DiscoveryActivator.java

/*******************************************************************************
 *  Copyright (c)2010 REMAIN B.V. The Netherlands. (http://www.remainsoftware.com).
 *  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:
 *     Wim Jongman - initial API and implementation   
 *     Ahmed Aadel - initial API and implementation     
 *******************************************************************************/
package org.eclipse.ecf.provider.zookeeper;

import java.util.Dictionary;
import java.util.HashSet;
import java.util.Properties;
import java.util.Set;

import org.eclipse.core.runtime.SafeRunner;
import org.eclipse.ecf.core.ContainerTypeDescription;
import org.eclipse.ecf.core.identity.Namespace;
import org.eclipse.ecf.core.util.ExtensionRegistryRunnable;
import org.eclipse.ecf.discovery.IDiscoveryAdvertiser;
import org.eclipse.ecf.discovery.IDiscoveryLocator;
import org.eclipse.ecf.provider.zookeeper.core.ZooDiscoveryContainer;
import org.eclipse.ecf.provider.zookeeper.core.ZooDiscoveryContainerInstantiator;
import org.eclipse.ecf.provider.zookeeper.core.ZooDiscoveryNamespace;
import org.eclipse.ecf.provider.zookeeper.core.internal.BundleStoppingListener;
import org.eclipse.ecf.provider.zookeeper.util.Logger;
import org.eclipse.ecf.provider.zookeeper.util.PrettyPrinter;
import org.osgi.framework.Bundle;
import org.osgi.framework.BundleActivator;
import org.osgi.framework.BundleContext;
import org.osgi.framework.ServiceFactory;
import org.osgi.framework.ServiceReference;
import org.osgi.framework.ServiceRegistration;
import org.osgi.service.log.LogService;
import org.osgi.util.tracker.ServiceTracker;

public class DiscoveryActivator implements BundleActivator {

	private static BundleContext context;
	private ServiceRegistration discoveryRegistration;
	private static Set<BundleStoppingListener> stopListeners = new HashSet<BundleStoppingListener>();
	private ServiceTracker confTracker, logServiceTracker;

	public void start(final BundleContext ctxt) {
		context = ctxt;
		
		SafeRunner.run(new ExtensionRegistryRunnable(ctxt) {
			protected void runWithoutRegistry() throws Exception {
				ctxt.registerService(Namespace.class,new ZooDiscoveryNamespace(), null);
				ctxt.registerService(ContainerTypeDescription.class,new ContainerTypeDescription(ZooDiscoveryContainerInstantiator.NAME,new ZooDiscoveryContainerInstantiator(),"Zookeeper Discovery Container"), null);
				ctxt.registerService(ContainerTypeDescription.class,new ContainerTypeDescription(ZooDiscoveryContainerInstantiator.NAME+".advertiser",new ZooDiscoveryContainerInstantiator(),"Zookeeper Discovery Advertiser Container"), null);
				ctxt.registerService(ContainerTypeDescription.class,new ContainerTypeDescription(ZooDiscoveryContainerInstantiator.NAME+".locator",new ZooDiscoveryContainerInstantiator(),"Zookeeper Discovery Locator Container"), null);				
			}
		});
		
		final Properties props = new Properties();
		props.put(IDiscoveryLocator.CONTAINER_NAME, ZooDiscoveryContainerInstantiator.NAME);
		props.put(IDiscoveryAdvertiser.CONTAINER_NAME, ZooDiscoveryContainerInstantiator.NAME);
		// register ourselves using a service factory
		discoveryRegistration = ctxt.registerService(
				new String[] { IDiscoveryLocator.class.getName(), IDiscoveryAdvertiser.class.getName() }, new ServiceFactory() {
					private volatile ZooDiscoveryContainer zdc;

					public Object getService(Bundle bundle, ServiceRegistration registration) {
						if (zdc == null) {
							zdc = ZooDiscoveryContainer.getSingleton();
							zdc.setDiscoveryProperties(props);
						}
						return zdc;
					}

					public void ungetService(Bundle bundle, ServiceRegistration registration, Object service) {

					}
				}, (Dictionary) props);

		// setup and open log service tracker
		logServiceTracker = new ServiceTracker(ctxt, org.osgi.service.log.LogService.class.getName(), null) {
			public Object addingService(ServiceReference reference) {
				Logger.bindLogService((LogService) context.getService(reference));
				return super.addingService(reference);
			}

			public void removedService(ServiceReference reference, Object service) {
				Logger.unbindLogService((LogService) service);
				super.removedService(reference, service);
			}
		};

		logServiceTracker.open(true);

		// Autostart by consuming our own service
		if (ZooDiscoveryContainer.autoStart()) {
			ctxt.getService(discoveryRegistration.getReference());
		}

	}

	public void stop(BundleContext c) throws Exception {
		dispose();
		Logger.log(LogService.LOG_INFO, PrettyPrinter.prompt(PrettyPrinter.DEACTIVATED, null), null);
	}

	private void dispose() {
		for (BundleStoppingListener l : stopListeners) {
			l.bundleStopping();
		}
		stopListeners.clear();
		ZooDiscoveryContainer.getSingleton().shutdown();
		if (this.discoveryRegistration != null) {
			this.discoveryRegistration.unregister();
		}
		if (this.confTracker != null) {
			this.confTracker.close();
		}
		// Initiates an orderly shutdown of all our cached threads
		ZooDiscoveryContainer.CACHED_THREAD_POOL.shutdown();

	}

	public static BundleContext getContext() {
		return context;
	}

	public static void registerBundleStoppingListner(BundleStoppingListener l) {
		stopListeners.add(l);
	}

}