/*
* 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 PriorityQueueLucene.Net.Util.PriorityQueue;
namespace Lucene.Net.Search{
/// <summary> Expert: A hit queue for sorting by hits by terms in more than one field.
/// Uses <code>FieldCache.DEFAULT</code> for maintaining internal term lookup tables.
///
/// <p>Created: Dec 8, 2003 12:56:03 PM
///
/// </summary>
/// <author> Tim Jones (Nacimiento Software)
/// </author>
/// <since> lucene 1.4
/// </since>
/// <version> $Id: FieldSortedHitQueue.java 354819 2005-12-07 17:48:37Z yonik $
/// </version>
/// <seealso cref="Searcher.Search(Query,Filter,int,Sort)">
/// </seealso>
/// <seealso cref="FieldCache">
/// </seealso>
class FieldSortedHitQueue : PriorityQueue
{
private class AnonymousClassScoreDocComparator : ScoreDocComparator
{
public AnonymousClassScoreDocComparator(int[] fieldOrder)
{
InitBlock(fieldOrder);
}
private void InitBlock(int[] fieldOrder)
{
this.fieldOrder = fieldOrder;
}
private int[] fieldOrder;
public int Compare(ScoreDoc i, ScoreDoc j)
{
int fi = fieldOrder[i.doc];
int fj = fieldOrder[j.doc];
if (fi < fj)
return - 1;
if (fi > fj)
return 1;
return 0;
}
public virtual System.IComparable SortValue(ScoreDoc i)
{
return (System.Int32) fieldOrder[i.doc];
}
public virtual int SortType()
{
return SortField.INT;
}
}
private class AnonymousClassScoreDocComparator1 : ScoreDocComparator
{
public AnonymousClassScoreDocComparator1(float[] fieldOrder)
{
InitBlock(fieldOrder);
}
private void InitBlock(float[] fieldOrder)
{
this.fieldOrder = fieldOrder;
}
private float[] fieldOrder;
public int Compare(ScoreDoc i, ScoreDoc j)
{
float fi = fieldOrder[i.doc];
float fj = fieldOrder[j.doc];
if (fi < fj)
return - 1;
if (fi > fj)
return 1;
return 0;
}
public virtual System.IComparable SortValue(ScoreDoc i)
{
return (float) fieldOrder[i.doc];
}
public virtual int SortType()
{
return SortField.FLOAT;
}
}
private class AnonymousClassScoreDocComparator2 : ScoreDocComparator
{
public AnonymousClassScoreDocComparator2(Lucene.Net.Search.StringIndex index)
{
InitBlock(index);
}
private void InitBlock(Lucene.Net.Search.StringIndex index)
{
this.index = index;
}
private Lucene.Net.Search.StringIndex index;
public int Compare(ScoreDoc i, ScoreDoc j)
{
int fi = index.order[i.doc];
int fj = index.order[j.doc];
if (fi < fj)
return - 1;
if (fi > fj)
return 1;
return 0;
}
public virtual System.IComparable SortValue(ScoreDoc i)
{
return index.lookup[index.order[i.doc]];
}
public virtual int SortType()
{
return SortField.STRING;
}
}
private class AnonymousClassScoreDocComparator3 : ScoreDocComparator
{
public AnonymousClassScoreDocComparator3(System.Globalization.CompareInfo collator, System.String[] index)
{
InitBlock(collator, index);
}
private void InitBlock(System.Globalization.CompareInfo collator, System.String[] index)
{
this.collator = collator;
this.index = index;
}
private System.Globalization.CompareInfo collator;
private System.String[] index;
public int Compare(ScoreDoc i, ScoreDoc j)
{
return collator.Compare(index[i.doc].ToString(), index[j.doc].ToString());
}
public virtual System.IComparable SortValue(ScoreDoc i)
{
return index[i.doc];
}
public virtual int SortType()
{
return SortField.STRING;
}
}
/// <summary> Creates a hit queue sorted by the given list of fields.</summary>
/// <param name="reader"> Index to use.
/// </param>
/// <param name="fields">Field names, in priority order (highest priority first). Cannot be <code>null</code> or empty.
/// </param>
/// <param name="size"> The number of hits to retain. Must be greater than zero.
/// </param>
/// <throws> IOException </throws>
internal FieldSortedHitQueue(IndexReader reader, SortField[] fields, int size)
{
int n = fields.Length;
comparators = new ScoreDocComparator[n];
this.fields = new SortField[n];
for (int i = 0; i < n; ++i)
{
System.String fieldname = fields[i].GetField();
comparators[i] = GetCachedComparator(reader, fieldname, fields[i].GetType(), fields[i].GetLocale(), fields[i].GetFactory());
this.fields[i] = new SortField(fieldname, comparators[i].SortType(), fields[i].GetReverse());
}
Initialize(size);
}
/// <summary>Stores a comparator corresponding to each field being sorted by </summary>
protected internal ScoreDocComparator[] comparators;
/// <summary>Stores the sort criteria being used. </summary>
protected internal SortField[] fields;
/// <summary>Stores the maximum score value encountered, needed for normalizing. </summary>
protected internal float maxscore = System.Single.NegativeInfinity;
/// <summary>returns the maximum score encountered by elements inserted via insert()</summary>
public virtual float GetMaxScore()
{
return maxscore;
}
// The signature of this method takes a FieldDoc in order to avoid
// the unneeded cast to retrieve the score.
