org.apache.hadoop.hive.ql.exec.FetchOperator Maven / Gradle / Ivy
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* 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;
import java.io.IOException;
import java.io.Serializable;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.HashMap;
import java.util.Iterator;
import java.util.List;
import java.util.Map;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.fs.FileStatus;
import org.apache.hadoop.fs.FileSystem;
import org.apache.hadoop.fs.Path;
import org.apache.hadoop.hive.common.FileUtils;
import org.apache.hadoop.hive.conf.HiveConf;
import org.apache.hadoop.hive.ql.io.HiveContextAwareRecordReader;
import org.apache.hadoop.hive.ql.io.HiveInputFormat;
import org.apache.hadoop.hive.ql.io.HiveRecordReader;
import org.apache.hadoop.hive.ql.metadata.HiveException;
import org.apache.hadoop.hive.ql.metadata.VirtualColumn;
import org.apache.hadoop.hive.ql.parse.SplitSample;
import org.apache.hadoop.hive.ql.plan.FetchWork;
import org.apache.hadoop.hive.ql.plan.PartitionDesc;
import org.apache.hadoop.hive.ql.plan.TableDesc;
import org.apache.hadoop.hive.ql.session.SessionState.LogHelper;
import org.apache.hadoop.hive.serde2.Deserializer;
import org.apache.hadoop.hive.serde2.SerDeException;
import org.apache.hadoop.hive.serde2.objectinspector.DelegatedObjectInspectorFactory;
import org.apache.hadoop.hive.serde2.objectinspector.InspectableObject;
import org.apache.hadoop.hive.serde2.objectinspector.ObjectInspector;
import org.apache.hadoop.hive.serde2.objectinspector.ObjectInspectorConverters;
import org.apache.hadoop.hive.serde2.objectinspector.ObjectInspectorConverters.Converter;
import org.apache.hadoop.hive.serde2.objectinspector.ObjectInspectorFactory;
import org.apache.hadoop.hive.serde2.objectinspector.StructObjectInspector;
import org.apache.hadoop.hive.serde2.objectinspector.primitive.PrimitiveObjectInspectorFactory;
import org.apache.hadoop.io.Writable;
import org.apache.hadoop.io.WritableComparable;
import org.apache.hadoop.mapred.InputFormat;
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.util.ReflectionUtils;
/**
* FetchTask implementation.
**/
public class FetchOperator implements Serializable {
static Log LOG = LogFactory.getLog(FetchOperator.class.getName());
static LogHelper console = new LogHelper(LOG);
private boolean isNativeTable;
private FetchWork work;
private Operator operator; // operator tree for processing row further (option)
private int splitNum;
private PartitionDesc currPart;
private TableDesc currTbl;
private boolean tblDataDone;
private boolean hasVC;
private boolean isPartitioned;
private StructObjectInspector vcsOI;
private List vcCols;
private ExecMapperContext context;
private transient RecordReader currRecReader;
private transient FetchInputFormatSplit[] inputSplits;
private transient InputFormat inputFormat;
private transient JobConf job;
private transient WritableComparable key;
private transient Writable value;
private transient Writable[] vcValues;
private transient Deserializer serde;
private transient Deserializer tblSerde;
private transient Converter partTblObjectInspectorConverter;
private transient Iterator iterPath;
private transient Iterator iterPartDesc;
private transient Path currPath;
private transient StructObjectInspector objectInspector;
private transient StructObjectInspector rowObjectInspector;
private transient ObjectInspector partitionedTableOI;
private transient Object[] row;
public FetchOperator() {
}
public FetchOperator(FetchWork work, JobConf job) {
this.job = job;
this.work = work;
initialize();
}
public FetchOperator(FetchWork work, JobConf job, Operator operator,
List vcCols) {
this.job = job;
this.work = work;
this.operator = operator;
this.vcCols = vcCols;
initialize();
}
private void initialize() {
