Class HnswGraphBuilder

  • public final class HnswGraphBuilder
    extends Object
    Builder for HNSW graph. See HnswGraph for a gloss on the algorithm and the meaning of the hyperparameters.
    • Field Detail


        public static final String HNSW_COMPONENT
        A name for the HNSW component for the info-stream *
        See Also:
        Constant Field Values
      • randSeed

        public static long randSeed
        Random seed for level generation; public to expose for testing *
    • Constructor Detail

      • HnswGraphBuilder

        public HnswGraphBuilder​(RandomAccessVectorValuesProducer vectors,
                                VectorSimilarityFunction similarityFunction,
                                int M,
                                int beamWidth,
                                long seed)
                         throws IOException
        Reads all the vectors from a VectorValues, builds a graph connecting them by their dense ordinals, using the given hyperparameter settings, and returns the resulting graph.
        vectors - the vectors whose relations are represented by the graph - must provide a different view over those vectors than the one used to add via addGraphNode.
        M - – graph fanout parameter used to calculate the maximum number of connections a node can have – M on upper layers, and M * 2 on the lowest level.
        beamWidth - the size of the beam search to use when finding nearest neighbors.
        seed - the seed for a random number generator used during graph construction. Provide this to ensure repeatable construction.
    • Method Detail

      • build

        public OnHeapHnswGraph build​(RandomAccessVectorValues vectors)
                              throws IOException
        Reads all the vectors from two copies of a random access VectorValues. Providing two copies enables efficient retrieval without extra data copying, while avoiding collision of the returned values.
        vectors - the vectors for which to build a nearest neighbors graph. Must be an independet accessor for the vectors
      • setInfoStream

        public void setInfoStream​(InfoStream infoStream)
        Set info-stream to output debugging information *