Merge pull request #1975 from sirihansen/siri/logger/config-set-or-update

Forward set/update indicator to handler callback changing_config
OTP-15364

5 files changed, 234 insertions, 100 deletions

diff --git a/lib/kernel/src/logger.erl b/lib/kernel/src/logger.erl
index 752dd8d493..6762998d4f 100644
--- a/lib/kernel/src/logger.erl
+++ b/lib/kernel/src/logger.erl
@@ -43,7 +43,8 @@
          get_module_level/0, get_module_level/1,
          set_primary_config/1, set_primary_config/2,
          set_handler_config/2, set_handler_config/3,
-         update_primary_config/1, update_handler_config/2,
+         update_primary_config/1,
+         update_handler_config/2, update_handler_config/3,
          update_formatter_config/2, update_formatter_config/3,
          get_primary_config/0, get_handler_config/1,
          get_handler_config/0, get_handler_ids/0, get_config/0,
@@ -423,6 +424,29 @@ set_handler_config(HandlerId,Config) ->
 update_primary_config(Config) ->
     logger_server:update_config(primary,Config).
 
+-spec update_handler_config(HandlerId,level,Level) -> Return when
+      HandlerId :: handler_id(),
+      Level :: level() | all | none,
+      Return :: ok | {error,term()};
+                        (HandlerId,filter_default,FilterDefault) -> Return when
+      HandlerId :: handler_id(),
+      FilterDefault :: log | stop,
+      Return :: ok | {error,term()};
+                        (HandlerId,filters,Filters) -> Return when
+      HandlerId :: handler_id(),
+      Filters :: [{filter_id(),filter()}],
+      Return :: ok | {error,term()};
+                        (HandlerId,formatter,Formatter) -> Return when
+      HandlerId :: handler_id(),
+      Formatter :: {module(), formatter_config()},
+      Return :: ok | {error,term()};
+                        (HandlerId,config,Config) -> Return when
+      HandlerId :: handler_id(),
+      Config :: term(),
+      Return :: ok | {error,term()}.
+update_handler_config(HandlerId,Key,Value) ->
+    logger_server:update_config(HandlerId,Key,Value).
+
 -spec update_handler_config(HandlerId,Config) -> ok | {error,term()} when
       HandlerId :: handler_id(),
       Config :: handler_config().
@@ -439,7 +463,14 @@ get_primary_config() ->
       HandlerId :: handler_id(),
       Config :: handler_config().
 get_handler_config(HandlerId) ->
-    logger_config:get(?LOGGER_TABLE,HandlerId).
+    case logger_config:get(?LOGGER_TABLE,HandlerId) of
+        {ok,#{module:=Module}=Config} ->
+            {ok,try Module:filter_config(Config)
+                catch _:_ -> Config
+                end};
+        Error ->
+            Error
+    end.
 
 -spec get_handler_config() -> [Config] when
       Config :: handler_config().
diff --git a/lib/kernel/src/logger_disk_log_h.erl b/lib/kernel/src/logger_disk_log_h.erl
index a8f141f135..2a81458ec8 100644
--- a/lib/kernel/src/logger_disk_log_h.erl
+++ b/lib/kernel/src/logger_disk_log_h.erl
@@ -33,7 +33,8 @@
          terminate/2, code_change/3]).
 
 %% logger callbacks
--export([log/2, adding_handler/1, removing_handler/1, changing_config/2]).
+-export([log/2, adding_handler/1, removing_handler/1, changing_config/3,
+         filter_config/1]).
 
 %% handler internal
 -export([log_handler_info/4]).
@@ -114,9 +115,8 @@ reset(Name) ->
 %%% Handler being added
 adding_handler(#{id:=Name}=Config) ->
     case check_config(adding, Config) of
-        {ok, Config1} ->
+        {ok, #{config:=HConfig}=Config1} ->
             %% create initial handler state by merging defaults with config
-            HConfig = maps:get(config, Config1, #{}),
             HState = maps:merge(get_init_state(), HConfig),
             case logger_h_common:overload_levels_ok(HState) of
                 true ->
@@ -133,32 +133,40 @@ adding_handler(#{id:=Name}=Config) ->
 
