genericpeergroup.java

jxta平台的开发包

/*
 * Copyright (c) 2001-2002 Sun Microsystems, Inc.  All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 *
 * 2. 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.
 *
 * 3. The end-user documentation included with the redistribution,
 *    if any, must include the following acknowledgment:
 *       "This product includes software developed by the
 *       Sun Microsystems, Inc. for Project JXTA."
 *    Alternately, this acknowledgment may appear in the software itself,
 *    if and wherever such third-party acknowledgments normally appear.
 *
 * 4. The names "Sun", "Sun Microsystems, Inc.", "JXTA" and "Project JXTA" must
 *    not be used to endorse or promote products derived from this
 *    software without prior written permission. For written
 *    permission, please contact Project JXTA at http://www.jxta.org.
 *
 * 5. Products derived from this software may not be called "JXTA",
 *    nor may "JXTA" appear in their name, without prior written
 *    permission of Sun.
 *
 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED 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 SUN MICROSYSTEMS OR
 * ITS 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.
 * ====================================================================
 *
 * This software consists of voluntary contributions made by many
 * individuals on behalf of Project JXTA.  For more
 * information on Project JXTA, please see
 * <http://www.jxta.org/>.
 *
 * This license is based on the BSD license adopted by the Apache Foundation.
 *
 * $Id: GenericPeerGroup.java,v 1.119 2006/08/24 19:48:11 bondolo Exp $
 */

package net.jxta.impl.peergroup;

import java.net.URI;
import java.net.URL;
import java.security.cert.Certificate;
import java.util.ArrayList;
import java.util.Collections;
import java.util.Enumeration;
import java.util.Hashtable;
import java.util.Iterator;
import java.util.List;
import java.util.Vector;
import java.util.Map;

import java.io.IOException;
import java.lang.reflect.UndeclaredThrowableException;
import java.util.NoSuchElementException;

import org.apache.log4j.Level;
import org.apache.log4j.Logger;

import net.jxta.access.AccessService;
import net.jxta.discovery.DiscoveryService;
import net.jxta.document.Advertisement;
import net.jxta.document.AdvertisementFactory;
import net.jxta.document.Element;
import net.jxta.document.XMLElement;
import net.jxta.endpoint.EndpointService;
import net.jxta.id.ID;
import net.jxta.id.IDFactory;
import net.jxta.membership.MembershipService;
import net.jxta.peer.PeerID;
import net.jxta.peer.PeerInfoService;
import net.jxta.peergroup.PeerGroup;
import net.jxta.peergroup.PeerGroupID;
import net.jxta.pipe.PipeService;
import net.jxta.platform.JxtaLoader;
import net.jxta.platform.Module;
import net.jxta.platform.ModuleClassID;
import net.jxta.platform.ModuleSpecID;
import net.jxta.protocol.ModuleImplAdvertisement;
import net.jxta.protocol.ConfigParams;
import net.jxta.protocol.PeerAdvertisement;
import net.jxta.protocol.PeerGroupAdvertisement;
import net.jxta.rendezvous.RendezVousService;
import net.jxta.resolver.ResolverService;
import net.jxta.service.Service;

import net.jxta.exception.PeerGroupException;
import net.jxta.exception.ProtocolNotSupportedException;
import net.jxta.exception.ServiceNotFoundException;
import net.jxta.exception.ViolationException;

import net.jxta.impl.loader.RefJxtaLoader;
import net.jxta.impl.protocol.PlatformConfig;
import net.jxta.impl.protocol.PSEConfigAdv;

/**
 *  Provides common services for most peer group implementations.
 **/
public abstract class GenericPeerGroup implements PeerGroup {
    
    /**
     *  Log4J Logger
     **/
    private static final Logger LOG = Logger.getLogger(GenericPeerGroup.class.getName());
    
    /**
     *  The loader - use the getter and setter for modifying the ClassLoader for 
     *  a security manager.
     *
     *  <p/>This should eventually be group scoped rather than implementation
     *  scoped. We are currently allowing classes to loaded into contexts which
     *  they should not be known.
     **/
    private static JxtaLoader loader = new RefJxtaLoader( new URL[0],
            new CompatibilityEquater() {
                public boolean compatible( Element test ) {
                    return StdPeerGroup.isCompatible( test );
                }
            } );
            
    // FIXME 20060217 bondolo We should be loading the class loader with the 
    // net.jxta.impl.config#stdPeerGroupClass moduleImplAdv so that it is used 
    // for peer group instances.
    
    /*
     * Shortcuts to well known services.
     */
    private EndpointService endpoint;
    private ResolverService resolver;
    private DiscoveryService discovery;
    private PipeService pipe;
    private MembershipService membership;
    private RendezVousService rendezvous;
    private PeerInfoService peerinfo;
    private AccessService access;
    
    /**
     * This peer's advertisement in this group.
     **/
    private final PeerAdvertisement peerAdvertisement;
    
    /**
     * This group's advertisement.
     **/
    private PeerGroupAdvertisement peerGroupAdvertisement = null;
    
    /**
     *This group's implAdvertisement.
     **/
    private ModuleImplAdvertisement implAdvertisement = null;
        
    /**
     * This peer's config advertisement.
     **/
    protected ConfigParams configAdvertisement = null;
    
    /**
     * This service implements a group but, being a Service, it runs inside of 
     * some group. That's its home group.
     *
     * <p/>Exception: The platform peer group does not have a parent group. It 
     * has to be entirely self sufficient.
     **/
    protected PeerGroup parentGroup = null;
    
    /**
     *  The location of our store
     **/
    protected URI jxtaHome = null;
    
