/*
* 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.flink.api.java.hadoop.mapred;
import org.apache.flink.annotation.Internal;
import org.apache.flink.api.common.io.FileInputFormat.FileBaseStatistics;
import org.apache.flink.api.common.io.LocatableInputSplitAssigner;
import org.apache.flink.api.common.io.statistics.BaseStatistics;
import org.apache.flink.api.java.hadoop.common.HadoopInputFormatCommonBase;
import org.apache.flink.api.java.hadoop.mapred.utils.HadoopUtils;
import org.apache.flink.api.java.hadoop.mapred.wrapper.HadoopDummyReporter;
import org.apache.flink.api.java.hadoop.mapred.wrapper.HadoopInputSplit;
import org.apache.flink.configuration.Configuration;
import org.apache.flink.core.fs.FileStatus;
import org.apache.flink.core.fs.FileSystem;
import org.apache.flink.core.fs.Path;
import org.apache.flink.core.io.InputSplitAssigner;
import org.apache.hadoop.conf.Configurable;
import org.apache.hadoop.mapred.FileInputFormat;
import org.apache.hadoop.mapred.JobConf;
import org.apache.hadoop.mapred.JobConfigurable;
import org.apache.hadoop.mapred.RecordReader;
import org.apache.hadoop.security.Credentials;
import org.apache.hadoop.security.UserGroupInformation;
import org.apache.hadoop.util.ReflectionUtils;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import java.io.IOException;
import java.io.ObjectInputStream;
import java.io.ObjectOutputStream;
import java.util.ArrayList;
/**
* Common base for Java and Scala API for using Hadoop input formats with Flink.
*
* @param <K> Type of key
* @param <V> Type of value
* @param <T> The type iself
*/
@Internal
public abstract class HadoopInputFormatBase<K, V, T> extends HadoopInputFormatCommonBase<T, HadoopInputSplit> {
private static final long serialVersionUID = 1L;
private static final Logger LOG = LoggerFactory.getLogger(HadoopInputFormatBase.class);
// Mutexes to avoid concurrent operations on Hadoop InputFormats.
// Hadoop parallelizes tasks across JVMs which is why they might rely on this JVM isolation.
// In contrast, Flink parallelizes using Threads, so multiple Hadoop InputFormat instances
// might be used in the same JVM.
private static final Object OPEN_MUTEX = new Object();
private static final Object CONFIGURE_MUTEX = new Object();
private static final Object CLOSE_MUTEX = new Object();
private org.apache.hadoop.mapred.InputFormat<K, V> mapredInputFormat;
protected Class<K> keyClass;
protected Class<V> valueClass;
private JobConf jobConf;
protected transient K key;
protected transient V value;
private transient RecordReader<K, V> recordReader;
protected transient boolean fetched = false;
protected transient boolean hasNext;
public HadoopInputFormatBase(org.apache.hadoop.mapred.InputFormat<K, V> mapredInputFormat, Class<K> key, Class<V> value, JobConf job) {
super(job.getCredentials());
this.mapredInputFormat = mapredInputFormat;
this.keyClass = key;
this.valueClass = value;
HadoopUtils.mergeHadoopConf(job);
this.jobConf = job;
ReflectionUtils.setConf(mapredInputFormat, jobConf);
}
public JobConf getJobConf() {
return jobConf;
}
// --------------------------------------------------------------------------------------------
// InputFormat
// --------------------------------------------------------------------------------------------
@Override
public void configure(Configuration parameters) {
// enforce sequential configuration() calls
synchronized (CONFIGURE_MUTEX) {
// configure MR InputFormat if necessary
if (this.mapredInputFormat instanceof Configurable) {
((Configurable) this.mapredInputFormat).setConf(this.jobConf);
} else if (this.mapredInputFormat instanceof JobConfigurable) {
((JobConfigurable) this.mapredInputFormat).configure(this.jobConf);
}
}
}
@Override
public BaseStatistics getStatistics(BaseStatistics cachedStats) throws IOException {
// only gather base statistics for FileInputFormats
if(!(mapredInputFormat instanceof FileInputFormat)) {
return null;
}
final FileBaseStatistics cachedFileStats = (cachedStats != null && cachedStats instanceof FileBaseStatistics) ?
