| using System.Collections.Generic; |
| |
| namespace Lucene.Net.Search |
| { |
| /* |
| * 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. |
| */ |
| |
| /// <summary> |
| /// A <see cref="Scorer"/> which wraps another scorer and caches the score of the |
| /// current document. Successive calls to <see cref="GetScore()"/> will return the same |
| /// result and will not invoke the wrapped Scorer's GetScore() method, unless the |
| /// current document has changed. |
| /// <para/> |
| /// This class might be useful due to the changes done to the <see cref="ICollector"/> |
| /// 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 <see cref="Scorer"/> object, and |
| /// might end up computing the score of a document more than once. |
| /// </summary> |
| public class ScoreCachingWrappingScorer : Scorer |
| { |
| private readonly Scorer scorer; |
| private int curDoc = -1; |
| private float curScore; |
| |
| /// <summary> |
| /// Creates a new instance by wrapping the given scorer. </summary> |
| public ScoreCachingWrappingScorer(Scorer scorer) |
| : base(scorer.m_weight) |
| { |
| this.scorer = scorer; |
| } |
| |
| public override float GetScore() |
| { |
| int doc = scorer.DocID; |
| if (doc != curDoc) |
| { |
| curScore = scorer.GetScore(); |
| curDoc = doc; |
| } |
| |
| return curScore; |
| } |
| |
| public override int Freq => scorer.Freq; |
| |
| public override int DocID => scorer.DocID; |
| |
| public override int NextDoc() |
| { |
| return scorer.NextDoc(); |
| } |
| |
| public override int Advance(int target) |
| { |
| return scorer.Advance(target); |
| } |
| |
| public override ICollection<ChildScorer> GetChildren() |
| { |
| return new[] { new ChildScorer(scorer, "CACHED") }; |
| } |
| |
| public override long GetCost() |
| { |
| return scorer.GetCost(); |
| } |
| } |
| } |