perf diff: Move hists__match to the hists lib

Its not 'diff' specific and will be useful for other use cases, like
bucketizing multiple events in a single session.

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-o35urjgxfxxm70aw1wa81s4w@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

1 files changed, 37 insertions, 0 deletions

diff --git a/tools/perf/util/hist.c b/tools/perf/util/hist.c
index f42de79d2e6b..c1de3b05fe09 100644
--- a/tools/perf/util/hist.c
+++ b/tools/perf/util/hist.c
@@ -716,3 +716,40 @@ void hists__inc_nr_events(struct hists *hists, u32 type)
         ++hists->stats.nr_events[0];
         ++hists->stats.nr_events[type];
 }
+
+static struct hist_entry *hists__find_entry(struct hists *hists,
+                                            struct hist_entry *he)
+{
+        struct rb_node *n = hists->entries.rb_node;
+
+        while (n) {
+                struct hist_entry *iter = rb_entry(n, struct hist_entry, rb_node);
+                int64_t cmp = hist_entry__cmp(he, iter);
+
+                if (cmp < 0)
+                        n = n->rb_left;
+                else if (cmp > 0)
+                        n = n->rb_right;
+                else
+                        return iter;
+        }
+
+        return NULL;
+}
+
+/*
+ * Look for pairs to link to the leader buckets (hist_entries):
+ */
+void hists__match(struct hists *leader, struct hists *other)
+{
+        struct rb_node *nd;
+        struct hist_entry *pos, *pair;
+
+        for (nd = rb_first(&leader->entries); nd; nd = rb_next(nd)) {
+                pos  = rb_entry(nd, struct hist_entry, rb_node);
+                pair = hists__find_entry(other, pos);
+
+                if (pair)
+                        hist__entry_add_pair(pos, pair);
+        }
+}