/**
* 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.trevni.avro.mapreduce;
import java.io.IOException;
import org.apache.avro.Schema;
import org.apache.avro.mapred.AvroKey;
import org.apache.avro.mapreduce.AvroJob;
import org.apache.hadoop.io.NullWritable;
import org.apache.hadoop.mapreduce.TaskAttemptContext;
/**
* Writes Trevni records to an Trevni container file output stream.
*
* @param <T> The Java type of the Trevni data to write.
*/
public class AvroTrevniKeyRecordWriter<T> extends AvroTrevniRecordWriterBase<AvroKey<T>, NullWritable, T> {
/**
* Constructor.
* @param context The TaskAttempContext to supply the writer with information form the job configuration
*/
public AvroTrevniKeyRecordWriter(TaskAttemptContext context)
throws IOException {
super(context);
}
/** {@inheritDoc} */
@Override
public void write(AvroKey<T> key, NullWritable value) throws IOException,
InterruptedException {
writer.write(key.datum());
if (writer.sizeEstimate() >= blockSize) // block full
flush();
}
/** {@inheritDoc} */
@Override
protected Schema initSchema(TaskAttemptContext context) {
boolean isMapOnly = context.getNumReduceTasks() == 0;
return isMapOnly ? AvroJob.getMapOutputKeySchema(context
.getConfiguration()) : AvroJob.getOutputKeySchema(context
.getConfiguration());
}
}