Class FacetsCollector

Collects hits for subsequent faceting. Once you've run a search and collect hits into this, instantiate one of the Lucene.Net.Search.ICollector subclasses to do the facet counting. Use the Search utility methods (such as Search(IndexSearcher, Query, int, ICollector)) to perform an "ordinary" search but also collect into a Facets.

Inheritance

object

FacetsCollector

RandomSamplingFacetsCollector

Implements

ICollector

Inherited Members

object.Equals(object)

object.Equals(object, object)

object.GetHashCode()

object.GetType()

object.MemberwiseClone()

object.ReferenceEquals(object, object)

object.ToString()

Namespace: Lucene.Net.Facet

Assembly: Lucene.Net.Facet.dll

Syntax

public class FacetsCollector : ICollector

Constructors

FacetsCollector()

Default constructor

Declaration

public FacetsCollector()

FacetsCollector(bool)

Create this; if keepScores is true then a float[] is allocated to hold score of all hits.

Declaration

public FacetsCollector(bool keepScores)

Parameters

Type	Name	Description
bool	keepScores

Properties

AcceptsDocsOutOfOrder

Return true if this collector does not require the matching docIDs to be delivered in int sort order (smallest to largest) to Collect(int).

Most Lucene Query implementations will visit matching docIDs in order. However, some queries (currently limited to certain cases of Lucene.Net.Search.BooleanQuery) can achieve faster searching if the Lucene.Net.Search.ICollector allows them to deliver the docIDs out of order.

Many collectors don't mind getting docIDs out of order, so it's important to return true here.

Declaration

public bool AcceptsDocsOutOfOrder { get; }

Property Value

Type	Description
bool

KeepScores

True if scores were saved.

Declaration

public bool KeepScores { get; }

Property Value

Type	Description
bool

Methods

Collect(int)

Called once for every document matching a query, with the unbased document number.

Note: The collection of the current segment can be terminated by throwing a Lucene.Net.Search.CollectionTerminatedException. In this case, the last docs of the current Lucene.Net.Index.AtomicReaderContext will be skipped and Lucene.Net.Search.IndexSearcher will swallow the exception and continue collection with the next leaf.

Note: this is called in an inner search loop. For good search performance, implementations of this method should not call Doc(int) or Document(int) on every hit. Doing so can slow searches by an order of magnitude or more.

Declaration

public void Collect(int doc)

Parameters

Type	Name	Description
int	doc

CreateDocs(int)

Creates a FacetsCollector.Docs to record hits. The default uses Lucene.Net.Util.FixedBitSet to record hits and you can override to e.g. record the docs in your own Lucene.Net.Search.DocIdSet.

Declaration

protected virtual FacetsCollector.Docs CreateDocs(int maxDoc)

Parameters

Type	Name	Description
int	maxDoc

Returns

Type	Description
FacetsCollector.Docs

GetMatchingDocs()

Returns the documents matched by the query, one FacetsCollector.MatchingDocs per visited segment.

Declaration

public virtual IList<FacetsCollector.MatchingDocs> GetMatchingDocs()

Returns

Type	Description
IList<FacetsCollector.MatchingDocs>

Search(IndexSearcher, Query, Filter, int, ICollector)

Utility method, to search and also collect all hits into the provided Lucene.Net.Search.ICollector.

Declaration

public static TopDocs Search(IndexSearcher searcher, Query q, Filter filter, int n, ICollector fc)

Parameters

Type	Name	Description
IndexSearcher	searcher
Query	q
Filter	filter
int	n
ICollector	fc

Returns

Type	Description
TopDocs

Search(IndexSearcher, Query, Filter, int, Sort, ICollector)

Utility method, to search and also collect all hits into the provided Lucene.Net.Search.ICollector.

Declaration

public static TopFieldDocs Search(IndexSearcher searcher, Query q, Filter filter, int n, Sort sort, ICollector fc)

Parameters

Type	Name	Description
IndexSearcher	searcher
Query	q
Filter	filter
int	n
Sort	sort
ICollector	fc

Returns

Type	Description
TopFieldDocs

Search(IndexSearcher, Query, Filter, int, Sort, bool, bool, ICollector)

Utility method, to search and also collect all hits into the provided Lucene.Net.Search.ICollector.