 %%%-----------------------------------------------------------------
 %%% Updating handler config
-changing_config(OldConfig = #{id:=Name, config:=OldHConfig},
-                NewConfig = #{id:=Name, config:=NewHConfig}) ->
-    #{type:=Type, file:=File, max_no_files:=MaxFs,
-      max_no_bytes:=MaxBytes} = OldHConfig,
-    case NewHConfig of
-        #{type:=Type, file:=File, max_no_files:=MaxFs,
-          max_no_bytes:=MaxBytes} ->
-            changing_config1(OldConfig, NewConfig);
-        _ ->
-            {error,{illegal_config_change,OldConfig,NewConfig}}
-    end;
-changing_config(OldConfig, NewConfig) ->
-    {error,{illegal_config_change,OldConfig,NewConfig}}.
+changing_config(SetOrUpdate,OldConfig=#{config:=OldHConfig},NewConfig) ->
+    WriteOnce = maps:with([type,file,max_no_files,max_no_bytes],OldHConfig),
+    ReadOnly = maps:with([handler_pid,mode_tab],OldHConfig),
+    NewHConfig0 = maps:get(config, NewConfig, #{}),
+    Default =
+        case SetOrUpdate of
+            set ->
+                %% Do not reset write-once fields to defaults
+                maps:merge(get_default_config(),WriteOnce);
+            update ->
+                OldHConfig
+        end,
 
-changing_config1(OldConfig=#{config:=OldHConfig}, NewConfig) ->
+    %% Allow (accidentially) included read-only fields - just overwrite them
+    NewHConfig = maps:merge(maps:merge(Default,NewHConfig0),ReadOnly),
+
+    %% But fail if write-once fields are changed
+    case maps:with([type,file,max_no_files,max_no_bytes],NewHConfig) of
+        WriteOnce ->
+            changing_config1(maps:get(handler_pid,OldHConfig),
+                             OldConfig,
+                             NewConfig#{config=>NewHConfig});
+        Other ->
+            {Old,New} = logger_server:diff_maps(WriteOnce,Other),
+            {error,{illegal_config_change,#{config=>Old},#{config=>New}}}
+    end.
+
+changing_config1(HPid, OldConfig, NewConfig) ->
     case check_config(changing, NewConfig) of
-        {ok,NewConfig1 = #{config:=NewHConfig}} ->
-            #{handler_pid:=HPid,
-              mode_tab:=ModeTab} = OldHConfig,
-            NewHConfig1 = NewHConfig#{handler_pid=>HPid,
-                                      mode_tab=>ModeTab},
-            NewConfig2 = NewConfig1#{config=>NewHConfig1},
-            try gen_server:call(HPid, {change_config,OldConfig,NewConfig2},
+        Result = {ok,NewConfig1} ->
+            try gen_server:call(HPid, {change_config,OldConfig,NewConfig1},
                                 ?DEFAULT_CALL_TIMEOUT) of
-                ok      -> {ok,NewConfig2};
-                HError  -> HError
+                ok      -> Result;
+                Error  -> Error
             catch
                 _:{timeout,_} -> {error,handler_busy}
             end;
@@ -168,10 +176,12 @@ changing_config1(OldConfig=#{config:=OldHConfig}, NewConfig) ->
 
 check_config(adding, #{id:=Name}=Config) ->
     %% merge handler specific config data
-    HConfig = merge_default_logopts(Name, maps:get(config, Config, #{})),
-    case check_h_config(maps:to_list(HConfig)) of
+    HConfig1 = maps:get(config, Config, #{}),
+    HConfig2 = maps:merge(get_default_config(), HConfig1),
+    HConfig3 = merge_default_logopts(Name, HConfig2),
+    case check_h_config(maps:to_list(HConfig3)) of
         ok ->
-            {ok,Config#{config=>HConfig}};
+            {ok,Config#{config=>HConfig3}};
         Error ->
             Error
     end;
@@ -238,6 +248,11 @@ log(LogEvent, Config = #{id := Name,
     Bin = logger_h_common:log_to_binary(LogEvent, Config),
     logger_h_common:call_cast_or_drop(Name, HPid, ModeTab, Bin).
 
