Class HDTTriplesSectionBitmap

  • All Implemented Interfaces:
    java.util.Iterator<int[]>

    class HDTTriplesSectionBitmap
    extends HDTTriplesSection
    HDT Triples section.

    This part contains two levels of bitmaps and arrays.

    Typically (in SPO order), the Y-level corresponds to the predicates and the Z-level to the objects.

    The X (subjects) is implicit since triples are already ordered by X, and bitmap Y is used to notify when there is a new X: X will be used until a 1 is found in bitmap Y, which indicates that the next triple uses X+1.

    The array contains numeric references to the predicates and objects in the HDT dictionaries, starting with the entries in the "shared" Dictionary These positions are counted starting with 1, not 0.

    E.g. Y-bitmap 0 1 1 and Y-array 1 2 3 results in S1-P1 S1-P2 S2-P3

    Structure:

     +----------+----------+---------+---------+
     | Bitmap Y | Bitmap Z | Array Y | Array Z |
     +----------+----------+---------+---------+
     
    • Field Detail

      • sizeY

        private int sizeY
      • sizeZ

        private int sizeZ
      • posX

        private int posX
      • posY

        private int posY
      • posZ

        private int posZ
    • Constructor Detail

      • HDTTriplesSectionBitmap

        HDTTriplesSectionBitmap()
    • Method Detail

      • hasNext

        public boolean hasNext()
      • next

        public int[] next()
      • parse

        protected void parse​(java.io.InputStream is)
                      throws java.io.IOException
        Description copied from class: HDTPart
        Parse from input stream
        Specified by:
        parse in class HDTPart
        Throws:
        java.io.IOException
      • parse

        protected void parse​(java.io.InputStream is,
                             HDTTriples.Order order)
                      throws java.io.IOException
        Description copied from class: HDTTriplesSection
        Parse triples section and return the triple parts in the correct S,P,O order.
        Specified by:
        parse in class HDTTriplesSection
        Throws:
        java.io.IOException