DiscoveryAgent.java

/**
 * Copyright (c) 2006 Ecliptical Software Inc. and others.
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License v1.0
 * which accompanies this distribution, and is available at
 * http://www.eclipse.org/legal/epl-v10.html
 * 
 * Contributors:
 *     Ecliptical Software Inc. - initial API and implementation
 */
package org.eclipse.ecf.pubsub.impl;

import java.io.IOException;
import java.util.ArrayList;
import java.util.Map;

import org.eclipse.core.runtime.PlatformObject;
import org.eclipse.ecf.core.events.IContainerConnectedEvent;
import org.eclipse.ecf.core.events.IContainerDisconnectedEvent;
import org.eclipse.ecf.core.identity.ID;
import org.eclipse.ecf.core.sharedobject.ISharedObject;
import org.eclipse.ecf.core.sharedobject.ISharedObjectConfig;
import org.eclipse.ecf.core.sharedobject.ISharedObjectContext;
import org.eclipse.ecf.core.sharedobject.ISharedObjectManager;
import org.eclipse.ecf.core.sharedobject.ReplicaSharedObjectDescription;
import org.eclipse.ecf.core.sharedobject.SharedObjectInitException;
import org.eclipse.ecf.core.sharedobject.events.ISharedObjectActivatedEvent;
import org.eclipse.ecf.core.sharedobject.events.ISharedObjectDeactivatedEvent;
import org.eclipse.ecf.core.sharedobject.events.ISharedObjectMessageEvent;
import org.eclipse.ecf.core.util.Event;
import org.eclipse.ecf.example.pubsub.SerializationUtil;
import org.eclipse.ecf.pubsub.IPublishedService;
import org.eclipse.ecf.pubsub.PublishedServiceDescriptor;

public class DiscoveryAgent extends PlatformObject implements ISharedObject {
	
	protected static final Object DIRECTORY_KEY = new Integer(0);

	protected ISharedObjectConfig config;
	
	protected PublishedServiceDirectory directory;

	public void init(ISharedObjectConfig config) throws SharedObjectInitException {
		if (config.getContext().getLocalContainerID().equals(config.getHomeContainerID())) {
			directory = (PublishedServiceDirectory) config.getProperties().get(DIRECTORY_KEY);
			if (directory == null)
				throw new SharedObjectInitException("Directory is required.");
		}
		
		this.config = config;
	}

	public void handleEvent(Event event) {
		if (event instanceof ISharedObjectActivatedEvent) {
			ISharedObjectActivatedEvent e = (ISharedObjectActivatedEvent) event;
			if (e.getActivatedID().equals(config.getSharedObjectID()))
				activated();
			else
				activated(e.getActivatedID());
		} else if (event instanceof ISharedObjectDeactivatedEvent) {
			ISharedObjectDeactivatedEvent e = (ISharedObjectDeactivatedEvent) event;
			if (e.getDeactivatedID().equals(config.getSharedObjectID()))
				deactivated();
			else
				deactivated(e.getDeactivatedID());
		} else if (event instanceof IContainerConnectedEvent) {
			IContainerConnectedEvent e = (IContainerConnectedEvent) event;
			if (e.getTargetID().equals(e.getLocalContainerID()))
				connected();
			else
				connected(e.getTargetID());
		} else if (event instanceof IContainerDisconnectedEvent) {
			IContainerDisconnectedEvent e = (IContainerDisconnectedEvent) event;
			if (e.getTargetID().equals(e.getLocalContainerID()))
				disconnected();
			else
				disconnected(e.getTargetID());
		} else if (event instanceof ISharedObjectMessageEvent)
			received((ISharedObjectMessageEvent) event);
	}
	
	protected boolean isConnected() {
		return config.getContext().getConnectedID() != null;
	}
	
	protected boolean isPrimary() {
		return config.getContext().getLocalContainerID().equals(config.getHomeContainerID());
	}
	
	protected void activated(ID sharedObjectID) {
		if (isPrimary())
			return;
		
