Package org.apache.lucene.codecs.perfield

Class PerFieldKnnVectorsFormat

java.lang.Object

org.apache.lucene.codecs.KnnVectorsFormat

org.apache.lucene.codecs.perfield.PerFieldKnnVectorsFormat

All Implemented Interfaces:

NamedSPILoader.NamedSPI

public abstract class PerFieldKnnVectorsFormat
extends KnnVectorsFormat

Enables per field numeric vector support.

Note, when extending this class, the name (KnnVectorsFormat.getName()) is written into the index. In order for the field to be read, the name must resolve to your implementation via KnnVectorsFormat.forName(String). This method uses Java's Service Provider Interface to resolve format names.

Files written by each numeric vectors format have an additional suffix containing the format name. For example, in a per-field configuration instead of _1.dat filenames would look like _1_Lucene40_0.dat.

See Also:

• ServiceLoader

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

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static class	PerFieldKnnVectorsFormat.FieldsReader	VectorReader that can wrap multiple delegate readers, selected by field.

Field Summary

Fields

Modifier and Type	Field	Description
static final String	PER_FIELD_FORMAT_KEY	FieldInfo attribute name used to store the format name for each field.
static final String	PER_FIELD_NAME	Name of this KnnVectorsFormat.
static final String	PER_FIELD_SUFFIX_KEY	FieldInfo attribute name used to store the segment suffix name for each field.

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

EMPTY

Constructor Summary

Constructors

Modifier	Constructor	Description
protected	PerFieldKnnVectorsFormat()	Sole constructor.

Method Summary

Modifier and Type	Method	Description
KnnVectorsReader	fieldsReader(SegmentReadState state)	Returns a KnnVectorsReader to read the vectors from the index.
KnnVectorsWriter	fieldsWriter(SegmentWriteState state)	Returns a KnnVectorsWriter to write the vectors to the index.
abstract KnnVectorsFormat	getKnnVectorsFormatForField(String field)	Returns the numeric vector format that should be used for writing new segments of field .

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

forName, getName

Methods inherited from class java.lang.Object

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

Field Details

PER_FIELD_NAME

public static final String PER_FIELD_NAME

Name of this KnnVectorsFormat.

See Also:

• Constant Field Values

PER_FIELD_FORMAT_KEY

public static final String PER_FIELD_FORMAT_KEY

FieldInfo attribute name used to store the format name for each field.

PER_FIELD_SUFFIX_KEY

public static final String PER_FIELD_SUFFIX_KEY

FieldInfo attribute name used to store the segment suffix name for each field.

Constructor Details

PerFieldKnnVectorsFormat

protected PerFieldKnnVectorsFormat()

Sole constructor.

Method Details

fieldsWriter

public KnnVectorsWriter fieldsWriter(SegmentWriteState state)
                              throws IOException

Description copied from class: KnnVectorsFormat

Returns a KnnVectorsWriter to write the vectors to the index.

Specified by:

fieldsWriter in class KnnVectorsFormat

Throws:

IOException

fieldsReader

public KnnVectorsReader fieldsReader(SegmentReadState state)
                              throws IOException

Description copied from class: KnnVectorsFormat

Returns a KnnVectorsReader to read the vectors from the index.

Specified by:

fieldsReader in class KnnVectorsFormat

Throws:

IOException

getKnnVectorsFormatForField

public abstract KnnVectorsFormat getKnnVectorsFormatForField(String field)

Returns the numeric vector format that should be used for writing new segments of field .

The field to format mapping is written to the index, so this method is only invoked when writing, not when reading.