SparkAppUsingFileSet.java

/*
 * Copyright © 2016 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.spark.app;

import co.cask.cdap.api.app.AbstractApplication;
import co.cask.cdap.api.data.batch.DatasetOutputCommitter;
import co.cask.cdap.api.data.batch.InputFormatProvider;
import co.cask.cdap.api.data.batch.OutputFormatProvider;
import co.cask.cdap.api.dataset.DataSetException;
import co.cask.cdap.api.dataset.DatasetSpecification;
import co.cask.cdap.api.dataset.lib.AbstractDataset;
import co.cask.cdap.api.dataset.lib.FileSet;
import co.cask.cdap.api.dataset.lib.FileSetProperties;
import co.cask.cdap.api.dataset.lib.PartitionedFileSet;
import co.cask.cdap.api.dataset.lib.PartitionedFileSetProperties;
import co.cask.cdap.api.dataset.lib.Partitioning;
import co.cask.cdap.api.dataset.lib.TimePartitionedFileSet;
import co.cask.cdap.api.dataset.module.EmbeddedDataset;
import co.cask.cdap.spark.FileCountSparkProgram;
import com.google.common.base.Throwables;
import org.apache.hadoop.io.LongWritable;
import org.apache.hadoop.io.Text;
import org.apache.hadoop.mapreduce.InputFormat;
import org.apache.hadoop.mapreduce.InputSplit;
import org.apache.hadoop.mapreduce.JobContext;
import org.apache.hadoop.mapreduce.RecordReader;
import org.apache.hadoop.mapreduce.RecordWriter;
import org.apache.hadoop.mapreduce.TaskAttemptContext;
import org.apache.hadoop.mapreduce.lib.input.TextInputFormat;
import org.apache.hadoop.mapreduce.lib.output.TextOutputFormat;
import org.apache.twill.filesystem.Location;

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

/**
 * A dummy app with spark program which counts the characters in a string
 */
public class SparkAppUsingFileSet extends AbstractApplication {
  @Override
  public void configure() {
    try {
      createDataset("fs", FileSet.class, FileSetProperties.builder()
        .setInputFormat(MyTextInputFormat.class)
        .setOutputFormat(MyTextOutputFormat.class)
        .setOutputProperty(TextOutputFormat.SEPERATOR, ":").build());
      createDataset("pfs", PartitionedFileSet.class, PartitionedFileSetProperties.builder()
        .setPartitioning(Partitioning.builder().addStringField("x").build())
        .setInputFormat(MyTextInputFormat.class)
        .setOutputFormat(TextOutputFormat.class)
        .setOutputProperty(TextOutputFormat.SEPERATOR, ":").build());
      createDataset("tpfs", TimePartitionedFileSet.class, FileSetProperties.builder()
        .setInputFormat(MyTextInputFormat.class)
        .setOutputFormat(TextOutputFormat.class)
        .setOutputProperty(TextOutputFormat.SEPERATOR, ":").build());
      createDataset("myfs", MyFileSet.class, FileSetProperties.builder()
        .setInputFormat(MyTextInputFormat.class)
        .setOutputFormat(TextOutputFormat.class)
        .setOutputProperty(TextOutputFormat.SEPERATOR, ":").build());
      addSpark(new FileCountSparkProgram());
      addSpark(new ScalaFileCountSparkProgram());
    } catch (Throwable t) {
      throw Throwables.propagate(t);
    }
  }

  /**
   * A custom dataset embedding a fileset. It delegates all operations to the embedded fileset, but it
   * overrides the DatasetOutputCommitter to create a file names "success" or "failure", which can be
   * validated by the test case.
   */
  public static class MyFileSet extends AbstractDataset
    implements InputFormatProvider, OutputFormatProvider, DatasetOutputCommitter {

    private final FileSet delegate;

    public MyFileSet(DatasetSpecification spec, @EmbeddedDataset("files") FileSet embedded) {
      super(spec.getName(), embedded);
      this.delegate = embedded;
    }

    public FileSet getEmbeddedFileSet() {
      return delegate;
    }

    public Location getSuccessLocation() throws IOException {
      return delegate.getBaseLocation().append("success");
    }

    public Location getFailureLocation() throws IOException {
      return delegate.getBaseLocation().append("failure");
    }

    @Override
    public String getInputFormatClassName() {
      return delegate.getInputFormatClassName();
    }

    @Override
    public Map<String, String> getInputFormatConfiguration() {
      return delegate.getInputFormatConfiguration();
    }

    @Override
    public String getOutputFormatClassName() {
      return delegate.getOutputFormatClassName();
    }

    @Override
    public Map<String, String> getOutputFormatConfiguration() {
      return delegate.getOutputFormatConfiguration();
    }

    @Override
    public void onSuccess() throws DataSetException {
      try {
        getSuccessLocation().createNew();
      } catch (Throwable t) {
        throw Throwables.propagate(t);
      }
    }

    @Override
    public void onFailure() throws DataSetException {
      try {
        getFailureLocation().createNew();
      } catch (Throwable t) {
        throw Throwables.propagate(t);
      }
    }
  }

  /**
   * An input format that delegates to TextInputFormat. It is defined in the application and requires
   * the Spark runtime to use the program class loader to load the class.
   */
  public static final class MyTextInputFormat extends InputFormat<Long, String> {

    TextInputFormat delegate = new TextInputFormat();

    @Override
    public List<InputSplit> getSplits(JobContext context) throws IOException, InterruptedException {
      return delegate.getSplits(context);
    }

    @Override
    public RecordReader<Long, String> createRecordReader(InputSplit split, TaskAttemptContext context)
      throws IOException, InterruptedException {
      return new MyRecordReader(delegate.createRecordReader(split, context));
    }
  }

  public static class MyRecordReader extends RecordReader<Long, String> {

    private RecordReader<LongWritable, Text> delegate;

    public MyRecordReader(RecordReader<LongWritable, Text> delegate) {
      this.delegate = delegate;
    }

    @Override
    public void initialize(InputSplit split, TaskAttemptContext context)
      throws IOException, InterruptedException {
      delegate.initialize(split, context);
    }

    @Override
    public boolean nextKeyValue() throws IOException, InterruptedException {
      return delegate.nextKeyValue();
    }

    @Override
    public Long getCurrentKey() throws IOException, InterruptedException {
      LongWritable writable = delegate.getCurrentKey();
      return writable == null ? null : writable.get();
    }

    @Override
    public String getCurrentValue() throws IOException, InterruptedException {
      Text text = delegate.getCurrentValue();
      return text == null ? null : text.toString();
    }

    @Override
    public float getProgress() throws IOException, InterruptedException {
      return delegate.getProgress();
    }

    @Override
    public void close() throws IOException {
      delegate.close();
    }
  }

  public static final class MyTextOutputFormat extends TextOutputFormat<String, Integer> {
    @Override
    public RecordWriter<String, Integer> getRecordWriter(TaskAttemptContext job) throws IOException,
                                                                                        InterruptedException {
      final String prefix = "custom" + job.getConfiguration().get(SEPERATOR);
      final RecordWriter<String, Integer> recordWriter = super.getRecordWriter(job);
      return new RecordWriter<String, Integer>() {
        @Override
        public void write(String key, Integer value) throws IOException, InterruptedException {
          // Prefix the key with "custom" + separator
          recordWriter.write(prefix + key, value);
        }

        @Override
        public void close(TaskAttemptContext context) throws IOException, InterruptedException {
          recordWriter.close(context);
        }
      };
    }
  }
}