    /**
     * All the plug-ins that do the work.
     *
     * <p/><ul>
     *      <li>Keys are {@link net.jxta.platform.ModuleClassID}.</li>
     *      <li>Values are {@link net.jxta.service.Service}.</li>
     *  </ul>
     **/
    private final Hashtable<ModuleClassID,Service> services = new Hashtable<ModuleClassID,Service>();
    
    /**
     *  {@code true} when we have decided to stop this group.
     **/
    private volatile boolean stopping = false;
    
    /**
     * {@code true} when the PG adv has been published.
     **/
    private boolean published = false; // assume it hasn't
    
    /**
     * Counts the number of times an interface to this group has been given out.
     * This is decremented everytime an interface object is GCed or
     * its owner calls unref().
     *
     * <p/>When it reaches zero, if it is time to tear-down the group instance;
     * nomatter what the GC thinks. There are threads that need to be stopped
     * before the group instance object ever becomes un-reachable.
     **/
    private int masterRefCount = 0;
    
    /**
     * Is true when at least one interface object has been generated AFTER
     * initComplete has become true. If true, the group stops when its ref
     * count reaches zero.
     **/
    private boolean stopWhenUnreferenced = false;
    
    /**
     * Is set to true when init is completed enough that it makes sense
     * to perform ref-counting.
     **/
    private volatile boolean initComplete = false;
    
    /**
     *  The thread group in which threads created by this group or services of
     *  this group should live.
     **/
    private ThreadGroup threadGroup = null;
    
    /**
     *  {@inheritDoc}
     **/
    public static JxtaLoader getJxtaLoader() {
        return loader;
    }
    
    /**
     * Set a modified version of the Jxta ClassLoader
     **/
    public static void setJxtaLoader(JxtaLoader newLoader) {
        loader = newLoader;
    }
    
    public GenericPeerGroup() {
        // Start building our peer adv.
        peerAdvertisement = (PeerAdvertisement)
        AdvertisementFactory.newAdvertisement(PeerAdvertisement.getAdvertisementType());
    }
    
    /**
     *  {@inheritDoc}
     **/
    public boolean equals( Object target ) {
        
        if( !(target instanceof PeerGroup)) {
            return false;
        }
               
        PeerGroup targetAsPeerGroup = (PeerGroup) target;
        
        // both null or both non-null.
        if((null == parentGroup) && (null != targetAsPeerGroup.getParentGroup())) {
            return false;
        }
        
        if((null != parentGroup) && (null == targetAsPeerGroup.getParentGroup())) {
            return false;
        }
        
        if( (null != parentGroup) && !parentGroup.equals(targetAsPeerGroup.getParentGroup()) ) {
            return false;
        }
        
        // and same peer ids.
        return getPeerGroupID().equals(targetAsPeerGroup.getPeerGroupID());
    }
    
    /**
     *  {@inheritDoc}
     **/
    public int hashCode() {
        // before init we must fail.
        if( (null == peerAdvertisement) || (null == getPeerGroupID()) ) {
            throw new IllegalStateException( "PeerGroup not sufficiently initialized" );
        }
        
        // XXX 20050907 bondolo including parentGroup would improve the hash.
        return getPeerGroupID().hashCode();
    }
    
    /**
     *  {@inheritDoc}
     *  
     *  <p/>An implementation suitable for debugging. <b>Don't try to parse 
     *  this string!</b> All of the information is available from other sources.
     **/
     public String toString() {
        if( null == getPeerGroupID() ) {
            return super.toString();
        }
        
        StringBuffer result = new StringBuffer();
        
        result.append( getPeerGroupID().toString() );
        String peerGroupName = peerGroupAdvertisement.getName();
        if( null != peerGroupName) {
            result.append( " \"" );
            result.append( peerGroupName );
            result.append( '\"' );
        }
        
        if( null != parentGroup ) {
            result.append( " / " );
            result.append( parentGroup.toString() );
        }
        
        return result.toString();
     }
    
    /**
     * Returns the Thread Group in which threads for this peer group will live.
     *
     * @return ThreadGroup
     **/
    public ThreadGroup getHomeThreadGroup() {
        return threadGroup;
    }
    
    // Just a small wrapper around two common idioms that we do use here and
    // there.
    private Enumeration discoverSome(int type,
    String attr,
    String value,
    int seconds,
    Class thisClass) {
        return discoverSome(discovery, type, attr, value, seconds, thisClass);
    }
    
    private Enumeration discoverSome(DiscoveryService discovery,
    int type,
    String attr,
    String value,
    int seconds,
    Class thisClass) {
        
        Vector results = new Vector();
        
        try {
            int count = 0;
            
            Enumeration res;
            
            do {
                res = discovery.getLocalAdvertisements(type, attr, value);
                while (res.hasMoreElements()) {
                    Advertisement a = (Advertisement) res.nextElement();
                    
                    if (thisClass.isInstance(a)) {
                        results.add(a);
                    }
                }
                
                if (results.size() > 0) {
                    break;
                }
                
                if (count % 30 == 0) {
                    discovery.getRemoteAdvertisements(null, type, attr, value, 20);
                }
                
                Thread.sleep(1000);
            } while (count++ < seconds);
        } catch (Exception whatever) {
            if (LOG.isEnabledFor(Level.DEBUG)) {
                LOG.debug("Failure during discovery : ", whatever);
            }
        }
        return results.elements();
    }
    
    private Advertisement discoverOne(int type, String attr, String value, int seconds, Class thisClass) {
        
        Enumeration res = discoverSome(type, attr, value, seconds, thisClass);
        
        if (!res.hasMoreElements()) {
            return null;
        }
        return (Advertisement) res.nextElement();
    }
    
    /*
     * Shortcuts to the standard basic services.
     */
    
    private void setShortCut(ModuleClassID name, Service service) {
        if (endpointClassID.equals(name)) {
            endpoint = (EndpointService) service;
            return;