org.apache.lucene.search.grouping

Class AbstractGroupFacetCollector

java.lang.Object

org.apache.lucene.search.SimpleCollector

org.apache.lucene.search.grouping.AbstractGroupFacetCollector

All Implemented Interfaces:

Collector, LeafCollector

Direct Known Subclasses:

TermGroupFacetCollector

public abstract class AbstractGroupFacetCollector
extends SimpleCollector

Base class for computing grouped facets.

Nested Class Summary

Nested Classes

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

Field Summary

Fields

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

Constructor Summary

Constructors

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

Method Summary

Modifier and Type	Method and Description
protected abstract AbstractGroupFacetCollector.SegmentResult	createSegmentResult()
AbstractGroupFacetCollector.GroupedFacetResult	mergeSegmentResults(int size, int minCount, boolean orderByCount) Returns grouped facet results that were computed over zero or more segments.
void	setScorer(Scorer scorer) Called before successive calls to LeafCollector.collect(int).

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.Collector

needsScores

Field Detail

groupField

protected final String groupField

facetField

protected final String facetField

facetPrefix

protected final BytesRef facetPrefix

segmentResults

protected final List<AbstractGroupFacetCollector.SegmentResult> segmentResults

segmentFacetCounts

protected int[] segmentFacetCounts

segmentTotalCount

protected int segmentTotalCount

startFacetOrd

protected int startFacetOrd

endFacetOrd

protected int endFacetOrd

Constructor Detail

AbstractGroupFacetCollector

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

Method Detail

mergeSegmentResults

public AbstractGroupFacetCollector.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 AbstractGroupFacetCollector.SegmentResult createSegmentResult()
                                                                          throws IOException

Throws:

IOException

setScorer

public void setScorer(Scorer scorer)
               throws IOException

Description copied from interface: LeafCollector

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

Specified by:

setScorer in interface LeafCollector

Overrides:

setScorer in class SimpleCollector

Throws:

IOException