%%%----------------------------------------------------------------------
%%% File : gen_mod.erl
%%% Author : Alexey Shchepin <alexey@process-one.net>
%%% Purpose :
%%% Created : 24 Jan 2003 by Alexey Shchepin <alexey@process-one.net>
%%%
%%%
%%% ejabberd, Copyright (C) 2002-2009 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/2,
get_opt/3,
get_opt_host/3,
get_module_opt/4,
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").
-record(ejabberd_module, {module_host, opts}).
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.
start_module(Host, Module, Opts) ->
set_module_opts_mnesia(Host, Module, Opts),
ets:insert(ejabberd_modules,
#ejabberd_module{module_host = {Module, Host},
opts = Opts}),
case catch Module:start(Host, Opts) of
{'EXIT', Reason} ->
del_module_mnesia(Host, Module),
ets:delete(ejabberd_modules, {Module, Host}),
?ERROR_MSG("~p", [Reason]);
_ ->
ok
end.
%% @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.
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.
get_opt(Opt, Opts) ->
case lists:keysearch(Opt, 1, Opts) of
false ->
% TODO: replace with more appropriate function
throw({undefined_option, Opt});
{value, {_, Val}} ->
Val
end.
get_opt(Opt, Opts, Default) ->
case lists:keysearch(Opt, 1, Opts) of
false ->
Default;
{value, {_, Val}} ->
Val
end.
get_module_opt(global, Module, Opt, Default) ->
Hosts = ?MYHOSTS,
[Value | Values] = lists:map(
fun(Host) ->
get_module_opt(Host, Module, Opt, 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, Default) ->
OptsList = ets:lookup(ejabberd_modules, {Module, Host}),
case OptsList of
[] ->
Default;
[#ejabberd_module{opts = Opts} | _] ->
get_opt(Opt, Opts, Default)
end.
get_module_opt_host(Host, Module, Default) ->
Val = get_module_opt(Host, Module, host, Default),
element(2, regexp:gsub(Val, "@HOST@", Host)).
get_opt_host(Host, Opts, Default) ->
Val = get_opt(host, Opts, Default),
element(2, regexp:gsub(Val, "@HOST@", Host)).
loaded_modules(Host) ->
ets:select(ejabberd_modules,
[{#ejabberd_module{_ = '_', module_host = {'$1', Host}},
[],
['$1']}]).
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 = case ejabberd_config:get_local_option({modules, Host}) of
undefined ->
[];
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 = case ejabberd_config:get_local_option({modules, Host}) of
undefined ->
[];
Ls ->
Ls
end,
Modules1 = lists:keydelete(Module, 1, Modules),
ejabberd_config:add_local_option({modules, Host}, Modules1).
get_hosts(Opts, Prefix) ->
case catch gen_mod:get_opt(hosts, Opts) of
{'EXIT', _Error1} ->
case catch gen_mod:get_opt(host, Opts) of
{'EXIT', _Error2} ->
[Prefix ++ Host || Host <- ?MYHOSTS];
Host ->
[Host]
end;
Hosts ->
Hosts
end.
get_module_proc(Host, {frontend, Base}) ->
get_module_proc("frontend_" ++ Host, Base);
get_module_proc(Host, Base) ->
list_to_atom(atom_to_list(Base) ++ "_" ++ Host).
is_loaded(Host, Module) ->
ets:member(ejabberd_modules, {Module, Host}).
