/*
* 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.howl.mapreduce;
import java.io.IOException;
import org.apache.hadoop.io.Writable;
import org.apache.hadoop.io.WritableComparable;
import org.apache.hadoop.mapreduce.InputSplit;
import org.apache.hadoop.mapreduce.RecordReader;
import org.apache.hadoop.mapreduce.TaskAttemptContext;
import org.apache.howl.data.HowlRecord;
/** The Howl wrapper for the underlying RecordReader, this ensures that the initialize on
* the underlying record reader is done with the underlying split, not with HowlSplit.
*/
class HowlRecordReader extends RecordReader<WritableComparable, HowlRecord> {
/** The underlying record reader to delegate to. */
private final RecordReader<? extends WritableComparable, ? extends Writable> baseRecordReader;
/** The storage driver used */
private final HowlInputStorageDriver storageDriver;
/**
* Instantiates a new howl record reader.
* @param baseRecordReader the base record reader
*/
public HowlRecordReader(HowlInputStorageDriver storageDriver, RecordReader<? extends WritableComparable, ? extends Writable> baseRecordReader) {
this.baseRecordReader = baseRecordReader;
this.storageDriver = storageDriver;
}
/* (non-Javadoc)
* @see org.apache.hadoop.mapreduce.RecordReader#initialize(org.apache.hadoop.mapreduce.InputSplit, org.apache.hadoop.mapreduce.TaskAttemptContext)
*/
@Override
public void initialize(InputSplit split, TaskAttemptContext taskContext)
throws IOException, InterruptedException {
InputSplit baseSplit = split;
if( split instanceof HowlSplit ) {
baseSplit = ((HowlSplit) split).getBaseSplit();
}
baseRecordReader.initialize(baseSplit, taskContext);
}
/* (non-Javadoc)
* @see org.apache.hadoop.mapreduce.RecordReader#getCurrentKey()
*/
@Override
public WritableComparable getCurrentKey() throws IOException, InterruptedException {
return baseRecordReader.getCurrentKey();
}
/* (non-Javadoc)
* @see org.apache.hadoop.mapreduce.RecordReader#getCurrentValue()
*/
@Override
public HowlRecord getCurrentValue() throws IOException, InterruptedException {
return storageDriver.convertToHowlRecord(baseRecordReader.getCurrentKey(),baseRecordReader.getCurrentValue());
}
/* (non-Javadoc)
* @see org.apache.hadoop.mapreduce.RecordReader#getProgress()
*/
@Override
public float getProgress() throws IOException, InterruptedException {
return baseRecordReader.getProgress();
}
/* (non-Javadoc)
* @see org.apache.hadoop.mapreduce.RecordReader#nextKeyValue()
*/
@Override
public boolean nextKeyValue() throws IOException, InterruptedException {
return baseRecordReader.nextKeyValue();
}
/* (non-Javadoc)
* @see org.apache.hadoop.mapreduce.RecordReader#close()
*/
@Override
public void close() throws IOException {
baseRecordReader.close();
}
}