/*
* GeoTools - The Open Source Java GIS Toolkit
* http://geotools.org
*
* (C) 2002-2008, Open Source Geospatial Foundation (OSGeo)
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation;
* version 2.1 of the License.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*/
package org.geotools.graph.traverse.standard;
import java.util.Map;
import java.util.StringTokenizer;
import junit.framework.TestCase;
import org.geotools.graph.GraphTestUtil;
import org.geotools.graph.build.GraphBuilder;
import org.geotools.graph.build.basic.BasicGraphBuilder;
import org.geotools.graph.structure.Edge;
import org.geotools.graph.structure.GraphVisitor;
import org.geotools.graph.structure.Graphable;
import org.geotools.graph.structure.Node;
import org.geotools.graph.traverse.GraphTraversal;
import org.geotools.graph.traverse.basic.BasicGraphTraversal;
import org.geotools.graph.traverse.basic.CountingWalker;
public class DijkstraIteratorTest extends TestCase {
public GraphBuilder m_builder;
public DijkstraIteratorTest(String name) {
super(name);
}
protected void setUp() throws Exception {
super.setUp();
m_builder = createBuilder();
}
/**
* Create a graph with no bifurcations and start a full traversal from start
* node. <BR>
* <BR>
* Expected: 1. Every node should be visited in order.
* 2. Every node should have a cost associated with == id
* 3. Every node should havea parent with id node id + 1
*
*/
public void test_0() {
int nnodes = 100;
Node[] ends = GraphTestUtil.buildNoBifurcations(builder(), nnodes);
CountingWalker walker = new CountingWalker();
final DijkstraIterator iterator = createIterator();
iterator.setSource(ends[0]);
BasicGraphTraversal traversal = new BasicGraphTraversal(
builder().getGraph(), walker, iterator
);
traversal.init();
traversal.traverse();
GraphVisitor visitor = new GraphVisitor() {
public int visit(Graphable component) {
assertTrue(component.isVisited());
assertTrue(iterator.getCost(component) == (double)component.getID());
if (component.getID() == 0) assertNull(iterator.getParent(component));
else assertTrue(
iterator.getParent(component).getID() == component.getID() - 1
);
return 0;
}
};
builder().getGraph().visitNodes(visitor);
assertTrue(walker.getCount() == nnodes);
}
/**
* Create a graph with no bifurcations and start a traversal from start
* node, then suspend, and resume. <BR>
* <BR>
* Expected: After supsend:
* 1. Nodes from 0 to suspend node should be visted, others not.
*
* After resume:
* 1. Next node visited should have id suspend node id + 1
* 2. Every node should have a cost associated with it == id
* 3. Every node should have a parent with id node id + 1
*/
public void test_1() {
int nnodes = 100;
Node[] ends = GraphTestUtil.buildNoBifurcations(builder(), nnodes);
final int suspend = 50;
CountingWalker walker = new CountingWalker() {
int m_mode = 0;
public int visit(Graphable element, GraphTraversal traversal) {
super.visit(element, traversal);
if (m_mode == 0) {
if (element.getID() == suspend) {
m_mode++;
return(GraphTraversal.SUSPEND);
}
}
else if (m_mode == 1) {
assertTrue(element.getID() == suspend+1);
m_mode++;
}
return(GraphTraversal.CONTINUE);
}
};
final DijkstraIterator iterator = createIterator();
iterator.setSource(ends[0]);
BasicGraphTraversal traversal = new BasicGraphTraversal(
builder().getGraph(), walker, iterator
);
traversal.init();
traversal.traverse();
GraphVisitor visitor = new GraphVisitor() {
public int visit(Graphable component) {
if (component.getID() <= suspend) assertTrue(component.isVisited());
else assertTrue(!component.isVisited());
return 0;
}
};
builder().getGraph().visitNodes(visitor);
assertTrue(walker.getCount() == nnodes-suspend+1);
//resume
traversal.traverse();
visitor = new GraphVisitor() {
public int visit(Graphable component) {
assertTrue(component.isVisited());
assertTrue(iterator.getCost(component) == (double)component.getID());
if (component.getID() == 0) assertNull(iterator.getParent(component));
else assertTrue(
iterator.getParent(component).getID() == component.getID() - 1
);
return 0;
}
};
builder().getGraph().visitNodes(visitor);
assertTrue(walker.getCount() == nnodes);
}
/**
* Create a graph with no bifurcations and start a traversal from start
* node, then kill branch, and resume. <BR>
* <BR>
* Expected: After kill branch:
* 1. Traversal ends
* After resume:
* 2. No more nodes visited.
