merge bug23378 into default

5 files changed, 58 insertions, 36 deletions

diff --git a/src/rabbit_exchange.erl b/src/rabbit_exchange.erl
index 5f4fb9ec87..9e98448d63 100644
--- a/src/rabbit_exchange.erl
+++ b/src/rabbit_exchange.erl
@@ -326,34 +326,34 @@ route(#exchange{name = #resource{virtual_host = VHost,
             %% Optimisation
             [rabbit_misc:r(VHost, queue, RK) || RK <- lists:usort(RKs)];
         {Decorators, _} ->
-            QNames = route1(Delivery, {[X], XName, []}),
-            lists:usort(decorate_route(Decorators, X, Delivery, QNames))
+            lists:usort(route1(Delivery, Decorators, {[X], XName, []}))
     end.
 
-decorate_route([], _X, _Delivery, QNames) ->
+route1(_, _, {[], _, QNames}) ->
     QNames;
-decorate_route(Decorators, X, Delivery, QNames) ->
-    QNames ++
-        lists:append([Decorator:route(X, Delivery) || Decorator <- Decorators]).
-
-route1(_, {[], _, QNames}) ->
-    QNames;
-route1(Delivery, {[X = #exchange{type = Type} | WorkList], SeenXs, QNames}) ->
-    DstNames = process_alternate(
-                 X, ((type_to_module(Type)):route(X, Delivery))),
-    route1(Delivery,
+route1(Delivery, Decorators,
+       {[X = #exchange{type = Type} | WorkList], SeenXs, QNames}) ->
+    ExchangeDests  = (type_to_module(Type)):route(X, Delivery),
+    DecorateDests  = process_decorators(X, Decorators, Delivery),
+    AlternateDests = process_alternate(X, ExchangeDests),
+    route1(Delivery, Decorators,
            lists:foldl(fun process_route/2, {WorkList, SeenXs, QNames},
-                       DstNames)).
+                       AlternateDests ++ DecorateDests  ++ ExchangeDests)).
 
-process_alternate(#exchange{arguments = []}, Results) -> %% optimisation
-    Results;
+process_alternate(#exchange{arguments = []}, _Results) -> %% optimisation
+    [];
 process_alternate(#exchange{name = XName, arguments = Args}, []) ->
     case rabbit_misc:r_arg(XName, exchange, Args, <<"alternate-exchange">>) of
         undefined -> [];
         AName     -> [AName]
     end;
-process_alternate(_X, Results) ->
-    Results.
+process_alternate(_X, _Results) ->
+    [].
+
+process_decorators(_, [], _) -> %% optimisation
+    [];
+process_decorators(X, Decorators, Delivery) ->
+    lists:append([Decorator:route(X, Delivery) || Decorator <- Decorators]).
 
 process_route(#resource{kind = exchange} = XName,
               {_WorkList, XName, _QNames} = Acc) ->
diff --git a/src/rabbit_exchange_decorator.erl b/src/rabbit_exchange_decorator.erl
index 8f17adfc23..040b55dbb0 100644
--- a/src/rabbit_exchange_decorator.erl
+++ b/src/rabbit_exchange_decorator.erl
@@ -57,12 +57,10 @@
 -callback remove_bindings(serial(), rabbit_types:exchange(),
                           [rabbit_types:binding()]) -> 'ok'.
 
-%% called after exchange routing
-%% return value is a list of queues to be added to the list of
-%% destination queues. decorators must register separately for
-%% this callback using exchange_decorator_route.
--callback route(rabbit_types:exchange(), rabbit_types:delivery()) ->
-    [rabbit_amqqueue:name()].
+%% Decorators can optionally implement route/2 which allows additional
+%% destinations to be added to the routing decision.
+%% -callback route(rabbit_types:exchange(), rabbit_types:delivery()) ->
+%%     [rabbit_amqqueue:name() | rabbit_exchange:name()].
 
 -else.
 
@@ -70,7 +68,7 @@
 
 behaviour_info(callbacks) ->
     [{description, 0}, {serialise_events, 1}, {create, 2}, {delete, 3},
-     {policy_changed, 2}, {add_binding, 3}, {remove_bindings, 3}, {route, 2}];
+     {policy_changed, 2}, {add_binding, 3}, {remove_bindings, 3}];
 behaviour_info(_Other) ->
     undefined.
 
diff --git a/src/rabbit_node_monitor.erl b/src/rabbit_node_monitor.erl
index de53b7f0b3..3872f3dfa2 100644
--- a/src/rabbit_node_monitor.erl
+++ b/src/rabbit_node_monitor.erl
@@ -318,6 +318,9 @@ alive_nodes() ->
     Nodes = rabbit_mnesia:cluster_nodes(all),
     [N || N <- Nodes, pong =:= net_adm:ping(N)].
 
