Package org.apache.lucene.codecs.bitvectors

Class HnswBitVectorsFormat

java.lang.Object

org.apache.lucene.codecs.KnnVectorsFormat

org.apache.lucene.codecs.bitvectors.HnswBitVectorsFormat

All Implemented Interfaces:

NamedSPILoader.NamedSPI

public final class HnswBitVectorsFormat
extends KnnVectorsFormat

Encodes bit vector values into an associated graph connecting the documents having values. The graph is used to power HNSW search. The format consists of two files, and uses Lucene99FlatVectorsFormat to store the actual vectors, but with a custom scorer implementation: For details on graph storage and file extensions, see Lucene99HnswVectorsFormat.

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

Field Summary

Fields

Modifier and Type	Field	Description
static final String	NAME

Fields inherited from class org.apache.lucene.codecs.KnnVectorsFormat

DEFAULT_MAX_DIMENSIONS, EMPTY

Constructor Summary

Constructors

Constructor	Description
HnswBitVectorsFormat()	Constructs a format using default graph construction parameters
HnswBitVectorsFormat(int maxConn, int beamWidth)	Constructs a format using the given graph construction parameters.
HnswBitVectorsFormat(int maxConn, int beamWidth, int numMergeWorkers, ExecutorService mergeExec)	Constructs a format using the given graph construction parameters and scalar quantization.

Method Summary

Modifier and Type	Method	Description
KnnVectorsReader	fieldsReader(SegmentReadState state)
KnnVectorsWriter	fieldsWriter(SegmentWriteState state)
int	getMaxDimensions(String fieldName)
String	toString()

Methods inherited from class org.apache.lucene.codecs.KnnVectorsFormat

availableKnnVectorsFormats, forName, getName, reloadKnnVectorsFormat

Methods inherited from class java.lang.Object

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

Field Details

NAME

public static final String NAME

See Also:

• Constant Field Values

Constructor Details

HnswBitVectorsFormat

public HnswBitVectorsFormat()

Constructs a format using default graph construction parameters

HnswBitVectorsFormat

public HnswBitVectorsFormat(int maxConn,
 int beamWidth)

Constructs a format using the given graph construction parameters.

Parameters:

maxConn - the maximum number of connections to a node in the HNSW graph

beamWidth - the size of the queue maintained during graph construction.

HnswBitVectorsFormat

public HnswBitVectorsFormat(int maxConn,
 int beamWidth,
 int numMergeWorkers,
 ExecutorService mergeExec)

Constructs a format using the given graph construction parameters and scalar quantization.

Parameters:

maxConn - the maximum number of connections to a node in the HNSW graph

beamWidth - the size of the queue maintained during graph construction.

numMergeWorkers - number of workers (threads) that will be used when doing merge. If larger than 1, a non-null ExecutorService must be passed as mergeExec

mergeExec - the ExecutorService that will be used by ALL vector writers that are generated by this format to do the merge

Method Details

fieldsWriter

public KnnVectorsWriter fieldsWriter(SegmentWriteState state)
                              throws IOException

Specified by:

fieldsWriter in class KnnVectorsFormat

Throws:

IOException

fieldsReader

public KnnVectorsReader fieldsReader(SegmentReadState state)
                              throws IOException

Specified by:

fieldsReader in class KnnVectorsFormat

Throws:

IOException

getMaxDimensions

public int getMaxDimensions(String fieldName)

Overrides:

getMaxDimensions in class KnnVectorsFormat

toString

public String toString()

Overrides:

toString in class Object