perf(limiter): simplify the memory represent of limiter configuration

apps/emqx/src/emqx_limiter/src/emqx_htb_limiter.erl

@@ -22,7 +22,7 @@
 
 %% API
 -export([
-    make_token_bucket_limiter/2,
+    make_local_limiter/2,
     make_ref_limiter/2,
     check/2,
     consume/2,
@@ -32,12 +32,11 @@
     make_future/1,
     available/1
 ]).
--export_type([token_bucket_limiter/0]).
+-export_type([local_limiter/0]).
 
-%% a token bucket limiter with a limiter server's bucket reference
-
-%% the number of tokens currently available
--type token_bucket_limiter() :: #{
+%% a token bucket limiter which may or not contains a reference to another limiter,
+%% and can be used in a client alone
+-type local_limiter() :: #{
     tokens := non_neg_integer(),
     rate := decimal(),
     capacity := decimal(),
@@ -58,12 +57,12 @@
     retry_ctx =>
         undefined
         %% the retry context
-        | retry_context(token_bucket_limiter()),
+        | retry_context(local_limiter()),
     %% allow to add other keys
     atom => any()
 }.
 
-%% a limiter server's bucket reference
+%% a limiter instance which only contains a reference to another limiter(bucket)
 -type ref_limiter() :: #{
     max_retry_time := non_neg_integer(),
     failure_strategy := failure_strategy(),
@@ -88,7 +87,7 @@
 }.
 
 -type bucket() :: emqx_limiter_bucket_ref:bucket_ref().
--type limiter() :: token_bucket_limiter() | ref_limiter() | infinity.
+-type limiter() :: local_limiter() | ref_limiter() | infinity.
 -type millisecond() :: non_neg_integer().
 
 -type pause_type() :: pause | partial.
@@ -116,7 +115,7 @@
     rate := decimal(),
     initial := non_neg_integer(),
     low_watermark := non_neg_integer(),
-    capacity := decimal(),
+    burst := decimal(),
     divisible := boolean(),
     max_retry_time := non_neg_integer(),
     failure_strategy := failure_strategy()
@@ -134,8 +133,8 @@
 %%  API
 %%--------------------------------------------------------------------
 %%@doc create a limiter
--spec make_token_bucket_limiter(limiter_bucket_cfg(), bucket()) -> _.
-make_token_bucket_limiter(Cfg, Bucket) ->
+-spec make_local_limiter(limiter_bucket_cfg(), bucket()) -> _.
+make_local_limiter(Cfg, Bucket) ->
     Cfg#{
         tokens => emqx_limiter_server:get_initial_val(Cfg),
         lasttime => ?NOW,
@@ -312,8 +311,8 @@ on_failure(throw, Limiter) ->
     Message = io_lib:format("limiter consume failed, limiter:~p~n", [Limiter]),
     erlang:throw({rate_check_fail, Message}).
 
--spec do_check_with_parent_limiter(pos_integer(), token_bucket_limiter()) ->
-    inner_check_result(token_bucket_limiter()).
+-spec do_check_with_parent_limiter(pos_integer(), local_limiter()) ->
+    inner_check_result(local_limiter()).
 do_check_with_parent_limiter(
     Need,
     #{
@@ -336,7 +335,7 @@ do_check_with_parent_limiter(
             )
     end.
 
--spec do_reset(pos_integer(), token_bucket_limiter()) -> inner_check_result(token_bucket_limiter()).
+-spec do_reset(pos_integer(), local_limiter()) -> inner_check_result(local_limiter()).
 do_reset(
     Need,
     #{

apps/emqx/src/emqx_limiter/src/emqx_limiter_manager.erl

@@ -30,6 +30,12 @@
     post_config_update/5
 ]).
 
+-export([
+    find_root/1,
+    insert_root/2,
+    delete_root/1
+]).
+
 -export([
     start_server/1,
     start_server/2,
@@ -62,6 +68,7 @@
 
 -define(UID(Id, Type), {Id, Type}).
 -define(TAB, emqx_limiter_counters).
+-define(ROOT_ID, root).
 
 %%--------------------------------------------------------------------
 %%  API
@@ -104,9 +111,25 @@ insert_bucket(Id, Type, Bucket) ->
     ).
 
 -spec delete_bucket(limiter_id(), limiter_type()) -> true.
-delete_bucket(Type, Id) ->
+delete_bucket(Id, Type) ->
     ets:delete(?TAB, ?UID(Id, Type)).
 
+-spec find_root(limiter_type()) ->
+    {ok, bucket_ref()} | undefined.
+find_root(Type) ->
+    find_bucket(?ROOT_ID, Type).
+
+-spec insert_root(
+    limiter_type(),
+    bucket_ref()
+) -> boolean().
+insert_root(Type, Bucket) ->
+    insert_bucket(?ROOT_ID, Type, Bucket).
+
+-spec delete_root(limiter_type()) -> true.
+delete_root(Type) ->
+    delete_bucket(?ROOT_ID, Type).
+
 post_config_update([limiter], _Config, NewConf, _OldConf, _AppEnvs) ->
     Types = lists:delete(client, maps:keys(NewConf)),
     _ = [on_post_config_update(Type, NewConf) || Type <- Types],

apps/emqx/src/emqx_limiter/src/emqx_limiter_schema.erl

@@ -32,7 +32,9 @@
     get_bucket_cfg_path/2,
     desc/1,
     types/0,
-    calc_capacity/1
+    calc_capacity/1,
+    extract_with_type/2,
+    default_client_config/0
 ]).
 
