src/error_logger_lager_h.erl - couchdb-lager - Git at Google

 %% Copyright (c) 2011 Basho Technologies, Inc.  All Rights Reserved.
 %%
 %% This file is provided to you under the Apache License,
 %% Version 2.0 (the "License"); you may not use this file
 %% except in compliance with the License.  You may obtain
 %% a copy of the License at
 %%
 %%   http://www.apache.org/licenses/LICENSE-2.0
 %%
 %% Unless required by applicable law or agreed to in writing,
 %% software distributed under the License is distributed on an
 %% "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
 %% KIND, either express or implied.  See the License for the
 %% specific language governing permissions and limitations
 %% under the License.

 %% @doc A error_logger backend for redirecting events into lager.
 %% Error messages and crash logs are also optionally written to a crash log.

 %% @see lager_crash_log

 %% @private

 -module(error_logger_lager_h).

 -include("lager.hrl").

 -behaviour(gen_event).

 -export([init/1, handle_call/2, handle_event/2, handle_info/2, terminate/2,
         code_change/3]).

 -export([format_reason/1]).

 -define(LOG(Level, Pid, Msg),
     case ?SHOULD_LOG(Level) of
         true ->
             lager:log(Level, Pid, Msg);
         _ -> ok
     end).

 -define(LOG(Level, Pid, Fmt, Args),
     case ?SHOULD_LOG(Level) of
         true ->
             lager:log(Level, Pid, Fmt, Args);
         _ -> ok
     end).

 -define(CRASH_LOG(Event),
     gen_server:cast(lager_crash_log, {log, Event})).

 -spec init(any()) -> {ok, {}}.
 init(_) ->
     {ok, {}}.

 handle_call(_Request, State) ->
     {ok, ok, State}.

 handle_event(Event, State) ->
     case Event of
         {error, _GL, {Pid, Fmt, Args}} ->
             case Fmt of
                 "** Generic server "++_ ->
                     %% gen_server terminate
                     [Name, _Msg, _State, Reason] = Args,
                     ?CRASH_LOG(Event),
                     ?LOG(error, Pid, "gen_server ~w terminated with reason: ~s",
                         [Name, format_reason(Reason)]);
                 "** State machine "++_ ->
                     %% gen_fsm terminate
                     [Name, _Msg, StateName, _StateData, Reason] = Args,
                     ?CRASH_LOG(Event),
                     ?LOG(error, Pid, "gen_fsm ~w in state ~w terminated with reason: ~s",
                         [Name, StateName, format_reason(Reason)]);
                 "** gen_event handler"++_ ->
                     %% gen_event handler terminate
                     [ID, Name, _Msg, _State, Reason] = Args,
                     ?CRASH_LOG(Event),
                     ?LOG(error, Pid, "gen_event ~w installed in ~w terminated with reason: ~s",
                         [ID, Name, format_reason(Reason)]);
                 _ ->
                     ?CRASH_LOG(Event),
                     ?LOG(error, Pid, lager:safe_format(Fmt, Args, 4096))
             end;
         {error_report, _GL, {Pid, std_error, D}} ->
             ?CRASH_LOG(Event),
             ?LOG(error, Pid, print_silly_list(D));
         {error_report, _GL, {Pid, supervisor_report, D}} ->
             ?CRASH_LOG(Event),
             case lists:sort(D) of
                 [{errorContext, Ctx}, {offender, Off}, {reason, Reason}, {supervisor, Name}] ->
                     Offender = format_offender(Off),
                     ?LOG(error, Pid,
                         "Supervisor ~w had child ~s exit with reason ~s in context ~w",
                         [element(2, Name), Offender, format_reason(Reason), Ctx]);
                 _ ->
                     ?LOG(error, Pid, ["SUPERVISOR REPORT ", print_silly_list(D)])
             end;
         {error_report, _GL, {Pid, crash_report, [Self, Neighbours]}} ->
             ?CRASH_LOG(Event),
             ?LOG(error, Pid, ["CRASH REPORT ", format_crash_report(Self, Neighbours)]);
         {warning_msg, _GL, {Pid, Fmt, Args}} ->
             ?LOG(warning, Pid, lager:safe_format(Fmt, Args, 4096));
         {warning_report, _GL, {Pid, std_warning, Report}} ->
             ?LOG(warning, Pid, print_silly_list(Report));
         {info_msg, _GL, {Pid, Fmt, Args}} ->
             ?LOG(info, Pid, lager:safe_format(Fmt, Args, 4096));
         {info_report, _GL, {Pid, std_info, D}} when is_list(D) ->
             Details = lists:sort(D),
             case Details of
                 [{application, App}, {exited, Reason}, {type, _Type}] ->
                     ?LOG(info, Pid, "Application ~w exited with reason: ~s",
                         [App, format_reason(Reason)]);
                 _ ->
                     ?LOG(info, Pid, print_silly_list(D))
             end;
         {info_report, _GL, {Pid, std_info, D}} ->
             ?LOG(info, Pid, "~w", [D]);
         {info_report, _GL, {P, progress, D}} ->
             Details = lists:sort(D),
             case Details of
                 [{application, App}, {started_at, Node}] ->
                     ?LOG(info, P, "Application ~w started on node ~w",
                         [App, Node]);
                 [{started, Started}, {supervisor, Name}] ->
                     MFA = format_mfa(proplists:get_value(mfargs, Started)),
                     Pid = proplists:get_value(pid, Started),
                     ?LOG(debug, P, "Supervisor ~w started ~s at pid ~w",
                         [element(2, Name), MFA, Pid]);
                 _ ->
                     ?LOG(info, P, ["PROGRESS REPORT ", print_silly_list(D)])
             end;
         _ ->
             ?LOG(warning, self(), "Unexpected error_logger event ~w", [Event])
     end,
     {ok, State}.

