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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.hive.hcatalog.mapreduce;
import java.io.IOException;
import java.util.ArrayList;
import java.util.LinkedList;
import java.util.Map;
import java.util.HashMap;
import java.util.List;
import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.fs.FileSystem;
import org.apache.hadoop.fs.Path;
import org.apache.hadoop.hive.ql.metadata.HiveStorageHandler;
import org.apache.hadoop.io.WritableComparable;
import org.apache.hadoop.io.Writable;
import org.apache.hadoop.mapred.JobConf;
import org.apache.hadoop.mapreduce.InputFormat;
import org.apache.hadoop.mapreduce.InputSplit;
import org.apache.hadoop.mapreduce.Job;
import org.apache.hadoop.mapreduce.JobContext;
import org.apache.hadoop.mapreduce.RecordReader;
import org.apache.hadoop.mapreduce.TaskAttemptContext;
import org.apache.hadoop.util.ReflectionUtils;
import org.apache.hadoop.util.StringUtils;
import org.apache.hive.hcatalog.common.HCatConstants;
import org.apache.hive.hcatalog.common.HCatUtil;
import org.apache.hive.hcatalog.data.HCatRecord;
import org.apache.hive.hcatalog.data.schema.HCatFieldSchema;
import org.apache.hive.hcatalog.data.schema.HCatSchema;
public abstract class HCatBaseInputFormat
extends InputFormat<WritableComparable, HCatRecord> {
/**
* get the schema for the HCatRecord data returned by HCatInputFormat.
*
* @param context the jobContext
* @throws IllegalArgumentException
*/
private Class<? extends InputFormat> inputFileFormatClass;
// TODO needs to go in InitializeInput? as part of InputJobInfo
private static HCatSchema getOutputSchema(Configuration conf)
throws IOException {
String os = conf.get(HCatConstants.HCAT_KEY_OUTPUT_SCHEMA);
if (os == null) {
return getTableSchema(conf);
} else {
return (HCatSchema) HCatUtil.deserialize(os);
}
}
/**
* Set the schema for the HCatRecord data returned by HCatInputFormat.
* @param job the job object
* @param hcatSchema the schema to use as the consolidated schema
*/
public static void setOutputSchema(Job job, HCatSchema hcatSchema)
throws IOException {
job.getConfiguration().set(HCatConstants.HCAT_KEY_OUTPUT_SCHEMA,
HCatUtil.serialize(hcatSchema));
}
protected static org.apache.hadoop.mapred.InputFormat<WritableComparable, Writable>
getMapRedInputFormat(JobConf job, Class inputFormatClass) throws IOException {
return (
org.apache.hadoop.mapred.InputFormat<WritableComparable, Writable>)
ReflectionUtils.newInstance(inputFormatClass, job);
}
/**
* Logically split the set of input files for the job. Returns the
* underlying InputFormat's splits
* @param jobContext the job context object
* @return the splits, an HCatInputSplit wrapper over the storage
* handler InputSplits
* @throws IOException or InterruptedException
*/
@Override
public List<InputSplit> getSplits(JobContext jobContext)
throws IOException, InterruptedException {
Configuration conf = jobContext.getConfiguration();
//Get the job info from the configuration,
//throws exception if not initialized
InputJobInfo inputJobInfo;
try {
inputJobInfo = getJobInfo(conf);
} catch (Exception e) {
throw new IOException(e);
}
List<InputSplit> splits = new ArrayList<InputSplit>();
List<PartInfo> partitionInfoList = inputJobInfo.getPartitions();
if (partitionInfoList == null) {
//No partitions match the specified partition filter
return splits;
}
HiveStorageHandler storageHandler;
JobConf jobConf;
//For each matching partition, call getSplits on the underlying InputFormat
for (PartInfo partitionInfo : partitionInfoList) {
jobConf = HCatUtil.getJobConfFromContext(jobContext);
setInputPath(jobConf, partitionInfo.getLocation());
Map<String, String> jobProperties = partitionInfo.getJobProperties();
HCatSchema allCols = new HCatSchema(new LinkedList<HCatFieldSchema>());
for (HCatFieldSchema field :
inputJobInfo.getTableInfo().getDataColumns().getFields())
allCols.append(field);
for (HCatFieldSchema field :
inputJobInfo.getTableInfo().getPartitionColumns().getFields())
allCols.append(field);
HCatUtil.copyJobPropertiesToJobConf(jobProperties, jobConf);
storageHandler = HCatUtil.getStorageHandler(
jobConf, partitionInfo);
//Get the input format
Class inputFormatClass = storageHandler.getInputFormatClass();
org.apache.hadoop.mapred.InputFormat inputFormat =
getMapRedInputFormat(jobConf, inputFormatClass);
//Call getSplit on the InputFormat, create an HCatSplit for each
//underlying split. When the desired number of input splits is missing,
//use a default number (denoted by zero).
//TODO(malewicz): Currently each partition is split independently into
//a desired number. However, we want the union of all partitions to be
//split into a desired number while maintaining balanced sizes of input
//splits.
int desiredNumSplits =
conf.getInt(HCatConstants.HCAT_DESIRED_PARTITION_NUM_SPLITS, 0);
org.apache.hadoop.mapred.InputSplit[] baseSplits =
inputFormat.getSplits(jobConf, desiredNumSplits);
for (org.apache.hadoop.mapred.InputSplit split : baseSplits) {
splits.add(new HCatSplit(
partitionInfo,
split, allCols));
}
}
return splits;
}
/**
* Create the RecordReader for the given InputSplit. Returns the underlying
* RecordReader if the required operations are supported and schema matches
* with HCatTable schema. Returns an HCatRecordReader if operations need to
* be implemented in HCat.
