Package org.apache.lucene.util.hnsw

Class NeighborArray

java.lang.Object

org.apache.lucene.util.hnsw.NeighborArray

public class NeighborArray
extends Object

NeighborArray encodes the neighbors of a node and their mutual scores in the HNSW graph as a pair of growable arrays. Nodes are arranged in the sorted order of their scores in descending order (if scoresDescOrder is true), or in the ascending order of their scores (if scoresDescOrder is false)

NOTE: This API is for internal purposes only and might change in incompatible ways in the next release.

Field Summary

Fields

Modifier and Type	Field	Description
ReadWriteLock	rwlock

Constructor Summary

Constructors

Constructor	Description
NeighborArray(int maxSize, boolean descOrder)

Method Summary

Modifier and Type	Method	Description
void	addAndEnsureDiversity(int newNode, float newScore, int nodeId, RandomVectorScorerSupplier scorerSupplier)	In addition to addOutOfOrder(int, float), this function will also remove the least-diverse node if the node array is full after insertion
void	addInOrder(int newNode, float newScore)	Add a new node to the NeighborArray.
void	addOutOfOrder(int newNode, float newScore)	Add node and newScore but do not insert as sorted
void	clear()
int[]	nodes()	Direct access to the internal list of node ids; provided for efficient writing of the graph
float[]	scores()
int	size()
String	toString()

Methods inherited from class java.lang.Object

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

Field Detail

rwlock

public final ReadWriteLock rwlock

Constructor Detail

NeighborArray

public NeighborArray(int maxSize,
                     boolean descOrder)

Method Detail

addInOrder

public void addInOrder(int newNode,
                       float newScore)

Add a new node to the NeighborArray. The new node must be worse than all previously stored nodes. This cannot be called after addOutOfOrder(int, float)

addOutOfOrder

public void addOutOfOrder(int newNode,
                          float newScore)

Add node and newScore but do not insert as sorted

addAndEnsureDiversity

public void addAndEnsureDiversity(int newNode,
                                  float newScore,
                                  int nodeId,
                                  RandomVectorScorerSupplier scorerSupplier)
                           throws IOException

In addition to addOutOfOrder(int, float), this function will also remove the least-diverse node if the node array is full after insertion

In multi-threading environment, this method need to be locked as it will be called by multiple threads while other add method is only supposed to be called by one thread.

Parameters:

nodeId - node Id of the owner of this NeighbourArray

Throws:

IOException

size

public int size()

nodes

public int[] nodes()

Direct access to the internal list of node ids; provided for efficient writing of the graph

NOTE: This API is for internal purposes only and might change in incompatible ways in the next release.

scores

public float[] scores()

clear

public void clear()

toString

public String toString()

Overrides:

toString in class Object