fix ws command

apps/iot/src/websocket/ws_channel.erl

@@ -14,6 +14,7 @@
 -export([init/2]).
 -export([websocket_init/1, websocket_handle/2, websocket_info/2, terminate/3]).
 -export([publish/3, stop/2, send/2]).
+-export([publish_command/3, send_command/2]).
 
 -record(state, {
     uuid :: undefined | binary(),
@@ -23,7 +24,9 @@
     packet_id = 1 :: integer(),
 
     %% 请求响应的对应关系
-    inflight = #{}
+    inflight = #{},
+    %% 指令的对应关系
+    cmd_inflight = #{}
 }).
 
 %% 向通道中写入消息
@@ -38,6 +41,20 @@ publish(Pid, ReceiverPid, Msg) when is_pid(Pid), is_binary(Msg) ->
 send(Pid, Msg) when is_pid(Pid), is_binary(Msg) ->
     Pid ! {send, Msg}.
 
+%% 发送指令信息
+
+%% 向通道中写入消息
+-spec publish_command(Pid :: pid(), ReceiverPid :: pid(), Msg :: binary()) -> Ref :: reference().
+publish_command(Pid, ReceiverPid, Cmd) when is_pid(Pid), is_binary(Cmd) ->
+    Ref = make_ref(),
+    Pid ! {publish_command, ReceiverPid, Ref, Cmd},
+    Ref.
+
+%% 向通道中写入消息
+-spec send_command(Pid :: pid(), Cmd :: binary()) -> no_return().
+send_command(Pid, Cmd) when is_pid(Pid), is_binary(Cmd) ->
+    Pid ! {send_command, Cmd}.
+
 %% 关闭方法
 -spec stop(Pid :: pid(), Reason :: any()) -> no_return().
 stop(undefined, _Reason) ->
@@ -140,6 +157,25 @@ websocket_handle({binary, <<?PACKET_PUBLISH_RESPONSE, PacketId:32, Body/binary>>
             {ok, State#state{inflight = NInflight}}
     end;
 
+%% 命令的响应
+websocket_handle({binary, <<?PACKET_COMMAND_RESPONSE, PacketId:32, Body/binary>>}, State = #state{uuid = UUID, cmd_inflight = CmdInflight}) when PacketId > 0 ->
+    lager:debug("[ws_channel] uuid: ~p, get command response message: ~p, packet_id: ~p", [UUID, Body, PacketId]),
+    case maps:take(PacketId, CmdInflight) of
+        error ->
+            lager:warning("[ws_channel] get unknown command response message: ~p, packet_id: ~p", [Body, PacketId]),
+            {ok, State};
+        {{ReceiverPid, Ref}, NCmdInflight} ->
+            case is_pid(ReceiverPid) andalso is_process_alive(ReceiverPid) of
+                true when Body == <<>> ->
+                    ReceiverPid ! {cmd_response, Ref};
+                true ->
+                    ReceiverPid ! {cmd_response, Ref, Body};
+                false ->
+                    lager:warning("[ws_channel] get command response message: ~p, packet_id: ~p, but receiver_pid is deaded", [Body, PacketId])
+            end,
+            {ok, State#state{cmd_inflight = NCmdInflight}}
+    end;
+
 websocket_handle(Info, State) ->
     lager:error("[ws_channel] get a unknown message: ~p, channel will closed", [Info]),
     {stop, State}.
@@ -158,6 +194,15 @@ websocket_info({publish, ReceiverPid, Ref, Msg}, State = #state{packet_id = Pack
 websocket_info({send, Msg}, State) when is_binary(Msg) ->
     {reply, {binary, <<?PACKET_PUBLISH, 0:32, Msg/binary>>}, State};
 
+%% 下发指令
+websocket_info({publish_command, ReceiverPid, Ref, Cmd}, State = #state{packet_id = PacketId, cmd_inflight = CmdInflight}) when is_binary(Cmd) ->
+    NCmdInflight = maps:put(PacketId, {ReceiverPid, Ref}, CmdInflight),
+    {reply, {binary, <<?PACKET_COMMAND, PacketId:32, Cmd/binary>>}, State#state{packet_id = PacketId + 1, cmd_inflight = NCmdInflight}};
+
+%% 发送指令, 不需要等待回复
+websocket_info({send_command, Cmd}, State) when is_binary(Cmd) ->
+    {reply, {binary, <<?PACKET_COMMAND, 0:32, Cmd/binary>>}, State};
+
 %% 用户进程关闭，则关闭通道
 websocket_info({'DOWN', _, process, HostPid, Reason}, State = #state{uuid = UUID, host_pid = HostPid}) ->
     lager:debug("[ws_channel] uuid: ~p, channel will close because host exited with reason: ~p", [UUID, Reason]),