com.moz.fiji.mapreduce.output.FileMapReduceJobOutput.java Source code

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Here is the source code for com.moz.fiji.mapreduce.output.FileMapReduceJobOutput.java

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/**
 * (c) Copyright 2012 WibiData, Inc.
 *
 * See the NOTICE file distributed with this work for additional
 * information regarding copyright ownership.
 *
 * 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 com.moz.fiji.mapreduce.output;

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

import org.apache.hadoop.fs.Path;
import org.apache.hadoop.mapreduce.Job;
import org.apache.hadoop.mapreduce.lib.output.FileOutputFormat;

import com.moz.fiji.annotations.ApiAudience;
import com.moz.fiji.annotations.ApiStability;
import com.moz.fiji.annotations.Inheritance;
import com.moz.fiji.mapreduce.MapReduceJobOutput;
import com.moz.fiji.mapreduce.tools.framework.JobIOConfKeys;

/** Base class for MapReduce job output types that write to files. */
@ApiAudience.Public
@ApiStability.Stable
@Inheritance.Sealed
public abstract class FileMapReduceJobOutput extends MapReduceJobOutput {

    /** The file system path for the output files. */
    private Path mFilePath;
    /** The number of output file splits. */
    private int mNumSplits;

    /** Default constructor. Do not use directly. */
    FileMapReduceJobOutput() {
    }

    /** {@inheritDoc} */
    @Override
    public void initialize(Map<String, String> params) throws IOException {
        mFilePath = new Path(params.get(JobIOConfKeys.FILE_PATH_KEY));
        mNumSplits = Integer.parseInt(params.get(JobIOConfKeys.NSPLITS_KEY));
    }

    /**
     * Creates a new <code>FileMapReduceJobOutput</code> instance.
     *
     * @param filePath The file system path for the output files.
     * @param numSplits The number of output file splits.
     */
    FileMapReduceJobOutput(Path filePath, int numSplits) {
        mFilePath = filePath;
        mNumSplits = numSplits;
    }

    /** {@inheritDoc} */
    @Override
    public void configure(Job job) throws IOException {
        super.configure(job);
        FileOutputFormat.setOutputPath(job, mFilePath);
        job.setNumReduceTasks(mNumSplits);
    }
}