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authorAnders Svensson <[email protected]>2017-04-28 08:59:31 +0200
committerAnders Svensson <[email protected]>2017-06-13 13:50:06 +0200
commit4bfccba1943a21b1f723607f5b8e25773e48d98d (patch)
treecbfd8c49649bf6e2358dbbb5603f6073db07363e /lib
parentcfbe969341068623e609fd25c9c5f56b1fdc9458 (diff)
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Avoid recreating records
This old construction is approximately two to four times slower from best (no elements modified) to worst (all modified) case, with the new construction having constant speed.
Diffstat (limited to 'lib')
-rw-r--r--lib/diameter/src/base/diameter_lib.erl31
-rw-r--r--lib/diameter/src/base/diameter_traffic.erl18
2 files changed, 14 insertions, 35 deletions
diff --git a/lib/diameter/src/base/diameter_lib.erl b/lib/diameter/src/base/diameter_lib.erl
index 3928769b5e..58b9a29812 100644
--- a/lib/diameter/src/base/diameter_lib.erl
+++ b/lib/diameter/src/base/diameter_lib.erl
@@ -37,7 +37,6 @@
ipaddr/1,
spawn_opts/2,
wait/1,
- fold_tuple/3,
fold_n/3,
for_n/2,
log/4]).
@@ -341,36 +340,6 @@ down(MRef)
receive {'DOWN', MRef, process, _, _} = T -> T end.
%% ---------------------------------------------------------------------------
-%% # fold_tuple/3
-%% ---------------------------------------------------------------------------
-
--spec fold_tuple(N, T0, T)
- -> tuple()
- when N :: pos_integer(),
- T0 :: tuple(),
- T :: tuple()
- | undefined.
-
-%% Replace fields in T0 by those of T starting at index N, unless the
-%% new value is 'undefined'.
-%%
-%% eg. fold_tuple(2, Hdr, #diameter_header{end_to_end_id = 42})
-
-fold_tuple(_, T, undefined) ->
- T;
-
-fold_tuple(N, T0, T1) ->
- {_, T} = lists:foldl(fun(V, {I,_} = IT) -> {I+1, ft(V, IT)} end,
- {N, T0},
- lists:nthtail(N-1, tuple_to_list(T1))),
- T.
-
-ft(undefined, {_, T}) ->
- T;
-ft(Value, {Idx, T}) ->
- setelement(Idx, T, Value).
-
-%% ---------------------------------------------------------------------------
%% # fold_n/3
%% ---------------------------------------------------------------------------
diff --git a/lib/diameter/src/base/diameter_traffic.erl b/lib/diameter/src/base/diameter_traffic.erl
index 4a5df722e7..72fb92dcf9 100644
--- a/lib/diameter/src/base/diameter_traffic.erl
+++ b/lib/diameter/src/base/diameter_traffic.erl
@@ -1438,11 +1438,21 @@ make_retransmit_header(Hdr) ->
Hdr#diameter_header{is_retransmitted = true}.
%% fold_record/2
+%%
+%% Replace elements in the first record by those in the second that
+%% differ from undefined.
+
+fold_record(Rec0, undefined) ->
+ Rec0;
+fold_record(Rec0, Rec) ->
+ list_to_tuple(fold(tuple_to_list(Rec0), tuple_to_list(Rec))).
-fold_record(undefined, R) ->
- R;
-fold_record(Rec, R) ->
- diameter_lib:fold_tuple(2, Rec, R).
+fold([], []) ->
+ [];
+fold([H | T0], [undefined | T]) ->
+ [H | fold(T0, T)];
+fold([_ | T0], [H | T]) ->
+ [H | fold(T0, T)].
%% send_R/6