/**
* 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.hive.ql.exec.persistence;
import java.io.IOException;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import java.util.Properties;
import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.fs.FileSystem;
import org.apache.hadoop.fs.Path;
import org.apache.hadoop.hive.ql.exec.Utilities;
import org.apache.hadoop.hive.ql.io.FSRecordWriter;
import org.apache.hadoop.hive.ql.io.HiveSequenceFileOutputFormat;
import org.apache.hadoop.hive.ql.metadata.HiveException;
import org.apache.hadoop.hive.ql.plan.PTFDeserializer;
import org.apache.hadoop.hive.ql.plan.TableDesc;
import org.apache.hadoop.hive.serde.serdeConstants;
import org.apache.hadoop.hive.serde2.lazybinary.LazyBinarySerDe;
import org.apache.hadoop.hive.serde2.objectinspector.StructObjectInspector;
import org.apache.hadoop.io.BytesWritable;
import org.apache.hadoop.io.SequenceFile;
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.Reporter;
import org.apache.hadoop.mapred.SequenceFileInputFormat;
import org.apache.hadoop.mapred.SequenceFileRecordReader;
import org.apache.hadoop.util.Progressable;
/**
* Extends the RowContainer functionality to provide random access <code>getAt(i)</code>.
* It extends RowContainer behavior in the following ways:
* <ol>
* <li> You must continue to call <b>first</b> to signal the transition from writing to the
* Container to reading from it.
* <li> As rows are being added, positions at which a <i>spill</i> occurs is captured as a
* BlockInfo object. At this point it captures the offset in the File at which the current
* Block will be written.
* <li> When first is called: we associate with each BlockInfo the File Split that it
* occurs in.
* <li> So in order to read a random row from the Container we do the following:
* <ul>
* <li> Convert the row index into a block number. This is easy because all blocks are
* the same size, given by the <code>blockSize</code>
* <li> The corresponding BlockInfo tells us the Split that this block starts in. Also
* by looking at the next Block in the BlockInfos list, we know which Split this block ends in.
* <li> So we arrange to read all the Splits that contain rows for this block. For the first
* Split we seek to the startOffset that we captured in BlockInfo.
* <li> So after reading the Splits, all rows in this block are in the 'currentReadBlock'
* </ul>
* <li> We track the span of the currentReadBlock, using
* <code>currentReadBlockStartRow,blockSize</code>. So if a row is requested in this span,
* we don't need to read rows from disk.
* <li> If the requested row is in the 'last' block; we point the currentReadBlock to
* the currentWriteBlock; the same as what RowContainer does.
* <li> the <code>getAt</code> leaves the Container in the same state as a
* <code>next</code> call; so a getAt and next calls can be interspersed.
* </ol>
*/
public class PTFRowContainer<Row extends List<Object>> extends RowContainer<Row> {
ArrayList<BlockInfo> blockInfos;
int currentReadBlockStartRow;
public PTFRowContainer(int bs, Configuration jc, Reporter reporter
) throws HiveException {
super(bs, jc, reporter);
blockInfos = new ArrayList<PTFRowContainer.BlockInfo>();
}
@Override
public void addRow(Row t) throws HiveException {
if ( willSpill() ) {
setupWriter();
PTFRecordWriter rw = (PTFRecordWriter) getRecordWriter();
BlockInfo blkInfo = new BlockInfo();
try {
blkInfo.startOffset = rw.outStream.getLength();
blockInfos.add(blkInfo);
} catch(IOException e) {
clearRows();
LOG.error(e.toString(), e);
throw new HiveException(e);
}
}
super.addRow(t);
}
@Override
public Row first() throws HiveException {
Row r = super.first();
if ( blockInfos.size() > 0 ) {
InputSplit[] inputSplits = getInputSplits();
FileSplit fS = null;
BlockInfo bI = blockInfos.get(0);
bI.startingSplit = 0;
int i = 1;
bI = i < blockInfos.size() ? blockInfos.get(i) : null;
for(int j=1; j < inputSplits.length && bI != null; j++) {
fS = (FileSplit) inputSplits[j];
while (bI != null && bI.startOffset < fS.getStart() ) {
bI.startingSplit = j - 1;
i++;
bI = i < blockInfos.size() ? blockInfos.get(i) : null;
}
}
while ( i < blockInfos.size() ) {
bI = blockInfos.get(i);
bI.startingSplit = inputSplits.length - 1;
i++;
}
}
currentReadBlockStartRow = 0;
return r;
}
@Override
