/*
* 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.
*/
using System;
using IndexReader = Lucene.Net.Index.IndexReader;
using TermDocs = Lucene.Net.Index.TermDocs;
using ToStringUtils = Lucene.Net.Util.ToStringUtils;
using Lucene.Net.Search;
namespace Lucene.Net.Search.Function
{
/// Expert: A Query that sets the scores of document to the
/// values obtained from a {@link Lucene.Net.Search.Function.ValueSource ValueSource}.
///
/// This query provides a score for each and every undeleted document in the index.
///
/// The value source can be based on a (cached) value of an indexed field, but it
/// can also be based on an external source, e.g. values read from an external database.
///
/// Score is set as: Score(doc,query) = query.getBoost()2 * valueSource(doc).
///
///
/// WARNING: The status of the Search.Function package is experimental.
/// The APIs introduced here might change in the future and will not be
/// supported anymore in such a case.
///
[Serializable]
public class ValueSourceQuery:Query
{
internal ValueSource valSrc;
/// Create a value source query
/// provides the values defines the function to be used for scoring
///
public ValueSourceQuery(ValueSource valSrc)
{
this.valSrc = valSrc;
}
/*(non-Javadoc) @see Lucene.Net.Search.Query#rewrite(Lucene.Net.Index.IndexReader) */
public override Query Rewrite(IndexReader reader)
{
return this;
}
/*(non-Javadoc) @see Lucene.Net.Search.Query#extractTerms(java.util.Set) */
public override void ExtractTerms(System.Collections.Hashtable terms)
{
// no terms involved here
}
[Serializable]
internal class ValueSourceWeight:Weight
{
private void InitBlock(ValueSourceQuery enclosingInstance)
{
this.enclosingInstance = enclosingInstance;
}
private ValueSourceQuery enclosingInstance;
public ValueSourceQuery Enclosing_Instance
{
get
{
return enclosingInstance;
}
}
internal Similarity similarity;
internal float queryNorm;
internal float queryWeight;
public ValueSourceWeight(ValueSourceQuery enclosingInstance, Searcher searcher)
{
InitBlock(enclosingInstance);
this.similarity = Enclosing_Instance.GetSimilarity(searcher);
}
/*(non-Javadoc) @see Lucene.Net.Search.Weight#getQuery() */
public override Query GetQuery()
{
return Enclosing_Instance;
}
/*(non-Javadoc) @see Lucene.Net.Search.Weight#getValue() */
public override float GetValue()
{
return queryWeight;
}
/*(non-Javadoc) @see Lucene.Net.Search.Weight#sumOfSquaredWeights() */
public override float SumOfSquaredWeights()
{
queryWeight = Enclosing_Instance.GetBoost();
return queryWeight * queryWeight;
}
/*(non-Javadoc) @see Lucene.Net.Search.Weight#normalize(float) */
public override void Normalize(float norm)
{
this.queryNorm = norm;
queryWeight *= this.queryNorm;
}
public override Scorer Scorer(IndexReader reader, bool scoreDocsInOrder, bool topScorer)
{
return new ValueSourceScorer(enclosingInstance, similarity, reader, this);
}
/*(non-Javadoc) @see Lucene.Net.Search.Weight#explain(Lucene.Net.Index.IndexReader, int) */
public override Explanation Explain(IndexReader reader, int doc)
{
return new ValueSourceScorer(enclosingInstance, similarity, reader, this).Explain(doc);
}
}
/// A scorer that (simply) matches all documents, and scores each document with
/// the value of the value soure in effect. As an example, if the value source
/// is a (cached) field source, then value of that field in that document will
/// be used. (assuming field is indexed for this doc, with a single token.)
///
private class ValueSourceScorer:Scorer
{
private void InitBlock(ValueSourceQuery enclosingInstance)
{
this.enclosingInstance = enclosingInstance;
}
private ValueSourceQuery enclosingInstance;
public ValueSourceQuery Enclosing_Instance
{
get
{
return enclosingInstance;
}
}
private ValueSourceWeight weight;
private float qWeight;
private DocValues vals;
private TermDocs termDocs;
private int doc = - 1;
// constructor
internal ValueSourceScorer(ValueSourceQuery enclosingInstance, Similarity similarity, IndexReader reader, ValueSourceWeight w):base(similarity)
{
InitBlock(enclosingInstance);
this.weight = w;
this.qWeight = w.GetValue();
// this is when/where the values are first created.
vals = Enclosing_Instance.valSrc.GetValues(reader);
termDocs = reader.TermDocs(null);
}
/// use {@link #NextDoc()} instead.
///
[Obsolete("use NextDoc() instead. ")]
public override bool Next()
{
return termDocs.Next();
}
public override int NextDoc()
{
return doc = termDocs.Next()?termDocs.Doc():NO_MORE_DOCS;
}
/// use {@link #DocID()} instead.
///
[Obsolete("use DocID() instead.")]
public override int Doc()
{
return termDocs.Doc();
}
public override int DocID()
{
return doc;
}
/*(non-Javadoc) @see Lucene.Net.Search.Scorer#score() */
public override float Score()
{
return qWeight * vals.FloatVal(termDocs.Doc());
}
/// use {@link #Advance(int)} instead.
///
[Obsolete("use Advance(int)} instead.")]
public override bool SkipTo(int target)
{
return termDocs.SkipTo(target);
}
public override int Advance(int target)
{
return doc = termDocs.SkipTo(target)?termDocs.Doc():NO_MORE_DOCS;
}
/*(non-Javadoc) @see Lucene.Net.Search.Scorer#explain(int) */
public override Explanation Explain(int doc)
{
float sc = qWeight * vals.FloatVal(doc);
Explanation result = new ComplexExplanation(true, sc, Enclosing_Instance.ToString() + ", product of:");
result.AddDetail(vals.Explain(doc));
result.AddDetail(new Explanation(Enclosing_Instance.GetBoost(), "boost"));
result.AddDetail(new Explanation(weight.queryNorm, "queryNorm"));
return result;
}
}
public override Weight CreateWeight(Searcher searcher)
{
return new ValueSourceQuery.ValueSourceWeight(this, searcher);
}
public override System.String ToString(System.String field)
{
return valSrc.ToString() + ToStringUtils.Boost(GetBoost());
}
/// Returns true if o
is equal to this.
public override bool Equals(System.Object o)
{
if (GetType() != o.GetType())
{
return false;
}
ValueSourceQuery other = (ValueSourceQuery) o;
return this.GetBoost() == other.GetBoost() && this.valSrc.Equals(other.valSrc);
}
/// Returns a hash code value for this object.
public override int GetHashCode()
{
return (GetType().GetHashCode() + valSrc.GetHashCode()) ^ BitConverter.ToInt32(BitConverter.GetBytes(GetBoost()), 0);
}
override public System.Object Clone()
{
return this.MemberwiseClone();
}
public ValueSource valSrc_ForNUnit
{
get { return valSrc; }
}
}
}