[libcamera-devel] [RFC PATCH 10/10] libcamera: framebuffer: Add assertion to detect offset is unfilled

[Laurent Pinchart]

Hi Hiro,

Thank you for the patch.

On Mon, Aug 16, 2021 at 01:31:38PM +0900, Hirokazu Honda wrote:
> The offset variable is introduced to FrameBuffer::Plane. In order to
> detect that the plane is used while the offset is not set, this adds
> the assertion to FrameBuffer::planes(). It should be removed in the
> future.
> 
> Signed-off-by: Hirokazu Honda <hiroh at chromium.org>
> ---
>  include/libcamera/framebuffer.h | 13 +++++++++++--
>  1 file changed, 11 insertions(+), 2 deletions(-)
> 
> diff --git a/include/libcamera/framebuffer.h b/include/libcamera/framebuffer.h
> index 5de3c744..79541557 100644
> --- a/include/libcamera/framebuffer.h
> +++ b/include/libcamera/framebuffer.h
> @@ -7,6 +7,8 @@
>  #ifndef __LIBCAMERA_FRAMEBUFFER_H__
>  #define __LIBCAMERA_FRAMEBUFFER_H__
>  
> +#include <assert.h>
> +#include <limits>
>  #include <stdint.h>
>  #include <vector>
>  
> @@ -41,14 +43,21 @@ class FrameBuffer final : public Extensible
>  
>  public:
>  	struct Plane {
> +		static constexpr unsigned int kInvalidOffset = std::numeric_limits<unsigned int>::max();

Maybe a blank line here ?

This also generates a doxygen warning as kInvalidOffset is not
documented. As it's not meant to be used by anyone else than the code
below, this could be addressed by making the constant private.

>  		FileDescriptor fd;
> -		unsigned int offset;
> +		unsigned int offset = kInvalidOffset;
>  		unsigned int length;
>  	};
>  
>  	FrameBuffer(const std::vector<Plane> &planes, unsigned int cookie = 0);
>  
> -	const std::vector<Plane> &planes() const { return planes_; }
> +	const std::vector<Plane> &planes() const
> +	{
> +		/* \todo remove this assert. */

When do you foresee this being removed ?

> +		for (const auto &plane : planes_)
> +			assert(plane.offset != Plane::kInvalidOffset);
> +		return planes_;
> +	}
>  
>  	Request *request() const;
>  	const FrameMetadata &metadata() const { return metadata_; }

-- 
Regards,

Laurent Pinchart