Network.java

/*
SubspaceMobile - A subspace/continuum client for mobile phones
Copyright (C) 2010 Kingsley Masters
Email: kshade2001 at users.sourceforge.net

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 3 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, see <http://www.gnu.org/licenses/>.


REVISIONS:
 */

package com.subspace.network;

import java.io.IOException;
import java.net.*;
import java.nio.ByteBuffer;
import java.nio.ByteOrder;
import java.nio.channels.AsynchronousCloseException;
import java.nio.channels.ClosedByInterruptException;
import java.nio.channels.ClosedChannelException;
import java.nio.channels.DatagramChannel;
import java.nio.channels.NotYetConnectedException;

import android.util.Log;

public abstract class Network implements Runnable {
	private static final boolean LOG_RAW_PACKETS = false;
	protected static final String TAG = "Subspace";
	private static final int MAX_UDP_PACKETSIZE = 512;

	protected INetworkCallback callback;

	private Thread networkThread;
	private DatagramChannel channel;
	private boolean isRunning;
	private boolean isConnected = false;

	private int packetOutCount = 0;
	private int packetInCount = 0;
	private long BytesOut = 0;
	private long BytesIn = 0;

	public Network(INetworkCallback callback) {
		setCallback(callback);
	}

	public final void setCallback(INetworkCallback callback) {
		this.callback = callback;
	}

	protected final void Connect(String host, int port) throws IOException {
		isConnected = false;
		InetSocketAddress remoteHostaddress = new InetSocketAddress(host, port);
		channel = DatagramChannel.open();
		channel.configureBlocking(false);
		channel.connect(remoteHostaddress);

		// woo we are connected
		networkThread = new Thread(this);
		isRunning = true;
		networkThread.start();
		isConnected = true;
	}

	public final void run() {
		ByteBuffer buffer = ByteBuffer.allocateDirect(MAX_UDP_PACKETSIZE);
		buffer.order(ByteOrder.LITTLE_ENDIAN); // subspace uses little endian

		while (isRunning) {
			try {
				buffer.clear();
				int lengthOfData = channel.read(buffer);
				// ignore random empty packets
				if (lengthOfData > 0) {
					// increment packet count
					BytesIn += lengthOfData;
					packetInCount++;
					// flip buffer
					buffer.flip();
					// verbose
					if (LOG_RAW_PACKETS) {
						Log.v(TAG, "R:" + Util.ToHex(buffer));
					}
					// send call back
					callback.Recv(buffer, true);
				}
			} catch (AsynchronousCloseException ioe) {
				Log.v(TAG, "Timeout exceeded, interrupted");
			} catch (ClosedChannelException cce) {
				Log.v(TAG, "Connection Closed by host, no response");
			} catch (PortUnreachableException pue) {
				Log.v(TAG, "Unable to connect, no response");
			} catch (NotYetConnectedException pue) {
				Log.v(TAG, "Unable to connect, no response");
			} catch (Exception ioe) {
				Log.e(TAG, Log.getStackTraceString(ioe));
			}
		}
	}

	protected final void Send(ByteBuffer buffer) throws IOException {
		// wait for connection first
		while (!isConnected) {
			try {
				Thread.sleep(1000);
			} catch (InterruptedException ie) {
				Log.e(TAG, Log.getStackTraceString(ie));
				break;
			}
		}

		if (buffer != null) {
			// rewind
			buffer.rewind();
			// verbose
			if (LOG_RAW_PACKETS) {
				Log.v(TAG, "S:" + Util.ToHex(buffer));
			}
			// write
			int writenBytes = channel.write(buffer);

			// stats
			BytesOut += writenBytes;
			packetOutCount++;
		} else {
			Log.e(TAG, "attempted to send a null buffer");
		}
	}

	protected final void Close() throws IOException {
		isRunning = false;
		channel.disconnect();
		channel.close();
		if (this.networkThread.isAlive()) {
			this.networkThread.interrupt();
		}
	}

	// accessers
	public final int getSentDatagramCount() {
		return packetOutCount;
	}

	public final int getRecvDatagramCount() {
		return packetInCount;
	}
}