 handle_info(_Info, State) ->
     {ok, State}.

 terminate(_Reason, _State) ->
     ok.

 code_change(_OldVsn, State, _Extra) ->
     {ok, State}.

 %% internal functions

 format_crash_report(Report, Neighbours) ->
     Name = proplists:get_value(registered_name, Report, proplists:get_value(pid, Report)),
     {_Class, Reason, _Trace} = proplists:get_value(error_info, Report),
     io_lib:format("Process ~w with ~w neighbours crashed with reason: ~s",
         [Name, length(Neighbours), format_reason(Reason)]).

 format_offender(Off) ->
     case proplists:get_value(mfargs, Off) of
         undefined ->
             %% supervisor_bridge
             io_lib:format("at module ~w at ~w",
                 [proplists:get_value(mod, Off), proplists:get_value(pid, Off)]);
         MFArgs ->
             %% regular supervisor
             MFA = format_mfa(MFArgs),
             Name = proplists:get_value(name, Off),
             io_lib:format("~w started with ~s at ~w",
                 [Name, MFA, proplists:get_value(pid, Off)])
     end.

 format_reason({'function not exported', [{M, F, A},MFA|_]}) ->
     ["call to undefined function ", format_mfa({M, F, length(A)}),
         " from ", format_mfa(MFA)];
 format_reason({undef, [MFA|_]}) ->
     ["call to undefined function ", format_mfa(MFA)];
 format_reason({bad_return_value, Val}) ->
     ["bad return value: ", print_val(Val)];
 format_reason({{bad_return_value, Val}, MFA}) ->
     ["bad return value: ", print_val(Val), " in ", format_mfa(MFA)];
 format_reason({{case_clause, Val}, [MFA|_]}) ->
     ["no case clause matching ", print_val(Val), " in ", format_mfa(MFA)];
 format_reason({function_clause, [MFA|_]}) ->
     ["no function clause matching ", format_mfa(MFA)];
 format_reason({if_clause, [MFA|_]}) ->
     ["no true branch found while evaluating if expression in ", format_mfa(MFA)];
 format_reason({{try_clause, Val}, [MFA|_]}) ->
     ["no try clause matching ", print_val(Val), " in ", format_mfa(MFA)];
 format_reason({badarith, [MFA|_]}) ->
     ["bad arithmetic expression in ", format_mfa(MFA)];
 format_reason({{badmatch, Val}, [MFA|_]}) ->
     ["no match of right hand value ", print_val(Val), " in ", format_mfa(MFA)];
 format_reason({emfile, _Trace}) ->
     "maximum number of file descriptors exhausted, check ulimit -n";
 format_reason({system_limit, [{M, F, _}|_] = Trace}) ->
     Limit = case {M, F} of
         {erlang, open_port} ->
             "maximum number of ports exceeded";
         {erlang, spawn} ->
