Daniel P Berrange writes:
> Currently methods which want to iterate over trace events,
> do so using the trace_event_count() and trace_event_id()
> methods. This leaks the concept of a single ID enum to
> the callers. There is an alternative trace_event_pattern()
> method which can be used in an iteration context, but its
> design is stateless, so is not easy to expand it in the
> future.
> This defines a formal iterator API will provide an future
> proof way of iterating over events.
an -> a
future proof -> future-proof
> The iterator is also able to apply a pattern match filter
> to events, further removing the need for the pattern
> Signed-off-by: Daniel P. Berrange <berra...@redhat.com>
As for patch contents:
Reviewed-by: Lluís Vilanova <vilan...@ac.upc.edu>
> ---
> trace/control.c | 21 +++++++++++++++++++++
> trace/control.h | 27 +++++++++++++++++++++++++++
> 2 files changed, 48 insertions(+)
> diff --git a/trace/control.c b/trace/control.c
> index 05d85ac..1a96049 100644
> --- a/trace/control.c
> +++ b/trace/control.c
> @@ -125,6 +125,27 @@ TraceEvent *trace_event_pattern(const char *pat,
> TraceEvent *ev)
> return NULL;
> }
> +void trace_event_iter_init(TraceEventIter *iter, const char *pattern)
> +{
> + iter->event = 0;
> + iter->pattern = pattern;
> +}
> +
> +TraceEvent *trace_event_iter_next(TraceEventIter *iter)
> +{
> + while (iter->event < TRACE_EVENT_COUNT) {
> + TraceEvent *ev = &(trace_events[iter->event]);
> + iter->event++;
> + if (!iter->pattern ||
> + pattern_glob(iter->pattern,
> + trace_event_get_name(ev))) {
> + return ev;
> + }
> + }
> +
> + return NULL;
> +}
> +
> void trace_list_events(void)
> {
> int i;
> diff --git a/trace/control.h b/trace/control.h
> index 27a16fc..c71b405 100644
> --- a/trace/control.h
> +++ b/trace/control.h
> @@ -13,6 +13,10 @@
> #include "qemu-common.h"
> #include "trace/generated-events.h"
> +typedef struct TraceEventIter {
> + size_t event;
> + const char *pattern;
> +} TraceEventIter;
> /**
> * TraceEventID:
> @@ -25,6 +29,29 @@
> */
> enum TraceEventID;
> +
> +/**
> + * trace_event_iter_init:
> + * @iter: the event iterator struct
> + * @pattern: optional pattern to filter events on name
> + *
> + * Initialize the event iterator struct @iter,
> + * optionally using @pattern to filter out events
> + * with non-matching names.
> + */
> +void trace_event_iter_init(TraceEventIter *iter, const char *pattern);
> +
> +/**
> + * trace_event_iter_next:
> + * @iter: the event iterator struct
> + *
> + * Get the next event, if any. When this returns NULL,
> + * the iterator should no longer be used.
> + *
> + * Returns: the next event, or NULL if no more events exist
> + */
> +TraceEvent *trace_event_iter_next(TraceEventIter *iter);
> +
> /**
> * trace_event_id:
> * @id: Event identifier.
> --
> 2.7.4
