Package org.apache.lucene.search

Interface KnnCollector

All Known Implementing Classes:
AbstractKnnCollector, HnswGraphBuilder.GraphBuilderKnnCollector, OrdinalTranslatedKnnCollector, TopKnnCollector
public interface KnnCollector
KnnCollector is a knn collector used for gathering kNN results and providing topDocs from the gathered neighbors
WARNING: This API is experimental and might change in incompatible ways in the next release.

  • Method Summary

    Modifier and Type
    Method
    Description
    boolean
    collect(int docId, float similarity)
    Collect the provided docId and include in the result set.
    boolean
    earlyTerminated()
    If search visits too many documents, the results collector will terminate early.
    void
    incVisitedCount(int count)
     
    int
    k()
     
    float
    minCompetitiveSimilarity()
    This method is utilized during search to ensure only competitive results are explored.
    TopDocs
    topDocs()
    This drains the collected nearest kNN results and returns them in a new TopDocs collection, ordered by score descending.
    long
    visitedCount()
     
    long
    visitLimit()
     

  • Method Details

    • earlyTerminated

      boolean earlyTerminated()
      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.

      Returns:
      is the current result set marked as incomplete?

    • incVisitedCount

      void incVisitedCount(int count)
      Parameters:
      count - increments the visited vector count, must be greater than 0.

    • visitedCount

      long visitedCount()
      Returns:
      the current visited vector count

    • visitLimit

      long visitLimit()
      Returns:
      the visited vector limit

    • k

      int k()
      Returns:
      the expected number of collected results

    • collect

      boolean collect(int docId, float similarity)
      Collect the provided docId and include in the result set.
      Parameters:
      docId - of the vector to collect
      similarity - its calculated similarity
      Returns:
      true if the vector is collected

    • minCompetitiveSimilarity

      float minCompetitiveSimilarity()
      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.

      Returns:
      the current minimum competitive similarity in the collection

    • topDocs

      TopDocs topDocs()
      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.
      Returns:
      The collected top documents