if (hasVC = vcCols != null && !vcCols.isEmpty()) {
List names = new ArrayList(vcCols.size());
List inspectors = new ArrayList(vcCols.size());
for (VirtualColumn vc : vcCols) {
inspectors.add(PrimitiveObjectInspectorFactory.getPrimitiveWritableObjectInspector(
vc.getTypeInfo().getPrimitiveCategory()));
names.add(vc.getName());
}
vcsOI = ObjectInspectorFactory.getStandardStructObjectInspector(names, inspectors);
vcValues = new Writable[vcCols.size()];
}
isPartitioned = work.isPartitioned();
tblDataDone = false;
if (hasVC && isPartitioned) {
row = new Object[3];
} else if (hasVC || isPartitioned) {
row = new Object[2];
} else {
row = new Object[1];
}
if (work.getTblDesc() != null) {
isNativeTable = !work.getTblDesc().isNonNative();
} else {
isNativeTable = true;
}
setupExecContext();
}
private void setupExecContext() {
if (hasVC || work.getSplitSample() != null) {
context = new ExecMapperContext();
if (operator != null) {
operator.setExecContext(context);
}
}
}
public FetchWork getWork() {
return work;
}
public void setWork(FetchWork work) {
this.work = work;
}
public int getSplitNum() {
return splitNum;
}
public void setSplitNum(int splitNum) {
this.splitNum = splitNum;
}
public PartitionDesc getCurrPart() {
return currPart;
}
public void setCurrPart(PartitionDesc currPart) {
this.currPart = currPart;
}
public TableDesc getCurrTbl() {
return currTbl;
}
public void setCurrTbl(TableDesc currTbl) {
this.currTbl = currTbl;
}
public boolean isTblDataDone() {
return tblDataDone;
}
public void setTblDataDone(boolean tblDataDone) {
this.tblDataDone = tblDataDone;
}
public boolean isEmptyTable() {
return work.getTblDir() == null && (work.getPartDir() == null || work.getPartDir().isEmpty());
}
/**
* A cache of InputFormat instances.
*/
private static Map> inputFormats = new HashMap>();
@SuppressWarnings("unchecked")
static InputFormat getInputFormatFromCache(Class inputFormatClass,
Configuration conf) throws IOException {
if (!inputFormats.containsKey(inputFormatClass)) {
try {
InputFormat newInstance = (InputFormat) ReflectionUtils
.newInstance(inputFormatClass, conf);
inputFormats.put(inputFormatClass, newInstance);
} catch (Exception e) {
throw new IOException("Cannot create an instance of InputFormat class "
+ inputFormatClass.getName() + " as specified in mapredWork!", e);
}
}
return inputFormats.get(inputFormatClass);
}
private StructObjectInspector getRowInspectorFromTable(TableDesc table) throws Exception {
Deserializer serde = table.getDeserializerClass().newInstance();
serde.initialize(job, table.getProperties());
return createRowInspector(getStructOIFrom(serde.getObjectInspector()));
}
private StructObjectInspector getRowInspectorFromPartition(PartitionDesc partition,
ObjectInspector partitionOI) throws Exception {
String pcols = partition.getTableDesc().getProperties().getProperty(
org.apache.hadoop.hive.metastore.api.hive_metastoreConstants.META_TABLE_PARTITION_COLUMNS);
String[] partKeys = pcols.trim().split("/");
row[1] = createPartValue(partKeys, partition.getPartSpec());
return createRowInspector(getStructOIFrom(partitionOI), partKeys);
}
private StructObjectInspector getRowInspectorFromPartitionedTable(TableDesc table)
throws Exception {
Deserializer serde = table.getDeserializerClass().newInstance();
serde.initialize(job, table.getProperties());
String pcols = table.getProperties().getProperty(
org.apache.hadoop.hive.metastore.api.hive_metastoreConstants.META_TABLE_PARTITION_COLUMNS);
String[] partKeys = pcols.trim().split("/");
row[1] = null;
return createRowInspector(getStructOIFrom(serde.getObjectInspector()), partKeys);
}
private StructObjectInspector getStructOIFrom(ObjectInspector current) throws SerDeException {
if (objectInspector != null) {
current = DelegatedObjectInspectorFactory.reset(objectInspector, current);
} else {
