[PATCH v4 4/7] perf util: Link stream pair

[Jin Yao]

In previous patch, we have created an evsel_streams for one event,
and top N hottest streams will be saved in a stream array in
evsel_streams.

This patch compares total streams among two evsel_streams.

Once two streams are fully matched, they will be linked as
a pair. From the pair, we can know which streams are matched.

Signed-off-by: Jin Yao <yao.jin@xxxxxxxxxxxxxxx>
---
 v4:
   - New patch in v4.

 tools/perf/util/stream.c | 53 ++++++++++++++++++++++++++++++++++++++++
 tools/perf/util/stream.h |  4 +++
 2 files changed, 57 insertions(+)

diff --git a/tools/perf/util/stream.c b/tools/perf/util/stream.c
index 7f538d1085ef..76896a790798 100644
--- a/tools/perf/util/stream.c
+++ b/tools/perf/util/stream.c
@@ -161,3 +161,56 @@ struct evsel_streams *evsel_streams_get(struct evsel_streams *es,
 
 	return NULL;
 }
+
+static struct stream *stream_callchain_match(struct stream *base_stream,
+					     struct evsel_streams *es_pair)
+{
+	for (int i = 0; i < es_pair->nr_streams; i++) {
+		struct stream *pair_stream = &es_pair->streams[i];
+
+		if (callchain_cnode_matched(base_stream->cnode,
+					    pair_stream->cnode)) {
+			return pair_stream;
+		}
+	}
+
+	return NULL;
+}
+
+static struct stream *stream_match(struct stream *base_stream,
+				   struct evsel_streams *es_pair,
+				   enum stream_type stream_type)
+{
+	if (stream_type == STREAM_CALLCHAIN)
+		return stream_callchain_match(base_stream, es_pair);
+
+	return NULL;
+}
+
+static void stream_link(struct stream *base_stream, struct stream *pair_stream,
+			enum stream_type stream_type)
+{
+	if (stream_type == STREAM_CALLCHAIN) {
+		base_stream->pair_cnode = pair_stream->cnode;
+		pair_stream->pair_cnode = base_stream->cnode;
+	}
+}
+
+void match_evsel_streams(struct evsel_streams *es_base,
+			 struct evsel_streams *es_pair)
+{
+	if (es_base->stream_type != es_pair->stream_type)
+		return;
+
+	for (int i = 0; i < es_base->nr_streams; i++) {
+		struct stream *base_stream = &es_base->streams[i];
+		struct stream *pair_stream;
+
+		pair_stream = stream_match(base_stream, es_pair,
+					   es_base->stream_type);
+		if (pair_stream) {
+			stream_link(base_stream, pair_stream,
+				    es_base->stream_type);
+		}
+	}
+}
diff --git a/tools/perf/util/stream.h b/tools/perf/util/stream.h
index 705aa7cde3de..53f34e63f8fb 100644
--- a/tools/perf/util/stream.h
+++ b/tools/perf/util/stream.h
@@ -11,6 +11,7 @@ enum stream_type {
 
 struct stream {
 	struct callchain_node	*cnode;
+	struct callchain_node	*pair_cnode;
 };
 
 struct evsel_streams {
@@ -30,4 +31,7 @@ struct evsel_streams *perf_evlist__create_streams(struct evlist *evlist,
 struct evsel_streams *evsel_streams_get(struct evsel_streams *es,
 					int nr_evsel, int evsel_idx);
 
+void match_evsel_streams(struct evsel_streams *es_base,
+			 struct evsel_streams *es_pair);
+
 #endif /* __PERF_STREAM_H */
-- 
2.17.1