[libcamera-devel] [PATCH v4 1/7] delayed_controls: Template the ControlRingBuffer class

[Kieran Bingham]

Hi Naush,

Quoting Naushir Patuck via libcamera-devel (2022-10-19 10:01:01)
> Convert ControlRingBuffer to a templated class to allow arbitrary ring buffer
> array types to be defined. Rename ControlRingBuffer to RingBuffer to indicate
> this.
> 
> Signed-off-by: Naushir Patuck <naush at raspberrypi.com>
> Reviewed-by: David Plowman <david.plowman at raspberrypi.com>
> Tested-by: David Plowman <david.plowman at raspberrypi.com>

I know Laurent has been investigating 'generic' ring-buffer
implementations, but that sounded like it grew into a rabbit hole, and
this is quite localised.

I can see it's going to help later in the series, and it doesn't impact
anything else here so:


Reviewed-by: Kieran Bingham <kieran.bingham at ideasonboard.com>


> ---
>  include/libcamera/internal/delayed_controls.h | 13 +++++++------
>  1 file changed, 7 insertions(+), 6 deletions(-)
> 
> diff --git a/include/libcamera/internal/delayed_controls.h b/include/libcamera/internal/delayed_controls.h
> index aef37077103c..de8026e3e4f0 100644
> --- a/include/libcamera/internal/delayed_controls.h
> +++ b/include/libcamera/internal/delayed_controls.h
> @@ -53,17 +53,18 @@ private:
>  
>         /* \todo Make the listSize configurable at instance creation time. */
>         static constexpr int listSize = 16;
> -       class ControlRingBuffer : public std::array<Info, listSize>
> +       template<typename T>
> +       class RingBuffer : public std::array<T, listSize>
>         {
>         public:
> -               Info &operator[](unsigned int index)
> +               T &operator[](unsigned int index)
>                 {
> -                       return std::array<Info, listSize>::operator[](index % listSize);
> +                       return std::array<T, listSize>::operator[](index % listSize);
>                 }
>  
> -               const Info &operator[](unsigned int index) const
> +               const T &operator[](unsigned int index) const
>                 {
> -                       return std::array<Info, listSize>::operator[](index % listSize);
> +                       return std::array<T, listSize>::operator[](index % listSize);
>                 }
>         };
>  
> @@ -75,7 +76,7 @@ private:
>         uint32_t queueCount_;
>         uint32_t writeCount_;
>         /* \todo Evaluate if we should index on ControlId * or unsigned int */
> -       std::unordered_map<const ControlId *, ControlRingBuffer> values_;
> +       std::unordered_map<const ControlId *, RingBuffer<Info>> values_;
>  };
>  
>  } /* namespace libcamera */
> -- 
> 2.25.1
>