def bus_position(request):
with open(FEED_FILE, 'rb') as feed_file:
feed_message = FeedMessage.FromString(feed_file.read())
latest = 0
coords = None, None
for msg in feed_message.entity:
if msg.vehicle.timestamp > latest:
latest = msg.vehicle.timestamp
coords = msg.vehicle.position.latitude, msg.vehicle.position.longitude
response = HttpResponse(','.join([str(x) for x in coords]), content_type='text/plain')
response['Access-Control-Allow-Origin'] = '*'
return response
def transit_update(request):
data = json.loads(request.body.decode('utf-8'))
try:
with open(FEED_FILE, 'rb') as feed_file:
feed_message = FeedMessage.FromString(feed_file.read())
except IOError:
feed_header = FeedHeader(
gtfs_realtime_version='1.0',
incrementality='FULL_DATASET',
timestamp=int(time.time()),
)
feed_message = FeedMessage(
header=feed_header,
entity=[],
)
message_hash = hashlib.sha256()
for key in sorted(data.keys()):
message_hash.update(str(data[key]))
position = Position(
latitude=float(data['px']),
longitude=float(data['py']),
)
trip_descriptor = TripDescriptor(
trip_id=data['tripid'],
)
vehicle_position = VehiclePosition(
trip=trip_descriptor,
position=position,
timestamp=int(data['ts']) // 1000,
)
feed_entity = FeedEntity(
id=message_hash.hexdigest(),
vehicle=vehicle_position,
)
feed_message.header.timestamp = int(time.time())
feed_message.entity.extend([feed_entity])
to_remove = []
old_enough = datetime.now() - timedelta(minutes=30)
for item in feed_message.entity:
try:
when = datetime.fromtimestamp(item.vehicle.timestamp)
except ValueError:
when = datetime.fromtimestamp(item.vehicle.timestamp // 1000)
if when < old_enough:
to_remove.append(item)
for item in to_remove:
feed_message.entity.remove(item)
with open(FEED_FILE, 'wb') as feed_file:
feed_file.write(feed_message.SerializeToString())
return HttpResponse(feed_message.SerializeToString(), content_type='application/octet-stream')