def slice_node_iso(slice1, slice2):
"""Test if two slices overlap on any switches or hosts.
Note that we can only generally detect hosts by mapping ports.
"""
ports1 = util.ports_of_topo(slice1.l_topo, end_hosts=True)
ports2 = util.ports_of_topo(slice2.l_topo, end_hosts=True)
ports_mapped1 = [slice1.port_map[p] for p in ports1]
ports_mapped2 = [slice2.port_map[p] for p in ports2]
switches1 = set([s for (s, _) in ports_mapped1])
switches2 = set([s for (s, _) in ports_mapped2])
return len(switches1.intersection(switches2)) > 0
def get_slices(n=256):
p_topo = nxtopo.NXTopo()
nodes = {}
# add all the "owned" nodes
for i in range(n):
nodes[i] = set()
for j in range(n):
if i == j:
next
else:
nodes[i].add(j)
p_topo.add_switch(id_of_node(i, j))
# add all the edges
for i in range(n):
for j in nodes[i]:
p_topo.add_link(id_of_node(i, j), id_of_node(j, i))
p_topo.finalize()
# Construct the slices
slices = set()
for i in range(n):
slice_nodes = set()
# owned nodes
slice_nodes.update([id_of_node(i, j) for j in nodes[i]])
# foreign nodes
slice_nodes.update([id_of_node(j, i) for j in nodes[i]])
l_topo = p_topo.subgraph(slice_nodes)
switch_map = util.id_map(slice_nodes)
port_map = util.id_map(util.ports_of_topo(l_topo))
predicate = util.build_external_predicate(l_topo)
slices.add(Slice(l_topo, p_topo, switch_map, port_map, predicate))
return p_topo, slices
def ident_map_slice(topo, edge_policy, map_end_hosts=False):
"""Build a slice using topo as both the physical and logical topology."""
node_map = util.id_map(topo.nodes() if map_end_hosts else topo.switches())
port_map = util.id_map(util.ports_of_topo(topo))
return Slice(topo, topo, node_map, port_map, edge_policy, map_end_hosts)
def get_slices():
p_topo = nxtopo.NXTopo()
# The triangular core
p_topo.add_switch("PI1")
p_topo.add_switch("PI2")
p_topo.add_switch("PI3")
p_topo.add_link("PI1","PI2")
p_topo.add_link("PI1","PI3")
p_topo.add_link("PI2","PI3")
# An external-facing switch for each switch in the core
p_topo.add_switch("PE1")
p_topo.add_switch("PE2")
p_topo.add_switch("PE3")
p_topo.add_link("PI1", "PE1")
p_topo.add_link("PI2", "PE2")
p_topo.add_link("PI3", "PE3")
# For each slice, two endpoints attached appropriately.
# R \ / G
# 1
# / \
# --3---2--
# / \
# B
p_topo.add_host("GH1")
p_topo.add_link("GH1", "PE1")
p_topo.add_host("GH2")
p_topo.add_link("GH2", "PE2")
p_topo.add_host("BH1")
p_topo.add_link("BH1", "PE2")
p_topo.add_host("BH2")
p_topo.add_link("BH2", "PE3")
p_topo.add_host("RH1")
p_topo.add_link("RH1", "PE3")
p_topo.add_host("RH2")
p_topo.add_link("RH2", "PE1")
p_topo.finalize()
green_switches = ("PE1", "PI1", "PI2", "PE2")
blue_switches = ("PE2", "PI2", "PI3", "PE3")
red_switches = ("PE3", "PI3", "PI1", "PE1")
green_hosts = ("GH1", "GH2")
blue_hosts = ("BH1", "BH2")
red_hosts = ("RH1", "RH2")
green_nodes = green_switches + green_hosts
blue_nodes = blue_switches + blue_hosts
red_nodes = red_switches + red_hosts
green_topo = p_topo.subgraph(green_nodes)
blue_topo = p_topo.subgraph(blue_nodes)
red_topo = p_topo.subgraph(red_nodes)
green_ports = util.ports_of_topo(green_topo)
blue_ports = util.ports_of_topo(blue_topo)
red_ports = util.ports_of_topo(red_topo)
g_s_map = util.id_map(green_topo.switches())
b_s_map = util.id_map(blue_topo.switches())
r_s_map = util.id_map(red_topo.switches())
g_p_map = util.id_map(green_ports)
b_p_map = util.id_map(blue_ports)
r_p_map = util.id_map(red_ports)
g_preds = util.build_external_predicate(green_topo)
b_preds = util.build_external_predicate(blue_topo)
r_preds = util.build_external_predicate(red_topo)
green_slice = slicing.Slice(green_topo, p_topo, g_s_map, g_p_map, g_preds)
blue_slice = slicing.Slice(blue_topo, p_topo, b_s_map, b_p_map, b_preds)
red_slice = slicing.Slice(red_topo, p_topo, r_s_map, r_p_map, r_preds)
return p_topo, (green_slice, blue_slice, red_slice)