 -define(KILOBYTE, 1024).
@@ -94,30 +96,33 @@
 namespace() -> limiter.
 
 roots() ->
-    [{limiter, hoconsc:mk(hoconsc:ref(?MODULE, limiter), #{importance => ?IMPORTANCE_HIDDEN})}].
+    [
+        {limiter,
+            hoconsc:mk(hoconsc:ref(?MODULE, limiter), #{
+                importance => ?IMPORTANCE_HIDDEN
+            })}
+    ].
 
 fields(limiter) ->
     [
         {Type,
             ?HOCON(?R_REF(node_opts), #{
                 desc => ?DESC(Type),
-                default => #{},
                 importance => ?IMPORTANCE_HIDDEN,
                 aliases => alias_of_type(Type)
             })}
      || Type <- types()
     ] ++
         [
+            %% This is an undocumented feature, and it won't be support anymore
             {client,
                 ?HOCON(
                     ?R_REF(client_fields),
                     #{
                         desc => ?DESC(client),
                         importance => ?IMPORTANCE_HIDDEN,
-                        default => maps:from_list([
-                            {erlang:atom_to_binary(Type), #{}}
-                         || Type <- types()
-                        ])
+                        required => {false, recursively},
+                        deprecated => {since, "5.0.25"}
                     }
                 )}
         ];
@@ -131,7 +136,7 @@ fields(node_opts) ->
             })}
     ];
 fields(client_fields) ->
-    client_fields(types(), #{default => #{}});
+    client_fields(types());
 fields(bucket_opts) ->
     fields_of_bucket(<<"infinity">>);
 fields(client_opts) ->
@@ -194,7 +199,7 @@ fields(client_opts) ->
 fields(listener_fields) ->
     composite_bucket_fields(?LISTENER_BUCKET_KEYS, listener_client_fields);
 fields(listener_client_fields) ->
-    client_fields(?LISTENER_BUCKET_KEYS, #{required => false});
+    client_fields(?LISTENER_BUCKET_KEYS);
 fields(Type) ->
     simple_bucket_field(Type).
 
@@ -236,6 +241,31 @@ calc_capacity(#{rate := infinity}) ->
 calc_capacity(#{rate := Rate, burst := Burst}) ->
     erlang:floor(1000 * Rate / default_period()) + Burst.
 
+extract_with_type(_Type, undefined) ->
+    undefined;
+extract_with_type(Type, #{client := ClientCfg} = BucketCfg) ->
+    BucketVal = maps:find(Type, BucketCfg),
+    ClientVal = maps:find(Type, ClientCfg),
+    merge_client_bucket(Type, ClientVal, BucketVal);
+extract_with_type(Type, BucketCfg) ->
+    BucketVal = maps:find(Type, BucketCfg),
+    merge_client_bucket(Type, undefined, BucketVal).
+
+%% Since the client configuration can be absent and be a undefined value,
+%% but we must need some basic settings to control the behaviour of the limiter,
+%% so here add this helper function to generate a default setting.
+%% This is a temporary workaround until we found a better way to simplify.
+default_client_config() ->
+    #{
+        rate => infinity,
+        initial => 0,
+        low_watermark => 0,
+        burst => 0,
+        divisible => false,
+        max_retry_time => timer:seconds(10),
+        failure_strategy => force
+    }.
+
 %%--------------------------------------------------------------------
 %% Internal functions
 %%--------------------------------------------------------------------
@@ -362,7 +392,7 @@ simple_bucket_field(Type) when is_atom(Type) ->
                     ?R_REF(?MODULE, client_opts),
                     #{
                         desc => ?DESC(client),
-                        required => false,
+                        required => {false, recursively},
                         importance => importance_of_type(Type),
                         aliases => alias_of_type(Type)
                     }
@@ -375,7 +405,7 @@ composite_bucket_fields(Types, ClientRef) ->
         {Type,
             ?HOCON(?R_REF(?MODULE, bucket_opts), #{
                 desc => ?DESC(?MODULE, Type),
-                required => false,
+                required => {false, recursively},
                 importance => importance_of_type(Type),
                 aliases => alias_of_type(Type)
             })}
@@ -387,7 +417,7 @@ composite_bucket_fields(Types, ClientRef) ->
                     ?R_REF(?MODULE, ClientRef),
                     #{
                         desc => ?DESC(client),
-                        required => false
+                        required => {false, recursively}
                     }
                 )}
         ].
@@ -410,11 +440,12 @@ fields_of_bucket(Default) ->
             })}
     ].
 
-client_fields(Types, Meta) ->
+client_fields(Types) ->
     [
         {Type,
-            ?HOCON(?R_REF(client_opts), Meta#{
+            ?HOCON(?R_REF(client_opts), #{
                 desc => ?DESC(Type),
+                required => false,
                 importance => importance_of_type(Type),
                 aliases => alias_of_type(Type)
             })}
@@ -436,3 +467,12 @@ alias_of_type(bytes) ->
     [bytes_in];
 alias_of_type(_) ->
     [].
+
+merge_client_bucket(Type, {ok, ClientVal}, {ok, BucketVal}) ->
+    #{Type => BucketVal, client => #{Type => ClientVal}};
+merge_client_bucket(Type, {ok, ClientVal}, _) ->
+    #{client => #{Type => ClientVal}};
+merge_client_bucket(Type, _, {ok, BucketVal}) ->
+    #{Type => BucketVal};
+merge_client_bucket(_, _, _) ->
+    undefined.