解决了mqtt的连接问题

apps/iot/src/iot_mqtt_connection.erl

@@ -9,13 +9,15 @@
 -behaviour(gen_statem).
 
 %% API
--export([start_link/2, publish_status/1, publish_msg/2]).
+-export([start_link/3, publish_status/1, publish_msg/4]).
-
 %% gen_statem callbacks
 -export([init/1, callback_mode/0, disconnected/3, connected/3, terminate/3, code_change/4]).
 
+-define(CONNECT_ACTION(T), {state_timeout, T, start_connect}).
+
 -record(state, {
     parent_pid  :: pid(),
+    opts = [],
     conn_pid    :: pid() | undefined,
     retry       :: non_neg_integer(),
     topics      :: list(),
@@ -25,20 +27,18 @@
 %%%===================================================================
 %%% API
 %%%===================================================================
-
+-spec start_link(pid(), list(), list()) ->
--spec start_link(pid(), list()) ->
     {ok, pid()} | ignore | {error, term()}.
-start_link(ParentPid, Topics)
+start_link(ParentPid, Opts, Topics) when is_pid(ParentPid), is_list(Topics) ->
-    when is_pid(ParentPid), is_list(Topics) ->
+    gen_statem:start_link(?MODULE, [ParentPid, Opts, Topics], []).
-    gen_statem:start_link(?MODULE, [ParentPid, Topics], []).
 
 -spec publish_status(pid()) -> map().
 publish_status(Pid) when is_pid(Pid) ->
     gen_statem:call(Pid, status).
 
--spec publish_msg(pid(), any()) -> ok.
+-spec publish_msg(Pid :: pid(), Topic :: binary(), Payload :: binary(), Qos :: integer()) -> ok.
-publish_msg(Pid, Msg) when is_pid(Pid) ->
+publish_msg(Pid, Topic, Payload, Qos) when is_pid(Pid), is_binary(Topic), is_binary(Payload), is_integer(Qos) ->
-    gen_statem:cast(Pid, {publish, Msg}).
+    gen_statem:cast(Pid, {publish, Topic, Payload, Qos}).
 
 %%%===================================================================
 %%% gen_statem callbacks
@@ -47,35 +47,52 @@ publish_msg(Pid, Msg) when is_pid(Pid) ->
 callback_mode() ->
     state_functions.
 
-init([ParentPid, Topics]) ->
+init([ParentPid, Opts0, Topics]) ->
-    self() ! start_connect,
+    erlang:process_flag(trap_exit, true),
-    {ok, disconnected, #state{parent_pid = ParentPid, topics = Topics, retry = 0, conn_pid = undefined, queue = queue:new()}}.
+
+    DefaultOpts = [
+        {owner, self()},
+        {tcp_opts, []},
+        {auto_ack, true},
+        {proto_ver, v3}
+    ],
+    Opts = Opts0 ++ DefaultOpts,
+
+    {ok, disconnected, #state{parent_pid = ParentPid, opts = Opts, topics = Topics, retry = 0, conn_pid = undefined, queue = queue:new()}, ?CONNECT_ACTION(0)}.
 
 %%%===================================================================
 %%% disconnected state
 %%%===================================================================
 
-disconnected(info, start_connect, State = #state{retry = Retry, topics = Topics}) ->
+disconnected(state_timeout, start_connect, State = #state{retry = Retry, opts = Opts, topics = Topics}) ->
-    Opts = iot_config:emqt_opts(<<"host-subscriber">>),
-    lager:debug("[mqtt] connecting, opts=~p", [Opts]),
     case emqtt:start_link(Opts) of
         {ok, ConnPid} ->
-            {ok, _} = emqtt:connect(ConnPid),
+            case emqtt:connect(ConnPid) of
+                {ok, _} ->
                     maybe_subscribe(ConnPid, Topics),
                     NState = flush_queue(ConnPid, State#state{conn_pid = ConnPid, retry = 0}),
                     {next_state, connected, NState};
+                {error, _Reason} ->
+                    %% 连接错误发生的时候，emqtt进程一定会挂掉，在进程错误的时候处理; 否则连接错误和服务端关闭需要2个分支来处理
+                    %% 这里保存进程id是为了，错误时候的模式匹配
+                    {keep_state, State#state{conn_pid = ConnPid}}
+            end;
         _ ->
-            {keep_state, State#state{retry = Retry + 1}, [{timeout, start_connect, 5000}]}
+            {keep_state, State#state{retry = Retry + 1}, ?CONNECT_ACTION(5000)}
     end;
 
