AbstractMapReduce.java

/*
 * Copyright © 2014-2016 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.api.mapreduce;

import co.cask.cdap.api.Resources;
import co.cask.cdap.api.data.batch.Input;
import co.cask.cdap.api.data.batch.Output;
import co.cask.cdap.api.data.stream.StreamBatchReadable;
import co.cask.cdap.internal.api.AbstractPluginConfigurable;

import java.util.ArrayList;
import java.util.Arrays;
import java.util.List;
import java.util.Map;

/**
 * This abstract class provides a default implementation of {@link MapReduce} methods for easy extension.
 */
public abstract class AbstractMapReduce extends AbstractPluginConfigurable<MapReduceConfigurer>
  implements MapReduce {

  private MapReduceConfigurer configurer;

  @Override
  public final void configure(MapReduceConfigurer configurer) {
    this.configurer = configurer;
    configure();
  }

  /**
   * Override this method to configure this {@link MapReduce} job.
   */
  protected void configure() {
    // Default no-op
  }

  /**
   * Returns the {@link MapReduceConfigurer}, only available at configuration time.
   */
  @Override
  protected final MapReduceConfigurer getConfigurer() {
    return configurer;
  }

  /**
   * Sets the name of the {@link MapReduce}.
   */
  protected final void setName(String name) {
    configurer.setName(name);
  }

  /**
   * Sets the description of the {@link MapReduce}.
   */
  protected final void setDescription(String description) {
    configurer.setDescription(description);
  }

  /**
   * Sets a set of properties that will be available through the {@link MapReduceSpecification#getProperties()}
   * at runtime.
   *
   * @param properties the properties to set
   */
  protected final void setProperties(Map<String, String> properties) {
    configurer.setProperties(properties);
  }

  /**
   * Sets the resources requirement for the driver of the {@link MapReduce}.
   */
  protected final void setDriverResources(Resources resources) {
    configurer.setDriverResources(resources);
  }

  /**
   * Sets the resources requirement for Mapper task of the {@link MapReduce}.
   */
  protected final void setMapperResources(Resources resources) {
    configurer.setMapperResources(resources);
  }

  /**
   * Sets the resources requirement for Reducer task of the {@link MapReduce}.
   */
  protected final void setReducerResources(Resources resources) {
    configurer.setReducerResources(resources);
  }

  /**
   * Specifies set of Dataset names that are used by the {@link MapReduce}.
   * @deprecated Deprecated as of 2.8.0. Dataset can be requested directly through the method
   *             {@link MapReduceContext#getDataset(String)} or
   *             {@link MapReduceTaskContext#getDataset(String)} at runtime.
   */
  @Deprecated
  protected final void useDatasets(String dataset, String...moreDatasets) {
    List<String> datasets = new ArrayList<>();
    datasets.add(dataset);
    datasets.addAll(Arrays.asList(moreDatasets));
    configurer.useDatasets(datasets);
  }

  /**
   * Specifies set of Dataset names that are used by the {@link MapReduce}.
   * @deprecated Deprecated as of 2.8.0. Dataset can be requested directly through the method
   *             {@link MapReduceContext#getDataset(String)} or
   *             {@link MapReduceTaskContext#getDataset(String)} at runtime.
   */
  @Deprecated
  protected final void useDatasets(Iterable<String> datasets) {
    configurer.useDatasets(datasets);
  }

  /**
   * Sets the name of the Dataset used as input for the {@link MapReduce}.
   *
   * @deprecated as of 3.4.0. Use {@link MapReduceContext#addInput(Input)}
   * in {@link #beforeSubmit}, instead.
   */
  @Deprecated
  protected final void setInputDataset(String dataset) {
    configurer.setInputDataset(dataset);
  }

  /**
   * Uses Stream as input for the {@link MapReduce}.
   *
   * @param stream Name of the stream
   * @deprecated as of 3.4.0. Use {@link MapReduceContext#addInput(Input)}
   *             in {@link #beforeSubmit}, instead.
   */
  @Deprecated
  protected final void useStreamInput(String stream) {
    useStreamInput(new StreamBatchReadable(stream));
  }

  /**
   * Uses Stream as input for the {@link MapReduce} with specific time range. Same as calling
   * {@link #useStreamInput(StreamBatchReadable) setInputStream(new StreamBatchReadable(stream, startTime, endTime))}.
   *
   * @see StreamBatchReadable
   *
   * @deprecated as of 3.4.0. Use {@link MapReduceContext#addInput(Input)}
   *             in {@link #beforeSubmit}, instead.
   */
  @Deprecated
  protected final void useStreamInput(String stream, long startTime, long endTime) {
    useStreamInput(new StreamBatchReadable(stream, startTime, endTime));
  }

  /**
   * Uses Stream as input for the {@link MapReduce}.
   *
   * @see StreamBatchReadable
   *
   * @deprecated as of 3.4.0. Use {@link MapReduceContext#addInput(Input)}
   *             in {@link #beforeSubmit}, instead.
   */
  @Deprecated
  protected final void useStreamInput(StreamBatchReadable streamBatchReadable) {
    configurer.setInputDataset(streamBatchReadable.toURI().toString());
  }

  /**
   * Sets the name of the Dataset used as output for the {@link MapReduce}.
   *
   * @deprecated as of 3.2.0. Use {@link MapReduceContext#addOutput(Output output)}
   *             in {@link #beforeSubmit}, instead.
   */
  @Deprecated
  protected final void setOutputDataset(String dataset) {
    configurer.setOutputDataset(dataset);
  }

  @Override
  public void beforeSubmit(MapReduceContext context) throws Exception {
    // Do nothing by default
  }

  @Override
  public void onFinish(boolean succeeded, MapReduceContext context) throws Exception {
    // Do nothing by default
  }
}