/**
* 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.split;
import java.io.IOException;
import java.util.ArrayList;
import java.util.List;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.apache.hadoop.classification.InterfaceAudience.Public;
import org.apache.hadoop.classification.InterfaceStability.Evolving;
import org.apache.hadoop.conf.Configurable;
import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.mapreduce.InputFormat;
import org.apache.hadoop.mapreduce.InputSplit;
import org.apache.hadoop.mapreduce.JobContext;
import org.apache.hadoop.mapreduce.RecordReader;
import org.apache.hadoop.mapreduce.TaskAttemptContext;
import org.apache.tez.common.ReflectionUtils;
import org.apache.tez.dag.api.TezUncheckedException;
import com.google.common.base.Preconditions;
/**
* An InputFormat that provides a generic grouping around
* the splits of a real InputFormat
*/
@Public
@Evolving
public class TezGroupedSplitsInputFormat<K, V> extends InputFormat<K, V>
implements Configurable{
private static final Log LOG = LogFactory.getLog(TezGroupedSplitsInputFormat.class);
InputFormat<K, V> wrappedInputFormat;
int desiredNumSplits = 0;
Configuration conf;
public TezGroupedSplitsInputFormat() {
}
public void setInputFormat(InputFormat<K, V> wrappedInputFormat) {
this.wrappedInputFormat = wrappedInputFormat;
if (LOG.isDebugEnabled()) {
LOG.debug("wrappedInputFormat: " + wrappedInputFormat.getClass().getName());
}
}
public void setDesiredNumberOfSplits(int num) {
Preconditions.checkArgument(num >= 0);
this.desiredNumSplits = num;
if (LOG.isDebugEnabled()) {
LOG.debug("desiredNumSplits: " + desiredNumSplits);
}
}
class SplitHolder {
InputSplit split;
boolean isProcessed = false;
SplitHolder(InputSplit split) {
this.split = split;
}
}
class LocationHolder {
List<SplitHolder> splits;
int headIndex = 0;
LocationHolder(int capacity) {
splits = new ArrayList<SplitHolder>(capacity);
}
boolean isEmpty() {
return (headIndex == splits.size());
}
SplitHolder getUnprocessedHeadSplit() {
while (!isEmpty()) {
SplitHolder holder = splits.get(headIndex);
if (!holder.isProcessed) {
return holder;
}
incrementHeadIndex();
}
return null;
}
void incrementHeadIndex() {
headIndex++;
}
}
@Override
public List<InputSplit> getSplits(JobContext context) throws IOException,
InterruptedException {
List<InputSplit> originalSplits = wrappedInputFormat.getSplits(context);
TezMapReduceSplitsGrouper grouper = new TezMapReduceSplitsGrouper();
String wrappedInputFormatName = wrappedInputFormat.getClass().getName();
return grouper.getGroupedSplits(conf, originalSplits, desiredNumSplits, wrappedInputFormatName);
}
@Override
public RecordReader<K, V> createRecordReader(InputSplit split,
TaskAttemptContext context) throws IOException, InterruptedException {
TezGroupedSplit groupedSplit = (TezGroupedSplit) split;
initInputFormatFromSplit(groupedSplit);
return new TezGroupedSplitsRecordReader(groupedSplit, context);
}
@SuppressWarnings({ "rawtypes", "unchecked" })
void initInputFormatFromSplit(TezGroupedSplit split) {
if (wrappedInputFormat == null) {
Class<? extends InputFormat> clazz = (Class<? extends InputFormat>)
getClassFromName(split.wrappedInputFormatName);
try {
wrappedInputFormat = org.apache.hadoop.util.ReflectionUtils.newInstance(clazz, conf);
} catch (Exception e) {
throw new TezUncheckedException(e);
}
}
}
static Class<?> getClassFromName(String name) {
return ReflectionUtils.getClazz(name);
}
public class TezGroupedSplitsRecordReader extends RecordReader<K, V> {
TezGroupedSplit groupedSplit;
TaskAttemptContext context;
int idx = 0;
long progress;
RecordReader<K, V> curReader;
public TezGroupedSplitsRecordReader(TezGroupedSplit split,
TaskAttemptContext context) throws IOException {
this.groupedSplit = split;
this.context = context;
}
public void initialize(InputSplit split,
TaskAttemptContext context) throws IOException, InterruptedException {
if (this.groupedSplit != split) {
throw new TezUncheckedException("Splits dont match");
}
if (this.context != context) {
throw new TezUncheckedException("Contexts dont match");
}
initNextRecordReader();
}
public boolean nextKeyValue() throws IOException, InterruptedException {
while ((curReader == null) || !curReader.nextKeyValue()) {
// false return finishes. true return loops back for nextKeyValue()
if (!initNextRecordReader()) {
return false;
}
}
return true;
}
public K getCurrentKey() throws IOException, InterruptedException {
return curReader.getCurrentKey();
}
public V getCurrentValue() throws IOException, InterruptedException {
return curReader.getCurrentValue();
}
public void close() throws IOException {
if (curReader != null) {
curReader.close();
curReader = null;
}
}
protected boolean initNextRecordReader() throws IOException {
if (curReader != null) {
curReader.close();
curReader = null;
if (idx > 0) {
try {
progress += groupedSplit.wrappedSplits.get(idx-1).getLength();
} catch (InterruptedException e) {
throw new TezUncheckedException(e);
}
}
}
// if all chunks have been processed, nothing more to do.
if (idx == groupedSplit.wrappedSplits.size()) {
return false;
}
// get a record reader for the idx-th chunk
try {
curReader = wrappedInputFormat.createRecordReader(
groupedSplit.wrappedSplits.get(idx), context);
curReader.initialize(groupedSplit.wrappedSplits.get(idx), context);
} catch (Exception e) {
throw new RuntimeException (e);
}
idx++;
return true;
}
/**
* return progress based on the amount of data processed so far.
*/
public float getProgress() throws IOException, InterruptedException {
long subprogress = 0; // bytes processed in current split
if (null != curReader) {
// idx is always one past the current subsplit's true index.
subprogress = (long) (curReader.getProgress() * groupedSplit.wrappedSplits
.get(idx - 1).getLength());
}
return Math.min(1.0f, (progress + subprogress)/(float)(groupedSplit.getLength()));
}
}
@Override
public void setConf(Configuration conf) {
this.conf = conf;
}
@Override
public Configuration getConf() {
return conf;
}
}