org.gridgain.grid.kernal.processors.hadoop.v1.GridHadoopV1Splitter.java Source code

Introduction

Here is the source code for org.gridgain.grid.kernal.processors.hadoop.v1.GridHadoopV1Splitter.java

Source

/* 
 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.gridgain.grid.*;
import org.gridgain.grid.hadoop.*;
import org.gridgain.grid.kernal.processors.hadoop.*;
import org.gridgain.grid.util.typedef.internal.*;
import org.jetbrains.annotations.*;

import java.io.*;
import java.util.*;

/**
 * Hadoop API v1 splitter.
 */
public class GridHadoopV1Splitter {
    /** */
    private static final String[] EMPTY_HOSTS = {};

    /**
     * @param jobConf Job configuration.
     * @return Collection of mapped splits.
     * @throws GridException If mapping failed.
     */
    public static Collection<GridHadoopInputSplit> splitJob(JobConf jobConf) throws GridException {
        try {
            InputFormat<?, ?> format = jobConf.getInputFormat();

            assert format != null;

            InputSplit[] splits = format.getSplits(jobConf, 0);

            Collection<GridHadoopInputSplit> res = new ArrayList<>(splits.length);

            for (int i = 0; i < splits.length; i++) {
                InputSplit nativeSplit = splits[i];

                if (nativeSplit instanceof FileSplit) {
                    FileSplit s = (FileSplit) nativeSplit;

                    res.add(new GridHadoopFileBlock(s.getLocations(), s.getPath().toUri(), s.getStart(),
                            s.getLength()));
                } else
                    res.add(GridHadoopUtils.wrapSplit(i, nativeSplit, nativeSplit.getLocations()));
            }

            return res;
        } catch (IOException e) {
            throw new GridException(e);
        }
    }

    /**
     * @param clsName Input split class name.
     * @param in Input stream.
     * @param hosts Optional hosts.
     * @return File block or {@code null} if it is not a {@link FileSplit} instance.
     * @throws GridException If failed.
     */
    @Nullable
    public static GridHadoopFileBlock readFileBlock(String clsName, FSDataInputStream in, @Nullable String[] hosts)
            throws GridException {
        if (!FileSplit.class.getName().equals(clsName))
            return null;

        FileSplit split = U.newInstance(FileSplit.class);

        try {
            split.readFields(in);
        } catch (IOException e) {
            throw new GridException(e);
        }

        if (hosts == null)
            hosts = EMPTY_HOSTS;

        return new GridHadoopFileBlock(hosts, split.getPath().toUri(), split.getStart(), split.getLength());
    }
}