de.uni.freiburg.iig.telematik.sepia.petrinet.abstr.TimeMachine Maven / Gradle / Ivy

Go to download

Show more of this group Show more artifacts with this name
Show all versions of SEPIA Show documentation

SEPIA provides implementations for various types of Petri nets. Along Place/Transition-nets, it supports Petri nets with distinguishable token colors and defines coloured workflow nets, where coloured tokens are interpreted as data elements used during process execution. To support information flow analysis of processes, SEPIA defines so-called IF-Nets, tailored for security-oriented workflow modeling which enable users to assign security-levels (HIGH, LOW) to transitions, data elements and persons/agents participating in the process execution.

The newest version!

package de.uni.freiburg.iig.telematik.sepia.petrinet.abstr;

import java.util.ArrayList;
import java.util.Collections;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

import de.invation.code.toval.validate.Validate;
import de.uni.freiburg.iig.telematik.sepia.exception.PNException;
import de.uni.freiburg.iig.telematik.sepia.exception.PNValidationException;

public class TimeMachine, 
						 T extends AbstractTransition, 
						 F extends AbstractFlowRelation,
						 M extends AbstractMarking,
						 S extends Object> {

	private double time = 0;
	private PNTimeContext timeContext = null;
	private AbstractPetriNet petriNet = null;
	private Map> pendingActions = new HashMap>();
	
	public TimeMachine(AbstractPetriNet petriNet, PNTimeContext timeContext) {
		super();
		Validate.notNull(petriNet);
		Validate.notNull(timeContext);
		this.petriNet = petriNet;
		this.timeContext = timeContext;
	}
	
	public boolean hasPendingActions(){
		return !pendingActions.isEmpty();
	}
	
	public AbstractPetriNet getPetriNet(){
		return petriNet;
	}
	
	public void reset(){
		time = 0;
		pendingActions.clear();
		petriNet.reset();
	}
	
	public double getTime() {
		return time;
	}
	
	public boolean incTime(){
		if (pendingActions.keySet().size() > 0)
			time = Collections.min(pendingActions.keySet());
		return checkPendingActions();
	}
	
	private boolean checkPendingActions(){
		List actionTimepoints = new ArrayList();
		for (double pendingActionTime : pendingActions.keySet()) {
			if(pendingActionTime <= time){
				actionTimepoints.add(pendingActionTime);
			}
		}
		if(actionTimepoints.isEmpty())
			return false;
		
		Collections.sort(actionTimepoints);
		for (Double actionTimepoint : actionTimepoints) {
			for(TokenConstraint constraint: pendingActions.get(actionTimepoint)){
				petriNet.getPlace(constraint.placeName).addTokens(constraint.tokens);
			}
			pendingActions.remove(actionTimepoint);
		}
		return true;
	}
	
	public void fire(String transitionName) throws PNException{
		Validate.notNull(transitionName);
		petriNet.validateFireTransition(transitionName);
		T transition = petriNet.getTransition(transitionName);
		
		if(!transition.isEnabled())
			throw new PNException("Cannot fire transition "+this+": not enabled");
		try{
			transition.checkValidity();
		} catch(PNValidationException e){
			throw new PNException("Cannot fire transition "+this+": not in valid state ["+e.getMessage()+"]");
		}
		
		for (F r : transition.getIncomingRelations()) {
			r.getPlace().removeTokens(r.getConstraint());
		}
		
		for (F r : transition.getOutgoingRelations()) {
			TokenConstraint newConstraint = new TokenConstraint();
			newConstraint.setPlaceName(r.getPlace().getName());
			newConstraint.setTokens(r.getConstraint());
			double delay = timeContext.getDelayTP(transitionName, r.getPlace().getName());
			putConstraint(delay, newConstraint);
		}
		transition.notifyFiring();
	}
	
	private void putConstraint(double delay, TokenConstraint constraint) {
		double actionTime = time + delay;
		if(!pendingActions.containsKey(actionTime)){
			pendingActions.put(actionTime, new ArrayList());
		}
		pendingActions.get(actionTime).add(constraint);
	}
	
	private class TokenConstraint {
		public String placeName = null;
		public S tokens = null;
		
		public void setPlaceName(String placeName) {
			this.placeName = placeName;
		}
		public void setTokens(S tokens) {
			this.tokens = tokens;
		}
	}
	

}