[PATCH weston 4/5] window: merge struct surface_data into shm_surface_data

[Kristian Høgsberg]

On Mon, Nov 19, 2012 at 03:32:50PM +0200, Pekka Paalanen wrote:
> Struct surface_data was not really useful, and it definitely was not
> used with EGL-based windows.
> 
> This also fixes a semantic mistake, where struct shm_surface_data was
> put into cairo_surface_t private, but got out as struct surface_data
> instead. Due to struct layout, however, this did not cause a real bug.

This wasn't a mistake - it's pretty common to put a struct into
another struct as the first member and then just cast between the
pointers.  Using container_of is more general and lets you put the
embedded struct anywhere in the containing struct, but consistently
placing the embedded struct first is a valid and common pattern.

Kristian

> Signed-off-by: Pekka Paalanen <ppaalanen at gmail.com>
> ---
>  clients/window.c |   25 +++++++++++--------------
>  1 files changed, 11 insertions(+), 14 deletions(-)
> 
> diff --git a/clients/window.c b/clients/window.c
> index 16dc801..18bacfc 100644
> --- a/clients/window.c
> +++ b/clients/window.c
> @@ -347,9 +347,6 @@ enum window_location {
>  };
>  
>  static const cairo_user_data_key_t surface_data_key;
> -struct surface_data {
> -	struct wl_buffer *buffer;
> -};
>  
>  #ifdef HAVE_CAIRO_EGL
>  
> @@ -414,22 +411,22 @@ display_create_egl_window_surface(struct display *display,
>  
>  #endif
>  
> +struct shm_surface_data {
> +	struct wl_buffer *buffer;
> +	struct shm_pool *pool;
> +};
> +
>  struct wl_buffer *
>  display_get_buffer_for_surface(struct display *display,
>  			       cairo_surface_t *surface)
>  {
> -	struct surface_data *data;
> +	struct shm_surface_data *data;
>  
>  	data = cairo_surface_get_user_data (surface, &surface_data_key);
>  
>  	return data->buffer;
>  }
>  
> -struct shm_surface_data {
> -	struct surface_data data;
> -	struct shm_pool *pool;
> -};
> -
>  static void
>  shm_pool_destroy(struct shm_pool *pool);
>  
> @@ -438,7 +435,7 @@ shm_surface_data_destroy(void *p)
>  {
>  	struct shm_surface_data *data = p;
>  
> -	wl_buffer_destroy(data->data.buffer);
> +	wl_buffer_destroy(data->buffer);
>  	if (data->pool)
>  		shm_pool_destroy(data->pool);
>  
> @@ -570,10 +567,10 @@ display_create_shm_surface_from_pool(struct display *display,
>  	else
>  		format = WL_SHM_FORMAT_ARGB8888;
>  
> -	data->data.buffer = wl_shm_pool_create_buffer(pool->pool, offset,
> -						      rectangle->width,
> -						      rectangle->height,
> -						      stride, format);
> +	data->buffer = wl_shm_pool_create_buffer(pool->pool, offset,
> +						 rectangle->width,
> +						 rectangle->height,
> +						 stride, format);
>  
>  	return surface;
>  }
> -- 
> 1.7.8.6
>