| /* |
| * Copyright 2014-present Open Networking Laboratory |
| * |
| * 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. |
| */ |
| package org.onlab.graph; |
| |
| import org.junit.Test; |
| |
| import java.util.HashSet; |
| import java.util.Set; |
| |
| import static com.google.common.collect.ImmutableSet.of; |
| import static org.junit.Assert.assertEquals; |
| import static org.onlab.graph.GraphPathSearch.ALL_PATHS; |
| |
| /** |
| * Test of the Bellman-Ford algorithm. |
| */ |
| public class BellmanFordGraphSearchTest extends BreadthFirstSearchTest { |
| |
| @Override |
| protected AbstractGraphPathSearch<TestVertex, TestEdge> graphSearch() { |
| return new BellmanFordGraphSearch<>(); |
| } |
| |
| @Test |
| @Override |
| public void defaultGraphTest() { |
| executeDefaultTest(7, 5, new TestDoubleWeight(5.0)); |
| } |
| |
| @Test |
| public void defaultHopCountWeight() { |
| weigher = null; |
| executeDefaultTest(10, 3, new ScalarWeight(3.0)); |
| } |
| |
| @Test |
| public void searchGraphWithNegativeCycles() { |
| Set<TestVertex> vertexes = new HashSet<>(vertexes()); |
| vertexes.add(Z); |
| |
| Set<TestEdge> edges = new HashSet<>(edges()); |
| edges.add(new TestEdge(G, Z, new TestDoubleWeight(1.0))); |
| edges.add(new TestEdge(Z, G, new TestDoubleWeight(-2.0))); |
| |
| graph = new AdjacencyListsGraph<>(vertexes, edges); |
| |
| GraphPathSearch<TestVertex, TestEdge> search = graphSearch(); |
| Set<Path<TestVertex, TestEdge>> paths = search.search(graph, A, H, weigher, ALL_PATHS).paths(); |
| assertEquals("incorrect paths count", 1, paths.size()); |
| |
| Path p = paths.iterator().next(); |
| assertEquals("incorrect src", A, p.src()); |
| assertEquals("incorrect dst", H, p.dst()); |
| assertEquals("incorrect path length", 5, p.edges().size()); |
| assertEquals("incorrect path cost", new TestDoubleWeight(5), p.cost()); |
| |
| paths = search.search(graph, A, G, weigher, ALL_PATHS).paths(); |
| assertEquals("incorrect paths count", 0, paths.size()); |
| |
| paths = search.search(graph, A, null, weigher, ALL_PATHS).paths(); |
| printPaths(paths); |
| assertEquals("incorrect paths count", 6, paths.size()); |
| } |
| @Test |
| public void testNegativeEdge() { |
| graph = new AdjacencyListsGraph<>(of(A, B, C, D), |
| of(new TestEdge(A, B, W3), |
| new TestEdge(A, C, W4), |
| new TestEdge(C, B, NW2), |
| new TestEdge(B, C, W2), |
| new TestEdge(A, D, W5), |
| new TestEdge(D, B, new TestDoubleWeight(-3)))); |
| GraphPathSearch<TestVertex, TestEdge> gs = graphSearch(); |
| Set<Path<TestVertex, TestEdge>> paths = gs.search(graph, A, B, weigher, 1).paths(); |
| printPaths(paths); |
| assertEquals("incorrect path count", 1, paths.size()); |
| assertEquals("incoreect path cost", new TestDoubleWeight(2), paths.iterator().next().cost()); |
| |
| executeSearch(graphSearch(), graph, A, B, weigher, 2, W2); |
| } |
| |
| @Test |
| public void multipleNegatives() { |
| graph = new AdjacencyListsGraph<>(of(A, B, C, D, E), |
| of(new TestEdge(A, B, W1), |
| new TestEdge(B, C, W1), |
| new TestEdge(C, D, W1), |
| new TestEdge(D, E, W1), |
| new TestEdge(A, B, new TestDoubleWeight(-4)), |
| new TestEdge(A, C, new TestDoubleWeight(-3)), |
| new TestEdge(A, D, NW1), |
| new TestEdge(D, C, NW1))); |
| executeSearch(graphSearch(), graph, A, E, weigher, 2, NW1); |
| executeSinglePathSearch(graphSearch(), graph, A, E, weigher, 1, NW1); |
| executeSearch(graphSearch(), graph, B, C, weigher, 1, W1); |
| } |
| |
| @Test |
| public void manualWeights() { |
| graph = new AdjacencyListsGraph<>(of(A, B, C), |
| of(new TestEdge(A, B, new TestDoubleWeight(-3.3)), |
| new TestEdge(B, C, new TestDoubleWeight(1.3)), |
| new TestEdge(A, C, new TestDoubleWeight(-1.9)), |
| new TestEdge(B, C, new TestDoubleWeight(1.5)))); |
| executeSearch(graphSearch(), graph, A, C, weigher, 1, new TestDoubleWeight(-2.0)); |
| } |
| |
| } |