com.ibm.jaql.io.hadoop.DirectFileOutputCommiter.java Source code

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Here is the source code for com.ibm.jaql.io.hadoop.DirectFileOutputCommiter.java

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/*
 * Copyright (C) IBM Corp. 2010.
 * 
 * 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.jaql.io.hadoop;

import java.io.IOException;

import org.apache.hadoop.fs.FileSystem;
import org.apache.hadoop.fs.Path;
import org.apache.hadoop.mapred.FileOutputFormat;
import org.apache.hadoop.mapred.JobConf;
import org.apache.hadoop.mapred.JobContext;
import org.apache.hadoop.mapred.OutputCommitter;
import org.apache.hadoop.mapred.TaskAttemptContext;

/**
 * A OutputCommitter that works with FileOutputFormats in sequential mode.
 * It avoids extra directories and file moves of the standard FileOutputCommitter.
 */
public class DirectFileOutputCommiter extends OutputCommitter {
    @Override
    public void setupJob(JobContext context) throws IOException {
        // Create the path to the file, if needed.
        JobConf conf = context.getJobConf();
        Path outputPath = FileOutputFormat.getOutputPath(conf);
        if (outputPath != null) {
            Path tmpDir = outputPath.getParent();
            FileSystem fileSys = outputPath.getFileSystem(conf);
            if (!fileSys.mkdirs(outputPath.getParent())) {
                throw new IOException("Mkdirs failed to create " + tmpDir.toString());
            }
        }
    }

    @Override
    public void cleanupJob(JobContext context) throws IOException {
    }

    @Override
    public void setupTask(TaskAttemptContext context) throws IOException {
    }

    @Override
    public boolean needsTaskCommit(TaskAttemptContext context) throws IOException {
        return false;
    }

    @Override
    public void commitTask(TaskAttemptContext context) throws IOException {
        // Nothing to do becuase we wrote directly to the file.
    }

    @Override
    public void abortTask(TaskAttemptContext context) throws IOException {
        Path outputPath = FileOutputFormat.getOutputPath(context.getJobConf());
        // TODO: LOG.warn("partial write of "+outputPath+"  What should we do with partial output when writing directly?");
        //    Path taskOutputPath =  getTempTaskOutputPath(context);
        //    try {
        //      if (taskOutputPath != null) {
        //        FileSystem fs = taskOutputPath.getFileSystem(context.getJobConf());
        //        context.getProgressible().progress();
        //        fs.delete(taskOutputPath, true);
        //      }
        //    } catch (IOException ie) {
        //      LOG.warn("Error discarding output" + StringUtils.stringifyException(ie));
        //    }
    }
}