RemoteServiceRegistration.java

/* Copyright (c) 2006-2009 Jan S. Rellermeyer
 * Systems Group,
 * Institute for Pervasive Computing, ETH Zurich.
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 *    - Redistributions of source code must retain the above copyright notice,
 *      this list of conditions and the following disclaimer.
 *    - Redistributions in binary form must reproduce the above copyright
 *      notice, this list of conditions and the following disclaimer in the
 *      documentation and/or other materials provided with the distribution.
 *    - Neither the name of ETH Zurich nor the names of its contributors may be
 *      used to endorse or promote products derived from this software without
 *      specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGE.
 */
package ch.ethz.iks.r_osgi.impl;

import java.lang.reflect.Method;
import java.util.Dictionary;
import java.util.HashMap;
import java.util.Hashtable;

import org.objectweb.asm.Type;
import org.osgi.framework.Constants;
import org.osgi.framework.ServiceReference;
import org.osgi.service.log.LogService;

import ch.ethz.iks.r_osgi.RemoteOSGiService;
import ch.ethz.iks.r_osgi.messages.DeliverServiceMessage;

/**
 * Encapsulates a service registered for remote access.
 * 
 * @author Jan S. Rellermeyer
 */
final class RemoteServiceRegistration {

	/**
	 * the local service reference.
	 */
	private final ServiceReference reference;

	/**
	 * the service id.
	 */
	private final long serviceID;

	/**
	 * the interface names.
	 */
	private final String[] interfaceNames;

	/**
	 * the service object.
	 */
	private final Object serviceObject;

	/**
	 * an internal method table, pregenerated to speed up the reflective calls.
	 */
	private final HashMap methodTable = new HashMap(0);

	/**
	 * a prefactored deliver service message.
	 */
	private DeliverServiceMessage deliverServiceMessage;

	/**
	 * creates a new RemoteService object.
	 * 
	 * @param ref
	 *            the <code>ServiceReference</code> under which the service was
	 *            registered. Can be a surrogate.
	 * @param service
	 *            the <code>ServiceReference</code>
	 * @throws ClassNotFoundException
	 *             if one of the interface classes cannot be found.
	 * @throws ServiceLocationException
	 */
	RemoteServiceRegistration(final ServiceReference ref,
			final ServiceReference service) throws ClassNotFoundException {

		reference = service;
		serviceID = ((Long) service.getProperty(Constants.SERVICE_ID))
				.longValue();
		interfaceNames = (String[]) service.getProperty(Constants.OBJECTCLASS);

		// get the service object
		serviceObject = RemoteOSGiActivator.getActivator().getContext().getService(service);
		if (serviceObject == null) {
			throw new IllegalStateException("Service is not present."); //$NON-NLS-1$
		}

		// get the interface classes
		final ClassLoader bundleLoader = serviceObject.getClass()
				.getClassLoader();
		final String[] interfaceNames = (String[]) service
				.getProperty(Constants.OBJECTCLASS);
		final int interfaceCount = interfaceNames.length;
		final Class[] serviceInterfaces = new Class[interfaceCount];

		// build up the method table for each interface
		for (int i = 0; i < interfaceCount; i++) {
			serviceInterfaces[i] = bundleLoader.loadClass(interfaceNames[i]);
			final Method[] methods = serviceInterfaces[i].getMethods();
			for (int j = 0; j < methods.length; j++) {
				methodTable.put(methods[j].getName()
						+ Type.getMethodDescriptor(methods[j]), methods[j]);
			}
		}

		final Dictionary headers = service.getBundle().getHeaders();
		final CodeAnalyzer analyzer = new CodeAnalyzer(bundleLoader,
				(String) headers.get(Constants.IMPORT_PACKAGE),
				(String) headers.get(Constants.EXPORT_PACKAGE));
		try {
			deliverServiceMessage = analyzer.analyze(interfaceNames,
					(String) ref.getProperty(RemoteOSGiService.SMART_PROXY),
					(String[]) ref.getProperty(RemoteOSGiService.INJECTIONS),
					(String) ref.getProperty(RemoteOSGiService.PRESENTATION));
			deliverServiceMessage.setServiceID(((Long) ref
					.getProperty(Constants.SERVICE_ID)).toString());
		} catch (final Exception e) {
			if (RemoteOSGiServiceImpl.log != null) {
				RemoteOSGiServiceImpl.log.log(LogService.LOG_ERROR,
						"Error during remote service registration", e); //$NON-NLS-1$
			}
		}
	}

	/**
	 * get the service id.
	 * 
	 * @return the service id.
	 * @since 0.5
	 */
	long getServiceID() {
		return serviceID;
	}

	ServiceReference getReference() {
		return reference;
	}

	/**
	 * get the service properties.
	 * 
	 * @return the properties.
	 */
	Dictionary getProperties() {
		final String[] keys = reference.getPropertyKeys();
		final Dictionary props = new Hashtable(keys.length);
		for (int i = 0; i < keys.length; i++) {
			props.put(keys[i], reference.getProperty(keys[i]));
		}
		return props;
	}

	/**
	 * get the service interfaces.
	 * 
	 * @return the class names of the service interfaces.
	 */
	String[] getInterfaceNames() {
		return interfaceNames;
	}

	/**
	 * check, if the registration equals a service reference.
	 * 
	 * @param obj
	 *            the object to check.
	 * @return true if the object is equal.
	 * @see java.lang.Object#equals(java.lang.Object)
	 */
	public boolean equals(final Object obj) {
		if (obj instanceof ServiceReference) {
			final ServiceReference ref = (ServiceReference) obj;
			return ref.equals(reference);
		} else if (obj instanceof RemoteServiceRegistration) {
			return ((RemoteServiceRegistration) obj).equals(reference);
		}
		return false;
	}

	/**
	 * get the hash code.
	 * 
	 * @return the hash code.
	 */
	public int hashCode() {
		return (int) (serviceID ^ (serviceID >>> 32));
	}

	/**
	 * get the service object.
	 * 
	 * @return the service object.
	 */
	Object getServiceObject() {
		return serviceObject;
	}

	/**
	 * get a method from the method table.
	 * 
	 * @param signature
	 *            the signature of the method.
	 * @return the Method object.
	 */
	Method getMethod(final String signature) {
		Method method = (Method) methodTable.get(signature);
		// https://bugs.eclipse.org/327029
		if (method == null && signature.startsWith("_rosgi")) {
			final String newsig = signature.substring(6);
			final String firstChar = newsig.substring(0, 1).toLowerCase();
			final String correctedSig = newsig.substring(1);
			method = (Method) methodTable.get(firstChar + correctedSig);
		}
		return method;
	}

	/**
	 * get the DeliverServiceMessage.
	 * 
	 * @return the message.
	 */
	DeliverServiceMessage getDeliverServiceMessage() {
		return deliverServiceMessage;
	}

	public String toString() {
		return "RemoteServiceRegistration{" + reference.toString() + "}"; //$NON-NLS-1$ //$NON-NLS-2$
	}
}