Package org.apache.lucene.misc.search

Class DiversifiedTopDocsCollectorManager<C extends DiversifiedTopDocsCollector>

java.lang.Object

org.apache.lucene.misc.search.DiversifiedTopDocsCollectorManager<C>

All Implemented Interfaces:

CollectorManager<C,TopDocs>

public abstract class DiversifiedTopDocsCollectorManager<C extends DiversifiedTopDocsCollector>
extends Object
implements CollectorManager<C,TopDocs>

A CollectorManager for DiversifiedTopDocsCollector. Subclasses implement CollectorManager.newCollector() to supply concrete collector instances; this class provides the reduce(Collection) that merges per-slice results while preserving the diversity constraint across the whole result set.

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

Constructor Summary

Constructors

Modifier	Constructor	Description
protected	DiversifiedTopDocsCollectorManager(int numHits, int maxHitsPerKey)

Method Summary

Modifier and Type	Method	Description
TopDocs	reduce(Collection<C> collectors)	Merges per-slice results into a single TopDocs while re-applying the diversity constraint globally.

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.CollectorManager

newCollector

Constructor Details

DiversifiedTopDocsCollectorManager

protected DiversifiedTopDocsCollectorManager(int numHits,
 int maxHitsPerKey)

Parameters:

numHits - maximum number of results to return

maxHitsPerKey - maximum number of results per key allowed in the final results

Method Details

reduce

public TopDocs reduce(Collection<C> collectors)
               throws IOException

Merges per-slice results into a single TopDocs while re-applying the diversity constraint globally. Each per-slice collector may contain up to numHits results, but the same key can appear in multiple slices; reduce enforces maxHitsPerKey across all slices.

Specified by:

reduce in interface CollectorManager<C extends DiversifiedTopDocsCollector,TopDocs>

Throws:

IOException