fix mqtt

src/endpoint/endpoint_mqtt.erl

@@ -1,4 +1,3 @@
-
 %%%-------------------------------------------------------------------
 %%% @author aresei
 %%% @copyright (C) 2023, <COMPANY>
@@ -10,30 +9,27 @@
 -module(endpoint_mqtt).
 
 -include("endpoint.hrl").
--behaviour(gen_server).
+-behaviour(gen_statem).
 
 %% API
 -export([start_link/2]).
 
-%% gen_server callbacks
+%% gen_statem callbacks
--export([init/1, handle_call/3, handle_cast/2, handle_info/2, terminate/2, code_change/3]).
+-export([callback_mode/0, init/1, handle_event/4, terminate/3, code_change/4]).
 
 %% 消息重发间隔
 -define(RETRY_INTERVAL, 15000).
 
--define(DISCONNECTED, disconnected).
--define(CONNECTED, connected).
-
 -record(state, {
     endpoint :: #endpoint{},
     buffer :: endpoint_buffer:buffer(),
     conn_pid :: undefined | pid(),
     %% 待确认的数据, #{PacketId :: integer() => Id :: integer()}
-    inflight = #{},
+    inflight = #{}
-
-    status = disconnected
 }).
 
+-type mqtt_state() :: disconnected | connecting | connected.
+
 %%%===================================================================
 %%% API
 %%%===================================================================
@@ -41,69 +37,67 @@
 %% @doc Creates a gen_statem process which calls Module:init/1 to
 %% initialize. To ensure a synchronized start-up procedure, this
 %% function does not return until Module:init/1 has returned.
+-spec start_link(LocalName :: atom(), Endpoint :: #endpoint{}) ->
+    {ok, pid()} | ignore | {error, term()}.
 start_link(LocalName, Endpoint = #endpoint{}) when is_atom(LocalName) ->
-    gen_server:start_link({local, LocalName}, ?MODULE, [Endpoint], []).
+    gen_statem:start_link({local, LocalName}, ?MODULE, [Endpoint], []).
 
 %%%===================================================================
 %%% gen_statem callbacks
 %%%===================================================================
 
+-spec callback_mode() -> handle_event_function.
+callback_mode() ->
+    handle_event_function.
+
 %% @private
 %% @doc Whenever a gen_statem is started using gen_statem:start/[3,4] or
 %% gen_statem:start_link/[3,4], this function is called by the new
 %% process to initialize.
+-spec init(term()) -> gen_statem:init_result(mqtt_state(), #state{}).
 init([Endpoint = #endpoint{matcher = Matcher}]) ->
     ok = iot_log:set_metadata(),
     erlang:process_flag(trap_exit, true),
-    endpoint_subscription:subscribe(Matcher, self()),
+    ok = endpoint_subscription:subscribe(Matcher, self()),
-
-    %% 创建转发器, 避免阻塞当前进程的创建，因此采用了延时初始化的机制
-    erlang:start_timer(0, self(), create_postman),
-    %% 初始化存储
     Buffer = endpoint_buffer:new(Endpoint, 10),
+    {ok, disconnected, #state{endpoint = Endpoint, buffer = Buffer}, [{next_event, internal, connect}]}.
 
-    {ok, #state{endpoint = Endpoint, buffer = Buffer, status = ?DISCONNECTED}}.
+-spec handle_event(gen_statem:event_type(), term(), mqtt_state(), #state{}) ->
-
+    gen_statem:event_handler_result(mqtt_state(), #state{}).
-%% @private
+handle_event({call, From}, get_stat, _StateName, State = #state{buffer = Buffer}) ->
-%% @doc Handling call messages
--spec(handle_call(Request :: term(), From :: {pid(), Tag :: term()},
-    State :: #state{}) ->
-    {reply, Reply :: term(), NewState :: #state{}} |
-    {reply, Reply :: term(), NewState :: #state{}, timeout() | hibernate} |
-    {noreply, NewState :: #state{}} |
-    {noreply, NewState :: #state{}, timeout() | hibernate} |
-    {stop, Reason :: term(), Reply :: term(), NewState :: #state{}} |
-    {stop, Reason :: term(), NewState :: #state{}}).
-handle_call(get_stat, _From, State = #state{buffer = Buffer}) ->
     Stat = endpoint_buffer:stat(Buffer),
-    {reply, {ok, Stat}, State}.
+    {keep_state, State, [{reply, From, {ok, Stat}}]};
-
+handle_event(cast, {forward, Metric}, _StateName, State = #state{buffer = Buffer}) ->
-%% @private
-%% @doc Handling cast messages
--spec(handle_cast(Request :: term(), State :: #state{}) ->
-    {noreply, NewState :: #state{}} |
-    {noreply, NewState :: #state{}, timeout() | hibernate} |
-    {stop, Reason :: term(), NewState :: #state{}}).
-handle_cast({forward, Metric}, State = #state{buffer = Buffer}) ->
     NBuffer = endpoint_buffer:append(Metric, Buffer),
-    {noreply, State#state{buffer = NBuffer}};
+    {keep_state, State#state{buffer = NBuffer}};
-handle_cast({reload, NEndpoint = #endpoint{matcher = NMatcher}}, State = #state{endpoint = #endpoint{matcher = Matcher}, conn_pid = ConnPid}) ->
+handle_event(cast, cleanup, _StateName, #state{buffer = Buffer}) ->
+    endpoint_buffer:cleanup(Buffer),
+    keep_state_and_data;
+handle_event(cast, {reload, NEndpoint = #endpoint{matcher = NMatcher}}, StateName,
+             State = #state{endpoint = #endpoint{matcher = Matcher}, conn_pid = ConnPid}) ->
     ensure_subscription(Matcher, NMatcher),
     stop_mqtt_conn(ConnPid),
-    schedule_reconnect(),
+    NState = State#state{endpoint = NEndpoint, conn_pid = undefined, inflight = #{}},
-    {noreply, State#state{endpoint = NEndpoint, conn_pid = undefined, inflight = #{}, status = ?DISCONNECTED}};
+    {next_state, connecting, NState, maybe_connect_actions(StateName)};
-handle_cast(cleanup, State = #state{buffer = Buffer}) ->
-    endpoint_buffer:cleanup(Buffer),
-    {noreply, State}.
 
