    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 * @author  Tomáš Müller
    016 * @version IFS 1.3 (Iterative Forward Search)<br>
    017 *          Copyright (C) 2006 - 2014 Tomáš Müller<br>
    018 *          <a href="mailto:muller@unitime.org">muller@unitime.org</a><br>
    019 *          <a href="http://muller.unitime.org">http://muller.unitime.org</a><br>
    020 * <br>
    021 *          This library is free software; you can redistribute it and/or modify
    022 *          it under the terms of the GNU Lesser General Public License as
    023 *          published by the Free Software Foundation; either version 3 of the
    024 *          License, or (at your option) any later version. <br>
    025 * <br>
    026 *          This library is distributed in the hope that it will be useful, but
    027 *          WITHOUT ANY WARRANTY; without even the implied warranty of
    028 *          MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
    029 *          Lesser General Public License for more details. <br>
    030 * <br>
    031 *          You should have received a copy of the GNU Lesser General Public
    032 *          License along with this library; if not see
    033 *          <a href='http://www.gnu.org/licenses/'>http://www.gnu.org/licenses/</a>.
    034 */
    035public class Machine extends Constraint<Operation, Location> {
    036    private int iMachineNumber = -1;
    037
    038    /**
    039     * Constructor
    040     *
    041     * @param machineNumber
    042     *            machine number
    043     */
    044    public Machine(int machineNumber) {
    045        super();
    046        iMachineNumber = machineNumber;
    047    }
    048
    049    /** Get machine number
    050     * @return machine number
    051     **/
    052    public int getMachineNumber() {
    053        return iMachineNumber;
    054    }
    055
    056    /**
    057     * Adds conflicting operations into the set of conflicts.
    058     */
    059    @Override
    060    public void computeConflicts(Assignment<Operation, Location> assignment, Location location, Set<Location> conflicts) {
    061        for (Operation o : assignedVariables(assignment)) {
    062            if (o.getOperationNumber() == location.variable().getOperationNumber() && o.getJobNumber() == location.variable().getJobNumber())
    063                continue;
    064            Location conf = assignment.getValue(o);
    065            if (conf.overlap(location))
    066                conflicts.add(conf);
    067        }
    068    }
    069
    070    /**
    071     * True if there is an operation from the machine which violates with the
    072     * given assignment.
    073     */
    074    @Override
    075    public boolean inConflict(Assignment<Operation, Location> assignment, Location location) {
    076        for (Operation o : assignedVariables(assignment)) {
    077            if (o.getOperationNumber() == location.variable().getOperationNumber()
    078                    && o.getJobNumber() == location.variable().getJobNumber())
    079                continue;
    080            if (assignment.getValue(o).overlap(location))
    081                return true;
    082        }
    083        return false;
    084    }
    085
    086    /**
    087     * True if the two assignments (placement of opeartions of the machine in
    088     * time) violates each other.
    089     */
    090    @Override
    091    public boolean isConsistent(Location value1, Location value2) {
    092        return !value1.overlap(value2);
    093    }
    094
    095    /** string representation -- for debuging and printing purposes */
    096    @Override
    097    public String toString() {
    098        return getName();
    099    }
    100
    101    /**
    102     * Name of the machine (e.g. M10 where 10 is the machine number)
    103     */
    104    @Override
    105    public String getName() {
    106        return "M" + iMachineNumber;
    107    }
    108}