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-rw-r--r--src/rabbit_event.erl71
1 files changed, 44 insertions, 27 deletions
diff --git a/src/rabbit_event.erl b/src/rabbit_event.erl
index 0f00537a..2b236531 100644
--- a/src/rabbit_event.erl
+++ b/src/rabbit_event.erl
@@ -34,9 +34,9 @@
-include("rabbit.hrl").
-export([start_link/0]).
--export([init_stats_timer/0, ensure_stats_timer/3, stop_stats_timer/2]).
--export([ensure_stats_timer_after/2, reset_stats_timer_after/1]).
--export([stats_level/1]).
+-export([init_stats_timer/0, ensure_stats_timer/2, stop_stats_timer/1]).
+-export([reset_stats_timer/1]).
+-export([stats_level/1, if_enabled/2]).
-export([notify/2]).
%%----------------------------------------------------------------------------
@@ -71,11 +71,11 @@
-spec(start_link/0 :: () -> rabbit_types:ok_pid_or_error()).
-spec(init_stats_timer/0 :: () -> state()).
--spec(ensure_stats_timer/3 :: (state(), timer_fun(), timer_fun()) -> state()).
--spec(stop_stats_timer/2 :: (state(), timer_fun()) -> state()).
--spec(ensure_stats_timer_after/2 :: (state(), timer_fun()) -> state()).
--spec(reset_stats_timer_after/1 :: (state()) -> state()).
+-spec(ensure_stats_timer/2 :: (state(), timer_fun()) -> state()).
+-spec(stop_stats_timer/1 :: (state()) -> state()).
+-spec(reset_stats_timer/1 :: (state()) -> state()).
-spec(stats_level/1 :: (state()) -> level()).
+-spec(if_enabled/2 :: (state(), timer_fun()) -> 'ok').
-spec(notify/2 :: (event_type(), event_props()) -> 'ok').
-endif.
@@ -85,44 +85,61 @@
start_link() ->
gen_event:start_link({local, ?MODULE}).
+%% The idea is, for each stat-emitting object:
+%%
+%% On startup:
+%% Timer = init_stats_timer()
+%% notify(created event)
+%% if_enabled(internal_emit_stats) - so we immediately send something
+%%
+%% On wakeup:
+%% ensure_stats_timer(Timer, emit_stats)
+%% (Note we can't emit stats immediately, the timer may have fired 1ms ago.)
+%%
+%% emit_stats:
+%% if_enabled(internal_emit_stats)
+%% reset_stats_timer(Timer) - just bookkeeping
+%%
+%% Pre-hibernation:
+%% if_enabled(internal_emit_stats)
+%% stop_stats_timer(Timer)
+%%
+%% internal_emit_stats:
+%% notify(stats)
+
init_stats_timer() ->
{ok, StatsLevel} = application:get_env(rabbit, collect_statistics),
#state{level = StatsLevel, timer = undefined}.
-ensure_stats_timer(State = #state{level = none}, _NowFun, _TimerFun) ->
+ensure_stats_timer(State = #state{level = none}, _Fun) ->
State;
-ensure_stats_timer(State = #state{timer = undefined}, NowFun, TimerFun) ->
- NowFun(),
- {ok, TRef} = timer:apply_interval(?STATS_INTERVAL,
- erlang, apply, [TimerFun, []]),
+ensure_stats_timer(State = #state{timer = undefined}, Fun) ->
+ {ok, TRef} = timer:apply_after(?STATS_INTERVAL,
+ erlang, apply, [Fun, []]),
State#state{timer = TRef};
-ensure_stats_timer(State, _NowFun, _TimerFun) ->
+ensure_stats_timer(State, _Fun) ->
State.
-stop_stats_timer(State = #state{level = none}, _NowFun) ->
+stop_stats_timer(State = #state{level = none}) ->
State;
-stop_stats_timer(State = #state{timer = undefined}, _NowFun) ->
+stop_stats_timer(State = #state{timer = undefined}) ->
State;
-stop_stats_timer(State = #state{timer = TRef}, NowFun) ->
+stop_stats_timer(State = #state{timer = TRef}) ->
{ok, cancel} = timer:cancel(TRef),
- NowFun(),
State#state{timer = undefined}.
-ensure_stats_timer_after(State = #state{level = none}, _TimerFun) ->
- State;
-ensure_stats_timer_after(State = #state{timer = undefined}, TimerFun) ->
- {ok, TRef} = timer:apply_after(?STATS_INTERVAL,
- erlang, apply, [TimerFun, []]),
- State#state{timer = TRef};
-ensure_stats_timer_after(State, _TimerFun) ->
- State.
-
-reset_stats_timer_after(State) ->
+reset_stats_timer(State) ->
State#state{timer = undefined}.
stats_level(#state{level = Level}) ->
Level.
+if_enabled(#state{level = none}, _Fun) ->
+ ok;
+if_enabled(_State, Fun) ->
+ Fun(),
+ ok.
+
notify(Type, Props) ->
try
%% TODO: switch to os:timestamp() when we drop support for