OsgiServiceSortedSet.java

/******************************************************************************
 * Copyright (c) 2006, 2010 VMware Inc.
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License v1.0
 * and Apache License v2.0 which accompanies this distribution. 
 * The Eclipse Public License is available at 
 * http://www.eclipse.org/legal/epl-v10.html and the Apache License v2.0
 * is available at http://www.opensource.org/licenses/apache2.0.php.
 * You may elect to redistribute this code under either of these licenses. 
 * 
 * Contributors:
 *   VMware Inc.
 *****************************************************************************/

package org.eclipse.gemini.blueprint.service.importer.support.internal.collection;

import java.util.Comparator;
import java.util.SortedSet;

import org.eclipse.gemini.blueprint.service.importer.support.internal.aop.ServiceProxyCreator;
import org.osgi.framework.BundleContext;
import org.osgi.framework.Filter;

/**
 * OSGi service dynamic collection - allows iterating while the underlying storage is being shrunk/expanded. This
 * collection is read-only - its content is being retrieved dynamically from the OSGi platform.
 * 
 * <p/> This collection and its iterators are thread-safe. That is, multiple threads can access the collection. However,
 * since the collection is read-only, it cannot be modified by the client.
 * 
 * @author Costin Leau
 * 
 */
public class OsgiServiceSortedSet extends OsgiServiceSet implements SortedSet {

	/**
	 * cast the collection to a specialized collection
	 */
	private SortedSet storage;

	private final Comparator comparator;

	public OsgiServiceSortedSet(Filter filter, BundleContext context, ClassLoader classLoader,
			ServiceProxyCreator proxyCreator, boolean useServiceReferences) {
		this(filter, context, classLoader, null, proxyCreator, useServiceReferences);
	}

	public OsgiServiceSortedSet(Filter filter, BundleContext context, ClassLoader classLoader, Comparator comparator,
			ServiceProxyCreator proxyCreator, boolean useServiceReferences) {
		super(filter, context, classLoader, proxyCreator, useServiceReferences);
		this.comparator = comparator;
	}

	protected DynamicCollection createInternalDynamicStorage() {
		storage = new DynamicSortedSet(comparator);
		return (DynamicCollection) storage;
	}

	public Comparator comparator() {
		return storage.comparator();
	}

	public Object first() {
		return storage.first();
	}

	public Object last() {
		return storage.last();
	}

	public SortedSet tailSet(Object fromElement) {
		return storage.tailSet(fromElement);
	}

	public SortedSet headSet(Object toElement) {
		return storage.headSet(toElement);
	}

	public SortedSet subSet(Object fromElement, Object toElement) {
		return storage.subSet(fromElement, toElement);
	}
}