src/main/org/testng/internal/Graph.java - platform/external/testng - Git at Google

 package org.testng.internal;

 import java.util.ArrayList;
 import java.util.Collection;
 import java.util.HashMap;
 import java.util.List;
 import java.util.Map;
 import java.util.Set;

 import org.testng.TestNGException;
 /**
  * Simple graph class to implement topological sort (used to sort methods based on what groups
  * they depend on).
  *
  * @author Cedric Beust, Aug 19, 2004
  */
 public class Graph<T extends Object> {
   private static boolean m_verbose = false;
   private Map<T, Node<T>> m_nodes = new HashMap<T, Node<T>>();
   private List<T> m_strictlySortedNodes = null;

   //  A map of nodes that are not the predecessors of any node
   // (not needed for the algorithm but convenient to calculate
   // the parallel/sequential lists in TestNG).
   private Map<T, Node<T>> m_independentNodes = null;

   public void addNode(T tm) {
     ppp("ADDING NODE " + tm + " " + tm.hashCode());
     m_nodes.put(tm, new Node<T>(tm));
     // Initially, all the nodes are put in the independent list as well
   }

   /*private boolean hasBeenSorted() {
     return null != m_strictlySortedNodes;
   }*/

   public boolean isIndependent(T object) {
     return m_independentNodes.containsKey(object);
   }

   private Node<T> findNode(T object) {
     return m_nodes.get(object);
   }

   public void addPredecessor(T tm, T predecessor) {
     Node<T> node = findNode(tm);
     if (null == node) {
       throw new TestNGException("Non-existing node: " + tm);
     }
     else {
       node.addPredecessor(predecessor);
       // Remove these two nodes from the independent list
       if (null == m_independentNodes) {
         m_independentNodes = new HashMap<T, Node<T>>();
         for (T k : m_nodes.keySet()) {
           m_independentNodes.put(k, m_nodes.get(k));
         }
       }
       m_independentNodes.remove(predecessor);
       m_independentNodes.remove(tm);
       ppp("  REMOVED " + predecessor + " FROM INDEPENDENT OBJECTS");
     }
   }

   private Collection<Node<T>> getNodes() {
     return m_nodes.values();
   }

   /**
    * @return All the nodes that don't have any order with each other.
    */
   public Set<T> getIndependentNodes() {
     return m_independentNodes.keySet();
   }

   /**
    * @return All the nodes that have an order with each other, sorted
    * in one of the valid sorts.
    */
   public List<T> getStrictlySortedNodes() {
     return m_strictlySortedNodes;
   }

   public void topologicalSort() {
     ppp("================ SORTING");
     m_strictlySortedNodes = new ArrayList<T>();
     if (null == m_independentNodes) {
       m_independentNodes = new HashMap<T, Node<T>>();
     }

     //
     // Clone the list of nodes but only keep those that are
     // not independent.
     //
     List<Node<T>> nodes2 = new ArrayList<Node<T>>();
     for (Node<T> n : getNodes()) {
       if (! isIndependent((T) n.getObject())) {
         ppp("ADDING FOR SORT: " + n.getObject());
         nodes2.add(n.clone());
       }
       else {
         ppp("SKIPPING INDEPENDENT NODE " + n);
       }
     }

     //
     // Sort
     //
     while (! nodes2.isEmpty()) {

       //
       // Find all the nodes that don't have any predecessors, add
       // them to the result and mark them for removal
       //
       Node<T> node = findNodeWithNoPredecessors(nodes2);
       if (null == node) {
         throw new TestNGException("Cyclic graph of methods");
       }
       else {
         m_strictlySortedNodes.add((T) node.getObject());
         removeFromNodes(nodes2, node);
       }
     }

     ppp("=============== DONE SORTING");
     if (m_verbose) {
       dumpSortedNodes();
     }
   }

   private void dumpSortedNodes() {
     System.out.println("====== SORTED NODES");
     for (T n : m_strictlySortedNodes) {
       System.out.println("              " + n);
     }
     System.out.println("====== END SORTED NODES");
   }

   private void dumpGraph() {
     System.out.println("====== GRAPH");
     for (Node<T> n : m_nodes.values()) {
       System.out.println("  " + n);
     }
   }

