Function array_contains_nulls

src/backend/utils/adt/arrayfuncs.c:3657–3692

* array_contains_nulls --- detect whether an array has any null elements * * This gives an accurate answer, whereas testing ARR_HASNULL only tells * if the array *might* contain a null. */

 * if the array *might* contain a null.
 */
bool
array_contains_nulls(ArrayType *array)
{
	int			nelems;
	bits8	   *bitmap;
	int			bitmask;

	/* Easy answer if there's no null bitmap */
	if (!ARR_HASNULL(array))
		return false;

	nelems = ArrayGetNItems(ARR_NDIM(array), ARR_DIMS(array));

	bitmap = ARR_NULLBITMAP(array);

	/* check whole bytes of the bitmap byte-at-a-time */
	while (nelems >= 8)
	{
		if (*bitmap != 0xFF)
			return true;
		bitmap++;
		nelems -= 8;
	}

	/* check last partial byte */
	bitmask = 1;
	while (nelems > 0)
	{
		if ((*bitmap & bitmask) == 0)
			return true;
		bitmask <<= 1;
		nelems--;
	}

	return false;
}


/*