[Component] Add pause and resume events methods

For future use add ability to handle pause and resume events

Co-authored-by: Calum Lind <calumlind+deluge@gmail.com>

deluge/component.py

@@ -64,6 +64,11 @@ class Component:
                    paused by instructing the :class:`ComponentRegistry` to pause
                    this Component.
 
+        **pause()** - This method is called when the component is being paused.
+
+        **resume()** - This method is called when the component resumes from a Paused
+                    state.
+
         **shutdown()** - This method is called when the client is exiting.  If the
                      Component is in a "Started" state when this is called, a
                      call to stop() will be issued prior to shutdown().
@@ -175,13 +180,12 @@ class Component:
     def _component_pause(self):
         def on_pause(result):
             self._component_state = 'Paused'
+            if self._component_timer and self._component_timer.running:
+                self._component_timer.stop()
 
         if self._component_state == 'Started':
-            if self._component_timer and self._component_timer.running:
-                d = maybeDeferred(self._component_timer.stop)
-                d.addCallback(on_pause)
-            else:
-                d = succeed(None)
+            d = maybeDeferred(self.pause)
+            d.addCallback(on_pause)
         elif self._component_state == 'Paused':
             d = succeed(None)
         else:
@@ -198,9 +202,10 @@ class Component:
     def _component_resume(self):
         def on_resume(result):
             self._component_state = 'Started'
+            self._component_start_timer()
 
         if self._component_state == 'Paused':
-            d = maybeDeferred(self._component_start_timer)
+            d = maybeDeferred(self.resume)
             d.addCallback(on_resume)
         else:
             d = fail(
@@ -236,6 +241,12 @@ class Component:
     def shutdown(self):
         pass
 
+    def pause(self):
+        pass
+
+    def resume(self):
+        pass
+
 
 class ComponentRegistry:
     """The ComponentRegistry holds a list of currently registered :class:`Component` objects.

deluge/tests/test_component.py

@@ -17,7 +17,7 @@ import deluge.component as component
 class ComponentTester(component.Component):
     def __init__(self, name, depend=None):
         super().__init__(name, depend=depend)
-        event_methods = ('start', 'update', 'stop', 'shutdown')
+        event_methods = ('start', 'update', 'pause', 'resume', 'stop', 'shutdown')
         for event_method in event_methods:
             setattr(self, event_method, Mock())
 
@@ -145,9 +145,27 @@ class TestComponent:
         await component.pause(['test_pause'])
 
         assert c._component_state == 'Paused'
+        assert c.pause.call_count == 1
         assert c.update.call_count != init_update_count
         assert not c._component_timer.running
 
+    async def test_resume(self):
+        c = ComponentTester('test_resume')
+
+        await component.start(['test_resume'])
+
+        assert c._component_state == 'Started'
+
+        await component.pause(['test_resume'])
+
+        assert c._component_state == 'Paused'
+
+        await component.resume(['test_resume'])
+
+        assert c._component_state == 'Started'
+        assert c.resume.call_count == 1
+        assert c._component_timer.running
+
     async def test_component_start_error(self):
         ComponentTester('test_start_error')
         await component.start(['test_start_error'])