/
NormValueSource.cs
110 lines (96 loc) · 3.75 KB
/
NormValueSource.cs
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// Lucene version compatibility level 4.8.1
using Lucene.Net.Index;
using Lucene.Net.Queries.Function.DocValues;
using Lucene.Net.Search;
using Lucene.Net.Search.Similarities;
using System;
using System.Collections;
namespace Lucene.Net.Queries.Function.ValueSources
{
/*
* 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>
/// Function that returns <see cref="TFIDFSimilarity.DecodeNormValue(long)"/>
/// for every document.
/// <para/>
/// Note that the configured Similarity for the field must be
/// a subclass of <see cref="TFIDFSimilarity"/>
/// @lucene.internal
/// </summary>
public class NormValueSource : ValueSource
{
protected readonly string m_field;
public NormValueSource(string field)
{
this.m_field = field;
}
public virtual string Name => "norm";
public override string GetDescription()
{
return Name + '(' + m_field + ')';
}
public override void CreateWeight(IDictionary context, IndexSearcher searcher)
{
context["searcher"] = searcher;
}
public override FunctionValues GetValues(IDictionary context, AtomicReaderContext readerContext)
{
var searcher = (IndexSearcher)context["searcher"];
TFIDFSimilarity similarity = IDFValueSource.AsTFIDF(searcher.Similarity, m_field);
if (similarity is null)
{
throw UnsupportedOperationException.Create("requires a TFIDFSimilarity (such as DefaultSimilarity)");
}
NumericDocValues norms = readerContext.AtomicReader.GetNormValues(m_field);
if (norms is null)
{
return new ConstDoubleDocValues(0.0, this);
}
return new SingleDocValuesAnonymousClass(this, similarity, norms);
}
private class SingleDocValuesAnonymousClass : SingleDocValues
{
private readonly TFIDFSimilarity similarity;
private readonly NumericDocValues norms;
public SingleDocValuesAnonymousClass(NormValueSource @this, TFIDFSimilarity similarity, NumericDocValues norms)
: base(@this)
{
this.similarity = similarity;
this.norms = norms;
}
/// <summary>
/// NOTE: This was floatVal() in Lucene
/// </summary>
public override float SingleVal(int doc)
{
return similarity.DecodeNormValue(norms.Get(doc));
}
}
public override bool Equals(object o)
{
if (this.GetType() != o.GetType())
{
return false;
}
return this.m_field.Equals(((NormValueSource)o).m_field, StringComparison.Ordinal);
}
public override int GetHashCode()
{
return this.GetType().GetHashCode() + m_field.GetHashCode();
}
}
}