current = DelegatedObjectInspectorFactory.wrap(current);
}
return objectInspector = (StructObjectInspector) current;
}
private StructObjectInspector createRowInspector(StructObjectInspector current)
throws SerDeException {
return hasVC ? ObjectInspectorFactory.getUnionStructObjectInspector(
Arrays.asList(current, vcsOI)) : current;
}
private StructObjectInspector createRowInspector(StructObjectInspector current, String[] partKeys)
throws SerDeException {
List partNames = new ArrayList();
List partObjectInspectors = new ArrayList();
for (String key : partKeys) {
partNames.add(key);
partObjectInspectors.add(PrimitiveObjectInspectorFactory.javaStringObjectInspector);
}
StructObjectInspector partObjectInspector = ObjectInspectorFactory
.getStandardStructObjectInspector(partNames, partObjectInspectors);
return ObjectInspectorFactory.getUnionStructObjectInspector(
hasVC ? Arrays.asList(current, partObjectInspector, vcsOI) :
Arrays.asList(current, partObjectInspector));
}
private List createPartValue(String[] partKeys, Map partSpec) {
List partValues = new ArrayList();
for (String key : partKeys) {
partValues.add(partSpec.get(key));
}
return partValues;
}
private void getNextPath() throws Exception {
// first time
if (iterPath == null) {
if (work.isNotPartitioned()) {
if (!tblDataDone) {
currPath = work.getTblDirPath();
currTbl = work.getTblDesc();
if (isNativeTable) {
FileSystem fs = currPath.getFileSystem(job);
if (fs.exists(currPath)) {
FileStatus[] fStats = listStatusUnderPath(fs, currPath);
for (FileStatus fStat : fStats) {
if (fStat.getLen() > 0) {
tblDataDone = true;
break;
}
}
}
} else {
tblDataDone = true;
}
if (!tblDataDone) {
currPath = null;
}
return;
} else {
currTbl = null;
currPath = null;
}
return;
} else {
iterPath = FetchWork.convertStringToPathArray(work.getPartDir()).iterator();
iterPartDesc = work.getPartDesc().iterator();
}
}
while (iterPath.hasNext()) {
Path nxt = iterPath.next();
PartitionDesc prt = null;
if (iterPartDesc != null) {
prt = iterPartDesc.next();
}
FileSystem fs = nxt.getFileSystem(job);
if (fs.exists(nxt)) {
FileStatus[] fStats = listStatusUnderPath(fs, nxt);
for (FileStatus fStat : fStats) {
if (fStat.getLen() > 0) {
currPath = nxt;
if (iterPartDesc != null) {
currPart = prt;
}
return;
}
}
}
}
}
private RecordReader getRecordReader() throws Exception {
if (currPath == null) {
getNextPath();
if (currPath == null) {
return null;
}
// not using FileInputFormat.setInputPaths() here because it forces a
// connection
// to the default file system - which may or may not be online during pure
// metadata
// operations
job.set("mapred.input.dir", org.apache.hadoop.util.StringUtils.escapeString(currPath
.toString()));
PartitionDesc partDesc;
if (currTbl == null) {
partDesc = currPart;
} else {
partDesc = new PartitionDesc(currTbl, null);
}
Class formatter = partDesc.getInputFileFormatClass();
inputFormat = getInputFormatFromCache(formatter, job);
Utilities.copyTableJobPropertiesToConf(partDesc.getTableDesc(), job);
InputSplit[] splits = inputFormat.getSplits(job, 1);
FetchInputFormatSplit[] inputSplits = new FetchInputFormatSplit[splits.length];
for (int i = 0; i < splits.length; i++) {
inputSplits[i] = new FetchInputFormatSplit(splits[i], formatter.getName());
}
if (work.getSplitSample() != null) {
inputSplits = splitSampling(work.getSplitSample(), inputSplits);
}
this.inputSplits = inputSplits;
splitNum = 0;
serde = partDesc.getDeserializerClass().newInstance();
serde.initialize(job, partDesc.getProperties());
if (currTbl != null) {
tblSerde = serde;
}
else {
tblSerde = currPart.getTableDesc().getDeserializerClass().newInstance();
tblSerde.initialize(job, currPart.getTableDesc().getProperties());
}
ObjectInspector outputOI = ObjectInspectorConverters.getConvertedOI(
serde.getObjectInspector(),
partitionedTableOI == null ? tblSerde.getObjectInspector() : partitionedTableOI);