public Row next() throws HiveException {
boolean endOfCurrBlock = endOfCurrentReadBlock();
if ( endOfCurrBlock ) {
currentReadBlockStartRow += getCurrentReadBlockSize();
}
return super.next();
}
@Override
public void clearRows() throws HiveException {
super.clearRows();
resetReadBlocks();
blockInfos = new ArrayList<PTFRowContainer.BlockInfo>();
}
@Override
public void close() throws HiveException {
super.close();
blockInfos = null;
}
public Row getAt(int rowIdx) throws HiveException {
int blockSize = getBlockSize();
if ( rowIdx < currentReadBlockStartRow || rowIdx >= currentReadBlockStartRow + blockSize ) {
readBlock(getBlockNum(rowIdx));
}
return getReadBlockRow(rowIdx - currentReadBlockStartRow);
}
private int numBlocks() {
return blockInfos.size() + 1;
}
private int getBlockNum(int rowIdx) {
int blockSize = getBlockSize();
return rowIdx / blockSize;
}
private void readBlock(int blockNum) throws HiveException {
currentReadBlockStartRow = getBlockSize() * blockNum;
if ( blockNum == numBlocks() - 1 ) {
setWriteBlockAsReadBlock();
return;
}
resetCurrentReadBlockToFirstReadBlock();
BlockInfo bI = blockInfos.get(blockNum);
int startSplit = bI.startingSplit;
int endSplit = startSplit;
if ( blockNum != blockInfos.size() - 1) {
endSplit = blockInfos.get(blockNum+1).startingSplit;
}
try {
int readIntoOffset = 0;
for(int i = startSplit; i <= endSplit; i++ ) {
org.apache.hadoop.mapred.RecordReader rr = setReaderAtSplit(i);
if ( i == startSplit ) {
((PTFSequenceFileRecordReader)rr).seek(bI.startOffset);
}
nextBlock(readIntoOffset);
readIntoOffset = getCurrentReadBlockSize();
}
} catch(Exception e) {
clearRows();
LOG.error(e.toString(), e);
if ( e instanceof HiveException ) {
throw (HiveException) e;
}
throw new HiveException(e);
}
}
private static class BlockInfo {
// position in file where the first row in this block starts
long startOffset;
// inputSplitNum that contains the first row in this block.
int startingSplit;
}
public static TableDesc createTableDesc(StructObjectInspector oI) {
Map<String,String> props = new HashMap<String,String>();
PTFDeserializer.addOIPropertiestoSerDePropsMap(oI, props);
String colNames = props.get(serdeConstants.LIST_COLUMNS);
String colTypes = props.get(serdeConstants.LIST_COLUMN_TYPES);
TableDesc tblDesc = new TableDesc(
PTFSequenceFileInputFormat.class, PTFHiveSequenceFileOutputFormat.class,
Utilities.makeProperties(
serdeConstants.SERIALIZATION_FORMAT, ""+ Utilities.ctrlaCode,
serdeConstants.LIST_COLUMNS, colNames.toString(),
serdeConstants.LIST_COLUMN_TYPES,colTypes.toString(),
serdeConstants.SERIALIZATION_LIB,LazyBinarySerDe.class.getName()));
return tblDesc;
}
private static class PTFRecordWriter implements FSRecordWriter {
BytesWritable EMPTY_KEY = new BytesWritable();
SequenceFile.Writer outStream;
public PTFRecordWriter(SequenceFile.Writer outStream) {
this.outStream = outStream;
}
public void write(Writable r) throws IOException {
outStream.append(EMPTY_KEY, r);
}
public void close(boolean abort) throws IOException {
outStream.close();
}
}
public static class PTFHiveSequenceFileOutputFormat<K,V>
extends HiveSequenceFileOutputFormat<K,V> {
@Override
public FSRecordWriter getHiveRecordWriter(JobConf jc, Path finalOutPath,
Class<? extends Writable> valueClass, boolean isCompressed,
Properties tableProperties, Progressable progress) throws IOException {
FileSystem fs = finalOutPath.getFileSystem(jc);
final SequenceFile.Writer outStream = Utilities.createSequenceWriter(jc,
fs, finalOutPath, BytesWritable.class, valueClass, isCompressed);
return new PTFRecordWriter(outStream);
}
}
public static class PTFSequenceFileInputFormat<K, V> extends SequenceFileInputFormat<K, V> {
public PTFSequenceFileInputFormat() {
super();
}
@Override
public org.apache.hadoop.mapred.RecordReader<K, V> getRecordReader(InputSplit split,
JobConf job, Reporter reporter)
throws IOException {
reporter.setStatus(split.toString());
return new PTFSequenceFileRecordReader<K, V>(job, (FileSplit) split);
}
}
public static class PTFSequenceFileRecordReader<K,V> extends SequenceFileRecordReader<K, V> {
public PTFSequenceFileRecordReader(Configuration conf, FileSplit split)
throws IOException {
super(conf, split);
}
@Override
public void seek(long pos) throws IOException {
super.seek(pos);
}
}
}