def apply(tree, parameters=None):
'''
Only supports loops with 2 children!
:param tree:
:return:
'''
net = obj.PetriNet(name=str(tree))
if len(tree.children) == 0:
pn_util.add_transition(net, label=tree.label, name=str(id(tree)))
else:
sub_nets = list()
for c in tree.children:
sub_net, ini, fin = apply(c)
sub_nets.append(sub_net)
pn_util.merge(net, sub_nets)
switch = {
pt_opt.SEQUENCE: construct_sequence_pattern,
pt_opt.XOR: construct_xor_pattern,
pt_opt.PARALLEL: construct_and_pattern,
pt_opt.LOOP: construct_loop_pattern
}
net, ini, fin = switch[tree.operator](net, sub_nets)
if tree.parent is None:
p_ini = pn_util.add_place(net)
p_fin = pn_util.add_place(net)
pn_util.add_arc_from_to(p_ini, _get_src_transition(net), net)
pn_util.add_arc_from_to(_get_sink_transition(net), p_fin, net)
return net, obj.Marking({p_ini: 1}), obj.Marking({p_fin: 1})
return net, obj.Marking(), obj.Marking()
def construct_loop_pattern(net, sub_nets):
assert (len(sub_nets) == 2)
p_s = pn_util.add_place(net)
p_t = pn_util.add_place(net)
pn_util.add_arc_from_to(p_s, _get_src_transition(sub_nets[0]), net)
pn_util.add_arc_from_to(p_t, _get_src_transition(sub_nets[1]), net)
pn_util.add_arc_from_to(_get_sink_transition(sub_nets[0]), p_t, net)
pn_util.add_arc_from_to(_get_sink_transition(sub_nets[1]), p_s, net)
net, ini, fin = _add_src_sink_transitions(net, p_s, p_t)
return net, obj.Marking(), obj.Marking()
def construct_sequence_pattern(net, sub_nets):
places = [None] * (len(sub_nets) + 1)
for i in range(len(sub_nets) + 1):
places[i] = pn_util.add_place(net)
for i in range(len(sub_nets)):
pn_util.add_arc_from_to(places[i], _get_src_transition(sub_nets[i]), net)
pn_util.add_arc_from_to(_get_sink_transition(sub_nets[i]), places[i + 1], net)
src = pn_util.add_transition(net)
pn_util.add_arc_from_to(src, places[0], net)
sink = pn_util.add_transition(net)
pn_util.add_arc_from_to(places[len(places) - 1], sink, net)
return net, obj.Marking(), obj.Marking()
def deepcopy_net():
im = obj.Marking()
fm = obj.Marking()
p_net = copy.deepcopy(settings.PETRI_NET_ORIG)
for place in p_net.places:
for p_ini in settings.I_MARKS_ORIG:
if str(p_ini) == str(place):
im = obj.Marking({place : 1})
for p_f in settings.F_MARKS_ORIG:
if str(p_f) == str(place):
fm = obj.Marking({place : 1})
return p_net, im, fm
def construct_and_pattern(net, sub_nets):
p_s = [None] * len(sub_nets)
p_t = [None] * len(sub_nets)
for i in range(len(sub_nets)):
p_s[i] = pn_util.add_place(net)
p_t[i] = pn_util.add_place(net)
pn_util.add_arc_from_to(p_s[i], _get_src_transition(sub_nets[i]), net)
pn_util.add_arc_from_to(_get_sink_transition(sub_nets[i]), p_t[i], net)
src = pn_util.add_transition(net)
for p in p_s:
pn_util.add_arc_from_to(src, p, net)
sink = pn_util.add_transition(net)
for p in p_t:
pn_util.add_arc_from_to(p, sink, net)
return net, obj.Marking(), obj.Marking()
def check_easy_soundness_of_wfnet(net):
"""
Checks the easy soundness of a workflow net
Parameters
-------------
net
Petri net
Returns
-------------
boolean
Boolean value
"""
source = list(x for x in net.places if len(x.in_arcs) == 0)[0]
sink = list(x for x in net.places if len(x.out_arcs) == 0)[0]
ini = obj.Marking({source: 1})
fin = obj.Marking({sink: 1})
return check_easy_soundness_net_in_fin_marking(net, ini, fin)
def _add_src_sink_transitions(net, p_s, p_t):
src = pn_util.add_transition(net)
pn_util.add_arc_from_to(src, p_s, net)
sink = pn_util.add_transition(net)
pn_util.add_arc_from_to(p_t, sink, net)
return net, obj.Marking(), obj.Marking()