org.apache.avro.mapreduce.AvroKeyRecordReader.java Source code

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Here is the source code for org.apache.avro.mapreduce.AvroKeyRecordReader.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.avro.mapreduce;

import java.io.IOException;

import org.apache.avro.Schema;
import org.apache.avro.mapred.AvroKey;
import org.apache.hadoop.io.NullWritable;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

/**
 * Reads records from an input split representing a chunk of an Avro container file.
 *
 * @param <T> The (java) type of data in Avro container file.
 */
public class AvroKeyRecordReader<T> extends AvroRecordReaderBase<AvroKey<T>, NullWritable, T> {
    private static final Logger LOG = LoggerFactory.getLogger(AvroKeyRecordReader.class);

    /** A reusable object to hold records of the Avro container file. */
    private final AvroKey<T> mCurrentRecord;

    /**
     * Constructor.
     *
     * @param readerSchema The reader schema to use for the records in the Avro container file.
     */
    public AvroKeyRecordReader(Schema readerSchema) {
        super(readerSchema);
        mCurrentRecord = new AvroKey<T>(null);
    }

    /** {@inheritDoc} */
    @Override
    public boolean nextKeyValue() throws IOException, InterruptedException {
        boolean hasNext = super.nextKeyValue();
        mCurrentRecord.datum(getCurrentRecord());
        return hasNext;
    }

    /** {@inheritDoc} */
    @Override
    public AvroKey<T> getCurrentKey() throws IOException, InterruptedException {
        return mCurrentRecord;
    }

    /** {@inheritDoc} */
    @Override
    public NullWritable getCurrentValue() throws IOException, InterruptedException {
        return NullWritable.get();
    }
}