/*
* Copyright 2005 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;
namespace Lucene.Net.Search{
/// <summary>An alternative to BooleanScorer.
/// <br>Uses ConjunctionScorer, DisjunctionScorer, ReqOptScorer and ReqExclScorer.
/// <br>Implements skipTo(), and has no limitations on the numbers of added scorers.
/// </summary>
class BooleanScorer2 : Scorer
{
private class AnonymousClassDisjunctionSumScorer : DisjunctionSumScorer
{
private void InitBlock(BooleanScorer2 enclosingInstance)
{
this.enclosingInstance = enclosingInstance;
}
private BooleanScorer2 enclosingInstance;
public BooleanScorer2 Enclosing_Instance
{
get
{
return enclosingInstance;
}
}
internal AnonymousClassDisjunctionSumScorer(BooleanScorer2 enclosingInstance, System.Collections.IList Param1, int Param2):base(Param1, Param2)
{
InitBlock(enclosingInstance);
}
private int lastScoredDoc = - 1;
public override float Score()
{
if (Doc() > lastScoredDoc)
{
lastScoredDoc = Doc();
Enclosing_Instance.coordinator.nrMatchers += base.nrMatchers;
}
return base.Score();
}
}
private class AnonymousClassConjunctionScorer : ConjunctionScorer
{
private void InitBlock(int requiredNrMatchers, BooleanScorer2 enclosingInstance)
{
this.requiredNrMatchers = requiredNrMatchers;
this.enclosingInstance = enclosingInstance;
}
private int requiredNrMatchers;
private BooleanScorer2 enclosingInstance;
public BooleanScorer2 Enclosing_Instance
{
get
{
return enclosingInstance;
}
}
internal AnonymousClassConjunctionScorer(int requiredNrMatchers, BooleanScorer2 enclosingInstance, Lucene.Net.Search.Similarity Param1):base(Param1)
{
InitBlock(requiredNrMatchers, enclosingInstance);
}
private int lastScoredDoc = - 1;
public override float Score()
{
if (Doc() > lastScoredDoc)
{
lastScoredDoc = Doc();
Enclosing_Instance.coordinator.nrMatchers += requiredNrMatchers;
}
// All scorers match, so defaultSimilarity super.score() always has 1 as
// the coordination factor.
// Therefore the sum of the scores of the requiredScorers
// is used as score.
return base.Score();
}
}
private System.Collections.ArrayList requiredScorers = new System.Collections.ArrayList();
private System.Collections.ArrayList optionalScorers = new System.Collections.ArrayList();
private System.Collections.ArrayList prohibitedScorers = new System.Collections.ArrayList();
private class Coordinator
{
public Coordinator(BooleanScorer2 enclosingInstance)
{
InitBlock(enclosingInstance);
}
private void InitBlock(BooleanScorer2 enclosingInstance)
{
this.enclosingInstance = enclosingInstance;
}
private BooleanScorer2 enclosingInstance;
public BooleanScorer2 Enclosing_Instance
{
get
{
return enclosingInstance;
}
}
internal int maxCoord = 0; // to be increased for each non prohibited scorer
private float[] coordFactors = null;
internal virtual void Init()
{
// use after all scorers have been added.
coordFactors = new float[maxCoord + 1];
Similarity sim = Enclosing_Instance.GetSimilarity();
for (int i = 0; i <= maxCoord; i++)
{
coordFactors[i] = sim.Coord(i, maxCoord);
}
}
internal int nrMatchers; // to be increased by score() of match counting scorers.
internal virtual void InitDoc()
{
nrMatchers = 0;
}
internal virtual float CoordFactor()
{
return coordFactors[nrMatchers];
}
}
private Coordinator coordinator;
/// <summary>The scorer to which all scoring will be delegated,
/// except for computing and using the coordination factor.
/// </summary>
private Scorer countingSumScorer = null;
/// <summary>The number of optionalScorers that need to match (if there are any) </summary>
private int minNrShouldMatch;
/// <summary>Create a BooleanScorer2.</summary>
/// <param name="similarity">The similarity to be used.
/// </param>
/// <param name="minNrShouldMatch">The minimum number of optional added scorers
/// that should match during the search.
/// In case no required scorers are added,
/// at least one of the optional scorers will have to
/// match during the search.
/// </param>
public BooleanScorer2(Similarity similarity, int minNrShouldMatch):base(similarity)
{
if (minNrShouldMatch < 0)
{
throw new System.ArgumentException("Minimum number of optional scorers should not be negative");
}
coordinator = new Coordinator(this);
this.minNrShouldMatch = minNrShouldMatch;
}
/// <summary>Create a BooleanScorer2.
/// In no required scorers are added,
/// at least one of the optional scorers will have to match during the search.
/// </summary>
/// <param name="similarity">The similarity to be used.
