org.apache.avro.mapred.AvroOutputFormat Maven / Gradle / Ivy
/**
* 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.avro.mapred;
import java.io.IOException;
import java.util.Map;
import java.net.URLDecoder;
import org.apache.hadoop.io.NullWritable;
import org.apache.hadoop.fs.FileSystem;
import org.apache.hadoop.fs.Path;
import org.apache.hadoop.mapred.JobConf;
import org.apache.hadoop.mapred.Reporter;
import org.apache.hadoop.mapred.FileOutputFormat;
import org.apache.hadoop.mapred.RecordWriter;
import org.apache.hadoop.util.Progressable;
import org.apache.avro.Schema;
import org.apache.avro.specific.SpecificDatumWriter;
import org.apache.avro.file.DataFileWriter;
import org.apache.avro.file.CodecFactory;
/** An {@link org.apache.hadoop.mapred.OutputFormat} for Avro data files. */
public class AvroOutputFormat
extends FileOutputFormat, NullWritable> {
/** The file name extension for avro data files. */
public final static String EXT = ".avro";
/** The configuration key for Avro deflate level. */
public static final String DEFLATE_LEVEL_KEY = "avro.mapred.deflate.level";
/** The default deflate level. */
public static final int DEFAULT_DEFLATE_LEVEL = 1;
/** Enable output compression using the deflate codec and specify its level.*/
public static void setDeflateLevel(JobConf job, int level) {
FileOutputFormat.setCompressOutput(job, true);
job.setInt(DEFLATE_LEVEL_KEY, level);
}
public RecordWriter, NullWritable>
getRecordWriter(FileSystem ignore, JobConf job,
String name, Progressable prog)
throws IOException {
boolean isMapOnly = job.getNumReduceTasks() == 0;
Schema schema = isMapOnly
? AvroJob.getMapOutputSchema(job)
: AvroJob.getOutputSchema(job);
final DataFileWriter writer =
new DataFileWriter(new SpecificDatumWriter());
if (FileOutputFormat.getCompressOutput(job)) {
int level = job.getInt(DEFLATE_LEVEL_KEY, DEFAULT_DEFLATE_LEVEL);
writer.setCodec(CodecFactory.deflateCodec(level));
}
// copy metadata from job
for (Map.Entry e : job) {
if (e.getKey().startsWith(AvroJob.TEXT_PREFIX))
writer.setMeta(e.getKey().substring(AvroJob.TEXT_PREFIX.length()),
e.getValue());
if (e.getKey().startsWith(AvroJob.BINARY_PREFIX))
writer.setMeta(e.getKey().substring(AvroJob.BINARY_PREFIX.length()),
URLDecoder.decode(e.getValue(), "ISO-8859-1")
.getBytes("ISO-8859-1"));
}
Path path = FileOutputFormat.getTaskOutputPath(job, name+EXT);
writer.create(schema, path.getFileSystem(job).create(path));
return new RecordWriter, NullWritable>() {
public void write(AvroWrapper wrapper, NullWritable ignore)
throws IOException {
writer.append(wrapper.datum());
}
public void close(Reporter reporter) throws IOException {
writer.close();
}
};
}
}