perf evsel: Precalculate the sample size

So that we don't have to store it in the perf_session instance, because
in the future perf_session instances may have multiple evlists, each
with different sample_type/sizes.

Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Namhyung Kim <namhyung@gmail.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/n/tip-ptod86fxkpgq3h62m9refkv4@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
diff --git a/tools/perf/util/session.c b/tools/perf/util/session.c
index 8e4f075..b8da60d 100644
--- a/tools/perf/util/session.c
+++ b/tools/perf/util/session.c
@@ -16,6 +16,19 @@
 #include "cpumap.h"
 #include "event-parse.h"
 
+int perf_session__parse_sample(struct perf_session *session,
+			       const union perf_event *event,
+			       struct perf_sample *sample)
+{
+	struct perf_evsel *first;
+	first = list_entry(session->evlist->entries.next, struct perf_evsel, node);
+
+	return perf_event__parse_sample(event, session->sample_type,
+					first->sample_size,
+					session->sample_id_all, sample,
+					session->header.needs_swap);
+}
+
 static int perf_session__open(struct perf_session *self, bool force)
 {
 	struct stat input_stat;
@@ -83,7 +96,6 @@
 void perf_session__update_sample_type(struct perf_session *self)
 {
 	self->sample_type = perf_evlist__sample_type(self->evlist);
-	self->sample_size = __perf_evsel__sample_size(self->sample_type);
 	self->sample_id_all = perf_evlist__sample_id_all(self->evlist);
 	self->id_hdr_size = perf_evlist__id_hdr_size(self->evlist);
 	self->host_machine.id_hdr_size = self->id_hdr_size;