MultipleOutputsCommitter.java

/*
 * Copyright © 2015 Cask Data, Inc.
 *
 * Licensed 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 co.cask.cdap.internal.app.runtime.batch.dataset.output;

import com.google.common.collect.ImmutableMap;
import org.apache.hadoop.mapreduce.JobContext;
import org.apache.hadoop.mapreduce.JobStatus;
import org.apache.hadoop.mapreduce.OutputCommitter;
import org.apache.hadoop.mapreduce.TaskAttemptContext;

import java.io.IOException;
import java.util.Map;

/**
 * OutputCommitter that delegates to a collection of other OutputFormatCommitters.
 */
public class MultipleOutputsCommitter extends OutputCommitter {

  private final Map<String, OutputCommitter> committers;

  public MultipleOutputsCommitter(Map<String, OutputCommitter> committers) {
    this.committers = ImmutableMap.copyOf(committers);
  }

  @Override
  public void setupJob(JobContext jobContext) throws IOException {
    for (Map.Entry<String, OutputCommitter> committer : committers.entrySet()) {
      JobContext namedJobContext = MultipleOutputs.getNamedJobContext(jobContext, committer.getKey());
      committer.getValue().setupJob(namedJobContext);
    }
  }

  @Override
  public void setupTask(TaskAttemptContext taskContext) throws IOException {
    for (Map.Entry<String, OutputCommitter> committer : committers.entrySet()) {
      TaskAttemptContext namedTaskContext = MultipleOutputs.getNamedTaskContext(taskContext, committer.getKey());
      committer.getValue().setupTask(namedTaskContext);
    }
  }

  @Override
  public boolean needsTaskCommit(TaskAttemptContext taskContext) throws IOException {
    // needs task commit if any delegates need task commit
    for (Map.Entry<String, OutputCommitter> committer : committers.entrySet()) {
      TaskAttemptContext namedTaskContext = MultipleOutputs.getNamedTaskContext(taskContext, committer.getKey());
      if (committer.getValue().needsTaskCommit(namedTaskContext)) {
        return true;
      }
    }
    return false;
  }

  @Override
  public void commitTask(TaskAttemptContext taskContext) throws IOException {
    for (Map.Entry<String, OutputCommitter> committer : committers.entrySet()) {
      TaskAttemptContext namedTaskContext = MultipleOutputs.getNamedTaskContext(taskContext, committer.getKey());
      if (committer.getValue().needsTaskCommit(namedTaskContext)) {
        committer.getValue().commitTask(namedTaskContext);
      }
    }
  }

  @Override
  public void abortTask(TaskAttemptContext taskContext) throws IOException {
    for (Map.Entry<String, OutputCommitter> committer : committers.entrySet()) {
      TaskAttemptContext namedTaskContext = MultipleOutputs.getNamedTaskContext(taskContext, committer.getKey());
      committer.getValue().abortTask(namedTaskContext);
    }
  }

  @Override
  public void commitJob(JobContext jobContext) throws IOException {
    for (Map.Entry<String, OutputCommitter> committer : committers.entrySet()) {
      JobContext namedJobContext = MultipleOutputs.getNamedJobContext(jobContext, committer.getKey());
      committer.getValue().commitJob(namedJobContext);
    }
  }

  @Override
  public void abortJob(JobContext jobContext, JobStatus.State state) throws IOException {
    for (Map.Entry<String, OutputCommitter> committer : committers.entrySet()) {
      JobContext namedJobContext = MultipleOutputs.getNamedJobContext(jobContext, committer.getKey());
      committer.getValue().abortJob(namedJobContext, state);
    }
  }

  @Override
  public boolean isRecoverySupported() {
    // recovery is supported if it is supported on all delegates
    for (OutputCommitter committer : committers.values()) {
      if (!committer.isRecoverySupported()) {
        return false;
      }
    }
    return true;
  }

  @Override
  public void recoverTask(TaskAttemptContext taskContext) throws IOException {
    for (Map.Entry<String, OutputCommitter> committer : committers.entrySet()) {
      TaskAttemptContext namedTaskContext = MultipleOutputs.getNamedTaskContext(taskContext, committer.getKey());
      committer.getValue().recoverTask(namedTaskContext);
    }
  }
}