Revert decision to throw a {sink, Sink} tuple at every backend; instead, special case the throttle

src/error_logger_lager_h.erl

@@ -74,7 +74,7 @@ set_high_water(N) ->
     gen_event:call(error_logger, ?MODULE, {set_high_water, N}, infinity).
 
 -spec init(any()) -> {ok, #state{}}.
-init([{sink, Sink}, HighWaterMark]) ->
+init([HighWaterMark]) ->
     {ok, #state{hwm=HighWaterMark}}.
 
 handle_call({set_high_water, N}, State) ->

src/lager_console_backend.erl

@@ -40,8 +40,6 @@
 %% @private
 init([Level]) when is_atom(Level) ->
     init(Level);
-init([{sink, _Sink}|T]) ->
-    init(T);
 init([Level, true]) -> % for backwards compatibility
     init([Level,{lager_default_formatter,[{eol, eol()}]}]);
 init([Level,false]) -> % for backwards compatibility
@@ -188,7 +186,7 @@ console_log_test_() ->
                         unregister(user),
                         register(user, Pid),
                         erlang:group_leader(Pid, whereis(lager_event)),
-                        gen_event:add_handler(lager_event, lager_console_backend, [{sink, lager_event}, info]),
+                        gen_event:add_handler(lager_event, lager_console_backend, info),
                         lager_config:set({lager_event, loglevel}, {element(2, lager_util:config_to_mask(info)), []}),
                         lager:log(info, self(), "Test message"),
                         receive
@@ -208,7 +206,7 @@ console_log_test_() ->
                         unregister(user),
                         register(user, Pid),
                         erlang:group_leader(Pid, whereis(lager_event)),
-                        gen_event:add_handler(lager_event, lager_console_backend, [{sink, lager_event}, info, true]),
+                        gen_event:add_handler(lager_event, lager_console_backend, [info, true]),
                         lager_config:set({lager_event, loglevel}, {element(2, lager_util:config_to_mask(info)), []}),
                         lager:info("Test message"),
                         PidStr = pid_to_list(self()),
@@ -229,7 +227,7 @@ console_log_test_() ->
                         register(user, Pid),
                         erlang:group_leader(Pid, whereis(lager_event)),
                         gen_event:add_handler(lager_event, lager_console_backend,
-                          [{sink, lager_event}, info, {lager_default_formatter, [date,"#",time,"#",severity,"#",node,"#",pid,"#",
+                          [info, {lager_default_formatter, [date,"#",time,"#",severity,"#",node,"#",pid,"#",
                                                             module,"#",function,"#",file,"#",line,"#",message,"\r\n"]}]),
                         lager_config:set({lager_event, loglevel}, {?INFO, []}),
                         lager:info("Test message"),
@@ -252,7 +250,7 @@ console_log_test_() ->
                         Pid = spawn(F(self())),
                         unregister(user),
                         register(user, Pid),
-                        gen_event:add_handler(lager_event, lager_console_backend, [{sink, lager_event}, info]),
+                        gen_event:add_handler(lager_event, lager_console_backend, info),
                         erlang:group_leader(Pid, whereis(lager_event)),
                         lager_config:set({lager_event, loglevel}, {element(2, lager_util:config_to_mask(info)), []}),
                         lager:debug("Test message"),
@@ -282,7 +280,7 @@ console_log_test_() ->
                         Pid = spawn(F(self())),
                         unregister(user),
                         register(user, Pid),
-                        gen_event:add_handler(lager_event, lager_console_backend, [{sink, lager_event}, info]),
+                        gen_event:add_handler(lager_event, lager_console_backend, info),
                         lager_config:set({lager_event, loglevel}, {element(2, lager_util:config_to_mask(info)), []}),
                         erlang:group_leader(Pid, whereis(lager_event)),
                         lager:debug("Test message"),
@@ -321,7 +319,7 @@ console_log_test_() ->
                         Pid = spawn(F(self())),
                         unregister(user),
                         register(user, Pid),
-                        gen_event:add_handler(lager_event, lager_console_backend, [{sink, lager_event}, info]),
+                        gen_event:add_handler(lager_event, lager_console_backend, info),
                         lager_config:set({lager_event, loglevel}, {element(2, lager_util:config_to_mask(info)), []}),
                         lager:set_loglevel(lager_console_backend, '!=info'),
                         erlang:group_leader(Pid, whereis(lager_event)),
@@ -352,7 +350,7 @@ console_log_test_() ->
                         Pid = spawn(F(self())),
                         unregister(user),
                         register(user, Pid),
-                        gen_event:add_handler(lager_event, lager_console_backend, [{sink, lager_event}, info]),
+                        gen_event:add_handler(lager_event, lager_console_backend, info),
                         lager_config:set({lager_event, loglevel}, {element(2, lager_util:config_to_mask(info)), []}),
                         lager:set_loglevel(lager_console_backend, '=debug'),
                         erlang:group_leader(Pid, whereis(lager_event)),

