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