Declaration

public static TopFieldDocs Search(IndexSearcher searcher, Query q, Filter filter, int n, Sort sort, bool doDocScores, bool doMaxScore, ICollector fc)

Parameters

Type	Name	Description
IndexSearcher	searcher
Query	q
Filter	filter
int	n
Sort	sort
bool	doDocScores
bool	doMaxScore
ICollector	fc

Returns

Type	Description
TopFieldDocs

Search(IndexSearcher, Query, int, ICollector)

Utility method, to search and also collect all hits into the provided Lucene.Net.Search.ICollector.

Declaration

public static TopDocs Search(IndexSearcher searcher, Query q, int n, ICollector fc)

Parameters

Type	Name	Description
IndexSearcher	searcher
Query	q
int	n
ICollector	fc

Returns

Type	Description
TopDocs

SearchAfter(IndexSearcher, ScoreDoc, Query, Filter, int, ICollector)

Utility method, to search and also collect all hits into the provided Lucene.Net.Search.ICollector.

Declaration

public static TopDocs SearchAfter(IndexSearcher searcher, ScoreDoc after, Query q, Filter filter, int n, ICollector fc)

Parameters

Type	Name	Description
IndexSearcher	searcher
ScoreDoc	after
Query	q
Filter	filter
int	n
ICollector	fc

Returns

Type	Description
TopDocs

SearchAfter(IndexSearcher, ScoreDoc, Query, Filter, int, Sort, ICollector)

Utility method, to search and also collect all hits into the provided Lucene.Net.Search.ICollector.

Declaration

public static TopDocs SearchAfter(IndexSearcher searcher, ScoreDoc after, Query q, Filter filter, int n, Sort sort, ICollector fc)

Parameters

Type	Name	Description
IndexSearcher	searcher
ScoreDoc	after
Query	q
Filter	filter
int	n
Sort	sort
ICollector	fc

Returns

Type	Description
TopDocs

SearchAfter(IndexSearcher, ScoreDoc, Query, Filter, int, Sort, bool, bool, ICollector)

Utility method, to search and also collect all hits into the provided Lucene.Net.Search.ICollector.

Declaration

public static TopDocs SearchAfter(IndexSearcher searcher, ScoreDoc after, Query q, Filter filter, int n, Sort sort, bool doDocScores, bool doMaxScore, ICollector fc)

Parameters

Type	Name	Description
IndexSearcher	searcher
ScoreDoc	after
Query	q
Filter	filter
int	n
Sort	sort
bool	doDocScores
bool	doMaxScore
ICollector	fc

Returns

Type	Description
TopDocs

SearchAfter(IndexSearcher, ScoreDoc, Query, int, ICollector)

Utility method, to search and also collect all hits into the provided Lucene.Net.Search.ICollector.

Declaration

public virtual TopDocs SearchAfter(IndexSearcher searcher, ScoreDoc after, Query q, int n, ICollector fc)

Parameters

Type	Name	Description
IndexSearcher	searcher
ScoreDoc	after
Query	q
int	n
ICollector	fc

Returns

Type	Description
TopDocs

SetNextReader(AtomicReaderContext)

Called before collecting from each Lucene.Net.Index.AtomicReaderContext. All doc ids in Collect(int) will correspond to Lucene.Net.Index.IndexReaderContext.Reader.

Add Lucene.Net.Index.AtomicReaderContext.DocBase to the current Lucene.Net.Index.IndexReaderContext.Reader's internal document id to re-base ids in Collect(int).

Declaration

public void SetNextReader(AtomicReaderContext context)

Parameters

Type	Name	Description
AtomicReaderContext	context	next atomic reader context

SetScorer(Scorer)

Called before successive calls to Collect(int). Implementations that need the score of the current document (passed-in to Collect(int)), should save the passed-in Lucene.Net.Search.Scorer and call scorer.GetScore() when needed.

Declaration

public void SetScorer(Scorer scorer)

Parameters

Type	Name	Description
Scorer	scorer

Implements

Lucene.Net.Search.ICollector