/**
* 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.io;
import java.io.DataInput;
import java.io.DataOutput;
import java.io.IOException;
import java.io.Serializable;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.Iterator;
import java.util.Map;
import java.util.Map.Entry;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.apache.hadoop.conf.Configurable;
import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.fs.Path;
import org.apache.hadoop.hive.io.HiveIOExceptionHandlerUtil;
import org.apache.hadoop.hive.ql.exec.Operator;
import org.apache.hadoop.hive.ql.exec.TableScanOperator;
import org.apache.hadoop.hive.ql.exec.Utilities;
import org.apache.hadoop.hive.ql.plan.ExprNodeDesc;
import org.apache.hadoop.hive.ql.plan.MapredWork;
import org.apache.hadoop.hive.ql.plan.PartitionDesc;
import org.apache.hadoop.hive.ql.plan.TableScanDesc;
import org.apache.hadoop.hive.serde2.ColumnProjectionUtils;
import org.apache.hadoop.hive.shims.ShimLoader;
import org.apache.hadoop.io.Writable;
import org.apache.hadoop.io.WritableComparable;
import org.apache.hadoop.mapred.FileInputFormat;
import org.apache.hadoop.mapred.FileSplit;
import org.apache.hadoop.mapred.InputFormat;
import org.apache.hadoop.mapred.InputSplit;
import org.apache.hadoop.mapred.JobConf;
import org.apache.hadoop.mapred.JobConfigurable;
import org.apache.hadoop.mapred.RecordReader;
import org.apache.hadoop.mapred.Reporter;
import org.apache.hadoop.util.ReflectionUtils;
/**
* HiveInputFormat is a parameterized InputFormat which looks at the path name
* and determine the correct InputFormat for that path name from
* mapredPlan.pathToPartitionInfo(). It can be used to read files with different
* input format in the same map-reduce job.
*/
public class HiveInputFormat<K extends WritableComparable, V extends Writable>
implements InputFormat<K, V>, JobConfigurable {
public static final Log LOG = LogFactory
.getLog("org.apache.hadoop.hive.ql.io.HiveInputFormat");
/**
* HiveInputSplit encapsulates an InputSplit with its corresponding
* inputFormatClass. The reason that it derives from FileSplit is to make sure
* "map.input.file" in MapTask.
*/
public static class HiveInputSplit extends FileSplit implements InputSplit,
Configurable {
InputSplit inputSplit;
String inputFormatClassName;
public HiveInputSplit() {
// This is the only public constructor of FileSplit
super((Path) null, 0, 0, (String[]) null);
}
public HiveInputSplit(InputSplit inputSplit, String inputFormatClassName) {
// This is the only public constructor of FileSplit
super((Path) null, 0, 0, (String[]) null);
this.inputSplit = inputSplit;
this.inputFormatClassName = inputFormatClassName;
}
public InputSplit getInputSplit() {
return inputSplit;
}
public String inputFormatClassName() {
return inputFormatClassName;
}
@Override
public Path getPath() {
if (inputSplit instanceof FileSplit) {
return ((FileSplit) inputSplit).getPath();
}
return new Path("");
}
/** The position of the first byte in the file to process. */
@Override
public long getStart() {
if (inputSplit instanceof FileSplit) {
return ((FileSplit) inputSplit).getStart();
}
return 0;
}
@Override
public String toString() {
return inputFormatClassName + ":" + inputSplit.toString();
}
@Override
public long getLength() {
long r = 0;
try {
r = inputSplit.getLength();
} catch (Exception e) {
throw new RuntimeException(e);
}
return r;
}
@Override
public String[] getLocations() throws IOException {
return inputSplit.getLocations();
}
@Override
public void readFields(DataInput in) throws IOException {
String inputSplitClassName = in.readUTF();
try {
inputSplit = (InputSplit) ReflectionUtils.newInstance(conf
.getClassByName(inputSplitClassName), conf);
} catch (Exception e) {
throw new IOException(
"Cannot create an instance of InputSplit class = "
+ inputSplitClassName + ":" + e.getMessage(), e);
}
inputSplit.readFields(in);
inputFormatClassName = in.readUTF();
}
@Override
public void write(DataOutput out) throws IOException {
out.writeUTF(inputSplit.getClass().getName());
inputSplit.write(out);
out.writeUTF(inputFormatClassName);
}
Configuration conf;
@Override
public Configuration getConf() {
return conf;
}
@Override
public void setConf(Configuration conf) {
this.conf = conf;
}
}
JobConf job;
public void configure(JobConf job) {
this.job = job;
}
/**
* A cache of InputFormat instances.
