Re: [PATCH] tools lib traceevent: Split pevent_print_event() into specific functionality functions
From: Arnaldo Carvalho de Melo
Date: Thu Feb 25 2016 - 15:14:24 EST
Em Thu, Feb 25, 2016 at 12:20:33PM -0500, Steven Rostedt escreveu:
> Currently there's a single function that is used to display a record's
> data in human readable format. That's pevent_print_event().
> Unfortunately, this gives little room for adding other output within
> the line without updating that function call.
>
> I've decided to split that function into 3 parts.
>
> pevent_print_event_task() which prints the task comm, pid and the CPU
> pevent_print_event_time() which outputs the record's timestamp
> pevent_print_event_data() which outputs the rest of the event data.
>
> pevent_print_event() now simply calls these three functions.
>
> To save time from doing the search for event from the record's type, I
> created a new helper function called pevent_find_event_by_record(),
> which returns the record's event, and this event has to be passed to
> the above functions.
>
> Signed-off-by: Steven Rostedt <rostedt@xxxxxxxxxxx>
> ---
> diff --git a/event-parse.c b/event-parse.c
> index 18e93e430b8b..559d77381a60 100644
> --- a/event-parse.c
> +++ b/event-parse.c
Isn't this on tools/lib/traceevent?
- Arnaldo
> @@ -5364,41 +5364,45 @@ static bool is_timestamp_in_us(char *trace_clock, bool use_trace_clock)
> return false;
> }
>
> -void pevent_print_event(struct pevent *pevent, struct trace_seq *s,
> - struct pevent_record *record, bool use_trace_clock)
> +/**
> + * pevent_find_event_by_record - return the event from a given record
> + * @pevent: a handle to the pevent
> + * @record: The record to get the event from
> + *
> + * Returns the associated event for a given record, or NULL if non is
> + * is found.
> + */
> +struct event_format *
> +pevent_find_event_by_record(struct pevent *pevent, struct pevent_record *record)
> {
> - static const char *spaces = " "; /* 20 spaces */
> - struct event_format *event;
> - unsigned long secs;
> - unsigned long usecs;
> - unsigned long nsecs;
> - const char *comm;
> - void *data = record->data;
> int type;
> - int pid;
> - int len;
> - int p;
> - bool use_usec_format;
> -
> - use_usec_format = is_timestamp_in_us(pevent->trace_clock,
> - use_trace_clock);
> - if (use_usec_format) {
> - secs = record->ts / NSECS_PER_SEC;
> - nsecs = record->ts - secs * NSECS_PER_SEC;
> - }
>
> if (record->size < 0) {
> do_warning("ug! negative record size %d", record->size);
> - return;
> + return NULL;
> }
>
> - type = trace_parse_common_type(pevent, data);
> + type = trace_parse_common_type(pevent, record->data);
>
> - event = pevent_find_event(pevent, type);
> - if (!event) {
> - do_warning("ug! no event found for type %d", type);
> - return;
> - }
> + return pevent_find_event(pevent, type);
> +}
> +
> +/**
> + * pevent_print_event_task - Write the event task comm, pid and CPU
> + * @pevent: a handle to the pevent
> + * @s: the trace_seq to write to
> + * @event: the handle to the record's event
> + * @record: The record to get the event from
> + *
> + * Writes the tasks comm, pid and CPU to @s.
> + */
> +void pevent_print_event_task(struct pevent *pevent, struct trace_seq *s,
> + struct event_format *event,
> + struct pevent_record *record)
> +{
> + void *data = record->data;
> + const char *comm;
> + int pid;
>
> pid = parse_common_pid(pevent, data);
> comm = find_cmdline(pevent, pid);
> @@ -5406,9 +5410,43 @@ void pevent_print_event(struct pevent *pevent, struct trace_seq *s,
> if (pevent->latency_format) {
> trace_seq_printf(s, "%8.8s-%-5d %3d",
> comm, pid, record->cpu);
> - pevent_data_lat_fmt(pevent, s, record);
> } else
> trace_seq_printf(s, "%16s-%-5d [%03d]", comm, pid, record->cpu);
> +}
> +
> +/**
> + * pevent_print_event_time - Write the event timestamp
> + * @pevent: a handle to the pevent
> + * @s: the trace_seq to write to
> + * @event: the handle to the record's event
> + * @record: The record to get the event from
> + * @use_trace_clock: Set to parse according to the @pevent->trace_clock
> + *
> + * Writes the timestamp of the record into @s.
