/*
* Copyright 2004-2006 the original author or authors.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package net.sf.cindy.session.nio;
import java.io.IOException;
import java.net.DatagramSocket;
import java.net.SocketAddress;
import java.nio.ByteBuffer;
import java.nio.channels.DatagramChannel;
import java.nio.channels.SelectableChannel;
import net.sf.cindy.Buffer;
import net.sf.cindy.Packet;
import net.sf.cindy.SessionType;
import net.sf.cindy.buffer.BufferFactory;
import net.sf.cindy.packet.DefaultPacket;
import net.sf.cindy.session.nio.reactor.ReactorHandler;
import net.sf.cindy.util.ChannelUtils;
import net.sf.cindy.util.Configuration;
/**
* Datagram channel session.
*
* @author <a href="chenrui@gmail.com">Roger Chen</a>
* @version $id$
*/
public class DatagramChannelSession extends AbstractChannelSession {
private DatagramChannel channel;
public DatagramSocket getSocket() {
DatagramChannel dc = channel;
if (dc == null)
return null;
return dc.socket();
}
public SessionType getSessionType() {
return SessionType.UDP;
}
public SocketAddress getRemoteAddress() {
if (isStarted())
return channel.socket().getRemoteSocketAddress();
return super.getRemoteAddress();
}
public SocketAddress getLocalAddress() {
if (isStarted())
return channel.socket().getLocalSocketAddress();
return super.getLocalAddress();
}
/**
* Set the datagram channel which the session will used.
*
* @param channel
* datagram channel
* @throws IllegalStateException
*/
public void setChannel(DatagramChannel channel) {
if (isStarted())
throw new IllegalStateException(
"can't set datagram channel after session started");
this.channel = channel;
}
/**
* Get datagram channel associted with the session.
*
* @return datagram channel
*/
public DatagramChannel getChannel() {
return channel;
}
protected ReactorHandler getReactorHandler() {
return new ChannelReactorHandler() {
public SelectableChannel[] getChannels() {
return new SelectableChannel[] { channel };
}
protected void read() throws IOException {
while (true) {
Buffer buffer = BufferFactory.allocate(getReadPacketSize());
ByteBuffer byteBuffer = buffer.asByteBuffer();
try {
SocketAddress address = channel.receive(byteBuffer);
if (address == null) {
buffer.release();
break;
}
buffer.limit(byteBuffer.position());
getSessionFilterChain(false).packetReceived(
new DefaultPacket(buffer, address));
} catch (IOException e) {
buffer.release();
throw e;
}
}
}
private boolean isConnected() {
if (channel == null)
return false;
return channel.isConnected();
}
protected void checkSendPacket(Packet packet) {
if (!isConnected() && packet.getAddress() == null)
throw new RuntimeException(
"can't send packet to unconnected datagram channel without socket address");
}
protected boolean write(Packet packet) throws IOException {
Buffer buffer = packet.getContent();
int writeCount = 0;
if (packet.getAddress() == null) // connected
writeCount = buffer.write(channel);
else {
writeCount = channel.send(buffer.asByteBuffer(), packet
.getAddress());
buffer.skip(writeCount);
}
return writeCount != 0;
}
};
}
protected void doStart() throws IOException {
if (channel != null)
return;
try {
channel = DatagramChannel.open();
DatagramSocket socket = channel.socket();
int recvBufferSize = Configuration.getRecvBufferSize();
if (recvBufferSize > 0)
socket.setReceiveBufferSize(recvBufferSize);
int sendBufferSize = Configuration.getSendBufferSize();
if (sendBufferSize > 0)
socket.setSendBufferSize(sendBufferSize);
socket.setReuseAddress(Configuration.isReuseSessionAddress());
channel.socket().bind(getLocalAddress());
if (getRemoteAddress() != null)
channel.connect(getRemoteAddress());
} catch (IOException e) {
doClose();
throw e;
}
}
protected void doClose() {
ChannelUtils.close(channel);
channel = null;
}
}