             "maximum number of processes exceeded";
         {erlang, spawn_opt} ->
             "maximum number of processes exceeded";
         {erlang, list_to_atom} ->
             "tried to create an atom larger than 255, or maximum atom count exceeded";
         {ets, new} ->
             "maximum number of ETS tables exceeded";
         _ ->
             {Str, _} = lager_trunc_io:print(Trace, 500),
             Str
     end,
     ["system limit: ", Limit];
 format_reason({badarg, [MFA,MFA2|_]}) ->
     case MFA of
         {_M, _F, A} when is_list(A) ->
             ["bad argument in call to ", format_mfa(MFA), " in ", format_mfa(MFA2)];
         _ ->
             %% seems to be generated by a bad call to a BIF
             ["bad argument in ", format_mfa(MFA)]
     end;
 format_reason({{badarity, {Fun, Args}}, [MFA|_]}) ->
     {arity, Arity} = lists:keyfind(arity, 1, erlang:fun_info(Fun)),
     [io_lib:format("fun called with wrong arity of ~w instead of ~w in ",
             [length(Args), Arity]), format_mfa(MFA)];
 format_reason({noproc, MFA}) ->
     ["no such process or port in call to ", format_mfa(MFA)];
 format_reason({{badfun, Term}, [MFA|_]}) ->
     ["bad function ", print_val(Term), " in ", format_mfa(MFA)];
 format_reason(Reason) ->
     {Str, _} = lager_trunc_io:print(Reason, 500),
     Str.

 format_mfa({M, F, A}) when is_list(A) ->
     {FmtStr, Args} = format_args(A, [], []),
     io_lib:format("~w:~w("++FmtStr++")", [M, F | Args]);
 format_mfa({M, F, A}) when is_integer(A) ->
     io_lib:format("~w:~w/~w", [M, F, A]);
 format_mfa(Other) ->
     io_lib:format("~w", [Other]).

 format_args([], FmtAcc, ArgsAcc) ->
     {string:join(lists:reverse(FmtAcc), ", "), lists:reverse(ArgsAcc)};
 format_args([H|T], FmtAcc, ArgsAcc) ->
     {Str, _} = lager_trunc_io:print(H, 100),
     format_args(T, ["~s"|FmtAcc], [Str|ArgsAcc]).

 print_silly_list(L) when is_list(L) ->
     case lager_stdlib:string_p(L) of
         true ->
             lager_trunc_io:format("~s", [L], 4096);
         _ ->
             print_silly_list(L, [], [])
     end;
 print_silly_list(L) ->
     {Str, _} = lager_trunc_io:print(L, 4096),
     Str.

 print_silly_list([], Fmt, Acc) ->
     lager_trunc_io:format(string:join(lists:reverse(Fmt), ", "),
         lists:reverse(Acc), 4096);
 print_silly_list([{K,V}|T], Fmt, Acc) ->
     print_silly_list(T, ["~w: ~w" | Fmt], [V, K | Acc]);
 print_silly_list([H|T], Fmt, Acc) ->
     print_silly_list(T, ["~w" | Fmt], [H | Acc]).

