Move the aging code to router

src/emqttd_pubsub_helper.erl

@@ -1,5 +1,5 @@
 %%%-----------------------------------------------------------------------------
-%%% Copyright (c) 2012-2015 eMQTT.IO, All Rights Reserved.
+%%% Copyright (c) 2012-2016 eMQTT.IO, All Rights Reserved.
 %%%
 %%% Permission is hereby granted, free of charge, to any person obtaining a copy
 %%% of this software and associated documentation files (the "Software"), to deal
@@ -19,176 +19,66 @@
 %%% OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 %%% SOFTWARE.
 %%%-----------------------------------------------------------------------------
-%%% @doc PubSub Route Aging Helper
+%%% @doc PubSub Helper.
 %%%
 %%% @author Feng Lee <feng@emqtt.io>
 %%%-----------------------------------------------------------------------------
 -module(emqttd_pubsub_helper).
 
--behaviour(gen_server2).
+-behaviour(gen_server).
 
 -include("emqttd.hrl").
 
 -include("emqttd_internal.hrl").
 
 %% API Function Exports
--export([start_link/2, aging/1]).
+-export([start_link/1]).
 
 %% gen_server Function Exports
 -export([init/1, handle_call/3, handle_cast/2, handle_info/2,
          terminate/2, code_change/3]).
 
--ifdef(TEST).
--compile(export_all).
--endif.
-
--record(aging, {topics, time, tref}).
-
--record(state, {aging :: #aging{}, statsfun}).
+-record(state, {statsfun}).
 
 -define(SERVER, ?MODULE).
 
--define(ROUTER, emqttd_router).
-
-%%%=============================================================================
-%%% API
-%%%=============================================================================
-
-%%------------------------------------------------------------------------------
-%% @doc Start pubsub helper.
-%% @end
-%%------------------------------------------------------------------------------
--spec start_link(fun(), list(tuple())) -> {ok, pid()} | ignore | {error, any()}.
-start_link(StatsFun, Opts) ->
-    gen_server2:start_link({local, ?SERVER}, ?MODULE, [StatsFun, Opts], []).
-
-%%------------------------------------------------------------------------------
-%% @doc Aging topics
-%% @end
-%%------------------------------------------------------------------------------
--spec aging(list(binary())) -> ok.
-aging(Topics) ->
-    gen_server2:cast(?SERVER, {aging, Topics}).
+%% @doc Start PubSub Helper.
+-spec start_link(fun()) -> {ok, pid()} | ignore | {error, any()}.
+start_link(StatsFun) ->
+    gen_server:start_link({local, ?SERVER}, ?MODULE, [StatsFun], []).
 
 %%%=============================================================================
 %%% gen_server callbacks
 %%%=============================================================================
 
-init([StatsFun, Opts]) ->
+init([StatsFun]) ->
     mnesia:subscribe(system),
-
-    AgingSecs = proplists:get_value(route_aging, Opts, 5),
-
-    %% Aging Timer
-    {ok, AgingTref} = start_tick(AgingSecs div 2),
-
-    {ok, #state{aging = #aging{topics = dict:new(),
-                               time   = AgingSecs,
-                               tref   = AgingTref},
-               statsfun = StatsFun}}.
-
-start_tick(Secs) ->
-    timer:send_interval(timer:seconds(Secs), {clean, aged}).
+    {ok, #state{statsfun = StatsFun}}.
 
 handle_call(Req, _From, State) ->
     ?UNEXPECTED_REQ(Req, State).
 
-handle_cast({aging, Topics}, State = #state{aging = Aging}) ->
-    #aging{topics = Dict} = Aging,
-    TS = emqttd_util:now_to_secs(),
-    Dict1 =
-    lists:foldl(fun(Topic, Acc) ->
-                    case dict:find(Topic, Acc) of
-                        {ok, _} -> Acc;
-                        error   -> dict:store(Topic, TS, Acc)
-                    end
-                end, Dict, Topics),
-    {noreply, State#state{aging = Aging#aging{topics = Dict1}}};
-
 handle_cast(Msg, State) ->
     ?UNEXPECTED_MSG(Msg, State).
 
-handle_info({clean, aged}, State = #state{aging = Aging}) ->
-
-    #aging{topics = Dict, time = Time} = Aging,
-
-    ByTime  = emqttd_util:now_to_secs() - Time,
-
-    Dict1 = try_clean(ByTime, dict:to_list(Dict)),
-
-    NewAging = Aging#aging{topics = dict:from_list(Dict1)},
-
-    noreply(State#state{aging = NewAging});
-
 handle_info({mnesia_system_event, {mnesia_down, Node}}, State) ->
-    %% mnesia master?
+    %% TODO: mnesia master?
     Pattern = #mqtt_topic{_ = '_', node = Node},
     F = fun() ->
             [mnesia:delete_object(topic, R, write) ||
                 R <- mnesia:match_object(topic, Pattern, write)]
         end,
-    mnesia:async_dirty(F),
-    noreply(State);
+    mnesia:transaction(F), noreply(State);
 
 handle_info(Info, State) ->
     ?UNEXPECTED_INFO(Info, State).
 
-terminate(_Reason, #state{aging = #aging{tref = TRef}}) ->
-    timer:cancel(TRef).
+terminate(_Reason, _State) ->
+    mnesia:unsubscribe(system).
 
 code_change(_OldVsn, State, _Extra) ->
     {ok, State}.
 
-%%%=============================================================================
-%%% Internal Functions
-%%%=============================================================================
-
 noreply(State = #state{statsfun = StatsFun}) ->
-    StatsFun(topic),
-    {noreply, State, hibernate}.
-
-try_clean(ByTime, List) ->
-    try_clean(ByTime, List, []).
-
-try_clean(_ByTime, [], Acc) ->
-    Acc;
-
-try_clean(ByTime, [{Topic, TS} | Left], Acc) ->
-    case ?ROUTER:has_route(Topic) of
-        false ->
-            try_clean2(ByTime, {Topic, TS}, Left, Acc);
-        true  ->
-            try_clean(ByTime, Left, Acc)
-    end.
-
-try_clean2(ByTime, {Topic, TS}, Left, Acc) when TS > ByTime ->
-    try_clean(ByTime, Left, [{Topic, TS}|Acc]);
-
-try_clean2(ByTime, {Topic, _TS}, Left, Acc) ->
-    TopicR = #mqtt_topic{topic = Topic, node = node()},
-    mnesia:transaction(fun try_remove_topic/1, [TopicR]),
-    try_clean(ByTime, Left, Acc).
-
-try_remove_topic(TopicR = #mqtt_topic{topic = Topic}) ->
-    %% Lock topic first
-    case mnesia:wread({topic, Topic}) of
-        [] -> ok;
-        [TopicR] ->
-            if_no_route(Topic, fun() ->
-                %% Remove topic and trie
-                mnesia:delete_object(topic, TopicR, write),
-                emqttd_trie:delete(Topic)
-            end);
-        _More ->
-            if_no_route(Topic, fun() ->
-                %% Remove topic
-                mnesia:delete_object(topic, TopicR, write)
-            end)
-    end.
-        
-if_no_route(Topic, Fun) ->
-    case ?ROUTER:has_route(Topic) of
-        true -> ok;
-        false -> Fun()
-    end.
+    StatsFun(topic), {noreply, State}.