providers/bundles/org.eclipse.ecf.provider.dnssd/src/org/eclipse/ecf/provider/dnssd/DnsSdServiceTypeID.java

/*******************************************************************************
 * Copyright (c) 2009 Markus Alexander Kuppe.
 * 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:
 *     Markus Alexander Kuppe (ecf-dev_eclipse.org <at> lemmster <dot> de) - initial API and implementation
 ******************************************************************************/
package org.eclipse.ecf.provider.dnssd;

import java.util.ArrayList;
import java.util.Arrays;
import java.util.Collection;
import java.util.HashSet;
import java.util.List;
import java.util.Set;

import org.eclipse.ecf.core.identity.IDCreateException;
import org.eclipse.ecf.core.identity.Namespace;
import org.eclipse.ecf.discovery.identity.IServiceTypeID;
import org.eclipse.ecf.discovery.identity.ServiceTypeID;
import org.xbill.DNS.Lookup;
import org.xbill.DNS.Name;
import org.xbill.DNS.TextParseException;
import org.xbill.DNS.Type;

public class DnsSdServiceTypeID extends ServiceTypeID implements IServiceTypeID {

	private static final long serialVersionUID = 1247933069737880365L;
	
	DnsSdServiceTypeID() {
		super(new DnsSdNamespace());
		scopes = DEFAULT_SCOPE;
		protocols = DEFAULT_PROTO;
		namingAuthority = DEFAULT_NA;
		services = new String[]{""}; //$NON-NLS-1$
	}

	public DnsSdServiceTypeID(Namespace ns, IServiceTypeID id) {
		super(ns, id);
	}

	public DnsSdServiceTypeID(Namespace namespace, String aType)
			throws IDCreateException {
		super(namespace, aType);
	}
	
	DnsSdServiceTypeID(Namespace namespace, Name aName) {
		super(namespace, aName.toString());
	}

	Lookup[] getInternalQueries() {
		String[] protos = protocols;
		int type = Type.SRV;

		String service = null;
		if (services == null || services.length == 0
				|| (services.length == 1 && services[0].equals(""))) { //$NON-NLS-1$
			// if no service is set, create a non service specific query
			service = "_services._dns-sd._"; //$NON-NLS-1$

			// and set proto to "udp" irregardless what has been set
			protos = new String[] { "udp" }; //$NON-NLS-1$

			// and query for PTR records
			type = Type.PTR;
		} else {
			service = "_"; //$NON-NLS-1$
			for (int i = 0; i < services.length; i++) {
				service += services[i];
				service += "._"; //$NON-NLS-1$
			}
		}

		List result = new ArrayList();
		for (int i = 0; i < scopes.length; i++) {
			String scope = scopes[i];
			// remove dangling "."
			if(scope.endsWith(".")) { //$NON-NLS-1$
				scope = scope.substring(0, scope.length() - 1);
			}
			for (int j = 0; j < protos.length; j++) {
				Lookup query;
				try {
					query = new Lookup(service + protos[j] + "." + scope + ".", //$NON-NLS-1$ //$NON-NLS-2$
							type);
				} catch (TextParseException e) {
					continue;
				}
				result.add(query);
			}
		}
		return (Lookup[]) result.toArray(new Lookup[result.size()]);
	}

	/**
	 * @param searchPaths Sets the default search path
	 */
	void setSearchPath(Name[] searchPaths) {
		String[] s = new String[searchPaths.length];
		for(int i = 0; i < searchPaths.length; i++) {
			s[i] = searchPaths[i].toString();
		}
		setSearchPath(s);
	}

	/**
	 * @param searchPaths Sets the default search path
	 */
	void setSearchPath(String[] searchPaths) {
		scopes = searchPaths;
	}

	/**
	 * @return Search scopes used during discovery
	 */
	String[] getSearchPath() {
		return scopes;
	}

	/**
	 * @param additionalSearchPaths Adds the given array to the existing search paths
	 */
	void addSearchPath(String[] additionalSearchPaths) {
	    //convert arrays to collections (lists)
	    Collection coll1 = Arrays.asList(scopes);
	    Collection coll2 = Arrays.asList(additionalSearchPaths);

	    // remove dupes
	    Set s = new HashSet();
	    s.addAll(coll1);
	    s.addAll(coll2);
	    
	    // convert into new scopes
	    scopes = (String[]) s.toArray(new String[s.size()]);
	}
}