/*
* Mojito Distributed Hash Table (Mojito DHT)
* Copyright (C) 2006-2007 LimeWire LLC
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
*/
package org.limewire.mojito.manager;
import java.net.SocketAddress;
import java.util.Collections;
import java.util.HashMap;
import java.util.Map;
import java.util.Set;
import org.limewire.mojito.Context;
import org.limewire.mojito.KUID;
import org.limewire.mojito.concurrent.DHTFuture;
import org.limewire.mojito.concurrent.DHTFutureTask;
import org.limewire.mojito.concurrent.DHTTask;
import org.limewire.mojito.handler.response.PingResponseHandler;
import org.limewire.mojito.handler.response.PingResponseHandler.PingIterator;
import org.limewire.mojito.result.PingResult;
import org.limewire.mojito.routing.Contact;
import org.limewire.mojito.util.ContactUtils;
/**
* Takes care of concurrent Pings and makes sure
* a single Node cannot be pinged multiple times in parallel.
*/
public class PingManager extends AbstractManager<PingResult> {
private final Map<SocketAddress, PingFuture> futureMap
= Collections.synchronizedMap(new HashMap<SocketAddress, PingFuture>());
public PingManager(Context context) {
super(context);
}
public void init() {
futureMap.clear();
}
/**
* Sends a ping to the remote Host.
*/
public DHTFuture<PingResult> ping(SocketAddress host) {
PingIterator pinger = new PingIteratorFactory.SocketAddressPinger(host);
return ping(null, host, pinger);
}
public DHTFuture<PingResult> pingAddresses(Set<? extends SocketAddress> hosts) {
PingIterator pinger = new PingIteratorFactory.SocketAddressPinger(hosts);
return ping(null, null, pinger);
}
/**
* Sends a ping to the remote Node.
*/
public DHTFuture<PingResult> ping(Contact node) {
PingIterator pinger = new PingIteratorFactory.ContactPinger(node);
return ping(null, node.getContactAddress(), pinger);
}
/**
* Sends a ping to the remote Node.
*/
public DHTFuture<PingResult> ping(KUID nodeId, SocketAddress address) {
PingIterator pinger = new PingIteratorFactory.EntryPinger(nodeId, address);
return ping(null, address, pinger);
}
/**
* Sends a ping to the remote Node.
*/
public DHTFuture<PingResult> ping(Set<? extends Contact> nodes) {
PingIterator pinger = new PingIteratorFactory.ContactPinger(nodes);
return ping(null, null, pinger);
}
/**
* Sends a special ping to the given Node to test if there
* is a Node ID collision.
*/
public DHTFuture<PingResult> collisionPing(Contact node) {
return collisionPing(node.getContactAddress(), Collections.singleton(node));
}
public DHTFuture<PingResult> collisionPing(Set<? extends Contact> nodes) {
return collisionPing(null, nodes);
}
/**
* Sends a special ping to the given Node to test if there
* is a Node ID collision.
*/
private DHTFuture<PingResult> collisionPing(SocketAddress key, Set<? extends Contact> nodes) {
Contact sender = ContactUtils.createCollisionPingSender(context.getLocalNode());
PingIterator pinger = new PingIteratorFactory.CollisionPinger(context, sender, nodes);
return ping(sender, key, pinger);
}
/**
* Sends a ping to the remote Node.
*
* @param sender the local Node
* @param key the remote Node's address
* @param pinger sends ping requests
*/
private DHTFuture<PingResult> ping(Contact sender, SocketAddress key, PingIterator pinger) {
PingFuture future = null;
synchronized (futureMap) {
future = (key != null ? futureMap.get(key) : null);
if (future == null) {
PingResponseHandler handler = new PingResponseHandler(context, sender, pinger);
future = new PingFuture(key, handler);
if (key != null) {
futureMap.put(key, future);
}
context.getDHTExecutorService().execute(future);
}
}
return future;
}
/**
* A ping specific implementation of DHTFuture.
*/
private class PingFuture extends DHTFutureTask<PingResult> {
private final SocketAddress key;
public PingFuture(SocketAddress key, DHTTask<PingResult> handler) {
super(context, handler);
this.key = key;
}
@Override
protected void done0() {
if (key != null) {
futureMap.remove(key);
}
}
}
}