partTblObjectInspectorConverter = ObjectInspectorConverters.getConverter(
serde.getObjectInspector(), outputOI);
if (LOG.isDebugEnabled()) {
LOG.debug("Creating fetchTask with deserializer typeinfo: "
+ serde.getObjectInspector().getTypeName());
LOG.debug("deserializer properties: " + partDesc.getProperties());
}
if (currPart != null) {
getRowInspectorFromPartition(currPart, outputOI);
}
}
if (splitNum >= inputSplits.length) {
if (currRecReader != null) {
currRecReader.close();
currRecReader = null;
}
currPath = null;
return getRecordReader();
}
final FetchInputFormatSplit target = inputSplits[splitNum];
@SuppressWarnings("unchecked")
final RecordReader reader =
inputFormat.getRecordReader(target.getInputSplit(), job, Reporter.NULL);
if (hasVC || work.getSplitSample() != null) {
currRecReader = new HiveRecordReader(reader, job) {
@Override
public boolean doNext(WritableComparable key, Writable value) throws IOException {
// if current pos is larger than shrinkedLength which is calculated for
// each split by table sampling, stop fetching any more (early exit)
if (target.shrinkedLength > 0 &&
context.getIoCxt().getCurrentBlockStart() > target.shrinkedLength) {
return false;
}
return super.doNext(key, value);
}
};
((HiveContextAwareRecordReader)currRecReader).
initIOContext(target, job, inputFormat.getClass(), reader);
} else {
currRecReader = reader;
}
splitNum++;
key = currRecReader.createKey();
value = currRecReader.createValue();
return currRecReader;
}
private FetchInputFormatSplit[] splitSampling(SplitSample splitSample,
FetchInputFormatSplit[] splits) {
long totalSize = 0;
for (FetchInputFormatSplit split: splits) {
totalSize += split.getLength();
}
List result = new ArrayList();
long targetSize = splitSample.getTargetSize(totalSize);
int startIndex = splitSample.getSeedNum() % splits.length;
long size = 0;
for (int i = 0; i < splits.length; i++) {
FetchInputFormatSplit split = splits[(startIndex + i) % splits.length];
result.add(split);
long splitgLength = split.getLength();
if (size + splitgLength >= targetSize) {
if (size + splitgLength > targetSize) {
split.shrinkedLength = targetSize - size;
}
break;
}
size += splitgLength;
}
return result.toArray(new FetchInputFormatSplit[result.size()]);
}
/**
* Get the next row and push down it to operator tree.
* Currently only used by FetchTask.
**/
public boolean pushRow() throws IOException, HiveException {
InspectableObject row = getNextRow();
if (row != null) {
operator.process(row.o, 0);
}
return row != null;
}
private transient final InspectableObject inspectable = new InspectableObject();
/**
* Get the next row. The fetch context is modified appropriately.
*
**/
public InspectableObject getNextRow() throws IOException {
try {
while (true) {
if (context != null) {
context.resetRow();
}
if (currRecReader == null) {
currRecReader = getRecordReader();
if (currRecReader == null) {
return null;
}
}
boolean ret = currRecReader.next(key, value);
if (ret) {
if (operator != null && context != null && context.inputFileChanged()) {
// The child operators cleanup if input file has changed
try {
operator.cleanUpInputFileChanged();
} catch (HiveException e) {
throw new IOException(e);
}
}
if (hasVC) {
vcValues = MapOperator.populateVirtualColumnValues(context, vcCols, vcValues, serde);
row[isPartitioned ? 2 : 1] = vcValues;
}
row[0] = partTblObjectInspectorConverter.convert(serde.deserialize(value));
if (hasVC || isPartitioned) {
inspectable.o = row;
inspectable.oi = rowObjectInspector;
return inspectable;
}
inspectable.o = row[0];
inspectable.oi = tblSerde.getObjectInspector();
return inspectable;
} else {
currRecReader.close();
currRecReader = null;
}
}
} catch (Exception e) {
throw new IOException(e);
}
}
/**
* Clear the context, if anything needs to be done.
