57 lines
1.6 KiB
Python
57 lines
1.6 KiB
Python
from collections import defaultdict, namedtuple
|
|
from threading import RLock
|
|
from datetime import datetime
|
|
|
|
from app.EventBus import Event
|
|
from app.util import ensure_list, matcher
|
|
|
|
EVENT_STATE_CHANGED = "state_changed"
|
|
|
|
state = namedtuple("State", ['state','last_changed'])
|
|
|
|
class StateMachine:
|
|
|
|
def __init__(self, eventBus):
|
|
self.states = dict()
|
|
self.eventBus = eventBus
|
|
self.lock = RLock()
|
|
|
|
def add_category(self, category, initialState):
|
|
self.states[category] = state(initialState, datetime.now())
|
|
|
|
def set_state(self, category, newState):
|
|
self.lock.acquire()
|
|
|
|
assert category in self.states, "Category does not exist: {}".format(category)
|
|
|
|
oldState = self.states[category]
|
|
|
|
if oldState.state != newState:
|
|
self.states[category] = state(newState, datetime.now())
|
|
|
|
self.eventBus.fire(Event(EVENT_STATE_CHANGED, {'category':category, 'oldState':oldState, 'newState':self.states[category]}))
|
|
|
|
self.lock.release()
|
|
|
|
def get_state(self, category):
|
|
assert category in self.states, "Category does not exist: {}".format(category)
|
|
|
|
return self.states[category]
|
|
|
|
|
|
def track_state_change(eventBus, category, fromState, toState, action):
|
|
fromState = ensure_list(fromState)
|
|
toState = ensure_list(toState)
|
|
|
|
def listener(event):
|
|
assert isinstance(event, Event), "event needs to be of Event type"
|
|
|
|
if category == event.data['category'] and \
|
|
matcher(event.data['oldState'].state, fromState) and \
|
|
matcher(event.data['newState'].state, toState):
|
|
|
|
action(event.data['category'], event.data['oldState'], event.data['newState'])
|
|
|
|
eventBus.listen(EVENT_STATE_CHANGED, listener)
|
|
|