/*
* 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.exoplatform.services.jcr.impl.core.query.lucene;
import org.apache.lucene.index.IndexReader;
import org.apache.lucene.search.DocIdSetIterator;
import org.apache.lucene.search.IndexSearcher;
import org.apache.lucene.search.Query;
import org.apache.lucene.search.Scorer;
import java.io.IOException;
/**
* Wraps a lucene query result and adds a close method that allows to release
* resources after a query has been executed and the results have been read
* completely.
*/
public class LuceneQueryHits implements QueryHits
{
/**
* The IndexReader in use by the lucene hits.
*/
private final IndexReader reader;
/**
* The scorer for the query.
*/
private final Scorer scorer;
/**
* Release IndexReader on LuceneQueryHits.close().
*/
private final boolean releaseReaderOnClose;
public LuceneQueryHits(IndexReader reader, IndexSearcher searcher, Query query) throws IOException
{
this(reader, searcher, query, false);
}
/**
* Constructor.
*
* @param reader IndexReader
* @param searcher IndexSearcher
* @param query Query
* @param releaseReaderOnClose - release IndexReader on LuceneQueryHits.close().
* @throws IOException
*/
public LuceneQueryHits(IndexReader reader, IndexSearcher searcher, Query query, boolean releaseReaderOnClose)
throws IOException
{
this.reader = reader;
this.scorer = query.weight(searcher).scorer(reader, true, false);
this.releaseReaderOnClose = releaseReaderOnClose;
}
/**
* {@inheritDoc}
*/
public ScoreNode nextScoreNode() throws IOException
{
if (scorer == null)
{
return null;
}
int doc = scorer.nextDoc();
if (doc == DocIdSetIterator.NO_MORE_DOCS)
{
return null;
}
String uuid = reader.document(doc).get(FieldNames.UUID);
return new ScoreNode(uuid, scorer.score(), doc);
}
/**
* {@inheritDoc}
*/
public void close() throws IOException
{
if (scorer != null)
{
// make sure scorer frees resources
scorer.advance(Integer.MAX_VALUE);
}
if (releaseReaderOnClose && reader != null && reader instanceof ReleaseableIndexReader)
{
((ReleaseableIndexReader)reader).release();
}
}
/**
* @return always -1.
*/
public int getSize()
{
return -1;
}
/**
* {@inheritDoc}
*/
public void skip(int n) throws IOException
{
while (n-- > 0)
{
if (nextScoreNode() == null)
{
return;
}
}
}
}