Method And

roaring64/roaring64.go:438–485

And computes the intersection between two bitmaps and stores the result in the current bitmap

(x2 *Bitmap)

// And computes the intersection between two bitmaps and stores the result in the current bitmap
func (rb *Bitmap) And(x2 *Bitmap) {
	pos1 := 0
	pos2 := 0
	intersectionsize := 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.getWritableContainerAtIndex(pos1)
					c2 := x2.highlowcontainer.getContainerAtIndex(pos2)
					c1.And(c2)
					if !c1.IsEmpty() {
						rb.highlowcontainer.replaceKeyAndContainerAtIndex(intersectionsize, s1, c1, false)
						intersectionsize++
					}
					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
		}
	}
	rb.highlowcontainer.resize(intersectionsize)
}

// OrCardinality returns the cardinality of the union between two bitmaps, bitmaps are not modified
func (rb *Bitmap) OrCardinality(x2 *Bitmap) uint64 {