*/
protected static Map<Class, InputFormat<WritableComparable, Writable>> inputFormats;
public static InputFormat<WritableComparable, Writable> getInputFormatFromCache(
Class inputFormatClass, JobConf job) throws IOException {
if (inputFormats == null) {
inputFormats = new HashMap<Class, InputFormat<WritableComparable, Writable>>();
}
if (!inputFormats.containsKey(inputFormatClass)) {
try {
InputFormat<WritableComparable, Writable> newInstance = (InputFormat<WritableComparable, Writable>) ReflectionUtils
.newInstance(inputFormatClass, job);
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);
}
public RecordReader getRecordReader(InputSplit split, JobConf job,
Reporter reporter) throws IOException {
HiveInputSplit hsplit = (HiveInputSplit) split;
InputSplit inputSplit = hsplit.getInputSplit();
String inputFormatClassName = null;
Class inputFormatClass = null;
try {
inputFormatClassName = hsplit.inputFormatClassName();
inputFormatClass = job.getClassByName(inputFormatClassName);
} catch (Exception e) {
throw new IOException("cannot find class " + inputFormatClassName, e);
}
// clone a jobConf for setting needed columns for reading
JobConf cloneJobConf = new JobConf(job);
if (this.mrwork == null) {
init(job);
}
boolean nonNative = false;
PartitionDesc part = pathToPartitionInfo.get(hsplit.getPath().toString());
if ((part != null) && (part.getTableDesc() != null)) {
Utilities.copyTableJobPropertiesToConf(part.getTableDesc(), cloneJobConf);
nonNative = part.getTableDesc().isNonNative();
}
pushProjectionsAndFilters(cloneJobConf, inputFormatClass, hsplit.getPath()
.toString(), hsplit.getPath().toUri().getPath(), nonNative);
InputFormat inputFormat = getInputFormatFromCache(inputFormatClass,
cloneJobConf);
RecordReader innerReader = null;
try {
innerReader = inputFormat.getRecordReader(inputSplit,
cloneJobConf, reporter);
} catch (Exception e) {
innerReader = HiveIOExceptionHandlerUtil
.handleRecordReaderCreationException(e, cloneJobConf);
}
HiveRecordReader<K,V> rr = new HiveRecordReader(innerReader, job);
rr.initIOContext(hsplit, job, inputFormatClass, innerReader);
return rr;
}
protected Map<String, PartitionDesc> pathToPartitionInfo;
MapredWork mrwork = null;
protected void init(JobConf job) {
mrwork = Utilities.getMapRedWork(job);
pathToPartitionInfo = mrwork.getPathToPartitionInfo();
}
public InputSplit[] getSplits(JobConf job, int numSplits) throws IOException {
init(job);
Path[] dirs = FileInputFormat.getInputPaths(job);
if (dirs.length == 0) {
throw new IOException("No input paths specified in job");
}
JobConf newjob = new JobConf(job);
ArrayList<InputSplit> result = new ArrayList<InputSplit>();
// for each dir, get the InputFormat, and do getSplits.
for (Path dir : dirs) {
PartitionDesc part = getPartitionDescFromPath(pathToPartitionInfo, dir);
// create a new InputFormat instance if this is the first time to see this
// class
Class inputFormatClass = part.getInputFileFormatClass();
InputFormat inputFormat = getInputFormatFromCache(inputFormatClass, job);
Utilities.copyTableJobPropertiesToConf(part.getTableDesc(), newjob);
// Make filter pushdown information available to getSplits.
ArrayList<String> aliases =
mrwork.getPathToAliases().get(dir.toUri().toString());
if ((aliases != null) && (aliases.size() == 1)) {
Operator op = mrwork.getAliasToWork().get(aliases.get(0));
if ((op != null) && (op instanceof TableScanOperator)) {
TableScanOperator tableScan = (TableScanOperator) op;
pushFilters(newjob, tableScan);
}
}
FileInputFormat.setInputPaths(newjob, dir);
newjob.setInputFormat(inputFormat.getClass());
InputSplit[] iss = inputFormat.getSplits(newjob, numSplits / dirs.length);
for (InputSplit is : iss) {
result.add(new HiveInputSplit(is, inputFormatClass.getName()));
}
}
LOG.info("number of splits " + result.size());
return result.toArray(new HiveInputSplit[result.size()]);
}
public void validateInput(JobConf job) throws IOException {
init(job);
Path[] dirs = FileInputFormat.getInputPaths(job);
if (dirs.length == 0) {
throw new IOException("No input paths specified in job");
}
JobConf newjob = new JobConf(job);
// for each dir, get the InputFormat, and do validateInput.
