| using Lucene.Net.Index; |
| using Lucene.Net.Search; |
| using System; |
| using System.Collections.Generic; |
| |
| namespace Lucene.Net.Expressions |
| { |
| /* |
| * 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="Lucene.Net.Search.Rescorer"/> that uses an expression to re-score |
| /// first pass hits. Functionally this is the same as |
| /// <see cref="Lucene.Net.Search.SortRescorer"/> (if you build the |
| /// <see cref="Lucene.Net.Search.Sort"/> using |
| /// <see cref="Expression.GetSortField(Bindings, bool)"/>), except for the <see cref="Explain"/> method |
| /// which gives more detail by showing the value of each |
| /// variable. |
| /// @lucene.experimental |
| /// </summary> |
| internal class ExpressionRescorer : SortRescorer |
| { |
| private readonly Expression expression; |
| private readonly Bindings bindings; |
| |
| /// <summary> |
| /// Uses the provided <see cref="Lucene.Net.Queries.Function.ValueSource"/> to assign second |
| /// pass scores. |
| /// </summary> |
| public ExpressionRescorer(Expression expression, Bindings bindings) |
| : base(new Sort(expression.GetSortField(bindings, true))) |
| { |
| this.expression = expression; |
| this.bindings = bindings; |
| } |
| |
| private class FakeScorer : Scorer |
| { |
| internal float score; |
| internal int doc = -1; |
| internal int freq = 1; |
| |
| public FakeScorer() |
| : base(null) |
| { |
| } |
| |
| public override int Advance(int target) |
| { |
| throw new NotSupportedException("FakeScorer doesn't support Advance(int)"); |
| } |
| |
| public override int DocID => doc; |
| |
| public override int Freq => freq; |
| |
| public override int NextDoc() |
| { |
| throw new NotSupportedException("FakeScorer doesn't support NextDoc()"); |
| } |
| |
| public override float GetScore() |
| { |
| return score; |
| } |
| |
| public override long GetCost() |
| { |
| return 1; |
| } |
| |
| public override Weight Weight => throw new NotSupportedException(); |
| |
| public override ICollection<Scorer.ChildScorer> GetChildren() |
| { |
| throw new NotSupportedException(); |
| } |
| } |
| |
| |
| public override Explanation Explain(IndexSearcher searcher, Explanation firstPassExplanation, int docID) |
| { |
| Explanation result = base.Explain(searcher, firstPassExplanation, docID); |
| IList<AtomicReaderContext> leaves = searcher.IndexReader.Leaves; |
| int subReader = ReaderUtil.SubIndex(docID, leaves); |
| AtomicReaderContext readerContext = leaves[subReader]; |
| int docIDInSegment = docID - readerContext.DocBase; |
| var context = new Dictionary<string, object>(); |
| var fakeScorer = new FakeScorer { score = firstPassExplanation.Value, doc = docIDInSegment }; |
| context["scorer"] = fakeScorer; |
| foreach (string variable in expression.Variables) |
| { |
| result.AddDetail(new Explanation((float)bindings.GetValueSource(variable).GetValues |
| (context, readerContext).DoubleVal(docIDInSegment), "variable \"" + variable + "\"" |
| )); |
| } |
| return result; |
| } |
| } |
| } |