fix subscription

apps/efka/src/efka_subscription.erl

@@ -14,7 +14,7 @@
 %% API
 -export([start_link/0]).
 -export([subscribe/2, publish/4, publish/2, response/2]).
--export([match_components/2, match_topic/2, is_valid_components/1, of_components/1]).
+-export([match_components/2, is_valid_components/1, of_components/1]).
 
 %% gen_server callbacks
 -export([init/1, handle_call/3, handle_cast/2, handle_info/2, terminate/2, code_change/3]).
@@ -25,7 +25,12 @@
 -record(subscriber, {
     topic :: binary(),
     subscriber_pid :: pid(),
-    components = []
+    components = [],
+    %% 优先级
+    %% 1. 完全匹配的topic优先级别最高
+    %% 2. 带 * 的订阅
+    %% 3. 带 + 的订阅
+    order :: integer()
 }).
 
 -record(state, {
@@ -97,23 +102,40 @@ handle_cast({subscribe, Topic, SubscriberPid}, State = #state{subscribers = Subs
     Components = of_components(Topic),
     case is_valid_components(Components) of
         true ->
-            Sub = #subscriber{topic = Topic, subscriber_pid = SubscriberPid, components = Components},
-            {noreply, State#state{subscribers = [Sub|Subscribers]}};
+            Sub = #subscriber{topic = Topic, subscriber_pid = SubscriberPid, components = Components, order = order_num(Components)},
+            %% 建立到SubscriberPid的monitor，进程退出需要清理订阅
+            erlang:monitor(process, SubscriberPid),
+
+            {noreply, State#state{subscribers = Subscribers ++ [Sub]}};
         false ->
             {noreply, State}
     end;
 
 %% 不需要响应的推送
 handle_cast({publish, Topic, Content}, State = #state{subscribers = Subscribers}) ->
-    AccPids = dispatch(Subscribers, <<"">>, Topic, Content),
-    lager:debug("[efka_subscription] topic: ~p, content: ~p, match subscribers: ~p", [Topic, Content, AccPids]),
+    %% 不需要回复的消息体采用广播的信息
+    MatchedSubscribers = match_subscribers(Subscribers, Topic),
+    lists:foreach(fun(#subscriber{subscriber_pid = SubscriberPid}) ->
+        erlang:send(SubscriberPid, {topic_broadcast, Content})
+                  end, MatchedSubscribers),
+
+    lager:debug("[efka_subscription] topic: ~p, content: ~p, match subscribers: ~p", [Topic, Content, MatchedSubscribers]),
     {noreply, State};
 
 %% 需要响应的推送
 handle_cast({publish, PacketId, Topic, Content, CallbackFun}, State = #state{subscribers = Subscribers, callbacks = Callbacks}) when PacketId > 0 ->
     ShaUUID = sha_uuid(),
-    AccPids = dispatch(Subscribers, ShaUUID, Topic, Content),
-    lager:debug("[efka_subscription] topic: ~p, content: ~p, match subscribers: ~p", [Topic, Content, AccPids]),
+
+    %% 基于优先级
+    MatchedSubscribers = match_subscribers(Subscribers, Topic),
+    SortedSubscribers = lists:sort(fun(#subscriber{order = Order0}, #subscriber{order = Order1}) -> Order0 < Order1 end, MatchedSubscribers),
+    case SortedSubscribers of
+        [] ->
+            ok;
+        [S = #subscriber{subscriber_pid = SubscriberPid} | _] ->
+            lager:debug("[efka_subscription] topic_sink topic: ~p, content: ~p, match subscriber: ~p", [Topic, Content, S]),
+            erlang:send(SubscriberPid, {topic_sink, Content})
+    end,
 
     {noreply, State#state{callbacks = maps:put(ShaUUID, CallbackFun, Callbacks)}};
 
@@ -133,7 +155,13 @@ handle_cast({response, ShaUUID, Response}, State = #state{callbacks = Callbacks}
     {noreply, NewState :: #state{}} |
     {noreply, NewState :: #state{}, timeout() | hibernate} |
     {stop, Reason :: term(), NewState :: #state{}}).
-handle_info(_Info, State = #state{}) ->
+handle_info({'DOWN', _Ref, process, SubscriberPid, Reason}, State = #state{subscribers = Subscribers}) ->
+    lager:debug("[efka_subscription] subscriber: ~p, down with reason: ~p", [SubscriberPid, Reason]),
+    NSubscribers = lists:filter(fun(#subscriber{subscriber_pid = Pid0}) -> SubscriberPid /= Pid0 end, Subscribers),
+    {noreply, State#state{subscribers = NSubscribers}};
+
+handle_info(Info, State = #state{}) ->
+    lager:debug("[efka_subscription] get unknown info: ~p", [Info]),
     {noreply, State}.
 
 %% @private
@@ -171,12 +199,25 @@ dispatch(Subscribers, ShaUUID, Topic, Content) when is_list(Subscribers), is_bin
         end
                 end, [], Subscribers).
 
-match_topic(Topic0, Topic1) ->
-    match_components(of_components(Topic0), of_components(Topic1)).
+%% 查找满足条件订阅者
+-spec match_subscribers(Subscribers :: [#subscriber{}], Topic :: binary()) -> [#subscriber{}].
+match_subscribers(Subscribers, Topic) when is_list(Subscribers), is_binary(Topic) ->
+    Components = of_components(Topic),
+    lists:foldl(fun(S = #subscriber{components = Components0, subscriber_pid = Pid0}, Acc) ->
+        case match_components(Components0, Components) andalso not contain_channel(Pid0, Acc) of
+            true ->
+                [S|Acc];
+            false ->
+                Acc
+        end
+                end, [], Subscribers).
+
+-spec contain_channel(Pid :: pid(), Subscribers :: list()) -> boolean().
+contain_channel(Pid, Subscribers) when is_pid(Pid), is_list(Subscribers) ->
+    lists:search(fun(#subscriber{subscriber_pid = Pid0}) -> Pid == Pid0 end, Subscribers) /= false.
 
 %% 开始对比订阅的topic和发布的topic的Components信息
 %% *表示单级匹配，+表示多级匹配；+只能出现一次，并且只能在末尾
-
 -spec match_components(list(), list()) -> boolean().
 match_components(A, B) when is_list(A), is_list(B) ->
     match_components(A, B, false).
@@ -204,10 +245,19 @@ is_valid_components([<<$*>>|T]) ->
 is_valid_components([_|T]) ->
     is_valid_components(T).
 
+-spec order_num(Components :: list()) -> integer().
+order_num([]) ->
+    1;
+order_num([<<$*>>|_]) ->
+    2;
+order_num([<<$+>>|_]) ->
+    3;
+order_num([_|Tail]) ->
+    order_num(Tail).
+
 %% 生产唯一的uuid
 -spec sha_uuid() -> binary().
 sha_uuid() ->
     Salt = crypto:strong_rand_bytes(32),
     Str = string:lowercase(binary:encode_hex(crypto:hash(sha256, Salt))),
-    binary:part(Str, 1, 32).
-
+    binary:part(Str, 1, 32).