change oc_stat_stdout_handler to gen_event implementation

Author: hauleth

src/oc_stat_config.erl

@@ -0,0 +1,16 @@
+-module(oc_stat_stdout_handler).
+
+-behaviour(gen_event).
+
+-export([init/1,
+         handle_call/2,
+         handle_event/2]).
+
+init(Opts) -> {ok, Opts}.
+
+handle_call(_Msg, State) -> {ok, ok, State}.
+
+handle_event({stats, ViewData}, State) ->
+    [io:format("~s: ~p~n", [Name, Data]) || #{name := Name,
+                                              data := Data} <- ViewData],
+    {ok, State}.

src/oc_stat_exporter_stdout.erl

@@ -13,7 +13,7 @@
 %% limitations under the License.
 %%%------------------------------------------------------------------------
 
--module(oc_reporter_stdout).
+-module(oc_trace_stdout_handler).
 
 -behaviour(gen_event).
 

src/oc_stat_stdout_handler.erl

@@ -23,13 +23,11 @@
          handle_call/2,
          handle_event/2]).
 
-init(_) ->
-    {ok, application:get_env(opencensus, tab_reporter, #{})}.
+init(Tab) -> {ok, Tab}.
 
 handle_call(_Msg, State) -> {ok, ok, State}.
 
-handle_event({spans, Spans}, Opts) ->
-    Tid = maps:get(tid, Opts),
-    ets:insert(Tid, Spans),
+handle_event({spans, Spans}, Tab) ->
+    true = ets:insert(Tab, Spans),
 
-    {ok, Opts}.
+    {ok, Tab}.

src/oc_reporter_stdout.erl src/oc_trace_stdout_handler.erlsrc/oc_reporter_stdout.erl renamed to src/oc_trace_stdout_handler.erl

@@ -28,10 +28,9 @@ end_per_suite(_Config) ->
 
 init_per_testcase(_, Config) ->
     Tab = ets:new(reporter_tab, [public, {keypos, #span.span_id}]),
-    Reporters = [{oc_tab_reporter, []}],
+    Reporters = [{oc_tab_reporter, Tab}],
     application:set_env(opencensus, trace, [{interval, 1},
                                             {handlers, Reporters}]),
-    application:set_env(opencensus, tab_reporter, #{tid => Tab}),
     {ok, _} = application:ensure_all_started(opencensus),
     [{tid, Tab} | Config].
 

test/oc_tab_reporter.erl

@@ -26,9 +26,9 @@ end_per_suite(_Config) ->
 
 init_per_testcase(_, Config) ->
     Tab = ets:new(reporter_tab, [public, {keypos, #span.span_id}]),
+    Reporters = [{oc_tab_reporter, Tab}],
     application:set_env(opencensus, trace, [{interval, 1},
-                                            {handlers, [{oc_tab_reporter, []}]}]),
-    application:set_env(opencensus, tab_reporter, #{tid => Tab}),
+                                            {handlers, Reporters}]),
     application:set_env(opencensus, sampler, {oc_sampler_always, []}),
     {ok, _} = application:ensure_all_started(opencensus),
     [{tid, Tab} | Config].