001package org.cpsolver.ifs.assignment.context; 002 003import java.util.HashMap; 004import java.util.Map; 005 006import org.cpsolver.ifs.assignment.Assignment; 007import org.cpsolver.ifs.model.Value; 008import org.cpsolver.ifs.model.Variable; 009 010 011/** 012 * A simple assignment context holder implementation using {@link HashMap} to store all the assignment contexts. 013 * {@link AssignmentContextReference#getIndex()} are used to index the map. 014 * 015 * @see AssignmentContext 016 * @see AssignmentContextReference 017 * 018 * @version IFS 1.3 (Iterative Forward Search)<br> 019 * Copyright (C) 2014 Tomáš Müller<br> 020 * <a href="mailto:muller@unitime.org">muller@unitime.org</a><br> 021 * <a href="http://muller.unitime.org">http://muller.unitime.org</a><br> 022 * <br> 023 * This library is free software; you can redistribute it and/or modify 024 * it under the terms of the GNU Lesser General Public License as 025 * published by the Free Software Foundation; either version 3 of the 026 * License, or (at your option) any later version. <br> 027 * <br> 028 * This library is distributed in the hope that it will be useful, but 029 * WITHOUT ANY WARRANTY; without even the implied warranty of 030 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 031 * Lesser General Public License for more details. <br> 032 * <br> 033 * You should have received a copy of the GNU Lesser General Public 034 * License along with this library; if not see <a href='http://www.gnu.org/licenses'>http://www.gnu.org/licenses</a>. 035 * @param <V> Variable 036 * @param <T> Value 037 **/ 038public class AssignmentContextHolderMap<V extends Variable<V, T>, T extends Value<V, T>> implements AssignmentContextHolder<V, T> { 039 protected Map<Integer,AssignmentContext> iContexts = new HashMap<Integer, AssignmentContext>(); 040 041 public AssignmentContextHolderMap() { 042 } 043 044 @Override 045 @SuppressWarnings("unchecked") 046 public <U extends AssignmentContext> U getAssignmentContext(Assignment<V, T> assignment, AssignmentContextReference<V, T, U> reference) { 047 U context = (U) iContexts.get(reference.getIndex()); 048 if (context != null) return context; 049 050 context = reference.getParent().createAssignmentContext(assignment); 051 iContexts.put(reference.getIndex(), context); 052 return context; 053 } 054 055 @Override 056 public <C extends AssignmentContext> void clearContext(AssignmentContextReference<V, T, C> reference) { 057 iContexts.remove(reference.getIndex()); 058 } 059 060}