de.uni.freiburg.iig.telematik.sepia.petrinet.abstr.AbstractMarking 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.io.Serializable;
import java.util.HashMap;
import java.util.Map;
import java.util.Set;

import de.invation.code.toval.validate.Validate;


/**
 * This class defines a Petri net state in form of a marking.

 * Markings hold the state (number and kind of tokens) for all net places.

 * Each place state is defined with a token representation of type M.
 * 
 * @author Thomas Stocker
 *
 * @param  Token representation type for places.
 */
public abstract class AbstractMarking implements Serializable{
	
	private static final long serialVersionUID = -8258625737221734181L;
	/**
	 * Map for place states, indexed with place-names.

	 * Each place state is defined with a token representation of type M.
	 */
	protected Map placeStates = new HashMap(); 
	
	
	//------- Basic properties -----------------------------------------------------------------------
	
	/**
	 * Returns all places for which the marking contains a state.
	 * @return The set of places with states in the marking.
	 */
	public Set places(){
		return placeStates.keySet();
	}
	
	/**
	 * Checks if the marking contains a state for the given place.
	 * @param place The place of interest.
	 * @return true if the marking contains a states for the given place;

	 * false otherwise.
	 */
	public boolean contains(String place) {
		return placeStates.keySet().contains(place);
	}
	
	/**
	 * Removes the state for the given place from the marking if it contains a state for the place.
	 * @param place The place whose state has to be removed.
	 */
	public void remove(String place){
		placeStates.remove(place);
	}
	
	/**
	 * Indicates if the marking is empty, i.e. contains no place states.
	 * @return true if the marking is empty;

	 * false otherwise.
	 */
	public boolean isEmpty(){
		return placeStates.isEmpty();
	}
	
	/**
	 * Clears the marking, i.e. removes all states for all places.
	 */
	public void clear(){
		placeStates.clear();
	}
	
	
	//------- State methods --------------------------------------------------------------------------
	
	/**
	 * Returns the state of the given place within the marking.
	 * @param place The place whose state is requested.
	 * @return The state of the given place in the marking.
	 */
	public S get(String place){
		validatePlace(place);
		return placeStates.get(place);
	}
	
	/**
	 * Sets the state of the given place in the marking.
	 * @param place The place whose state is set.
	 * @param state The state for the given place.
	 */
	public void set(String place, S state){
		validatePlace(place);
		validateState(state);
		placeStates.put(place, state);
	}
	
	
	//------- Validation methods ---------------------------------------------------------------------
	
	/**
	 * Validates a place for which a state has to be set.
	 * @param place The place whose state is set.
	 */
	protected void validatePlace(String place){
		Validate.notNull(place);
	}
	
	/**
	 * Validates a state which has to be set for a place.
	 * @param state The state which has to be set.
	 */
	protected void validateState(S state){
		Validate.notNull(state);
	}
	
	
	//------- clone, hashCode and equals ---------------------------------------------------------------------
	
	/**
	 * Returns a copy of the marking.

	 * Depending on M, this may require different routines, which have to be implemented by subclasses.
	 */
	@Override
	public abstract AbstractMarking clone();
	
	@Override
	public int hashCode() {
		final int prime = 37;
		int result = 1;
		result = prime * result + ((placeStates == null) ? 0 : placeStates.hashCode());
		return result;
	}

	@Override
	public boolean equals(Object obj) {
		if (this == obj)
			return true;
		if (obj == null)
			return false;
		if (getClass() != obj.getClass())
			return false;
		@SuppressWarnings("unchecked")
		AbstractMarking other = (AbstractMarking) obj;
		if (placeStates == null) {
			if (other.placeStates != null)
				return false;
		} else if (!placeStates.equals(other.placeStates))
			return false;
		return true;
	}
	
}