Rework lidar to better support testing and listeners.

Messaging/message_factory.py

@@ -8,13 +8,11 @@ class ZmqPubSubStreamer:
     '''
 
     def __init__(self, port):
-        # Should create the socket here always, since zmq is not thread safe.
-        # Hopefully whoever uses this is not stupid enough to create it then
-        # pass it into a thread.
         self._socket = zmq.Context.instance().socket(zmq.PUB)
         print('Starting socket with address: ' + 'tcp://*:' + str(port))
         self._socket.bind("tcp://*:" + str(port))
         
+
     def send_message(self, message):
         '''
         Args

requirements.txt

@@ -5,3 +5,4 @@ paho-mqtt
 u-msgpack-python
 grpcio-tools
 rplidar
+pyzmq

tracking/lidar_cache.py

@@ -4,7 +4,6 @@ from threading import Thread
 from tracking import algorithms
 import tracking.lidar_tracker_pb2 as tracker_pb
 import zmq
-import Messaging.message_factory as mf
 import Messaging.messages as messages
 
 
@@ -14,31 +13,27 @@ class LidarCache():
     runs grouping algorithms between scans and 
     keeps a copy of the group data.
     '''
-    run = True
-    tracking_group_number = -1
-    currentGroups = None
-    groupsChanged = []
-    port = None
 
     def __init__(self, measurements=100):
         self.lidar = RPLidar('/dev/ttyUSB0')
         self.measurements = measurements
         print('Info: ' + self.lidar.get_info())
         print('Health: ' + self.lidar.get_health())
+        self.run = True
+        self.tracking_group_number = -1
+        self.currentGroups = None
+        self.groupsChanged = []
 
-    def start_cache(self):
+    def start_cache(self, sender):
-        if self.port is None:
+        self.thread = Thread(target=self.do_scanning, args=[sender])
-            print('ERROR: Port has not been set!')
-            return
-        self.thread = Thread(target=self.do_scanning)
         self.thread.start()
 
-    def do_scanning(self):
+    def do_scanning(self, sender):
         '''
         Performs a scan for the given number of iterations.
         '''
         # Create the 0MQ socket first. This should not be passed between threads.
-        self._mFactory = mf.getZmqPubSubStreamer(self.port)
+        self._mFactory = sender
 
         for i, scan in enumerate(self.lidar.iter_scans(min_len=self.measurements)):
             print('%d: Got %d measurments' % (i, len(scan)))
@@ -54,6 +49,7 @@ class LidarCache():
 
     def fireGroupsChanged(self):
         # Send the updated groups to 0MQ socket.
+        # Rename this to be a generic listener method, rather than an explicit 'send' (even though it can be treated as such already)
         self._mFactory.send_message_topic("lidar_map", messages.ProtoMessage(
             message=tracker_pb.PointScan(points=[]).SerializeToString()))
 

tracking/lidar_servicer.py

@@ -2,6 +2,7 @@ import tracking.lidar_tracker_pb2 as lidar_tracker_pb2
 from tracking.lidar_tracker_pb2_grpc import PersonTrackingServicer
 from tracking.lidar_cache import LidarCache
 from multiprocessing import Process
+import Messaging.message_factory as mf
 
 
 class LidarServicer(PersonTrackingServicer):
@@ -19,4 +20,4 @@ class LidarServicer(PersonTrackingServicer):
         '''
         Starts the lidar cache. 
         '''
-        self.cache.start_cache()
+        self.cache.start_cache(mf.getZmqPubSubStreamer(request.value))