Make ets diameter_stats a set

There's no need for it to be ordered, and the ordering has been seen to
have an unexpectedly negative impact on performance in some cases. Order
when retrieving statistics instead, so as not to change the
presentation in diameter:service_info/2.

1 files changed, 9 insertions, 7 deletions

diff --git a/lib/diameter/src/base/diameter_stats.erl b/lib/diameter/src/base/diameter_stats.erl
index d2c760317a..79a5c7b947 100644
--- a/lib/diameter/src/base/diameter_stats.erl
+++ b/lib/diameter/src/base/diameter_stats.erl
@@ -142,9 +142,14 @@ read(Refs, B) ->
     L.
 
 to_refdict(L) ->
-    lists:foldl(fun({{C,R}, N}, D) -> orddict:append(R, {C,N}, D) end,
-                orddict:new(),
-                L).
+    lists:foldl(fun append/2, orddict:new(), L).
+
+%% Order both references and counters in the returned list.
+append({{Ctr, Ref}, N}, Dict) ->
+    orddict:update(Ref,
+                   fun(D) -> orddict:store(Ctr, N, D) end,
+                   [{Ctr, N}],
+                   Dict).
 
 %% ---------------------------------------------------------------------------
 %% # sum(Refs)
@@ -220,10 +225,7 @@ uptime() ->
 %% ----------------------------------------------------------
 
 init([]) ->
-    ets:new(?TABLE, [named_table,
-                     ordered_set,
-                     public,
-                     {write_concurrency, true}]),
+    ets:new(?TABLE, [named_table, set, public, {write_concurrency, true}]),
     {ok, #state{}}.
 
 %% ----------------------------------------------------------