+%%%-----------------------------------------------------------------
+%%% Remove internal fields from configuration
+filter_config(#{config:=HConfig}=Config) ->
+    Config#{config=>maps:without([handler_pid,mode_tab],HConfig)}.
+
 %%%===================================================================
 %%% gen_server callbacks
 %%%===================================================================
@@ -438,7 +453,7 @@ code_change(_OldVsn, State, _Extra) ->
 
 %%%-----------------------------------------------------------------
 %%%
-get_init_state() ->
+get_default_config() ->
      #{sync_mode_qlen              => ?SYNC_MODE_QLEN,
        drop_mode_qlen              => ?DROP_MODE_QLEN,
        flush_qlen                  => ?FLUSH_QLEN,
@@ -449,10 +464,12 @@ get_init_state() ->
        overload_kill_qlen          => ?OVERLOAD_KILL_QLEN,
        overload_kill_mem_size      => ?OVERLOAD_KILL_MEM_SIZE,
        overload_kill_restart_after => ?OVERLOAD_KILL_RESTART_AFTER,
-       dl_sync_int                 => ?CONTROLLER_SYNC_INTERVAL,
-       filesync_ok_qlen            => ?FILESYNC_OK_QLEN,
        filesync_repeat_interval    => ?FILESYNC_REPEAT_INTERVAL}.
 
+get_init_state() ->
+     #{dl_sync_int                 => ?CONTROLLER_SYNC_INTERVAL,
+       filesync_ok_qlen            => ?FILESYNC_OK_QLEN}.
+
 %%%-----------------------------------------------------------------
 %%% Add a disk_log handler to the logger.
 %%% This starts a dedicated handler process which should always
diff --git a/lib/kernel/src/logger_h_common.erl b/lib/kernel/src/logger_h_common.erl
index 38ac7d8ffc..94c640cb92 100644
--- a/lib/kernel/src/logger_h_common.erl
+++ b/lib/kernel/src/logger_h_common.erl
@@ -306,8 +306,11 @@ stop_or_restart(Name, {shutdown,Reason={overloaded,_Name,_QLen,_Mem}},
                         exit(HandlerPid, kill)
                 end,
                 case ConfigResult of
-                    {ok,#{module:=HMod}=HConfig} when is_integer(RestartAfter) ->
+                    {ok,#{module:=HMod}=HConfig0} when is_integer(RestartAfter) ->
                         _ = logger:remove_handler(Name),
+                        HConfig = try HMod:filter_config(HConfig0)
+                                  catch _:_ -> HConfig0
+                                  end,
                         _ = timer:apply_after(RestartAfter, logger, add_handler,
                                               [Name,HMod,HConfig]);
                     {ok,_} ->
diff --git a/lib/kernel/src/logger_server.erl b/lib/kernel/src/logger_server.erl
index a1d40f1123..b7735dbcf7 100644
--- a/lib/kernel/src/logger_server.erl
+++ b/lib/kernel/src/logger_server.erl
@@ -27,9 +27,13 @@
          add_filter/2, remove_filter/2,
          set_module_level/2, unset_module_level/0,
          unset_module_level/1, cache_module_level/1,
-         set_config/2, set_config/3, update_config/2,
+         set_config/2, set_config/3,
+         update_config/2, update_config/3,
          update_formatter_config/2]).
 
+%% Helper
+-export([diff_maps/2]).
+
 %% gen_server callbacks
 -export([init/1, handle_call/3, handle_cast/2, handle_info/2,
          terminate/2]).
@@ -105,12 +109,25 @@ cache_module_level(Module) ->
     gen_server:cast(?SERVER,{cache_module_level,Module}).
 
 set_config(Owner,Key,Value) ->
-    update_config(Owner,#{Key=>Value}).
+    case sanity_check(Owner,Key,Value) of
+        ok ->
+            call({change_config,set,Owner,Key,Value});
+        Error ->
+            Error
+    end.
 
