001    /*
002     * Sonar, open source software quality management tool.
003     * Copyright (C) 2008-2012 SonarSource
004     * mailto:contact AT sonarsource DOT com
005     *
006     * Sonar is free software; you can redistribute it and/or
007     * modify it under the terms of the GNU Lesser General Public
008     * License as published by the Free Software Foundation; either
009     * version 3 of the License, or (at your option) any later version.
010     *
011     * Sonar is distributed in the hope that it will be useful,
012     * but WITHOUT ANY WARRANTY; without even the implied warranty of
013     * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
014     * Lesser General Public License for more details.
015     *
016     * You should have received a copy of the GNU Lesser General Public
017     * License along with Sonar; if not, write to the Free Software
018     * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02
019     */
020    package org.sonar.graph;
021    
022    import java.util.Collection;
023    import java.util.HashSet;
024    import java.util.Set;
025    
026    public class IncrementalCyclesAndFESSolver<V> {
027    
028      private Set<Cycle> cycles = new HashSet<Cycle>();
029      private long searchCyclesCalls = 0;
030      private static final int DEFAULT_MAX_SEARCH_DEPTH_AT_FIRST = 3;
031      private static final int DEFAULT_MAX_CYCLES_TO_FOUND_BY_ITERATION = 100;
032      private MinimumFeedbackEdgeSetSolver solver;
033      private int iterations = 0;
034    
035      public IncrementalCyclesAndFESSolver(DirectedGraphAccessor<V, ? extends Edge> graph, Collection<V> vertices) {
036        this(graph, vertices, DEFAULT_MAX_SEARCH_DEPTH_AT_FIRST, DEFAULT_MAX_CYCLES_TO_FOUND_BY_ITERATION);
037      }
038    
039      public IncrementalCyclesAndFESSolver(DirectedGraphAccessor<V, ? extends Edge> graph, Collection<V> vertices, int maxSearchDepthAtFirst,
040          int maxCyclesToFoundByIteration) {
041    
042        iterations++;
043        CycleDetector<V> cycleDetector = new CycleDetector<V>(graph, vertices);
044        cycleDetector.detectCyclesWithMaxSearchDepth(maxSearchDepthAtFirst);
045        searchCyclesCalls += cycleDetector.getSearchCyclesCalls();
046        cycles.addAll(cycleDetector.getCycles());
047        solver = new MinimumFeedbackEdgeSetSolver(cycles);
048        Set<Edge> edgesToExclude = solver.getEdges();
049    
050        do {
051          iterations++;
052          cycleDetector = new CycleDetector<V>(graph, vertices, edgesToExclude);
053          cycleDetector.detectCyclesWithUpperLimit(maxCyclesToFoundByIteration);
054          searchCyclesCalls += cycleDetector.getSearchCyclesCalls();
055          cycles.addAll(cycleDetector.getCycles());
056          solver = new MinimumFeedbackEdgeSetSolver(cycles);
057          edgesToExclude = solver.getEdges();
058        } while (cycleDetector.getCycles().size() != 0);
059      }
060    
061      public int getWeightOfFeedbackEdgeSet() {
062        return solver.getWeightOfFeedbackEdgeSet();
063      }
064    
065      public int getNumberOfLoops() {
066        return solver.getNumberOfLoops();
067      }
068    
069      public Set<Edge> getFeedbackEdgeSet() {
070        return solver.getEdges();
071      }
072    
073      public Set<Cycle> getCycles() {
074        return cycles;
075      }
076    
077      public boolean isAcyclicGraph() {
078        return cycles.isEmpty();
079      }
080    
081      public long getSearchCyclesCalls() {
082        return searchCyclesCalls;
083      }
084    
085      public int getIterations() {
086        return iterations;
087      }
088    }