/* * Copyright 2004 The Apache Software Foundation * * Licensed 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; using IndexReader = Lucene.Net.Index.IndexReader; using Term = Lucene.Net.Index.Term; using TermDocs = Lucene.Net.Index.TermDocs; namespace Lucene.Net.Search { /// A Query that matches documents containing a term. /// This may be combined with other terms with a {@link BooleanQuery}. /// [Serializable] public class TermQuery : Query { private Term term; [Serializable] private class TermWeight : Weight { private void InitBlock(TermQuery enclosingInstance) { this.enclosingInstance = enclosingInstance; } private TermQuery enclosingInstance; virtual public Query GetQuery() { return Enclosing_Instance; } public TermQuery Enclosing_Instance { get { return enclosingInstance; } } private Similarity similarity; private Searcher searcher; private float value_Renamed; private float idf; private float queryNorm; private float queryWeight; public TermWeight(TermQuery enclosingInstance, Searcher searcher) { InitBlock(enclosingInstance); this.similarity = Enclosing_Instance.GetSimilarity(searcher); idf = similarity.Idf(Enclosing_Instance.term, searcher); // compute idf } public override System.String ToString() { return "weight(" + Enclosing_Instance + ")"; } public virtual float GetValue() { return value_Renamed; } public virtual float SumOfSquaredWeights() { queryWeight = idf * Enclosing_Instance.GetBoost(); // compute query weight return queryWeight * queryWeight; // square it } public virtual void Normalize(float queryNorm) { this.queryNorm = queryNorm; queryWeight *= queryNorm; // normalize query weight value_Renamed = queryWeight * idf; // idf for document } public virtual Scorer Scorer(IndexReader reader) { TermDocs termDocs = reader.TermDocs(Enclosing_Instance.term); if (termDocs == null) return null; return new TermScorer(this, termDocs, similarity, reader.Norms(Enclosing_Instance.term.Field())); } public virtual Explanation Explain(IndexReader reader, int doc) { Explanation result = new Explanation(); result.SetDescription("weight(" + GetQuery() + " in " + doc + "), product of:"); Explanation idfExpl = new Explanation(idf, "idf(docFreq=" + reader.DocFreq(Enclosing_Instance.term) + ")"); // explain query weight Explanation queryExpl = new Explanation(); queryExpl.SetDescription("queryWeight(" + GetQuery() + "), product of:"); Explanation boostExpl = new Explanation(Enclosing_Instance.GetBoost(), "boost"); if (Enclosing_Instance.GetBoost() != 1.0f) queryExpl.AddDetail(boostExpl); queryExpl.AddDetail(idfExpl); Explanation queryNormExpl = new Explanation(queryNorm, "queryNorm"); queryExpl.AddDetail(queryNormExpl); queryExpl.SetValue(boostExpl.GetValue() * idfExpl.GetValue() * queryNormExpl.GetValue()); result.AddDetail(queryExpl); // explain Field weight System.String field = Enclosing_Instance.term.Field(); Explanation fieldExpl = new Explanation(); fieldExpl.SetDescription("fieldWeight(" + Enclosing_Instance.term + " in " + doc + "), product of:"); Explanation tfExpl = Scorer(reader).Explain(doc); fieldExpl.AddDetail(tfExpl); fieldExpl.AddDetail(idfExpl); Explanation fieldNormExpl = new Explanation(); byte[] fieldNorms = reader.Norms(field); float fieldNorm = fieldNorms != null?Similarity.DecodeNorm(fieldNorms[doc]):0.0f; fieldNormExpl.SetValue(fieldNorm); fieldNormExpl.SetDescription("fieldNorm(Field=" + field + ", doc=" + doc + ")"); fieldExpl.AddDetail(fieldNormExpl); fieldExpl.SetValue(tfExpl.GetValue() * idfExpl.GetValue() * fieldNormExpl.GetValue()); result.AddDetail(fieldExpl); // combine them result.SetValue(queryExpl.GetValue() * fieldExpl.GetValue()); if (queryExpl.GetValue() == 1.0f) return fieldExpl; return result; } } /// Constructs a query for the term t. public TermQuery(Term t) { term = t; } /// Returns the term of this query. public virtual Term GetTerm() { return term; } protected internal override Weight CreateWeight(Searcher searcher) { return new TermWeight(this, searcher); } public override void ExtractTerms(System.Collections.Hashtable terms) { Term term = GetTerm(); terms.Add(term, term); } /// Prints a user-readable version of this query. public override System.String ToString(System.String field) { System.Text.StringBuilder buffer = new System.Text.StringBuilder(); if (!term.Field().Equals(field)) { buffer.Append(term.Field()); buffer.Append(":"); } buffer.Append(term.Text()); if (GetBoost() != 1.0f) { System.Globalization.NumberFormatInfo nfi = new System.Globalization.CultureInfo("en-US", false).NumberFormat; nfi.NumberDecimalDigits = 1; buffer.Append("^"); buffer.Append(GetBoost().ToString("N", nfi)); //buffer.Append("^"); //buffer.Append(GetBoost().ToString()); } return buffer.ToString(); } /// Returns true iff o is equal to this. public override bool Equals(System.Object o) { if (!(o is TermQuery)) return false; TermQuery other = (TermQuery) o; return (this.GetBoost() == other.GetBoost()) && this.term.Equals(other.term); } /// Returns a hash code value for this object. public override int GetHashCode() { return BitConverter.ToInt32(BitConverter.GetBytes(GetBoost()), 0) ^ term.GetHashCode(); } } }