 print_val(Val) ->
     {Str, _} = lager_trunc_io:print(Val, 500),
     Str.
	%% Copyright (c) 2011 Basho Technologies, Inc. All Rights Reserved.
	%%
	%% This file is provided to you under the Apache License,
	%% Version 2.0 (the "License"); you may not use this file
	%% except in compliance with the License. You may obtain
	%% a copy of the License at
	%%
	%% http://www.apache.org/licenses/LICENSE-2.0
	%%
	%% Unless required by applicable law or agreed to in writing,
	%% software distributed under the License is distributed on an
	%% "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
	%% KIND, either express or implied. See the License for the
	%% specific language governing permissions and limitations
	%% under the License.

	%% @doc A error_logger backend for redirecting events into lager.
	%% Error messages and crash logs are also optionally written to a crash log.

	%% @see lager_crash_log

	%% @private

	-module(error_logger_lager_h).

	-include("lager.hrl").

	-behaviour(gen_event).

	-export([init/1, handle_call/2, handle_event/2, handle_info/2, terminate/2,
	code_change/3]).

	-export([format_reason/1]).

	-define(LOG(Level, Pid, Msg),
	case ?SHOULD_LOG(Level) of
	true ->
	lager:log(Level, Pid, Msg);
	_ -> ok
	end).

	-define(LOG(Level, Pid, Fmt, Args),
	case ?SHOULD_LOG(Level) of
	true ->
	lager:log(Level, Pid, Fmt, Args);
	_ -> ok
	end).

	-define(CRASH_LOG(Event),
	gen_server:cast(lager_crash_log, {log, Event})).

	-spec init(any()) -> {ok, {}}.
	init(_) ->
	{ok, {}}.

	handle_call(_Request, State) ->
	{ok, ok, State}.

	handle_event(Event, State) ->
	case Event of
	{error, _GL, {Pid, Fmt, Args}} ->
	case Fmt of
	"** Generic server "++_ ->
	%% gen_server terminate
	[Name, _Msg, _State, Reason] = Args,
	?CRASH_LOG(Event),
	?LOG(error, Pid, "gen_server ~w terminated with reason: ~s",
	[Name, format_reason(Reason)]);
	"** State machine "++_ ->
	%% gen_fsm terminate
	[Name, _Msg, StateName, _StateData, Reason] = Args,
	?CRASH_LOG(Event),
	?LOG(error, Pid, "gen_fsm ~w in state ~w terminated with reason: ~s",
	[Name, StateName, format_reason(Reason)]);
	"** gen_event handler"++_ ->
	%% gen_event handler terminate
	[ID, Name, _Msg, _State, Reason] = Args,
	?CRASH_LOG(Event),
	?LOG(error, Pid, "gen_event ~w installed in ~w terminated with reason: ~s",
	[ID, Name, format_reason(Reason)]);
	_ ->
	?CRASH_LOG(Event),
	?LOG(error, Pid, lager:safe_format(Fmt, Args, 4096))
	end;
	{error_report, _GL, {Pid, std_error, D}} ->
	?CRASH_LOG(Event),
	?LOG(error, Pid, print_silly_list(D));
	{error_report, _GL, {Pid, supervisor_report, D}} ->
	?CRASH_LOG(Event),
	case lists:sort(D) of
	[{errorContext, Ctx}, {offender, Off}, {reason, Reason}, {supervisor, Name}] ->
	Offender = format_offender(Off),
	?LOG(error, Pid,
	"Supervisor ~w had child ~s exit with reason ~s in context ~w",
	[element(2, Name), Offender, format_reason(Reason), Ctx]);
	_ ->
	?LOG(error, Pid, ["SUPERVISOR REPORT ", print_silly_list(D)])
	end;
	{error_report, _GL, {Pid, crash_report, [Self, Neighbours]}} ->
	?CRASH_LOG(Event),
	?LOG(error, Pid, ["CRASH REPORT ", format_crash_report(Self, Neighbours)]);
	{warning_msg, _GL, {Pid, Fmt, Args}} ->
	?LOG(warning, Pid, lager:safe_format(Fmt, Args, 4096));
	{warning_report, _GL, {Pid, std_warning, Report}} ->
	?LOG(warning, Pid, print_silly_list(Report));
	{info_msg, _GL, {Pid, Fmt, Args}} ->
	?LOG(info, Pid, lager:safe_format(Fmt, Args, 4096));
	{info_report, _GL, {Pid, std_info, D}} when is_list(D) ->
	Details = lists:sort(D),
	case Details of
	[{application, App}, {exited, Reason}, {type, _Type}] ->
	?LOG(info, Pid, "Application ~w exited with reason: ~s",
	[App, format_reason(Reason)]);
	_ ->
	?LOG(info, Pid, print_silly_list(D))
	end;
	{info_report, _GL, {Pid, std_info, D}} ->
	?LOG(info, Pid, "~w", [D]);
	{info_report, _GL, {P, progress, D}} ->
	Details = lists:sort(D),
	case Details of
	[{application, App}, {started_at, Node}] ->
	?LOG(info, P, "Application ~w started on node ~w",
	[App, Node]);
	[{started, Started}, {supervisor, Name}] ->
	MFA = format_mfa(proplists:get_value(mfargs, Started)),
	Pid = proplists:get_value(pid, Started),
	?LOG(debug, P, "Supervisor ~w started ~s at pid ~w",
	[element(2, Name), MFA, Pid]);
	_ ->
	?LOG(info, P, ["PROGRESS REPORT ", print_silly_list(D)])
	end;
	_ ->
	?LOG(warning, self(), "Unexpected error_logger event ~w", [Event])
	end,
	{ok, State}.