   /**
    * Remove a node from a list of nodes and update the list of predecessors
    * for all the remaining nodes.
    */
   private void removeFromNodes(List<Node<T>> nodes, Node<T> node) {
     nodes.remove(node);
     for (Node<T> n : nodes) {
       n.removePredecessor(node.getObject());
     }
   }

   private static void ppp(String s) {
     if (m_verbose) {
       System.out.println("[Graph] " + s);
     }
   }

   private Node<T> findNodeWithNoPredecessors(List<Node<T>> nodes) {
     for (Node<T> n : nodes) {
       if (! n.hasPredecessors()) {
         return n;
       }
     }

     return null;
   }

   /**
    * @param o
    * @return A list of all the predecessors for o
    */
   public List<T> findPredecessors(T o) {
     List<T> result = new ArrayList<T>();
     // Locate the node
     Node<T> node = findNode(o);

     if (null == node) {
       throw new AssertionError("No such node: " + o);
     }
     else {
       List<Node<T>> nodesToWalk = new ArrayList<Node<T>>();

       // Found the nodes, now find all its predecessors
       for (Node<T> n : getNodes()) {
         T obj = n.getObject();
         if (node.hasPredecessor(obj)) {
           ppp("FOUND PREDECESSOR " + n);
           if (! result.contains(obj)) {
             result.add(0, obj);
             nodesToWalk.add(n);
           }
         }
       }

       // Add all the predecessors of the nodes we just found
       for (Node<T> n : nodesToWalk) {
         List<T> r = findPredecessors(n.getObject());
         for (T obj : r) {
           if (! result.contains(obj)) {
             result.add(0, obj);
           }
         }
       }
     }

     return result;
   }

   @Override
   public String toString() {
     StringBuffer result = new StringBuffer("[Graph ");
     for (T node : m_nodes.keySet()) {
       result.append(findNode(node)).append(" ");
     }
     result.append("]");

     return result.toString();
   }


   /////
   // class Node
   //
   static class Node<T> {
     private T m_object = null;
     private Map<T, T> m_predecessors = new HashMap<T, T>();

     public Node(T tm) {
       m_object = tm;
     }

     @Override
     public Node<T> clone() {
       Node<T> result = new Node<T>(m_object);
       for (T pred : m_predecessors.values()) {
         result.addPredecessor(pred);
       }
       return result;
     }

     public T getObject() {
       return m_object;
     }

     public Map<T, T> getPredecessors() {
       return m_predecessors;
     }

     /**
      *
      * @return true if this predecessor was found and removed
      */
     public boolean removePredecessor(T o) {
       boolean result = false;

 //      dump();
       T pred = m_predecessors.get(o);
       if (null != pred) {
         result = null != m_predecessors.remove(o);
         if (result) {
           ppp("  REMOVED PRED " + o + " FROM NODE " + m_object);
         }
         else {
           ppp("  FAILED TO REMOVE PRED " + o + " FROM NODE " + m_object);
         }
       }

       return result;
     }

     private void dump() {
       ppp(toString());
     }

     @Override
     public String toString() {
       StringBuffer sb = new StringBuffer("[Node:" + m_object);
       sb.append("  pred:");
       for (T o : m_predecessors.values()) {
         sb.append(" " + o.toString());
       }
       sb.append("]");
       String result = sb.toString();
       return result;
     }

     public void addPredecessor(T tm) {
       ppp("  ADDING PREDECESSOR FOR " + m_object + " ==> " + tm);
       m_predecessors.put(tm, tm);
     }

     public boolean hasPredecessors() {
       return m_predecessors.size() > 0;
     }

     public boolean hasPredecessor(T m) {
       return m_predecessors.containsKey(m);
     }
   }

   //
   // class Node
   /////

   public static void main(String[] argv) {
     Graph<String> g = new Graph<String>();
     g.addNode("3");
     g.addNode("1");
     g.addNode("2.2");
     g.addNode("independent");
     g.addNode("2.1");
     g.addNode("2");

