class CheckoutLane(Component):
base_name = 'lane'
def __init__(self, *args, **kwargs):
super(CheckoutLane, self).__init__(*args, **kwargs)
self.queue = Queue(self.env)
self.auto_probe('queue', vcd={})
self.add_process(self.checkout)
def __lt__(self, other):
return self.queue.size < other.queue.size
def enqueue(self, num_items, done_event):
return self.queue.put((num_items, done_event))
def checkout(self):
scan_dist = partial(self.env.rand.expovariate,
1 / self.env.config['grocery.scan_time'])
while True:
num_items, done_event = yield self.queue.get()
for n in range(num_items):
yield self.env.timeout(scan_dist())
done_event.succeed()
class TankerTruck(Component):
"""Tanker trucks carry fuel to gas stations.
Each tanker truck has a queue of gas stations it must visit. When the
truck's tank becomes empty, it must go refill itself.
"""
base_name = 'truck'
def __init__(self, *args, **kwargs):
super(TankerTruck, self).__init__(*args, **kwargs)
self.pump_rate = self.env.config.get('tanker.pump_rate', 10)
self.avg_travel = self.env.config.get('tanker.travel_time', 600)
tank_capacity = self.env.config.get('tanker.capacity', 200)
self.tank = Container(self.env, tank_capacity)
# This auto_probe() call causes the self.tank Container to be
# monkey-patched such that whenever it's level changes, the new level
# is noted in the log.
self.auto_probe('tank', log={})
# The parent TankerCompany enqueues instructions to this queue.
self._instructions = Queue(self.env)
# Declare a persistant process to be started at simulation-time.
self.add_process(self._dispatch_loop)
def dispatch(self, gas_station, done_event):
"""Append dispatch instructions to the truck's queue."""
return self._instructions.put((gas_station, done_event))
def _dispatch_loop(self):
"""This is the tanker truck's main behavior. Travel, pump, refill..."""
while True:
if not self.tank.level:
self.info('going for refill')
# Desmod simulation environments come equipped with a
# random.Random() instance seeded based on the 'sim.seed'
# configuration key.
travel_time = self.env.rand.expovariate(1 / self.avg_travel)
yield self.env.timeout(travel_time)
self.info('refilling')
pump_time = self.tank.capacity / self.pump_rate
yield self.env.timeout(pump_time)
yield self.tank.put(self.tank.capacity)
self.info('refilled {}L in {:.0f}s'.format(
self.tank.capacity, pump_time))
gas_station, done_event = yield self._instructions.get()
self.info('traveling to {}'.format(gas_station.name))
travel_time = self.env.rand.expovariate(1 / self.avg_travel)
yield self.env.timeout(travel_time)
self.info('arrived at {}'.format(gas_station.name))
while self.tank.level and (gas_station.reservoir.level <
gas_station.reservoir.capacity):
yield self.env.timeout(1 / self.pump_rate)
yield gas_station.reservoir.put(1)
yield self.tank.get(1)
self.info('done pumping')
done_event.succeed()
class TankerTruck(Component):
"""Tanker trucks carry fuel to gas stations.
Each tanker truck has a queue of gas stations it must visit. When the
truck's tank becomes empty, it must go refill itself.
"""
base_name = 'truck'
def __init__(self, *args, **kwargs):
super(TankerTruck, self).__init__(*args, **kwargs)
self.pump_rate = self.env.config.get('tanker.pump_rate', 10)
self.avg_travel = self.env.config.get('tanker.travel_time', 600)
tank_capacity = self.env.config.get('tanker.capacity', 200)
self.tank = Container(self.env, tank_capacity)
# This auto_probe() call causes the self.tank Container to be
# monkey-patched such that whenever it's level changes, the new level
# is noted in the log.
self.auto_probe('tank', log={})
# The parent TankerCompany enqueues instructions to this queue.
self._instructions = Queue(self.env)
# Declare a persistant process to be started at simulation-time.
self.add_process(self._dispatch_loop)
def dispatch(self, gas_station, done_event):
"""Append dispatch instructions to the truck's queue."""
return self._instructions.put((gas_station, done_event))
def _dispatch_loop(self):
"""This is the tanker truck's main behavior. Travel, pump, refill..."""
while True:
if not self.tank.level:
self.info('going for refill')
# Desmod simulation environments come equipped with a
# random.Random() instance seeded based on the 'sim.seed'
# configuration key.
travel_time = self.env.rand.expovariate(1 / self.avg_travel)
yield self.env.timeout(travel_time)
self.info('refilling')
pump_time = self.tank.capacity / self.pump_rate
yield self.env.timeout(pump_time)
yield self.tank.put(self.tank.capacity)
self.info('refilled {}L in {:.0f}s'.format(
self.tank.capacity, pump_time))
gas_station, done_event = yield self._instructions.get()
self.info('traveling to {}'.format(gas_station.name))
travel_time = self.env.rand.expovariate(1 / self.avg_travel)
yield self.env.timeout(travel_time)
self.info('arrived at {}'.format(gas_station.name))
while self.tank.level and (gas_station.reservoir.level <
gas_station.reservoir.capacity):
yield self.env.timeout(1 / self.pump_rate)
yield gas_station.reservoir.put(1)
yield self.tank.get(1)
self.info('done pumping')
done_event.succeed()