> + */
> +void pevent_print_event_time(struct pevent *pevent, struct trace_seq *s,
> + struct event_format *event,
> + struct pevent_record *record,
> + bool use_trace_clock)
> +{
> + unsigned long secs;
> + unsigned long usecs;
> + unsigned long nsecs;
> + int p;
> + bool use_usec_format;
> +
> + use_usec_format = is_timestamp_in_us(pevent->trace_clock,
> + use_trace_clock);
> + if (use_usec_format) {
> + secs = record->ts / NSECS_PER_SEC;
> + nsecs = record->ts - secs * NSECS_PER_SEC;
> + }
> +
> + if (pevent->latency_format) {
> + trace_seq_printf(s, " %3d", record->cpu);
> + pevent_data_lat_fmt(pevent, s, record);
> + } else
> + trace_seq_printf(s, " [%03d]", record->cpu);
>
> if (use_usec_format) {
> if (pevent->flags & PEVENT_NSEC_OUTPUT) {
> @@ -5424,11 +5462,28 @@ void pevent_print_event(struct pevent *pevent, struct trace_seq *s,
> p = 6;
> }
>
> - trace_seq_printf(s, " %5lu.%0*lu: %s: ",
> - secs, p, usecs, event->name);
> + trace_seq_printf(s, " %5lu.%0*lu:", secs, p, usecs);
> } else
> - trace_seq_printf(s, " %12llu: %s: ",
> - record->ts, event->name);
> + trace_seq_printf(s, " %12llu:", record->ts);
> +}
> +
> +/**
> + * pevent_print_event_data - Write the event data section
> + * @pevent: a handle to the pevent
> + * @s: the trace_seq to write to
> + * @event: the handle to the record's event
> + * @record: The record to get the event from
> + *
> + * Writes the parsing of the record's data to @s.
> + */
> +void pevent_print_event_data(struct pevent *pevent, struct trace_seq *s,
> + struct event_format *event,
> + struct pevent_record *record)
> +{
> + static const char *spaces = " "; /* 20 spaces */
> + int len;
> +
> + trace_seq_printf(s, " %s: ", event->name);
>
> /* Space out the event names evenly. */
> len = strlen(event->name);
> @@ -5438,6 +5493,23 @@ void pevent_print_event(struct pevent *pevent, struct trace_seq *s,
> pevent_event_info(s, event, record);
> }
>
> +void pevent_print_event(struct pevent *pevent, struct trace_seq *s,
> + struct pevent_record *record, bool use_trace_clock)
> +{
> + struct event_format *event;
> +
> + event = pevent_find_event_by_record(pevent, record);
> + if (!event) {
> + do_warning("ug! no event found for type %d",
> + trace_parse_common_type(pevent, record->data));
> + return;
> + }
> +
> + pevent_print_event_task(pevent, s, event, record);
> + pevent_print_event_time(pevent, s, event, record, use_trace_clock);
> + pevent_print_event_data(pevent, s, event, record);
> +}
> +
> static int events_id_cmp(const void *a, const void *b)
> {
> struct event_format * const * ea = a;
> diff --git a/event-parse.h b/event-parse.h
> index ea653580c197..a3fd9b28a5eb 100644
> --- a/event-parse.h
> +++ b/event-parse.h
> @@ -632,6 +632,16 @@ int pevent_register_print_string(struct pevent *pevent, const char *fmt,
> unsigned long long addr);
> int pevent_pid_is_registered(struct pevent *pevent, int pid);
>
> +void pevent_print_event_task(struct pevent *pevent, struct trace_seq *s,
> + struct event_format *event,
> + struct pevent_record *record);
> +void pevent_print_event_time(struct pevent *pevent, struct trace_seq *s,
> + struct event_format *event,
> + struct pevent_record *record,
> + bool use_trace_clock);
> +void pevent_print_event_data(struct pevent *pevent, struct trace_seq *s,
> + struct event_format *event,
> + struct pevent_record *record);
> void pevent_print_event(struct pevent *pevent, struct trace_seq *s,
> struct pevent_record *record, bool use_trace_clock);
>
> @@ -698,6 +708,9 @@ struct event_format *pevent_find_event(struct pevent *pevent, int id);
> struct event_format *
> pevent_find_event_by_name(struct pevent *pevent, const char *sys, const char *name);
>
> +struct event_format *
> +pevent_find_event_by_record(struct pevent *pevent, struct pevent_record *record);
> +
> void pevent_data_lat_fmt(struct pevent *pevent,
> struct trace_seq *s, struct pevent_record *record);
> int pevent_data_type(struct pevent *pevent, struct pevent_record *rec);