diff options
Diffstat (limited to 'lib/kernel/src/logger_simple_h.erl')
| -rw-r--r-- | lib/kernel/src/logger_simple_h.erl | 215 |
1 files changed, 215 insertions, 0 deletions
diff --git a/lib/kernel/src/logger_simple_h.erl b/lib/kernel/src/logger_simple_h.erl new file mode 100644 index 0000000000..a0d51dba25 --- /dev/null +++ b/lib/kernel/src/logger_simple_h.erl @@ -0,0 +1,215 @@ +%% +%% %CopyrightBegin% +%% +%% Copyright Ericsson AB 2017-2018. All Rights Reserved. +%% +%% Licensed 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. +%% +%% %CopyrightEnd% +%% +-module(logger_simple_h). + +-export([adding_handler/1, removing_handler/1, log/2]). + +%% This module implements a simple handler for logger. It is the +%% default used during system start. + +%%%----------------------------------------------------------------- +%%% Logger callback + +adding_handler(#{id:=simple}=Config) -> + Me = self(), + case whereis(?MODULE) of + undefined -> + {Pid,Ref} = spawn_opt(fun() -> init(Me) end, + [link,monitor,{message_queue_data,off_heap}]), + receive + {'DOWN',Ref,process,Pid,Reason} -> + {error,Reason}; + {Pid,started} -> + erlang:demonitor(Ref), + {ok,Config} + end; + _ -> + {error,{handler_process_name_already_exists,?MODULE}} + end. + +removing_handler(#{id:=simple}) -> + case whereis(?MODULE) of + undefined -> + ok; + Pid -> + Ref = erlang:monitor(process,Pid), + Pid ! stop, + receive {'DOWN',Ref,process,Pid,_} -> + ok + end + end. + +log(#{meta:=#{error_logger:=#{tag:=info_report,type:=Type}}},_Config) + when Type=/=std_info -> + %% Skip info reports that are not 'std_info' (ref simple logger in + %% error_logger) + ok; +log(#{msg:=_,meta:=#{time:=_}}=Log,_Config) -> + _ = case whereis(?MODULE) of + undefined -> + %% Is the node on the way down? Real emergency? + %% Log directly from client just to get it out + do_log( + #{level=>error, + msg=>{report,{error,simple_handler_process_dead}}, + meta=>#{time=>logger:timestamp()}}), + do_log(Log); + _ -> + ?MODULE ! {log,Log} + end, + ok; +log(_,_) -> + %% Unexpected log. + %% We don't want to crash the simple logger, so ignore this. + ok. + +%%%----------------------------------------------------------------- +%%% Process +init(Starter) -> + register(?MODULE,self()), + Starter ! {self(),started}, + loop(#{buffer_size=>10,dropped=>0,buffer=>[]}). + +loop(Buffer) -> + receive + stop -> + %% We replay the logger messages of there is + %% a default handler when the simple handler + %% is removed. + case logger:get_handler_config(default) of + {ok, _} -> + replay_buffer(Buffer); + _ -> + ok + end, + %% Before stopping, we unlink the logger process to avoid + %% an unexpected EXIT message + unlink(whereis(logger)), + ok; + {log,#{msg:=_,meta:=#{time:=_}}=Log} -> + do_log(Log), + loop(update_buffer(Buffer,Log)); + _ -> + %% Unexpected message - flush it! + loop(Buffer) + end. + +update_buffer(#{buffer_size:=0,dropped:=D}=Buffer,_Log) -> + Buffer#{dropped=>D+1}; +update_buffer(#{buffer_size:=S,buffer:=B}=Buffer,Log) -> + Buffer#{buffer_size=>S-1,buffer=>[Log|B]}. + +replay_buffer(#{ dropped := D, buffer := Buffer }) -> + lists:foreach( + fun F(#{msg := {Tag, Msg}} = L) when Tag =:= string; Tag =:= report -> + F(L#{ msg := Msg }); + F(#{ level := Level, msg := Msg, meta := MD}) -> + logger:log(Level, Msg, MD) + end, lists:reverse(Buffer, drop_msg(D))). + +drop_msg(0) -> + []; +drop_msg(N) -> + [#{level=>info, + msg=>{"Simple handler buffer full, dropped ~w messages",[N]}, + meta=>#{time=>logger:timestamp()}}]. + +%%%----------------------------------------------------------------- +%%% Internal + +%% Can't do io_lib:format + +do_log(#{msg:={report,Report}, + meta:=#{time:=T,error_logger:=#{type:=Type}}}) -> + display_date(T), + display_report(Type,Report); +do_log(#{msg:=Msg,meta:=#{time:=T}}) -> + display_date(T), + display(Msg). + +display_date(Timestamp) when is_integer(Timestamp) -> + Micro = Timestamp rem 1000000, + Sec = Timestamp div 1000000, + {{Y,Mo,D},{H,Mi,S}} = erlang:universaltime_to_localtime( + erlang:posixtime_to_universaltime(Sec)), + erlang:display_string( + integer_to_list(Y) ++ "-" ++ + pad(Mo,2) ++ "-" ++ + pad(D,2) ++ " " ++ + pad(H,2) ++ ":" ++ + pad(Mi,2) ++ ":" ++ + pad(S,2) ++ "." ++ + pad(Micro,6) ++ " "). + +pad(Int,Size) when is_integer(Int) -> + pad(integer_to_list(Int),Size); +pad(Str,Size) when length(Str)==Size -> + Str; +pad(Str,Size) -> + pad([$0|Str],Size). + +display({string,Chardata}) -> + try unicode:characters_to_list(Chardata) of + String -> erlang:display_string(String), erlang:display_string("\n") + catch _:_ -> erlang:display(Chardata) + end; +display({report,Report}) when is_map(Report) -> + display_report(maps:to_list(Report)); +display({report,Report}) -> + display_report(Report); +display({F, A}) when is_list(F), is_list(A) -> + erlang:display_string(F ++ "\n"), + [begin + erlang:display_string("\t"), + erlang:display(Arg) + end || Arg <- A], + ok. + +display_report(Atom, A) when is_atom(Atom) -> + %% The widest atom seems to be 'supervisor_report' at 17. + ColumnWidth = 20, + AtomString = atom_to_list(Atom), + AtomLength = length(AtomString), + Padding = lists:duplicate(ColumnWidth - AtomLength, $\s), + erlang:display_string(AtomString ++ Padding), + display_report(A); +display_report(F, A) -> + erlang:display({F, A}). + +display_report([A, []]) -> + %% Special case for crash reports when process has no links + display_report(A); +display_report(A = [_|_]) -> + case lists:all(fun({Key,_Value}) -> is_atom(Key); (_) -> false end, A) of + true -> + erlang:display_string("\n"), + lists:foreach( + fun({Key, Value}) -> + erlang:display_string( + " " ++ + atom_to_list(Key) ++ + ": "), + erlang:display(Value) + end, A); + false -> + erlang:display(A) + end; +display_report(A) -> + erlang:display(A). |