[PATCH v2] tools lib traceevent: Split pevent_print_event() into specific functionality functions

[Steven Rostedt]

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>
---

v2: This time with the correct event-parse.c path

diff --git a/tools/lib/traceevent/event-parse.c b/tools/lib/traceevent/event-parse.c
index c3bd294a63d1..7cb03e594cdf 100644
--- a/tools/lib/traceevent/event-parse.c
+++ b/tools/lib/traceevent/event-parse.c
@@ -5335,41 +5335,45 @@ 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);
@@ -5377,9 +5381,43 @@ 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) {
@@ -5390,11 +5428,28 @@ 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);
@@ -5404,6 +5459,23 @@ 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/tools/lib/traceevent/event-parse.h b/tools/lib/traceevent/event-parse.h
index 706d9bc24066..9ffde377e89d 100644
--- a/tools/lib/traceevent/event-parse.h
+++ b/tools/lib/traceevent/event-parse.h
@@ -628,6 +628,16 @@ 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);
 
@@ -694,6 +704,9 @@ 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);