Java tutorial
/** * Licensed to the Apache Software Foundation (ASF) under one or more * contributor license agreements. See the NOTICE file distributed with * this work for additional information regarding copyright ownership. * The ASF licenses this file to You 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.apache.mahout.graph.common; import java.io.File; import java.util.Arrays; import java.util.Set; import com.google.common.collect.Sets; import com.google.common.io.Closeables; import org.apache.hadoop.conf.Configuration; import org.apache.hadoop.fs.FileSystem; import org.apache.hadoop.fs.Path; import org.apache.hadoop.io.NullWritable; import org.apache.hadoop.io.SequenceFile; import org.apache.hadoop.mapreduce.Mapper; import org.apache.hadoop.mapreduce.Reducer; import org.apache.mahout.common.MahoutTestCase; import org.apache.mahout.common.Pair; import org.apache.mahout.common.iterator.sequencefile.SequenceFileIterable; import org.apache.mahout.graph.model.UndirectedEdge; import org.apache.mahout.graph.model.UndirectedEdgeWithDegrees; import org.apache.mahout.graph.model.Vertex; import org.apache.mahout.graph.model.VertexWithDegree; import org.easymock.EasyMock; import org.junit.Test; public class AugmentGraphWithDegreesJobTest extends MahoutTestCase { @Test public void testScatterEdges() throws Exception { Mapper.Context ctx = EasyMock.createMock(Mapper.Context.class); ctx.write(new Vertex(123), new Vertex(456)); ctx.write(new Vertex(456), new Vertex(123)); EasyMock.replay(ctx); new AugmentGraphWithDegreesJob.ScatterEdgesMapper() .map(new UndirectedEdge(new Vertex(123), new Vertex(456)), null, ctx); EasyMock.verify(ctx); } @Test public void testSumDegrees() throws Exception { Reducer.Context ctx = EasyMock.createMock(Reducer.Context.class); Vertex vertex = new Vertex(1); ctx.write(new UndirectedEdge(vertex, new Vertex(3)), new VertexWithDegree(vertex, 3)); ctx.write(new UndirectedEdge(vertex, new Vertex(5)), new VertexWithDegree(vertex, 3)); ctx.write(new UndirectedEdge(vertex, new Vertex(7)), new VertexWithDegree(vertex, 3)); EasyMock.replay(ctx); new AugmentGraphWithDegreesJob.SumDegreesReducer().reduce(vertex, Arrays.asList(new Vertex(3), new Vertex(5), new Vertex(7)), ctx); EasyMock.verify(ctx); } @Test public void testJoinDegrees() throws Exception { Reducer.Context ctx = EasyMock.createMock(Reducer.Context.class); Vertex first = new Vertex(1); Vertex second = new Vertex(3); ctx.write(new UndirectedEdgeWithDegrees(new VertexWithDegree(first, 1), new VertexWithDegree(second, 3)), NullWritable.get()); EasyMock.replay(ctx); new AugmentGraphWithDegreesJob.JoinDegreesReducer().reduce(new UndirectedEdge(first, second), Arrays.asList(new VertexWithDegree(first, 1), new VertexWithDegree(second, 3)), ctx); EasyMock.verify(ctx); } @Test public void toyIntegrationTest() throws Exception { File inputFile = getTestTempFile("edges.seq"); File outputDir = getTestTempDir("output"); outputDir.delete(); File tempDir = getTestTempDir("tmp"); Configuration conf = new Configuration(); FileSystem fs = FileSystem.get(conf); SequenceFile.Writer writer = new SequenceFile.Writer(fs, conf, new Path(inputFile.getAbsolutePath().toString()), UndirectedEdge.class, NullWritable.class); try { writer.append(new UndirectedEdge(0, 1), NullWritable.get()); writer.append(new UndirectedEdge(0, 2), NullWritable.get()); writer.append(new UndirectedEdge(0, 3), NullWritable.get()); writer.append(new UndirectedEdge(0, 4), NullWritable.get()); writer.append(new UndirectedEdge(0, 5), NullWritable.get()); writer.append(new UndirectedEdge(0, 6), NullWritable.get()); writer.append(new UndirectedEdge(0, 7), NullWritable.get()); writer.append(new UndirectedEdge(1, 2), NullWritable.get()); writer.append(new UndirectedEdge(1, 3), NullWritable.get()); writer.append(new UndirectedEdge(2, 3), NullWritable.get()); writer.append(new UndirectedEdge(4, 5), NullWritable.get()); writer.append(new UndirectedEdge(4, 7), NullWritable.get()); } finally { Closeables.closeQuietly(writer); } AugmentGraphWithDegreesJob augmentGraphWithDegreesJob = new AugmentGraphWithDegreesJob(); augmentGraphWithDegreesJob.setConf(conf); augmentGraphWithDegreesJob.run(new String[] { "--input", inputFile.getAbsolutePath(), "--output", outputDir.getAbsolutePath(), "--tempDir", tempDir.getAbsolutePath() }); Set<UndirectedEdgeWithDegrees> edges = Sets.newHashSet(); for (Pair<UndirectedEdgeWithDegrees, NullWritable> result : new SequenceFileIterable<UndirectedEdgeWithDegrees, NullWritable>( new Path(outputDir.getAbsolutePath() + "/part-r-00000"), false, conf)) { edges.add(result.getFirst()); } assertEquals(12, edges.size()); assertTrue(edges.contains(new UndirectedEdgeWithDegrees(0, 7, 1, 3))); assertTrue(edges.contains(new UndirectedEdgeWithDegrees(0, 7, 2, 3))); assertTrue(edges.contains(new UndirectedEdgeWithDegrees(0, 7, 3, 3))); assertTrue(edges.contains(new UndirectedEdgeWithDegrees(0, 7, 4, 3))); assertTrue(edges.contains(new UndirectedEdgeWithDegrees(0, 7, 5, 2))); assertTrue(edges.contains(new UndirectedEdgeWithDegrees(0, 7, 6, 1))); assertTrue(edges.contains(new UndirectedEdgeWithDegrees(0, 7, 7, 2))); assertTrue(edges.contains(new UndirectedEdgeWithDegrees(1, 3, 2, 3))); assertTrue(edges.contains(new UndirectedEdgeWithDegrees(1, 3, 3, 3))); assertTrue(edges.contains(new UndirectedEdgeWithDegrees(2, 3, 3, 3))); assertTrue(edges.contains(new UndirectedEdgeWithDegrees(4, 3, 5, 2))); assertTrue(edges.contains(new UndirectedEdgeWithDegrees(4, 3, 7, 2))); } }