		ISharedObjectContext ctx = config.getContext();
		Object object = ctx.getSharedObjectManager().getSharedObject(sharedObjectID);
		if (object instanceof IPublishedService) {
			IPublishedService svc = (IPublishedService) object;
			Map props = svc.getProperties();
			PublishedServiceDescriptor desc = new PublishedServiceDescriptor(ctx.getLocalContainerID(), sharedObjectID, props);
			try {
				ctx.sendMessage(config.getHomeContainerID(), SerializationUtil.serialize(new DiscoveryMessage(DiscoveryMessage.ADDED, desc)));
			} catch (IOException e) {
				// TODO Auto-generated catch block
				e.printStackTrace();
			}
		}
	}
	
	protected void activated() {
		if (isConnected())
			connected();
	}
	
	protected void deactivated(ID sharedObjectID) {
		if (isPrimary())
			return;

		ISharedObjectContext ctx = config.getContext();
		Object object = ctx.getSharedObjectManager().getSharedObject(sharedObjectID);
		if (object instanceof IPublishedService) {
			IPublishedService svc = (IPublishedService) object;
			Map props = svc.getProperties();
			PublishedServiceDescriptor desc = new PublishedServiceDescriptor(ctx.getLocalContainerID(), sharedObjectID, props);
			try {
				ctx.sendMessage(config.getHomeContainerID(), SerializationUtil.serialize(new DiscoveryMessage(DiscoveryMessage.REMOVED, desc)));
			} catch (IOException e) {
				// TODO Auto-generated catch block
				e.printStackTrace();
			}
		}
	}
	
	protected void deactivated() {
		if (isPrimary() && isConnected())
			try {
				config.getContext().sendDispose(null);
			} catch (IOException e) {
				// TODO Auto-generated catch block
				e.printStackTrace();
			}
	}
	
	protected void connected(ID containerID) {
		if (isPrimary())
			try {
				config.getContext().sendCreate(containerID, new ReplicaSharedObjectDescription(getClass(), config.getSharedObjectID()));
			} catch (IOException e) {
				// TODO Auto-generated catch block
				e.printStackTrace();
			}
	}
	
	protected void connected() {
		if (isPrimary()) {
			try {
				config.getContext().sendCreate(null, new ReplicaSharedObjectDescription(getClass(), config.getSharedObjectID()));
			} catch (IOException e) {
				// TODO Auto-generated catch block
				e.printStackTrace();
			}
		} else {
			ArrayList published = new ArrayList();
			ISharedObjectContext ctx = config.getContext();
			ISharedObjectManager mgr = ctx.getSharedObjectManager();
			ID[] ids = mgr.getSharedObjectIDs();
			ID containerID = ctx.getLocalContainerID();
			for (int i = 0; i < ids.length; ++i) {
				Object object = mgr.getSharedObject(ids[i]);
				if (object instanceof IPublishedService) {
					IPublishedService svc = (IPublishedService) object;
					Map props = svc.getProperties();
					published.add(new PublishedServiceDescriptor(containerID, ids[i], props));
				}
			}
			
			if (published.isEmpty())
				return;
			
			PublishedServiceDescriptor[] descriptors = new PublishedServiceDescriptor[published.size()];
			published.toArray(descriptors);
			try {
				ctx.sendMessage(config.getHomeContainerID(), SerializationUtil.serialize(new DiscoveryMessage(DiscoveryMessage.ADDED, descriptors)));
			} catch (IOException e) {
				// TODO Auto-generated catch block
				e.printStackTrace();
			}
		}
	}
	
	protected void disconnected(ID containerID) {
		if (containerID.equals(config.getHomeContainerID()))
			config.getContext().getSharedObjectManager().removeSharedObject(config.getSharedObjectID());
	}
	
	protected void disconnected() {
		config.getContext().getSharedObjectManager().removeSharedObject(config.getSharedObjectID());
	}
	
	protected void received(ISharedObjectMessageEvent event) {
		Object data = event.getData();
		if (!(data instanceof byte[]))
			return;
		
		try {
			data = SerializationUtil.deserialize((byte[]) data);
		} catch (IOException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
			return;
		} catch (ClassNotFoundException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
			return;
		}
		
		if (!(data instanceof DiscoveryMessage))
			return;
		
		directory.handleDiscovery(event.getRemoteContainerID(), (DiscoveryMessage) data);
	}

	public void handleEvents(Event[] events) {
		for (int i = 0; i < events.length; ++i)
			handleEvent(events[i]);
	}
	
	public void dispose(ID containerID) {
		config = null;
		directory = null;
	}
}