From a8a7fd0299b257c21bfc554582138a469c52e2ef Mon Sep 17 00:00:00 2001
From: Ery Lee <ery.lee@gmail.com>
Date: Mon, 9 Mar 2015 14:05:40 +0800
Subject: [PATCH] TABLE -> METRIC_TAB

---
 apps/emqtt/src/emqtt_metrics.erl | 44 +++++++++++++++++---------------
 1 file changed, 24 insertions(+), 20 deletions(-)

diff --git a/apps/emqtt/src/emqtt_metrics.erl b/apps/emqtt/src/emqtt_metrics.erl
index 5efa99dd1..07f18c02c 100644
--- a/apps/emqtt/src/emqtt_metrics.erl
+++ b/apps/emqtt/src/emqtt_metrics.erl
@@ -34,29 +34,32 @@
 
 -define(SERVER, ?MODULE).
 
--define(TABLE, ?MODULE).
+-define(METRIC_TAB, ?MODULE).
 
-%% ------------------------------------------------------------------
 %% API Function Exports
-%% ------------------------------------------------------------------
-
 -export([start_link/1]).
 
 -export([all/0, value/1,
          inc/1, inc/2,
          dec/1, dec/2]).
 
-%% ------------------------------------------------------------------
 %% gen_server Function Exports
-%% ------------------------------------------------------------------
 -export([init/1, handle_call/3, handle_cast/2, handle_info/2,
          terminate/2, code_change/3]).
 
 -record(state, {pub_interval, tick_timer}).
 
-%% ------------------------------------------------------------------
-%% API Function Definitions
-%% ------------------------------------------------------------------
+%%%=============================================================================
+%%% API
+%%%=============================================================================
+
+%%------------------------------------------------------------------------------
+%% @doc
+%% Start emqtt metrics.
+%%
+%% @end
+%%------------------------------------------------------------------------------
+-spec start_link([tuple()]) -> {ok, pid()} | ignore | {error, term()}.
 start_link(Options) ->
     gen_server:start_link({local, ?SERVER}, ?MODULE, [Options], []).
 
@@ -75,7 +78,7 @@ all() ->
                         {ok, Count} -> maps:put(Metric, Count+Val, Map);
                         error -> maps:put(Metric, Val, Map)
                     end
-            end, #{}, ?TABLE)).
+            end, #{}, ?METRIC_TAB)).
 
 %%------------------------------------------------------------------------------
 %% @doc
@@ -85,7 +88,7 @@ all() ->
 %%------------------------------------------------------------------------------
 -spec value(atom()) -> non_neg_integer().
 value(Metric) ->
-    lists:sum(ets:select(?TABLE, [{{{Metric, '_'}, '$1'}, [], ['$1']}])).
+    lists:sum(ets:select(?METRIC_TAB, [{{{Metric, '_'}, '$1'}, [], ['$1']}])).
 
 %%------------------------------------------------------------------------------
 %% @doc
@@ -105,7 +108,7 @@ inc(Metric) ->
 %%------------------------------------------------------------------------------
 -spec inc(atom(), pos_integer()) -> pos_integer().
 inc(Metric, Val) ->
-    ets:update_counter(?TABLE, key(Metric), {2, Val}).
+    ets:update_counter(?METRIC_TAB, key(Metric), {2, Val}).
 
 %%------------------------------------------------------------------------------
 %% @doc
@@ -126,7 +129,7 @@ dec(Metric) ->
 -spec dec(atom(), pos_integer()) -> integer().
 dec(Metric, Val) ->
     %TODO: ok?
-    ets:update_counter(?TABLE, key(Metric), {2, -Val}).
+    ets:update_counter(?METRIC_TAB, key(Metric), {2, -Val}).
 
 %%------------------------------------------------------------------------------
 %% @doc
@@ -141,15 +144,16 @@ key(Metric) ->
 %% ------------------------------------------------------------------
 %% gen_server Function Definitions
 %% ------------------------------------------------------------------
+
 init(Options) ->
     random:seed(now()),
     Topics = ?SYSTOP_BYTES ++ ?SYSTOP_PACKETS ++ ?SYSTOP_MESSAGES,
-    % $SYS Topics for metrics
-    [{atomic, _} = emqtt_pubsub:create(systop(Topic)) || Topic <- Topics],
     % Create metrics table
-    ets:new(?TABLE, [set, public, named_table, {write_concurrency, true}]),
+    ets:new(?METRIC_TAB, [set, public, named_table, {write_concurrency, true}]),
     % Init metrics
     [new_metric(Topic) || Topic <- Topics],
+    % $SYS Topics for metrics
+    [{atomic, _} = emqtt_pubsub:create(systop(Topic)) || Topic <- Topics],
     PubInterval = proplists:get_value(pub_interval, Options, 60),
     {ok, tick(random:uniform(PubInterval), #state{pub_interval = PubInterval}), hibernate}.
 
@@ -173,9 +177,9 @@ terminate(_Reason, _State) ->
 code_change(_OldVsn, State, _Extra) ->
     {ok, State}.
 
-%% ------------------------------------------------------------------
-%% Internal Function Definitions
-%% ------------------------------------------------------------------
+%%%=============================================================================
+%%% Internal functions
+%%%=============================================================================
 
 systop(Name) when is_atom(Name) ->
     list_to_binary(lists:concat(["$SYS/brokers/", node(), "/", Name])).
@@ -185,7 +189,7 @@ publish(Topic, Payload) ->
 
 new_metric(Name) ->
     Schedulers = lists:seq(1, erlang:system_info(schedulers)),
-    [ets:insert(?TABLE, {{Name, I}, 0}) || I <- Schedulers].
+    [ets:insert(?METRIC_TAB, {{Name, I}, 0}) || I <- Schedulers].
 
 tick(State = #state{pub_interval = PubInterval}) ->
     tick(PubInterval, State).