initial commit

AbstractTrajectorySimulatorBase.py

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+""" Abstract base class for a trajectory simulation
+
+This class provides basic services that will generate and feed broadcasting
+thread with appropriate messages.
+
+2 abstract methods need to be overriden in derived classes :
+- refresh_delay which should return the simulation timestep in seconds
+- update_aircraftinfos which is reponsible for animating the aircraftinfos
+  object at each time step, thus making the simulation "alive"
+
+mutex protection occurs when calling replace_message
+
+This program is free software: you can redistribute it and/or modify it under
+the terms of the GNU General Public License as published by the Free Software
+Foundation, either version 3 of the License, or (at your option) any later
+version.
+This program is distributed in the hope that it will be useful, but WITHOUT
+ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
+FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.
+You should have received a copy of the GNU General Public License along with
+this program. If not, see <http://www.gnu.org/licenses/>.
+"""
+
+import time
+import abc
+import threading
+
+from ModeS import ModeS
+
+class AbstractTrajectorySimulatorBase(threading.Thread,abc.ABC):
+    def __init__(self,mutex,broadcast_thread,aircraftinfos):
+        super().__init__()
+        self._mutex = mutex
+        self._broadcast_thread = broadcast_thread
+        self._aircraftinfos = aircraftinfos
+
+        self._modeSencoder = ModeS(df=17,icao=self._aircraftinfos.icao,ca=self._aircraftinfos.capability)
+
+        self._do_stop = False
+    
+    # Thread core function
+    def run(self):
+
+        is_first_step = True
+        while not self._do_stop:
+            encoder_changed = False
+            # check if modeS encoder needs update
+            if self._aircraftinfos.icao_changed or self._aircraftinfos.capability_changed or is_first_step:
+                self._modeSencoder.icao = self._aircraftinfos.icao
+                self._modeSencoder.ca = self._aircraftinfos.capability
+                encoder_changed = True
+
+            if encoder_changed or self._aircraftinfos.callsign_changed:
+                self.df_callsign = self._modeSencoder.callsign_encode(self._aircraftinfos.callsign)        
+                self._broadcast_thread.replace_message("identification",self.df_callsign)
+
+            if encoder_changed or self._aircraftinfos.squawk_changed:
+                self.frame_6116 = self._modeSencoder.modaA_encode(self._aircraftinfos.squawk)
+                self._broadcast_thread.replace_message("register_6116",self.frame_6116)
+
+            # message generation only if needed
+            if encoder_changed or self._aircraftinfos.on_surface_changed \
+                or self._aircraftinfos.lat_changed or self._aircraftinfos.lon_changed or self._aircraftinfos.alt_msl_changed \
+                or self._aircraftinfos.type_code_changed or self._aircraftinfos.surveillance_status_changed or self._aircraftinfos.nicsupb_changed \
+                or self._aircraftinfos.timesync_changed:
+                if not self._aircraftinfos.on_surface:
+                    (self.df_pos_even, self.df_pos_odd) = self._modeSencoder.df_encode_airborne_position(self._aircraftinfos.lat_deg, self._aircraftinfos.lon_deg, self._aircraftinfos.alt_msl_ft, \
+                        self._aircraftinfos.type_code, self._aircraftinfos.surveillance_status, self._aircraftinfos.nicsupb, self._aircraftinfos.timesync)
+                    self._broadcast_thread.replace_message("airborne_position",self.df_pos_even,self.df_pos_odd)
+                    self._broadcast_thread.replace_message("surface_position",[], [])                        
+                else:
+                    (self.df_pos_even, self.df_pos_odd) = self._modeSencoder.df_encode_surface_position(self._aircraftinfos.lat_deg, self._aircraftinfos.lon_deg, self._aircraftinfos.alt_msl_ft, \
+                        self._aircraftinfos.type_code, self._aircraftinfos.surveillance_status, self._aircraftinfos.nicsupb, self._aircraftinfos.timesync)
+                    self._broadcast_thread.replace_message("surface_position",self.df_pos_even,self.df_pos_odd)
+                    self._broadcast_thread.replace_message("airborne_position",[], [])
+
+            if encoder_changed or self._aircraftinfos.speed_changed or self._aircraftinfos.track_angle_changed or self._aircraftinfos.vspeed_changed:
+                self.df_velocity = self._modeSencoder.df_encode_ground_velocity(self._aircraftinfos.speed_kt, self._aircraftinfos.track_angle_deg, self._aircraftinfos.vspeed_ftpmin) 
+                self._broadcast_thread.replace_message("airborne_velocity",self.df_velocity)
+
+            is_first_step = False
+            self.update_aircraftinfos()         # update_aircraftinfos() : abstract method that need to be implemented i nderived classes
+            time.sleep(self.refresh_delay())    # refresh_delay()        : abstract method that need to be implemented i nderived classes
+
+        # upon exit, reset _do_stop flag in case there is a new start
+        self._do_stop = False
+
+    def stop(self):
+        self._do_stop = True
+
+    @abc.abstractmethod
+    def refresh_delay(self):
+        ...
+
+    @abc.abstractmethod
+    def update_aircraftinfos(self):
+        ...