	handle_info(_Info, State) ->
	{ok, State}.

	terminate(_Reason, _State) ->
	ok.

	code_change(_OldVsn, State, _Extra) ->
	{ok, State}.

	%% internal functions

	format_crash_report(Report, Neighbours) ->
	Name = proplists:get_value(registered_name, Report, proplists:get_value(pid, Report)),
	{_Class, Reason, _Trace} = proplists:get_value(error_info, Report),
	io_lib:format("Process ~w with ~w neighbours crashed with reason: ~s",
	[Name, length(Neighbours), format_reason(Reason)]).

	format_offender(Off) ->
	case proplists:get_value(mfargs, Off) of
	undefined ->
	%% supervisor_bridge
	io_lib:format("at module ~w at ~w",
	[proplists:get_value(mod, Off), proplists:get_value(pid, Off)]);
	MFArgs ->
	%% regular supervisor
	MFA = format_mfa(MFArgs),
	Name = proplists:get_value(name, Off),
	io_lib:format("~w started with ~s at ~w",
	[Name, MFA, proplists:get_value(pid, Off)])
	end.

	format_reason({'function not exported', [{M, F, A},MFA\|_]}) ->
	["call to undefined function ", format_mfa({M, F, length(A)}),
	" from ", format_mfa(MFA)];
	format_reason({undef, [MFA\|_]}) ->
	["call to undefined function ", format_mfa(MFA)];
	format_reason({bad_return_value, Val}) ->
	["bad return value: ", print_val(Val)];
	format_reason({{bad_return_value, Val}, MFA}) ->
	["bad return value: ", print_val(Val), " in ", format_mfa(MFA)];
	format_reason({{case_clause, Val}, [MFA\|_]}) ->
	["no case clause matching ", print_val(Val), " in ", format_mfa(MFA)];
	format_reason({function_clause, [MFA\|_]}) ->
	["no function clause matching ", format_mfa(MFA)];
	format_reason({if_clause, [MFA\|_]}) ->
	["no true branch found while evaluating if expression in ", format_mfa(MFA)];
	format_reason({{try_clause, Val}, [MFA\|_]}) ->
	["no try clause matching ", print_val(Val), " in ", format_mfa(MFA)];
	format_reason({badarith, [MFA\|_]}) ->
	["bad arithmetic expression in ", format_mfa(MFA)];
	format_reason({{badmatch, Val}, [MFA\|_]}) ->
	["no match of right hand value ", print_val(Val), " in ", format_mfa(MFA)];
	format_reason({emfile, _Trace}) ->
	"maximum number of file descriptors exhausted, check ulimit -n";
	format_reason({system_limit, [{M, F, _}\|_] = Trace}) ->
	Limit = case {M, F} of
	{erlang, open_port} ->
	"maximum number of ports exceeded";
	{erlang, spawn} ->
