/*
* 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 IndexReaderLucene.Net.Index.IndexReader;
using MultipleTermPositionsLucene.Net.Index.MultipleTermPositions;
using TermLucene.Net.Index.Term;
using TermPositionsLucene.Net.Index.TermPositions;
using ToStringUtilsLucene.Net.Util.ToStringUtils;
namespace Lucene.Net.Search{
/// <summary> MultiPhraseQuery is a generalized version of PhraseQuery, with an added
/// method {@link #Add(Term[])}.
/// To use this class, to search for the phrase "Microsoft app*" first use
/// add(Term) on the term "Microsoft", then find all terms that have "app" as
/// prefix using IndexReader.terms(Term), and use MultiPhraseQuery.add(Term[]
/// terms) to add them to the query.
///
/// </summary>
/// <author> Anders Nielsen
/// </author>
/// <version> 1.0
/// </version>
[Serializable]
public class MultiPhraseQuery : Query
{
private System.String field;
private System.Collections.ArrayList termArrays = new System.Collections.ArrayList();
private System.Collections.ArrayList positions = System.Collections.ArrayList.Synchronized(new System.Collections.ArrayList(10));
private int slop = 0;
/// <summary>Sets the phrase slop for this query.</summary>
/// <seealso cref="PhraseQuery.SetSlop(int)">
/// </seealso>
public virtual void SetSlop(int s)
{
slop = s;
}
/// <summary>Sets the phrase slop for this query.</summary>
/// <seealso cref="PhraseQuery.GetSlop()">
/// </seealso>
public virtual int GetSlop()
{
return slop;
}
/// <summary>Add a single term at the next position in the phrase.</summary>
/// <seealso cref="PhraseQuery.Add(Term)">
/// </seealso>
public virtual void Add(Term term)
{
Add(new Term[]{term});
}
/// <summary>Add multiple terms at the next position in the phrase. Any of the terms
/// may match.
///
/// </summary>
/// <seealso cref="PhraseQuery.Add(Term)">
/// </seealso>
public virtual void Add(Term[] terms)
{
int position = 0;
if (positions.Count > 0)
position = ((System.Int32) positions[positions.Count - 1]) + 1;
Add(terms, position);
}
/// <summary> Allows to specify the relative position of terms within the phrase.
///
/// </summary>
/// <seealso cref="PhraseQuery.Add(Term, int)">
/// </seealso>
/// <param name="terms">
/// </param>
/// <param name="position">
/// </param>
public virtual void Add(Term[] terms, int position)
{
if (termArrays.Count == 0)
field = terms[0].Field();
for (int i = 0; i < terms.Length; i++)
{
if ((System.Object) terms[i].Field() != (System.Object) field)
{
throw new System.ArgumentException("All phrase terms must be in the same field (" + field + "): " + terms[i]);
}
}
termArrays.Add(terms);
positions.Add((System.Int32) position);
}
/// <summary> Returns the relative positions of terms in this phrase.</summary>
public virtual int[] GetPositions()
{
int[] result = new int[positions.Count];
for (int i = 0; i < positions.Count; i++)
result[i] = ((System.Int32) positions[i]);
return result;
}
[Serializable]
private class MultiPhraseWeight : Weight
{
private void InitBlock(MultiPhraseQuery enclosingInstance)
{
this.enclosingInstance = enclosingInstance;
}
private MultiPhraseQuery enclosingInstance;
public MultiPhraseQuery Enclosing_Instance
{
get
{
return enclosingInstance;
}
}
private Similarity similarity;
private float value_Renamed;
private float idf;
private float queryNorm;
private float queryWeight;
public MultiPhraseWeight(MultiPhraseQuery enclosingInstance, Searcher searcher)
{
InitBlock(enclosingInstance);
this.similarity = Enclosing_Instance.GetSimilarity(searcher);
// compute idf
System.Collections.IEnumerator i = Enclosing_Instance.termArrays.GetEnumerator();
while (i.MoveNext())
{
Term[] terms = (Term[]) i.Current;
for (int j = 0; j < terms.Length; j++)
{
idf += Enclosing_Instance.GetSimilarity(searcher).Idf(terms[j], searcher);
}
}
}
public virtual Query GetQuery()
{
return 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)
{
if (Enclosing_Instance.termArrays.Count == 0)
// optimize zero-term case
return null;
TermPositions[] tps = new TermPositions[Enclosing_Instance.termArrays.Count];
for (int i = 0; i < tps.Length; i++)
{
Term[] terms = (Term[]) Enclosing_Instance.termArrays[i];
TermPositions p;
if (terms.Length > 1)
p = new MultipleTermPositions(reader, terms);
else
p = reader.TermPositions(terms[0]);
if (p == null)
return null;
tps[i] = p;
}
if (Enclosing_Instance.slop == 0)
return new ExactPhraseScorer(this, tps, Enclosing_Instance.GetPositions(), similarity, reader.Norms(Enclosing_Instance.field));
else
return new SloppyPhraseScorer(this, tps, Enclosing_Instance.GetPositions(), similarity, Enclosing_Instance.slop, reader.Norms(Enclosing_Instance.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(" + GetQuery() + ")");
// 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
Explanation fieldExpl = new Explanation();
fieldExpl.SetDescription("fieldWeight(" + GetQuery() + " in " + doc + "), product of:");
Explanation tfExpl = Scorer(reader).Explain(doc);
fieldExpl.AddDetail(tfExpl);
fieldExpl.AddDetail(idfExpl);
Explanation fieldNormExpl = new Explanation();
byte[] fieldNorms = reader.Norms(Enclosing_Instance.field);
float fieldNorm = fieldNorms != null ? Similarity.DecodeNorm(fieldNorms[doc]) : 0.0f;
fieldNormExpl.SetValue(fieldNorm);
fieldNormExpl.SetDescription("fieldNorm(field=" + Enclosing_Instance.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;
}
}
public override Query Rewrite(IndexReader reader)
{
if (termArrays.Count == 1)
{
// optimize one-term case
Term[] terms = (Term[]) termArrays[0];
BooleanQuery boq = new BooleanQuery(true);
for (int i = 0; i < terms.Length; i++)
{
boq.Add(new TermQuery(terms[i]), BooleanClause.Occur.SHOULD);
}
boq.SetBoost(GetBoost());
return boq;
}
else
{
return this;
}
}
protected internal override Weight CreateWeight(Searcher searcher)
{
return new MultiPhraseWeight(this, searcher);
}
/// <summary>Prints a user-readable version of this query. </summary>
public override System.String ToString(System.String f)
{
System.Text.StringBuilder buffer = new System.Text.StringBuilder();
if (!field.Equals(f))
{
buffer.Append(field);
buffer.Append(":");
}
buffer.Append("\"");
System.Collections.IEnumerator i = termArrays.GetEnumerator();
while (i.MoveNext())
{
Term[] terms = (Term[]) i.Current;
if (terms.Length > 1)
{
buffer.Append("(");
for (int j = 0; j < terms.Length; j++)
{
buffer.Append(terms[j].Text());
if (j < terms.Length - 1)
buffer.Append(" ");
}
buffer.Append(")");
}
else
{
buffer.Append(terms[0].Text());
}
if (i.MoveNext())
buffer.Append(" ");
}
buffer.Append("\"");
if (slop != 0)
{
buffer.Append("~");
buffer.Append(slop);
}
buffer.Append(ToStringUtils.Boost(GetBoost()));
return buffer.ToString();
}
// {{Aroush-1.9}} Do we need this?!
override public System.Object Clone()
{
return null;
}
}
}
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