[libcamera-devel] [PATCH v2 5/8] android: CameraDevice: Return const shared_ptr& by camera()

[Jacopo Mondi]

Hi Hiro,

On Wed, Mar 24, 2021 at 04:07:54PM +0900, Hirokazu Honda wrote:
> CameraDevice::camera() originally returns shared_ptr. It is
> mandatory to make a copy by calling camera() in this way. There
> is no need of copying if a caller needs the reference of the
> camera like const shared_ptr<Camera> cam = camera(). That is, it
> is a caller that copying is required. This changes the return
> type of camera() to const shared_ptr&, so that we are able to
> reduce one redundant copy in the above case.
>
> Signed-off-by: Hirokazu Honda <hiroh at chromium.org>
> Reviewed-by: Laurent Pinchart <laurent.pinchart at ideasonboard.com>

As I see CameraDevice::camera() being only used in
src/android/camera_hal_manager.cpp:   return cam == camera->camera();

This makes indeed sense. It might not be the greatest API as it's easy
to assume it gets a shared_ptr<> to share ownership.. Probably we
should just return a Camera* ?

This is an improvement anyway, so
Reviewed-by: Jacopo Mondi <jacopo at jmondi.org>

Thanks
   j

> ---
>  src/android/camera_device.h | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/src/android/camera_device.h b/src/android/camera_device.h
> index 555b33e7..14e26b4d 100644
> --- a/src/android/camera_device.h
> +++ b/src/android/camera_device.h
> @@ -43,7 +43,7 @@ public:
>
>  	unsigned int id() const { return id_; }
>  	camera3_device_t *camera3Device() { return &camera3Device_; }
> -	std::shared_ptr<libcamera::Camera> camera() const { return camera_; }
> +	const std::shared_ptr<libcamera::Camera> &camera() const { return camera_; }
>  	libcamera::CameraConfiguration *cameraConfiguration() const
>  	{
>  		return config_.get();
> --
> 2.31.0.291.g576ba9dcdaf-goog
> _______________________________________________
> libcamera-devel mailing list
> libcamera-devel at lists.libcamera.org
> https://lists.libcamera.org/listinfo/libcamera-devel