Package org.apache.datasketches.theta

Class Intersection

java.lang.Object
org.apache.datasketches.theta.SetOperation
org.apache.datasketches.theta.Intersection
All Implemented Interfaces:
MemoryStatus
public abstract class Intersection extends SetOperation
The API for intersection operations
Author:
Lee Rhodes

  • Constructor Details

    • Intersection

      public Intersection()

  • Method Details

    • getFamily

      public Family getFamily()
      Description copied from class: SetOperation
      Gets the Family of this SetOperation
      Specified by:
      getFamily in class SetOperation
      Returns:
      the Family of this SetOperation

    • getResult

      public CompactSketch getResult()
      Gets the result of this operation as an ordered CompactSketch on the Java heap. This does not disturb the underlying data structure of this intersection. The intersect(Sketch) method must have been called at least once, otherwise an exception will be thrown. This is because a virgin Intersection object represents the Universal Set, which has an infinite number of values.
      Returns:
      the result of this operation as an ordered CompactSketch on the Java heap

    • getResult

      public abstract CompactSketch getResult(boolean dstOrdered, org.apache.datasketches.memory.WritableMemory dstMem)
      Gets the result of this operation as a CompactSketch in the given dstMem. This does not disturb the underlying data structure of this intersection. The intersect(Sketch) method must have been called at least once, otherwise an exception will be thrown. This is because a virgin Intersection object represents the Universal Set, which has an infinite number of values.

      Note that presenting an intersection with an empty sketch sets the internal state of the intersection to empty = true, and current count = 0. This is consistent with the mathematical definition of the intersection of any set with the empty set is always empty.

      Presenting an intersection with a null argument will throw an exception.

      Parameters:
      dstOrdered - See Destination Ordered
      dstMem - See Destination Memory.
      Returns:
      the result of this operation as a CompactSketch stored in the given dstMem, which can be either on or off-heap..

    • hasResult

      public abstract boolean hasResult()
      Returns true if there is a valid intersection result available
      Returns:
      true if there is a valid intersection result available

    • reset

      public abstract void reset()
      Resets this Intersection for stateful operations only. The seed remains intact, otherwise reverts to the Universal Set: theta = 1.0, no retained data and empty = false.

    • toByteArray

      public abstract byte[] toByteArray()
      Serialize this intersection to a byte array form.
      Returns:
      byte array of this intersection

    • intersect

      public abstract void intersect(Sketch sketchIn)
      Intersect the given sketch with the internal state. This method can be repeatedly called. If the given sketch is null the internal state becomes the empty sketch. Theta will become the minimum of thetas seen so far.
      Parameters:
      sketchIn - the given sketch

    • intersect

      public CompactSketch intersect(Sketch a, Sketch b)
      Perform intersect set operation on the two given sketch arguments and return the result as an ordered CompactSketch on the heap.
      Parameters:
      a - The first sketch argument
      b - The second sketch argument
      Returns:
      an ordered CompactSketch on the heap

    • intersect

      public abstract CompactSketch intersect(Sketch a, Sketch b, boolean dstOrdered, org.apache.datasketches.memory.WritableMemory dstMem)
      Perform intersect set operation on the two given sketches and return the result as a CompactSketch.
      Parameters:
      a - The first sketch argument
      b - The second sketch argument
      dstOrdered - See Destination Ordered.
      dstMem - See Destination Memory.
      Returns:
      the result as a CompactSketch.