[PATCH v3 3/7] perf util: Return per-event callchain streams

[Jin Yao <yao.jin@linux.intel.com>]

In previous patch, we have created a 'struct callchain_streams'
array and each array entry contains per-event callchain streams.

This patch returns the pointer of per-event callchain streams
according to the evsel_idx.

Signed-off-by: Jin Yao <yao.jin@linux.intel.com>
---
 tools/perf/util/callchain.c | 12 ++++++++++++
 tools/perf/util/callchain.h |  4 ++++
 2 files changed, 16 insertions(+)

diff --git a/tools/perf/util/callchain.c b/tools/perf/util/callchain.c
index 0c028caaeb19..bf66f33debd4 100644
--- a/tools/perf/util/callchain.c
+++ b/tools/perf/util/callchain.c
@@ -1721,3 +1721,15 @@ struct callchain_streams *callchain_evsel_streams_create(struct evlist *evlist,
 	*nr_evsel_streams = nr_evsel;
 	return callchain_streams;
 }
+
+struct callchain_streams *callchain_evsel_streams_get(struct callchain_streams *cs,
+						      int nr_streams_max,
+						      int evsel_idx)
+{
+	for (int i = 0; i < nr_streams_max; i++) {
+		if (cs[i].evsel_idx == evsel_idx)
+			return &cs[i];
+	}
+
+	return NULL;
+}
diff --git a/tools/perf/util/callchain.h b/tools/perf/util/callchain.h
index 6a93ad84d395..6ff9d86d74d3 100644
--- a/tools/perf/util/callchain.h
+++ b/tools/perf/util/callchain.h
@@ -313,4 +313,8 @@ struct callchain_streams *callchain_evsel_streams_create(struct evlist *evlist,
 							 int nr_streams_max,
 							 int *nr_evsel_streams);
 
+struct callchain_streams *callchain_evsel_streams_get(struct callchain_streams *cs,
+						      int nr_streams_max,
+						      int evsel_idx);
+
 #endif	/* __PERF_CALLCHAIN_H */
-- 
2.17.1