com.ibm.bi.dml.runtime.matrix.data.MultipleOutputCommitter.java Source code

Introduction

Here is the source code for com.ibm.bi.dml.runtime.matrix.data.MultipleOutputCommitter.java

Source

/**
 * (C) Copyright IBM Corp. 2010, 2015
 *
 * 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.ibm.bi.dml.runtime.matrix.data;

import java.io.IOException;

import org.apache.hadoop.fs.FileStatus;
import org.apache.hadoop.fs.FileSystem;
import org.apache.hadoop.fs.Path;
import org.apache.hadoop.mapred.FileOutputCommitter;
import org.apache.hadoop.mapred.FileOutputFormat;
import org.apache.hadoop.mapred.JobConf;
import org.apache.hadoop.mapred.JobContext;
import org.apache.hadoop.mapred.TaskAttemptContext;
import org.apache.hadoop.mapred.TaskAttemptID;

import com.ibm.bi.dml.runtime.matrix.mapred.MRJobConfiguration;

public class MultipleOutputCommitter extends FileOutputCommitter {

    // maintain the map of matrix index to its final output dir
    // private HashMap<Byte, String> outputmap=new HashMap<Byte, String>();
    private String[] outputs;

    @Override
    public void setupJob(JobContext context) throws IOException {
        super.setupJob(context);
        // get output file directories and create directories
        JobConf conf = context.getJobConf();
        String[] loutputs = MRJobConfiguration.getOutputs(conf);
        for (String dir : loutputs) {
            Path path = new Path(dir);
            FileSystem fs = path.getFileSystem(conf);
            if (!fs.mkdirs(path))
                LOG.error("Mkdirs failed to create " + path.toString());
        }
    }

    @Override
    public void cleanupJob(JobContext context) throws IOException {
        JobConf conf = context.getJobConf();
        // do the clean up of temporary directory
        Path outputPath = FileOutputFormat.getOutputPath(conf);
        if (outputPath != null) {
            FileSystem fs = outputPath.getFileSystem(conf);
            context.getProgressible().progress();
            if (fs.exists(outputPath))
                fs.delete(outputPath, true);
        }
    }

    @Override
    public void commitTask(TaskAttemptContext context) throws IOException {
        JobConf conf = context.getJobConf();
        TaskAttemptID attemptId = context.getTaskAttemptID();

        // get the mapping between index to output filename
        outputs = MRJobConfiguration.getOutputs(conf);

        //get temp task output path (compatible with hadoop1 and hadoop2)
        Path taskOutPath = FileOutputFormat.getWorkOutputPath(conf);
        FileSystem fs = taskOutPath.getFileSystem(conf);
        if (!fs.exists(taskOutPath))
            throw new IOException("Task output path " + taskOutPath.toString() + "does not exist.");

        // Move the task outputs to their final places
        context.getProgressible().progress();
        moveFinalTaskOutputs(context, fs, taskOutPath);

        // Delete the temporary task-specific output directory
        if (!fs.delete(taskOutPath, true))
            LOG.debug(
                    "Failed to delete the temporary output directory of task: " + attemptId + " - " + taskOutPath);
    }

    /**
     * 
     * @param context
     * @param fs
     * @param taskOutput
     * @throws IOException
     */
    private void moveFinalTaskOutputs(TaskAttemptContext context, FileSystem fs, Path taskOutput)
            throws IOException {
        context.getProgressible().progress();

        if (fs.getFileStatus(taskOutput).isDirectory()) {
            FileStatus[] files = fs.listStatus(taskOutput);
            if (files != null)
                for (FileStatus file : files) //for all files
                    if (!file.isDirectory()) //skip directories
                        moveFileToDestination(context, fs, file.getPath());
        }
    }

    /**
     * 
     * @param context
     * @param fs
     * @param file
     * @throws IOException
     */
    private void moveFileToDestination(TaskAttemptContext context, FileSystem fs, Path file) throws IOException {
        JobConf conf = context.getJobConf();
        TaskAttemptID attemptId = context.getTaskAttemptID();

        //get output index and final destination
        String taskType = (conf.getBoolean(JobContext.TASK_ISMAP, true)) ? "m" : "r";
        String name = file.getName();
        int charIx = name.indexOf("-" + taskType + "-");
        int index = Integer.parseInt(name.substring(0, charIx));
        Path finalPath = new Path(outputs[index], file.getName());

        //move file from 'file' to 'finalPath'
        if (!fs.rename(file, finalPath)) {
            if (!fs.delete(finalPath, true))
                throw new IOException("Failed to delete earlier output " + finalPath + " for rename of " + file
                        + " in task " + attemptId);
            if (!fs.rename(file, finalPath))
                throw new IOException(
                        "Failed to save output " + finalPath + " for rename of " + file + " in task: " + attemptId);
        }
    }

}