content: /*
   * 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
   *
   *     https://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.avro.mapred.tether;
  
  import java.nio.ByteBuffer;
  
  import org.apache.hadoop.io.NullWritable;
  import org.apache.hadoop.mapred.OutputCollector;
  import org.apache.hadoop.mapred.Reporter;
  import org.slf4j.Logger;
  import org.slf4j.LoggerFactory;
  
  class TetherOutputService implements OutputProtocol {
    private Reporter reporter;
    private OutputCollector<TetherData, NullWritable> collector;
    private int inputPort;
    private boolean complete;
    private String error;
  
    private static final Logger LOG = LoggerFactory.getLogger(TetherOutputService.class);
  
    // timeout when waiting for messages in seconds.
    // what is a good value?
    public static final long TIMEOUT = 10 * 1000;
  
    public TetherOutputService(OutputCollector<TetherData, NullWritable> collector, Reporter reporter) {
      this.reporter = reporter;
      this.collector = collector;
    }
  
    @Override
    public synchronized void configure(int inputPort) {
      LOG.info("got input port from child: inputport=" + inputPort);
      this.inputPort = inputPort;
      notify();
    }
  
    public synchronized int inputPort() throws Exception {
      if (inputPort == 0) {
        LOG.info("waiting for input port from child");
        wait(TIMEOUT);
      }
  
      if (inputPort == 0) {
        LOG.error(
            "Parent process timed out waiting for subprocess to send input port. Check the job log files for more info.");
        throw new Exception("Parent process timed out waiting for subprocess to send input port");
      }
      return inputPort;
    }
  
    @Override
    public void output(ByteBuffer datum) {
      try {
        collector.collect(new TetherData(datum), NullWritable.get());
      } catch (Throwable e) {
        LOG.warn("Error: " + e, e);
        synchronized (this) {
          error = e.toString();
        }
      }
    }
  
    @Override
    public void outputPartitioned(int partition, ByteBuffer datum) {
      TetherPartitioner.setNextPartition(partition);
      output(datum);
    }
  
    @Override
    public void status(String message) {
      reporter.setStatus(message.toString());
    }
  
    @Override
    public void count(String group, String name, long amount) {
      reporter.getCounter(group.toString(), name.toString()).increment(amount);
    }
  
    @Override
    public synchronized void fail(String message) {
      LOG.warn("Failing: " + message);
      error = message;
      notify();
    }
  
    @Override
    public synchronized void complete() {
      LOG.info("got task complete");
      complete = true;
      notify();
    }
  
    public synchronized boolean isFinished() {
      return complete || (error != null);
    }
  
    public String error() {
      return error;
    }
  
    public synchronized boolean waitForFinish() throws InterruptedException {
      while (!isFinished())
        wait();
      return error != null;
    }
  
  }
  