package proj.zoie.impl.indexing.internal;
/**
* 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.
*/
import it.unimi.dsi.fastutil.longs.LongSet;
import java.io.IOException;
import java.nio.channels.ReadableByteChannel;
import org.apache.log4j.Logger;
import org.apache.lucene.analysis.Analyzer;
import org.apache.lucene.index.IndexReader;
import org.apache.lucene.index.IndexWriter;
import org.apache.lucene.index.SerialMergeScheduler;
import org.apache.lucene.index.IndexWriter.MaxFieldLength;
import org.apache.lucene.search.Similarity;
import org.apache.lucene.store.Directory;
import proj.zoie.api.DirectoryManager;
import proj.zoie.api.ZoieHealth;
import proj.zoie.api.ZoieIndexReader;
import proj.zoie.api.ZoieVersion;
import proj.zoie.api.impl.ZoieMergePolicy;
import proj.zoie.api.impl.ZoieMergePolicy.MergePolicyParams;
import proj.zoie.api.impl.util.IndexUtil;
import proj.zoie.api.indexing.IndexReaderDecorator;
public class DiskSearchIndex<R extends IndexReader, V extends ZoieVersion> extends BaseSearchIndex<R,V>{
private final DirectoryManager<V> _dirMgr;
private final IndexReaderDispenser<R,V> _dispenser;
final MergePolicyParams _mergePolicyParams;
private ZoieIndexDeletionPolicy _deletionPolicy;
public static final Logger log = Logger.getLogger(DiskSearchIndex.class);
public DiskSearchIndex(DirectoryManager<V> dirMgr, IndexReaderDecorator<R> decorator,SearchIndexManager<R,V> idxMgr){
super(idxMgr, true);
_dirMgr = dirMgr;
_mergePolicyParams = new MergePolicyParams();
_dispenser = new IndexReaderDispenser<R,V>(_dirMgr, decorator,this);
_mergeScheduler = new SerialMergeScheduler();
_deletionPolicy = new ZoieIndexDeletionPolicy();
}
public V getVersion()
{
return _dispenser.getCurrentVersion();
}
public MergePolicyParams getMergePolicyParams(){
return _mergePolicyParams;
}
/**
* Gets the number of docs in the current loaded index
* @return number of docs
*/
public int getNumdocs()
{
IndexReader reader=_dispenser.getIndexReader();
if (reader!=null)
{
return reader.numDocs();
}
else
{
return 0;
}
}
public int getSegmentCount() throws IOException{
if (_dirMgr == null || !_dirMgr.exists()){
return 0;
}
Directory dir = null;
try{
dir = _dirMgr.getDirectory();
}
catch(Exception e){
return 0;
}
if (dir == null) return 0;
return IndexUtil.getNumSegments(dir);
}
public String getSegmentInfo()
{
if (_dirMgr == null || !_dirMgr.exists())
{
return "";
}
Directory dir = null;
try
{
dir = _dirMgr.getDirectory();
}
catch(Exception e)
{
return "";
}
if (dir == null) return "";
return IndexUtil.getSegmentsInfo(dir);
}
/**
* Close and releases dispenser and clean up
*/
public void close()
{
super.close();
// close the dispenser
if (_dispenser != null)
{
_dispenser.close();
}
}
/**
* Refreshes the index reader
*/
@Override
public void refresh()
{
synchronized(this)
{
try {
LongSet delDocs = _delDocs;
clearDeletes();
_dispenser.getNewReader();
markDeletes(delDocs); // re-mark deletes
commitDeletes();
} catch (IOException e) {
ZoieHealth.setFatal();
log.error(e.getMessage(),e);
}
}
}
@Override
protected void finalize()
{
close();
}
/**
* Opens an index modifier.
* @param analyzer Analyzer
* @return IndexModifer instance
*/
public IndexWriter openIndexWriter(Analyzer analyzer,Similarity similarity) throws IOException
{
if(_indexWriter != null) return _indexWriter;
Directory directory = _dirMgr.getDirectory(true);
log.info("opening index writer at: "+_dirMgr.getPath());
// create a new modifier to the index, assuming at most one instance is running at any given time
boolean create = !IndexReader.indexExists(directory);
// hao: autocommit is set to false with this constructor
IndexWriter idxWriter = new IndexWriter(directory, analyzer, create, _deletionPolicy, MaxFieldLength.UNLIMITED);
idxWriter.setMergeScheduler(_mergeScheduler);
ZoieMergePolicy mergePolicy = new ZoieMergePolicy(idxWriter);
mergePolicy.setMergePolicyParams(_mergePolicyParams);
idxWriter.setRAMBufferSizeMB(5);
idxWriter.setMergePolicy(mergePolicy);
if (similarity != null)
{
idxWriter.setSimilarity(similarity);
}
_indexWriter = idxWriter;
return idxWriter;
}
/**
* Gets the current reader
*/
public ZoieIndexReader<R> openIndexReader() throws IOException
{
// use dispenser to get the reader
return _dispenser.getIndexReader();
}
@Override
protected IndexReader openIndexReaderForDelete() throws IOException {
Directory directory = _dirMgr.getDirectory(true);
if (IndexReader.indexExists(directory)){
return IndexReader.open(directory, _deletionPolicy, false);
}
else{
return null;
}
}
/**
* Gets a new reader, force a reader refresh
* @return
* @throws IOException
*/
public ZoieIndexReader<R> getNewReader() throws IOException
{
synchronized(this)
{
refresh();
commitDeletes();
ZoieIndexReader<R> reader = _dispenser.getIndexReader();
return reader;
}
}
/**
* Writes the current version/SCN to the disk
*/
public void setVersion(V version) throws IOException
{
_dirMgr.setVersion(version);
}
public DiskIndexSnapshot getSnapshot() throws IOException
{
IndexSignature<V> sig = new IndexSignature<V>(_dirMgr.getVersion());
if(sig != null)
{
ZoieIndexDeletionPolicy.Snapshot snapshot = _deletionPolicy.getSnapshot();
if(snapshot != null)
{
return new DiskIndexSnapshot(_dirMgr, sig, snapshot);
}
}
return null;
}
public void importSnapshot(ReadableByteChannel channel) throws IOException
{
DiskIndexSnapshot.readSnapshot(channel, _dirMgr);
}
}