org.apache.trevni.avro.mapreduce.AvroTrevniKeyRecordWriter.java Source code

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Here is the source code for org.apache.trevni.avro.mapreduce.AvroTrevniKeyRecordWriter.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 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());
    }
}