001package org.cpsolver.ifs.example.jobshop;
002
003import java.util.Set;
004
005import org.cpsolver.ifs.assignment.Assignment;
006import org.cpsolver.ifs.model.Constraint;
007
008
009/**
010 * Machine constraint. <br>
011 * <br>
012 * Each machine contians a given set of operations (variables). A machine
013 * constraint is satisfied, if all operations on it do not overlap in time.
014 * 
015 * @version IFS 1.3 (Iterative Forward Search)<br>
016 *          Copyright (C) 2006 - 2014 Tomáš Müller<br>
017 *          <a href="mailto:muller@unitime.org">muller@unitime.org</a><br>
018 *          <a href="http://muller.unitime.org">http://muller.unitime.org</a><br>
019 * <br>
020 *          This library is free software; you can redistribute it and/or modify
021 *          it under the terms of the GNU Lesser General Public License as
022 *          published by the Free Software Foundation; either version 3 of the
023 *          License, or (at your option) any later version. <br>
024 * <br>
025 *          This library is distributed in the hope that it will be useful, but
026 *          WITHOUT ANY WARRANTY; without even the implied warranty of
027 *          MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
028 *          Lesser General Public License for more details. <br>
029 * <br>
030 *          You should have received a copy of the GNU Lesser General Public
031 *          License along with this library; if not see
032 *          <a href='http://www.gnu.org/licenses/'>http://www.gnu.org/licenses/</a>.
033 */
034public class Machine extends Constraint<Operation, Location> {
035    private int iMachineNumber = -1;
036
037    /**
038     * Constructor
039     * 
040     * @param machineNumber
041     *            machine number
042     */
043    public Machine(int machineNumber) {
044        super();
045        iMachineNumber = machineNumber;
046    }
047
048    /** Get machine number 
049     * @return machine number
050     **/
051    public int getMachineNumber() {
052        return iMachineNumber;
053    }
054
055    /**
056     * Adds conflicting operations into the set of conflicts.
057     */
058    @Override
059    public void computeConflicts(Assignment<Operation, Location> assignment, Location location, Set<Location> conflicts) {
060        for (Operation o : assignedVariables(assignment)) {
061            if (o.getOperationNumber() == location.variable().getOperationNumber() && o.getJobNumber() == location.variable().getJobNumber())
062                continue;
063            Location conf = assignment.getValue(o);
064            if (conf.overlap(location))
065                conflicts.add(conf);
066        }
067    }
068
069    /**
070     * True if there is an operation from the machine which violates with the
071     * given assignment.
072     */
073    @Override
074    public boolean inConflict(Assignment<Operation, Location> assignment, Location location) {
075        for (Operation o : assignedVariables(assignment)) {
076            if (o.getOperationNumber() == location.variable().getOperationNumber()
077                    && o.getJobNumber() == location.variable().getJobNumber())
078                continue;
079            if (assignment.getValue(o).overlap(location))
080                return true;
081        }
082        return false;
083    }
084
085    /**
086     * True if the two assignments (placement of opeartions of the machine in
087     * time) violates each other.
088     */
089    @Override
090    public boolean isConsistent(Location value1, Location value2) {
091        return !value1.overlap(value2);
092    }
093
094    /** string representation -- for debuging and printing purposes */
095    @Override
096    public String toString() {
097        return getName();
098    }
099
100    /**
101     * Name of the machine (e.g. M10 where 10 is the machine number)
102     */
103    @Override
104    public String getName() {
105        return "M" + iMachineNumber;
106    }
107}