Class AbstractSecondPassGroupingCollector<TGroupValue>

SecondPassGroupingCollector is the second of two passes necessary to collect grouped docs. This pass gathers the top N documents per top group computed from the first pass. Concrete subclasses define what a group is and how it is internally collected.

See org.apache.lucene.search.grouping for more details including a full code example.

Note

This API is experimental and might change in incompatible ways in the next release.

Inheritance

object

AbstractSecondPassGroupingCollector<TGroupValue>

FunctionSecondPassGroupingCollector<TMutableValue>

TermSecondPassGroupingCollector

Implements

IAbstractSecondPassGroupingCollector<TGroupValue>

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 AbstractSecondPassGroupingCollector<TGroupValue> : IAbstractSecondPassGroupingCollector<TGroupValue>, ICollector

Type Parameters

Name	Description
TGroupValue

Constructors

AbstractSecondPassGroupingCollector(IEnumerable<ISearchGroup<TGroupValue>>, Sort, Sort, int, bool, bool, bool)

SecondPassGroupingCollector is the second of two passes necessary to collect grouped docs. This pass gathers the top N documents per top group computed from the first pass. Concrete subclasses define what a group is and how it is internally collected.

See org.apache.lucene.search.grouping for more details including a full code example.

Note

This API is experimental and might change in incompatible ways in the next release.

Declaration

protected AbstractSecondPassGroupingCollector(IEnumerable<ISearchGroup<TGroupValue>> groups, Sort groupSort, Sort withinGroupSort, int maxDocsPerGroup, bool getScores, bool getMaxScores, bool fillSortFields)

Parameters

Type	Name	Description
IEnumerable<ISearchGroup<TGroupValue>>	groups
Sort	groupSort
Sort	withinGroupSort
int	maxDocsPerGroup
bool	getScores
bool	getMaxScores
bool	fillSortFields

Fields

m_groupDocs

SecondPassGroupingCollector is the second of two passes necessary to collect grouped docs. This pass gathers the top N documents per top group computed from the first pass. Concrete subclasses define what a group is and how it is internally collected.

See org.apache.lucene.search.grouping for more details including a full code example.

Note

This API is experimental and might change in incompatible ways in the next release.

Declaration

protected AbstractSecondPassGroupingCollector.SearchGroupDocs<TGroupValue>[] m_groupDocs

Field Value

Type	Description
SearchGroupDocs<TGroupValue>[]

m_groupMap

SecondPassGroupingCollector is the second of two passes necessary to collect grouped docs. This pass gathers the top N documents per top group computed from the first pass. Concrete subclasses define what a group is and how it is internally collected.

See org.apache.lucene.search.grouping for more details including a full code example.

Note

This API is experimental and might change in incompatible ways in the next release.

Declaration

protected readonly IDictionary<TGroupValue, AbstractSecondPassGroupingCollector.SearchGroupDocs<TGroupValue>> m_groupMap

Field Value

Type	Description
IDictionary<TGroupValue, AbstractSecondPassGroupingCollector.SearchGroupDocs<TGroupValue>>

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 virtual bool AcceptsDocsOutOfOrder { 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 virtual void Collect(int doc)

Parameters

Type	Name	Description
int	doc

GetTopGroups(int)

SecondPassGroupingCollector is the second of two passes necessary to collect grouped docs. This pass gathers the top N documents per top group computed from the first pass. Concrete subclasses define what a group is and how it is internally collected.

See org.apache.lucene.search.grouping for more details including a full code example.

Note

This API is experimental and might change in incompatible ways in the next release.

Declaration

public virtual ITopGroups<TGroupValue> GetTopGroups(int withinGroupOffset)

Parameters

Type	Name	Description
int	withinGroupOffset

Returns

Type	Description
ITopGroups<TGroupValue>

RetrieveGroup(int)

Returns the group the specified doc belongs to or null if no group could be retrieved.

Declaration

protected abstract AbstractSecondPassGroupingCollector.SearchGroupDocs<TGroupValue> RetrieveGroup(int doc)

Parameters

Type	Name	Description
int	doc	The specified doc

Returns

Type	Description
AbstractSecondPassGroupingCollector.SearchGroupDocs<TGroupValue>	the group the specified doc belongs to or null if no group could be retrieved

Exceptions

Type	Condition
IOException	If an I/O related error occurred

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 virtual 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 virtual void SetScorer(Scorer scorer)

Parameters

Type	Name	Description
Scorer	scorer

Implements

IAbstractSecondPassGroupingCollector<TGroupValue>

Lucene.Net.Search.ICollector