org.apache.jena.grande.giraph.sssps.SingleSourceShortestPaths.java Source code

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/*
 * 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.jena.grande.giraph.sssps;

import java.io.IOException;

import org.apache.giraph.GiraphConfiguration;
import org.apache.giraph.ImmutableClassesGiraphConfiguration;
import org.apache.giraph.graph.Edge;
import org.apache.giraph.graph.EdgeListVertex;
import org.apache.giraph.graph.GiraphJob;
import org.apache.giraph.io.IdWithValueTextOutputFormat;
import org.apache.giraph.io.IntIntNullIntTextInputFormat;
import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.fs.FileSystem;
import org.apache.hadoop.fs.Path;
import org.apache.hadoop.io.IntWritable;
import org.apache.hadoop.io.NullWritable;
import org.apache.hadoop.mapreduce.lib.input.FileInputFormat;
import org.apache.hadoop.mapreduce.lib.output.FileOutputFormat;
import org.apache.hadoop.util.Tool;
import org.apache.hadoop.util.ToolRunner;
import org.apache.jena.grande.Constants;
import org.apache.jena.grande.Utils;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import com.google.common.base.Preconditions;

public class SingleSourceShortestPaths extends EdgeListVertex<IntWritable, IntWritable, NullWritable, IntWritable>
        implements Tool {

    private static final Logger log = LoggerFactory.getLogger(SingleSourceShortestPaths.class);

    public static final String SOURCE_VERTEX = "giraph.example.source";
    public static final int SOURCE_VERTEX_DEFAULT = 3;

    @Override
    public int run(String[] args) throws Exception {
        log.debug("run({})", Utils.toString(args));
        Preconditions.checkArgument(args.length == 4,
                "run: Must have 4 arguments <input path> <output path> <source vertex> <# of workers>");

        Configuration configuration = getConf();
        boolean overrideOutput = configuration.getBoolean(Constants.OPTION_OVERWRITE_OUTPUT,
                Constants.OPTION_OVERWRITE_OUTPUT_DEFAULT);
        FileSystem fs = FileSystem.get(new Path(args[1]).toUri(), configuration);
        if (overrideOutput) {
            fs.delete(new Path(args[1]), true);
        }

        GiraphConfiguration giraphConfiguration = new GiraphConfiguration(getConf());
        giraphConfiguration.setVertexClass(getClass());
        giraphConfiguration.setVertexInputFormatClass(IntIntNullIntTextInputFormat.class);
        giraphConfiguration.setVertexOutputFormatClass(IdWithValueTextOutputFormat.class);
        giraphConfiguration.set(SOURCE_VERTEX, args[2]);
        giraphConfiguration.setWorkerConfiguration(Integer.parseInt(args[3]), Integer.parseInt(args[3]), 100.0f);

        GiraphJob job = new GiraphJob(giraphConfiguration, getClass().getName());
        FileInputFormat.addInputPath(job.getInternalJob(), new Path(args[0]));
        FileOutputFormat.setOutputPath(job.getInternalJob(), new Path(args[1]));
        return job.run(true) ? 0 : -1;
    }

    @Override
    public void compute(Iterable<IntWritable> msgIterator) throws IOException {
        log.debug("compute(...)::{}#{} ...", getId(), getSuperstep());
        if ((getSuperstep() == 0) || (getSuperstep() == 1)) {
            setValue(new IntWritable(Integer.MAX_VALUE));
        }
        int minDist = isSource() ? 0 : Integer.MAX_VALUE;
        log.debug("compute(...)::{}#{}: min = {}, value = {}",
                new Object[] { getId(), getSuperstep(), minDist, getValue() });
        for (IntWritable msg : msgIterator) {
            log.debug("compute(...)::{}#{}: <--[{}]-- from ?", new Object[] { getId(), getSuperstep(), msg });
            minDist = Math.min(minDist, msg.get());
            log.debug("compute(...)::{}#{}: min = {}", new Object[] { getId(), getSuperstep(), minDist });
        }
        if (minDist < getValue().get()) {
            setValue(new IntWritable(minDist));
            log.debug("compute(...)::{}#{}: value = {}", new Object[] { getId(), getSuperstep(), getValue() });
            for (Edge<IntWritable, NullWritable> edge : getEdges()) {
                log.debug("compute(...)::{}#{}: {} --[{}]--> {}",
                        new Object[] { getId(), getSuperstep(), getId(), minDist + 1, edge.getTargetVertexId() });
                sendMessage(edge.getTargetVertexId(), new IntWritable(minDist + 1));
            }
        }
        voteToHalt();
    }

    private boolean isSource() {
        boolean result = getId().get() == getConf().getInt(SOURCE_VERTEX, SOURCE_VERTEX_DEFAULT);
        log.debug("isSource() --> {}", result);
        return result;
    }

    @Override
    public void setConf(Configuration conf) {
        super.setConf(
                new ImmutableClassesGiraphConfiguration<IntWritable, IntWritable, NullWritable, IntWritable>(conf));
    }

    public static void main(String[] args) throws Exception {
        log.debug("main({})", Utils.toString(args));
        System.exit(ToolRunner.run(new SingleSourceShortestPaths(), args));
    }

}