IncrementalHnswGraphMerger (Lucene 10.5.0 core API)
Description: declaration: package: org.apache.lucene.util.hnsw, class: IncrementalHnswGraphMerger

Package org.apache.lucene.util.hnsw

# Class IncrementalHnswGraphMerger

java.lang.Object
org.apache.lucene.util.hnsw.IncrementalHnswGraphMerger

All Implemented Interfaces:
  `HnswGraphMerger`

Direct Known Subclasses:
  `ConcurrentHnswMerger`

public class IncrementalHnswGraphMerger extends Object implements HnswGraphMerger
This merges multiple graphs in a single thread in incremental fashion.

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
  `protected static final record`
  `IncrementalHnswGraphMerger.GraphReader`
  Represents a vector reader that contains graph info.

- ## Field Summary

  Fields
  Modifier and Type
  Field
  Description
  `protected final int`
  `beamWidth`
  `protected final FieldInfo`
  `fieldInfo`
  `protected List<IncrementalHnswGraphMerger.GraphReader>`
  `graphReaders`
  `protected IncrementalHnswGraphMerger.GraphReader`
  `largestGraphReader`
  `protected final int`
  `M`
  `protected final RandomVectorScorerSupplier`
  `scorerSupplier`

- ## Constructor Summary

  Constructors
  Constructor
  Description
  `IncrementalHnswGraphMerger(FieldInfo fieldInfo, RandomVectorScorerSupplier scorerSupplier, int M, int beamWidth)`

- ## Method Summary

  Modifier and Type
  Method
  Description
  `IncrementalHnswGraphMerger`
  `addReader(KnnVectorsReader reader, MergeState.DocMap docMap, Bits liveDocs)`
  Adds a reader to the graph merger if it meets the following criteria: 1.
  `protected HnswBuilder`
  `createBuilder(KnnVectorValues mergedVectorValues, int maxOrd)`
  Builds a new HnswGraphBuilder
  `protected final int[][]`
  `getNewOrdMapping(KnnVectorValues mergedVectorValues, BitSet initializedNodes)`
  `OnHeapHnswGraph`
  `merge(KnnVectorValues mergedVectorValues, InfoStream infoStream, int maxOrd)`
  Merge and produce the on heap graph

  ### Methods inherited from class java.lang.Object

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

- ## Field Details

  - ### fieldInfo

    protected final FieldInfo fieldInfo

  - ### scorerSupplier

    protected final RandomVectorScorerSupplier scorerSupplier

  - ### M

    protected final int M

  - ### beamWidth

    protected final int beamWidth

  - ### graphReaders

    protected List<IncrementalHnswGraphMerger.GraphReader> graphReaders

  - ### largestGraphReader

    protected IncrementalHnswGraphMerger.GraphReader largestGraphReader

- ## Constructor Details

  - ### IncrementalHnswGraphMerger

    public IncrementalHnswGraphMerger(FieldInfo fieldInfo, RandomVectorScorerSupplier scorerSupplier, int M, int beamWidth)
    Parameters:
      `fieldInfo` - FieldInfo for the field being merged

- ## Method Details

  - ### addReader

    public IncrementalHnswGraphMerger addReader(KnnVectorsReader reader, MergeState.DocMap docMap, Bits liveDocs) throws IOException
    Adds a reader to the graph merger if it meets the following criteria: 1. does not contain any deleted vector 2. is a HnswGraphProvider
    Specified by:
      `addReader` in interface `HnswGraphMerger`
    Parameters:
      `reader` - KnnVectorsReader to add to the merger
      `docMap` - MergeState.DocMap for the reader
      `liveDocs` - Bits representing live docs, can be null
    Returns:
      this
    Throws:
      `IOException` - If an error occurs while reading from the merge state

  - ### createBuilder

    protected HnswBuilder createBuilder(KnnVectorValues mergedVectorValues, int maxOrd) throws IOException
    Builds a new HnswGraphBuilder
    Parameters:
      `mergedVectorValues` - vector values in the merged segment
      `maxOrd` - max num of vectors that will be merged into the graph
    Returns:
      HnswGraphBuilder
    Throws:
      `IOException` - If an error occurs while reading from the merge state

  - ### getNewOrdMapping

    protected final int[][] getNewOrdMapping(KnnVectorValues mergedVectorValues, BitSet initializedNodes) throws IOException
    Throws:
      `IOException`

  - ### merge

    public OnHeapHnswGraph merge(KnnVectorValues mergedVectorValues, InfoStream infoStream, int maxOrd) throws IOException
    Description copied from interface: `HnswGraphMerger`
    Merge and produce the on heap graph
    Specified by:
      `merge` in interface `HnswGraphMerger`
    Parameters:
      `mergedVectorValues` - view of the vectors in the merged segment
      `infoStream` - optional info stream to set to builder
      `maxOrd` - max number of vectors that will be added to the graph
    Returns:
      merged graph
    Throws:
      `IOException` - during merge