pheromoneagent.java

P2P模拟器P2Psim的程序源码

package graph;

import org.jgraph.graph.DefaultGraphCell;
import org.jgraph.graph.DefaultEdge;
import org.jgraph.graph.GraphConstants;

import java.io.Serializable;

import java.util.Iterator;

/*
 * PheromoneAgent:
 * 	the agent starts in a vertex, and has status = MOVING
 *	in the next step, the agent finds out if he has a pheromone pointing to
 *	the right resource. If this is the case, he uses it and follows the path. Otherwise, he finds the 
 *	best node, based on the pheromones found in neighbouring nodes, only one hop away. 
 *	When a pheromone is used, its strength is
 *	decreased. The agent jumps on the connecting edge, and gets the 
 * 	status MOVING. When the agent reaches another node, status is changed to
 *	SEARCHING. When the resource is not found, status is changed to EXPLORING, and
 *	the same procedure is followed, as explained above. 
 *	When the resource is found, status is changed to RETURNING
 *	and the next node is chosen, based on the gradient-field, constructed from
 *	the origin. When there is no gradient-field, a random node is chosen as the
 *	successor. While returning, a pheromone is dropped, or an existing pheromone is
 *	strenghtend. The existing pheromone is only strenghtened when the previousNode of
 *	the agent equals the node the pheromone is pointing to. 
 */
 
public class PheromoneAgent extends Agent implements Serializable
{
	public PheromoneAgent(DefaultGraphCell origin, ResourceQuery searchFor)
	{
		super(origin, searchFor);
	}
	
	public void run(DefaultGraphCell currentGraphCell)
	{
		age++;
		
		Properties properties = GraphEventManager.getReference().getProperties(currentGraphCell);
		
		// Ant bevindt zich op een edge
		if (currentGraphCell instanceof DefaultEdge)
		{
			if (status == MOVING)
			{
				int capacity = GraphEventManager.getReference().getEdgeProperties((DefaultEdge)currentGraphCell).getCapacity();
				if (progress >= 1)
				{
					// We zijn aan de volgende knoop
					
					//Spring van de edge
					properties.removeInformation("Agents", this);
					
					//Kruip in de volgende vertex
					GraphEventManager.getReference().getProperties(nextNode).addInformation("Agents", this);
					status = SEARCHING;
				}
				else
				{
					progress = Math.min (1, progress + (0.05 * capacity));
				}
			}
			else if (status == RETURNING)
			{
				int capacity = GraphEventManager.getReference().getEdgeProperties((DefaultEdge)currentGraphCell).getCapacity();
				if (progress >= 1)
				{
					// We zijn aan de volgende knoop
		
					//Spring van de edge
					properties.removeInformation("Agents", this);
		
					//Kruip in de volgende vertex
					GraphEventManager.getReference().getProperties(nextNode).addInformation("Agents", this);
					status = RETURNING;
				}
				else
				{
					progress = Math.min (1, progress + (0.05 * capacity));
				}
			}
		}
		// Ant bevindt zich in een vertex
		else
		{
			if (status == MOVING)
			{
				//System.out.println("PheromoneAgent :: run : MOVING");
				properties.removeInformation("Agents", this);
				DefaultEdge newEdge = GraphEventManager.getReference().eventGetConnectingEdge(previousNode, nextNode);
				//System.out.println(newEdge);
				
				//System.out.print("van " + ((DefaultGraphCell)((DefaultPort)newEdge.getSource()).getParent()) + " naar  ");
				//System.out.println(((DefaultGraphCell)((DefaultPort)newEdge.getTarget()).getParent()));
				
				Properties edgeProperties = (Properties)GraphConstants.getValue(newEdge.getAttributes());
				edgeProperties.addInformation("Agents", this);
			}
			
			if (status == SEARCHING)
			{
				//System.out.println("Search for resource");
				Properties currentNodeProperties = (Properties)GraphConstants.getValue(nextNode.getAttributes());
				
				if (currentNodeProperties.getListInformation("Resources") != null)
				{		
					Iterator li = currentNodeProperties.getListInformation("Resources").iterator();
					
					while (li.hasNext())
					{
						if (((Resource)li.next()).getName().equals(searchFor.getSearchFor()))
						{
							System.out.println("Found !  (in " + currentNodeProperties.getName() + ")");
							previousNode = currentGraphCell;
							status = RETURNING;
							/*
							DefaultEdge returningEdge = GraphEventManager.getReference().getConnectingEdge(previousNode, nextNode);
							DefaultGraphCell tempCell = nextNode;
							nextNode = previousNode;
							previousNode = tempCell;
							
