[igt-dev] [Intel-gfx] [PATCH i-g-t 2/4] intel_gpu_top: Automatically enclose JSON output into brackets

[Kamil Konieczny]

On 2023-01-12 at 17:47:28 +0000, Tvrtko Ursulin wrote:
> From: Tvrtko Ursulin <tvrtko.ursulin at intel.com>
> 
> Parsers need the whole output enclosed into square brackets so every
> period sample becomes an array element.
> 
> So far we have been suggesting this in the man page but we can trivially
> make the tool output that itself.
> 
> Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin at intel.com>
> Cc: Eero Tamminen <eero.t.tamminen at intel.com>

Reviewed-by: Kamil Konieczny <kamil.konieczny at linux.intel.com>

> ---
>  man/intel_gpu_top.rst | 2 +-
>  tools/intel_gpu_top.c | 6 ++++++
>  2 files changed, 7 insertions(+), 1 deletion(-)
> 
> diff --git a/man/intel_gpu_top.rst b/man/intel_gpu_top.rst
> index b0c95446a011..3317e04816b4 100644
> --- a/man/intel_gpu_top.rst
> +++ b/man/intel_gpu_top.rst
> @@ -85,7 +85,7 @@ Filter types: ::
>  JSON OUTPUT
>  ===========
>  
> -To parse the JSON as output by the tool the consumer should wrap its entirety into square brackets ([ ]). This will make each sample point a JSON array element and will avoid "Multiple root elements" JSON validation error.
> +JSON output will be correctly terminated when the tool cleanly exits, otherwise one square bracket needs to be added before parsing.
>  
>  LIMITATIONS
>  ===========
> diff --git a/tools/intel_gpu_top.c b/tools/intel_gpu_top.c
> index 6de8a164fcff..c4d98de4fe31 100644
> --- a/tools/intel_gpu_top.c
> +++ b/tools/intel_gpu_top.c
> @@ -2597,6 +2597,9 @@ int main(int argc, char **argv)
>  	scan_clients(clients, false);
>  	codename = igt_device_get_pretty_name(&card, false);
>  
> +	if (output_mode == JSON)
> +		printf("[\n");
> +
>  	while (!stop_top) {
>  		struct clients *disp_clients;
>  		bool consumed = false;
> @@ -2683,6 +2686,9 @@ int main(int argc, char **argv)
>  			usleep(period_us);
>  	}
>  
> +	if (output_mode == JSON)
> +		printf("]\n");
> +
>  	if (clients)
>  		free_clients(clients);
>  
> -- 
> 2.34.1
>