message.java

DTNSim2 is a simulator for Delay-Tolerant Networks (DTNs) written in Java. It is based on Sushant Ja

/**
 * simulator/Message.java
 */
package simulator;

import java.util.ArrayList;

/**
 * A Message send by one node, to be delivered to another node.
 */
public class Message
{
	protected int id = 0;

	protected Node sNode = null;

	protected Node dNode = null;

	protected double creationTime = 0;

	protected int dataLength = 0;

	protected int protocolLength = 0;

	protected boolean isRoutingMessage = false;

	protected ArrayList<Object> headers = null;

	protected ArrayList<History> history = new ArrayList<History>();

	/**
	 * Create a new message.
	 * 
	 * @param id
	 *            a unique integer identifying this message
	 * @param creationTime
	 *            the time this message is created
	 * @param source
	 *            the node that created this message
	 * @param dest
	 *            the node this message is being sent to
	 * @param data
	 *            the size of user data in this message
	 */
	public Message(int id, double creationTime, Node source, Node dest, int data)
	{
		this.id = id;
		this.creationTime = creationTime;
		sNode = source;
		dNode = dest;
		dataLength = data;
	}

	/**
	 * Create a new message.
	 * 
	 * @param id
	 *            a unique integer identifying this message
	 * @param creationTime
	 *            the time this message is created
	 * @param source
	 *            the node that created this message
	 * @param dest
	 *            the node this message is being sent to
	 * @param data
	 *            the size of user data in this message
	 * @param protocol
	 *            the size of protocol data in this message
	 * @param isR
	 *            true if this message is routing message, false otherwise
	 */
	public Message(int id, double creationTime, Node source, Node dest, int data, int protocol, boolean isR)
	{
		this(id, creationTime, source, dest, data);

		protocolLength = protocol;
		isRoutingMessage = isR;
	}

	public Message(Message org)
	{
		id = org.id;
		creationTime = org.creationTime;
		sNode = org.sNode;
		dNode = org.dNode;
		dataLength = org.dataLength;
		protocolLength = org.protocolLength;
		isRoutingMessage = org.isRoutingMessage;

		if (org.headers != null)
			headers = new ArrayList<Object>(org.headers);

		history = new ArrayList<History>(org.history);
	}

	public boolean update(Message from)
	{
		if (from.creationTime > creationTime)
		{
			id = from.id;
			creationTime = from.creationTime;
			headers = from.headers;
			history = from.history;

			return true;
		}

		return false;
	}

	public String toString()
	{
		if (id >= 0)
		{
			if (isRoutingMessage)
				return "MSG_" + id + "_R_";

			return "MSG_" + id + "_";
		}
		else
		{
			if (isRoutingMessage)
				return "ACK_" + (-id) + "_R_";

			return "ACK_" + (-id) + "_";
		}
	}

	public int getId()
	{
		return id;
	}

	public double getCreationTime()
	{
		return creationTime;
	}

	public void setSourceNode(Node nSN)
	{
		sNode = nSN;
	}

	public Node getSourceNode()
	{
		return sNode;
	}

	public void setDestNode(Node nDN)
	{
		dNode = nDN;
	}

	public Node getDestNode()
	{
		return dNode;
	}

	public void setDataLength(int nLen)
	{
		if (nLen >= 0)
			dataLength = nLen;
	}

	public final int getDataLength()
	{
		return dataLength;
	}

	public void setProtocolLength(int nLen)
	{
		if (nLen >= 0)
			protocolLength = nLen;
	}

	public final int getProtocolLength()
	{
		return protocolLength;
	}

	// public static final int INTEGER_LENGTH = 4;

	public final int getLength()
	{
		return protocolLength + dataLength;
	}

	/**
	 * Represents a unique message header. Create an instance of this class to
	 * use as a key to store data in a message. This allows multiple objects to
	 * store data in a message without conflicts.
	 */
	public static class Header
	{
		private static int nextIdx = 0;

		private int idx = -1;

		public Header()
		{
			idx = nextIdx++;
		}

		public int idx()
		{
			return idx;
		}
	}

	/**
	 * Get the data associated with the header key. This returns null if there
	 * is no such data stored. The key cannot be null.
	 * 
	 * @throws NullPointerException
	 *             if the key is null.
	 */
	public Object getData(Header key)
	{
		if (key == null)
			throw new NullPointerException("the key cannot be null");

		int idx = key.idx();

		if (headers == null || headers.size() <= idx)
			return null;

		return headers.get(idx);
	}

	/**
	 * Stores the data in this message, and associates it with the header key.
	 * If data was already stored with the same key in this message, it will be
	 * replaced. Neither the key or the data can be null.
	 * 
	 * @throws NullPointerException
	 *             if the key or data is null.
	 */
	public void storeData(Header key, Object data)
	{
		if (key == null)
			throw new NullPointerException("the key cannot be null");

		if (data == null)
			throw new NullPointerException("the data cannot be null");

		int idx = key.idx();

		if (headers == null)
		{
			headers = new ArrayList<Object>(idx + 1);
		}

		while (headers.size() <= idx)
			headers.add(null);

		headers.set(idx, data);
	}

	public void removeData(Header key)
	{
		if (key == null)
			throw new NullPointerException("the key cannot be null");

		int idx = key.idx();

		if (headers == null || headers.size() <= idx)
			return;

		headers.set(idx, null);
	}

	public void setIsRoutingMessage(boolean isR)
	{
		isRoutingMessage = isR;
	}

	public final boolean isRoutingMessage()
	{
		return isRoutingMessage;
	}

	public ArrayList<History> getHistory()
	{
		return history;
	}

	public void addHistory(double time, Contact ct)
	{
		history.add(new History(time, ct));
	}

	public class History
	{
		double timeSent;

		Contact contact;

		public History(double time, Contact c)
		{
			contact = c;
			timeSent = time;
		}

		public String toString()
		{
			return "{" + timeSent + ":" + contact + "}";
		}
	}
}