*
**/
public void clearFetchContext() throws HiveException {
try {
if (currRecReader != null) {
currRecReader.close();
currRecReader = null;
}
if (operator != null) {
operator.close(false);
operator = null;
}
if (context != null) {
context.clear();
context = null;
}
this.currTbl = null;
this.currPath = null;
this.iterPath = null;
this.iterPartDesc = null;
} catch (Exception e) {
throw new HiveException("Failed with exception " + e.getMessage()
+ org.apache.hadoop.util.StringUtils.stringifyException(e));
}
}
/**
* used for bucket map join
*/
public void setupContext(List paths) {
this.iterPath = paths.iterator();
if (work.isNotPartitioned()) {
this.currTbl = work.getTblDesc();
} else {
this.iterPartDesc = work.getPartDescs(paths).iterator();
}
setupExecContext();
}
/**
* returns output ObjectInspector, never null
*/
public ObjectInspector getOutputObjectInspector() throws HiveException {
try {
if (work.isNotPartitioned()) {
return getRowInspectorFromTable(work.getTblDesc());
}
List listParts = work.getPartDesc();
// Chose the table descriptor if none of the partitions is present.
// For eg: consider the query:
// select /*+mapjoin(T1)*/ count(*) from T1 join T2 on T1.key=T2.key
// Both T1 and T2 and partitioned tables, but T1 does not have any partitions
// FetchOperator is invoked for T1, and listParts is empty. In that case,
// use T1's schema to get the ObjectInspector.
if (listParts == null || listParts.isEmpty()) {
return getRowInspectorFromPartitionedTable(work.getTblDesc());
}
// Choose any partition. It's OI needs to be converted to the table OI
// Whenever a new partition is being read, a new converter is being created
PartitionDesc partition = listParts.get(0);
Deserializer tblSerde = partition.getTableDesc().getDeserializerClass().newInstance();
tblSerde.initialize(job, partition.getTableDesc().getProperties());
partitionedTableOI = null;
ObjectInspector tableOI = tblSerde.getObjectInspector();
// Get the OI corresponding to all the partitions
for (PartitionDesc listPart : listParts) {
partition = listPart;
Deserializer partSerde = listPart.getDeserializerClass().newInstance();
partSerde.initialize(job, listPart.getProperties());
partitionedTableOI = ObjectInspectorConverters.getConvertedOI(
partSerde.getObjectInspector(), tableOI);
if (!partitionedTableOI.equals(tableOI)) {
break;
}
}
return getRowInspectorFromPartition(partition, partitionedTableOI);
} catch (Exception e) {
throw new HiveException("Failed with exception " + e.getMessage()
+ org.apache.hadoop.util.StringUtils.stringifyException(e));
} finally {
currPart = null;
}
}
/**
* Lists status for all files under a given path. Whether or not this is recursive depends on the
* setting of job configuration parameter mapred.input.dir.recursive.
*
* @param fs
* file system
*
* @param p
* path in file system
*
* @return list of file status entries
*/
private FileStatus[] listStatusUnderPath(FileSystem fs, Path p) throws IOException {
boolean recursive = HiveConf.getBoolVar(job, HiveConf.ConfVars.HADOOPMAPREDINPUTDIRRECURSIVE);
if (!recursive) {
return fs.listStatus(p);
}
List results = new ArrayList();
for (FileStatus stat : fs.listStatus(p)) {
FileUtils.listStatusRecursively(fs, stat, results);
}
return results.toArray(new FileStatus[results.size()]);
}
// for split sampling. shrinkedLength is checked against IOContext.getCurrentBlockStart,
// which is from RecordReader.getPos(). So some inputformats which does not support getPos()
// like HiveHBaseTableInputFormat cannot be used with this (todo)
private static class FetchInputFormatSplit extends HiveInputFormat.HiveInputSplit {
// shrinked size for this split. counter part of this in normal mode is
// InputSplitShim.shrinkedLength.
// what's different is that this is evaluated by unit of row using RecordReader.getPos()
// and that is evaluated by unit of split using InputSplt.getLength().
private long shrinkedLength = -1;
public FetchInputFormatSplit(InputSplit split, String name) {
super(split, name);
}
}
}
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