 set_config(Owner,Config) ->
     case sanity_check(Owner,Config) of
         ok ->
-            call({set_config,Owner,Config});
+            call({change_config,set,Owner,Config});
+        Error ->
+            Error
+    end.
+
+update_config(Owner,Key,Value) ->
+    case sanity_check(Owner,Key,Value) of
+        ok ->
+            call({change_config,update,Owner,Key,Value});
         Error ->
             Error
     end.
@@ -118,7 +135,7 @@ set_config(Owner,Config) ->
 update_config(Owner, Config) ->
     case sanity_check(Owner,Config) of
         ok ->
-            call({update_config,Owner,Config});
+            call({change_config,update,Owner,Config});
         Error ->
             Error
     end.
@@ -204,46 +221,72 @@ handle_call({add_filter,Id,Filter}, _From,#state{tid=Tid}=State) ->
 handle_call({remove_filter,Id,FilterId}, _From, #state{tid=Tid}=State) ->
     Reply = do_remove_filter(Tid,Id,FilterId),
     {reply,Reply,State};
-handle_call({update_config,primary,NewConfig}, _From, #state{tid=Tid}=State) ->
+handle_call({change_config,SetOrUpd,primary,Config0}, _From,
+            #state{tid=Tid}=State) ->
+    {ok,#{handlers:=Handlers}=OldConfig} = logger_config:get(Tid,primary),
+    Default =
+        case SetOrUpd of
+            set -> default_config(primary);
+            update -> OldConfig
+        end,
+    Config = maps:merge(Default,Config0),
+    Reply = logger_config:set(Tid,primary,Config#{handlers=>Handlers}),
+    {reply,Reply,State};
+handle_call({change_config,_SetOrUpd,primary,Key,Value}, _From,
+            #state{tid=Tid}=State) ->
     {ok,OldConfig} = logger_config:get(Tid,primary),
-    Config = maps:merge(OldConfig,NewConfig),
-    {reply,logger_config:set(Tid,primary,Config),State};
-handle_call({update_config,HandlerId,NewConfig}, From, #state{tid=Tid}=State) ->
+    Reply = logger_config:set(Tid,primary,OldConfig#{Key=>Value}),
+    {reply,Reply,State};
+handle_call({change_config,SetOrUpd,HandlerId,Config0}, From,
+            #state{tid=Tid}=State) ->
     case logger_config:get(Tid,HandlerId) of
         {ok,#{module:=Module}=OldConfig} ->
-            Config = maps:merge(OldConfig,NewConfig),
-            call_h_async(
-              fun() ->
-                      call_h(Module,changing_config,[OldConfig,Config],
-                             {ok,Config})
-              end,
-              fun({ok,Config1}) ->
-                      logger_config:set(Tid,HandlerId,Config1);
-                 (Error) ->
-                      Error
-              end,From,State);
-        Error ->
-            {reply,Error,State}
+            Default =
+                case SetOrUpd of
+                    set -> default_config(HandlerId,Module);
+                    update -> OldConfig
+                end,
+            Config = maps:merge(Default,Config0),
+            case check_config_change(OldConfig,Config) of
+                ok ->
+                    call_h_async(
+                      fun() ->
+                              call_h(Module,changing_config,
+                                     [SetOrUpd,OldConfig,Config],
+                                     {ok,Config})
+                      end,
+                      fun({ok,Config1}) ->
+                              logger_config:set(Tid,HandlerId,Config1);
+                         (Error) ->
+                              Error
+                      end,From,State);
+                Error ->
+                    {reply,Error,State}
+            end;
+        _ ->
+            {reply,{error,{not_found,HandlerId}},State}
     end;
-handle_call({set_config,primary,Config0}, _From, #state{tid=Tid}=State) ->
-    Config = maps:merge(default_config(primary),Config0),
-    {ok,#{handlers:=Handlers}} = logger_config:get(Tid,primary),
-    Reply = logger_config:set(Tid,primary,Config#{handlers=>Handlers}),
-    {reply,Reply,State};
-handle_call({set_config,HandlerId,Config0}, From, #state{tid=Tid}=State) ->
+handle_call({change_config,SetOrUpd,HandlerId,Key,Value}, From,
+            #state{tid=Tid}=State) ->
     case logger_config:get(Tid,HandlerId) of
         {ok,#{module:=Module}=OldConfig} ->
-            Config = maps:merge(default_config(HandlerId,Module),Config0),
-            call_h_async(
-              fun() ->
-                      call_h(Module,changing_config,[OldConfig,Config],
-                             {ok,Config})
-              end,
-              fun({ok,Config1}) ->
-                      logger_config:set(Tid,HandlerId,Config1);
-                 (Error) ->
-                      Error
-              end,From,State);
+            Config = OldConfig#{Key=>Value},
+            case check_config_change(OldConfig,Config) of
+                ok ->
+                    call_h_async(
+                      fun() ->
+                              call_h(Module,changing_config,
+                                     [SetOrUpd,OldConfig,Config],
+                                     {ok,Config})
+                      end,
+                      fun({ok,Config1}) ->
+                              logger_config:set(Tid,HandlerId,Config1);
+                         (Error) ->
+                              Error
+                      end,From,State);
+                Error ->
+                    {reply,Error,State}
+            end;
         _ ->
             {reply,{error,{not_found,HandlerId}},State}
     end;
@@ -320,7 +363,7 @@ call(Request) ->
         true when
               Action == add_handler; Action == remove_handler;
               Action == add_filter; Action == remove_filter;
-              Action == update_config; Action == set_config ->
+              Action == change_config ->
             {error,{attempting_syncronous_call_to_self,Request}};
         _ ->
             gen_server:call(?SERVER,Request,?DEFAULT_LOGGER_CALL_TIMEOUT)
@@ -458,6 +501,15 @@ check_formatter({Mod,Config}) ->
 check_formatter(Formatter) ->
     throw({invalid_formatter,Formatter}).
 
