SDN Programming for Heterogeneous Switches with Flow Table Pipelining

Algorithm 1

Algorithm to recursively compress forwarding tree.

	Parameters: ft: Forwarding Tree
(1)	Procedure CompressFT(ft)
(2)	for node in ft:
(3)	node.compressed = false; /∗ Initialization. ∗/
(4)	Compress(ft.root);
(5)	return;
(6)	def Compress(node): /∗ A depth-first tree traversal. ∗/
(7)	if == Leaf: /∗ Check if node is a leaf. ∗/
(8)	node.compressed = true;
(9)	return
(10)	else:
(11)	for child_t1 in node.children: /∗ Find a child. ∗/
(12)	if child_t1.compressed == false:
(13)	Compress(child_t1); /∗ Recursively compress the child. ∗/
(14)	return;
(15)	for child_t2 in (node.children-child_t1): /∗ Find a child that is the same as child_t1. ∗/
(16)	if child_t2.compressed and child_t1 == child_t2:
(17)	child_t2 points to the same node of child_t1; /∗ Remove redundancies. ∗/
(18)	node.children.delete(child_t2);
(19)	node.compressed = true;
(20)	return