     // 1 ->  2.1, 2.2, 2.3 --> 3
     g.addPredecessor("3", "2");
     g.addPredecessor("3", "2.1");
     g.addPredecessor("3", "2.2");
     g.addPredecessor("2", "1");
     g.addPredecessor("2.1", "1");
     g.addPredecessor("2.2", "1");

     g.topologicalSort();

     List<String> l = g.getStrictlySortedNodes();
     for (String s : l) {
       System.out.println("  " + s);
     }
     int i = 0;
     assert "1".equals(l.get(i));
     i++;
     assert "2".equals(l.get(i)) || "2.1".equals(l.get(i)) || "2.2".equals(l.get(i));
     i++;
     assert "2".equals(l.get(i)) || "2.1".equals(l.get(i)) || "2.2".equals(l.get(i));
     i++;
     assert "2".equals(l.get(i)) || "2.1".equals(l.get(i)) || "2.2".equals(l.get(i));
     i++;
     assert "3".equals(l.get(i));

     assert 1 == g.getIndependentNodes().size();

     //
     // Test findPredecessors
     //
     ppp("GRAPH:" + g);
     {
       List<String> predecessors = g.findPredecessors("2");
       assert predecessors.size() == 1;
       assert predecessors.get(0).equals("1");
     }

     {
       List<String> predecessors = g.findPredecessors("3");
       assert predecessors.size() == 4;
       assert predecessors.get(0).equals("1");
       assert predecessors.get(1).equals("2.1") ||
         predecessors.get(2).equals("2.2") ||
         predecessors.get(2).equals("2");
       assert predecessors.get(2).equals("2.1") ||
       predecessors.get(2).equals("2.2") ||
       predecessors.get(2).equals("2");
       assert predecessors.get(3).equals("2.1") ||
       predecessors.get(2).equals("2.2") ||
       predecessors.get(2).equals("2");
     }

     ppp("TESTS PASSED");
   }

 }
	package org.testng.internal;

	import java.util.ArrayList;
	import java.util.Collection;
	import java.util.HashMap;
	import java.util.List;
	import java.util.Map;
	import java.util.Set;

	import org.testng.TestNGException;
	/**
	* Simple graph class to implement topological sort (used to sort methods based on what groups
	* they depend on).
	*
	* @author Cedric Beust, Aug 19, 2004
	*/
	public class Graph<T extends Object> {
	private static boolean m_verbose = false;
	private Map<T, Node<T>> m_nodes = new HashMap<T, Node<T>>();
	private List<T> m_strictlySortedNodes = null;

	// A map of nodes that are not the predecessors of any node
	// (not needed for the algorithm but convenient to calculate
	// the parallel/sequential lists in TestNG).
	private Map<T, Node<T>> m_independentNodes = null;

	public void addNode(T tm) {
	ppp("ADDING NODE " + tm + " " + tm.hashCode());
	m_nodes.put(tm, new Node<T>(tm));
	// Initially, all the nodes are put in the independent list as well
	}

	/*private boolean hasBeenSorted() {
	return null != m_strictlySortedNodes;
	}*/

	public boolean isIndependent(T object) {
	return m_independentNodes.containsKey(object);
	}

	private Node<T> findNode(T object) {
	return m_nodes.get(object);
	}

	public void addPredecessor(T tm, T predecessor) {
	Node<T> node = findNode(tm);
	if (null == node) {
	throw new TestNGException("Non-existing node: " + tm);
	}
	else {
	node.addPredecessor(predecessor);
	// Remove these two nodes from the independent list
	if (null == m_independentNodes) {
	m_independentNodes = new HashMap<T, Node<T>>();
	for (T k : m_nodes.keySet()) {
	m_independentNodes.put(k, m_nodes.get(k));
	}
	}
	m_independentNodes.remove(predecessor);
	m_independentNodes.remove(tm);
	ppp(" REMOVED " + predecessor + " FROM INDEPENDENT OBJECTS");
	}
	}

	private Collection<Node<T>> getNodes() {
	return m_nodes.values();
	}

	/**
	* @return All the nodes that don't have any order with each other.
	*/
	public Set<T> getIndependentNodes() {
	return m_independentNodes.keySet();
	}

