co.cask.cdap.internal.app.runtime.batch.MapReduceBatchReadableInputFormat.java Source code

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Here is the source code for co.cask.cdap.internal.app.runtime.batch.MapReduceBatchReadableInputFormat.java

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/*
 * 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;

import co.cask.cdap.api.data.batch.BatchReadable;
import co.cask.cdap.internal.app.runtime.batch.dataset.AbstractBatchReadableInputFormat;
import org.apache.hadoop.mapreduce.InputFormat;
import org.apache.hadoop.mapreduce.TaskAttemptContext;

import java.util.Map;

/**
 * An {@link InputFormat} for reading data from {@link BatchReadable} for MapReduce.
 * @param <KEY> Type of key.
 * @param <VALUE> Type of value.
 */
public final class MapReduceBatchReadableInputFormat<KEY, VALUE>
        extends AbstractBatchReadableInputFormat<KEY, VALUE> {

    @Override
    protected BatchReadable<KEY, VALUE> createBatchReadable(TaskAttemptContext context, String datasetName,
            Map<String, String> datasetArgs) {

        MapReduceClassLoader classLoader = MapReduceClassLoader.getFromConfiguration(context.getConfiguration());
        BasicMapReduceTaskContext<?, ?> taskContext = classLoader.getTaskContextProvider().get(context);
        return taskContext.getBatchReadable(datasetName, datasetArgs);
    }
}