Method AndCardinality

roaring.go:1470–1513

AndCardinality returns the cardinality of the intersection between two bitmaps, bitmaps are not modified

(x2 *Bitmap)

// AndCardinality returns the cardinality of the intersection between two bitmaps, bitmaps are not modified
func (rb *Bitmap) AndCardinality(x2 *Bitmap) uint64 {
	pos1 := 0
	pos2 := 0
	answer := uint64(0)
	length1 := rb.highlowcontainer.size()
	length2 := x2.highlowcontainer.size()

main:
	for {
		if pos1 < length1 && pos2 < length2 {
			s1 := rb.highlowcontainer.getKeyAtIndex(pos1)
			s2 := x2.highlowcontainer.getKeyAtIndex(pos2)
			for {
				if s1 == s2 {
					c1 := rb.highlowcontainer.getContainerAtIndex(pos1)
					c2 := x2.highlowcontainer.getContainerAtIndex(pos2)
					answer += uint64(c1.andCardinality(c2))
					pos1++
					pos2++
					if (pos1 == length1) || (pos2 == length2) {
						break main
					}
					s1 = rb.highlowcontainer.getKeyAtIndex(pos1)
					s2 = x2.highlowcontainer.getKeyAtIndex(pos2)
				} else if s1 < s2 {
					pos1 = rb.highlowcontainer.advanceUntil(s2, pos1)
					if pos1 == length1 {
						break main
					}
					s1 = rb.highlowcontainer.getKeyAtIndex(pos1)
				} else { // s1 > s2
					pos2 = x2.highlowcontainer.advanceUntil(s1, pos2)
					if pos2 == length2 {
						break main
					}
					s2 = x2.highlowcontainer.getKeyAtIndex(pos2)
				}
			}
		} else {
			break
		}
	}
	return answer
}

// IntersectsWithInterval checks whether a bitmap 'rb' and an open interval '[x,y)' intersect.
func (rb *Bitmap) IntersectsWithInterval(x, y uint64) bool {