Package org.apache.lucene.util.hnsw

Class HnswGraphBuilder.GraphBuilderKnnCollector

java.lang.Object
org.apache.lucene.util.hnsw.HnswGraphBuilder.GraphBuilderKnnCollector
All Implemented Interfaces:
KnnCollector
Enclosing class:
HnswGraphBuilder
public static final class HnswGraphBuilder.GraphBuilderKnnCollector extends Object implements KnnCollector
A restricted, specialized knnCollector that can be used when building a graph.

Does not support TopDocs

  • Constructor Details

    • GraphBuilderKnnCollector

      public GraphBuilderKnnCollector(int k)
      Parameters:
      k - the number of neighbors to collect

  • Method Details

    • size

      public int size()

    • popNode

      public int popNode()

    • popUntilNearestKNodes

      public int[] popUntilNearestKNodes()

    • clear

      public void clear()

    • earlyTerminated

      public boolean earlyTerminated()
      Description copied from interface: KnnCollector
      If search visits too many documents, the results collector will terminate early. Usually, this is due to some restricted filter on the document set.

      When collection is earlyTerminated, the results are not a correct representation of k nearest neighbors.

      Specified by:
      earlyTerminated in interface KnnCollector
      Returns:
      is the current result set marked as incomplete?

    • incVisitedCount

      public void incVisitedCount(int count)
      Specified by:
      incVisitedCount in interface KnnCollector
      Parameters:
      count - increments the visited vector count, must be greater than 0.

    • visitedCount

      public long visitedCount()
      Specified by:
      visitedCount in interface KnnCollector
      Returns:
      the current visited vector count

    • visitLimit

      public long visitLimit()
      Specified by:
      visitLimit in interface KnnCollector
      Returns:
      the visited vector limit

    • k

      public int k()
      Specified by:
      k in interface KnnCollector
      Returns:
      the expected number of collected results

    • collect

      public boolean collect(int docId, float similarity)
      Description copied from interface: KnnCollector
      Collect the provided docId and include in the result set.
      Specified by:
      collect in interface KnnCollector
      Parameters:
      docId - of the vector to collect
      similarity - its calculated similarity
      Returns:
      true if the vector is collected

    • minCompetitiveSimilarity

      public float minCompetitiveSimilarity()
      Description copied from interface: KnnCollector
      This method is utilized during search to ensure only competitive results are explored.

      Consequently, if this results collector wants to collect `k` results, this should return Float.NEGATIVE_INFINITY when not full.

      When full, the minimum score should be returned.

      Specified by:
      minCompetitiveSimilarity in interface KnnCollector
      Returns:
      the current minimum competitive similarity in the collection

    • topDocs

      public TopDocs topDocs()
      Description copied from interface: KnnCollector
      This drains the collected nearest kNN results and returns them in a new TopDocs collection, ordered by score descending. NOTE: This is generally a destructive action and the collector should not be used after topDocs() is called.
      Specified by:
      topDocs in interface KnnCollector
      Returns:
      The collected top documents