Package org.apache.lucene.search.grouping

Class GroupFacetCollector

java.lang.Object

org.apache.lucene.search.SimpleCollector

org.apache.lucene.search.grouping.GroupFacetCollector

All Implemented Interfaces:

Collector, LeafCollector

Direct Known Subclasses:

TermGroupFacetCollector

public abstract class GroupFacetCollector
extends SimpleCollector

Base class for computing grouped facets.

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

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static class	GroupFacetCollector.FacetEntry	Represents a facet entry with a value and a count.
static class	GroupFacetCollector.GroupedFacetResult	The grouped facet result.
protected static class	GroupFacetCollector.SegmentResult	Contains the local grouped segment counts for a particular segment.

Field Summary

Fields

Modifier and Type	Field	Description
protected int	endFacetOrd
protected final String	facetField
protected final BytesRef	facetPrefix
protected final String	groupField
protected int[]	segmentFacetCounts
protected final List<GroupFacetCollector.SegmentResult>	segmentResults
protected int	segmentTotalCount
protected int	startFacetOrd

Constructor Summary

Constructors

Modifier	Constructor	Description
protected	GroupFacetCollector(String groupField, String facetField, BytesRef facetPrefix)

Method Summary

Modifier and Type	Method	Description
protected abstract GroupFacetCollector.SegmentResult	createSegmentResult()
GroupFacetCollector.GroupedFacetResult	mergeSegmentResults(int size, int minCount, boolean orderByCount)	Returns grouped facet results that were computed over zero or more segments.
ScoreMode	scoreMode()
void	setScorer(Scorable scorer)

Methods inherited from class org.apache.lucene.search.SimpleCollector

collect, doSetNextReader, getLeafCollector

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.apache.lucene.search.LeafCollector

competitiveIterator

Field Details

groupField

protected final String groupField

facetField

protected final String facetField

facetPrefix

protected final BytesRef facetPrefix

segmentResults

protected final List<GroupFacetCollector.SegmentResult> segmentResults

segmentFacetCounts

protected int[] segmentFacetCounts

segmentTotalCount

protected int segmentTotalCount

startFacetOrd

protected int startFacetOrd

endFacetOrd

protected int endFacetOrd

Constructor Details

GroupFacetCollector

protected GroupFacetCollector(String groupField,
 String facetField,
 BytesRef facetPrefix)

Method Details

mergeSegmentResults

public GroupFacetCollector.GroupedFacetResult mergeSegmentResults(int size,
 int minCount,
 boolean orderByCount)
                                                           throws IOException

Returns grouped facet results that were computed over zero or more segments. Grouped facet counts are merged from zero or more segment results.

Parameters:

size - The total number of facets to include. This is typically offset + limit

minCount - The minimum count a facet entry should have to be included in the grouped facet result

orderByCount - Whether to sort the facet entries by facet entry count. If false then the facets are sorted lexicographically in ascending order.

Returns:

grouped facet results

Throws:

IOException - If I/O related errors occur during merging segment grouped facet counts.

createSegmentResult

protected abstract GroupFacetCollector.SegmentResult createSegmentResult()
                                                                  throws IOException

Throws:

IOException

setScorer

public void setScorer(Scorable scorer)
               throws IOException

Specified by:

setScorer in interface LeafCollector

Overrides:

setScorer in class SimpleCollector

Throws:

IOException

scoreMode

public ScoreMode scoreMode()