[libcamera-devel] [PATCH v3 12/17] py: cam.py: Use new events support

[Jacopo Mondi]

Hi Tomi

On Fri, Jul 01, 2022 at 11:45:16AM +0300, Tomi Valkeinen wrote:
> Convert cam.py to use the new event dispatching. In addition to handling
> the request-completed event, handle also disconnect, camera-added and
> camera-removed events (which only do a simple print).
>
> Signed-off-by: Tomi Valkeinen <tomi.valkeinen at ideasonboard.com>
> ---
>  src/py/cam/cam.py | 31 +++++++++++++++++++++++++------
>  1 file changed, 25 insertions(+), 6 deletions(-)
>
> diff --git a/src/py/cam/cam.py b/src/py/cam/cam.py
> index 6b6b678b..f19bad57 100755
> --- a/src/py/cam/cam.py
> +++ b/src/py/cam/cam.py
> @@ -230,11 +230,20 @@ class CaptureState:
>      # Called from renderer when there is a libcamera event
>      def event_handler(self):
>          try:
> -            reqs = self.cm.get_ready_requests()
> -
> -            for req in reqs:
> -                ctx = next(ctx for ctx in self.contexts if ctx.idx == req.cookie)
> -                self.__request_handler(ctx, req)
> +            evs = self.cm.get_events()
> +            for ev in evs:
> +                type = ev.type
> +
> +                if type == libcam.Event.Type.Undefined:
> +                    raise RuntimeError("Bad event type")
> +                elif type == libcam.Event.Type.CameraAdded:
> +                    print('Camera added:', ev.camera)
> +                elif type == libcam.Event.Type.CameraRemoved:
> +                    print('Camera added:', ev.camera)

s/added/removed/

> +                elif type == libcam.Event.Type.Disconnect:
> +                    self.__disconnect_handler(ev.camera)
> +                elif type == libcam.Event.Type.RequestCompleted:
> +                    self.__request_handler(ev.camera, ev.request)
>
>              running = any(ctx.reqs_completed < ctx.opt_capture for ctx in self.contexts)
>              return running
> @@ -242,7 +251,9 @@ class CaptureState:
>              traceback.print_exc()
>              return False
>
> -    def __request_handler(self, ctx, req):
> +    def __request_handler(self, cam, req):
> +        ctx = next(ctx for ctx in self.contexts if ctx.camera == cam)
> +
>          if req.status != libcam.Request.Status.Complete:
>              raise Exception('{}: Request failed: {}'.format(ctx.id, req.status))
>
> @@ -297,6 +308,9 @@ class CaptureState:
>              ctx.camera.queue_request(req)
>              ctx.reqs_queued += 1
>
> +    def __disconnect_handler(self, cam):
> +        print(f'Camera {cam} disconnected')
> +

Why this has a separate handler while the other ones that simply print
a message do not ?

Nit apart:
Reviewed-by: Jacopo Mondi <jacopo at jmondi.org>

Thanks
  j

>      def __capture_init(self):
>          for ctx in self.contexts:
>              ctx.acquire()
> @@ -447,6 +461,11 @@ def main():
>
>          state.do_cmd_capture()
>
> +        # This is not strictly needed, but it helps to do a proper cleanup as we
> +        # drop any unhandled events, and so makes it easier to use memory leak
> +        # detectors.
> +        cm.get_events()
> +
>      return 0
>
>
> --
> 2.34.1
>