001    /*
002     * SonarQube, open source software quality management tool.
003     * Copyright (C) 2008-2014 SonarSource
004     * mailto:contact AT sonarsource DOT com
005     *
006     * SonarQube 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     * SonarQube 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 License
017     * along with this program; if not, write to the Free Software Foundation,
018     * Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
019     */
020    package org.sonar.api.utils.dag;
021    
022    import org.sonar.api.utils.SonarException;
023    
024    import java.util.ArrayList;
025    import java.util.List;
026    
027    /**
028     * @since 1.10
029     */
030    public class Node implements Comparable<Node> {
031    
032      private final Object object;
033      private int order = 0;
034      private boolean seen = false;
035      private final List<Node> dependencies = new ArrayList<Node>();
036    
037      public Node(final Object object) {
038        if (object == null) {
039          throw new SonarException("object can not be null");
040        }
041        this.object = object;
042      }
043    
044      public void reset() {
045        order = 0;
046        seen = false;
047      }
048    
049      public Object getObject() {
050        return object;
051      }
052    
053      public void addDependency(Node v) {
054        if (!equals(v) && !dependencies.contains(v)) {
055          dependencies.add(v);
056        }
057      }
058    
059      public void resolveOrder() {
060        resolveOrder(toString());
061      }
062    
063      private int resolveOrder(String path) {
064        seen = true;
065        try {
066          int highOrder = -1;
067          for (Node dep : dependencies) {
068            if (dep.seen) {
069              throw new CyclicDependenciesException(path + " -> " + dep.toString());
070            }
071            highOrder = Math.max(highOrder, dep.resolveOrder(path + " -> " + dep.toString()));
072    
073          }
074    
075          order = highOrder + 1;
076          return order;
077    
078        } finally {
079          seen = false;
080        }
081      }
082    
083      public List<Node> getDependencies() {
084        return dependencies;
085      }
086    
087      public int compareTo(final Node other) {
088        int orderInd = 0;
089    
090        if (order < other.order) {
091          orderInd = -1;
092        } else if (order > other.order) {
093          orderInd = 1;
094        }
095    
096        return orderInd;
097      }
098    
099      @Override
100      public String toString() {
101        return object.toString();
102      }
103    
104      @Override
105      public boolean equals(Object o) {
106        if (this == o) {
107          return true;
108        }
109        if (!(o instanceof Node)) {
110          return false;
111        }
112        return object.equals(((Node) o).getObject());
113      }
114    
115      @Override
116      public int hashCode() {
117        return object.hashCode();
118      }
119    }
120