%%%----------------------------------------------------------------------
%%% File : gen_mod.erl
%%% Author : Alexey Shchepin <alexey@process-one.net>
%%% Purpose :
%%% Purpose :
%%% Created : 24 Jan 2003 by Alexey Shchepin <alexey@process-one.net>
%%%
%%%
%%% ejabberd, Copyright (C) 2002-2013 ProcessOne
%%%
%%% This program is free software; you can redistribute it and/or
%%% modify it under the terms of the GNU General Public License as
%%% published by the Free Software Foundation; either version 2 of the
%%% License, or (at your option) any later version.
%%%
%%% This program is distributed in the hope that it will be useful,
%%% but WITHOUT ANY WARRANTY; without even the implied warranty of
%%% MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
%%% General Public License for more details.
%%%
%%% You should have received a copy of the GNU General Public License
%%% along with this program; if not, write to the Free Software
%%% Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
%%% 02111-1307 USA
%%%
%%%----------------------------------------------------------------------
-module(gen_mod).
-author('alexey@process-one.net').
-export([start/0, start_module/3, stop_module/2,
stop_module_keep_config/2, get_opt/3, get_opt/4,
get_opt_host/3, db_type/1, db_type/2, get_module_opt/5,
get_module_opt_host/3, loaded_modules/1,
loaded_modules_with_opts/1, get_hosts/2,
get_module_proc/2, is_loaded/2]).
%%-export([behaviour_info/1]).
-include("ejabberd.hrl").
-include("logger.hrl").
-record(ejabberd_module,
{module_host = {undefined, <<"">>} :: {atom(), binary()},
opts = [] :: opts() | '_' | '$2'}).
-type opts() :: [{atom(), any()}].
-callback start(binary(), opts()) -> any().
-callback stop(binary()) -> any().
-export_type([opts/0]).
%%behaviour_info(callbacks) -> [{start, 2}, {stop, 1}];
%%behaviour_info(_Other) -> undefined.
start() ->
ets:new(ejabberd_modules,
[named_table, public,
{keypos, #ejabberd_module.module_host}]),
ok.
-spec start_module(binary(), atom(), opts()) -> any().
start_module(Host, Module, Opts) ->
set_module_opts_mnesia(Host, Module, Opts),
ets:insert(ejabberd_modules,
#ejabberd_module{module_host = {Module, Host},
opts = Opts}),
try Module:start(Host, Opts) catch
Class:Reason ->
del_module_mnesia(Host, Module),
ets:delete(ejabberd_modules, {Module, Host}),
ErrorText =
io_lib:format("Problem starting the module ~p for host "
"~p ~n options: ~p~n ~p: ~p~n~p",
[Module, Host, Opts, Class, Reason,
erlang:get_stacktrace()]),
?CRITICAL_MSG(ErrorText, []),
case is_app_running(ejabberd) of
true ->
erlang:raise(Class, Reason, erlang:get_stacktrace());
false ->
?CRITICAL_MSG("ejabberd initialization was aborted "
"because a module start failed.",
[]),
timer:sleep(3000),
erlang:halt(string:substr(lists:flatten(ErrorText), 1, 199))
end
end.
is_app_running(AppName) ->
Timeout = 15000,
lists:keymember(AppName, 1,
application:which_applications(Timeout)).
-spec stop_module(binary(), atom()) -> error | {aborted, any()} | {atomic, any()}.
%% @doc Stop the module in a host, and forget its configuration.
stop_module(Host, Module) ->
case stop_module_keep_config(Host, Module) of
error -> error;
ok -> del_module_mnesia(Host, Module)
end.
%% @doc Stop the module in a host, but keep its configuration.
%% As the module configuration is kept in the Mnesia local_config table,
%% when ejabberd is restarted the module will be started again.
%% This function is useful when ejabberd is being stopped
%% and it stops all modules.
-spec stop_module_keep_config(binary(), atom()) -> error | ok.
stop_module_keep_config(Host, Module) ->
case catch Module:stop(Host) of
{'EXIT', Reason} -> ?ERROR_MSG("~p", [Reason]), error;
{wait, ProcList} when is_list(ProcList) ->
lists:foreach(fun wait_for_process/1, ProcList),
ets:delete(ejabberd_modules, {Module, Host}),
ok;
{wait, Process} ->
wait_for_process(Process),
ets:delete(ejabberd_modules, {Module, Host}),
ok;
_ -> ets:delete(ejabberd_modules, {Module, Host}), ok
end.
wait_for_process(Process) ->
MonitorReference = erlang:monitor(process, Process),
wait_for_stop(Process, MonitorReference).
wait_for_stop(Process, MonitorReference) ->
receive
{'DOWN', MonitorReference, _Type, _Object, _Info} -> ok
after 5000 ->
catch exit(whereis(Process), kill),
wait_for_stop1(MonitorReference)
end.
wait_for_stop1(MonitorReference) ->
receive
{'DOWN', MonitorReference, _Type, _Object, _Info} -> ok
after 5000 -> ok
end.
