openstack
/
automaton
Code Issues Proposed changes

Allow initialize to take an alternative start_state 

For the cases where it is desireable to force the machine
to start in a state that is not the constructor provided
state allow that to be possible using the initialize method.

By default it performs the existing behavior.
This commit is contained in:
Joshua Harlow 2014-12-10 17:43:20 -08:00
parent eb169daa98
commit 6f1be9d745
1 changed files with 12 additions and 9 deletions
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21
automaton/machines.py
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@ -78,7 +78,7 @@ class FiniteMachine(object):
return cls._Effect(new_state['reactions'].get(event),
new_state["terminal"])
def __init__(self, start_state):
def __init__(self, start_state, add_start=False):
self._transitions = {}
self._states = OrderedDict()
self._start_state = start_state
@ -214,15 +214,17 @@ class FiniteMachine(object):
result = self._effect_builder(self._states[replacement.name], event)
return self._post_process_event(event, result)
def initialize(self):
def initialize(self, start_state=None):
"""Sets up the state machine (sets current state to start state...)."""
if self._start_state not in self._states:
if start_state is None:
start_state = self._start_state
if start_state not in self._states:
raise excp.NotFound("Can not start from a undefined"
" state '%s'" % (self._start_state))
if self._states[self._start_state]['terminal']:
" state '%s'" % (start_state))
if self._states[start_state]['terminal']:
raise excp.InvalidState("Can not start from a terminal"
" state '%s'" % (self._start_state))
self._current = _Jump(self._start_state, None, None)
" state '%s'" % (start_state))
self._current = _Jump(start_state, None, None)
def copy(self, shallow=False, unfreeze=False):
"""Copies the current state machine.
@ -394,8 +396,9 @@ class HierarchicalFiniteMachine(FiniteMachine):
if machine is not None:
self._states[state]['machine'] = machine
def initialize(self):
super(HierarchicalFiniteMachine, self).initialize()
def initialize(self, start_state=None):
super(HierarchicalFiniteMachine, self).initialize(
start_state=start_state)
for data in six.itervalues(self._states):
if 'machine' in data:
data['machine'].initialize()