: (REGISTER_MESSAGE, UNREGISTER_MESSAGE, SHUTDOWN_STATE_MANAGER, etc... )

Once one of those messages is received, it will be handled accordingly.

workersPoolExecutor

private final ExecutorService workersPoolExecutor

This is the thread pool cache that handles thread parallelism to obtain bus scalability.

countDownLatch

private final CountDownLatch countDownLatch

A CountDownLatch used during the shutdown phase to notify when the BusMemoryStateManager is shutting down.

memoryState

private final MemoryState memoryState

The MemoryState of the EventBus

listenerMethodFinder

private final ListenerMethodFinder listenerMethodFinder

The ListenerMethodFinder is a service used to retrieve registered listeners methods annotated with Listen and to store them inside the MemoryState

throwNoRegistrationsWarning

private final boolean throwNoRegistrationsWarning

A boolean flag used to determine if a throwNoRegistrationsWarning should be raised or not. If the flag is false no warning be will be thrown when an event is posted and no listeners are registered to listen to that precise event.

Constructor Details

BusMemoryStateManager

public BusMemoryStateManager(BlockingQueue<Message> commandQueryMessageQueue,
 ExecutorService workersPoolExecutor,
 CountDownLatch countDownLatch,
 MemoryState memoryState,
 ListenerMethodFinder listenerMethodFinder,
 boolean throwNoRegistrationsWarning)

The constructor used to build the BusMemoryStateManager

Parameters:

commandQueryMessageQueue - The message queue is used by the BusMemoryStateManager to receive internal system messages.

example: (REGISTER_MESSAGE, UNREGISTER_MESSAGE, SHUTDOWN_STATE_MANAGER, etc... )

Once one of those messages is received, it will be handled accordingly.

workersPoolExecutor - This is the thread pool cache that handles thread parallelism to obtain bus scalability.

countDownLatch - A countDownLatch used during the shutdown phase to notify when the BusMemoryStateManager is shutting down.

memoryState - The MemoryState of the EventBus

listenerMethodFinder - The ListenerMethodFinder is a service used to retrieve registered listeners methods annotated with Listen and to store them inside the MemoryState

throwNoRegistrationsWarning - A boolean flag used to determine if a throwNoRegistrationsWarning should be raised or not. If the flag is false no warning be will be thrown when an event is posted and no listeners are registered to listen to that precise event.

Method Details

run

public void run()

This method is called when the BusMemoryStateManager (which implements the Runnable java interface) starts his work after being executed in a separated thread.

Specified by:

run in interface Runnable

manageEventToPost

private void manageEventToPost(Object eventObjectToPost)
                        throws InterruptedException

Private method used to handle a message to post to EventExecutors workers. This method will save data into memoryState if needed and then call the postEvent(Object, Class) method to notify an event to EventExecutors

Parameters:

eventObjectToPost - The event to post EventExecutors

Throws:

InterruptedException - If there is an exception trying to send an event to workers.

postEvent

private void postEvent(Object eventObjectToPost,
 Class<?> eventClass)
                throws InterruptedException

Private method used to send an event to EventExecutors workers

Parameters:

eventObjectToPost - The event to post to EventExecutors

eventClass - The event class

Throws:

InterruptedException - If there is an exception trying to send an event to workers.