Package org.apache.lucene.codecs

Class KnnVectorsWriter.MergedVectorValues

  • Enclosing class:
    KnnVectorsWriter
    protected static class KnnVectorsWriter.MergedVectorValues
extends VectorValues
    View over multiple VectorValues supporting iterator-style access via DocIdMerger.

    • Method Detail

      • vectorValue

        public float[] vectorValue()
                    throws IOException
        Description copied from class: VectorValues
        Return the vector value for the current document ID. It is illegal to call this method when the iterator is not positioned: before advancing, or after failing to advance. The returned array may be shared across calls, re-used, and modified as the iterator advances.
        Specified by:
        vectorValue in class VectorValues
        Returns:
        the vector value
        Throws:
        IOException

      • binaryValue

        public BytesRef binaryValue()
                     throws IOException
        Description copied from class: VectorValues
        Return the binary encoded vector value for the current document ID. These are the bytes corresponding to the float array return by VectorValues.vectorValue(). It is illegal to call this method when the iterator is not positioned: before advancing, or after failing to advance. The returned storage may be shared across calls, re-used and modified as the iterator advances.
        Overrides:
        binaryValue in class VectorValues
        Returns:
        the binary value
        Throws:
        IOException

      • advance

        public int advance​(int target)
        Description copied from class: DocIdSetIterator
        Advances to the first beyond the current whose document number is greater than or equal to target, and returns the document number itself. Exhausts the iterator and returns DocIdSetIterator.NO_MORE_DOCS if target is greater than the highest document number in the set.

        The behavior of this method is undefined when called with target ≤ current , or after the iterator has exhausted. Both cases may result in unpredicted behavior.

        When target > current it behaves as if written: 

         int advance(int target) {
   int doc;
   while ((doc = nextDoc()) < target) {
   }
   return doc;
 }
        Some implementations are considerably more efficient than that.

        NOTE: this method may be called with DocIdSetIterator.NO_MORE_DOCS for efficiency by some Scorers. If your implementation cannot efficiently determine that it should exhaust, it is recommended that you check for that value in each call to this method.

        Specified by:
        advance in class DocIdSetIterator

      • size

        public int size()
        Description copied from class: VectorValues
        TODO: should we use cost() for this? We rely on its always being exactly the number of documents having a value for this field, which is not guaranteed by the cost() contract, but in all the implementations so far they are the same.
        Specified by:
        size in class VectorValues
        Returns:
        the number of vectors returned by this iterator

      • cost

        public long cost()
        Description copied from class: DocIdSetIterator
        Returns the estimated cost of this DocIdSetIterator.

        This is generally an upper bound of the number of documents this iterator might match, but may be a rough heuristic, hardcoded value, or otherwise completely inaccurate.

        Specified by:
        cost in class DocIdSetIterator

      • dimension

        public int dimension()
        Description copied from class: VectorValues
        Return the dimension of the vectors
        Specified by:
        dimension in class VectorValues