001package net.sf.cpsolver.ifs.example.jobshop;
002
003import java.util.Set;
004
005import net.sf.cpsolver.ifs.model.Constraint;
006
007/**
008 * Machine constraint. <br>
009 * <br>
010 * Each machine contians a given set of operations (variables). A machine
011 * constraint is satisfied, if all operations on it do not overlap in time.
012 * 
013 * @version IFS 1.2 (Iterative Forward Search)<br>
014 *          Copyright (C) 2006 - 2010 Tomáš Müller<br>
015 *          <a href="mailto:muller@unitime.org">muller@unitime.org</a><br>
016 *          <a href="http://muller.unitime.org">http://muller.unitime.org</a><br>
017 * <br>
018 *          This library is free software; you can redistribute it and/or modify
019 *          it under the terms of the GNU Lesser General Public License as
020 *          published by the Free Software Foundation; either version 3 of the
021 *          License, or (at your option) any later version. <br>
022 * <br>
023 *          This library is distributed in the hope that it will be useful, but
024 *          WITHOUT ANY WARRANTY; without even the implied warranty of
025 *          MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
026 *          Lesser General Public License for more details. <br>
027 * <br>
028 *          You should have received a copy of the GNU Lesser General Public
029 *          License along with this library; if not see
030 *          <a href='http://www.gnu.org/licenses/'>http://www.gnu.org/licenses/</a>.
031 */
032public class Machine extends Constraint<Operation, Location> {
033    private int iMachineNumber = -1;
034
035    /**
036     * Constructor
037     * 
038     * @param machineNumber
039     *            machine number
040     */
041    public Machine(int machineNumber) {
042        super();
043        iMachineNumber = machineNumber;
044    }
045
046    /** Get machine number */
047    public int getMachineNumber() {
048        return iMachineNumber;
049    }
050
051    /**
052     * Adds conflicting operations into the set of conflicts.
053     */
054    @Override
055    public void computeConflicts(Location location, Set<Location> conflicts) {
056        for (Operation o : assignedVariables()) {
057            if (o.getOperationNumber() == location.variable().getOperationNumber()
058                    && o.getJobNumber() == location.variable().getJobNumber())
059                continue;
060            if (o.getAssignment().overlap(location))
061                conflicts.add(o.getAssignment());
062        }
063    }
064
065    /**
066     * True if there is an operation from the machine which violates with the
067     * given assignment.
068     */
069    @Override
070    public boolean inConflict(Location location) {
071        for (Operation o : assignedVariables()) {
072            if (o.getOperationNumber() == location.variable().getOperationNumber()
073                    && o.getJobNumber() == location.variable().getJobNumber())
074                continue;
075            if (o.getAssignment().overlap(location))
076                return true;
077        }
078        return false;
079    }
080
081    /**
082     * True if the two assignments (placement of opeartions of the machine in
083     * time) violates each other.
084     */
085    @Override
086    public boolean isConsistent(Location value1, Location value2) {
087        return !value1.overlap(value2);
088    }
089
090    /** string representation -- for debuging and printing purposes */
091    @Override
092    public String toString() {
093        return getName();
094    }
095
096    /**
097     * Name of the machine (e.g. M10 where 10 is the machine number)
098     */
099    @Override
100    public String getName() {
101        return "M" + iMachineNumber;
102    }
103}