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package com.jme3.network.kernel.udp;
import com.jme3.network.Filter;
import com.jme3.network.kernel.*;
import java.io.IOException;
import java.net.*;
import java.nio.ByteBuffer;
import java.util.Map;
import java.util.concurrent.ConcurrentHashMap;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;
import java.util.concurrent.atomic.AtomicBoolean;
import java.util.logging.Level;
import java.util.logging.Logger;
/**
* A Kernel implementation using UDP packets.
*
* @version $Revision$
* @author Paul Speed
*/
public class UdpKernel extends AbstractKernel
{
private static final Logger log = Logger.getLogger(UdpKernel.class.getName());
private InetSocketAddress address;
private HostThread thread;
private ExecutorService writer;
// The nature of UDP means that even through a firewall,
// a user would have to have a unique address+port since UDP
// can't really be NAT'ed.
private Map socketEndpoints = new ConcurrentHashMap<>();
public UdpKernel( InetAddress host, int port )
{
this( new InetSocketAddress(host, port) );
}
public UdpKernel( int port ) throws IOException
{
this( new InetSocketAddress(port) );
}
public UdpKernel( InetSocketAddress address )
{
this.address = address;
}
protected HostThread createHostThread()
{
return new HostThread();
}
@Override
public void initialize()
{
if( thread != null )
throw new IllegalStateException( "Kernel already initialized." );
writer = Executors.newFixedThreadPool(2, new NamedThreadFactory(toString() + "-writer"));
thread = createHostThread();
try {
thread.connect();
thread.start();
} catch( IOException e ) {
throw new KernelException( "Error hosting:" + address, e );
}
}
@Override
public void terminate() throws InterruptedException
{
if( thread == null )
throw new IllegalStateException( "Kernel not initialized." );
try {
thread.close();
writer.shutdown();
thread = null;
// Need to let any caller waiting for a read() wakeup
wakeupReader();
} catch( IOException e ) {
throw new KernelException( "Error closing host connection:" + address, e );
}
}
/**
* Dispatches the data to all endpoints managed by the
* kernel. 'routing' is currently ignored.
*/
@Override
public void broadcast( Filter filter, ByteBuffer data, boolean reliable,
boolean copy )
{
if( reliable )
throw new UnsupportedOperationException( "Reliable send not supported by this kernel." );
if( copy ) {
// Copy the data just once
byte[] temp = new byte[data.remaining()];
System.arraycopy(data.array(), data.position(), temp, 0, data.remaining());
data = ByteBuffer.wrap(temp);
}
// Hand it to all of the endpoints that match our routing
for( UdpEndpoint p : socketEndpoints.values() ) {
// Does it match the filter?
if( filter != null && !filter.apply(p) )
continue;
// Send the data
p.send( data );
}
}
protected Endpoint getEndpoint( SocketAddress address, boolean create )
{
UdpEndpoint p = socketEndpoints.get(address);
if( p == null && create ) {
p = new UdpEndpoint( this, nextEndpointId(), address, thread.getSocket() );
socketEndpoints.put( address, p );
// Add an event for it.
addEvent( EndpointEvent.createAdd( this, p ) );
}
return p;
}
/**
* Called by the endpoints when they need to be closed.
*/
protected void closeEndpoint( UdpEndpoint p ) throws IOException
{
// Just book-keeping to do here.
if( socketEndpoints.remove( p.getRemoteAddress() ) == null )
return;
log.log( Level.FINE, "Closing endpoint:{0}.", p );
log.log( Level.FINE, "Socket endpoints size:{0}", socketEndpoints.size() );
addEvent( EndpointEvent.createRemove( this, p ) );
wakeupReader();
}
protected void newData( DatagramPacket packet )
{
// So the tricky part here is figuring out the endpoint and
// whether it's new or not. In these UDP schemes, firewalls have
// to be ported back to a specific machine, so we will consider
// the address + port (ie: SocketAddress) the de facto unique
// ID.
Endpoint p = getEndpoint( packet.getSocketAddress(), true );
// We'll copy the data to trim it.
byte[] data = new byte[packet.getLength()];
System.arraycopy(packet.getData(), 0, data, 0, data.length);
Envelope env = new Envelope( p, data, false );
addEnvelope( env );
}
protected void enqueueWrite( Endpoint endpoint, DatagramPacket packet )
{
writer.execute( new MessageWriter(endpoint, packet) );
}
protected class MessageWriter implements Runnable
{
private Endpoint endpoint;
private DatagramPacket packet;
public MessageWriter( Endpoint endpoint, DatagramPacket packet )
{
this.endpoint = endpoint;
this.packet = packet;
}
@Override
public void run()
{
// Not guaranteed to always work but an extra datagram
// to a dead connection isn't so big of a deal.
if( !endpoint.isConnected() ) {
return;
}
try {
thread.getSocket().send(packet);
} catch( Exception e ) {
KernelException exc = new KernelException( "Error sending datagram to:" + address, e );
exc.fillInStackTrace();
reportError(exc);
}
}
}
protected class HostThread extends Thread
{
private DatagramSocket socket;
private AtomicBoolean go = new AtomicBoolean(true);
private byte[] buffer = new byte[65535]; // slightly bigger than needed.
public HostThread()
{
setName( "UDP Host@" + address );
setDaemon(true);
}
protected DatagramSocket getSocket()
{
return socket;
}
public void connect() throws IOException
{
socket = new DatagramSocket( address );
log.log( Level.FINE, "Hosting UDP connection:{0}.", address );
}
public void close() throws IOException, InterruptedException
{
// Set the thread to stop
go.set(false);
// Make sure the channel is closed
socket.close();
// And wait for it
join();
}
@Override
public void run()
{
log.log( Level.FINE, "Kernel started for connection:{0}.", address );
// An atomic is safest and costs almost nothing.
while( go.get() ) {
try {
// Could reuse the packet, but I don't see the
// point, and it may lead to subtle bugs if not properly
// reset.
DatagramPacket packet = new DatagramPacket( buffer, buffer.length );
socket.receive(packet);
newData( packet );
} catch( IOException e ) {
if( !go.get() )
return;
reportError( e );
}
}
}
}
}
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