/*
* Copyright (c) 2009-2012 jMonkeyEngine
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are
* met:
*
* * Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
*
* * 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.
*
* * Neither the name of 'jMonkeyEngine' nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS 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 THE COPYRIGHT OWNER OR
* 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.
*/
package com.jme3.network.base;
import com.jme3.network.Filter;
import com.jme3.network.HostedConnection;
import com.jme3.network.Message;
import com.jme3.network.MessageListener;
import com.jme3.network.kernel.Endpoint;
import com.jme3.network.kernel.EndpointEvent;
import com.jme3.network.kernel.Envelope;
import com.jme3.network.kernel.Kernel;
import com.jme3.network.message.ClientRegistrationMessage;
import java.nio.ByteBuffer;
import java.util.Map;
import java.util.concurrent.ConcurrentHashMap;
import java.util.concurrent.atomic.AtomicBoolean;
import java.util.logging.Level;
import java.util.logging.Logger;
/**
* Wraps a single Kernel and forwards new messages
* to the supplied message dispatcher and new endpoint
* events to the connection dispatcher. This is used
* by DefaultServer to manage its kernel objects.
*
* <p>This adapter assumes a simple protocol where two
* bytes define a (short) object size with the object data
* to follow. Note: this limits the size of serialized
* objects to 32676 bytes... even though, for example,
* datagram packets can hold twice that. :P</p>
*
* @version $Revision$
* @author Paul Speed
*/
public class KernelAdapter extends Thread
{
static Logger log = Logger.getLogger(KernelAdapter.class.getName());
private DefaultServer server; // this is unfortunate
private Kernel kernel;
private MessageListener<HostedConnection> messageDispatcher;
private AtomicBoolean go = new AtomicBoolean(true);
// Keeps track of the in-progress messages that are received
// on reliable connections
private Map<Endpoint, MessageProtocol> messageBuffers = new ConcurrentHashMap<Endpoint,MessageProtocol>();
// Marks the messages as reliable or not if they came
// through this connector.
private boolean reliable;
public KernelAdapter( DefaultServer server, Kernel kernel, MessageListener<HostedConnection> messageDispatcher,
boolean reliable )
{
super( String.valueOf(kernel) );
this.server = server;
this.kernel = kernel;
this.messageDispatcher = messageDispatcher;
this.reliable = reliable;
setDaemon(true);
}
public Kernel getKernel()
{
return kernel;
}
public void initialize()
{
kernel.initialize();
}
public void broadcast( Filter<? super Endpoint> filter, ByteBuffer data, boolean reliable,
boolean copy )
{
kernel.broadcast( filter, data, reliable, copy );
}
public void close() throws InterruptedException
{
go.set(false);
// Kill the kernel
kernel.terminate();
join();
}
protected void reportError( Endpoint p, Object context, Exception e )
{
// Should really be queued up so the outer thread can
// retrieve them. For now we'll just log it. FIXME
log.log( Level.SEVERE, "Unhandled error, endpoint:" + p + ", context:" + context, e );
if( p.isConnected() ) {
// In lieu of other options, at least close the endpoint
p.close();
}
}
protected HostedConnection getConnection( Endpoint p )
{
return server.getConnection(p);
}
protected void connectionClosed( Endpoint p )
{
// Remove any message buffer we've been accumulating
// on behalf of this endpoing
messageBuffers.remove(p);
log.log( Level.FINE, "Buffers size:{0}", messageBuffers.size() );
server.connectionClosed(p);
}
/**
* Note on threading for those writing their own server
* or adapter implementations. The rule that a single connection be
* processed by only one thread at a time is more about ensuring that
* the messages are delivered in the order that they are received
* than for any user-code safety. 99% of the time the user code should
* be writing for multithreaded access anyway.
*
* <p>The issue with the messages is that if a an implementation is
* using a general thread pool then it would be possible for a
* naive implementation to have one thread grab an Envelope from
* connection 1's and another grab the next Envelope. Since an Envelope
* may contain several messages, delivering the second thread's messages
* before or during the first's would be really confusing and hard
* to code for in user code.</p>
*
* <p>And that's why this note is here. DefaultServer does a rudimentary
* per-connection locking but it couldn't possibly guard against
* out of order Envelope processing.</p>
*/
protected void dispatch( Endpoint p, Message m )
{
// Because this class is the only one with the information
// to do it... we need to pull of the registration message
// here.
if( m instanceof ClientRegistrationMessage ) {
server.registerClient( this, p, (ClientRegistrationMessage)m );
return;
}
try {
HostedConnection source = getConnection(p);
if( source == null ) {
if( reliable ) {
// If it's a reliable connection then it's slightly more
// concerning but this can happen all the time for a UDP endpoint.
log.log( Level.WARNING, "Recieved message from unconnected endpoint:" + p + " message:" + m );
}
return;
}
messageDispatcher.messageReceived( source, m );
} catch( Exception e ) {
reportError(p, m, e);
}
}
protected MessageProtocol getMessageBuffer( Endpoint p )
{
if( !reliable ) {
// Since UDP comes in packets and they aren't split
// up, there is no reason to buffer. In fact, there would
// be a down side because there is no way for us to reliably
// clean these up later since we'd create another one for
// any random UDP packet that comes to the port.
return new MessageProtocol();
} else {
// See if we already have one
MessageProtocol result = messageBuffers.get(p);
if( result == null ) {
result = new MessageProtocol();
messageBuffers.put(p, result);
}
return result;
}
}
protected void createAndDispatch( Envelope env )
{
MessageProtocol protocol = getMessageBuffer(env.getSource());
byte[] data = env.getData();
ByteBuffer buffer = ByteBuffer.wrap(data);
int count = protocol.addBuffer( buffer );
if( count == 0 ) {
// This can happen if there was only a partial message
// received. However, this should never happen for unreliable
// connections.
if( !reliable ) {
// Log some additional information about the packet.
int len = Math.min( 10, data.length );
StringBuilder sb = new StringBuilder();
for( int i = 0; i < len; i++ ) {
sb.append( "[" + Integer.toHexString(data[i]) + "]" );
}
log.log( Level.FINE, "First 10 bytes of incomplete nessage:" + sb );
throw new RuntimeException( "Envelope contained incomplete data:" + env );
}
}
// Should be complete... and maybe we should check but we don't
Message m = null;
while( (m = protocol.getMessage()) != null ) {
m.setReliable(reliable);
dispatch( env.getSource(), m );
}
}
protected void createAndDispatch( EndpointEvent event )
{
// Only need to tell the server about disconnects
if( event.getType() == EndpointEvent.Type.REMOVE ) {
connectionClosed( event.getEndpoint() );
}
}
protected void flushEvents()
{
EndpointEvent event;
while( (event = kernel.nextEvent()) != null ) {
try {
createAndDispatch( event );
} catch( Exception e ) {
reportError(event.getEndpoint(), event, e);
}
}
}
public void run()
{
while( go.get() ) {
try {
// Check for pending events
flushEvents();
// Grab the next envelope
Envelope e = kernel.read();
if( e == Kernel.EVENTS_PENDING )
continue; // We'll catch it up above
// Check for pending events that might have
// come in while we were blocking. This is usually
// when the connection add events come through
flushEvents();
try {
createAndDispatch( e );
} catch( Exception ex ) {
reportError(e.getSource(), e, ex);
}
} catch( InterruptedException ex ) {
if( !go.get() )
return;
throw new RuntimeException( "Unexpected interruption", ex );
}
}
}
}