org.cloudgraph.mapreduce.GraphXmlOutputFormat Maven / Gradle / Ivy

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/**
 * Copyright 2017 TerraMeta Software, Inc.
 * 
 * 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.cloudgraph.mapreduce;

import java.io.DataOutputStream;
import java.io.IOException;

import org.apache.hadoop.conf.Configurable;
import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.fs.FSDataOutputStream;
import org.apache.hadoop.fs.FileSystem;
import org.apache.hadoop.fs.Path;
import org.apache.hadoop.io.LongWritable;
import org.apache.hadoop.io.compress.CompressionCodec;
import org.apache.hadoop.io.compress.GzipCodec;
import org.apache.hadoop.mapreduce.RecordWriter;
import org.apache.hadoop.mapreduce.TaskAttemptContext;
import org.apache.hadoop.mapreduce.lib.output.FileOutputFormat;
import org.apache.hadoop.util.ReflectionUtils;

/**
 * An XML oriented output format based on FileOutputFormat
 * 
 * @see org.cloudgraph.mapreduce.GraphXmlRecordReader
 * @see org.cloudgraph.mapreduce.GraphWritable
 * 
 * @author Scott Cinnamond
 * @since 0.6.0
 */
public class GraphXmlOutputFormat extends FileOutputFormat implements
    Configurable, GraphXml {

  /** The configuration. */
  private Configuration conf = null;

  @Override
  public Configuration getConf() {
    return this.conf;
  }

  @Override
  public void setConf(Configuration configuration) {
    this.conf = configuration;
  }

  @Override
  public RecordWriter getRecordWriter(TaskAttemptContext job)
      throws IOException, InterruptedException {
    Configuration conf = job.getConfiguration();
    boolean isCompressed = getCompressOutput(job);
    CompressionCodec codec = null;
    String extension = "";
    if (isCompressed) {
      Class codecClass = getOutputCompressorClass(job, GzipCodec.class);
      codec = (CompressionCodec) ReflectionUtils.newInstance(codecClass, conf);
      extension = codec.getDefaultExtension();
    }
    Path file = getDefaultWorkFile(job, extension);
    FileSystem fs = file.getFileSystem(conf);
    if (!isCompressed) {
      FSDataOutputStream fileOut = fs.create(file, false);
      return new GraphXmlRecordWriter(fileOut, job);
    } else {
      FSDataOutputStream fileOut = fs.create(file, false);
      return new GraphXmlRecordWriter(new DataOutputStream(codec.createOutputStream(fileOut)), job);
    }
  }

}