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345 | % %CopyrightBegin%
%
% | /¯\ /¯_ /¯_ |_¯ |¯\ (` | |\/| |¯\ | |_¯ | |
%\ |__ \_/ \_/ \_/ |__ |¯\ ___ \_) | | | |¯¯ |__ |__ ___ |¯| . E R L
%%
%% Copyright Ericsson AB 2017-2018. All Rights Reserved.
%%
%% Whitespace Beautified by ScriptCulture © JANUARY 2019
%% Sit Back · Feet Up · Learn Erlang ¯¯¯¯¯¯¯
%% For use as a reference only
%% www.scriptculture.com
%% Not check-summed
%% kernel-6.1.1
%%
%% 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 => erlang:system_time ( microsecond )
}}
)
,
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 => erlang:system_time(microsecond)}
}]
.
%%%-----------------------------------------------------------------
%%% 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).
|