Re: [igt-dev] [PATCH i-g-t 2/6] igt_core: Split too long log lines when sending to runner with comms

[Kamil Konieczny <kamil.konieczny@linux.intel.com>]

Hi Petri,

On 2022-11-07 at 14:01:47 +0200, Petri Latvala wrote:
> Especially with file dumps a single log packet could exceed the max
> size of a UNIX datagram. Split too long log chunks instead.

imho this is needed when you check packet size in other patch,
it's network layer decision to split or not packets, so on local
machine no split happens (well, I may be wrong here as I do not
know much about network communication). The other way around
would be to collect packet up to sended size.

> 
> Signed-off-by: Petri Latvala <petri.latvala@intel.com>
> Cc: Arkadiusz Hiler <arek@hiler.eu>
> Cc: Kamil Konieczny <kamil.konieczny@linux.intel.com>
> ---
>  lib/igt_core.c | 19 ++++++++++++++++++-
>  1 file changed, 18 insertions(+), 1 deletion(-)
> 
> diff --git a/lib/igt_core.c b/lib/igt_core.c
> index 3941c528..d4bef161 100644
> --- a/lib/igt_core.c
> +++ b/lib/igt_core.c
> @@ -457,6 +457,23 @@ static void _igt_log_buffer_reset(void)
>  	pthread_mutex_unlock(&log_buffer_mutex);
>  }
>  
> +static void _log_to_runner_split(int stream, const char *str)
> +{
> +	size_t limit = 4096;
> +	char *buf;
> +
> +	if (strlen(str) > limit) {
> +		buf = calloc(limit + 1, 1);
> +		strncpy(buf, str, limit);
> +		send_to_runner(runnerpacket_log(stream, buf));
> +		free(buf);
> +
> +		_log_to_runner_split(stream, str + limit);
> +	} else {
> +		send_to_runner(runnerpacket_log(stream, str));
> +	}
> +}
> +

There are many places which calls send_to_runner, maybe it would
be better to split it there ?
Or use _log_to_runner instead of send_to_runner ?
Btw a while loop would be better than recursive call.

Kamil

>  __attribute__((format(printf, 2, 3)))
>  static void _log_line_fprintf(FILE* stream, const char *format, ...)
>  {
> @@ -467,7 +484,7 @@ static void _log_line_fprintf(FILE* stream, const char *format, ...)
>  
>  	if (runner_connected()) {
>  		vasprintf(&str, format, ap);
> -		send_to_runner(runnerpacket_log(fileno(stream), str));
> +		_log_to_runner_split(fileno(stream), str);
>  		free(str);
>  	} else {
>  		vfprintf(stream, format, ap);
> -- 
> 2.30.2
>