Add proof of concept for Trace(Action)

tracetools_launch/destroy.py

@@ -1,24 +0,0 @@
-
-from typing import List
-from typing import Optional
-from typing import Text
-
-from launch.action import Action
-from launch_context import LaunchContext
-from launch_description_entity import LaunchDescriptionEntity
-
-
-class Destroy(Action):
-    """
-    Action for launch that destroys a tracing session.
-
-    It finalizes and destroys a tracing session that was setup with the Trace action.
-    """
-
-    def __init__(self, session_name: str, **kwargs) -> None:
-        """Constructor."""
-        super().__init__(**kwargs)
-        self.__session_name = session_name
-
-    def execute(self, context: LaunchContext) -> Optional[List[Action]]:
-        pass

tracetools_launch/trace.py

@@ -1,11 +1,14 @@
 
+import os
 from typing import List
 from typing import Optional
 from typing import Text
 
 from launch.action import Action
-from launch_context import LaunchContext
-from launch_description_entity import LaunchDescriptionEntity
+from launch.event import Event
+from launch.event_handlers import OnShutdown
+from launch.launch_context import LaunchContext
+from tracetools_trace.tools import names
 
 
 class Trace(Action):
@@ -15,15 +18,32 @@ class Trace(Action):
     Sets up and enables tracing through a launch file description.
     """
 
-    def __init__(self, *,
+    def __init__(
+        self, *,
         session_name: str,
-        base_path: str,
-        events_ust: List[str],
-        events_kernel: List[str],
+        base_path: str = '/tmp',
+        events_ust: List[str] = names.DEFAULT_EVENTS_ROS,
+        events_kernel: List[str] = names.DEFAULT_EVENTS_KERNEL,
         **kwargs) -> None:
         """Constructor."""
         super().__init__(**kwargs)
+        self.__session_name = session_name
+        self.__path = os.path.join(base_path, session_name)
+        self.__events_ust = events_ust
+        self.__events_kernel = events_kernel
 
     def execute(self, context: LaunchContext) -> Optional[List[Action]]:
+        # TODO make sure this is done as late as possible
+        context.register_event_handler(OnShutdown(
+            on_shutdown=self._destroy,
+        ))
+        # TODO make sure this is done as early as possible
+        self._setup()
+
+    def _setup(self):
         # TODO
-        pass
+        print('setting up tracing!')
+
+    def _destroy(self, event: Event, context: LaunchContext):
+        # TODO
+        print('destroying tracing session!')