+%% When changing configuration for a handler, the id and module fields
+%% can not be changed.
+check_config_change(#{id:=Id,module:=Module},#{id:=Id,module:=Module}) ->
+    ok;
+check_config_change(OldConfig,NewConfig) ->
+    {Old,New} = logger_server:diff_maps(maps:with([id,module],OldConfig),
+                                        maps:with([id,module],NewConfig)),
+    {error,{illegal_config_change,Old,New}}.
+
 call_h(Module, Function, Args, DefRet) ->
     %% Not calling code:ensure_loaded + erlang:function_exported here,
     %% since in some rare terminal cases, the code_server might not
@@ -466,6 +518,11 @@ call_h(Module, Function, Args, DefRet) ->
     catch
         C:R:S ->
             case {C,R,S} of
+                {error,undef,[{Module,Function=changing_config,Args,_}|_]}
+                  when length(Args)=:=3 ->
+                    %% Backwards compatible call, if changing_config/3
+                    %% did not exist.
+                    call_h(Module, Function, tl(Args), DefRet);
                 {error,undef,[{Module,Function,Args,_}|_]} ->
                     DefRet;
                 _ ->
@@ -525,3 +582,14 @@ call_h_reply(Unexpected,State) ->
                    {process,?SERVER},
                    {message,Unexpected}]),
     {noreply,State}.
+
+%% Return two maps containing only the fields that differ.
+diff_maps(M1,M2) ->
+    diffs(lists:sort(maps:to_list(M1)),lists:sort(maps:to_list(M2)),#{},#{}).
+
+diffs([H|T1],[H|T2],D1,D2) ->
+    diffs(T1,T2,D1,D2);
+diffs([{K,V1}|T1],[{K,V2}|T2],D1,D2) ->
+    diffs(T1,T2,D1#{K=>V1},D2#{K=>V2});
+diffs([],[],D1,D2) ->
+    {D1,D2}.
diff --git a/lib/kernel/src/logger_std_h.erl b/lib/kernel/src/logger_std_h.erl
index 66fa6b6ab6..42e0f5caf4 100644
--- a/lib/kernel/src/logger_std_h.erl
+++ b/lib/kernel/src/logger_std_h.erl
@@ -35,7 +35,8 @@
          terminate/2, code_change/3]).
 
 %% logger callbacks
--export([log/2, adding_handler/1, removing_handler/1, changing_config/2]).
+-export([log/2, adding_handler/1, removing_handler/1, changing_config/3,
+         filter_config/1]).
 
 %% handler internal
 -export([log_handler_info/4]).
@@ -116,9 +117,8 @@ reset(Name) ->
 %%% Handler being added
 adding_handler(#{id:=Name}=Config) ->
     case check_config(adding, Config) of
-        {ok, Config1} ->
+        {ok, #{config:=HConfig}=Config1} ->
             %% create initial handler state by merging defaults with config
-            HConfig = maps:get(config, Config1, #{}),
             HState = maps:merge(get_init_state(), HConfig),
             case logger_h_common:overload_levels_ok(HState) of
                 true ->
@@ -135,22 +135,31 @@ adding_handler(#{id:=Name}=Config) ->
 
