// Copyright (c) 2013, Facebook, Inc. All rights reserved.
/**
* 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 com.facebook.hive.orc;
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.conf.Configuration;
import org.apache.hadoop.fs.FSDataInputStream;
import org.apache.hadoop.fs.FileStatus;
import org.apache.hadoop.fs.FileSystem;
import org.apache.hadoop.fs.Path;
import org.apache.hadoop.hive.conf.HiveConf;
import org.apache.hadoop.hive.ql.io.InputFormatChecker;
import org.apache.hadoop.hive.serde2.ColumnProjectionUtils;
import org.apache.hadoop.hive.serde2.ReaderWriterProfiler;
import org.apache.hadoop.hive.serde2.objectinspector.ObjectInspector;
import org.apache.hadoop.io.IOUtils;
import org.apache.hadoop.io.NullWritable;
import org.apache.hadoop.mapred.FileInputFormat;
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 com.facebook.hive.orc.lazy.OrcLazyRow;
/**
* A MapReduce/Hive input format for ORC files.
*/
public class OrcInputFormat extends FileInputFormat<NullWritable, OrcLazyRow>
implements InputFormatChecker {
private static final Log LOG = LogFactory.getLog(OrcInputFormat.class);
public static class OrcRecordReader
implements RecordReader<NullWritable, OrcLazyRow> {
private final com.facebook.hive.orc.RecordReader reader;
private final long offset;
private final long length;
private float progress = 0.0f;
private ObjectInspector objectInspector = null;
OrcRecordReader(Reader file, Configuration conf,
long offset, long length) throws IOException {
this.reader = file.rows(offset, length,
findIncludedColumns(file.getTypes(), conf));
this.offset = offset;
this.length = length;
this.objectInspector = file.getObjectInspector();
}
@Override
public boolean next(NullWritable key, OrcLazyRow value) throws IOException {
if (reader.hasNext()) {
reader.next(value);
progress = reader.getProgress();
return true;
} else {
return false;
}
}
@Override
public NullWritable createKey() {
return NullWritable.get();
}
@Override
public OrcLazyRow createValue() {
return reader.getReader();
}
@Override
public long getPos() throws IOException {
return offset + (long) (progress * length);
}
@Override
public void close() throws IOException {
reader.close();
}
@Override
public float getProgress() throws IOException {
return progress;
}
public ObjectInspector getObjectInspector() throws IOException {
return objectInspector;
}
}
public OrcInputFormat() {
// just set a really small lower bound
setMinSplitSize(16 * 1024);
}
/**
* Recurse down into a type subtree turning on all of the sub-columns.
* @param types the types of the file
* @param result the global view of columns that should be included
* @param typeId the root of tree to enable
*/
private static void includeColumnRecursive(List<OrcProto.Type> types,
boolean[] result,
int typeId) {
result[typeId] = true;
OrcProto.Type type = types.get(typeId);
int children = type.getSubtypesCount();
for(int i=0; i < children; ++i) {
includeColumnRecursive(types, result, type.getSubtypes(i));
}
}
/**
* Take the configuration and figure out which columns we need to include.
* @param types the types of the file
* @param conf the configuration
* @return true for each column that should be included
*/
private static boolean[] findIncludedColumns(List<OrcProto.Type> types,
Configuration conf) {
String includedStr =
conf.get(ColumnProjectionUtils.READ_COLUMN_IDS_CONF_STR);
if (includedStr == null || includedStr.trim().length() == 0) {
return null;
} else {
int numColumns = types.size();
boolean[] result = new boolean[numColumns];
result[0] = true;
OrcProto.Type root = types.get(0);
List<Integer> included = ColumnProjectionUtils.getReadColumnIDs(conf);
for(int i=0; i < root.getSubtypesCount(); ++i) {
if (included.contains(i)) {
includeColumnRecursive(types, result, root.getSubtypes(i));
}
}
// if we are filtering at least one column, return the boolean array
for(boolean include: result) {
if (!include) {
return result;
}
}
return null;
}
}
@Override
public RecordReader<NullWritable, OrcLazyRow>
getRecordReader(InputSplit inputSplit, JobConf conf,
Reporter reporter) throws IOException {
ReaderWriterProfiler.setProfilerOptions(conf);
FileSplit fileSplit = (FileSplit) inputSplit;
Path path = fileSplit.getPath();
FileSystem fs = path.getFileSystem(conf);
reporter.setStatus(fileSplit.toString());
try {
return new OrcRecordReader(
OrcFile.createReader(fs, path, conf),
conf,
fileSplit.getStart(),
fileSplit.getLength());
} catch (IndexOutOfBoundsException e) {
/**
* When a non ORC file is read by ORC reader, we get IndexOutOfBoundsException exception while
* creating a reader. Caught that exception and checked the file header to see if the input
* file was ORC or not. If its not ORC, throw a NotAnORCFileException with the file
* attempted to be reading (thus helping to figure out which table-partition was being read).
*/
checkIfORC(fs, path);
throw new IOException("Failed to create record reader for file " + path , e);
} catch (IOException e) {
throw new IOException("Failed to create record reader for file " + path , e);
}
}
/**
* Reads the file header (first 40 bytes) and checks if the first three characters are 'ORC'.
*/
private static void checkIfORC(FileSystem fs, Path path) throws IOException {
// hardcoded to 40 because "SEQ-org.apache.hadoop.hive.ql.io.RCFile", the header, is of 40 chars
final int buffLen = 40;
final byte header[] = new byte[buffLen];
final FSDataInputStream file = fs.open(path);
final long fileLength = fs.getFileStatus(path).getLen();
int sizeToBeRead = buffLen;
if (buffLen > fileLength) {
sizeToBeRead = (int)fileLength;
}
IOUtils.readFully(file, header, 0, sizeToBeRead);
file.close();
final String headerString = new String(header);
if (headerString.startsWith("ORC")) {
LOG.error("Error while parsing the footer of the file : " + path);
} else {
throw new NotAnORCFileException("Input file = " + path + " , header = " + headerString);
}
}
@Override
public boolean validateInput(FileSystem fs, HiveConf conf,
ArrayList<FileStatus> files
) throws IOException {
if (files.size() <= 0) {
return false;
}
for (FileStatus file : files) {
try {
OrcFile.createReader(fs, file.getPath(), conf);
} catch (IOException e) {
return false;
}
}
return true;
}
}