Use keep_state_and_data in emqx_client to avoid unnecessary var binding

src/emqx_client.erl

@@ -743,12 +743,12 @@ waiting_for_connack(EventType, EventContent, State) ->
         false -> {stop, connack_timeout}
     end.
 
-connected({call, From}, subscriptions, State = #state{subscriptions = Subscriptions}) ->
-    {keep_state, State, [{reply, From, maps:to_list(Subscriptions)}]};
+connected({call, From}, subscriptions, #state{subscriptions = Subscriptions}) ->
+    {keep_state_and_data, [{reply, From, maps:to_list(Subscriptions)}]};
 
 connected({call, From}, info, State) ->
     Info = lists:zip(record_info(fields, state), tl(tuple_to_list(State))),
-    {keep_state, State, [{reply, From, Info}]};
+    {keep_state_and_data, [{reply, From, Info}]};
 
 connected({call, From}, pause, State) ->
     {keep_state, State#state{paused = true}, [{reply, From, ok}]};
@@ -756,11 +756,11 @@ connected({call, From}, pause, State) ->
 connected({call, From}, resume, State) ->
     {keep_state, State#state{paused = false}, [{reply, From, ok}]};
 
-connected({call, From}, get_properties, State = #state{properties = Properties}) ->
-    {keep_state, State, [{reply, From, Properties}]};
+connected({call, From}, get_properties, #state{properties = Properties}) ->
+    {keep_state_and_data, [{reply, From, Properties}]};
 
-connected({call, From}, client_id, State = #state{client_id = ClientId}) ->
-    {keep_state, State, [{reply, From, ClientId}]};
+connected({call, From}, client_id, #state{client_id = ClientId}) ->
+    {keep_state_and_data, [{reply, From, ClientId}]};
 
 connected({call, From}, {set_request_handler, RequestHandler}, State) ->
     {keep_state, State#state{request_handler = RequestHandler}, [{reply, From, ok}]};
@@ -843,8 +843,8 @@ connected(cast, {pubrel, PacketId, ReasonCode, Properties}, State) ->
 connected(cast, {pubcomp, PacketId, ReasonCode, Properties}, State) ->
     send_puback(?PUBCOMP_PACKET(PacketId, ReasonCode, Properties), State);
 
-connected(cast, ?PUBLISH_PACKET(_QoS, _PacketId), State = #state{paused = true}) ->
-    {keep_state, State};
+connected(cast, ?PUBLISH_PACKET(_QoS, _PacketId), #state{paused = true}) ->
+    keep_state_and_data;
 
 connected(cast, Packet = ?PUBLISH_PACKET(?QOS_0, _Topic, _PacketId, Properties, Payload),
           State) when Properties =/= undefined ->
@@ -897,7 +897,7 @@ connected(cast, ?PUBREL_PACKET(PacketId),
              end;
          error ->
              emqx_logger:warning("Unexpected PUBREL: ~p", [PacketId]),
-             {keep_state, State}
+             keep_state_and_data
      end;
 
 connected(cast, ?PUBCOMP_PACKET(_PacketId, _ReasonCode, _Properties) = PubComp, State) ->
@@ -910,7 +910,8 @@ connected(cast, ?SUBACK_PACKET(PacketId, Properties, ReasonCodes),
             %%TODO: Merge reason codes to subscriptions?
             Reply = {ok, Properties, ReasonCodes},
             {keep_state, NewState, [{reply, From, Reply}]};
-        false -> {keep_state, State}
+        false ->
+            keep_state_and_data
     end;
 
 connected(cast, ?UNSUBACK_PACKET(PacketId, Properties, ReasonCodes),
@@ -923,16 +924,18 @@ connected(cast, ?UNSUBACK_PACKET(PacketId, Properties, ReasonCodes),
                           end, Subscriptions, Topics),
             {keep_state, NewState#state{subscriptions = Subscriptions1},
              [{reply, From, {ok, Properties, ReasonCodes}}]};
-        false -> {keep_state, State}
+        false ->
+            keep_state_and_data
     end;
 
-connected(cast, ?PACKET(?PINGRESP), State = #state{pending_calls = []}) ->
-    {keep_state, State};
+connected(cast, ?PACKET(?PINGRESP), #state{pending_calls = []}) ->
+    keep_state_and_data;
 connected(cast, ?PACKET(?PINGRESP), State) ->
     case take_call(ping, State) of
         {value, #call{from = From}, NewState} ->
             {keep_state, NewState, [{reply, From, pong}]};
-        false -> {keep_state, State}
+        false ->
+            keep_state_and_data
     end;
 
 connected(cast, ?DISCONNECT_PACKET(ReasonCode, Properties), State) ->
@@ -1009,17 +1012,17 @@ handle_event(info, {'EXIT', Owner, Reason}, _, State = #state{owner = Owner}) ->
     emqx_logger:debug("[~p] Got EXIT from owner, Reason: ~p", [?MODULE, Reason]),
     {stop, {shutdown, Reason}, State};
 
-handle_event(info, {inet_reply, _Sock, ok}, _, State) ->
-    {keep_state, State};
+handle_event(info, {inet_reply, _Sock, ok}, _, _State) ->
+    keep_state_and_data;
 
 handle_event(info, {inet_reply, _Sock, {error, Reason}}, _, State) ->
     emqx_logger:error("[~p] got tcp error: ~p", [?MODULE, Reason]),
     {stop, {shutdown, Reason}, State};
 
-handle_event(EventType, EventContent, StateName, StateData) ->
+handle_event(EventType, EventContent, StateName, _StateData) ->
     emqx_logger:error("State: ~s, Unexpected Event: (~p, ~p)",
                       [StateName, EventType, EventContent]),
-    {keep_state, StateData}.
+    keep_state_and_data.
 
 %% Mandatory callback functions
 terminate(Reason, _StateName, State = #state{socket = Socket}) ->