Class AbstractAllGroupHeadsCollector

LUCENENET specific class used to reference an AbstractAllGroupHeadsCollector<GH> subclass without refering to its generic closing type.

Inheritance

object

AbstractAllGroupHeadsCollector

AbstractAllGroupHeadsCollector<GH>

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.Search.Grouping

Assembly: Lucene.Net.Grouping.dll

Syntax

public abstract class AbstractAllGroupHeadsCollector : ICollector

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 abstract bool AcceptsDocsOutOfOrder { get; }

Property Value

Type	Description
bool

GroupHeadsCount

The number of group heads found for a query. LUCENENET NOTE: This was groupHeadsSize() in Lucene

Declaration

public abstract int GroupHeadsCount { get; }

Property Value

Type	Description
int	the number of group heads found for a query.

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 abstract void Collect(int doc)

Parameters

Type	Name	Description
int	doc

RetrieveGroupHeadAndAddIfNotExist(int)

Returns the group head and puts it into AbstractAllGroupHeadsCollector<GH>.TemporalResult. If the group head wasn't encountered before then it will be added to the collected group heads.

The Stop property will be true if the group head wasn't encountered before otherwise false.

Declaration

protected abstract void RetrieveGroupHeadAndAddIfNotExist(int doc)

Parameters

Type	Name	Description
int	doc	The document to retrieve the group head for.

Exceptions

Type	Condition
IOException	If I/O related errors occur

RetrieveGroupHeads()

LUCENENET specific class used to reference an AbstractAllGroupHeadsCollector<GH> subclass without refering to its generic closing type.

Declaration

public abstract int[] RetrieveGroupHeads()

Returns

Type	Description
int[]	an int array containing all group heads. The size of the array is equal to number of collected unique groups.

RetrieveGroupHeads(int)

LUCENENET specific class used to reference an AbstractAllGroupHeadsCollector<GH> subclass without refering to its generic closing type.

Declaration

public abstract FixedBitSet RetrieveGroupHeads(int maxDoc)

Parameters

Type	Name	Description
int	maxDoc	The maxDoc of the top level Lucene.Net.Index.IndexReader

Returns

Type	Description
FixedBitSet	a Lucene.Net.Util.FixedBitSet containing all group heads.

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 abstract 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 ), should save the passed-in Lucene.Net.Search.Scorer and call scorer.Score() when needed.

Declaration

public abstract void SetScorer(Scorer scorer)

Parameters

Type	Name	Description
Scorer	scorer

Implements

Lucene.Net.Search.ICollector