src/lager_file_backend.erl

@@ -80,8 +80,6 @@
                   {formatter_config, term()}.
 
 -spec init([option(),...]) -> {ok, #state{}} | {error, bad_config}.
-init([{sink, _Sink}|Options]) ->
-    init(Options);
 init({FileName, LogLevel}) when is_list(FileName), is_atom(LogLevel) ->
     %% backwards compatability hack
     init([{file, FileName}, {level, LogLevel}]);

src/lager_handler_watcher.erl

@@ -47,11 +47,8 @@ start_link(Sink, Module, Config) ->
 start(Sink, Module, Config) ->
     gen_server:start(?MODULE, [Sink, Module, Config], []).
 
-init([Sink, Module, Config]) when is_list(Config) ->
-    install_handler(Sink, Module, Config),
-    {ok, #state{sink=Sink, module=Module, config=Config}};
 init([Sink, Module, Config]) ->
-    install_handler(Sink, Module, [Config]),
+    install_handler(Sink, Module, Config),
     {ok, #state{sink=Sink, module=Module, config=Config}}.
 
 handle_call(_Call, _From, State) ->
@@ -90,9 +87,19 @@ code_change(_OldVsn, State, _Extra) ->
     {ok, State}.
 
 %% internal
-
+install_handler(Sink, lager_backend_throttle, Config) ->
+    %% The lager_backend_throttle needs to know to which sink it is
+    %% attached, hence this admittedly ugly workaround. Handlers are
+    %% sensitive to the structure of the configuration sent to `init',
+    %% sadly, so it's not trivial to add a configuration item to be
+    %% ignored to backends without breaking 3rd party handlers.
+    install_handler2(Sink, lager_backend_throttle, [{sink, Sink}|Config]);
 install_handler(Sink, Module, Config) ->
-    case gen_event:add_sup_handler(Sink, Module, [{sink, Sink}|Config]) of
+    install_handler2(Sink, Module, Config).
+
+%% private
+install_handler2(Sink, Module, Config) ->
+    case gen_event:add_sup_handler(Sink, Module, Config) of
         ok ->
             ?INT_LOG(debug, "Lager installed handler ~p into ~p", [Module, Sink]),
             lager:update_loglevel_config(Sink),

test/lager_crash_backend.erl

@@ -27,7 +27,7 @@
 -include_lib("eunit/include/eunit.hrl").
 -endif.
 
-init([{sink, _Sink}, CrashBefore, CrashAfter]) ->
+init([CrashBefore, CrashAfter]) ->
     case is_tuple(CrashBefore) andalso (timer:now_diff(CrashBefore, os:timestamp()) > 0) of
         true ->
             %?debugFmt("crashing!~n", []),

test/lager_test_backend.erl

@@ -35,8 +35,6 @@
 -export([pop/0, count/0, count_ignored/0, flush/0, print_state/0]).
 -endif.
 
-init([{sink, _Sink}, Level]) ->
-    init(Level);
 init(Level) ->
     {ok, #state{level=lager_util:config_to_mask(Level), buffer=[], ignored=[]}}.
 
@@ -150,11 +148,11 @@ lager_test_() ->
                         ?assertEqual(0, count())
                 end
             },
-	    {"test sink not running",
-		fun() ->
-			?assertEqual({error, {sink_not_configured, test}}, lager:log(test, info, self(), "~p", "not running"))
-		end
-	    },
+        {"test sink not running",
+        fun() ->
+            ?assertEqual({error, {sink_not_configured, test}}, lager:log(test, info, self(), "~p", "not running"))
+        end
+        },
             {"logging works",
                 fun() ->
                         lager:warning("test message"),
@@ -665,7 +663,7 @@ extra_sinks_test_() ->
                         ok
                 end
             }
-	]
+    ]
     }.
 
 setup_sink() ->