org.apache.lucene.search.grouping.function

Class FunctionAllGroupHeadsCollector

java.lang.Object

org.apache.lucene.search.Collector

org.apache.lucene.search.grouping.AbstractAllGroupHeadsCollector<FunctionAllGroupHeadsCollector.GroupHead>

org.apache.lucene.search.grouping.function.FunctionAllGroupHeadsCollector

public class FunctionAllGroupHeadsCollector
extends AbstractAllGroupHeadsCollector<FunctionAllGroupHeadsCollector.GroupHead>

An implementation of AbstractAllGroupHeadsCollector for retrieving the most relevant groups when grouping by ValueSource.

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
class	FunctionAllGroupHeadsCollector.GroupHead Holds current head document for a single group.

Nested classes/interfaces inherited from class org.apache.lucene.search.grouping.AbstractAllGroupHeadsCollector

AbstractAllGroupHeadsCollector.TemporalResult

Field Summary

Fields inherited from class org.apache.lucene.search.grouping.AbstractAllGroupHeadsCollector

compIDXEnd, reversed, temporalResult

Constructor Summary

Constructors

Constructor and Description
FunctionAllGroupHeadsCollector(ValueSource groupBy, Map<?,?> vsContext, Sort sortWithinGroup) Constructs a FunctionAllGroupHeadsCollector instance.

Method Summary

Methods

Modifier and Type	Method and Description
protected Collection<FunctionAllGroupHeadsCollector.GroupHead>	getCollectedGroupHeads() Returns the collected group heads.
protected void	retrieveGroupHeadAndAddIfNotExist(int doc) Returns the group head and puts it into AbstractAllGroupHeadsCollector.temporalResult.
void	setNextReader(AtomicReaderContext context) Called before collecting from each AtomicReaderContext.
void	setScorer(Scorer scorer) Called before successive calls to Collector.collect(int).

Methods inherited from class org.apache.lucene.search.grouping.AbstractAllGroupHeadsCollector

acceptsDocsOutOfOrder, collect, groupHeadsSize, retrieveGroupHeads, retrieveGroupHeads

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

FunctionAllGroupHeadsCollector

public FunctionAllGroupHeadsCollector(ValueSource groupBy,
                              Map<?,?> vsContext,
                              Sort sortWithinGroup)

Constructs a FunctionAllGroupHeadsCollector instance.

Parameters:

groupBy - The ValueSource to group by

vsContext - The ValueSource context

sortWithinGroup - The sort within a group

Method Detail

retrieveGroupHeadAndAddIfNotExist

protected void retrieveGroupHeadAndAddIfNotExist(int doc)
                                          throws IOException

Description copied from class: AbstractAllGroupHeadsCollector

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

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

Specified by:

retrieveGroupHeadAndAddIfNotExist in class AbstractAllGroupHeadsCollector<FunctionAllGroupHeadsCollector.GroupHead>

Parameters:

doc - The document to retrieve the group head for.

Throws:

IOException - If I/O related errors occur

getCollectedGroupHeads

protected Collection<FunctionAllGroupHeadsCollector.GroupHead> getCollectedGroupHeads()

Description copied from class: AbstractAllGroupHeadsCollector

Returns the collected group heads. Subsequent calls should return the same group heads.

Specified by:

getCollectedGroupHeads in class AbstractAllGroupHeadsCollector<FunctionAllGroupHeadsCollector.GroupHead>

Returns:

the collected group heads

setScorer

public void setScorer(Scorer scorer)
               throws IOException

Description copied from class: Collector

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

Specified by:

setScorer in class Collector

Throws:

IOException

setNextReader

public void setNextReader(AtomicReaderContext context)
                   throws IOException

Description copied from class: Collector

Called before collecting from each AtomicReaderContext. All doc ids in Collector.collect(int) will correspond to IndexReaderContext.reader(). Add AtomicReaderContext.docBase to the current IndexReaderContext.reader()'s internal document id to re-base ids in Collector.collect(int).

Specified by:

setNextReader in class Collector

Parameters:

context - next atomic reader context

Throws:

IOException