content: package hip.ch3.proto;
  
  import com.hadoop.compression.lzo.LzopCodec;
  import com.twitter.elephantbird.mapreduce.input.LzoProtobufBlockInputFormat;
  import com.twitter.elephantbird.mapreduce.input.MultiInputFormat;
  import com.twitter.elephantbird.mapreduce.io.ProtobufBlockWriter;
  import com.twitter.elephantbird.mapreduce.io.ProtobufWritable;
  import com.twitter.elephantbird.mapreduce.output.LzoProtobufBlockOutputFormat;
  import com.twitter.elephantbird.util.TypeRef;
  import hip.util.Cli;
  import org.apache.hadoop.conf.Configuration;
  import org.apache.hadoop.conf.Configured;
  import org.apache.hadoop.fs.FileSystem;
  import org.apache.hadoop.fs.Path;
  import org.apache.hadoop.io.IOUtils;
  import org.apache.hadoop.io.LongWritable;
  import org.apache.hadoop.io.NullWritable;
  import org.apache.hadoop.io.Text;
  import org.apache.hadoop.mapreduce.Job;
  import org.apache.hadoop.mapreduce.Mapper;
  import org.apache.hadoop.mapreduce.Reducer;
  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 java.io.File;
  import java.io.IOException;
  import java.io.OutputStream;
  
  import static hip.ch3.proto.StockProtos.Stock;
  import static hip.ch3.proto.StockProtos.StockAvg;
  
  
  public class StockProtocolBuffersMapReduce extends Configured implements Tool {
  
    public static class ProtobufStockWritable
        extends ProtobufWritable<Stock> {
      public ProtobufStockWritable() {
        super(new TypeRef<Stock>() {
        });
      }
  
      public ProtobufStockWritable(Stock m) {
        super(m, new TypeRef<Stock>() {
        });
      }
    }
  
    /**
     * Main entry point for the example.
     *
     * @param args arguments
     * @throws Exception when something goes wrong
     */
    public static void main(final String[] args) throws Exception {
      int res = ToolRunner.run(new Configuration(), new StockProtocolBuffersMapReduce(), args);
      System.exit(res);
    }
  
    /**
     * The MapReduce driver - setup and launch the job.
     *
     * @param args the command-line arguments
     * @return the process exit code
     * @throws Exception if something goes wrong
     */
    public int run(final String[] args) throws Exception {
  
  
      Cli cli = Cli.builder().setArgs(args).addOptions(Opts.values()).build();
      int result = cli.runCmd();
  
      if (result != 0) {
        return result;
      }
  
      File localStocksFile = new File(cli.getArgValueAsString(Opts.INPUT));
      Path inputPath = new Path(cli.getArgValueAsString(Opts.PB_INPUT));
      Path outputPath = new Path(cli.getArgValueAsString(Opts.OUTPUT));
  
      Configuration conf = super.getConf();
  
      if (!inputPath.getName().endsWith(".lzo")) {
        throw new Exception("HDFS stock file must have a .lzo suffix");
      }
  
      generateInput(conf, localStocksFile, inputPath);
  
      Job job = new Job(conf);
      job.setJobName(StockProtocolBuffersMapReduce.class.getName());
  
      job.setJarByClass(StockProtocolBuffersMapReduce.class);
      job.setMapperClass(PBMapper.class);
      job.setReducerClass(PBReducer.class);
  
      job.setMapOutputKeyClass(Text.class);
      job.setMapOutputValueClass(ProtobufStockWritable.class);
  
      MultiInputFormat.setClassConf(Stock.class, job.getConfiguration());
      LzoProtobufBlockOutputFormat.setClassConf(StockAvg.class, job.getConfiguration());
  
      job.setInputFormatClass(LzoProtobufBlockInputFormat.class);
      job.setOutputFormatClass(LzoProtobufBlockOutputFormat.class);
  
      FileInputFormat.setInputPaths(job, inputPath);
      FileOutputFormat.setOutputPath(job, outputPath);
  
      if (job.waitForCompletion(true)) {
        return 0;
      }
      return 1;
    }
  
    private static void generateInput(Configuration config,
                                      File inputFile,
                                      Path input) throws IOException {
      FileSystem hdfs = FileSystem.get(config);
      OutputStream os = hdfs.create(input);
  
      LzopCodec codec = new LzopCodec();
      codec.setConf(config);
      OutputStream lzopOutputStream = codec.createOutputStream(os);
  
      ProtobufBlockWriter<Stock> writer =
          new ProtobufBlockWriter<Stock>(
              lzopOutputStream, Stock.class);
  
      for (Stock stock : StockUtils.fromCsvFile(inputFile)) {
        writer.write(stock);
      }
      writer.finish();
      writer.close();
      IOUtils.closeStream(os);
    }
  
    public static class PBMapper extends
        Mapper<LongWritable, ProtobufWritable<Stock>,
            Text, ProtobufStockWritable> {
      @Override
      protected void map(LongWritable key,
                         ProtobufWritable<Stock> value,
                         Context context) throws IOException,
          InterruptedException {
        context.write(
            new Text(value.get().getSymbol()),
            new ProtobufStockWritable(value.get()));
      }
    }
  
    public static class PBReducer extends
        Reducer<Text, ProtobufStockWritable,
            NullWritable, ProtobufWritable> {
      private ProtobufWritable<StockAvg> stockAvg =
          new ProtobufWritable<StockAvg>();
  
      @Override
      protected void reduce(Text symbol,
                            Iterable<ProtobufStockWritable> values,
                            Context context) throws IOException,
          InterruptedException {
        double total = 0.0;
        double count = 0;
        for (ProtobufStockWritable d : values) {
          total += d.get().getOpen();
          count++;
        }
        StockAvg avg = StockAvg.newBuilder()
            .setSymbol(symbol.toString())
            .setAvg(total / count).build();
        stockAvg.set(avg);
        context.write(NullWritable.get(), stockAvg);
      }
    }
  
    public enum Opts implements Cli.ArgGetter {
      INPUT(Cli.ArgBuilder.builder().hasArgument(true).required(true).description("Input file or directory")),
      PB_INPUT(Cli.ArgBuilder.builder().hasArgument(true).required(true).description("Protobuf file")),
      OUTPUT(Cli.ArgBuilder.builder().hasArgument(true).required(true).description("HDFS output directory"));
      private final Cli.ArgInfo argInfo;
  
      Opts(final Cli.ArgBuilder builder) {
        this.argInfo = builder.setArgName(name()).build();
      }
  
      @Override
      public Cli.ArgInfo getArgInfo() {
        return argInfo;
      }
    }
  }
  