Add metrics:delete/1

src/metrics.erl

@@ -15,6 +15,7 @@
 -export([update/1, update/2]).
 -export([update_or_create/3]).
 -export([backend/0, backend/1]).
+-export([delete/1]).
 
 -export([start_link/0]).
 
@@ -67,6 +68,11 @@ update(Name, Probe) ->
 update_or_create(Name, Probe, Type) ->
   metrics_mod:update_or_create(Name, Probe, Type).
 
+%% @doc delete a metric
+-spec delete(list()) -> ok | any().
+delete(Name) ->
+  metrics_mod:delete(Name).
+
 
 %% @doc retrieve the current backend name
 -spec backend() -> atom().
@@ -172,9 +178,11 @@ build_metrics_mod(Mod, Config) when is_atom(Mod), is_map(Config) ->
     [?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@)")]),
+  Delete = erl_syntax:function(merl:term('delete'),
+    [?Q("(Name) -> _@Mod@:delete(Name, _@Config@)")]),
   Module = ?Q("-module('metrics_mod')."),
-  Exported = ?Q("-export(['new'/2, 'update'/2, 'update_or_create'/3])."),
-  Functions = [ ?Q("'@_F'() -> [].") || F <- [New, Update, UpdateOrCreate]],
+  Exported = ?Q("-export(['new'/2, 'update'/2, 'update_or_create'/3, 'delete'/1])."),
+  Functions = [ ?Q("'@_F'() -> [].") || F <- [New, Update, UpdateOrCreate, Delete]],
   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, update_or_create/4]).
+-export([new/3, update/3, update_or_create/4, delete/2]).
 
 
 -spec new(atom(), any(), map()) -> ok | {error, metric_exists | unsupported_type}.
@@ -35,3 +35,6 @@ 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, []).
+
+delete(Name, _Config) ->
+  exometer:delete(Name).

src/metrics_folsom.erl

@@ -11,7 +11,7 @@
 -author("Benoit Chesneau").
 
 %% API
--export([new/3, update/3, update_or_create/4]).
+-export([new/3, update/3, update_or_create/4, delete/2]).
 
 -spec new(atom(), any(), map()) -> ok | {error, term()}.
 new(counter, Name, _Config) ->
@@ -43,3 +43,6 @@ update_or_create(Name, Probe, Type, Config) ->
     Error ->
       Error
   end.
+
+delete(Name, _Config) ->
+  folsom_metrics:delete_metric(Name).

src/metrics_grapherl.erl

@@ -19,7 +19,7 @@
 -author("Benoit Chesneau").
 
 %% API
--export([init/0, new/3, update/3, update_or_create/4]).
+-export([init/0, new/3, update/3, update_or_create/4, delete/2]).
 
 -export([send_metrics/3]).
 
@@ -37,6 +37,8 @@ update(Name, Probe, Config) -> spawn(?MODULE, send_metrics, [Name, Probe, Config
 
 update_or_create(Name, Probe, _Type, Config) -> update(Name, Probe, Config).
 
+delete(_Name, _Config) -> ok.
+
 parse_address({_, _, _, _}=Addr) -> Addr;
 parse_address({_, _, _, _, _, _, _, _}= Addr) -> Addr;
 parse_address(S) when is_binary(S) ->

src/metrics_noop.erl

@@ -12,8 +12,9 @@
 -author("Benoit Chesneau").
 
 %% API
--export([new/3, update/3, update_or_create/4]).
+-export([new/3, update/3, update_or_create/4, delete/2]).
 
 new(_Name, _Type, _Config) ->  ok.
 update(_Name, _Probe, _Config) ->  ok.
 update_or_create(_Name, _Probe, _Type, _Config) -> ok.
+delete(_Name, _Config) -> ok.

test/metrics_tests.erl

@@ -35,7 +35,8 @@ folsom_test_() ->
         fun folsom_counter_test_inc_/1,
         fun folsom_counter_test_mul_/1,
         fun folsom_gauge_test_/1,
-        fun folsom_update_or_create_/1
+        fun folsom_update_or_create_/1,
+        fun folsom_delete_/1
       ]
     }
   }.
@@ -52,7 +53,8 @@ exometer_test_() ->
         fun exometer_counter_test_inc_/1,
         fun exometer_counter_test_mul_/1,
         fun exometer_gauge_test_/1,
-        fun exometer_update_or_create_/1
+        fun exometer_update_or_create_/1,
+        fun exometer_delete_/1
       ]
     }
   }.
@@ -89,6 +91,13 @@ folsom_update_or_create_(_) ->
   metrics:update_or_create("new_counter", {c, 1}, counter),
   ?_assertEqual(1, folsom_metrics:get_metric_value("new_counter")).
 
+folsom_delete_(_) ->
+  ok = metrics:backend(metrics_folsom),
+  ok = metrics:new(gauge, "g"),
+  ok = metrics:new(counter, "c"),
+  ok = metrics:delete("g"),
+  ?_assertEqual(["c"], folsom_metrics:get_metrics()).
+
 exometer_counter_test_(_) ->
   ok = metrics:backend(metrics_exometer),
   ok = metrics:new(counter, "c1"),
@@ -120,3 +129,10 @@ 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")).
+
+exometer_delete_(_) ->
+  ok = metrics:backend(metrics_exometer),
+  ok = metrics:new(gauge, "g"),
+  ok = metrics:new(counter, "c"),
+  ok = metrics:delete("g"),
+  ?_assertEqual(undefined, exometer:info("g", status)).