-%% @private
+handle_event(internal, connect, disconnected, State) ->
-%% @doc Handling all non call/cast messages
+    {next_state, connecting, State, [{next_event, internal, do_connect}]};
--spec(handle_info(Info :: timeout() | term(), State :: #state{}) ->
+handle_event(internal, connect, connecting, State) ->
-    {noreply, NewState :: #state{}} |
+    {keep_state, State, [{next_event, internal, do_connect}]};
-    {noreply, NewState :: #state{}, timeout() | hibernate} |
+handle_event(internal, connect, connected, State) ->
-    {stop, Reason :: term(), NewState :: #state{}}).
+    {keep_state, State};
-handle_info({timeout, _, create_postman}, State = #state{buffer = Buffer, status = ?DISCONNECTED,
+handle_event(internal, do_connect, connecting,
-    endpoint = #endpoint{title = Title, config = #mqtt_endpoint{host = Host, port = Port, username = Username, password = Password, client_id = ClientId}}}) ->
+             State = #state{buffer = Buffer,
+                            endpoint = #endpoint{
+                                title = Title,
+                                config = #mqtt_endpoint{
+                                    host = Host,
+                                    port = Port,
+                                    username = Username,
+                                    password = Password,
+                                    client_id = ClientId
+                                }
+                            }}) ->
     logger:debug("[endpoint_mqtt] endpoint: ~ts, create postman", [Title]),
     Opts = [
         {owner, self()},
@@ -119,84 +113,88 @@ handle_info({timeout, _, create_postman}, State = #state{buffer = Buffer, status
         {proto_ver, v5},
         {retry_interval, 5000}
     ],
-
+    case connect_mqtt(Opts) of
-    try
+        {ok, ConnPid} ->
-        {ok, ConnPid} = emqtt:start_link(Opts),
+            logger:debug("[endpoint_mqtt] connect success, pid: ~p", [ConnPid]),
-        logger:debug("[endpoint_mqtt] start connect, options: ~p", [Opts]),
+            NBuffer = endpoint_buffer:trigger_n(Buffer),
-        case emqtt:connect(ConnPid, 5000) of
+            {next_state, connected, State#state{conn_pid = ConnPid, buffer = NBuffer}};
-            {ok, _} ->
+        {error, Reason} ->
-                logger:debug("[endpoint_mqtt] connect success, pid: ~p", [ConnPid]),
+            logger:warning("[endpoint_mqtt] connect get error: ~p", [Reason]),
-                NBuffer = endpoint_buffer:trigger_n(Buffer),
+            {next_state, disconnected, State#state{conn_pid = undefined, inflight = #{}},
-                {noreply, State#state{conn_pid = ConnPid, buffer = NBuffer, status = ?CONNECTED}};
+             [{state_timeout, ?RETRY_INTERVAL, connect}]}
-            {error, Reason} ->
-                logger:warning("[endpoint_mqtt] connect get error: ~p", [Reason]),
-                erlang:start_timer(?RETRY_INTERVAL, self(), create_postman),
-                {noreply, State}
-        end
-    catch _:Error->
-        logger:warning("[endpoint_mqtt] connect get error: ~p", [Error]),
-        erlang:start_timer(?RETRY_INTERVAL, self(), create_postman),
-        {noreply, State}
     end;
 
