Package org.apache.lucene.search.knn

Class MultiLeafKnnCollector

java.lang.Object

org.apache.lucene.search.KnnCollector.Decorator

org.apache.lucene.search.knn.MultiLeafKnnCollector

All Implemented Interfaces:

KnnCollector

public final class MultiLeafKnnCollector
extends KnnCollector.Decorator

MultiLeafKnnCollector is a specific KnnCollector that can exchange the top collected results across segments through a shared global queue.

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

Nested Class Summary

Nested classes/interfaces inherited from interface org.apache.lucene.search.KnnCollector

KnnCollector.Decorator

Field Summary

Fields inherited from class org.apache.lucene.search.KnnCollector.Decorator

collector

Constructor Summary

Constructors

Constructor	Description
MultiLeafKnnCollector(int k, float greediness, int interval, BlockingFloatHeap globalSimilarityQueue, AbstractKnnCollector subCollector)	Create a new MultiLeafKnnCollector.
MultiLeafKnnCollector(int k, BlockingFloatHeap globalSimilarityQueue, AbstractKnnCollector subCollector)	Create a new MultiLeafKnnCollector.

Method Summary

Modifier and Type	Method	Description
boolean	collect(int docId, float similarity)	Collect the provided docId and include in the result set.
float	minCompetitiveSimilarity()	This method is utilized during search to ensure only competitive results are explored.
String	toString()

Methods inherited from class org.apache.lucene.search.KnnCollector.Decorator

earlyTerminated, getSearchStrategy, incVisitedCount, k, topDocs, visitedCount, visitLimit

Methods inherited from class java.lang.Object

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

Constructor Details

MultiLeafKnnCollector

public MultiLeafKnnCollector(int k,
 BlockingFloatHeap globalSimilarityQueue,
 AbstractKnnCollector subCollector)

Create a new MultiLeafKnnCollector.

Parameters:

k - the number of neighbors to collect

globalSimilarityQueue - the global queue of the highest similarities collected so far across all segments

subCollector - the local collector

MultiLeafKnnCollector

public MultiLeafKnnCollector(int k,
 float greediness,
 int interval,
 BlockingFloatHeap globalSimilarityQueue,
 AbstractKnnCollector subCollector)

Create a new MultiLeafKnnCollector.

Parameters:

k - the number of neighbors to collect

greediness - the greediness of the global search

interval - (by number of collected values) the interval to synchronize the local and global queues

globalSimilarityQueue - the global queue of the highest similarities collected so far

subCollector - the local collector

Method Details

collect

public boolean collect(int docId,
 float similarity)

Description copied from interface: KnnCollector

Collect the provided docId and include in the result set.

Specified by:

collect in interface KnnCollector

Overrides:

collect in class KnnCollector.Decorator

Parameters:

docId - of the vector to collect

similarity - its calculated similarity

Returns:

true if the vector is collected

minCompetitiveSimilarity

public float minCompetitiveSimilarity()

Description copied from interface: KnnCollector

This method is utilized during search to ensure only competitive results are explored.

Consequently, if this results collector wants to collect `k` results, this should return Float.NEGATIVE_INFINITY when not full.

When full, the minimum score should be returned.

Specified by:

minCompetitiveSimilarity in interface KnnCollector

Overrides:

minCompetitiveSimilarity in class KnnCollector.Decorator

Returns:

the current minimum competitive similarity in the collection

toString

public String toString()

Overrides:

toString in class Object