WorldEventFuture implementation

Signed-off-by: Rogiel <rogiel@rogiel.com>

pom.xml

@@ -120,6 +120,13 @@
 			<type>jar</type>
 			<scope>runtime</scope>
 		</dependency>
+		<dependency>
+			<groupId>com.google.guava</groupId>
+			<artifactId>guava</artifactId>
+			<version>r09</version>
+			<type>jar</type>
+			<scope>runtime</scope>
+		</dependency>
 	</dependencies>
 
 	<issueManagement>

src/main/java/com/l2jserver/service/game/world/CachedWorldIDService.java

@@ -102,6 +102,11 @@ public class CachedWorldIDService extends AbstractService implements
 		loaded = true;
 	}
 
+	@Override
+	public void unload() {
+		cache.removeAll();
+	}
+
 	/**
 	 * Load the pre-existing ids
 	 * 

src/main/java/com/l2jserver/service/game/world/WorldIDService.java

@@ -35,6 +35,11 @@ public interface WorldIDService extends Service {
 	 */
 	void load();
 
+	/**
+	 * Unload all loaded {@link ObjectID}
+	 */
+	void unload();
+
 	/**
 	 * Tries to resolve an ID based on its raw value
 	 * 

src/main/java/com/l2jserver/service/game/world/WorldServiceImpl.java

@@ -82,6 +82,7 @@ public class WorldServiceImpl extends AbstractService implements WorldService {
 	protected void doStart() throws ServiceStartException {
 		objects.clear();
 		idService.load();
+		dispatcher.start();
 	}
 
 	@Override
@@ -172,5 +173,7 @@ public class WorldServiceImpl extends AbstractService implements WorldService {
 	@Override
 	protected void doStop() throws ServiceStopException {
 		objects.clear();
+		idService.unload();
+		dispatcher.stop();
 	}
 }

src/main/java/com/l2jserver/service/game/world/event/WorldEventDispatcher.java

@@ -31,10 +31,14 @@ public interface WorldEventDispatcher {
 	 * need to invoke listeners immediately. Dispatching <b>can</b> occur
 	 * concurrently.
 	 * 
+	 * @param <E>
+	 *            the event type
 	 * @param event
 	 *            the event
+	 * @return the future. The future can be used to be notified once the event
+	 *         has been dispatched to all listeners.
 	 */
-	void dispatch(WorldEvent event);
+	<E extends WorldEvent> WorldEventFuture<E> dispatch(E event);
 
 	/**
 	 * Adds a new global <tt>listener</tt>

src/main/java/com/l2jserver/service/game/world/event/WorldEventDispatcherImpl.java

@@ -21,10 +21,14 @@ import java.util.Queue;
 import java.util.Set;
 import java.util.Timer;
 import java.util.TimerTask;
+import java.util.concurrent.ExecutionException;
+import java.util.concurrent.TimeUnit;
+import java.util.concurrent.TimeoutException;
 
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
+import com.google.common.util.concurrent.AbstractFuture;
 import com.l2jserver.model.id.ObjectID;
 import com.l2jserver.model.world.WorldObject;
 import com.l2jserver.util.factory.CollectionFactory;
@@ -35,28 +39,51 @@ import com.l2jserver.util.factory.CollectionFactory;
  * @author <a href="http://www.rogiel.com">Rogiel</a>
  */
 public class WorldEventDispatcherImpl implements WorldEventDispatcher {
+	/**
+	 * The logger
+	 */
 	private static final Logger log = LoggerFactory
 			.getLogger(WorldEventDispatcherImpl.class);
 
-	private final Timer timer = new Timer();
+	/**
+	 * The execution thread
+	 */
+	private Timer timer;
 
+	/**
+	 * The list of all global listeners
+	 */
 	private Set<WorldListener> globalListeners = CollectionFactory.newSet();
+	/**
+	 * The {@link Map} containing all listeners for every object
+	 */
 	private Map<ObjectID<?>, Set<WorldListener>> listeners = CollectionFactory
 			.newMap();
-	// private Queue<ListenerIDPair> listeners = CollectionFactory
-	// .newConcurrentQueue(ListenerIDPair.class);
-	private Queue<WorldEvent> events = CollectionFactory.newConcurrentQueue();
+	/**
+	 * The events pending dispatch
+	 */
+	private Queue<EventContainer> events = CollectionFactory
+			.newConcurrentQueue();
 
