Implement synchronous produce->consume cycle, for testing.

[beam_stats.git] / src / beam_stats_consumer.erl

diff --git a/src/beam_stats_consumer.erl b/src/beam_stats_consumer.erl
index eb8cbb7..3e46042 100644 (file)
--- a/src/beam_stats_consumer.erl
+++ b/src/beam_stats_consumer.erl
@@ -1,7 +1,6 @@
 -module(beam_stats_consumer).
 
 -include("include/beam_stats.hrl").
--include(        "beam_stats.hrl").
 
 -behaviour(gen_server).
 
@@ -12,6 +11,8 @@
 %% Public API
 -export(
     [ add/2
+    , consume_sync/2
+    , consume_async/2
     ]).
 
 %% Internal API
@@ -49,7 +50,9 @@
 %% Internal data
 %% ============================================================================
 
--define(SIGNAL_CONSUMPTION , beam_stats_consumption_signal).
+-define(FLUSH         , flush).
+-define(CONSUME_SYNC  , consume_sync).
+-define(CONSUME_ASYNC , consume_async).
 
 -record(state,
     { consumer_module      :: module()
@@ -58,6 +61,9 @@
     , beam_stats_queue     :: queue()
     }).
 
+-type state() ::
+    #state{}.
+
 %% ============================================================================
 %%  Public API
 %% ============================================================================
@@ -67,6 +73,17 @@
 add(ConsumerModule, ConsumerOptions) ->
     beam_stats_sup_consumers:start_child(ConsumerModule, ConsumerOptions).
 
+-spec consume_sync(pid(), beam_stats:t()) ->
+    {}.
+consume_sync(PID, #beam_stats{}=BEAMStats) ->
+    {} = gen_server:call(PID, {?CONSUME_SYNC, BEAMStats}).
+
+-spec consume_async(pid(), beam_stats:t()) ->
+    {}.
+consume_async(PID, #beam_stats{}=BEAMStats) ->
+    ok = gen_server:cast(PID, {?CONSUME_ASYNC, BEAMStats}),
+    {}.
+
 %% ============================================================================
 %%  Internal API
 %% ============================================================================
@@ -81,9 +98,6 @@ start_link(ConsumerModule, ConsumerOptions) ->
 %%  gen_server callbacks (unused)
 %% ============================================================================
 
-handle_call(_Request, _From, State) ->
-    ?METHOD_SHOULD_NOT_BE_USED(handle_call, State).
-
 code_change(_OldVsn, State, _Extra) ->
     {ok, State}.
 
@@ -100,44 +114,65 @@ init([ConsumerModule, ConsumerOptions]) ->
         , beam_stats_queue     = queue:new()
         },
     ok = beam_stats_producer:subscribe(self()),
-    ok = schedule_first_consumption(),
+    ok = schedule_first_flush(),
     {ok, State}.
 
 terminate(_Reason, _State) ->
     ok = beam_stats_producer:unsubscribe(self()).
 
-handle_cast(#beam_stats{}=BEAMStats, #state{beam_stats_queue=Q1}=State) ->
-    Q2 = queue:in(BEAMStats, Q1),
-    {noreply, State#state{beam_stats_queue = Q2}}.
+handle_call({?CONSUME_SYNC, #beam_stats{}=BEAMStats}, _, #state{}=State1) ->
+    State2 = consume_one(BEAMStats, State1),
+    {reply, {}, State2}.
 
-handle_info(
-    ?SIGNAL_CONSUMPTION,
-    #state
-    { consumer_module      = ConsumerModule
-    , consumer_state       = ConsumerState
-    , consumption_interval = ConsumptionInterval
-    , beam_stats_queue     = Q
-    }=State1
-) ->
-    State2 = State1#state
-        { consumer_state   = ConsumerModule:consume(Q, ConsumerState)
-        , beam_stats_queue = queue:new()
-        },
-    ok = schedule_next_consumption(ConsumptionInterval),
+handle_cast({?CONSUME_ASYNC, #beam_stats{}=BEAMStats}, #state{}=State1) ->
+    State2 = enqueue(BEAMStats, State1),
+    {noreply, State2}.
+
+handle_info(?FLUSH, #state{consumption_interval=ConsumptionInterval}=State1) ->
+    State2 = consume_all_queued(State1),
+    ok = schedule_next_flush(ConsumptionInterval),
     {noreply, State2}.
 
 %% ============================================================================
 %%  Internal
 %% ============================================================================
 
--spec schedule_first_consumption() ->
+-spec consume_one(beam_stats:t(), state()) ->
+    state().
+consume_one(#beam_stats{}=BEAMStats, #state{}=State1) ->
+    Q = queue:in(BEAMStats, queue:new()),
+    consume(Q, State1).
+
+-spec consume_all_queued(state()) ->
+    state().
+consume_all_queued(#state{beam_stats_queue=Q}=State1) ->
+    State2 = consume(Q, State1),
+    State2#state{beam_stats_queue = queue:new()}.
+
+-spec consume(queue(), state()) ->
+    state().
+consume(
+    Q,
+    #state
+    { consumer_module  = ConsumerModule
+    , consumer_state   = ConsumerState
+    }=State
+) ->
+    State#state{consumer_state = ConsumerModule:consume(Q, ConsumerState)}.
+
+-spec enqueue(beam_stats:t(), state()) ->
+    state().
+enqueue(#beam_stats{}=BEAMStats, #state{beam_stats_queue=Q}=State) ->
+    State#state{beam_stats_queue = queue:in(BEAMStats, Q)}.
+
+-spec schedule_first_flush() ->
     ok.
-schedule_first_consumption() ->
-    _ = self() ! ?SIGNAL_CONSUMPTION,
+schedule_first_flush() ->
+    _ = self() ! ?FLUSH,
     ok.
 
--spec schedule_next_consumption(non_neg_integer()) ->
+-spec schedule_next_flush(non_neg_integer()) ->
     ok.
-schedule_next_consumption(Time) ->
-    _ = erlang:send_after(Time, self(), ?SIGNAL_CONSUMPTION),
+schedule_next_flush(Time) ->
+    _ = erlang:send_after(Time, self(), ?FLUSH),
     ok.