*/
public void test_2() {
int nnodes = 100;
Node[] ends = GraphTestUtil.buildNoBifurcations(builder(), nnodes);
final int kill = 50;
CountingWalker walker = new CountingWalker() {
int m_mode = 0;
public int visit(Graphable element, GraphTraversal traversal) {
super.visit(element, traversal);
if (m_mode == 0) {
if (element.getID() == kill) {
m_mode++;
return(GraphTraversal.KILL_BRANCH);
}
}
return(GraphTraversal.CONTINUE);
}
};
final DijkstraIterator iterator = createIterator();
iterator.setSource(ends[0]);
BasicGraphTraversal traversal = new BasicGraphTraversal(
builder().getGraph(), walker, iterator
);
traversal.init();
traversal.traverse();
GraphVisitor visitor = new GraphVisitor() {
public int visit(Graphable component) {
if (component.getID() <= kill) assertTrue(component.isVisited());
else assertTrue(!component.isVisited());
return 0;
}
};
builder().getGraph().visitNodes(visitor);
assertTrue(walker.getCount() == nnodes-kill+1);
//resume
traversal.traverse();
builder().getGraph().visitNodes(visitor);
assertTrue(walker.getCount() == nnodes-kill+1);
}
/**
* Create a balanced binary tree and do a normal traversal starting at root.
* <BR>
* <BR>
* Expected: 1. Every node should be visited.
* 2. The dijsktra parent of each node should be the same as
* the parent of the tree.
* 3. The cost of each node should be equal to its depth.
*/
public void test_3() {
int k = 4;
Object[] obj = GraphTestUtil.buildPerfectBinaryTree(builder(), k);
final Node root = (Node)obj[0];
CountingWalker walker = new CountingWalker();
final DijkstraIterator iterator = createIterator();
iterator.setSource((Node)obj[0]);
BasicGraphTraversal traversal = new BasicGraphTraversal(
builder().getGraph(), walker, iterator
);
traversal.init();
traversal.traverse();
GraphVisitor visitor = new GraphVisitor() {
public int visit(Graphable component) {
assertTrue(component.isVisited());
String id = component.getObject().toString();
StringTokenizer st = new StringTokenizer(id, ".");
assertTrue(iterator.getCost(component) == (double)st.countTokens()-1);
if (component != root) {
String parentid = id.substring(0, id.length()-2);
assertTrue(
iterator.getParent(component).getObject().toString().equals(parentid)
);
}
return 0;
}
};
builder().getGraph().visitNodes(visitor);
assertTrue(walker.getCount() == Math.pow(2,k+1)-1);
}
/**
* Create a balanced binary tree and do a normal traversal starting at root
* and then suspend at right right child of root, then resume
* <BR>
* <BR>
* Expected: After suspend:
* 1. Not every node should be visited
* After resume:
* 1. Every node should be visited.
