Revert "Merge pull request #10453 from rabbitmq/rabbitmq-server-10416"

This reverts commit 40ff91a, reversing
changes made to d57a310.

Author: dumbbell

deps/rabbitmq_federation/src/rabbit_federation_exchange_link_sup_sup.erl

@@ -66,87 +66,42 @@ start_link() ->
 %% Note that the next supervisor down, rabbit_federation_link_sup, is common
 %% between exchanges and queues.
 start_child(X) ->
-    Result =
-        case child_exists(X) orelse
-            mirrored_supervisor:start_child(
-              ?SUPERVISOR,
-              {id(X), {rabbit_federation_link_sup, start_link, [X]},
-               transient, ?SUPERVISOR_WAIT, supervisor,
-               [rabbit_federation_link_sup]}) of
-            true ->
-                already_started;
-            {ok, _Pid} ->
-                ok;
-            {error, {already_started, _Pid}} ->
-                already_started;
-            %% A link returned {stop, gone}, the link_sup shut down, that's OK.
-            {error, {shutdown, _}} ->
-                ok
-        end,
-    case Result of
-        ok ->
-            ok;
-        already_started ->
-            #exchange{name = ExchangeName} = X,
-            rabbit_log_federation:debug("Federation link for exchange ~tp was already started",
-                                        [rabbit_misc:rs(ExchangeName)]),
-            ok
+    case mirrored_supervisor:start_child(
+           ?SUPERVISOR,
+           {id(X), {rabbit_federation_link_sup, start_link, [X]},
+            transient, ?SUPERVISOR_WAIT, supervisor,
+            [rabbit_federation_link_sup]}) of
+        {ok, _Pid}               -> ok;
+        {error, {already_started, _Pid}} ->
+          #exchange{name = ExchangeName} = X,
+          rabbit_log_federation:debug("Federation link for exchange ~tp was already started",
+                                      [rabbit_misc:rs(ExchangeName)]),
+          ok;
+        %% A link returned {stop, gone}, the link_sup shut down, that's OK.
+        {error, {shutdown, _}} -> ok
     end.
 
-
-child_exists(Name) ->
-    Id = id(Name),
-    %% older format, pre-3.13.0
-    OldId = old_id(Name),
-    lists:any(fun ({ChildId, _, _, _}) ->
-                      ChildId =:= Id orelse ChildId =:= OldId
-              end,
-              mirrored_supervisor:which_children(?SUPERVISOR)).
-
 adjust({clear_upstream, VHost, UpstreamName}) ->
-    _ = [rabbit_federation_link_sup:adjust(Pid, exchange_record_from_child_id(Id), {clear_upstream, UpstreamName}) ||
-            {Id, Pid, _, _} <- mirrored_supervisor:which_children(?SUPERVISOR),
-            virtual_host_name_from_child_id(Id) =:= VHost
-        ],
+    _ = [rabbit_federation_link_sup:adjust(Pid, X, {clear_upstream, UpstreamName}) ||
+            {{_, #exchange{name = Name} = X}, Pid, _, _} <- mirrored_supervisor:which_children(?SUPERVISOR),
+            Name#resource.virtual_host == VHost],
     ok;
 adjust(Reason) ->
-    _ = [rabbit_federation_link_sup:adjust(Pid, exchange_record_from_child_id(Id), Reason) ||
-            {Id, Pid, _, _} <- mirrored_supervisor:which_children(?SUPERVISOR)
-        ],
+    _ = [rabbit_federation_link_sup:adjust(Pid, X, Reason) ||
+            {{_, X}, Pid, _, _} <- mirrored_supervisor:which_children(?SUPERVISOR)],
     ok.
 
 stop_child(X) ->
-    Result =
-        case stop_and_delete_child(id(X)) of
-            ok -> ok;
-            {error, not_found} = Error ->
-                case rabbit_khepri:is_enabled() of
-                    true ->
-                        %% Old id format is not supported by Khepri and cannot exist there
-                        Error;
-                    false ->
-                        %% try old format, pre-3.13.0
-                        stop_and_delete_child(old_id(X))
-                end
-        end,
-    case Result of
-        ok ->
-            ok;
-        {error, Err} ->
-            #exchange{name = ExchangeName} = X,
-            rabbit_log_federation:warning(
-              "Attempt to stop a federation link for exchange ~tp failed: ~tp",
-              [rabbit_misc:rs(ExchangeName), Err]),
-            ok
-    end.
-
-stop_and_delete_child(Id) ->
-    case mirrored_supervisor:terminate_child(?SUPERVISOR, Id) of
-        ok ->
-            ok = mirrored_supervisor:delete_child(?SUPERVISOR, Id);
-        {error, not_found} = Error ->
-            Error
-    end.
+    case mirrored_supervisor:terminate_child(?SUPERVISOR, id(X)) of
+      ok -> ok;
+      {error, Err} ->
+        #exchange{name = ExchangeName} = X,
+        rabbit_log_federation:warning(
+          "Attempt to stop a federation link for exchange ~tp failed: ~tp",
+          [rabbit_misc:rs(ExchangeName), Err]),
+        ok
+    end,
+    ok = mirrored_supervisor:delete_child(?SUPERVISOR, id(X)).
 
 %%----------------------------------------------------------------------------
 
@@ -160,20 +115,3 @@ id(X = #exchange{policy = Policy}) ->
 
 simple_id(#exchange{name = #resource{virtual_host = VHost, name = Name}}) ->
     [exchange, VHost, Name].
-
-%% Old child id format, pre 3.13.0
-old_id(X = #exchange{policy = Policy}) ->
-    X1 = rabbit_exchange:immutable(X),
-    X1#exchange{policy = Policy}.
-
-%% New child id format, introduced in 3.13.0 for Khepri
-exchange_record_from_child_id({_, #exchange{} = XR}) ->
-    XR;
-%% Old child id format, pre-3.13.0
-exchange_record_from_child_id(#exchange{} = XR) ->
-    XR.
-
-virtual_host_name_from_child_id({_, #exchange{name = Res}}) ->
-    Res#resource.virtual_host;
-virtual_host_name_from_child_id(#exchange{name = Res}) ->
-    Res#resource.virtual_host.