/// </param>
public BooleanScorer2(Similarity similarity) : this(similarity, 0)
{
}
public virtual void Add(Scorer scorer, bool required, bool prohibited)
{
if (!prohibited)
{
coordinator.maxCoord++;
}
if (required)
{
if (prohibited)
{
throw new System.ArgumentException("scorer cannot be required and prohibited");
}
requiredScorers.Add(scorer);
}
else if (prohibited)
{
prohibitedScorers.Add(scorer);
}
else
{
optionalScorers.Add(scorer);
}
}
/// <summary>Initialize the match counting scorer that sums all the
/// scores. <p>
/// When "counting" is used in a name it means counting the number
/// of matching scorers.<br>
/// When "sum" is used in a name it means score value summing
/// over the matching scorers
/// </summary>
private void InitCountingSumScorer()
{
coordinator.Init();
countingSumScorer = MakeCountingSumScorer();
}
/// <summary>Count a scorer as a single match. </summary>
private class SingleMatchScorer : Scorer
{
private void InitBlock(BooleanScorer2 enclosingInstance)
{
this.enclosingInstance = enclosingInstance;
}
private BooleanScorer2 enclosingInstance;
public BooleanScorer2 Enclosing_Instance
{
get
{
return enclosingInstance;
}
}
private Scorer scorer;
private int lastScoredDoc = - 1;
internal SingleMatchScorer(BooleanScorer2 enclosingInstance, Scorer scorer) : base(scorer.GetSimilarity())
{
InitBlock(enclosingInstance);
this.scorer = scorer;
}
public override float Score()
{
if (Doc() > lastScoredDoc)
{
lastScoredDoc = Doc();
Enclosing_Instance.coordinator.nrMatchers++;
}
return scorer.Score();
}
public override int Doc()
{
return scorer.Doc();
}
public override bool Next()
{
return scorer.Next();
}
public override bool SkipTo(int docNr)
{
return scorer.SkipTo(docNr);
}
public override Explanation Explain(int docNr)
{
return scorer.Explain(docNr);
}
}
private Scorer CountingDisjunctionSumScorer(System.Collections.IList scorers, int minMrShouldMatch)
// each scorer from the list counted as a single matcher
{
return new AnonymousClassDisjunctionSumScorer(this, scorers, minMrShouldMatch);
}
private static Similarity defaultSimilarity = new DefaultSimilarity();
private Scorer CountingConjunctionSumScorer(System.Collections.IList requiredScorers)
{
// each scorer from the list counted as a single matcher
int requiredNrMatchers = requiredScorers.Count;
ConjunctionScorer cs = new AnonymousClassConjunctionScorer(requiredNrMatchers, this, defaultSimilarity);
System.Collections.IEnumerator rsi = requiredScorers.GetEnumerator();
while (rsi.MoveNext())
{
cs.Add((Scorer) rsi.Current);
}
return cs;
}
private Scorer DualConjunctionSumScorer(Scorer req1, Scorer req2)
{
// non counting.
//UPGRADE_NOTE: Final was removed from the declaration of 'requiredNrMatchers '. "ms-help://MS.VSCC.v80/dv_commoner/local/redirect.htm?index='!DefaultContextWindowIndex'&keyword='jlca1003'"
int requiredNrMatchers = requiredScorers.Count;
ConjunctionScorer cs = new ConjunctionScorer(defaultSimilarity);
// All scorers match, so defaultSimilarity super.score() always has 1 as
// the coordination factor.
// Therefore the sum of the scores of two scorers
// is used as score.
cs.Add(req1);
cs.Add(req2);
return cs;
}
/// <summary>Returns the scorer to be used for match counting and score summing.
/// Uses requiredScorers, optionalScorers and prohibitedScorers.
/// </summary>
private Scorer MakeCountingSumScorer()
{
// each scorer counted as a single matcher
return (requiredScorers.Count == 0)?MakeCountingSumScorerNoReq():MakeCountingSumScorerSomeReq();
}
private Scorer MakeCountingSumScorerNoReq()
{
// No required scorers
if (optionalScorers.Count == 0)
{
return new NonMatchingScorer(); // no clauses or only prohibited clauses
}
else
{
// No required scorers. At least one optional scorer.
// minNrShouldMatch optional scorers are required, but at least 1
int nrOptRequired = (minNrShouldMatch < 1)?1:minNrShouldMatch;
if (optionalScorers.Count < nrOptRequired)
{
return new NonMatchingScorer(); // fewer optional clauses than minimum (at least 1) that should match
}
else
{
// optionalScorers.size() >= nrOptRequired, no required scorers
Scorer requiredCountingSumScorer = (optionalScorers.Count > nrOptRequired)?CountingDisjunctionSumScorer(optionalScorers, nrOptRequired):((optionalScorers.Count == 1)?new SingleMatchScorer(this, (Scorer) optionalScorers[0]):CountingConjunctionSumScorer(optionalScorers));
return AddProhibitedScorers(requiredCountingSumScorer);
}
}
}
private Scorer MakeCountingSumScorerSomeReq()
{
// At least one required scorer.
if (optionalScorers.Count < minNrShouldMatch)
{
return new NonMatchingScorer(); // fewer optional clauses than minimum that should match
}
else if (optionalScorers.Count == minNrShouldMatch)
{
// all optional scorers also required.