(FileBaseStatistics) cachedStats : null;
try {
final org.apache.hadoop.fs.Path[] paths = FileInputFormat.getInputPaths(this.jobConf);
return getFileStats(cachedFileStats, paths, new ArrayList<FileStatus>(1));
} catch (IOException ioex) {
if (LOG.isWarnEnabled()) {
LOG.warn("Could not determine statistics due to an io error: "
+ ioex.getMessage());
}
} catch (Throwable t) {
if (LOG.isErrorEnabled()) {
LOG.error("Unexpected problem while getting the file statistics: "
+ t.getMessage(), t);
}
}
// no statistics available
return null;
}
@Override
public HadoopInputSplit[] createInputSplits(int minNumSplits)
throws IOException {
org.apache.hadoop.mapred.InputSplit[] splitArray = mapredInputFormat.getSplits(jobConf, minNumSplits);
HadoopInputSplit[] hiSplit = new HadoopInputSplit[splitArray.length];
for (int i=0; i<splitArray.length; i++) {
hiSplit[i] = new HadoopInputSplit(i, splitArray[i], jobConf);
}
return hiSplit;
}
@Override
public InputSplitAssigner getInputSplitAssigner(HadoopInputSplit[] inputSplits) {
return new LocatableInputSplitAssigner(inputSplits);
}
@Override
public void open(HadoopInputSplit split) throws IOException {
// enforce sequential open() calls
synchronized (OPEN_MUTEX) {
this.recordReader = this.mapredInputFormat.getRecordReader(split.getHadoopInputSplit(), jobConf, new HadoopDummyReporter());
if (this.recordReader instanceof Configurable) {
((Configurable) this.recordReader).setConf(jobConf);
}
key = this.recordReader.createKey();
value = this.recordReader.createValue();
this.fetched = false;
}
}
@Override
public boolean reachedEnd() throws IOException {
if (!fetched) {
fetchNext();
}
return !hasNext;
}
protected void fetchNext() throws IOException {
hasNext = this.recordReader.next(key, value);
fetched = true;
}
@Override
public void close() throws IOException {
if (this.recordReader != null) {
// enforce sequential close() calls
synchronized (CLOSE_MUTEX) {
this.recordReader.close();
}
}
}
// --------------------------------------------------------------------------------------------
// Helper methods
// --------------------------------------------------------------------------------------------
private FileBaseStatistics getFileStats(FileBaseStatistics cachedStats, org.apache.hadoop.fs.Path[] hadoopFilePaths,
ArrayList<FileStatus> files) throws IOException {
long latestModTime = 0L;
// get the file info and check whether the cached statistics are still valid.
for(org.apache.hadoop.fs.Path hadoopPath : hadoopFilePaths) {
final Path filePath = new Path(hadoopPath.toUri());
final FileSystem fs = FileSystem.get(filePath.toUri());
final FileStatus file = fs.getFileStatus(filePath);
latestModTime = Math.max(latestModTime, file.getModificationTime());
// enumerate all files and check their modification time stamp.
if (file.isDir()) {
FileStatus[] fss = fs.listStatus(filePath);
files.ensureCapacity(files.size() + fss.length);
for (FileStatus s : fss) {
if (!s.isDir()) {
files.add(s);
latestModTime = Math.max(s.getModificationTime(), latestModTime);
}
}
} else {
files.add(file);
}
}
// check whether the cached statistics are still valid, if we have any
if (cachedStats != null && latestModTime <= cachedStats.getLastModificationTime()) {
return cachedStats;
}
// calculate the whole length
long len = 0;
for (FileStatus s : files) {
len += s.getLen();
}
// sanity check
if (len <= 0) {
len = BaseStatistics.SIZE_UNKNOWN;
}
return new FileBaseStatistics(latestModTime, len, BaseStatistics.AVG_RECORD_BYTES_UNKNOWN);
}
// --------------------------------------------------------------------------------------------
// Custom serialization methods
// --------------------------------------------------------------------------------------------
private void writeObject(ObjectOutputStream out) throws IOException {
super.write(out);
out.writeUTF(mapredInputFormat.getClass().getName());
out.writeUTF(keyClass.getName());
out.writeUTF(valueClass.getName());
jobConf.write(out);
}
@SuppressWarnings("unchecked")
private void readObject(ObjectInputStream in) throws IOException, ClassNotFoundException {
super.read(in);
String hadoopInputFormatClassName = in.readUTF();
String keyClassName = in.readUTF();
String valueClassName = in.readUTF();
if(jobConf == null) {
jobConf = new JobConf();
}
jobConf.readFields(in);
try {
this.mapredInputFormat = (org.apache.hadoop.mapred.InputFormat<K,V>) Class.forName(hadoopInputFormatClassName, true, Thread.currentThread().getContextClassLoader()).newInstance();
} catch (Exception e) {
throw new RuntimeException("Unable to instantiate the hadoop input format", e);
}
try {
this.keyClass = (Class<K>) Class.forName(keyClassName, true, Thread.currentThread().getContextClassLoader());
} catch (Exception e) {
throw new RuntimeException("Unable to find key class.", e);
}
try {
this.valueClass = (Class<V>) Class.forName(valueClassName, true, Thread.currentThread().getContextClassLoader());
} catch (Exception e) {
throw new RuntimeException("Unable to find value class.", e);
}
ReflectionUtils.setConf(mapredInputFormat, jobConf);
jobConf.getCredentials().addAll(this.credentials);
Credentials currentUserCreds = getCredentialsFromUGI(UserGroupInformation.getCurrentUser());
if(currentUserCreds != null) {
jobConf.getCredentials().addAll(currentUserCreds);
}
}
}