* @param split the split
* @param taskContext the task attempt context
* @return the record reader instance, either an HCatRecordReader(later) or
* the underlying storage handler's RecordReader
* @throws IOException or InterruptedException
*/
@Override
public RecordReader<WritableComparable, HCatRecord>
createRecordReader(InputSplit split,
TaskAttemptContext taskContext) throws IOException, InterruptedException {
HCatSplit hcatSplit = InternalUtil.castToHCatSplit(split);
PartInfo partitionInfo = hcatSplit.getPartitionInfo();
JobContext jobContext = taskContext;
Configuration conf = jobContext.getConfiguration();
HiveStorageHandler storageHandler = HCatUtil.getStorageHandler(
conf, partitionInfo);
JobConf jobConf = HCatUtil.getJobConfFromContext(jobContext);
Map<String, String> jobProperties = partitionInfo.getJobProperties();
HCatUtil.copyJobPropertiesToJobConf(jobProperties, jobConf);
Map<String, String> valuesNotInDataCols = getColValsNotInDataColumns(
getOutputSchema(conf), partitionInfo
);
return new HCatRecordReader(storageHandler, valuesNotInDataCols);
}
/**
* gets values for fields requested by output schema which will not be in the data
*/
private static Map<String, String> getColValsNotInDataColumns(HCatSchema outputSchema,
PartInfo partInfo) {
HCatSchema dataSchema = partInfo.getPartitionSchema();
Map<String, String> vals = new HashMap<String, String>();
for (String fieldName : outputSchema.getFieldNames()) {
if (dataSchema.getPosition(fieldName) == null) {
// this entry of output is not present in the output schema
// so, we first check the table schema to see if it is a part col
if (partInfo.getPartitionValues().containsKey(fieldName)) {
vals.put(fieldName, partInfo.getPartitionValues().get(fieldName));
} else {
vals.put(fieldName, null);
}
}
}
return vals;
}
/**
* @see org.apache.hive.hcatalog.mapreduce.HCatBaseInputFormat#getTableSchema(org.apache.hadoop.conf.Configuration)
* @deprecated Use {@link #getTableSchema(org.apache.hadoop.conf.Configuration)}
*/
public static HCatSchema getTableSchema(JobContext context)
throws IOException {
return getTableSchema(context.getConfiguration());
}
/**
* Gets the HCatTable schema for the table specified in the HCatInputFormat.setInput call
* on the specified job context. This information is available only after HCatInputFormat.setInput
* has been called for a JobContext.
* @param conf the Configuration object
* @return the table schema
* @throws IOException if HCatInputFormat.setInput has not been called
* for the current context
*/
public static HCatSchema getTableSchema(Configuration conf)
throws IOException {
InputJobInfo inputJobInfo = getJobInfo(conf);
HCatSchema allCols = new HCatSchema(new LinkedList<HCatFieldSchema>());
for (HCatFieldSchema field :
inputJobInfo.getTableInfo().getDataColumns().getFields())
allCols.append(field);
for (HCatFieldSchema field :
inputJobInfo.getTableInfo().getPartitionColumns().getFields())
allCols.append(field);
return allCols;
}
/**
* Gets the InputJobInfo object by reading the Configuration and deserializing
* the string. If InputJobInfo is not present in the configuration, throws an
* exception since that means HCatInputFormat.setInput has not been called.
* @param conf the Configuration object
* @return the InputJobInfo object
* @throws IOException the exception
*/
private static InputJobInfo getJobInfo(Configuration conf)
throws IOException {
String jobString = conf.get(
HCatConstants.HCAT_KEY_JOB_INFO);
if (jobString == null) {
throw new IOException("job information not found in JobContext."
+ " HCatInputFormat.setInput() not called?");
}
return (InputJobInfo) HCatUtil.deserialize(jobString);
}
private void setInputPath(JobConf jobConf, String location)
throws IOException {
// ideally we should just call FileInputFormat.setInputPaths() here - but
// that won't work since FileInputFormat.setInputPaths() needs
// a Job object instead of a JobContext which we are handed here
int length = location.length();
int curlyOpen = 0;
int pathStart = 0;
boolean globPattern = false;
List<String> pathStrings = new ArrayList<String>();
for (int i = 0; i < length; i++) {
char ch = location.charAt(i);
switch (ch) {
case '{': {
curlyOpen++;
if (!globPattern) {
globPattern = true;
}
break;
}
case '}': {
curlyOpen--;
if (curlyOpen == 0 && globPattern) {
globPattern = false;
}
break;
}
case ',': {
if (!globPattern) {
pathStrings.add(location.substring(pathStart, i));
pathStart = i + 1;
}
break;
}
}
}
pathStrings.add(location.substring(pathStart, length));
Path[] paths = StringUtils.stringToPath(pathStrings.toArray(new String[0]));
String separator = "";
StringBuilder str = new StringBuilder();
for (Path path : paths) {
FileSystem fs = path.getFileSystem(jobConf);
final String qualifiedPath = fs.makeQualified(path).toString();
str.append(separator)
.append(StringUtils.escapeString(qualifiedPath));
separator = StringUtils.COMMA_STR;
}
jobConf.set("mapred.input.dir", str.toString());
}
}