/**
* 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
*3
* 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.mahout.text;
import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.fs.FileSystem;
import org.apache.hadoop.fs.Path;
import org.apache.hadoop.io.Writable;
import org.apache.hadoop.mapreduce.InputSplit;
import org.apache.lucene.index.SegmentCommitInfo;
import org.apache.lucene.index.SegmentInfo;
import org.apache.lucene.index.SegmentInfos;
import java.io.DataInput;
import java.io.DataOutput;
import java.io.IOException;
/**
* {@link InputSplit} implementation that represents a Lucene segment.
*/
public class LuceneSegmentInputSplit extends InputSplit implements Writable {
private Path indexPath;
private String segmentInfoName;
private long length;
public LuceneSegmentInputSplit() {
// For deserialization
}
public LuceneSegmentInputSplit(Path indexPath, String segmentInfoName, long length) {
this.indexPath = indexPath;
this.segmentInfoName = segmentInfoName;
this.length = length;
}
@Override
public long getLength() throws IOException, InterruptedException {
return length;
}
@Override
public String[] getLocations() throws IOException, InterruptedException {
return new String[]{};
}
public String getSegmentInfoName() {
return segmentInfoName;
}
public Path getIndexPath() {
return indexPath;
}
@Override
public void write(DataOutput out) throws IOException {
out.writeUTF(indexPath.toString());
out.writeUTF(segmentInfoName);
out.writeLong(length);
}
@Override
public void readFields(DataInput in) throws IOException {
this.indexPath = new Path(in.readUTF());
this.segmentInfoName = in.readUTF();
this.length = in.readLong();
}
/**
* Get the {@link SegmentInfo} of this {@link InputSplit} via the given {@link Configuration}
*
* @param configuration the configuration used to locate the index
* @return the segment info or throws exception if not found
* @throws IOException if an error occurs when accessing the directory
*/
public SegmentCommitInfo getSegment(Configuration configuration) throws IOException {
ReadOnlyFileSystemDirectory directory = new ReadOnlyFileSystemDirectory(FileSystem.get(configuration), indexPath,
false, configuration);
SegmentInfos segmentInfos = new SegmentInfos();
segmentInfos.read(directory);
for (SegmentCommitInfo segmentInfo : segmentInfos) {
if (segmentInfo.info.name.equals(segmentInfoName)) {
return segmentInfo;
}
}
throw new IllegalArgumentException("No such segment: '" + segmentInfoName
+ "' in directory " + directory.toString());
}
}