/*
* 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 Lucene.Net.Index;
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 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) 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) 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.Value;
// this is when/where the values are first created.
vals = Enclosing_Instance.valSrc.GetValues(reader);
termDocs = reader.TermDocs(null);
}
public override int NextDoc()
{
return doc = termDocs.Next() ? termDocs.Doc : NO_MORE_DOCS;
}
public override int DocID()
{
return doc;
}
public override int Advance(int target)
{
return doc = termDocs.SkipTo(target) ? termDocs.Doc : NO_MORE_DOCS;
}
/*(non-Javadoc)