Note, the subject should not have a period.
On Tue, 30 Nov 2021 07:00:57 +0200
"Tzvetomir Stoyanov (VMware)" <tz.stoyanov@xxxxxxxxx> wrote:
> There is no API for applying a filter string on event. Existing APIs
"on an event."
> only constructs and verifies the filter string. Even though the actual
"only construct and verify"
> applying is just writing into the event's filter file, it is good to
> have a dedicated API for that:
[ add empty line here ]
> tracefs_event_apply_filter()
>
> Signed-off-by: Tzvetomir Stoyanov (VMware) <tz.stoyanov@xxxxxxxxx>
> ---
> Documentation/libtracefs-filter.txt | 11 ++++++++++-
> include/tracefs.h | 3 +++
> src/tracefs-filter.c | 19 +++++++++++++++++++
> 3 files changed, 32 insertions(+), 1 deletion(-)
>
> diff --git a/Documentation/libtracefs-filter.txt b/Documentation/libtracefs-filter.txt
> index 7e167bc..7532c96 100644
> --- a/Documentation/libtracefs-filter.txt
> +++ b/Documentation/libtracefs-filter.txt
> @@ -3,7 +3,8 @@ libtracefs(3)
>
> NAME
> ----
> -tracefs_event_append_filter, tracefs_event_verify_filter - Add and verify event filters
> +tracefs_event_append_filter, tracefs_event_verify_filter tracefs_event_apply_filter -
Missing comma (and you also need to rebase with the updates).
> +Add, verify and apply event filters
>
> SYNOPSIS
> --------
> @@ -15,6 +16,7 @@ int tracefs_event_append_filter(struct tep_event pass:[*]event, char pass:[**] f
> struct tracefs_filter type, const char pass:[*]field,
> enum tracefs_synth_compare compare, const char pass:[*]val);
> int tracefs_event_verify_filter(struct tep_event pass:[*]event, const char pass:[*]filter, char pass:[**]err);
I renamed the above, because it doesn't really affect the event.
> +int tracefs_event_apply_filter(struct tracefs_instance pass:[*]instance, struct tep_event pass:[*]event, const char pass:[*]filter);
But you can keep this name, as it makes sense to call this
"tracefs_event_.."
>
> --
>
> @@ -66,6 +68,8 @@ error in the syntax, and _err_ is not NULL, then it will be allocated with an
> error message stating what was found wrong with the filter. _err_ must be freed
> with *free*().
>
> +*tracefs_event_apply_filter*() applies given _filter_ string on _event_ in given _instance_.
> +
> RETURN VALUE
> ------------
> *tracefs_event_append_filter*() returns 0 on success and -1 on error.
> @@ -75,6 +79,8 @@ is an error, and _errno_ is not *ENOMEM*, then _err_ is allocated and will
> contain a string describing what was found wrong with _filter_. _err_ must be
> freed with *free*().
>
> +*tracefs_event_apply_filter*() returns 0 on success and -1 on error.
> +
> EXAMPLE
> -------
> [source,c]
> @@ -269,6 +275,9 @@ int main (int argc, char **argv)
> }
> }
>
> + if (tracefs_event_apply_filter(NULL, event, new_filter))
> + fprintf(stderr, "Failed to apply filter on event");
> +
> tep_free(tep);
>
> printf("Created new filter: '%s'\n", new_filter);
> diff --git a/include/tracefs.h b/include/tracefs.h
> index fbd7d31..8ac9694 100644
> --- a/include/tracefs.h
> +++ b/include/tracefs.h
> @@ -475,6 +475,9 @@ int tracefs_event_append_filter(struct tep_event *event, char **filter,
> const char *val);
> int tracefs_event_verify_filter(struct tep_event *event, const char *filter,
> char **err);
> +int tracefs_event_apply_filter(struct tracefs_instance *instance,
> + struct tep_event *event, const char *filter);
> +
>
> #define TRACEFS_TIMESTAMP "common_timestamp"
> #define TRACEFS_TIMESTAMP_USECS "common_timestamp.usecs"
> diff --git a/src/tracefs-filter.c b/src/tracefs-filter.c
> index def8f68..43683d0 100644
> --- a/src/tracefs-filter.c
> +++ b/src/tracefs-filter.c
> @@ -745,3 +745,22 @@ int tracefs_event_verify_filter(struct tep_event *event, const char *filter,
> free(str);
> return 0;
> }
> +
> +/**
> + * tracefs_event_apply_filter - apply given filter on event in given instance
> + * @instance: The instance in which the filter will be applied (NULL for toplevel).
> + * @event: The event to apply the filter on.
> + * @filter: The filter to apply.
> + *
> + * Apply the @filter to given @event in givem @instance. The @filter string
> + * should be created with tracefs_event_append_filter().
The name of the function has been renamed.
> + *
> + * Returns 0 on succes and -1 on error.
> + */
> +int tracefs_event_apply_filter(struct tracefs_instance *instance,
> + struct tep_event *event, const char *filter)
> +{
> + return tracefs_event_file_append(instance, event->system, event->name,
> + "filter", filter);
I think we want this to be tracefs_event_file_write(), as it should replace
the filter, not add on to it.
> +}
> +
Note, I moved the old deprecated names at the end of the file. Make sure
they stay at the end. In other words, this goes before them.
-- Steve
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