	"maximum number of processes exceeded";
	{erlang, spawn_opt} ->
	"maximum number of processes exceeded";
	{erlang, list_to_atom} ->
	"tried to create an atom larger than 255, or maximum atom count exceeded";
	{ets, new} ->
	"maximum number of ETS tables exceeded";
	_ ->
	{Str, _} = lager_trunc_io:print(Trace, 500),
	Str
	end,
	["system limit: ", Limit];
	format_reason({badarg, [MFA,MFA2\|_]}) ->
	case MFA of
	{_M, _F, A} when is_list(A) ->
	["bad argument in call to ", format_mfa(MFA), " in ", format_mfa(MFA2)];
	_ ->
	%% seems to be generated by a bad call to a BIF
	["bad argument in ", format_mfa(MFA)]
	end;
	format_reason({{badarity, {Fun, Args}}, [MFA\|_]}) ->
	{arity, Arity} = lists:keyfind(arity, 1, erlang:fun_info(Fun)),
	[io_lib:format("fun called with wrong arity of ~w instead of ~w in ",
	[length(Args), Arity]), format_mfa(MFA)];
	format_reason({noproc, MFA}) ->
	["no such process or port in call to ", format_mfa(MFA)];
	format_reason({{badfun, Term}, [MFA\|_]}) ->
	["bad function ", print_val(Term), " in ", format_mfa(MFA)];
	format_reason(Reason) ->
	{Str, _} = lager_trunc_io:print(Reason, 500),
	Str.

	format_mfa({M, F, A}) when is_list(A) ->
	{FmtStr, Args} = format_args(A, [], []),
	io_lib:format("~w:~w("++FmtStr++")", [M, F \| Args]);
	format_mfa({M, F, A}) when is_integer(A) ->
	io_lib:format("~w:~w/~w", [M, F, A]);
	format_mfa(Other) ->
	io_lib:format("~w", [Other]).

	format_args([], FmtAcc, ArgsAcc) ->
	{string:join(lists:reverse(FmtAcc), ", "), lists:reverse(ArgsAcc)};
	format_args([H\|T], FmtAcc, ArgsAcc) ->
	{Str, _} = lager_trunc_io:print(H, 100),
	format_args(T, ["~s"\|FmtAcc], [Str\|ArgsAcc]).

	print_silly_list(L) when is_list(L) ->
	case lager_stdlib:string_p(L) of
	true ->
	lager_trunc_io:format("~s", [L], 4096);
	_ ->
	print_silly_list(L, [], [])
	end;
	print_silly_list(L) ->
	{Str, _} = lager_trunc_io:print(L, 4096),
	Str.

	print_silly_list([], Fmt, Acc) ->
	lager_trunc_io:format(string:join(lists:reverse(Fmt), ", "),
	lists:reverse(Acc), 4096);
	print_silly_list([{K,V}\|T], Fmt, Acc) ->
	print_silly_list(T, ["~w: ~w" \| Fmt], [V, K \| Acc]);
	print_silly_list([H\|T], Fmt, Acc) ->
	print_silly_list(T, ["~w" \| Fmt], [H \| Acc]).

	print_val(Val) ->
	{Str, _} = lager_trunc_io:print(Val, 500),
	Str.