							GraphEventManager.getReference().getProperties(returningEdge).addInformation("Agents", this);
							GraphEventManager.getReference().getProperties(previousNode).removeInformation("Agents", this);
							*/
						}
					}
					if (status != RETURNING)
					{
						// dus resource is niet gevonden
						//System.out.println("Not found :-(");
						status = EXPLORING;
					}
				}
				else
				{	
					//System.out.println("No resources ...");
					status = EXPLORING;
				}
			}
			
			if (status == EXPLORING)
			{
				// we zitten in next_node, wat is de volgende stap ?
				//System.out.println("Exploring: looking for next node");
				
				// Is er lokaal een pheromoon aanwezig dat aangeeft langs waar het is ?
				Iterator pheromoneIterator = GraphEventManager.getReference().getProperties(currentGraphCell).getInformation("Pheromones");
				Pheromone tempPheromone = null;
				Pheromone tempPheromone2 = null;
				boolean followpath = false;
				int strength = 0;
				
				if (pheromoneIterator != null)
				{
					while (pheromoneIterator.hasNext())
					{
						tempPheromone = (Pheromone)pheromoneIterator.next();
						//System.out.println("Gradient met source: " + tempGradient.getSource() + " =?= " + origin );
						if (tempPheromone.getResource().equals(searchFor.getSearchFor()))
						{
							if (tempPheromone.getDirection() != null)
							{
								if (tempPheromone.getStrength() > strength)
								{
									strength = tempPheromone.getStrength();
									nextNode = tempPheromone.getDirection();
									tempPheromone2 = tempPheromone;
									followpath = true;	
								}
							}
						}
					}
					if (tempPheromone2 != null)
					{
						tempPheromone2.decrease();
					}
				}
				
				if (tempPheromone2 != null && tempPheromone2.getStrength() == 0)
				{
					GraphEventManager.getReference().getProperties(currentGraphCell).removeInformation("Pheromones", tempPheromone2);		
				}
				
				// geen lokaal pheromoon, zoek er een in een nabijliggende knoop.
				if (! followpath)
				{
					Iterator connectedNodesIterator = GraphEventManager.getReference().getConnectedNodes(currentGraphCell).iterator();
						
					int maxPheromone = 0;
					DefaultGraphCell tempCell;
	
					while (connectedNodesIterator.hasNext())
					{
						tempCell = (DefaultGraphCell)connectedNodesIterator.next();
		
						pheromoneIterator = GraphEventManager.getReference().getProperties(tempCell).getInformation("Pheromones");
		
						if (pheromoneIterator != null)
						{
							while (pheromoneIterator.hasNext())
							{
								tempPheromone = (Pheromone)pheromoneIterator.next();
								//System.out.println("Gradient met source: " + tempGradient.getSource() + " =?= " + origin );
								if (tempPheromone.getResource().equals(searchFor.getSearchFor())
									&& tempPheromone.getDirection() == previousNode)
								{
									if (tempPheromone.getStrength() > maxPheromone)
									{
										maxPheromone = tempPheromone.getStrength();
										nextNode = tempCell;
									}	
								}
							}
						}
					}
	
					if (maxPheromone == 0) 
					{
						//Neem willekeurige node.
						nextNode = getRandomGraphCellFromExcept(currentGraphCell, previousNode);
						//System.out.println("properties edge van " + currentGraphCell + " to " + nextNode);
					}
				}
				
				progress = 0;
				previousNode = currentGraphCell;
				//System.out.println("properties edge van " + previousNode + " to " + nextNode);
				
				GraphEventManager.getReference().getProperties(currentGraphCell).removeInformation("Agents", this);
				setStatus(Agent.MOVING);
				
				if (GraphEventManager.getReference().getConnectingEdge(previousNode, nextNode) == null)
				{
					setStatus(Agent.DEAD);