def before_request():
""" Before each client request is processed, refresh the session.
If the session is new, instantiate a BOS for the client.
Note: Each session gets its own sandbox. I.e. it's own BOS and sims.
so that each web client can have it's own "sandbox" BOS.
"""
global bos_sessions
def refresh_sess():
bos_web.permanent_session_lifetime = timedelta(minutes=WEB_EXPIRE)
flask.session.permanent = True
flask.session.modified = True
# TODO: Test timeout
# If session exists, refresh it to prevent expire
bos_ID = flask.session.get('bos_id')
if bos_ID and bos_sessions.get(bos_ID):
# print('Request from existing client received: ' + str(bos_ID)) # debug
refresh_sess()
# Else, init a new BOS & flag session as dirty so change is registered.
# The association is necessary because the BOS obj is not serializable.
else:
# Init a new boss associated with a random 16 bit ID
bos_ID = randrange(65536)
bos_sessions[bos_ID] = BOS()
bos_sessions[bos_ID].start()
sleep(.5) # Ample time to start
# Associate session with it's BOS
flask.session['bos_id'] = bos_ID
refresh_sess()
bos_log.info('New client session started: ' + str(bos_ID))
def run(self):
""" Checks msg broker for new status msgs every REFRESH_TIME sec.
"""
bos_log.info('Starting Sandbox...')
self.broker_sim.start()
self.track_sim.start()
bos_log.info('BOS Started.')
while True:
# Fetch the next available status msg, if any
msg = None
try:
msg = self.msg_client.fetch_next_msg(BOS_EMP)
except Queue.Empty:
bos_log.info('Msg queue empty.')
except Exception:
bos_log.warn('Could not connect to broker.')
# Process loco status msg. Msg should be of form given in
# docs/app_messaging_spec.md, Msg ID 6000.
if msg and msg.msg_type == 6000:
try:
locoID = msg.payload['loco']
location = Location(msg.payload['milepost'],
msg.payload['lat'],
msg.payload['long'])
active_conns = eval(msg.payload['conns']) # evals to dict
# Eiter reference or instantiate loco with the given ID
loco = self.track.locos.get(locoID)
if not loco:
loco = Loco(locoID, self.track)
# Update the BOS's loco object with status msg params
loco.update(msg.payload['speed'], msg.payload['heading'],
msg.payload['direction'], location,
msg.payload['bpp'], active_conns)
# Update the last seen time for this loco
self.track.set_lastseen(loco)
bos_log.info('Processed status msg for ' + loco.name)
except KeyError:
bos_log.error('Malformed status msg: ' + str(msg.payload))
elif msg:
bos_log.error('Fetched unhandled msg type: ' +
str(msg.msg_type))
sleep(REFRESH_TIME)
def main_set_sessionvar_async():
""" Accepts a key value pair via ajax and updates session[key] with the
given value. Key must be in PUBLIC_SESSVARS, for safety.
"""
try:
key = flask.request.json['key']
newval = flask.request.json['value']
if key in PUBLIC_SESSVARS:
flask.session[key] = newval
bos_log.info('Set: ' + key + '=' + str(newval))
# Update time sim if that var was updated
if key == 'time_iplier':
try:
bos_sessions[flask.session['bos_id']].set_tplier(newval)
except:
return 'BOS association failure. Try restarting your browser.'
else:
return 'ERROR'
return 'OK'
except Exception as e:
bos_log.error(e)
return 'ERROR: + ' + str(e)