/** * 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 datafu.hourglass.avro; import java.io.IOException; import org.apache.avro.Schema; import org.apache.avro.mapred.AvroKey; import org.apache.avro.mapreduce.AvroKeyRecordReader; import org.apache.hadoop.io.NullWritable; 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.FileInputFormat; /** * A MapReduce InputFormat that can handle Avro container files and multiple inputs. * The input schema is determine based on the split. The mapping from input path * to schema is stored in the job configuration. * * <p>Keys are AvroKey wrapper objects that contain the Avro data. Since Avro * container files store only records (not key/value pairs), the value from * this InputFormat is a NullWritable.</p> */ public class AvroMultipleInputsKeyInputFormat<T> extends FileInputFormat<AvroKey<T>, NullWritable> { /** {@inheritDoc} */ @Override public RecordReader<AvroKey<T>, NullWritable> createRecordReader( InputSplit split, TaskAttemptContext context) throws IOException, InterruptedException { Schema readerSchema = AvroMultipleInputsUtil.getInputKeySchemaForSplit(context.getConfiguration(), split); if (readerSchema == null) { throw new RuntimeException("Could not determine input schema"); } return new AvroKeyRecordReader<T>(readerSchema); } }