+alive_rabbit_nodes() ->
+    [N || N <- alive_nodes(), rabbit_nodes:is_running(N, rabbit)].
+
 await_cluster_recovery() ->
     rabbit_log:warning("Cluster minority status detected - awaiting recovery~n",
                        []),
@@ -346,7 +349,7 @@ handle_dead_rabbit_state(State = #state{partitions = Partitions}) ->
     %% that we do not attempt to deal with individual (other) partitions
     %% going away. It's only safe to forget anything about partitions when
     %% there are no partitions.
-    Partitions1 = case Partitions -- (Partitions -- alive_nodes()) of
+    Partitions1 = case Partitions -- (Partitions -- alive_rabbit_nodes()) of
                       [] -> [];
                       _  -> Partitions
                   end,
diff --git a/src/rabbit_registry.erl b/src/rabbit_registry.erl
index 3514e7806c..acdc2cffae 100644
--- a/src/rabbit_registry.erl
+++ b/src/rabbit_registry.erl
@@ -84,12 +84,34 @@ internal_binary_to_type(TypeBin) when is_binary(TypeBin) ->
 internal_register(Class, TypeName, ModuleName)
   when is_atom(Class), is_binary(TypeName), is_atom(ModuleName) ->
     ok = sanity_check_module(class_module(Class), ModuleName),
-    true = ets:insert(?ETS_NAME,
-                      {{Class, internal_binary_to_type(TypeName)}, ModuleName}),
+    RegArg = {{Class, internal_binary_to_type(TypeName)}, ModuleName},
+    true = ets:insert(?ETS_NAME, RegArg),
+    conditional_register(RegArg),
     ok.
 
 internal_unregister(Class, TypeName) ->
-    true = ets:delete(?ETS_NAME, {Class, internal_binary_to_type(TypeName)}),
+    UnregArg = {Class, internal_binary_to_type(TypeName)},
+    conditional_unregister(UnregArg),
+    true = ets:delete(?ETS_NAME, UnregArg),
+    ok.
+
+%% register exchange decorator route callback only when implemented,
+%% in order to avoid unnecessary decorator calls on the fast
+%% publishing path
+conditional_register({{exchange_decorator, Type}, ModuleName}) ->
+    case erlang:function_exported(ModuleName, route, 2) of
+        true  -> true = ets:insert(?ETS_NAME,
+                                   {{exchange_decorator_route, Type},
+                                    ModuleName});
+        false -> ok
+    end;
+conditional_register(_) ->
+    ok.
+
+conditional_unregister({exchange_decorator, Type}) ->
+    true = ets:delete(?ETS_NAME, {exchange_decorator_route, Type}),
+    ok;
+conditional_unregister(_) ->
     ok.
 
 sanity_check_module(ClassModule, Module) ->
@@ -104,12 +126,11 @@ sanity_check_module(ClassModule, Module) ->
         true                  -> ok
     end.
 
-class_module(exchange)                 -> rabbit_exchange_type;
-class_module(auth_mechanism)           -> rabbit_auth_mechanism;
-class_module(runtime_parameter)        -> rabbit_runtime_parameter;
-class_module(exchange_decorator)       -> rabbit_exchange_decorator;
-class_module(exchange_decorator_route) -> rabbit_exchange_decorator;
-class_module(policy_validator)         -> rabbit_policy_validator.
+class_module(exchange)           -> rabbit_exchange_type;
+class_module(auth_mechanism)     -> rabbit_auth_mechanism;
+class_module(runtime_parameter)  -> rabbit_runtime_parameter;
+class_module(exchange_decorator) -> rabbit_exchange_decorator;
+class_module(policy_validator)   -> rabbit_policy_validator.
 
 %%---------------------------------------------------------------------------
 
diff --git a/src/rabbit_tests.erl b/src/rabbit_tests.erl
index 1188c5549a..cd8fa72052 100644
--- a/src/rabbit_tests.erl
+++ b/src/rabbit_tests.erl
@@ -1580,7 +1580,7 @@ control_action(Command, Node, Args, Opts) ->
 
 info_action(Command, Args, CheckVHost) ->
     ok = control_action(Command, []),
-    if CheckVHost -> ok = control_action(Command, []);
+    if CheckVHost -> ok = control_action(Command, [], ["-p", "/"]);
        true       -> ok
     end,
     ok = control_action(Command, lists:map(fun atom_to_list/1, Args)),