	/**
	* @return All the nodes that have an order with each other, sorted
	* in one of the valid sorts.
	*/
	public List<T> getStrictlySortedNodes() {
	return m_strictlySortedNodes;
	}

	public void topologicalSort() {
	ppp("================ SORTING");
	m_strictlySortedNodes = new ArrayList<T>();
	if (null == m_independentNodes) {
	m_independentNodes = new HashMap<T, Node<T>>();
	}

	//
	// Clone the list of nodes but only keep those that are
	// not independent.
	//
	List<Node<T>> nodes2 = new ArrayList<Node<T>>();
	for (Node<T> n : getNodes()) {
	if (! isIndependent((T) n.getObject())) {
	ppp("ADDING FOR SORT: " + n.getObject());
	nodes2.add(n.clone());
	}
	else {
	ppp("SKIPPING INDEPENDENT NODE " + n);
	}
	}

	//
	// Sort
	//
	while (! nodes2.isEmpty()) {

	//
	// Find all the nodes that don't have any predecessors, add
	// them to the result and mark them for removal
	//
	Node<T> node = findNodeWithNoPredecessors(nodes2);
	if (null == node) {
	throw new TestNGException("Cyclic graph of methods");
	}
	else {
	m_strictlySortedNodes.add((T) node.getObject());
	removeFromNodes(nodes2, node);
	}
	}

	ppp("=============== DONE SORTING");
	if (m_verbose) {
	dumpSortedNodes();
	}
	}

	private void dumpSortedNodes() {
	System.out.println("====== SORTED NODES");
	for (T n : m_strictlySortedNodes) {
	System.out.println(" " + n);
	}
	System.out.println("====== END SORTED NODES");
	}

	private void dumpGraph() {
	System.out.println("====== GRAPH");
	for (Node<T> n : m_nodes.values()) {
	System.out.println(" " + n);
	}
	}

	/**
	* Remove a node from a list of nodes and update the list of predecessors
	* for all the remaining nodes.
	*/
	private void removeFromNodes(List<Node<T>> nodes, Node<T> node) {
	nodes.remove(node);
	for (Node<T> n : nodes) {
	n.removePredecessor(node.getObject());
	}
	}

	private static void ppp(String s) {
	if (m_verbose) {
	System.out.println("[Graph] " + s);
	}
	}

	private Node<T> findNodeWithNoPredecessors(List<Node<T>> nodes) {
	for (Node<T> n : nodes) {
	if (! n.hasPredecessors()) {
	return n;
	}
	}

	return null;
	}

	/**
	* @param o
	* @return A list of all the predecessors for o
	*/
	public List<T> findPredecessors(T o) {
	List<T> result = new ArrayList<T>();
	// Locate the node
	Node<T> node = findNode(o);

	if (null == node) {
	throw new AssertionError("No such node: " + o);
	}
	else {
	List<Node<T>> nodesToWalk = new ArrayList<Node<T>>();

	// Found the nodes, now find all its predecessors
	for (Node<T> n : getNodes()) {
	T obj = n.getObject();
	if (node.hasPredecessor(obj)) {
	ppp("FOUND PREDECESSOR " + n);
	if (! result.contains(obj)) {
	result.add(0, obj);
	nodesToWalk.add(n);
	}
	}
	}