-type check_fun() :: fun((any()) -> any()) | {module(), atom()}.
-spec get_opt(atom(), opts(), check_fun()) -> any().
get_opt(Opt, Opts, F) ->
get_opt(Opt, Opts, F, undefined).
-spec get_opt(atom(), opts(), check_fun(), any()) -> any().
get_opt(Opt, Opts, F, Default) ->
case lists:keysearch(Opt, 1, Opts) of
false ->
Default;
{value, {_, Val}} ->
ejabberd_config:prepare_opt_val(Opt, Val, F, Default)
end.
-spec get_module_opt(global | binary(), atom(), atom(), check_fun(), any()) -> any().
get_module_opt(global, Module, Opt, F, Default) ->
Hosts = (?MYHOSTS),
[Value | Values] = lists:map(fun (Host) ->
get_module_opt(Host, Module, Opt,
F, Default)
end,
Hosts),
Same_all = lists:all(fun (Other_value) ->
Other_value == Value
end,
Values),
case Same_all of
true -> Value;
false -> Default
end;
get_module_opt(Host, Module, Opt, F, Default) ->
OptsList = ets:lookup(ejabberd_modules, {Module, Host}),
case OptsList of
[] -> Default;
[#ejabberd_module{opts = Opts} | _] ->
get_opt(Opt, Opts, F, Default)
end.
-spec get_module_opt_host(global | binary(), atom(), binary()) -> binary().
get_module_opt_host(Host, Module, Default) ->
Val = get_module_opt(Host, Module, host,
fun iolist_to_binary/1,
Default),
ejabberd_regexp:greplace(Val, <<"@HOST@">>, Host).
-spec get_opt_host(binary(), opts(), binary()) -> binary().
get_opt_host(Host, Opts, Default) ->
Val = get_opt(host, Opts, fun iolist_to_binary/1, Default),
ejabberd_regexp:greplace(Val, <<"@HOST@">>, Host).
-spec db_type(opts()) -> odbc | mnesia.
db_type(Opts) ->
get_opt(db_type, Opts,
fun(odbc) -> odbc;
(internal) -> mnesia;
(mnesia) -> mnesia end,
mnesia).
-spec db_type(binary(), atom()) -> odbc | mnesia.
db_type(Host, Module) ->
get_module_opt(Host, Module, db_type,
fun(odbc) -> odbc;
(internal) -> mnesia;
(mnesia) -> mnesia end,
mnesia).
-spec loaded_modules(binary()) -> [atom()].
loaded_modules(Host) ->
ets:select(ejabberd_modules,
[{#ejabberd_module{_ = '_', module_host = {'$1', Host}},
[], ['$1']}]).
-spec loaded_modules_with_opts(binary()) -> [{atom(), opts()}].
loaded_modules_with_opts(Host) ->
ets:select(ejabberd_modules,
[{#ejabberd_module{_ = '_', module_host = {'$1', Host},
opts = '$2'},
[], [{{'$1', '$2'}}]}]).
set_module_opts_mnesia(Host, Module, Opts) ->
Modules = ejabberd_config:get_local_option(
{modules, Host},
fun(Ls) when is_list(Ls) -> Ls end,
[]),
Modules1 = lists:keydelete(Module, 1, Modules),
Modules2 = [{Module, Opts} | Modules1],
ejabberd_config:add_local_option({modules, Host},
Modules2).
del_module_mnesia(Host, Module) ->
Modules = ejabberd_config:get_local_option(
{modules, Host},
fun(Ls) when is_list(Ls) -> Ls end,
[]),
Modules1 = lists:keydelete(Module, 1, Modules),
ejabberd_config:add_local_option({modules, Host},
Modules1).
-spec get_hosts(opts(), binary()) -> [binary()].
get_hosts(Opts, Prefix) ->
case get_opt(hosts, Opts,
fun(Hs) -> [iolist_to_binary(H) || H <- Hs] end) of
undefined ->
case get_opt(host, Opts,
fun iolist_to_binary/1) of
undefined ->
[<<Prefix/binary, Host/binary>> || Host <- ?MYHOSTS];
Host ->
[Host]
end;
Hosts ->
Hosts
end.
-spec get_module_proc(binary(), {frontend, atom()} | atom()) -> atom().
get_module_proc(Host, {frontend, Base}) ->
get_module_proc(<<"frontend_", Host/binary>>, Base);
get_module_proc(Host, Base) ->
binary_to_atom(
<<(erlang:atom_to_binary(Base, latin1))/binary, "_", Host/binary>>,
latin1).
-spec is_loaded(binary(), atom()) -> boolean().
is_loaded(Host, Module) ->
ets:member(ejabberd_modules, {Module, Host}).