-	public WorldEventDispatcherImpl() {
+	public void start() {
+		timer = new Timer();
 		timer.scheduleAtFixedRate(new TimerTask() {
 			@Override
 			public void run() {
-				final WorldEvent event = events.poll();
+				final EventContainer event = events.poll();
 				if (event == null)
 					return;
 				try {
-					doDispatch(event);
+					// set state
+					event.future.running = true;
+					event.future.complete = false;
+
+					// dispatch
+					if (doDispatch(event))
+						// the set will update state
+						event.future.set(event.event);
 				} catch (Throwable t) {
+					event.future.setException(t);
 					log.warn("Exception in WorldEventDispatcher thread", t);
 				}
 			}
@@ -64,21 +91,32 @@ public class WorldEventDispatcherImpl implements WorldEventDispatcher {
 	}
 
 	@Override
-	public void dispatch(WorldEvent event) {
+	public <E extends WorldEvent> WorldEventFuture<E> dispatch(E event) {
 		log.debug("Queing dispatch for event {}", event);
-		events.add(event);
+		final WorldEventFutureImpl<E> future = new WorldEventFutureImpl<E>();
+		events.add(new EventContainer(event, future));
+		return future;
 	}
 
-	public void doDispatch(WorldEvent event) {
+	/**
+	 * Do the dispatching
+	 * 
+	 * @param event
+	 *            the event
+	 * @return true if dispatch was not canceled
+	 */
+	public boolean doDispatch(EventContainer event) {
 		log.debug("Dispatching event {}", event);
-		final ObjectID<?>[] objects = event.getDispatchableObjects();
+		final ObjectID<?>[] objects = event.event.getDispatchableObjects();
 		for (ObjectID<?> obj : objects) {
 			if (obj == null)
 				continue;
 			final Set<WorldListener> listeners = getListeners(obj);
 			for (final WorldListener listener : listeners) {
+				if (event.future.isCancelled())
+					return false;
 				try {
-					if (!listener.dispatch(event))
+					if (!listener.dispatch(event.event))
 						// remove listener if return value is false
 						listeners.remove(listener);
 				} catch (ClassCastException e) {
@@ -89,6 +127,7 @@ public class WorldEventDispatcherImpl implements WorldEventDispatcher {
 				}
 			}
 		}
+		return true;
 	}
 
 	@Override
@@ -134,6 +173,14 @@ public class WorldEventDispatcherImpl implements WorldEventDispatcher {
 		listeners.remove(id);
 	}
 