	// Add all the predecessors of the nodes we just found
	for (Node<T> n : nodesToWalk) {
	List<T> r = findPredecessors(n.getObject());
	for (T obj : r) {
	if (! result.contains(obj)) {
	result.add(0, obj);
	}
	}
	}
	}

	return result;
	}

	@Override
	public String toString() {
	StringBuffer result = new StringBuffer("[Graph ");
	for (T node : m_nodes.keySet()) {
	result.append(findNode(node)).append(" ");
	}
	result.append("]");

	return result.toString();
	}


	/////
	// class Node
	//
	static class Node<T> {
	private T m_object = null;
	private Map<T, T> m_predecessors = new HashMap<T, T>();

	public Node(T tm) {
	m_object = tm;
	}

	@Override
	public Node<T> clone() {
	Node<T> result = new Node<T>(m_object);
	for (T pred : m_predecessors.values()) {
	result.addPredecessor(pred);
	}
	return result;
	}

	public T getObject() {
	return m_object;
	}

	public Map<T, T> getPredecessors() {
	return m_predecessors;
	}

	/**
	*
	* @return true if this predecessor was found and removed
	*/
	public boolean removePredecessor(T o) {
	boolean result = false;

	// dump();
	T pred = m_predecessors.get(o);
	if (null != pred) {
	result = null != m_predecessors.remove(o);
	if (result) {
	ppp(" REMOVED PRED " + o + " FROM NODE " + m_object);
	}
	else {
	ppp(" FAILED TO REMOVE PRED " + o + " FROM NODE " + m_object);
	}
	}

	return result;
	}

	private void dump() {
	ppp(toString());
	}

	@Override
	public String toString() {
	StringBuffer sb = new StringBuffer("[Node:" + m_object);
	sb.append(" pred:");
	for (T o : m_predecessors.values()) {
	sb.append(" " + o.toString());
	}
	sb.append("]");
	String result = sb.toString();
	return result;
	}

	public void addPredecessor(T tm) {
	ppp(" ADDING PREDECESSOR FOR " + m_object + " ==> " + tm);
	m_predecessors.put(tm, tm);
	}

	public boolean hasPredecessors() {
	return m_predecessors.size() > 0;
	}

	public boolean hasPredecessor(T m) {
	return m_predecessors.containsKey(m);
	}
	}

	//
	// class Node
	/////

	public static void main(String[] argv) {
	Graph<String> g = new Graph<String>();
	g.addNode("3");
	g.addNode("1");
	g.addNode("2.2");
	g.addNode("independent");
	g.addNode("2.1");
	g.addNode("2");

	// 1 -> 2.1, 2.2, 2.3 --> 3
	g.addPredecessor("3", "2");
	g.addPredecessor("3", "2.1");
	g.addPredecessor("3", "2.2");
	g.addPredecessor("2", "1");
	g.addPredecessor("2.1", "1");
	g.addPredecessor("2.2", "1");

	g.topologicalSort();

	List<String> l = g.getStrictlySortedNodes();
	for (String s : l) {
	System.out.println(" " + s);
	}
	int i = 0;
	assert "1".equals(l.get(i));
	i++;
	assert "2".equals(l.get(i)) \|\| "2.1".equals(l.get(i)) \|\| "2.2".equals(l.get(i));
	i++;
	assert "2".equals(l.get(i)) \|\| "2.1".equals(l.get(i)) \|\| "2.2".equals(l.get(i));
	i++;
	assert "2".equals(l.get(i)) \|\| "2.1".equals(l.get(i)) \|\| "2.2".equals(l.get(i));
	i++;
	assert "3".equals(l.get(i));

	assert 1 == g.getIndependentNodes().size();

	//
	// Test findPredecessors
	//
	ppp("GRAPH:" + g);
	{
	List<String> predecessors = g.findPredecessors("2");
	assert predecessors.size() == 1;
	assert predecessors.get(0).equals("1");
	}

	{
	List<String> predecessors = g.findPredecessors("3");
	assert predecessors.size() == 4;
	assert predecessors.get(0).equals("1");
	assert predecessors.get(1).equals("2.1") \|\|
	predecessors.get(2).equals("2.2") \|\|
	predecessors.get(2).equals("2");
	assert predecessors.get(2).equals("2.1") \|\|
	predecessors.get(2).equals("2.2") \|\|
	predecessors.get(2).equals("2");
	assert predecessors.get(3).equals("2.1") \|\|
	predecessors.get(2).equals("2.2") \|\|
	predecessors.get(2).equals("2");
	}

	ppp("TESTS PASSED");
	}

	}