OTP 23 support

4 files changed, 125 insertions, 4 deletions

diff --git a/src/nouveau/src/nouveau_fabric_info.erl b/src/nouveau/src/nouveau_fabric_info.erl
index 59e47094f..b5f928075 100644
--- a/src/nouveau/src/nouveau_fabric_info.erl
+++ b/src/nouveau/src/nouveau_fabric_info.erl
@@ -70,7 +70,7 @@ handle_message({ok, Info}, Worker, {Counters, Acc0}) ->
         nil ->
             C1 = fabric_dict:store(Worker, ok, Counters),
             C2 = fabric_view:remove_overlapping_shards(Worker, C1),
-            Acc1 = maps:merge_with(fun merge_info/3, Info, Acc0),
+            Acc1 = nouveau_maps:merge_with(fun merge_info/3, Info, Acc0),
             case fabric_dict:any(nil, C2) of
                 true ->
                     {ok, {C2, Acc1}};
diff --git a/src/nouveau/src/nouveau_fabric_search.erl b/src/nouveau/src/nouveau_fabric_search.erl
index 4e528cc93..ca101ba9c 100644
--- a/src/nouveau/src/nouveau_fabric_search.erl
+++ b/src/nouveau/src/nouveau_fabric_search.erl
@@ -217,5 +217,5 @@ merge_facets(FacetsA, null, _Limit) ->
 merge_facets(null, FacetsB, _Limit) ->
     FacetsB;
 merge_facets(FacetsA, FacetsB, _Limit) ->
-    Combiner = fun(_, V1, V2) -> maps:merge_with(fun(_, V3, V4) -> V3 + V4 end, V1, V2) end,
-    maps:merge_with(Combiner, FacetsA, FacetsB).
+    Combiner = fun(_, V1, V2) -> nouveau_maps:merge_with(fun(_, V3, V4) -> V3 + V4 end, V1, V2) end,
+    nouveau_maps:merge_with(Combiner, FacetsA, FacetsB).
diff --git a/src/nouveau/src/nouveau_httpd.erl b/src/nouveau/src/nouveau_httpd.erl
index 999acc7ea..8d27048a1 100644
--- a/src/nouveau/src/nouveau_httpd.erl
+++ b/src/nouveau/src/nouveau_httpd.erl
@@ -200,7 +200,7 @@ validate_query_arg(sort, Sort) ->
 validate_query_arg(ranges, undefined) ->
     null;
 validate_query_arg(ranges, {json, Ranges}) when is_map(Ranges) ->
-    maps:foreach(fun is_valid_range/2, Ranges),
+    nouveau_maps:foreach(fun is_valid_range/2, Ranges),
     Ranges;
 validate_query_arg(ranges, Ranges) ->
     validate_query_arg(ranges, {json, ?JSON_DECODE(Ranges, [return_maps])});
diff --git a/src/nouveau/src/nouveau_maps.erl b/src/nouveau/src/nouveau_maps.erl
new file mode 100644
index 000000000..81a145557
--- /dev/null
+++ b/src/nouveau/src/nouveau_maps.erl
@@ -0,0 +1,121 @@
+%%
+%%
+%% %CopyrightBegin%
+%%
+%% Copyright Ericsson AB 2013-2021. All Rights Reserved.
+%%
+%% Licensed under the Apache License, Version 2.0 (the "License");
+%% you may not use this file except in compliance with the License.
+%% You may obtain a copy of the License at
+%%
+%%     http://www.apache.org/licenses/LICENSE-2.0
+%%
+%% Unless required by applicable law or agreed to in writing, software
+%% distributed under the License is distributed on an "AS IS" BASIS,
+%% WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+%% See the License for the specific language governing permissions and
+%% limitations under the License.
+%%
+%% %CopyrightEnd%
+%%
+
+%% -*- erlang-indent-level: 4;indent-tabs-mode: nil -*-
+
+%% backport of OTP 24 map functions not present in 23.
+
+-module(nouveau_maps).
+
+-export([merge_with/3, foreach/2]).
+
+-if(?OTP_RELEASE >= 24).
+merge_with(Combiner, Map1, Map2) ->
+    maps:merge_with(Combiner, Map1, Map2).
+
+foreach(Fun, MapOrIter) ->
+    maps:foreach(Fun, MapOrIter).
+
+-else.
+
+merge_with(Combiner, Map1, Map2) when
+    is_map(Map1),
+    is_map(Map2),
+    is_function(Combiner, 3)
+->
+    case map_size(Map1) > map_size(Map2) of
+        true ->
+            Iterator = maps:iterator(Map2),
+            merge_with_1(
+                maps:next(Iterator),
+                Map1,
+                Map2,
+                Combiner
+            );
+        false ->
+            Iterator = maps:iterator(Map1),
+            merge_with_1(
+                maps:next(Iterator),
+                Map2,
+                Map1,
+                fun(K, V1, V2) -> Combiner(K, V2, V1) end
+            )
+    end;
+merge_with(Combiner, Map1, Map2) ->
+    error_with_info(
+        error_type_merge_intersect(Map1, Map2, Combiner),
+        [Combiner, Map1, Map2]
+    ).
+
+merge_with_1({K, V2, Iterator}, Map1, Map2, Combiner) ->
+    case Map1 of
+        #{K := V1} ->
+            NewMap1 = Map1#{K := Combiner(K, V1, V2)},
+            merge_with_1(maps:next(Iterator), NewMap1, Map2, Combiner);
+        #{} ->
+            merge_with_1(maps:next(Iterator), maps:put(K, V2, Map1), Map2, Combiner)
+    end;
+merge_with_1(none, Result, _, _) ->
+    Result.
+
+foreach(Fun, MapOrIter) when is_function(Fun, 2) ->
+    Iter =
+        if
+            is_map(MapOrIter) -> maps:iterator(MapOrIter);
+            true -> MapOrIter
+        end,
+    try maps:next(Iter) of
+        Next ->
+            foreach_1(Fun, Next)
+    catch
+        error:_ ->
+            error_with_info({badmap, MapOrIter}, [Fun, MapOrIter])
+    end;
+foreach(Pred, Map) ->
+    badarg_with_info([Pred, Map]).
+
+foreach_1(Fun, {K, V, Iter}) ->
+    Fun(K, V),
+    foreach_1(Fun, maps:next(Iter));
+foreach_1(_Fun, none) ->
+    ok.
+
+%% We must inline these functions so that the stacktrace points to
+%% the correct function.
+-compile({inline, [badarg_with_info/1, error_with_info/2]}).
+
+badarg_with_info(Args) ->
+    erlang:error(badarg, Args, [{error_info, #{module => erl_stdlib_errors}}]).
+
+error_with_info(Reason, Args) ->
+    erlang:error(Reason, Args, [{error_info, #{module => erl_stdlib_errors}}]).
+
+error_type_two_maps(M1, M2) when is_map(M1) ->
+    {badmap, M2};
+error_type_two_maps(M1, _M2) ->
+    {badmap, M1}.
+
+error_type_merge_intersect(M1, M2, Combiner) when is_function(Combiner, 3) ->
+    error_type_two_maps(M1, M2);
+error_type_merge_intersect(_M1, _M2, _Combiner) ->
+    badarg.
+
+-endif.