[libcamera-devel] [PATCH 23/31] libcamera: byte_stream_buffer: Add Span<> support

[Kieran Bingham]

On 29/02/2020 16:42, Laurent Pinchart wrote:
> From: Jacopo Mondi <jacopo at jmondi.org>
> 
> Add support to read and write a Span<> from and to the ByteStreamBuffer

s/from and to/to and from/

(Yes, I know that matches the 'order' of read and write, but we would
not really say "from and to" in English)

> class.
> 
> Signed-off-by: Jacopo Mondi <jacopo at jmondi.org>
> Signed-off-by: Laurent Pinchart <laurent.pinchart at ideasonboard.com>

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



> ---
>  src/libcamera/byte_stream_buffer.cpp       | 18 ++++++++++++++++++
>  src/libcamera/include/byte_stream_buffer.h | 17 +++++++++++++++++
>  2 files changed, 35 insertions(+)
> 
> diff --git a/src/libcamera/byte_stream_buffer.cpp b/src/libcamera/byte_stream_buffer.cpp
> index cd1d8a36d464..40380bf0434a 100644
> --- a/src/libcamera/byte_stream_buffer.cpp
> +++ b/src/libcamera/byte_stream_buffer.cpp
> @@ -232,6 +232,15 @@ int ByteStreamBuffer::skip(size_t size)
>   * \retval -ENOSPC no more space is available in the managed memory buffer
>   */
>  
> +/**
> + * \fn template<typename T> int ByteStreamBuffer::read(const Span<T> &data)
> + * \brief Read data from the managed memory buffer into span \a data

s/span/Span/ ?

> + * \param[out] data Span representing the destination memory
> + * \return 0 on success, a negative error code otherwise
> + * \retval -EACCES attempting to read from a write buffer
> + * \retval -ENOSPC no more space is available in the managed memory buffer
> + */
> +
>  /**
>   * \fn template<typename T> int ByteStreamBuffer::write(const T *t)
>   * \brief Write \a t to the managed memory buffer
> @@ -241,6 +250,15 @@ int ByteStreamBuffer::skip(size_t size)
>   * \retval -ENOSPC no more space is available in the managed memory buffer
>   */
>  
> +/**
> + * \fn template<typename T> int ByteStreamBuffer::write(const Span<T> &data)
> + * \brief Write \a data to the managed memory buffer
> + * \param[in] data The data to write to memory
> + * \return 0 on success, a negative error code otherwise
> + * \retval -EACCES attempting to write to a read buffer
> + * \retval -ENOSPC no more space is available in the managed memory buffer
> + */
> +
>  int ByteStreamBuffer::read(uint8_t *data, size_t size)
>  {
>  	if (!read_)
> diff --git a/src/libcamera/include/byte_stream_buffer.h b/src/libcamera/include/byte_stream_buffer.h
> index b5274c62b85e..17cb0146061e 100644
> --- a/src/libcamera/include/byte_stream_buffer.h
> +++ b/src/libcamera/include/byte_stream_buffer.h
> @@ -10,6 +10,8 @@
>  #include <stddef.h>
>  #include <stdint.h>
>  
> +#include <libcamera/span.h>
> +
>  namespace libcamera {
>  
>  class ByteStreamBuffer
> @@ -33,12 +35,27 @@ public:
>  	{
>  		return read(reinterpret_cast<uint8_t *>(t), sizeof(*t));
>  	}
> +
> +	template<typename T>
> +	int read(const Span<T> &data)
> +	{
> +		return read(reinterpret_cast<uint8_t *>(data.data()),
> +			    data.size_bytes());
> +	}
> +
>  	template<typename T>
>  	int write(const T *t)
>  	{
>  		return write(reinterpret_cast<const uint8_t *>(t), sizeof(*t));
>  	}
>  
> +	template<typename T>
> +	int write(const Span<T> &data)
> +	{
> +		return write(reinterpret_cast<const uint8_t *>(data.data()),
> +			     data.size_bytes());
> +	}
> +
>  private:
>  	ByteStreamBuffer(const ByteStreamBuffer &other) = delete;
>  	ByteStreamBuffer &operator=(const ByteStreamBuffer &other) = delete;
> 

-- 
Regards
--
Kieran