Simplify session reply frames

This commit is only refactoring.

To avoid confusion with reply and noreply gen_server return values, this
commit uses different return values for handle_frame/2.

deps/rabbit/src/rabbit_amqp_session.erl

@@ -500,15 +500,10 @@ handle_cast({frame_body, FrameBody},
             #state{cfg = #cfg{writer_pid = WriterPid,
                               channel_num = Ch}} = State0) ->
     try handle_frame(FrameBody, State0) of
-        {reply, Replies, State} when is_list(Replies) ->
-            lists:foreach(fun (Reply) ->
-                                  rabbit_amqp_writer:send_command(WriterPid, Ch, Reply)
-                          end, Replies),
-            noreply(State);
-        {reply, Reply, State} ->
-            rabbit_amqp_writer:send_command(WriterPid, Ch, Reply),
-            noreply(State);
-        {noreply, State} ->
+        {ok, ReplyFrames, State} ->
+            lists:foreach(fun(Frame) ->
+                                  rabbit_amqp_writer:send_command(WriterPid, Ch, Frame)
+                          end, ReplyFrames),
             noreply(State);
         {stop, _, _} = Stop ->
             Stop
@@ -913,7 +908,7 @@ handle_frame({Performative = #'v1_0.transfer'{handle = ?UINT(Handle)}, Paylaod},
         _ ->
             incoming_mgmt_link_transfer(Performative, Paylaod, State1)
     end,
-    reply0(Reply ++ Flows, State);
+    reply_frames(Reply ++ Flows, State);
 
 %% Although the AMQP message format [3.2] requires a body, it is valid to send a transfer frame without payload.
 %% For example, when a large multi transfer message is streamed using the ProtonJ2 client, the client could send
@@ -962,7 +957,7 @@ handle_frame(#'v1_0.flow'{handle = Handle} = Flow,
                         end
                 end
         end,
-    {noreply, S};
+    reply_frames([], S);
 
 handle_frame(#'v1_0.disposition'{role = ?AMQP_ROLE_RECEIVER,
                                  first = ?UINT(First),
@@ -981,7 +976,7 @@ handle_frame(#'v1_0.disposition'{role = ?AMQP_ROLE_RECEIVER,
     UnsettledMapSize = map_size(UnsettledMap0),
     case UnsettledMapSize of
         0 ->
-            {noreply, State0};
+            reply_frames([], State0);
         _ ->
             DispositionRangeSize = diff(Last, First) + 1,
             {Settled, UnsettledMap} =
@@ -1041,7 +1036,7 @@ handle_frame(#'v1_0.disposition'{role = ?AMQP_ROLE_RECEIVER,
                                                                  role = ?AMQP_ROLE_SENDER}]
                     end,
             State = handle_queue_actions(Actions, State1),
-            reply0(Reply, State)
+            reply_frames(Reply, State)
     end;
 
 handle_frame(#'v1_0.attach'{handle = ?UINT(Handle)} = Attach,
@@ -1095,9 +1090,9 @@ handle_frame(Detach = #'v1_0.detach'{handle = ?UINT(HandleInt)},
                           outgoing_pending = Pending,
                           queue_states = QStates},
     State = maybe_detach_mgmt_link(HandleInt, State1),
-    maybe_detach_reply(Detach, State, State0),
+    Reply = detach_reply(Detach, State, State0),
     publisher_or_consumer_deleted(State, State0),
-    {noreply, State};
+    reply_frames(Reply, State);
 
 handle_frame(#'v1_0.end'{},
              State0 = #state{cfg = #cfg{writer_pid = WriterPid,
@@ -1118,6 +1113,9 @@ handle_frame(Frame, _State) ->
                    "Unexpected frame ~tp",
                    [amqp10_framing:pprint(Frame)]).
 
