Re: [PATCH] libtraceeval: Use name for type look up for traceeval_stat

[Ross Zwisler <zwisler@google.com>]

On Tue, Oct 03, 2023 at 06:12:37PM -0400, Steven Rostedt wrote:
> From: "Steven Rostedt (Google)" <rostedt@goodmis.org>
> 
> The functions that retrieve the traceeval_stat currently requires passing
> in the struct traceeval_type. But this is fragile, as it may not be set up
> properly. It was originally done that way as a "fast" way to look up
> stats, but in reality it will likely just cause more issues with wrong
> types passed in. That decision was based more on defining policy which the
> library should not do.
> 
> Instead, just pass in the string name of the value type to find and
> retrieve the traceeval_data value from the traceeval that way.
> 
> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
> ---
>  include/traceeval.h |  4 ++--
>  src/histograms.c    | 39 ++++++++++++++++++++++++++++++---------
>  2 files changed, 32 insertions(+), 11 deletions(-)
> 
> diff --git a/include/traceeval.h b/include/traceeval.h
> index 48c28dfc2f99..32996ba17e5f 100644
> --- a/include/traceeval.h
> +++ b/include/traceeval.h
> @@ -219,7 +219,7 @@ size_t traceeval_count(struct traceeval *teval);
>  struct traceeval_stat *traceeval_stat_size(struct traceeval *teval,
>  					   const struct traceeval_data *keys,
>  					   size_t nr_keys,
> -					   struct traceeval_type *type);
> +					   const char *val_name);

Probably need to also s/type/val_name/g for the traceeval_stat() macro so they
stay in sync, and need to update the calls to traceeval_iterator_stat() and
traceeval_stat() in samples/task-eval.c so they continue to work.