From 18e2a2ce56308eaaab96466be239d5c394ad6835 Mon Sep 17 00:00:00 2001
From: EMQ-YangM <yangm@emqx.io>
Date: Wed, 6 Apr 2022 15:30:04 +0800
Subject: [PATCH] feat: impl reset_metrics

---
 .../src/emqx_plugin_libs_metrics.erl          | 23 +++++++++++
 .../test/emqx_plugin_libs_metrics_SUITE.erl   | 38 +++++++++++++++++++
 2 files changed, 61 insertions(+)

diff --git a/apps/emqx_plugin_libs/src/emqx_plugin_libs_metrics.erl b/apps/emqx_plugin_libs/src/emqx_plugin_libs_metrics.erl
index 241f8ff2a..98c4490ee 100644
--- a/apps/emqx_plugin_libs/src/emqx_plugin_libs_metrics.erl
+++ b/apps/emqx_plugin_libs/src/emqx_plugin_libs_metrics.erl
@@ -32,6 +32,7 @@
         , create_metrics/3
         , create_metrics/4
         , clear_metrics/2
+        , reset_metrics/2
         , has_metrics/2
         ]).
 
@@ -116,6 +117,10 @@ create_metrics(Name, Id, Metrics, RateMetrics) ->
 clear_metrics(Name, Id) ->
     gen_server:call(Name, {delete_metrics, Id}).
 
+-spec(reset_metrics(handler_name(), metric_id()) -> ok).
+reset_metrics(Name, Id) ->
+    gen_server:call(Name, {reset_metrics, Id}).
+
 -spec(has_metrics(handler_name(), metric_id()) -> boolean()).
 has_metrics(Name, Id) ->
     case get_ref(Name, Id) of
@@ -143,6 +148,13 @@ get_counters(Name, Id) ->
             get(Name, Id, Index)
         end, get_indexes(Name, Id)).
 
+-spec reset_counters(handler_name(), metric_id()) -> ok.
+reset_counters(Name, Id) ->
+    Indexes = maps:values(get_indexes(Name, Id)),
+    Ref = get_ref(Name, Id),
+    [counters:put(Ref, Idx, 0) || Idx <- Indexes ],
+    ok.
+
 -spec(get_metrics(handler_name(), metric_id()) -> metrics()).
 get_metrics(Name, Id) ->
     #{rate => get_rate(Name, Id), counters => get_counters(Name, Id)}.
@@ -198,6 +210,17 @@ handle_call({delete_metrics, Id}, _From,
                         _ -> maps:remove(Id, Rates)
                     end}};
 
+handle_call({reset_metrics, Id}, _From,
+            State = #state{rates = Rates}) ->
+    {reply, reset_counters(get_self_name(), Id),
+     State#state{rates = case Rates of
+                             undefined -> undefined;
+                             _ -> ResetRate =
+                                      maps:map(fun(_Key, _Value) -> #rate{} end,
+                                               maps:get(Id, Rates, #{})),
+                                  maps:put(Id, ResetRate, Rates)
+                         end}};
+
 handle_call(_Request, _From, State) ->
     {reply, ok, State}.
 
diff --git a/apps/emqx_plugin_libs/test/emqx_plugin_libs_metrics_SUITE.erl b/apps/emqx_plugin_libs/test/emqx_plugin_libs_metrics_SUITE.erl
index 25c253a9a..3ae480c22 100644
--- a/apps/emqx_plugin_libs/test/emqx_plugin_libs_metrics_SUITE.erl
+++ b/apps/emqx_plugin_libs/test/emqx_plugin_libs_metrics_SUITE.erl
@@ -85,6 +85,44 @@ t_get_metrics(_) ->
      ?assert(MaxA > 0), ?assert(MaxB > 0), ?assert(MaxC > 0)}),
     ok = emqx_plugin_libs_metrics:clear_metrics(?NAME, <<"testid">>).
 
+t_reset_metrics(_) ->
+    Metrics = [a, b, c],
+    ok = emqx_plugin_libs_metrics:create_metrics(?NAME, <<"testid">>, Metrics),
+    %% all the metrics are set to zero at start
+    ?assertMatch(#{
+        rate := #{
+            a := #{current := 0.0, max := 0.0, last5m := 0.0},
+            b := #{current := 0.0, max := 0.0, last5m := 0.0},
+            c := #{current := 0.0, max := 0.0, last5m := 0.0}
+        },
+        counters := #{
+            a := 0,
+            b := 0,
+            c := 0
+        }
+    }, emqx_plugin_libs_metrics:get_metrics(?NAME, <<"testid">>)),
+    ok = emqx_plugin_libs_metrics:inc(?NAME, <<"testid">>, a),
+    ok = emqx_plugin_libs_metrics:inc(?NAME, <<"testid">>, b),
+    ok = emqx_plugin_libs_metrics:inc(?NAME, <<"testid">>, c),
+    ok = emqx_plugin_libs_metrics:inc(?NAME, <<"testid">>, c),
+    ct:sleep(1500),
+    ok = emqx_plugin_libs_metrics:reset_metrics(?NAME, <<"testid">>),
+    ?LET(#{
+        rate := #{
+            a := #{current := CurrA, max := MaxA, last5m := _},
+            b := #{current := CurrB, max := MaxB, last5m := _},
+            c := #{current := CurrC, max := MaxC, last5m := _}
+        },
+        counters := #{
+            a := 0,
+            b := 0,
+            c := 0
+        }
+    }, emqx_plugin_libs_metrics:get_metrics(?NAME, <<"testid">>),
+    {?assert(CurrA == 0), ?assert(CurrB == 0), ?assert(CurrC == 0),
+     ?assert(MaxA == 0), ?assert(MaxB == 0), ?assert(MaxC == 0)}),
+    ok = emqx_plugin_libs_metrics:clear_metrics(?NAME, <<"testid">>).
+
 t_get_metrics_2(_) ->
     Metrics = [a, b, c],
     ok = emqx_plugin_libs_metrics:create_metrics(?NAME, <<"testid">>, Metrics,