/**
* Copyright 2011-2014 Asakusa Framework Team.
*
* Licensed 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 com.asakusafw.runtime.stage.input;
import java.io.IOException;
import java.util.Iterator;
import java.util.List;
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;
import com.asakusafw.runtime.stage.input.StageInputSplit.Source;
/**
* {@link StageInputSplit}を処理する{@link RecordReader}の実装。
* @since 0.1.0
* @version 0.2.6
*/
@SuppressWarnings("rawtypes")
public class StageInputRecordReader extends RecordReader {
private static final RecordReader<?, ?> VOID = new RecordReader<Object, Object>() {
@Override
public void initialize(InputSplit split, TaskAttemptContext ctxt) {
return;
}
@Override
public boolean nextKeyValue() {
return false;
}
@Override
public Object getCurrentKey() {
throw new IllegalStateException();
}
@Override
public Object getCurrentValue() {
throw new IllegalStateException();
}
@Override
public float getProgress() {
return 0f;
}
@Override
public void close() {
return;
}
};
private Iterator<Source> sources;
private TaskAttemptContext context;
private RecordReader<?, ?> current;
private boolean eof;
private float progressPerSource;
private float baseProgress;
@Override
public void initialize(
InputSplit split,
TaskAttemptContext taskContext) throws IOException, InterruptedException {
assert split instanceof StageInputSplit;
List<Source> sourceList = ((StageInputSplit) split).getSources();
this.sources = sourceList.iterator();
this.context = taskContext;
this.progressPerSource = sourceList.isEmpty() ? 1f : 1f / sourceList.size();
this.baseProgress = 0f;
prepare();
}
private void prepare() throws IOException, InterruptedException {
if (current != null) {
baseProgress += progressPerSource;
current.close();
}
if (sources.hasNext()) {
Source next = sources.next();
InputFormat<?, ?> format = ReflectionUtils.newInstance(next.getFormatClass(), context.getConfiguration());
current = format.createRecordReader(next.getSplit(), context);
current.initialize(next.getSplit(), context);
} else {
eof = true;
current = VOID;
}
}
@Override
public boolean nextKeyValue() throws IOException, InterruptedException {
while (eof == false) {
if (current.nextKeyValue()) {
return true;
}
prepare();
}
return false;
}
@Override
public Object getCurrentKey() throws IOException, InterruptedException {
return current.getCurrentKey();
}
@Override
public Object getCurrentValue() throws IOException, InterruptedException {
return current.getCurrentValue();
}
@Override
public float getProgress() throws IOException, InterruptedException {
float progress = current.getProgress();
return baseProgress + progress * progressPerSource;
}
@Override
public void close() throws IOException {
if (current != null) {
current.close();
}
}
}