Package org.apache.lucene.codecs.perfield

Class PerFieldKnnVectorsFormat.FieldsReader

java.lang.Object
org.apache.lucene.codecs.KnnVectorsReader
org.apache.lucene.codecs.perfield.PerFieldKnnVectorsFormat.FieldsReader
All Implemented Interfaces:
Closeable, AutoCloseable, Accountable
Enclosing class:
PerFieldKnnVectorsFormat
public static class PerFieldKnnVectorsFormat.FieldsReader extends KnnVectorsReader
VectorReader that can wrap multiple delegate readers, selected by field.

  • Constructor Details

    • FieldsReader

      public FieldsReader(SegmentReadState readState) throws IOException
      Create a FieldsReader over a segment, opening VectorReaders for each KnnVectorsFormat specified by the indexed numeric vector fields.
      Parameters:
      readState - defines the fields
      Throws:
      IOException - if one of the delegate readers throws

  • Method Details

    • getFieldReader

      public KnnVectorsReader getFieldReader(String field)
      Return the underlying VectorReader for the given field
      Parameters:
      field - the name of a numeric vector field

    • checkIntegrity

      public void checkIntegrity() throws IOException
      Description copied from class: KnnVectorsReader
      Checks consistency of this reader.

      Note that this may be costly in terms of I/O, e.g. may involve computing a checksum value against large data files.

      Specified by:
      checkIntegrity in class KnnVectorsReader
      Throws:
      IOException

    • getVectorValues

      public VectorValues getVectorValues(String field) throws IOException
      Description copied from class: KnnVectorsReader
      Returns the VectorValues for the given field. The behavior is undefined if the given field doesn't have KNN vectors enabled on its FieldInfo. The return value is never null.
      Specified by:
      getVectorValues in class KnnVectorsReader
      Throws:
      IOException

    • search

      public TopDocs search(String field, float[] target, int k, Bits acceptDocs, int visitedLimit) throws IOException
      Description copied from class: KnnVectorsReader
      Return the k nearest neighbor documents as determined by comparison of their vector values for this field, to the given vector, by the field's similarity function. The score of each document is derived from the vector similarity in a way that ensures scores are positive and that a larger score corresponds to a higher ranking.

      The search is allowed to be approximate, meaning the results are not guaranteed to be the true k closest neighbors. For large values of k (for example when k is close to the total number of documents), the search may also retrieve fewer than k documents.

      The returned TopDocs will contain a ScoreDoc for each nearest neighbor, in order of their similarity to the query vector (decreasing scores). The TotalHits contains the number of documents visited during the search. If the search stopped early because it hit visitedLimit, it is indicated through the relation TotalHits.Relation.GREATER_THAN_OR_EQUAL_TO.

      The behavior is undefined if the given field doesn't have KNN vectors enabled on its FieldInfo. The return value is never null.

      Specified by:
      search in class KnnVectorsReader
      Parameters:
      field - the vector field to search
      target - the vector-valued query
      k - the number of docs to return
      acceptDocs - Bits that represents the allowed documents to match, or null if they are all allowed to match.
      visitedLimit - the maximum number of nodes that the search is allowed to visit
      Returns:
      the k nearest neighbor documents, along with their (searchStrategy-specific) scores.
      Throws:
      IOException

    • close

      public void close() throws IOException
      Throws:
      IOException

    • ramBytesUsed

      public long ramBytesUsed()
      Description copied from interface: Accountable
      Return the memory usage of this object in bytes. Negative values are illegal.