perf session: Add process callback to reader object

Adding callback function to reader object so callers can process data in
different ways.
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Alexey Budankov <alexey.budankov@linux.intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/r/20190308134745.5057-7-jolsa@kernel.orgSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

tools/perf/util/session.c

@@ -1847,10 +1847,17 @@ fetch_mmaped_event(struct perf_session *session,
 #define NUM_MMAPS 128
 #endif
 
+struct reader;
+
+typedef s64 (*reader_cb_t)(struct perf_session *session,
+			   union perf_event *event,
+			   u64 file_offset);
+
 struct reader {
-	int	fd;
-	u64	data_size;
-	u64	data_offset;
+	int		 fd;
+	u64		 data_size;
+	u64		 data_offset;
+	reader_cb_t	 process;
 };
 
 static int
@@ -1921,7 +1928,7 @@ reader__process_events(struct reader *rd, struct perf_session *session,
 	size = event->header.size;
 
 	if (size < sizeof(struct perf_event_header) ||
-	    (skip = perf_session__process_event(session, event, file_pos)) < 0) {
+	    (skip = rd->process(session, event, file_pos)) < 0) {
 		pr_err("%#" PRIx64 " [%#x]: failed to process type: %d\n",
 		       file_offset + head, event->header.size,
 		       event->header.type);
@@ -1947,12 +1954,20 @@ reader__process_events(struct reader *rd, struct perf_session *session,
 	return err;
 }
 
+static s64 process_simple(struct perf_session *session,
+			  union perf_event *event,
+			  u64 file_offset)
+{
+	return perf_session__process_event(session, event, file_offset);
+}
+
 static int __perf_session__process_events(struct perf_session *session)
 {
 	struct reader rd = {
 		.fd		= perf_data__fd(session->data),
 		.data_size	= session->header.data_size,
 		.data_offset	= session->header.data_offset,
+		.process	= process_simple,
 	};
 	struct ordered_events *oe = &session->ordered_events;
 	struct perf_tool *tool = session->tool;