RemoteServiceContainer.java

/*******************************************************************************
* Copyright (c) 2009 EclipseSource 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:
*   EclipseSource - initial API and implementation
******************************************************************************/
package org.eclipse.ecf.remoteservice;

import org.eclipse.core.runtime.Assert;
import org.eclipse.ecf.core.ContainerConnectException;
import org.eclipse.ecf.core.IContainer;
import org.eclipse.ecf.core.identity.ID;
import org.eclipse.ecf.core.identity.IDFactory;
import org.osgi.framework.InvalidSyntaxException;

/**
 * @since 3.0
 */
public class RemoteServiceContainer implements IRemoteServiceContainer {

	private final IContainer container;
	private final IRemoteServiceContainerAdapter containerAdapter;

	public RemoteServiceContainer(IContainer container, IRemoteServiceContainerAdapter containerAdapter) {
		Assert.isNotNull(container);
		Assert.isNotNull(containerAdapter);
		this.container = container;
		this.containerAdapter = containerAdapter;
	}

	/**
	 * @since 3.2
	 * @param container container
	 */
	@SuppressWarnings("cast")
	public RemoteServiceContainer(IContainer container) {
		this(container, (IRemoteServiceContainerAdapter) container.getAdapter(IRemoteServiceContainerAdapter.class));
	}

	public IContainer getContainer() {
		return container;
	}

	public IRemoteServiceContainerAdapter getContainerAdapter() {
		return containerAdapter;
	}

	public IRemoteService getRemoteService(String targetLocation, String serviceInterfaceClass, String filter) throws ContainerConnectException, InvalidSyntaxException {
		ID targetID = null;
		if (targetLocation != null) {
			targetID = IDFactory.getDefault().createID(getContainer().getConnectNamespace(), targetLocation);
		}
		IRemoteServiceReference serviceReference = getServiceReference(targetID, serviceInterfaceClass, filter);
		if (serviceReference == null)
			return null;
		return getContainerAdapter().getRemoteService(serviceReference);
	}

	protected IRemoteServiceReference getServiceReference(ID targetId, String serviceInterfaceClass, String filter) throws ContainerConnectException, InvalidSyntaxException {
		IRemoteServiceReference[] references = getContainerAdapter().getRemoteServiceReferences(targetId, serviceInterfaceClass, filter);
		if (references == null || references.length == 0)
			return null;
		return selectReference(references);
	}

	protected IRemoteServiceReference selectReference(IRemoteServiceReference[] references) {
		int length = (references == null) ? 0 : references.length;
		if (length == 0) { /* if no service is being tracked */
			return null;
		}
		int index = 0;
		if (length > 1) { /* if more than one service, select highest ranking */
			int rankings[] = new int[length];
			int count = 0;
			int maxRanking = Integer.MIN_VALUE;
			for (int i = 0; i < length; i++) {
				Object property = references[i].getProperty(org.eclipse.ecf.remoteservice.Constants.SERVICE_RANKING);
				int ranking = (property instanceof Integer) ? ((Integer) property).intValue() : 0;
				rankings[i] = ranking;
				if (ranking > maxRanking) {
					index = i;
					maxRanking = ranking;
					count = 1;
				} else {
					if (ranking == maxRanking) {
						count++;
					}
				}
			}
			if (count > 1) { /* if still more than one service, select lowest id */
				long minId = Long.MAX_VALUE;
				for (int i = 0; i < length; i++) {
					if (rankings[i] == maxRanking) {
						long id = ((Long) (references[i].getProperty(org.eclipse.ecf.remoteservice.Constants.SERVICE_ID))).longValue();
						if (id < minId) {
							index = i;
							minId = id;
						}
					}
				}
			}
		}
		return references[index];
	}

	public IRemoteService getRemoteService(String targetLocation, String serviceInterfaceClass) throws ContainerConnectException {
		try {
			return getRemoteService(targetLocation, serviceInterfaceClass, null);
		} catch (InvalidSyntaxException e) {
			// Cannot happen
			return null;
		}
	}

	public IRemoteService getRemoteService(String serviceInterfaceClass) {
		try {
			return getRemoteService(null, serviceInterfaceClass);
		} catch (ContainerConnectException e) {
			// if targetLocation is null, cannot happen
			return null;
		}
	}

	public String toString() {
		StringBuffer buffer = new StringBuffer();
		buffer.append("RemoteServiceContainer [containerID="); //$NON-NLS-1$
		buffer.append(container.getID());
		buffer.append(", container="); //$NON-NLS-1$
		buffer.append(container);
		buffer.append(", containerAdapter="); //$NON-NLS-1$
		buffer.append(containerAdapter);
		buffer.append("]"); //$NON-NLS-1$
		return buffer.toString();
	}

}