/**
* Copyright (c) 2002-2011 "Neo Technology,"
* Network Engine for Objects in Lund AB [http://neotechnology.com]
*
* This file is part of Neo4j.
*
* Neo4j is free software: you can redistribute it and/or modify
* it under the terms of the GNU Affero General Public License as
* published by the Free Software Foundation, either version 3 of the
* License, or (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU Affero General Public License for more details.
*
* You should have received a copy of the GNU Affero General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
package org.neo4j.index.impl.lucene;
import java.io.IOException;
import java.util.Iterator;
import org.apache.lucene.document.Document;
import org.apache.lucene.search.Query;
import org.apache.lucene.search.ScoreDoc;
import org.apache.lucene.search.Searcher;
import org.apache.lucene.search.Sort;
import org.apache.lucene.search.TopDocs;
import org.apache.lucene.search.TopFieldCollector;
import org.neo4j.helpers.collection.ArrayIterator;
import org.neo4j.index.lucene.QueryContext;
class TopDocsIterator extends AbstractIndexHits<Document>
{
private final Iterator<ScoreDoc> iterator;
private ScoreDoc currentDoc;
private final int size;
private final Searcher searcher;
TopDocsIterator( Query query, QueryContext context, Searcher searcher ) throws IOException
{
TopDocs docs = toTopDocs( query, context, searcher );
this.size = docs.scoreDocs.length;
this.iterator = new ArrayIterator<ScoreDoc>( docs.scoreDocs );
this.searcher = searcher;
}
private TopDocs toTopDocs( Query query, QueryContext context, Searcher searcher ) throws IOException
{
Sort sorting = context != null ? context.getSorting() : null;
TopDocs topDocs = null;
if ( sorting == null )
{
topDocs = searcher.search( query, context.getTop() );
}
else
{
boolean forceScore = context == null || !context.getTradeCorrectnessForSpeed();
if ( forceScore )
{
TopFieldCollector collector = LuceneDataSource.scoringCollector( sorting, context.getTop() );
searcher.search( query, collector );
topDocs = collector.topDocs();
}
else
{
topDocs = searcher.search( query, null, context.getTop(), sorting );
}
}
return topDocs;
}
@Override
protected Document fetchNextOrNull()
{
if ( !iterator.hasNext() )
{
return null;
}
currentDoc = iterator.next();
try
{
return searcher.doc( currentDoc.doc );
}
catch ( IOException e )
{
throw new RuntimeException( e );
}
}
public float currentScore()
{
return currentDoc.score;
}
public int size()
{
return this.size;
}
}