org.gridgain.grid.kernal.processors.hadoop.v1.GridHadoopV1MapTask.java Source code

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Here is the source code for org.gridgain.grid.kernal.processors.hadoop.v1.GridHadoopV1MapTask.java

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/* 
 Copyright (C) GridGain Systems. All Rights Reserved.
     
 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 org.gridgain.grid.kernal.processors.hadoop.v1;

import org.apache.hadoop.fs.*;
import org.apache.hadoop.mapred.*;
import org.apache.hadoop.util.*;
import org.gridgain.grid.*;
import org.gridgain.grid.hadoop.*;
import org.gridgain.grid.kernal.processors.hadoop.*;
import org.gridgain.grid.kernal.processors.hadoop.v2.*;

/**
 * Hadoop map task implementation for v1 API.
 */
public class GridHadoopV1MapTask extends GridHadoopV1Task {
    /** */
    private static final String[] EMPTY_HOSTS = new String[0];

    /** {@inheritDoc} */
    public GridHadoopV1MapTask(GridHadoopTaskInfo taskInfo) {
        super(taskInfo);
    }

    /** {@inheritDoc} */
    @SuppressWarnings("unchecked")
    @Override
    public void run(GridHadoopTaskContext taskCtx) throws GridException {
        GridHadoopJob job = taskCtx.job();

        GridHadoopV2TaskContext ctx = (GridHadoopV2TaskContext) taskCtx;

        JobConf jobConf = ctx.jobConf();

        InputFormat inFormat = jobConf.getInputFormat();

        GridHadoopInputSplit split = info().inputSplit();

        InputSplit nativeSplit;

        if (split instanceof GridHadoopFileBlock) {
            GridHadoopFileBlock block = (GridHadoopFileBlock) split;

            nativeSplit = new FileSplit(new Path(block.file().toString()), block.start(), block.length(),
                    EMPTY_HOSTS);
        } else
            nativeSplit = (InputSplit) ctx.getNativeSplit(split);

        assert nativeSplit != null;

        Reporter reporter = new GridHadoopV1Reporter(taskCtx);

        GridHadoopV1OutputCollector collector = null;

        try {
            collector = collector(jobConf, ctx, !job.info().hasCombiner() && !job.info().hasReducer(), fileName(),
                    ctx.attemptId());

            RecordReader reader = inFormat.getRecordReader(nativeSplit, jobConf, reporter);

            Mapper mapper = ReflectionUtils.newInstance(jobConf.getMapperClass(), jobConf);

            Object key = reader.createKey();
            Object val = reader.createValue();

            assert mapper != null;

            try {
                try {
                    while (reader.next(key, val)) {
                        if (isCancelled())
                            throw new GridHadoopTaskCancelledException("Map task cancelled.");

                        mapper.map(key, val, collector, reporter);
                    }
                } finally {
                    mapper.close();
                }
            } finally {
                collector.closeWriter();
            }

            collector.commit();
        } catch (Exception e) {
            if (collector != null)
                collector.abort();

            throw new GridException(e);
        }
    }
}