/**
* 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.nutch.indexer;
import java.io.*;
import java.util.*;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.apache.hadoop.fs.*;
import org.apache.hadoop.mapred.FileAlreadyExistsException;
import org.apache.hadoop.util.*;
import org.apache.hadoop.conf.*;
import org.apache.nutch.util.HadoopFSUtil;
import org.apache.nutch.util.LogUtil;
import org.apache.nutch.util.NutchConfiguration;
import org.apache.lucene.store.Directory;
import org.apache.lucene.store.FSDirectory;
import org.apache.lucene.index.IndexWriter;
import org.apache.lucene.index.LogMergePolicy;
import org.apache.lucene.index.IndexWriter.MaxFieldLength;
/*************************************************************************
* IndexMerger creates an index for the output corresponding to a
* single fetcher run.
*
* @author Doug Cutting
* @author Mike Cafarella
*************************************************************************/
public class IndexMerger extends Configured implements Tool {
public static final Log LOG = LogFactory.getLog(IndexMerger.class);
public static final String DONE_NAME = "merge.done";
public IndexMerger() {
}
public IndexMerger(Configuration conf) {
setConf(conf);
}
/**
* Merge all input indexes to the single output index
*/
public void merge(Path[] indexes, Path outputIndex, Path localWorkingDir) throws IOException {
LOG.info("merging indexes to: " + outputIndex);
FileSystem localFs = FileSystem.getLocal(getConf());
if (localFs.exists(localWorkingDir)) {
localFs.delete(localWorkingDir, true);
}
localFs.mkdirs(localWorkingDir);
// Get local output target
//
FileSystem fs = FileSystem.get(getConf());
if (fs.exists(outputIndex)) {
throw new FileAlreadyExistsException("Output directory " + outputIndex + " already exists!");
}
Path tmpLocalOutput = new Path(localWorkingDir, "merge-output");
Path localOutput = fs.startLocalOutput(outputIndex, tmpLocalOutput);
Directory[] dirs = new Directory[indexes.length];
for (int i = 0; i < indexes.length; i++) {
if (LOG.isInfoEnabled()) { LOG.info("Adding " + indexes[i]); }
dirs[i] = new FsDirectory(fs, indexes[i], false, getConf());
}
//
// Merge indices
//
IndexWriter writer = new IndexWriter(
FSDirectory.open(new File(localOutput.toString())), null, true,
MaxFieldLength.UNLIMITED);
writer.setMergeFactor(getConf().getInt("indexer.mergeFactor", LogMergePolicy.DEFAULT_MERGE_FACTOR));
writer.setMaxBufferedDocs(getConf().getInt("indexer.minMergeDocs", IndexWriter.DEFAULT_MAX_BUFFERED_DOCS));
writer.setMaxMergeDocs(getConf().getInt("indexer.maxMergeDocs", LogMergePolicy.DEFAULT_MAX_MERGE_DOCS));
writer.setTermIndexInterval(getConf().getInt("indexer.termIndexInterval", IndexWriter.DEFAULT_TERM_INDEX_INTERVAL));
writer.setInfoStream(LogUtil.getDebugStream(LOG));
writer.setUseCompoundFile(false);
writer.setSimilarity(new NutchSimilarity());
writer.addIndexesNoOptimize(dirs);
writer.optimize();
writer.close();
//
// Put target back
//
fs.completeLocalOutput(outputIndex, tmpLocalOutput);
LOG.info("done merging");
}
/**
* Create an index for the input files in the named directory.
*/
public static void main(String[] args) throws Exception {
int res = ToolRunner.run(NutchConfiguration.create(), new IndexMerger(), args);
System.exit(res);
}
public int run(String[] args) throws Exception {
String usage = "IndexMerger [-workingdir <workingdir>] outputIndex indexesDir...";
if (args.length < 2) {
System.err.println("Usage: " + usage);
return -1;
}
//
// Parse args, read all index directories to be processed
//
FileSystem fs = FileSystem.get(getConf());
List<Path> indexDirs = new ArrayList<Path>();
Path workDir = new Path("indexmerger-" + System.currentTimeMillis());
int i = 0;
if ("-workingdir".equals(args[i])) {
i++;
workDir = new Path(args[i++], "indexmerger-" + System.currentTimeMillis());
}
Path outputIndex = new Path(args[i++]);
for (; i < args.length; i++) {
FileStatus[] fstats = fs.listStatus(new Path(args[i]), HadoopFSUtil.getPassDirectoriesFilter(fs));
indexDirs.addAll(Arrays.asList(HadoopFSUtil.getPaths(fstats)));
}
//
// Merge the indices
//
Path[] indexFiles = (Path[])indexDirs.toArray(new Path[indexDirs.size()]);
try {
merge(indexFiles, outputIndex, workDir);
return 0;
} catch (Exception e) {
LOG.fatal("IndexMerger: " + StringUtils.stringifyException(e));
return -1;
} finally {
FileSystem.getLocal(getConf()).delete(workDir, true);
}
}
}