diff --git a/apps/iot/src/http_handlers/event_stream_handler.erl b/apps/iot/src/http_handlers/event_stream_handler.erl new file mode 100644 index 0000000..85efc84 --- /dev/null +++ b/apps/iot/src/http_handlers/event_stream_handler.erl @@ -0,0 +1,46 @@ +%%%------------------------------------------------------------------- +%%% @author anlicheng +%%% @copyright (C) 2025, +%%% @doc +%%% +%%% @end +%%% Created : 08. 5月 2025 13:00 +%%%------------------------------------------------------------------- +-module(event_stream_handler). +-author("anlicheng"). + +%% API +-export([init/2]). + +init(Req0, Opts) -> + Method = binary_to_list(cowboy_req:method(Req0)), + Path = binary_to_list(cowboy_req:path(Req0)), + GetParams0 = cowboy_req:parse_qs(Req0), + GetParams = maps:from_list(GetParams0), + + #{<<"task_id">> := TaskId0} = GetParams, + TaskId = binary_to_integer(TaskId0), + + lager:debug("method: ~p, path: ~p, get: ~p", [Method, Path, GetParams]), + Req1 = cowboy_req:stream_reply(200, #{ + <<"content-type">> => <<"text/event-stream">>, + <<"cache-control">> => <<"no-cache">> + }, Req0), + + ok = iot_event_stream_observer:add_listener(self(), TaskId), + receiver_events(TaskId, Req1), + + {ok, Req1, Opts}. + +receiver_events(TaskId, Req) -> + receive + {stream_data, TaskId, Type, Stream} -> + Data = jiffy:encode(#{<<"type">> => Type, <<"stream">> => Stream}, [force_utf8]), + Body = iolist_to_binary([<<"event: message\n">>, <<"data: ", Data/binary, "\n">>, <<"\n">>]), + ok = cowboy_req:stream_body(Body, nofin, Req), + + receiver_events(TaskId, Req); + {stream_close, TaskId} -> + CloseFrame = iolist_to_binary([<<"event: close\n">>, <<"data: bye\n">>, <<"\n">>]), + ok = cowboy_req:stream_body(CloseFrame, fin, Req) + end. \ No newline at end of file diff --git a/apps/iot/src/iot_app.erl b/apps/iot/src/iot_app.erl index ffe015d..3534e95 100644 --- a/apps/iot/src/iot_app.erl +++ b/apps/iot/src/iot_app.erl @@ -49,7 +49,8 @@ start_http_server() -> {'_', [ {"/host/[...]", http_protocol, [host_handler]}, {"/container/[...]", http_protocol, [container_handler]}, - {"/device/[...]", http_protocol, [device_handler]} + {"/device/[...]", http_protocol, [device_handler]}, + {"/event_stream", event_stream_handler, []} ]} ]), diff --git a/apps/iot/src/iot_event_stream_observer.erl b/apps/iot/src/iot_event_stream_observer.erl new file mode 100644 index 0000000..45bc14d --- /dev/null +++ b/apps/iot/src/iot_event_stream_observer.erl @@ -0,0 +1,128 @@ +%%%------------------------------------------------------------------- +%%% @author anlicheng +%%% @copyright (C) 2025, +%%% @doc +%%% +%%% @end +%%% Created : 26. 9月 2025 12:19 +%%%------------------------------------------------------------------- +-module(iot_event_stream_observer). +-author("anlicheng"). + +-behaviour(gen_server). + +%% API +-export([start_link/0]). +-export([add_listener/2, stream_data/3, stream_close/1]). + +%% gen_server callbacks +-export([init/1, handle_call/3, handle_cast/2, handle_info/2, terminate/2, code_change/3]). + +-define(SERVER, ?MODULE). + +-record(state, { + listeners = #{} +}). + +%%%=================================================================== +%%% API +%%%=================================================================== + +-spec add_listener(ListenerPid :: pid(), TaskId :: integer()) -> ok. +add_listener(ListenerPid, TaskId) when is_pid(ListenerPid), is_integer(TaskId) -> + gen_server:call(?SERVER, {add_listener, ListenerPid, TaskId}). + +-spec stream_data(TaskId :: integer(), Type :: binary(), Stream :: binary()) -> no_return(). +stream_data(TaskId, Type, Stream) when is_integer(TaskId), is_binary(Type), is_binary(Stream) -> + gen_server:cast(?SERVER, {stream_data, TaskId, Type, Stream}). + +-spec stream_close(TaskId :: integer()) -> no_return(). +stream_close(TaskId) when is_integer(TaskId) -> + gen_server:cast(?SERVER, {stream_close, TaskId}). + +%% @doc Spawns the server and registers the local name (unique) +-spec(start_link() -> + {ok, Pid :: pid()} | ignore | {error, Reason :: term()}). +start_link() -> + gen_server:start_link({local, ?SERVER}, ?MODULE, [], []). + +%%%=================================================================== +%%% gen_server callbacks +%%%=================================================================== + +%% @private +%% @doc Initializes the server +-spec(init(Args :: term()) -> + {ok, State :: #state{}} | {ok, State :: #state{}, timeout() | hibernate} | + {stop, Reason :: term()} | ignore). +init([]) -> + {ok, #state{}}. + +%% @private +%% @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({add_listener, ListenerPid, TaskId}, _From, State = #state{listeners = Listeners}) -> + erlang:monitor(process, ListenerPid), + {reply, ok, State#state{listeners = maps:put(TaskId, ListenerPid, Listeners)}}. + +%% @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({stream_data, TaskId, Type, Stream}, State = #state{listeners = Listeners}) -> + case maps:find(TaskId, Listeners) of + error -> + ok; + {ok, ListenerPid} -> + is_process_alive(ListenerPid) andalso ListenerPid ! {stream_data, TaskId, Type, Stream} + end, + {noreply, State}; +handle_cast({stream_close, TaskId}, State = #state{listeners = Listeners}) -> + case maps:find(TaskId, Listeners) of + error -> + ok; + {ok, ListenerPid} -> + is_process_alive(ListenerPid) andalso ListenerPid ! {stream_close, TaskId} + end, + {noreply, State}. + +%% @private +%% @doc Handling all non call/cast messages +-spec(handle_info(Info :: timeout() | term(), State :: #state{}) -> + {noreply, NewState :: #state{}} | + {noreply, NewState :: #state{}, timeout() | hibernate} | + {stop, Reason :: term(), NewState :: #state{}}). +handle_info({'DOWN', _Ref, process, Pid, _Reason}, State = #state{listeners = Listeners}) -> + NListeners = maps:filter(fun(_, ListenerPid) -> ListenerPid /= Pid end, Listeners), + {noreply, State#state{listeners = NListeners}}. + +%% @private +%% @doc This function is called by a gen_server 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 +%% with Reason. The return value is ignored. +-spec(terminate(Reason :: (normal | shutdown | {shutdown, term()} | term()), + State :: #state{}) -> term()). +terminate(_Reason, _State = #state{}) -> + ok. + +%% @private +%% @doc Convert process state when code is changed +-spec(code_change(OldVsn :: term() | {down, term()}, State :: #state{}, + Extra :: term()) -> + {ok, NewState :: #state{}} | {error, Reason :: term()}). +code_change(_OldVsn, State = #state{}, _Extra) -> + {ok, State}. + +%%%=================================================================== +%%% Internal functions +%%%=================================================================== diff --git a/apps/iot/src/iot_sup.erl b/apps/iot/src/iot_sup.erl index 9c3b9ff..56c6e86 100644 --- a/apps/iot/src/iot_sup.erl +++ b/apps/iot/src/iot_sup.erl @@ -28,6 +28,15 @@ init([]) -> SupFlags = #{strategy => one_for_one, intensity => 10, period => 36}, Specs = [ + #{ + id => 'iot_event_stream_observer', + start => {'iot_event_stream_observer', start_link, []}, + restart => permanent, + shutdown => 2000, + type => worker, + modules => ['iot_event_stream_observer'] + }, + #{ id => 'iot_name_server', start => {'iot_name_server', start_link, []}, diff --git a/apps/iot/src/tcp/tcp_channel.erl b/apps/iot/src/tcp/tcp_channel.erl index 722d359..be26552 100644 --- a/apps/iot/src/tcp/tcp_channel.erl +++ b/apps/iot/src/tcp/tcp_channel.erl @@ -139,8 +139,11 @@ handle_info({tcp, Socket, <>}, State = #state{sock iot_host:handle(HostPid, {data, Data}); #event{} = Event -> iot_host:handle(HostPid, {event, Event}); + #task_event_stream{task_id = TaskId, type = <<"close">>, stream = <<>>} -> + iot_event_stream_observer:stream_close(TaskId); #task_event_stream{task_id = TaskId, type = Type, stream = Stream} -> - lager:debug("[tcp_channel] get task_id: ~p, type: ~ts, stream: ~ts", [TaskId, Type, Stream]) + lager:debug("[tcp_channel] get task_id: ~p, type: ~ts, stream: ~ts", [TaskId, Type, Stream]), + iot_event_stream_observer:stream_data(TaskId, Type, Stream) end, {noreply, State};