| /** |
| * 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.hadoop.mapreduce.lib.input; |
| |
| import java.io.IOException; |
| |
| import org.apache.hadoop.classification.InterfaceAudience; |
| import org.apache.hadoop.classification.InterfaceStability; |
| import org.apache.hadoop.mapreduce.InputFormat; |
| import org.apache.hadoop.mapreduce.InputSplit; |
| import org.apache.hadoop.mapreduce.RecordReader; |
| import org.apache.hadoop.mapreduce.TaskAttemptContext; |
| import org.apache.hadoop.util.ReflectionUtils; |
| |
| /** |
| * This is a delegating RecordReader, which delegates the functionality to the |
| * underlying record reader in {@link TaggedInputSplit} |
| */ |
| @InterfaceAudience.Private |
| @InterfaceStability.Unstable |
| public class DelegatingRecordReader<K, V> extends RecordReader<K, V> { |
| RecordReader<K, V> originalRR; |
| |
| /** |
| * Constructs the DelegatingRecordReader. |
| * |
| * @param split TaggegInputSplit object |
| * @param context TaskAttemptContext object |
| * |
| * @throws IOException |
| * @throws InterruptedException |
| */ |
| @SuppressWarnings("unchecked") |
| public DelegatingRecordReader(InputSplit split, TaskAttemptContext context) |
| throws IOException, InterruptedException { |
| // Find the InputFormat and then the RecordReader from the |
| // TaggedInputSplit. |
| TaggedInputSplit taggedInputSplit = (TaggedInputSplit) split; |
| InputFormat<K, V> inputFormat = (InputFormat<K, V>) ReflectionUtils |
| .newInstance(taggedInputSplit.getInputFormatClass(), context |
| .getConfiguration()); |
| originalRR = inputFormat.createRecordReader(taggedInputSplit |
| .getInputSplit(), context); |
| } |
| |
| @Override |
| public void close() throws IOException { |
| originalRR.close(); |
| } |
| |
| @Override |
| public K getCurrentKey() throws IOException, InterruptedException { |
| return originalRR.getCurrentKey(); |
| } |
| |
| @Override |
| public V getCurrentValue() throws IOException, InterruptedException { |
| return originalRR.getCurrentValue(); |
| } |
| |
| @Override |
| public float getProgress() throws IOException, InterruptedException { |
| return originalRR.getProgress(); |
| } |
| |
| @Override |
| public void initialize(InputSplit split, TaskAttemptContext context) |
| throws IOException, InterruptedException { |
| originalRR.initialize(((TaggedInputSplit) split).getInputSplit(), context); |
| } |
| |
| @Override |
| public boolean nextKeyValue() throws IOException, InterruptedException { |
| return originalRR.nextKeyValue(); |
| } |
| |
| } |