Add geometry/range functions to support BRIN inclusion

This commit adds the following functions:
    box(point) -> box
    bound_box(box, box) -> box
    inet_same_family(inet, inet) -> bool
    inet_merge(inet, inet) -> cidr
    range_merge(anyrange, anyrange) -> anyrange

The first of these is also used to implement a new assignment cast from
point to box.

These functions are the first part of a base to implement an "inclusion"
operator class for BRIN, for multidimensional data types.

Author: Emre Hasegeli
Reviewed by: Andreas Karlsson

1 files changed, 39 insertions, 0 deletions

diff --git a/src/backend/utils/adt/geo_ops.c b/src/backend/utils/adt/geo_ops.c
index 6cb6be5c5fd..39a78552410 100644
--- a/src/backend/utils/adt/geo_ops.c
+++ b/src/backend/utils/adt/geo_ops.c
@@ -4227,6 +4227,45 @@ box_div(PG_FUNCTION_ARGS)
 	PG_RETURN_BOX_P(result);
 }
 
+/*
+ * Convert point to empty box
+ */
+Datum
+point_box(PG_FUNCTION_ARGS)
+{
+	Point	   *pt = PG_GETARG_POINT_P(0);
+	BOX		   *box;
+
+	box = (BOX *) palloc(sizeof(BOX));
+
+	box->high.x = pt->x;
+	box->low.x = pt->x;
+	box->high.y = pt->y;
+	box->low.y = pt->y;
+
+	PG_RETURN_BOX_P(box);
+}
+
+/*
+ * Smallest bounding box that includes both of the given boxes
+ */
+Datum
+boxes_bound_box(PG_FUNCTION_ARGS)
+{
+	BOX		   *box1 = PG_GETARG_BOX_P(0),
+			   *box2 = PG_GETARG_BOX_P(1),
+			   *container;
+
+	container = (BOX *) palloc(sizeof(BOX));
+
+	container->high.x = Max(box1->high.x, box2->high.x);
+	container->low.x = Min(box1->low.x, box2->low.x);
+	container->high.y = Max(box1->high.y, box2->high.y);
+	container->low.y = Min(box1->low.y, box2->low.y);
+
+	PG_RETURN_BOX_P(container);
+}
+
 
 /***********************************************************************
  **