+	/**
+	 * Get the {@link Set} of listeners for an given object. Creates a new one
+	 * if does not exists.
+	 * 
+	 * @param id
+	 *            the object id
+	 * @return the {@link Set}. Never null.
+	 */
 	private Set<WorldListener> getListeners(ObjectID<?> id) {
 		Set<WorldListener> set = listeners.get(id);
 		if (set == null) {
@@ -142,4 +189,117 @@ public class WorldEventDispatcherImpl implements WorldEventDispatcher {
 		}
 		return set;
 	}
+	
+	public void stop() {
+		timer.cancel();
+		timer = null;
+	}
+
+	/**
+	 * {@link WorldEventFuture} implementation
+	 * 
+	 * @param <E>
+	 *            the event type
+	 * @author <a href="http://www.rogiel.com">Rogiel</a>
+	 */
+	private static class WorldEventFutureImpl<E extends WorldEvent> extends
+			AbstractFuture<E> implements WorldEventFuture<E> {
+		private boolean running = false;
+		private boolean complete = false;
+
+		@Override
+		@SuppressWarnings("unchecked")
+		protected boolean set(WorldEvent value) {
+			running = false;
+			complete = true;
+			return super.set((E) value);
+		}
+
+		@Override
+		protected boolean setException(Throwable throwable) {
+			return super.setException(throwable);
+		}
+
+		@Override
+		public boolean cancel(boolean mayInterruptIfRunning) {
+			if (!mayInterruptIfRunning && running)
+				return false;
+			if (complete)
+				return false;
+			return cancel();
+		}
+
+		@Override
+		public void await() throws InterruptedException {
+			try {
+				super.get();
+			} catch (ExecutionException e) {
+			}
+		}
+
+		@Override
+		public void await(long timeout, TimeUnit unit)
+				throws InterruptedException, TimeoutException {
+			try {
+				super.get(timeout, unit);
+			} catch (ExecutionException e) {
+			}
+		}
+
+		@Override
+		public boolean awaitUninterruptibly() {
+			try {
+				super.get();
+				return true;
+			} catch (InterruptedException e) {
+				return false;
+			} catch (ExecutionException e) {
+				return false;
+			}
+		}
+
+		@Override
+		public boolean awaitUninterruptibly(long timeout, TimeUnit unit) {
+			try {
+				super.get(timeout, unit);
+				return true;
+			} catch (InterruptedException e) {
+				return false;
+			} catch (ExecutionException e) {
+				return false;
+			} catch (TimeoutException e) {
+				return false;
+			}
+		}
+	}
+
+	/**
+	 * Simple container that contains an event and a future
+	 * 
+	 * @author <a href="http://www.rogiel.com">Rogiel</a>
+	 */
+	private static class EventContainer {
+		/**
+		 * The event
+		 */
+		private final WorldEvent event;
+		/**
+		 * The future
+		 */
+		private final WorldEventFutureImpl<? extends WorldEvent> future;
+
+		/**
+		 * Creates a new instance
+		 * 
+		 * @param event
+		 *            the event
+		 * @param future
+		 *            the future
+		 */
+		public EventContainer(WorldEvent event,
+				WorldEventFutureImpl<? extends WorldEvent> future) {
+			this.event = event;
+			this.future = future;
+		}
+	}
 }

src/main/java/com/l2jserver/service/game/world/event/WorldEventFuture.java

@@ -0,0 +1,74 @@
+/*
+ * This file is part of l2jserver <l2jserver.com>.
+ *
+ * l2jserver is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * l2jserver is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with l2jserver.  If not, see <http://www.gnu.org/licenses/>.
+ */
+package com.l2jserver.service.game.world.event;
+
+import java.util.concurrent.Future;
+import java.util.concurrent.TimeUnit;
+import java.util.concurrent.TimeoutException;
+
+/**
+ * This is an {@link Future} for {@link WorldEvent}. This {@link Future} can be
+ * used to receive notifications once an event has been dispatched to all
+ * listeners.
+ * 
+ * @author <a href="http://www.rogiel.com">Rogiel</a>
+ */
+public interface WorldEventFuture<E extends WorldEvent> extends Future<E> {
+	/**
+	 * Waits until the event is dispatched to all listeners
+	 * 
+	 * @throws InterruptedException
+	 *             if the thread has been interrupted while waiting
+	 */
+	void await() throws InterruptedException;
+
+	/**
+	 * Waits until the event is dispatched to all listeners
+	 * 
+	 * @param timeout
+	 *            the timeout
+	 * @param unit
+	 *            the timeout unit
+	 * 
+	 * @throws InterruptedException
+	 *             if the thread has been interrupted while waiting
+	 * @throws TimeoutException
+	 *             if timeout was exceeded
+	 */
+	void await(long timeout, TimeUnit unit) throws InterruptedException,
+			TimeoutException;
+
+	/**
+	 * Waits until the event is dispatched to all listeners
+	 * 
+	 * @return true if execution ended with no error, false otherwise
+	 */
+	boolean awaitUninterruptibly();
+
+	/**
+	 * Waits until the event is dispatched to all listeners
+	 * 
+	 * @param timeout
+	 *            the timeout
+	 * @param unit
+	 *            the timeout unit
+	 * 
+	 * @return true if execution ended with no error, false otherwise. Please
+	 *         note that false will be returned if the timeout has expired too!
+	 */
+	boolean awaitUninterruptibly(long timeout, TimeUnit unit);
+}