/**
* 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 org.apache.hadoop.hive.ql.io.parquet.read;
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.fs.Path;
import org.apache.hadoop.hive.ql.io.IOConstants;
import org.apache.hadoop.hive.ql.io.parquet.ProjectionPusher;
import org.apache.hadoop.io.ArrayWritable;
import org.apache.hadoop.io.Writable;
import org.apache.hadoop.mapred.FileSplit;
import org.apache.hadoop.mapred.InputSplit;
import org.apache.hadoop.mapred.JobConf;
import org.apache.hadoop.mapred.RecordReader;
import org.apache.hadoop.mapred.Reporter;
import org.apache.hadoop.mapreduce.TaskAttemptContext;
import org.apache.hadoop.mapreduce.TaskAttemptID;
import parquet.hadoop.ParquetFileReader;
import parquet.hadoop.ParquetInputFormat;
import parquet.hadoop.ParquetInputSplit;
import parquet.hadoop.api.ReadSupport.ReadContext;
import parquet.hadoop.metadata.BlockMetaData;
import parquet.hadoop.metadata.FileMetaData;
import parquet.hadoop.metadata.ParquetMetadata;
import parquet.hadoop.util.ContextUtil;
import parquet.schema.MessageTypeParser;
public class ParquetRecordReaderWrapper implements RecordReader<Void, ArrayWritable> {
public static final Log LOG = LogFactory.getLog(ParquetRecordReaderWrapper.class);
private final long splitLen; // for getPos()
private org.apache.hadoop.mapreduce.RecordReader<Void, ArrayWritable> realReader;
// expect readReader return same Key & Value objects (common case)
// this avoids extra serialization & deserialization of these objects
private ArrayWritable valueObj = null;
private boolean firstRecord = false;
private boolean eof = false;
private int schemaSize;
private final ProjectionPusher projectionPusher;
public ParquetRecordReaderWrapper(
final ParquetInputFormat<ArrayWritable> newInputFormat,
final InputSplit oldSplit,
final JobConf oldJobConf,
final Reporter reporter)
throws IOException, InterruptedException {
this(newInputFormat, oldSplit, oldJobConf, reporter, new ProjectionPusher());
}
public ParquetRecordReaderWrapper(
final ParquetInputFormat<ArrayWritable> newInputFormat,
final InputSplit oldSplit,
final JobConf oldJobConf,
final Reporter reporter,
final ProjectionPusher pusher)
throws IOException, InterruptedException {
this.splitLen = oldSplit.getLength();
this.projectionPusher = pusher;
final ParquetInputSplit split = getSplit(oldSplit, oldJobConf);
TaskAttemptID taskAttemptID = TaskAttemptID.forName(oldJobConf.get(IOConstants.MAPRED_TASK_ID));
if (taskAttemptID == null) {
taskAttemptID = new TaskAttemptID();
}
// create a TaskInputOutputContext
final TaskAttemptContext taskContext = ContextUtil.newTaskAttemptContext(oldJobConf, taskAttemptID);
if (split != null) {
try {
realReader = newInputFormat.createRecordReader(split, taskContext);
realReader.initialize(split, taskContext);
// read once to gain access to key and value objects
if (realReader.nextKeyValue()) {
firstRecord = true;
valueObj = realReader.getCurrentValue();
} else {
eof = true;
}
} catch (final InterruptedException e) {
throw new IOException(e);
}
} else {
realReader = null;
eof = true;
if (valueObj == null) { // Should initialize the value for createValue
valueObj = new ArrayWritable(Writable.class, new Writable[schemaSize]);
}
}
}
@Override
public void close() throws IOException {
if (realReader != null) {
realReader.close();
}
}
@Override
public Void createKey() {
return null;
}
@Override
public ArrayWritable createValue() {
return valueObj;
}
@Override
public long getPos() throws IOException {
return (long) (splitLen * getProgress());
}
@Override
public float getProgress() throws IOException {
if (realReader == null) {
return 1f;
} else {
try {
return realReader.getProgress();
} catch (final InterruptedException e) {
throw new IOException(e);
}
}
}
@Override
public boolean next(final Void key, final ArrayWritable value) throws IOException {
if (eof) {
return false;
}
try {
if (firstRecord) { // key & value are already read.
firstRecord = false;
} else if (!realReader.nextKeyValue()) {
eof = true; // strictly not required, just for consistency
return false;
}
final ArrayWritable tmpCurValue = realReader.getCurrentValue();
if (value != tmpCurValue) {
final Writable[] arrValue = value.get();
final Writable[] arrCurrent = tmpCurValue.get();
if (value != null && arrValue.length == arrCurrent.length) {
System.arraycopy(arrCurrent, 0, arrValue, 0, arrCurrent.length);
} else {
if (arrValue.length != arrCurrent.length) {
throw new IOException("DeprecatedParquetHiveInput : size of object differs. Value" +
" size : " + arrValue.length + ", Current Object size : " + arrCurrent.length);
} else {
throw new IOException("DeprecatedParquetHiveInput can not support RecordReaders that" +
" don't return same key & value & value is null");
}
}
}
return true;
} catch (final InterruptedException e) {
throw new IOException(e);
}
}
/**
* gets a ParquetInputSplit corresponding to a split given by Hive
*
* @param oldSplit The split given by Hive
* @param conf The JobConf of the Hive job
* @return a ParquetInputSplit corresponding to the oldSplit
* @throws IOException if the config cannot be enhanced or if the footer cannot be read from the file
*/
protected ParquetInputSplit getSplit(
final InputSplit oldSplit,
final JobConf conf
) throws IOException {
ParquetInputSplit split;
if (oldSplit instanceof FileSplit) {
final Path finalPath = ((FileSplit) oldSplit).getPath();
final JobConf cloneJob = projectionPusher.pushProjectionsAndFilters(conf, finalPath.getParent());
final ParquetMetadata parquetMetadata = ParquetFileReader.readFooter(cloneJob, finalPath);
final List<BlockMetaData> blocks = parquetMetadata.getBlocks();
final FileMetaData fileMetaData = parquetMetadata.getFileMetaData();
final ReadContext readContext = new DataWritableReadSupport()
.init(cloneJob, fileMetaData.getKeyValueMetaData(), fileMetaData.getSchema());
schemaSize = MessageTypeParser.parseMessageType(readContext.getReadSupportMetadata()
.get(DataWritableReadSupport.HIVE_SCHEMA_KEY)).getFieldCount();
final List<BlockMetaData> splitGroup = new ArrayList<BlockMetaData>();
final long splitStart = ((FileSplit) oldSplit).getStart();
final long splitLength = ((FileSplit) oldSplit).getLength();
for (final BlockMetaData block : blocks) {
final long firstDataPage = block.getColumns().get(0).getFirstDataPageOffset();
if (firstDataPage >= splitStart && firstDataPage < splitStart + splitLength) {
splitGroup.add(block);
}
}
if (splitGroup.isEmpty()) {
LOG.warn("Skipping split, could not find row group in: " + (FileSplit) oldSplit);
split = null;
} else {
split = new ParquetInputSplit(finalPath,
splitStart,
splitLength,
((FileSplit) oldSplit).getLocations(),
splitGroup,
readContext.getRequestedSchema().toString(),
fileMetaData.getSchema().toString(),
fileMetaData.getKeyValueMetaData(),
readContext.getReadSupportMetadata());
}
} else {
throw new IllegalArgumentException("Unknown split type: " + oldSplit);
}
return split;
}
}