// inherit javadoc
public virtual bool Insert(FieldDoc fdoc)
{
maxscore = System.Math.Max(maxscore, fdoc.score);
return base.Insert(fdoc);
}
// This overrides PriorityQueue.insert() so that insert(FieldDoc) that
// keeps track of the score isn't accidentally bypassed.
// inherit javadoc
public override bool Insert(System.Object fdoc)
{
return Insert((FieldDoc) fdoc);
}
/// <summary> Returns whether <code>a</code> is less relevant than <code>b</code>.</summary>
/// <param name="a">ScoreDoc
/// </param>
/// <param name="b">ScoreDoc
/// </param>
/// <returns> <code>true</code> if document <code>a</code> should be sorted after document <code>b</code>.
/// </returns>
public override bool LessThan(System.Object a, System.Object b)
{
ScoreDoc docA = (ScoreDoc) a;
ScoreDoc docB = (ScoreDoc) b;
// run comparators
int n = comparators.Length;
int c = 0;
for (int i = 0; i < n && c == 0; ++i)
{
c = (fields[i].reverse)?comparators[i].Compare(docB, docA):comparators[i].Compare(docA, docB);
}
// avoid random sort order that could lead to duplicates (bug #31241):
if (c == 0)
return docA.doc > docB.doc;
return c > 0;
}
/// <summary> Given a FieldDoc object, stores the values used
/// to sort the given document. These values are not the raw
/// values out of the index, but the internal representation
/// of them. This is so the given search hit can be collated
/// by a MultiSearcher with other search hits.
/// </summary>
/// <param name="doc"> The FieldDoc to store sort values into.
/// </param>
/// <returns> The same FieldDoc passed in.
/// </returns>
/// <seealso cref="Searchable.Search(Weight,Filter,int,Sort)">
/// </seealso>
internal virtual FieldDoc FillFields(FieldDoc doc)
{
int n = comparators.Length;
System.IComparable[] fields = new System.IComparable[n];
for (int i = 0; i < n; ++i)
fields[i] = comparators[i].SortValue(doc);
doc.fields = fields;
//if (maxscore > 1.0f) doc.score /= maxscore; // normalize scores
return doc;
}
/// <summary>Returns the SortFields being used by this hit queue. </summary>
internal virtual SortField[] GetFields()
{
return fields;
}
/// <summary>Internal cache of comparators. Similar to FieldCache, only
/// caches comparators instead of term values.
/// </summary>
internal static readonly System.Collections.IDictionary Comparators = new System.Collections.Hashtable();
/// <summary>Returns a comparator if it is in the cache. </summary>
internal static ScoreDocComparator Lookup(IndexReader reader, System.String field, int type, System.Object factory)
{
FieldCacheImpl.Entry entry = (factory != null) ? new FieldCacheImpl.Entry(field, factory) : new FieldCacheImpl.Entry(field, type);
lock (Comparators.SyncRoot)
{
System.Collections.Hashtable readerCache = (System.Collections.Hashtable) Comparators[reader];
if (readerCache == null)
return null;
return (ScoreDocComparator) readerCache[entry];
}
}
/// <summary>Stores a comparator into the cache. </summary>
internal static System.Object Store(IndexReader reader, System.String field, int type, System.Object factory, System.Object value_Renamed)
{
FieldCacheImpl.Entry entry = (factory != null) ? new FieldCacheImpl.Entry(field, factory) : new FieldCacheImpl.Entry(field, type);
lock (Comparators.SyncRoot)
{
System.Collections.Hashtable readerCache = (System.Collections.Hashtable) Comparators[reader];
if (readerCache == null)
{
readerCache = new System.Collections.Hashtable();
Comparators[reader] = readerCache;
}
System.Object tempObject;
tempObject = readerCache[entry];
readerCache[entry] = value_Renamed;
return tempObject;
}
}
internal static ScoreDocComparator GetCachedComparator(IndexReader reader, System.String fieldname, int type, System.Globalization.CultureInfo locale, SortComparatorSource factory)
{
if (type == SortField.DOC)
return Lucene.Net.Search.ScoreDocComparator_Fields.INDEXORDER;
if (type == SortField.SCORE)
return Lucene.Net.Search.ScoreDocComparator_Fields.RELEVANCE;
ScoreDocComparator comparator = Lookup(reader, fieldname, type, factory);
if (comparator == null)
{
switch (type)
{
case SortField.AUTO:
comparator = ComparatorAuto(reader, fieldname);
break;
case SortField.INT:
comparator = ComparatorInt(reader, fieldname);
break;
case SortField.FLOAT:
comparator = ComparatorFloat(reader, fieldname);
break;
case SortField.STRING:
if (locale != null)
comparator = ComparatorStringLocale(reader, fieldname, locale);
else
comparator = ComparatorString(reader, fieldname);
break;
case SortField.CUSTOM:
comparator = factory.NewComparator(reader, fieldname);
break;
default:
throw new System.SystemException("unknown field type: " + type);
}
Store(reader, fieldname, type, factory, comparator);
}
return comparator;
}
/// <summary> Returns a comparator for sorting hits according to a field containing integers.</summary>
/// <param name="reader"> Index to use.