-%% 离线时，忽略数据发送逻辑
+handle_event(state_timeout, connect, disconnected, State) ->
-handle_info({next_data, _Id, _Tuple}, State = #state{status = ?DISCONNECTED}) ->
+    {next_state, connecting, State, [{next_event, internal, do_connect}]};
-    {noreply, State};
+handle_event(state_timeout, connect, connecting, State) ->
-%% 发送数据到mqtt服务器
+    {keep_state, State, [{next_event, internal, do_connect}]};
-handle_info({next_data, Id, Metric}, State = #state{status = ?CONNECTED, conn_pid = ConnPid, buffer = Buffer, inflight = InFlight,
-    endpoint = #endpoint{config = #mqtt_endpoint{topic = Topic, qos = Qos}}}) ->
 
+%% 离线或连接中时，忽略数据发送逻辑
+handle_event(info, {next_data, _Id, _Tuple}, disconnected, State) ->
+    {keep_state, State};
+handle_event(info, {next_data, _Id, _Tuple}, connecting, State) ->
+    {keep_state, State};
+%% 发送数据到mqtt服务器
+handle_event(info, {next_data, Id, Metric}, connected,
+             State = #state{
+                 conn_pid = ConnPid,
+                 buffer = Buffer,
+                 inflight = InFlight,
+                 endpoint = #endpoint{config = #mqtt_endpoint{topic = Topic, qos = Qos}}
+             }) ->
     logger:debug("[endpoint_mqtt] will publish topic: ~p, metric: ~p, qos: ~p", [Topic, Metric, Qos]),
     case emqtt:publish(ConnPid, Topic, #{}, Metric, [{qos, Qos}, {retain, true}]) of
         ok ->
             NBuffer = endpoint_buffer:ack(Id, Buffer),
-            {noreply, State#state{buffer = NBuffer}};
+            {keep_state, State#state{buffer = NBuffer}};
         {ok, PacketId} ->
-            {noreply, State#state{inflight = maps:put(PacketId, Id, InFlight)}};
+            {keep_state, State#state{inflight = maps:put(PacketId, Id, InFlight)}};
         {error, Reason} ->
             logger:warning("[endpoint_mqtt] send message to topic: ~p, get error: ~p", [Topic, Reason]),
             stop_mqtt_conn(ConnPid),
-            schedule_reconnect(),
+            {next_state, disconnected, State#state{conn_pid = undefined, inflight = #{}},
-            {noreply, State#state{conn_pid = undefined, inflight = #{}, status = ?DISCONNECTED}}
+             [{state_timeout, ?RETRY_INTERVAL, connect}]}
     end;
 
-	handle_info({disconnected, ReasonCode, Properties}, State = #state{status = ?CONNECTED}) ->
+handle_event(info, {disconnected, ReasonCode, Properties}, connected, State = #state{conn_pid = ConnPid}) ->
     logger:debug("[endpoint_mqtt] Recv a DISONNECT packet - ReasonCode: ~p, Properties: ~p", [ReasonCode, Properties]),
-    schedule_reconnect(),
+    stop_mqtt_conn(ConnPid),
-    {noreply, State#state{conn_pid = undefined, inflight = #{}, status = ?DISCONNECTED}};
+    {next_state, disconnected, State#state{conn_pid = undefined, inflight = #{}},
-
+     [{state_timeout, ?RETRY_INTERVAL, connect}]};
-handle_info({publish, Message = #{packet_id := _PacketId, payload := Payload}}, State = #state{status = ?CONNECTED}) ->
+handle_event(info, {publish, Message = #{packet_id := _PacketId, payload := Payload}}, connected, State) ->
     logger:debug("[endpoint_mqtt] Recv a publish packet: ~p, payload: ~p", [Message, Payload]),
-    {noreply, State};
+    {keep_state, State};
-
+handle_event(info, {puback, #{packet_id := PacketId}}, connected,
-%% 收到确认的消息
+             State = #state{inflight = Inflight, buffer = Buffer}) ->
-handle_info({puback, #{packet_id := PacketId}}, State = #state{status = ?CONNECTED, inflight = Inflight, buffer = Buffer}) ->
     case maps:take(PacketId, Inflight) of
         {Id, RestInflight} ->
             NBuffer = endpoint_buffer:ack(Id, Buffer),
-            {noreply, State#state{buffer = NBuffer, inflight = RestInflight}};
+            {keep_state, State#state{buffer = NBuffer, inflight = RestInflight}};
         error ->
-            {noreply, State}
+            {keep_state, State}
     end;
 