+reply_frames(Frames, State) ->
+    {ok, session_flow_fields(Frames, State), State}.
+
 handle_attach(#'v1_0.attach'{
                 role = ?AMQP_ROLE_SENDER,
                 snd_settle_mode = ?V_1_0_SENDER_SETTLE_MODE_SETTLED,
@@ -1173,7 +1171,7 @@ handle_attach(#'v1_0.attach'{
     Flow = #'v1_0.flow'{handle = Handle,
                         delivery_count = DeliveryCount,
                         link_credit = ?UINT(?MAX_MANAGEMENT_LINK_CREDIT)},
-    reply0([Reply, Flow], State);
+    reply_frames([Reply, Flow], State);
 
 handle_attach(#'v1_0.attach'{
                 role = ?AMQP_ROLE_RECEIVER,
@@ -1228,7 +1226,7 @@ handle_attach(#'v1_0.attach'{
                %% Echo back that we will respect the client's requested max-message-size.
                max_message_size = MaybeMaxMessageSize,
                properties = Properties},
-    reply0(Reply, State);
+    reply_frames([Reply], State);
 
 handle_attach(#'v1_0.attach'{role = ?AMQP_ROLE_SENDER,
                              name = LinkName,
@@ -1275,7 +1273,7 @@ handle_attach(#'v1_0.attach'{role = ?AMQP_ROLE_SENDER,
             State = State0#state{incoming_links = IncomingLinks,
                                  permission_cache = PermCache},
             rabbit_global_counters:publisher_created(?PROTOCOL),
-            reply0([Reply, Flow], State);
+            reply_frames([Reply, Flow], State);
         {error, Reason} ->
             protocol_error(?V_1_0_AMQP_ERROR_INVALID_FIELD,
                            "Attach rejected: ~tp",
@@ -1416,7 +1414,7 @@ handle_attach(#'v1_0.attach'{role = ?AMQP_ROLE_RECEIVER,
                            end
                    end) of
                 {ok, Reply, State} ->
-                    reply0(Reply, State);
+                    reply_frames(Reply, State);
                 {error, Reason} ->
                     protocol_error(
                       ?V_1_0_AMQP_ERROR_INTERNAL_ERROR,
@@ -1842,11 +1840,6 @@ record_outgoing_unsettled(#pending_delivery{queue_ack_required = false}, State)
     %% Also, queue client already acked to queue on behalf of us.
     State.
 
-reply0([], State) ->
-    {noreply, State};
-reply0(Reply, State) ->
-    {reply, session_flow_fields(Reply, State), State}.
-
 %% Implements section "receiving a transfer" in 2.5.6
 session_flow_control_received_transfer(
   #state{next_incoming_id = NextIncomingId,
@@ -3278,26 +3271,22 @@ publisher_or_consumer_deleted(
 
 %% If we previously already sent a detach with an error condition, and the Detach we
 %% receive here is therefore the client's reply, do not reply again with a 3rd detach.
-maybe_detach_reply(
-  Detach,
-  #state{incoming_links = NewIncomingLinks,
-         outgoing_links = NewOutgoingLinks,
-         incoming_management_links = NewIncomingMgmtLinks,
-         outgoing_management_links = NewOutgoingMgmtLinks,
-         cfg = #cfg{writer_pid = WriterPid,
-                    channel_num = Ch}},
-  #state{incoming_links = OldIncomingLinks,
-         outgoing_links = OldOutgoingLinks,
-         incoming_management_links = OldIncomingMgmtLinks,
-         outgoing_management_links = OldOutgoingMgmtLinks})
+detach_reply(Detach,
+             #state{incoming_links = NewIncomingLinks,
+                    outgoing_links = NewOutgoingLinks,
+                    incoming_management_links = NewIncomingMgmtLinks,
+                    outgoing_management_links = NewOutgoingMgmtLinks},
+             #state{incoming_links = OldIncomingLinks,
+                    outgoing_links = OldOutgoingLinks,
+                    incoming_management_links = OldIncomingMgmtLinks,
+                    outgoing_management_links = OldOutgoingMgmtLinks})
   when map_size(NewIncomingLinks) < map_size(OldIncomingLinks) orelse
        map_size(NewOutgoingLinks) < map_size(OldOutgoingLinks) orelse
        map_size(NewIncomingMgmtLinks) < map_size(OldIncomingMgmtLinks) orelse
        map_size(NewOutgoingMgmtLinks) < map_size(OldOutgoingMgmtLinks) ->
-    Reply = Detach#'v1_0.detach'{error = undefined},
-    rabbit_amqp_writer:send_command(WriterPid, Ch, Reply);
-maybe_detach_reply(_, _, _) ->
-    ok.
+    [Detach#'v1_0.detach'{error = undefined}];
+detach_reply(_, _, _) ->
+    [].
 
 -spec maybe_detach_mgmt_link(link_handle(), state()) -> state().
 maybe_detach_mgmt_link(