| /* |
| * 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.tinkerpop.gremlin.hadoop.process.computer; |
| |
| import org.apache.commons.configuration.Configuration; |
| import org.apache.hadoop.io.NullWritable; |
| import org.apache.hadoop.mapreduce.Mapper; |
| import org.apache.tinkerpop.gremlin.hadoop.structure.HadoopGraph; |
| import org.apache.tinkerpop.gremlin.hadoop.structure.io.HadoopPools; |
| import org.apache.tinkerpop.gremlin.hadoop.structure.io.ObjectWritable; |
| import org.apache.tinkerpop.gremlin.hadoop.structure.io.VertexWritable; |
| import org.apache.tinkerpop.gremlin.hadoop.structure.util.ConfUtil; |
| import org.apache.tinkerpop.gremlin.process.computer.MapReduce; |
| import org.apache.tinkerpop.gremlin.process.computer.util.ComputerGraph; |
| import org.slf4j.Logger; |
| import org.slf4j.LoggerFactory; |
| |
| import java.io.IOException; |
| import java.util.Optional; |
| |
| /** |
| * @author Marko A. Rodriguez (http://markorodriguez.com) |
| */ |
| public final class HadoopMap extends Mapper<NullWritable, VertexWritable, ObjectWritable, ObjectWritable> { |
| |
| private static final Logger LOGGER = LoggerFactory.getLogger(HadoopMap.class); |
| private MapReduce mapReduce; |
| private final HadoopMapEmitter<ObjectWritable, ObjectWritable> mapEmitter = new HadoopMapEmitter<>(); |
| |
| private HadoopMap() { |
| |
| } |
| |
| @Override |
| public void setup(final Mapper<NullWritable, VertexWritable, ObjectWritable, ObjectWritable>.Context context) { |
| final Configuration apacheConfiguration = ConfUtil.makeApacheConfiguration(context.getConfiguration()); |
| HadoopPools.initialize(apacheConfiguration); |
| this.mapReduce = MapReduce.createMapReduce(HadoopGraph.open(apacheConfiguration), apacheConfiguration); |
| this.mapReduce.workerStart(MapReduce.Stage.MAP); |
| } |
| |
| @Override |
| public void map(final NullWritable key, final VertexWritable value, final Mapper<NullWritable, VertexWritable, ObjectWritable, ObjectWritable>.Context context) throws IOException, InterruptedException { |
| this.mapEmitter.setContext(context); |
| this.mapReduce.map(ComputerGraph.mapReduce(value.get()), this.mapEmitter); |
| } |
| |
| @Override |
| public void cleanup(final Mapper<NullWritable, VertexWritable, ObjectWritable, ObjectWritable>.Context context) { |
| this.mapReduce.workerEnd(MapReduce.Stage.MAP); |
| } |
| |
| public class HadoopMapEmitter<K, V> implements MapReduce.MapEmitter<K, V> { |
| |
| private Mapper<NullWritable, VertexWritable, ObjectWritable, ObjectWritable>.Context context; |
| private final ObjectWritable<K> keyWritable = new ObjectWritable<>(); |
| private final ObjectWritable<V> valueWritable = new ObjectWritable<>(); |
| |
| public void setContext(final Mapper<NullWritable, VertexWritable, ObjectWritable, ObjectWritable>.Context context) { |
| this.context = context; |
| } |
| |
| @Override |
| public void emit(final K key, final V value) { |
| this.keyWritable.set(key); |
| this.valueWritable.set(value); |
| try { |
| this.context.write(this.keyWritable, this.valueWritable); |
| } catch (final Exception e) { |
| LOGGER.error(e.getMessage()); |
| throw new IllegalStateException(e.getMessage(), e); |
| } |
| } |
| } |
| } |