System.Collections.ArrayList allReq = new System.Collections.ArrayList(requiredScorers);
allReq.AddRange(optionalScorers);
return AddProhibitedScorers(CountingConjunctionSumScorer(allReq));
}
else
{
// optionalScorers.size() > minNrShouldMatch, and at least one required scorer
Scorer requiredCountingSumScorer = (requiredScorers.Count == 1)?new SingleMatchScorer(this, (Scorer) requiredScorers[0]):CountingConjunctionSumScorer(requiredScorers);
if (minNrShouldMatch > 0)
{
// use a required disjunction scorer over the optional scorers
return AddProhibitedScorers(DualConjunctionSumScorer(requiredCountingSumScorer, CountingDisjunctionSumScorer(optionalScorers, minNrShouldMatch)));
}
else
{
// minNrShouldMatch == 0
return new ReqOptSumScorer(AddProhibitedScorers(requiredCountingSumScorer), ((optionalScorers.Count == 1)?new SingleMatchScorer(this, (Scorer) optionalScorers[0]):CountingDisjunctionSumScorer(optionalScorers, 1))); // require 1 in combined, optional scorer.
}
}
}
/// <summary>Returns the scorer to be used for match counting and score summing.
/// Uses the given required scorer and the prohibitedScorers.
/// </summary>
/// <param name="requiredCountingSumScorer">A required scorer already built.
/// </param>
private Scorer AddProhibitedScorers(Scorer requiredCountingSumScorer)
{
return (prohibitedScorers.Count == 0)?requiredCountingSumScorer:new ReqExclScorer(requiredCountingSumScorer, ((prohibitedScorers.Count == 1)?(Scorer) prohibitedScorers[0]:new DisjunctionSumScorer(prohibitedScorers)));
}
/// <summary>Scores and collects all matching documents.</summary>
/// <param name="hc">The collector to which all matching documents are passed through
/// {@link HitCollector#Collect(int, float)}.
/// <br>When this method is used the {@link #Explain(int)} method should not be used.
/// </param>
public override void Score(HitCollector hc)
{
if (countingSumScorer == null)
{
InitCountingSumScorer();
}
while (countingSumScorer.Next())
{
hc.Collect(countingSumScorer.Doc(), Score());
}
}
/// <summary>Expert: Collects matching documents in a range.
/// <br>Note that {@link #Next()} must be called once before this method is
/// called for the first time.
/// </summary>
/// <param name="hc">The collector to which all matching documents are passed through
/// {@link HitCollector#Collect(int, float)}.
/// </param>
/// <param name="max">Do not score documents past this.
/// </param>
/// <returns> true if more matching documents may remain.
/// </returns>
protected internal override bool Score(HitCollector hc, int max)
{
// null pointer exception when Next() was not called before:
int docNr = countingSumScorer.Doc();
while (docNr < max)
{
hc.Collect(docNr, Score());
if (!countingSumScorer.Next())
{
return false;
}
docNr = countingSumScorer.Doc();
}
return true;
}
public override int Doc()
{
return countingSumScorer.Doc();
}
public override bool Next()
{
if (countingSumScorer == null)
{
InitCountingSumScorer();
}
return countingSumScorer.Next();
}
public override float Score()
{
coordinator.InitDoc();
float sum = countingSumScorer.Score();
return sum * coordinator.CoordFactor();
}
/// <summary>Skips to the first match beyond the current whose document number is
/// greater than or equal to a given target.
///
/// <p>When this method is used the {@link #Explain(int)} method should not be used.
///
/// </summary>
/// <param name="target">The target document number.
/// </param>
/// <returns> true iff there is such a match.
/// </returns>
public override bool SkipTo(int target)
{
if (countingSumScorer == null)
{
InitCountingSumScorer();
}
return countingSumScorer.SkipTo(target);
}
/// <summary>Throws an UnsupportedOperationException.
/// TODO: Implement an explanation of the coordination factor.
/// </summary>
/// <param name="doc">The document number for the explanation.
/// </param>
/// <throws> UnsupportedOperationException </throws>
public override Explanation Explain(int doc)
{
throw new System.NotSupportedException();
/* How to explain the coordination factor?
initCountingSumScorer();
return countingSumScorer.explain(doc); // misses coord factor.
*/
}
}
}
|