 %%%-----------------------------------------------------------------
 %%% Updating handler config
-changing_config(OldConfig=#{id:=Name, config:=OldHConfig},
-                NewConfig=#{id:=Name}) ->
-    #{type:=Type, handler_pid:=HPid, mode_tab:=ModeTab} = OldHConfig,
-    NewHConfig = maps:get(config, NewConfig, #{}),
-    case maps:get(type, NewHConfig, Type) of
-        Type ->
-            NewHConfig1 = NewHConfig#{type=>Type,
-                                      handler_pid=>HPid,
-                                      mode_tab=>ModeTab},
-            changing_config1(HPid, OldConfig,
-                             NewConfig#{config=>NewHConfig1});
-        _ ->
-            {error,{illegal_config_change,OldConfig,NewConfig}}
-    end;
-changing_config(OldConfig, NewConfig) ->
-    {error,{illegal_config_change,OldConfig,NewConfig}}.
+changing_config(SetOrUpdate,OldConfig=#{config:=OldHConfig},NewConfig) ->
+    WriteOnce = maps:with([type],OldHConfig),
+    ReadOnly = maps:with([handler_pid,mode_tab],OldHConfig),
+    NewHConfig0 = maps:get(config, NewConfig, #{}),
+    Default =
+        case SetOrUpdate of
+            set ->
+                %% Do not reset write-once fields to defaults
+                maps:merge(get_default_config(),WriteOnce);
+            update ->
+                OldHConfig
+        end,
+
+    %% Allow (accidentially) included read-only fields - just overwrite them
+    NewHConfig = maps:merge(maps:merge(Default, NewHConfig0),ReadOnly),
+
+    %% But fail if write-once fields are changed
+    case maps:with([type],NewHConfig) of
+        WriteOnce ->
+            changing_config1(maps:get(handler_pid,OldHConfig),
+                             OldConfig,
+                             NewConfig#{config=>NewHConfig});
+        Other ->
+            {error,{illegal_config_change,#{config=>WriteOnce},#{config=>Other}}}
+    end.
 
 changing_config1(HPid, OldConfig, NewConfig) ->
     case check_config(changing, NewConfig) of
@@ -169,8 +178,7 @@ changing_config1(HPid, OldConfig, NewConfig) ->
 check_config(adding, Config) ->
     %% Merge in defaults on handler level
     HConfig0 = maps:get(config, Config, #{}),
-    HConfig = maps:merge(#{type => standard_io},
-                         HConfig0),
+    HConfig = maps:merge(get_default_config(),HConfig0),
     case check_h_config(maps:to_list(HConfig)) of
         ok ->
             {ok,Config#{config=>HConfig}};
@@ -223,6 +231,11 @@ log(LogEvent, Config = #{id := Name,
     Bin = logger_h_common:log_to_binary(LogEvent, Config),
     logger_h_common:call_cast_or_drop(Name, HPid, ModeTab, Bin).
 
+%%%-----------------------------------------------------------------
+%%% Remove internal fields from configuration
+filter_config(#{config:=HConfig}=Config) ->
+    Config#{config=>maps:without([handler_pid,mode_tab],HConfig)}.
+
 %%%===================================================================
 %%% gen_server callbacks
 %%%===================================================================
@@ -428,8 +441,9 @@ code_change(_OldVsn, State, _Extra) ->
 
 %%%-----------------------------------------------------------------
 %%%
-get_init_state() ->
-     #{sync_mode_qlen              => ?SYNC_MODE_QLEN,
+get_default_config() ->
+     #{type                        => standard_io,
+       sync_mode_qlen              => ?SYNC_MODE_QLEN,
        drop_mode_qlen              => ?DROP_MODE_QLEN,
        flush_qlen                  => ?FLUSH_QLEN,
        burst_limit_enable          => ?BURST_LIMIT_ENABLE,
@@ -439,10 +453,12 @@ get_init_state() ->
        overload_kill_qlen          => ?OVERLOAD_KILL_QLEN,
        overload_kill_mem_size      => ?OVERLOAD_KILL_MEM_SIZE,
        overload_kill_restart_after => ?OVERLOAD_KILL_RESTART_AFTER,
-       file_ctrl_sync_int          => ?CONTROLLER_SYNC_INTERVAL,
-       filesync_ok_qlen            => ?FILESYNC_OK_QLEN,
        filesync_repeat_interval    => ?FILESYNC_REPEAT_INTERVAL}.
 
+get_init_state() ->
+    #{file_ctrl_sync_int          => ?CONTROLLER_SYNC_INTERVAL,
+      filesync_ok_qlen            => ?FILESYNC_OK_QLEN}.
+
 %%%-----------------------------------------------------------------
 %%% Add a standard handler to the logger.
 %%% This starts a dedicated handler process which should always
@@ -825,4 +841,3 @@ sync_dev(Fd, DevName, PrevSyncResult, HandlerName) ->
             logger_h_common:error_notify({HandlerName,filesync,DevName,Error}),
             Error
     end.
-