com.ci.backports.avro.mapreduce.AvroOutputFormat.java Source code

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Here is the source code for com.ci.backports.avro.mapreduce.AvroOutputFormat.java

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/**
 * 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 com.ci.backports.avro.mapreduce;

import java.io.IOException;

import org.apache.hadoop.io.NullWritable;
import org.apache.hadoop.fs.Path;
import org.apache.hadoop.mapreduce.Job;
import org.apache.hadoop.mapreduce.RecordWriter;
import org.apache.hadoop.mapreduce.TaskAttemptContext;
import org.apache.hadoop.mapreduce.lib.output.FileOutputFormat;

import org.apache.avro.Schema;
import org.apache.avro.file.CodecFactory;
import org.apache.avro.file.DataFileWriter;
import org.apache.avro.mapred.AvroWrapper;
import org.apache.avro.specific.SpecificDatumWriter;

/**
 * A {@link org.apache.hadoop.mapreduce.OutputFormat} for Avro container files.
 */
public class AvroOutputFormat<T> extends FileOutputFormat<AvroWrapper<T>, NullWritable> {

    /** Enable output compression using the deflate codec and specify its level.*/
    public static void setDeflateLevel(Job job, int level) {
        FileOutputFormat.setCompressOutput(job, true);
        job.getConfiguration().setInt(org.apache.avro.mapred.AvroOutputFormat.DEFLATE_LEVEL_KEY, level);
    }

    @Override
    public RecordWriter<AvroWrapper<T>, NullWritable> getRecordWriter(TaskAttemptContext context)
            throws IOException {
        Schema schema = AvroJob.getOutputSchema(context.getConfiguration());
        if (schema == null) {
            throw new RuntimeException("AvroOutputFormat requires an output schema.");
        }

        final DataFileWriter<T> writer = new DataFileWriter<T>(new SpecificDatumWriter<T>());

        if (FileOutputFormat.getCompressOutput(context)) {
            int level = context.getConfiguration().getInt(org.apache.avro.mapred.AvroOutputFormat.DEFLATE_LEVEL_KEY,
                    org.apache.avro.mapred.AvroOutputFormat.DEFAULT_DEFLATE_LEVEL);
            writer.setCodec(CodecFactory.deflateCodec(level));
        }

        Path path = getDefaultWorkFile(context, org.apache.avro.mapred.AvroOutputFormat.EXT);
        writer.create(schema, path.getFileSystem(context.getConfiguration()).create(path));

        return new RecordWriter<AvroWrapper<T>, NullWritable>() {
            public void write(AvroWrapper<T> record, NullWritable ignore) throws IOException {
                writer.append(record.datum());
            }

            public void close(TaskAttemptContext context) throws IOException {
                writer.close();
            }
        };
    }
}