 %% postman进程挂掉时，重新建立新的
-handle_info({'EXIT', ConnPid, Reason}, State = #state{endpoint = #endpoint{title = Title}, conn_pid = ConnPid}) ->
+handle_event(info, {'EXIT', ConnPid, Reason}, _StateName,
+             State = #state{endpoint = #endpoint{title = Title}, conn_pid = ConnPid}) ->
     logger:warning("[endpoint_mqtt] endpoint: ~p, conn pid exit with reason: ~p", [Title, Reason]),
-    schedule_reconnect(),
+    {next_state, disconnected, State#state{conn_pid = undefined, inflight = #{}},
-    {noreply, State#state{conn_pid = undefined, inflight = #{}, status = ?DISCONNECTED}};
+     [{state_timeout, ?RETRY_INTERVAL, connect}]};
 
-handle_info(Info, State = #state{status = Status}) ->
+handle_event(info, Info, StateName, State) ->
-    logger:warning("[endpoint_mqtt] unknown message: ~p, status: ~p", [Info, Status]),
+    logger:warning("[endpoint_mqtt] unknown message: ~p, status: ~p", [Info, StateName]),
-    {noreply, State}.
+    {keep_state, State};
+handle_event(EventType, EventContent, StateName, State) ->
+    logger:warning("[endpoint_mqtt] unknown event: ~p, content: ~p, status: ~p", [EventType, EventContent, StateName]),
+    {keep_state, State}.
 
 %% @private
-%% @doc This function is called by a gen_server when it is about to
+%% @doc This function is called by a gen_statem when it is about to
 %% terminate. It should be the opposite of Module:init/1 and do any
-%% necessary cleaning up. When it returns, the gen_server terminates
+%% necessary cleaning up. When it returns, the gen_statem terminates
 %% with Reason. The return value is ignored.
--spec(terminate(Reason :: (normal | shutdown | {shutdown, term()} | term()),
+-spec terminate(Reason :: term(), StateName :: mqtt_state(), State :: #state{}) -> term().
-    State :: #state{}) -> term()).
+terminate(Reason, _StateName, #state{endpoint = #endpoint{title = Title}, buffer = Buffer, conn_pid = ConnPid}) ->
-terminate(Reason, #state{endpoint = #endpoint{title = Title}, buffer = Buffer, conn_pid = ConnPid}) ->
     logger:debug("[endpoint_mqtt] endpoint: ~p, terminate with reason: ~p", [Title, Reason]),
     stop_mqtt_conn(ConnPid),
     endpoint_buffer:cleanup(Buffer),
@@ -204,11 +202,13 @@ terminate(Reason, #state{endpoint = #endpoint{title = Title}, buffer = Buffer, c
 
 %% @private
 %% @doc Convert process state when code is changed
--spec(code_change(OldVsn :: term() | {down, term()}, State :: #state{},
+-spec code_change(OldVsn :: term() | {down, term()},
-    Extra :: term()) ->
+                  StateName :: mqtt_state(),
-    {ok, NewState :: #state{}} | {error, Reason :: term()}).
+                  State :: #state{},
-code_change(_OldVsn, State = #state{}, _Extra) ->
+                  Extra :: term()) ->
-    {ok, State}.
+    {ok, StateName :: mqtt_state(), NewState :: #state{}} | {error, term()}.
+code_change(_OldVsn, StateName, State = #state{}, _Extra) ->
+    {ok, StateName, State}.
 
 %%%===================================================================
 %%% Internal functions
@@ -221,9 +221,30 @@ ensure_subscription(Matcher, NMatcher) ->
     ok = endpoint_subscription:unsubscribe(Matcher, self()),
     endpoint_subscription:subscribe(NMatcher, self()).
 
--spec schedule_reconnect() -> reference().
+-spec maybe_connect_actions(mqtt_state()) -> [gen_statem:action()].
-schedule_reconnect() ->
+maybe_connect_actions(connected) ->
-    erlang:start_timer(?RETRY_INTERVAL, self(), create_postman).
+    [{next_event, internal, do_connect}];
+maybe_connect_actions(connecting) ->
+    [{next_event, internal, do_connect}];
+maybe_connect_actions(disconnected) ->
+    [{next_event, internal, do_connect}].
+
+-spec connect_mqtt(list()) -> {ok, pid()} | {error, term()}.
+connect_mqtt(Opts) ->
+    try
+        {ok, ConnPid} = emqtt:start_link(Opts),
+        logger:debug("[endpoint_mqtt] start connect, options: ~p", [Opts]),
+        case emqtt:connect(ConnPid, 5000) of
+            {ok, _} ->
+                {ok, ConnPid};
+            {error, Reason} ->
+                stop_mqtt_conn(ConnPid),
+                {error, Reason}
+        end
+    catch
+        _:Error ->
+            {error, Error}
+    end.
 
 -spec stop_mqtt_conn(undefined | pid()) -> ok.
 stop_mqtt_conn(undefined) ->