code: /**
   * This file is part of Eclipse Steady.
   *
   * Licensed under the Apache License, Version 2.0 (the "License");
   * you may not use this file except in compliance with the License.
   * You may obtain a copy of the License at
   *
   *     http://www.apache.org/licenses/LICENSE-2.0
   *
   * Unless required by applicable law or agreed to in writing, software
   * distributed under the License is distributed on an "AS IS" BASIS,
   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   * See the License for the specific language governing permissions and
   * limitations under the License.
   *
   * SPDX-License-Identifier: Apache-2.0
   * SPDX-FileCopyrightText: Copyright (c) 2018-2020 SAP SE or an SAP affiliate company and Eclipse Steady contributors
   */
  package org.eclipse.steady.cg;
  
  import java.util.ArrayList;
  import java.util.HashSet;
  import java.util.Iterator;
  import java.util.LinkedList;
  
  import org.apache.logging.log4j.Logger;
  import org.eclipse.steady.shared.json.model.ConstructId;
  
  import com.ibm.wala.util.graph.Graph;
  
  /**
   * <p>DepthFirstGetPaths class.</p>
   */
  public class DepthFirstGetPaths extends AbstractGetPaths {
  
    private static final Logger log = org.apache.logging.log4j.LogManager.getLogger();
  
    private long start_millis = System.currentTimeMillis(), end_millis = System.currentTimeMillis();
  
    /**
     * <p>Constructor for DepthFirstGetPaths.</p>
     *
     * @param _graph a {@link com.ibm.wala.util.graph.Graph} object.
     * @param _nodeid a {@link java.util.ArrayList} object.
     */
    public DepthFirstGetPaths(Graph<Integer> _graph, ArrayList<ConstructId> _nodeid) {
      super(_graph, _nodeid);
    }
  
    /** {@inheritDoc} */
    public HashSet<LinkedList<ConstructId>> getAllPaths(ConstructId _src, ConstructId _tgt) {
      this.start_millis = System.currentTimeMillis();
      HashSet<LinkedList<Integer>> paths = new HashSet<LinkedList<Integer>>();
      Integer currentNode = this.nodeId.indexOf(_src);
      LinkedList<Integer> visited = new LinkedList<Integer>();
      visited.add(currentNode);
      findAllPaths(visited, paths, currentNode, this.nodeId.indexOf(_tgt));
      HashSet<LinkedList<ConstructId>> result = new HashSet<LinkedList<ConstructId>>();
      for (LinkedList<Integer> p : paths) {
        LinkedList<ConstructId> newp = new LinkedList<ConstructId>();
        for (Integer i : p) newp.add(this.nodeId.get(i));
        result.add(newp);
      }
      return result;
    }
  
    private void findAllPaths(
        LinkedList<Integer> visited,
        HashSet<LinkedList<Integer>> paths,
        Integer currentNode,
        Integer _tgt) {
      if (currentNode.equals(_tgt)) {
        LinkedList<Integer> newpath = new LinkedList<Integer>();
        newpath.addAll(visited);
        paths.add(newpath);
        if ((!paths.isEmpty()) && paths.size() % 5 == 0) {
          this.end_millis = System.currentTimeMillis();
          DepthFirstGetPaths.log.info(
              "Found 5 more paths in [ " + (this.end_millis - this.start_millis) + " millisecs ]");
        }
        return;
      } else {
        int succnode = -1;
        Iterator<Integer> nodes = this.graph.getSuccNodes(currentNode);
        while (nodes.hasNext()) {
          succnode = nodes.next();
          if (visited.contains(succnode)) {
            continue;
          }
          LinkedList<Integer> temp = new LinkedList<Integer>();
          temp.addAll(visited);
          temp.add(succnode);
          findAllPaths(temp, paths, succnode, _tgt);
        }
      }
    }
  }
  