%%
%% %CopyrightBegin%
%%
%% Copyright Ericsson AB 1998-2013. 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(nteventlog).
-behaviour(gen_server).
%% API
-export([start_link/2, start/2, stop/0]).
%% gen_server callbacks
-export([init/1, handle_call/3, handle_cast/2, handle_info/2,
terminate/2, code_change/3]).
-record(state, {port, mfa}).
%%----------------------------------------------------------------------
%% API
%%----------------------------------------------------------------------
start_link(Ident, MFA) ->
gen_server:start_link({local, nteventlog}, nteventlog,
[Ident, MFA], []).
start(Ident, MFA) ->
gen_server:start({local, nteventlog}, nteventlog, [Ident, MFA], []).
stop() ->
gen_server:call(nteventlog, stop).
%%----------------------------------------------------------------------
%% gen_server callbacks
%%----------------------------------------------------------------------
init([Identifier,MFA0]) ->
process_flag(trap_exit, true),
process_flag(priority, low),
Port = case os:type() of
{win32, _OSname} -> start_portprogram(Identifier);
OS -> exit({unsupported_os, OS})
end,
%% If we're using os_sup:error_report/2,
%% the setting of os_sup_errortag should be used as argument
MFA = case MFA0 of
{os_sup, error_report, [_Tag]} ->
Tag = os_mon:get_env(os_sup, os_sup_errortag),
{os_sup, error_report, [Tag]};
_ ->
MFA0
end,
{ok, #state{port=Port, mfa=MFA}}.
handle_call(stop, _From, State) ->
{stop, normal, stopped, State}.
handle_cast(_Msg, State) ->
{noreply, State}.
handle_info({_Port, {data, Data}}, #state{mfa={M,F,A}} = State) ->
T = parse_log(Data),
apply(M, F, [T | A]),
State#state.port ! {self(), {command, "A"}},
{noreply, State};
handle_info({'EXIT', _Port, Reason}, State) ->
{stop, {port_died, Reason}, State#state{port=not_used}};
handle_info(_Info, State) ->
{noreply, State}.
terminate(_Reason, State) ->
case State#state.port of
not_used -> ignore;
Port ->
port_close(Port)
end,
ok.
%% os_mon-2.0
%% For live downgrade to/upgrade from os_mon-1.8[.1]
code_change(Vsn, PrevState, "1.8") ->
case Vsn of
%% Downgrade from this version
{down, _Vsn} ->
process_flag(trap_exit, false),
%% Downgrade to old State tuple
State = {PrevState#state.port, PrevState#state.mfa},
{ok, State};
%% Upgrade to this version
_Vsn ->
process_flag(trap_exit, true),
%% Upgrade to this state record
{Port, MFA} = PrevState,
State = #state{port=Port, mfa=MFA},
{ok, State}
end;
code_change(_OldVsn, State, _Extra) ->
{ok, State}.
%%----------------------------------------------------------------------
%% Internal functions
%%----------------------------------------------------------------------
start_portprogram(Identifier) ->
Command =
"\"" ++ filename:join([code:priv_dir(os_mon),"bin","nteventlog.exe"]) ++
"\" " ++ make_list(Identifier),
open_port({spawn,Command},[{packet,2}]).
make_list(X) when is_atom(X) ->
atom_to_list(X);
make_list(X) ->
X.
holl_len([$H | Rest], Sum) ->
{Sum, Rest};
holl_len([ N | Rest], Sum) ->
NN = N - $0,
holl_len(Rest, Sum * 10 + NN).
holl_len(L) ->
holl_len(L,0).
splitlist(L,N) ->
{lists:sublist(L,N),lists:nthtail(N,L)}.
hollerith(Str) ->
{Len, Rest} = holl_len(Str),
splitlist(Rest,Len).
holl_time(Str) ->
{Holl,Rest} = hollerith(Str),
Rev = lists:reverse(Holl),
B = list_to_integer(lists:reverse(lists:sublist(Rev,6))),
A = list_to_integer(lists:reverse(lists:nthtail(6,Rev))),
{{A,B,0},Rest}.
parse_log(Str) ->
{Time, Rest1} = holl_time(Str),
{Category,Rest2} = hollerith(Rest1),
{Facility,Rest3} = hollerith(Rest2),
{Severity,Rest4} = hollerith(Rest3),
{Message,_} = hollerith(Rest4),
{Time,Category,Facility,Severity,Message}.