/// </param>
/// <param name="fieldname"> Field containg integer values.
/// </param>
/// <returns> Comparator for sorting hits.
/// </returns>
/// <throws> IOException If an error occurs reading the index. </throws>
internal static ScoreDocComparator ComparatorInt(IndexReader reader, System.String fieldname)
{
System.String field = String.Intern(fieldname);
int[] fieldOrder = Lucene.Net.Search.FieldCache_Fields.DEFAULT.GetInts(reader, field);
return new AnonymousClassScoreDocComparator(fieldOrder);
}
/// <summary> Returns a comparator for sorting hits according to a field containing floats.</summary>
/// <param name="reader"> Index to use.
/// </param>
/// <param name="fieldname"> Field containg float values.
/// </param>
/// <returns> Comparator for sorting hits.
/// </returns>
/// <throws> IOException If an error occurs reading the index. </throws>
internal static ScoreDocComparator ComparatorFloat(IndexReader reader, System.String fieldname)
{
System.String field = String.Intern(fieldname);
float[] fieldOrder = Lucene.Net.Search.FieldCache_Fields.DEFAULT.GetFloats(reader, field);
return new AnonymousClassScoreDocComparator1(fieldOrder);
}
/// <summary> Returns a comparator for sorting hits according to a field containing strings.</summary>
/// <param name="reader"> Index to use.
/// </param>
/// <param name="fieldname"> Field containg string values.
/// </param>
/// <returns> Comparator for sorting hits.
/// </returns>
/// <throws> IOException If an error occurs reading the index. </throws>
internal static ScoreDocComparator ComparatorString(IndexReader reader, System.String fieldname)
{
System.String field = String.Intern(fieldname);
Lucene.Net.Search.StringIndex index = Lucene.Net.Search.FieldCache_Fields.DEFAULT.GetStringIndex(reader, field);
return new AnonymousClassScoreDocComparator2(index);
}
/// <summary> Returns a comparator for sorting hits according to a field containing strings.</summary>
/// <param name="reader"> Index to use.
/// </param>
/// <param name="fieldname"> Field containg string values.
/// </param>
/// <returns> Comparator for sorting hits.
/// </returns>
/// <throws> IOException If an error occurs reading the index. </throws>
internal static ScoreDocComparator ComparatorStringLocale(IndexReader reader, System.String fieldname, System.Globalization.CultureInfo locale)
{
System.Globalization.CompareInfo collator = locale.CompareInfo;
System.String field = String.Intern(fieldname);
System.String[] index = Lucene.Net.Search.FieldCache_Fields.DEFAULT.GetStrings(reader, field);
return new AnonymousClassScoreDocComparator3(collator, index);
}
/// <summary> Returns a comparator for sorting hits according to values in the given field.
/// The terms in the field are looked at to determine whether they contain integers,
/// floats or strings. Once the type is determined, one of the other static methods
/// in this class is called to get the comparator.
/// </summary>
/// <param name="reader"> Index to use.
/// </param>
/// <param name="fieldname"> Field containg values.
/// </param>
/// <returns> Comparator for sorting hits.
/// </returns>
/// <throws> IOException If an error occurs reading the index. </throws>
internal static ScoreDocComparator ComparatorAuto(IndexReader reader, System.String fieldname)
{
System.String field = String.Intern(fieldname);
System.Object lookupArray = Lucene.Net.Search.FieldCache_Fields.DEFAULT.GetAuto(reader, field);
if (lookupArray is Lucene.Net.Search.StringIndex)
{
return ComparatorString(reader, field);
}
else if (lookupArray is int[])
{
return ComparatorInt(reader, field);
}
else if (lookupArray is float[])
{
return ComparatorFloat(reader, field);
}
else if (lookupArray is System.String[])
{
return ComparatorString(reader, field);
}
else
{
throw new System.SystemException("unknown data type in field '" + field + "'");
}
}
}
}
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