 %% 掉线期间 publish → 入队
-disconnected(cast, {publish, Msg}, State = #state{queue = Q}) ->
+disconnected(cast, {publish, Topic, Payload, Qos}, State = #state{queue = Q}) ->
-    {keep_state, State#state{queue = enqueue(Q, Msg)}};
+    {keep_state, State#state{queue = enqueue(Q, {Topic, Payload, Qos})}};
 
 %% status
 disconnected({call, From}, status, State) ->
     reply_status(disconnected, From, State);
 
+%% 处理mqtt socket断开的问题
+disconnected(info, {'EXIT', ConnPid, _Reason}, State = #state{conn_pid = ConnPid}) ->
+    {keep_state, State, ?CONNECT_ACTION(5000)};
+
 %% 兜底
 disconnected(_Type, _Event, State) ->
     {keep_state, State}.
@@ -85,14 +102,17 @@ disconnected(_Type, _Event, State) ->
 %%%===================================================================
 
 %% 正常 publish
-connected(cast, {publish, Msg}, State = #state{conn_pid = ConnPid}) ->
+connected(cast, {publish, Topic, Payload, Qos}, State = #state{conn_pid = ConnPid}) ->
-    do_publish(ConnPid, Msg),
+    do_publish(ConnPid, Topic, Payload, Qos),
     {keep_state, State};
 
 %% MQTT 断线
-connected(info, {disconnect, ReasonCode, _Props}, State) ->
+connected(info, {disconnect, _ReasonCode, _Props}, State) ->
-    lager:warning("[mqtt] disconnected, reason=~p", [ReasonCode]),
+    {next_state, disconnected, State#state{conn_pid = undefined}, ?CONNECT_ACTION(5000)};
-    {next_state, disconnected, State#state{conn_pid = undefined}, [{timeout, start_connect, 5000}]};
+
+%% 处理mqtt socket断开的问题
+connected(info, {'EXIT', ConnPid, _Reason}, State = #state{conn_pid = ConnPid}) ->
+    {next_state, disconnected, State#state{conn_pid = undefined}, ?CONNECT_ACTION(5000)};
 
 %% 收到订阅消息
 connected(info, {publish, #{topic := Topic, payload := Payload, qos := Qos}}, State = #state{parent_pid = ParentPid}) ->
@@ -100,8 +120,8 @@ connected(info, {publish, #{topic := Topic, payload := Payload, qos := Qos}}, St
     {keep_state, State};
 
 %% puback
-connected(info, {puback, Packet}, _State) ->
+connected(info, {puback, Ack}, #state{parent_pid = ParentPid}) ->
-    lager:debug("[mqtt] puback ~p", [Packet]),
+    ParentPid ! {mqtt_puback, Ack},
     keep_state_and_data;
 
 %% status
@@ -122,27 +142,24 @@ enqueue(Q, Msg) ->
         true ->
             queue:in(Msg, Q);
         false ->
-            lager:warning("[mqtt] queue full, drop msg"),
             Q
     end.
 
 -spec flush_queue(pid(), #state{}) -> #state{}.
 flush_queue(ConnPid, State = #state{queue = Q}) ->
     lists:foreach(
-        fun(Msg) -> do_publish(ConnPid, Msg) end,
+        fun({Topic, Payload, Qos}) -> do_publish(ConnPid, Topic, Payload, Qos) end,
         queue:to_list(Q)
     ),
     State#state{queue = queue:new()}.
 
--spec do_publish(pid(), any()) -> ok.
+do_publish(ConnPid, Topic, Payload, Qos) ->
-do_publish(ConnPid, Msg) ->
     try
-        emqtt:publish(ConnPid, Msg),
+        emqtt:publish(ConnPid, Topic, Payload, Qos),
         ok
     catch
-        _:Err ->
+        _ ->
-            lager:error("[mqtt] publish failed ~p, requeue", [Err]),
+            gen_statem:cast(self(), {publish, Topic, Payload, Qos}),
-            gen_statem:cast(self(), {publish, Msg}),
             ok
     end.