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* Licensed to the Apache Software Foundation (ASF) under one
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* 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,
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* See the License for the specific language governing permissions and
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*/
package org.apache.flink.test.iterative;
import java.io.BufferedReader;
import org.apache.flink.api.common.functions.MapFunction;
import org.apache.flink.api.java.DataSet;
import org.apache.flink.api.java.ExecutionEnvironment;
import org.apache.flink.api.java.aggregation.Aggregations;
import org.apache.flink.api.java.operators.DeltaIteration;
import org.apache.flink.api.java.tuple.Tuple1;
import org.apache.flink.api.java.tuple.Tuple2;
import org.apache.flink.examples.java.graph.ConnectedComponents.ComponentIdFilter;
import org.apache.flink.examples.java.graph.ConnectedComponents.NeighborWithComponentIDJoin;
import org.apache.flink.examples.java.graph.ConnectedComponents.UndirectEdge;
import org.apache.flink.test.testdata.ConnectedComponentsData;
import org.apache.flink.test.util.JavaProgramTestBase;
@SuppressWarnings("serial")
public class ConnectedComponentsWithObjectMapITCase extends JavaProgramTestBase {
private static final long SEED = 0xBADC0FFEEBEEFL;
private static final int NUM_VERTICES = 1000;
private static final int NUM_EDGES = 10000;
protected String verticesPath;
protected String edgesPath;
protected String resultPath;
@Override
protected void preSubmit() throws Exception {
verticesPath = createTempFile("vertices.txt", ConnectedComponentsData.getEnumeratingVertices(NUM_VERTICES));
edgesPath = createTempFile("edges.txt", ConnectedComponentsData.getRandomOddEvenEdges(NUM_EDGES, NUM_VERTICES, SEED));
resultPath = getTempFilePath("results");
}
@Override
protected void postSubmit() throws Exception {
for (BufferedReader reader : getResultReader(resultPath)) {
ConnectedComponentsData.checkOddEvenResult(reader);
}
}
@Override
protected void testProgram() throws Exception {
// set up execution environment
ExecutionEnvironment env = ExecutionEnvironment.getExecutionEnvironment();
// read vertex and edge data
DataSet<Tuple1<Long>> vertices = env.readCsvFile(verticesPath).types(Long.class);
DataSet<Tuple2<Long, Long>> edges = env.readCsvFile(edgesPath).fieldDelimiter(' ').types(Long.class, Long.class)
.flatMap(new UndirectEdge());
// assign the initial components (equal to the vertex id)
DataSet<Tuple2<Long, Long>> verticesWithInitialId = vertices.map(new DuplicateValue<Long>());
// open a delta iteration
DeltaIteration<Tuple2<Long, Long>, Tuple2<Long, Long>> iteration =
verticesWithInitialId.iterateDelta(verticesWithInitialId, 100, 0);
iteration.setSolutionSetUnManaged(true);
// apply the step logic: join with the edges, select the minimum neighbor, update if the component of the candidate is smaller
DataSet<Tuple2<Long, Long>> changes = iteration.getWorkset().join(edges).where(0).equalTo(0).with(new NeighborWithComponentIDJoin())
.groupBy(0).aggregate(Aggregations.MIN, 1)
.join(iteration.getSolutionSet()).where(0).equalTo(0)
.with(new ComponentIdFilter());
// close the delta iteration (delta and new workset are identical)
DataSet<Tuple2<Long, Long>> result = iteration.closeWith(changes, changes);
result.writeAsCsv(resultPath, "\n", " ");
// execute program
env.execute("Connected Components Example");
}
public static final class DuplicateValue<T> implements MapFunction<Tuple1<T>, Tuple2<T, T>> {
@Override
public Tuple2<T, T> map(Tuple1<T> vertex) {
return new Tuple2<T, T>(vertex.f0, vertex.f0);
}
}
}