for (Path dir : dirs) {
PartitionDesc part = getPartitionDescFromPath(pathToPartitionInfo, dir);
// create a new InputFormat instance if this is the first time to see this
// class
InputFormat inputFormat = getInputFormatFromCache(part
.getInputFileFormatClass(), job);
FileInputFormat.setInputPaths(newjob, dir);
newjob.setInputFormat(inputFormat.getClass());
ShimLoader.getHadoopShims().inputFormatValidateInput(inputFormat, newjob);
}
}
protected static PartitionDesc getPartitionDescFromPath(
Map<String, PartitionDesc> pathToPartitionInfo, Path dir)
throws IOException {
PartitionDesc partDesc = pathToPartitionInfo.get(dir.toString());
if (partDesc == null) {
partDesc = pathToPartitionInfo.get(dir.toUri().getPath());
}
if (partDesc == null) {
throw new IOException("cannot find dir = " + dir.toString()
+ " in partToPartitionInfo!");
}
return partDesc;
}
protected void pushFilters(JobConf jobConf, TableScanOperator tableScan) {
TableScanDesc scanDesc = tableScan.getConf();
if (scanDesc == null) {
return;
}
// construct column name list and types for reference by filter push down
Utilities.setColumnNameList(jobConf, tableScan);
Utilities.setColumnTypeList(jobConf, tableScan);
// push down filters
ExprNodeDesc filterExpr = scanDesc.getFilterExpr();
if (filterExpr == null) {
return;
}
String filterText = filterExpr.getExprString();
String filterExprSerialized = Utilities.serializeExpression(filterExpr);
if (LOG.isDebugEnabled()) {
LOG.debug("Filter text = " + filterText);
LOG.debug("Filter expression = " + filterExprSerialized);
}
jobConf.set(
TableScanDesc.FILTER_TEXT_CONF_STR,
filterText);
jobConf.set(
TableScanDesc.FILTER_EXPR_CONF_STR,
filterExprSerialized);
}
protected void pushProjectionsAndFilters(JobConf jobConf, Class inputFormatClass,
String splitPath, String splitPathWithNoSchema) {
pushProjectionsAndFilters(jobConf, inputFormatClass, splitPath,
splitPathWithNoSchema, false);
}
protected void pushProjectionsAndFilters(JobConf jobConf, Class inputFormatClass,
String splitPath, String splitPathWithNoSchema, boolean nonNative) {
if (this.mrwork == null) {
init(job);
}
if(this.mrwork.getPathToAliases() == null) {
return;
}
ArrayList<String> aliases = new ArrayList<String>();
Iterator<Entry<String, ArrayList<String>>> iterator = this.mrwork
.getPathToAliases().entrySet().iterator();
while (iterator.hasNext()) {
Entry<String, ArrayList<String>> entry = iterator.next();
String key = entry.getKey();
boolean match;
if (nonNative) {
// For non-native tables, we need to do an exact match to avoid
// HIVE-1903. (The table location contains no files, and the string
// representation of its path does not have a trailing slash.)
match =
splitPath.equals(key) || splitPathWithNoSchema.equals(key);
} else {
// But for native tables, we need to do a prefix match for
// subdirectories. (Unlike non-native tables, prefix mixups don't seem
// to be a potential problem here since we are always dealing with the
// path to something deeper than the table location.)
match =
splitPath.startsWith(key) || splitPathWithNoSchema.startsWith(key);
}
if (match) {
ArrayList<String> list = entry.getValue();
for (String val : list) {
aliases.add(val);
}
}
}
for (String alias : aliases) {
Operator<? extends Serializable> op = this.mrwork.getAliasToWork().get(
alias);
if (op != null && op instanceof TableScanOperator) {
TableScanOperator tableScan = (TableScanOperator) op;
// push down projections
ArrayList<Integer> list = tableScan.getNeededColumnIDs();
if (list != null) {
ColumnProjectionUtils.appendReadColumnIDs(jobConf, list);
} else {
ColumnProjectionUtils.setFullyReadColumns(jobConf);
}
pushFilters(jobConf, tableScan);
}
}
}
}