add metrics:update_or_create/3 .

Author: benoitc

src/metrics.erl

@@ -13,6 +13,7 @@
 %% API
 -export([new/2]).
 -export([update/1, update/2]).
+-export([update_or_create/3]).
 -export([backend/0, backend/1]).
 
 -export([start_link/0]).
@@ -61,6 +62,12 @@ update(Name) ->
 update(Name, Probe) ->
   metrics_mod:update(Name, Probe).
 
+%% @doc update a metric and create it if it doesn't exists
+-spec update_or_create(list(), probe(), metric()) -> ok | any().
+update_or_create(Name, Probe, Type) ->
+  metrics_mod:update_or_create(Name, Probe, Type).
+
+
 %% @doc retrieve the current backend name
 -spec backend() -> atom().
 backend() -> gen_server:call(?MODULE, get_backend).
@@ -163,9 +170,11 @@ build_metrics_mod(Mod, Config) when is_atom(Mod), is_map(Config) ->
     [?Q("(Type, Name) -> _@Mod@:new(Type, Name, _@Config@)")]),
   Update = erl_syntax:function(merl:term('update'),
     [?Q("(Name, Probe) -> _@Mod@:update(Name, Probe, _@Config@)")]),
+  UpdateOrCreate = erl_syntax:function(merl:term('update_or_create'),
+    [?Q("(Name, Probe, Type) -> _@Mod@:update_or_create(Name, Probe, Type, _@Config@)")]),
   Module = ?Q("-module('metrics_mod')."),
-  Exported = ?Q("-export(['new'/2, 'update'/2])."),
-  Functions = [ ?Q("'@_F'() -> [].") || F <- [New, Update]],
+  Exported = ?Q("-export(['new'/2, 'update'/2, 'update_or_create'/3])."),
+  Functions = [ ?Q("'@_F'() -> [].") || F <- [New, Update, UpdateOrCreate]],
   Forms = lists:flatten([Module, Exported, Functions]),
   merl:compile_and_load(Forms, [verbose]),
   ok.

src/metrics_exometer.erl

@@ -11,7 +11,7 @@
 -author("Benoit Chesneau").
 
 %% API
--export([new/3, update/3]).
+-export([new/3, update/3, update_or_create/4]).
 
 
 -spec new(atom(), any(), map()) -> ok | {error, metric_exists | unsupported_type}.
@@ -30,3 +30,8 @@ new(_, _, _) ->
 
 update(Name, {c, I}, _Config) when is_integer(I) -> exometer:update(Name, I);
 update(Name, Val, _Config) -> exometer:update(Name, Val).
+
+update_or_create(Name, {c, I}, Type, _Config) when is_integer(I) ->
+  exometer:update_or_create(Name, I, Type, []);
+update_or_create(Name, Val, Type, _Config) ->
+  exometer:update_or_create(Name, Val, Type, []).

src/metrics_folsom.erl

@@ -11,7 +11,7 @@
 -author("Benoit Chesneau").
 
 %% API
--export([new/3, update/3]).
+-export([new/3, update/3, update_or_create/4]).
 
 -spec new(atom(), any(), map()) -> ok | {error, term()}.
 new(counter, Name, _Config) ->
@@ -33,3 +33,13 @@ update(Name, {c, I}, _Config) when I < 0 ->
   folsom_metrics:notify(Name, {dec, abs(I)});
 update(Name, Val, _Config) ->
   folsom_metrics:notify(Name, Val).
+
+update_or_create(Name, Probe, Type, Config) ->
+  case update(Name, Probe, Config) of
+    ok -> ok;
+    {error, Name, nonexistent_metric} ->
+      new(Type, Name, Config),
+      update(Name, Probe, Config);
+    Error ->
+      Error
+  end.

src/metrics_grapherl.erl

@@ -19,7 +19,7 @@
 -author("Benoit Chesneau").
 
 %% API
--export([init/0, new/3, update/3]).
+-export([init/0, new/3, update/3, update_or_create/4]).
 
 -export([send_metrics/3]).
 
@@ -33,9 +33,9 @@ new(counter, _Name, _Config) -> ok;
 new(gauge, _Name, _Config) -> ok;
 new(_, _, _) -> {error, unsupported_type}.
 
-update(Name, Probe, Config) ->
-  spawn(?MODULE, send_metrics, [Name, Probe, Config]).
+update(Name, Probe, Config) -> spawn(?MODULE, send_metrics, [Name, Probe, Config]).
 
+update_or_create(Name, Probe, _Type, Config) -> update(Name, Probe, Config).
 
 parse_address({_, _, _, _}=Addr) -> Addr;
 parse_address({_, _, _, _, _, _, _, _}= Addr) -> Addr;

src/metrics_noop.erl

@@ -12,7 +12,8 @@
 -author("Benoit Chesneau").
 
 %% API
--export([new/3, update/3]).
+-export([new/3, update/3, update_or_create/4]).
 
 new(_Name, _Type, _Config) ->  ok.
 update(_Name, _Probe, _Config) ->  ok.
+update_or_create(_Name, _Probe, _Type, _Config) -> ok.

test/metrics_tests.erl

@@ -34,7 +34,8 @@ folsom_test_() ->
         fun folsom_counter_test_/1,
         fun folsom_counter_test_inc_/1,
         fun folsom_counter_test_mul_/1,
-        fun folsom_gauge_test_/1
+        fun folsom_gauge_test_/1,
+        fun folsom_update_or_create_/1
       ]
     }
   }.
@@ -50,7 +51,8 @@ exometer_test_() ->
         fun exometer_counter_test_/1,
         fun exometer_counter_test_inc_/1,
         fun exometer_counter_test_mul_/1,
-        fun exometer_gauge_test_/1
+        fun exometer_gauge_test_/1,
+        fun exometer_update_or_create_/1
       ]
     }
   }.
@@ -82,6 +84,11 @@ folsom_gauge_test_(_) ->
   metrics:update("g", 1),
   ?_assertEqual(1, folsom_metrics:get_metric_value("g")).
 
+folsom_update_or_create_(_) ->
+  ok = metrics:backend(metrics_folsom),
+  metrics:update_or_create("new_counter", {c, 1}, counter),
+  ?_assertEqual(1, folsom_metrics:get_metric_value("new_counter")).
+
 exometer_counter_test_(_) ->
   ok = metrics:backend(metrics_exometer),
   ok = metrics:new(counter, "c1"),
@@ -109,4 +116,7 @@ exometer_gauge_test_(_) ->
   metrics:update("g1", 1),
   ?_assertMatch({ok, [{value, 1}, _]}, exometer:get_value("g1")).
 
-
+exometer_update_or_create_(_) ->
+  ok = metrics:backend(metrics_exometer),
+  metrics:update_or_create("new_exo_counter", {c, 1}, counter),
+  ?_assertMatch({ok, [{value, 1}, _]}, exometer:get_value("new_exo_counter")).