/*
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you 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.apache.tinkerpop.gremlin.hadoop.structure.io;
import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.fs.FileSystem;
import org.apache.hadoop.fs.Path;
import org.apache.hadoop.io.NullWritable;
import org.apache.hadoop.io.compress.CompressionCodec;
import org.apache.hadoop.io.compress.DefaultCodec;
import org.apache.hadoop.mapreduce.TaskAttemptContext;
import org.apache.hadoop.mapreduce.lib.output.FileOutputFormat;
import org.apache.hadoop.util.ReflectionUtils;
import org.apache.tinkerpop.gremlin.hadoop.process.computer.PersistResultGraphAware;
import org.apache.tinkerpop.gremlin.process.computer.GraphComputer;
import java.io.DataOutputStream;
import java.io.IOException;
/**
* @author Marko A. Rodriguez (http://markorodriguez.com)
*/
public abstract class CommonFileOutputFormat extends FileOutputFormat<NullWritable, VertexWritable> implements PersistResultGraphAware {
protected DataOutputStream getDataOutputStream(final TaskAttemptContext job) throws IOException, InterruptedException {
final Configuration conf = job.getConfiguration();
boolean isCompressed = getCompressOutput(job);
CompressionCodec codec = null;
String extension = "";
if (isCompressed) {
final Class<? extends CompressionCodec> codecClass = getOutputCompressorClass(job, DefaultCodec.class);
codec = ReflectionUtils.newInstance(codecClass, conf);
extension = codec.getDefaultExtension();
}
final Path file = super.getDefaultWorkFile(job, extension);
final FileSystem fs = file.getFileSystem(conf);
if (!isCompressed) {
return new DataOutputStream(fs.create(file, false));
} else {
return new DataOutputStream(codec.createOutputStream(fs.create(file, false)));
}
}
@Override
public boolean supportsResultGraphPersistCombination(final GraphComputer.ResultGraph resultGraph, final GraphComputer.Persist persist) {
return persist.equals(GraphComputer.Persist.NOTHING) || resultGraph.equals(GraphComputer.ResultGraph.NEW);
}
}