*/
public void test_4() {
int k = 4;
Object[] obj = GraphTestUtil.buildPerfectBinaryTree(builder(), k);
Map id2node = (Map)obj[1];
final Node root = (Node)obj[0];
final Node lc = (Node)id2node.get(root.getObject().toString() + ".0");
final Node rc = (Node)id2node.get(root.getObject().toString() + ".1");
CountingWalker walker = new CountingWalker() {
private int m_mode = 0;
public int visit(Graphable element, GraphTraversal traversal) {
super.visit(element, traversal);
if (m_mode == 0) {
if (element == rc) {
m_mode++;
return(GraphTraversal.SUSPEND);
}
}
return(GraphTraversal.CONTINUE);
}
};
final DijkstraIterator iterator = createIterator();
iterator.setSource((Node)obj[0]);
BasicGraphTraversal traversal = new BasicGraphTraversal(
builder().getGraph(), walker, iterator
);
traversal.init();
traversal.traverse();
GraphVisitor visitor = new GraphVisitor() {
public int visit(Graphable component) {
if (component != root && component != lc && component != rc)
assertTrue(!component.isVisited());
return 0;
}
};
builder().getGraph().visitNodes(visitor);
//resume
traversal.traverse();
visitor = new GraphVisitor() {
public int visit(Graphable component) {
assertTrue(component.isVisited());
return(0);
}
};
builder().getGraph().visitNodes(visitor);
assertTrue(walker.getCount() == Math.pow(2,k+1)-1);
}
/**
* Create a balanced binary tree and do a normal traversal starting at root
* and then kill at right right child of root, then resume
* <BR>
* <BR>
* Expected: 1. Every node in left subtree should be visited
* 2. Every node in right substree (minus right child of root)
* should not be visited
*
*/
public void test_5() {
int k = 4;
Object[] obj = GraphTestUtil.buildPerfectBinaryTree(builder(), k);
Map id2node = (Map)obj[1];
final Node root = (Node)obj[0];
final Node lc = (Node)id2node.get(root.getObject().toString() + ".0");
final Node rc = (Node)id2node.get(root.getObject().toString() + ".1");
CountingWalker walker = new CountingWalker() {
private int m_mode = 0;
public int visit(Graphable element, GraphTraversal traversal) {
super.visit(element, traversal);
if (m_mode == 0) {
if (element == rc) {
m_mode++;
return(GraphTraversal.KILL_BRANCH);
}
}
return(GraphTraversal.CONTINUE);
}
};
final DijkstraIterator iterator = createIterator();
iterator.setSource((Node)obj[0]);
BasicGraphTraversal traversal = new BasicGraphTraversal(
builder().getGraph(), walker, iterator
);
traversal.init();
traversal.traverse();
GraphVisitor visitor = new GraphVisitor() {
public int visit(Graphable component) {
if (component == root || component == lc || component == rc)
assertTrue(component.isVisited());
else {
String id = component.getObject().toString();
if (id.startsWith("0.1.")) assertTrue(!component.isVisited());
else assertTrue(component.isVisited());
}
return 0;
}
};
builder().getGraph().visitNodes(visitor);
assertTrue(walker.getCount() == Math.pow(2,k)+1);
}
/**
* Create a circular graph and perform a full traversal. <BR>
* <BR>
* Expected : 1. For nodes with id < (total # of nodes) / 2:
* a. parent should be node with id - 1
* b. cost == id
* 2. For nodes with id > (total # of nodes) / 2;
* a. parent should be node with id + 1
* b. cost == total # of nodes - id
*
*/
public void test_6() {
int nnodes = 100;
Node[] ends = GraphTestUtil.buildCircular(builder(), nnodes);
CountingWalker walker = new CountingWalker();
final DijkstraIterator iterator = createIterator();
iterator.setSource(ends[0]);
BasicGraphTraversal traversal = new BasicGraphTraversal(
builder().getGraph(), walker, iterator
);
traversal.init();
traversal.traverse();
GraphVisitor visitor = new GraphVisitor() {
public int visit(Graphable component) {
Graphable parent = iterator.getParent(component);
if (component.getID() < 50 && component.getID() > 0) {
assertTrue(iterator.getCost(component) == (double)component.getID());
assertTrue(parent.getID() == component.getID() - 1);
}
else if (component.getID() > 50 && component.getID() < 99) {
assertTrue(
iterator.getCost(component) == (double)100 - component.getID()
);
assertTrue(parent.getID() == component.getID() + 1);
}
else if (component.getID() == 0) {
assertTrue(parent == null);
assertTrue(iterator.getCost(component) == 0d);
}
else if (component.getID() == 99) {
assertTrue(parent.getID() == 0);
assertTrue(iterator.getCost(component) == 1d);
}
return(0);
}
};
builder().getGraph().visitNodes(visitor);
assertTrue(walker.getCount() == nnodes);
}
protected DijkstraIterator createIterator() {
return(
new DijkstraIterator(
new DijkstraIterator.EdgeWeighter() {
public double getWeight(Edge e) {
return(1);
}
}
)
);
}
protected GraphBuilder createBuilder() {
return(new BasicGraphBuilder());
}
protected GraphBuilder builder() {
return(m_builder);
}
}