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.

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

Nested Class Summary

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

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

Method Summary

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)
void	setScorer(Scorer scorer)

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

Specified by:

setScorer in class Collector

Throws:

IOException

setNextReader

public void setNextReader(AtomicReaderContext context)
                   throws IOException

Specified by:

setNextReader in class Collector

Throws:

IOException