add subscri

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anlicheng 2025-04-29 00:44:59 +08:00
parent 4f2fd35cb4
commit 4489bdd79c

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@ -0,0 +1,170 @@
%%%-------------------------------------------------------------------
%%% @author anlicheng
%%% @copyright (C) 2025, <COMPANY>
%%% @doc
%%%
%%% @end
%%% Created : 28. 4 2025 23:50
%%%-------------------------------------------------------------------
-module(efka_subscription).
-author("anlicheng").
-behaviour(gen_server).
%% API
-export([start_link/0]).
-export([match_components/2, match_topic/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]).
-define(SERVER, ?MODULE).
%%
-record(subscriber, {
topic :: binary(),
subscriber_pid :: pid(),
components = []
}).
-record(state, {
subscribers = []
}).
%%%===================================================================
%%% API
%%%===================================================================
subscribe(Topic, SubscriberPid) when is_binary(Topic), is_pid(SubscriberPid) ->
gen_server:cast(?SERVER, {subscribe, Topic, SubscriberPid}).
publish(Topic, Content) when is_binary(Topic), is_binary(Content) ->
gen_server:cast(?SERVER, {publish, Topic, Content}).
%% @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(_Request, _From, State = #state{}) ->
{reply, ok, State}.
%% @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{}}).
%% SubscriberPid只能订阅同一个topic一次
handle_cast({subscribe, Topic, SubscriberPid}, State = #state{subscribers = Subscribers}) ->
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]}};
false ->
{noreply, State}
end;
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]),
{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(_Info, State = #state{}) ->
{noreply, State}.
%% @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
%%%===================================================================
-spec dispatch(Subscribers :: list(), Topic :: binary(), Content :: binary()) -> [pid()].
dispatch(Subscribers, Topic, Content) when is_list(Subscribers), is_binary(Topic), is_binary(Content) ->
Components = of_components(Topic),
lists:foldl(fun(#subscriber{components = Components0, subscriber_pid = SubscriberPid}, AccPids) ->
case match_components(Components0, Components) andalso not lists:member(SubscriberPid, AccPids) of
true ->
erlang:send(SubscriberPid, {xyz, Content}),
[SubscriberPid|AccPids];
false ->
AccPids
end
end, [], Subscribers).
match_topic(Topic0, Topic1) ->
match_components(of_components(Topic0), of_components(Topic1)).
%% topic和发布的topic的Components信息
%% *++
-spec match_components(list(), list()) -> boolean().
match_components([<<$+>>], [_|_]) ->
true;
match_components([], []) ->
true;
match_components([<<$*>>|T0], [_|T1]) ->
match_components(T0, T1);
match_components([C0|T0], [C0|T1]) ->
match_components(T0, T1);
match_components(_, _) ->
false.
-spec of_components(Topic :: binary()) -> [binary()].
of_components(Topic) when is_binary(Topic) ->
binary:split(Topic, <<$/>>, [global]).
is_valid_components([]) ->
true;
is_valid_components([<<$+>>|T]) ->
length(T) =:= 0;
is_valid_components([<<$*>>|T]) ->
is_valid_components(T);
is_valid_components([_|T]) ->
is_valid_components(T).