From 09197d37752a586c48988d96c83ff87f65117cf4 Mon Sep 17 00:00:00 2001
From: zhouzb <zhouzb@emqx.io>
Date: Wed, 22 Apr 2020 15:08:14 +0800
Subject: [PATCH] Delete expired client

---
 src/emqx_flapping.erl        | 13 ++++++++++++-
 test/emqx_flapping_SUITE.erl | 14 +++++++++++++-
 2 files changed, 25 insertions(+), 2 deletions(-)

diff --git a/src/emqx_flapping.erl b/src/emqx_flapping.erl
index 2256ef015..36323d90f 100644
--- a/src/emqx_flapping.erl
+++ b/src/emqx_flapping.erl
@@ -109,7 +109,7 @@ init([]) ->
                                          {read_concurrency, true},
                                          {write_concurrency, true}
                                         ]),
-    {ok, #{}, hibernate}.
+    {ok, ensure_timer(#{}), hibernate}.
 
 handle_call(Req, _From, State) ->
     ?LOG(error, "Unexpected call: ~p", [Req]),
@@ -142,6 +142,12 @@ handle_cast(Msg, State) ->
     ?LOG(error, "Unexpected cast: ~p", [Msg]),
     {noreply, State}.
 
+handle_info({timeout, TRef, expired_detecting}, State = #{expired_timer := TRef}) ->
+    Timestamp = erlang:system_time(millisecond) - maps:get(duration, get_policy()),
+    MatchSpec = [{{'_', '_', '_', '$1', '_'},[{'<', '$1', Timestamp}], [true]}],
+    ets:select_delete(?FLAPPING_TAB, MatchSpec),
+    {noreply, ensure_timer(State), hibernate};
+
 handle_info(Info, State) ->
     ?LOG(error, "Unexpected info: ~p", [Info]),
     {noreply, State}.
@@ -151,3 +157,8 @@ terminate(_Reason, _State) ->
 
 code_change(_OldVsn, State, _Extra) ->
     {ok, State}.
+
+ensure_timer(State) ->
+    Timeout = maps:get(duration, get_policy()),
+    TRef = emqx_misc:start_timer(Timeout, expired_detecting),
+    State#{expired_timer => TRef}.
\ No newline at end of file
diff --git a/test/emqx_flapping_SUITE.erl b/test/emqx_flapping_SUITE.erl
index 223fd5d7e..dcd552385 100644
--- a/test/emqx_flapping_SUITE.erl
+++ b/test/emqx_flapping_SUITE.erl
@@ -19,6 +19,8 @@
 -compile(export_all).
 -compile(nowarn_export_all).
 
+-include_lib("eunit/include/eunit.hrl").
+
 all() -> emqx_ct:all(?MODULE).
 
 init_per_suite(Config) ->
@@ -50,7 +52,7 @@ t_detect_check(_) ->
     false = emqx_flapping:detect(ClientInfo),
     false = emqx_banned:check(ClientInfo),
     true = emqx_flapping:detect(ClientInfo),
-    timer:sleep(100),
+    timer:sleep(50),
     true = emqx_banned:check(ClientInfo),
     timer:sleep(3000),
     false = emqx_banned:check(ClientInfo),
@@ -61,3 +63,13 @@ t_detect_check(_) ->
     Pid ! test,
     ok = emqx_flapping:stop().
 
+t_expired_detecting(_) ->
+    ClientInfo = #{zone => external,
+                   clientid => <<"clientid">>,
+                   peerhost => {127,0,0,1}},
+    false = emqx_flapping:detect(ClientInfo),
+    ?assertEqual(true, lists:any(fun({flapping, <<"clientid">>, _, _, _}) -> true;
+                                    (_) -> false end, ets:tab2list(emqx_flapping))),
+    timer:sleep(200),
+    ?assertEqual(true, lists:all(fun({flapping, <<"clientid">>, _, _, _}) -> false;
+                                    (_) -> true end, ets:tab2list(emqx_flapping))).
\ No newline at end of file