/*
* 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.
*/
using System;
namespace Lucene.Net.Search
{
/// A which wraps another scorer and caches the score of the
/// current document. Successive calls to will return the same
/// result and will not invoke the wrapped Scorer's score() method, unless the
/// current document has changed.
/// This class might be useful due to the changes done to the
/// interface, in which the score is not computed for a document by default, only
/// if the collector requests it. Some collectors may need to use the score in
/// several places, however all they have in hand is a object, and
/// might end up computing the score of a document more than once.
///
public class ScoreCachingWrappingScorer:Scorer
{
private Scorer scorer;
private int curDoc = - 1;
private float curScore;
/// Creates a new instance by wrapping the given scorer.
public ScoreCachingWrappingScorer(Scorer scorer):base(scorer.Similarity)
{
this.scorer = scorer;
}
public /*protected internal*/ override bool Score(Collector collector, int max, int firstDocID)
{
return scorer.Score(collector, max, firstDocID);
}
public override Similarity Similarity
{
get { return scorer.Similarity; }
}
public override float Score()
{
int doc = scorer.DocID();
if (doc != curDoc)
{
curScore = scorer.Score();
curDoc = doc;
}
return curScore;
}
public override int DocID()
{
return scorer.DocID();
}
public override int NextDoc()
{
return scorer.NextDoc();
}
public override void Score(Collector collector)
{
scorer.Score(collector);
}
public override int Advance(int target)
{
return scorer.Advance(target);
}
}
}