content: /**
   * 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
   *
   *     https://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.mapred.AvroKey;
  import org.apache.avro.mapred.AvroValue;
  import org.apache.hadoop.mapreduce.InputSplit;
  import org.apache.hadoop.mapreduce.RecordReader;
  import org.apache.hadoop.mapreduce.TaskAttemptContext;
  import org.apache.hadoop.mapreduce.lib.input.CombineFileInputFormat;
  import org.apache.hadoop.mapreduce.lib.input.CombineFileRecordReader;
  import org.apache.hadoop.mapreduce.lib.input.CombineFileRecordReaderWrapper;
  import org.apache.hadoop.mapreduce.lib.input.CombineFileSplit;
  
  /**
   * A combine avro keyvalue file input format that can combine small avro files
   * into mappers.
   *
   * @param <K> The type of the Avro key to read.
   * @param <V> The type of the Avro value to read.
   */
  public class CombineAvroKeyValueFileInputFormat<K, V> extends CombineFileInputFormat<AvroKey<K>, AvroValue<V>> {
  
    @Override
    public RecordReader<AvroKey<K>, AvroValue<V>> createRecordReader(InputSplit inputSplit,
        TaskAttemptContext taskAttemptContext) throws IOException {
      return new CombineFileRecordReader((CombineFileSplit) inputSplit, taskAttemptContext,
          CombineAvroKeyValueFileInputFormat.AvroKeyValueFileRecordReaderWrapper.class);
    }
  
    /**
     * A record reader that may be passed to <code>CombineFileRecordReader</code> so
     * that it can be used in a <code>CombineFileInputFormat</code>-equivalent for
     * <code>AvroKeyValueInputFormat</code>.
     *
     * @see CombineFileRecordReader
     * @see CombineFileInputFormat
     * @see AvroKeyValueInputFormat
     */
    private static class AvroKeyValueFileRecordReaderWrapper<K, V>
        extends CombineFileRecordReaderWrapper<AvroKey<K>, AvroValue<V>> {
      // this constructor signature is required by CombineFileRecordReader
      public AvroKeyValueFileRecordReaderWrapper(CombineFileSplit split, TaskAttemptContext context, Integer idx)
          throws IOException, InterruptedException {
        super(new AvroKeyValueInputFormat<>(), split, context, idx);
      }
    }
  }
  