%%%----------------------------------------------------------------------
%%% File : gen_iq_handler.erl
%%% Author : Alexey Shchepin <alexey@process-one.net>
%%% Purpose : IQ handler support
%%% Created : 22 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_iq_handler).
-author('alexey@process-one.net').
-behaviour(gen_server).
%% API
-export([start_link/3, add_iq_handler/6,
remove_iq_handler/3, stop_iq_handler/3, handle/7,
process_iq/6, check_type/1, transform_module_options/1]).
%% gen_server callbacks
-export([init/1, handle_call/3, handle_cast/2,
handle_info/2, terminate/2, code_change/3]).
-include("ejabberd.hrl").
-include("logger.hrl").
-include("jlib.hrl").
-record(state, {host, module, function}).
-type component() :: ejabberd_sm | ejabberd_local.
-type type() :: no_queue | one_queue | pos_integer() | parallel.
-type opts() :: no_queue | {one_queue, pid()} | {queues, [pid()]} | parallel.
%%====================================================================
%% API
%%====================================================================
%%--------------------------------------------------------------------
%% Function: start_link() -> {ok,Pid} | ignore | {error,Error}
%% Description: Starts the server
%%--------------------------------------------------------------------
start_link(Host, Module, Function) ->
gen_server:start_link(?MODULE, [Host, Module, Function],
[]).
add_iq_handler(Component, Host, NS, Module, Function,
Type) ->
case Type of
no_queue ->
Component:register_iq_handler(Host, NS, Module,
Function, no_queue);
one_queue ->
{ok, Pid} = supervisor:start_child(ejabberd_iq_sup,
[Host, Module, Function]),
Component:register_iq_handler(Host, NS, Module,
Function, {one_queue, Pid});
N when is_integer(N) ->
Pids = lists:map(fun (_) ->
{ok, Pid} =
supervisor:start_child(ejabberd_iq_sup,
[Host, Module,
Function]),
Pid
end,
lists:seq(1, N)),
Component:register_iq_handler(Host, NS, Module,
Function, {queues, Pids});
parallel ->
Component:register_iq_handler(Host, NS, Module,
Function, parallel)
end.
remove_iq_handler(Component, Host, NS) ->
Component:unregister_iq_handler(Host, NS).
stop_iq_handler(_Module, _Function, Opts) ->
case Opts of
{one_queue, Pid} -> gen_server:call(Pid, stop);
{queues, Pids} ->
lists:foreach(fun (Pid) ->
catch gen_server:call(Pid, stop)
end,
Pids);
_ -> ok
end.
handle(Host, Module, Function, Opts, From, To, IQ) ->
case Opts of
no_queue ->
process_iq(Host, Module, Function, From, To, IQ);
{one_queue, Pid} -> Pid ! {process_iq, From, To, IQ};
{queues, Pids} ->
Pid = lists:nth(erlang:phash(now(), length(Pids)),
Pids),
Pid ! {process_iq, From, To, IQ};
parallel ->
spawn(?MODULE, process_iq,
[Host, Module, Function, From, To, IQ]);
_ -> todo
end.
process_iq(_Host, Module, Function, From, To, IQ) ->
case catch Module:Function(From, To, IQ) of
{'EXIT', Reason} -> ?ERROR_MSG("~p", [Reason]);
ResIQ ->
if ResIQ /= ignore ->
ejabberd_router:route(To, From, jlib:iq_to_xml(ResIQ));
true -> ok
end
end.
-spec check_type(type()) -> type().
check_type(no_queue) -> no_queue;
check_type(one_queue) -> one_queue;
check_type(N) when is_integer(N), N>0 -> N;
check_type(parallel) -> parallel.
-spec transform_module_options([{atom(), any()}]) -> [{atom(), any()}].
transform_module_options(Opts) ->
lists:map(
fun({iqdisc, {queues, N}}) ->
{iqdisc, N};
(Opt) ->
Opt
end, Opts).
%%====================================================================
%% gen_server callbacks
%%====================================================================
%%--------------------------------------------------------------------
%% Function: init(Args) -> {ok, State} |
%% {ok, State, Timeout} |
%% ignore |
%% {stop, Reason}
%% Description: Initiates the server
%%--------------------------------------------------------------------
init([Host, Module, Function]) ->
{ok,
#state{host = Host, module = Module,
function = Function}}.
%%--------------------------------------------------------------------
%% Function: %% handle_call(Request, From, State) -> {reply, Reply, State} |
%% {reply, Reply, State, Timeout} |
%% {noreply, State} |
%% {noreply, State, Timeout} |
%% {stop, Reason, Reply, State} |
%% {stop, Reason, State}
%% Description: Handling call messages
%%--------------------------------------------------------------------
handle_call(stop, _From, State) ->
Reply = ok, {stop, normal, Reply, State}.
%%--------------------------------------------------------------------
%% Function: handle_cast(Msg, State) -> {noreply, State} |
%% {noreply, State, Timeout} |
%% {stop, Reason, State}
%% Description: Handling cast messages
%%--------------------------------------------------------------------
handle_cast(_Msg, State) -> {noreply, State}.
%%--------------------------------------------------------------------
%% Function: handle_info(Info, State) -> {noreply, State} |
%% {noreply, State, Timeout} |
%% {stop, Reason, State}
%% Description: Handling all non call/cast messages
%%--------------------------------------------------------------------
handle_info({process_iq, From, To, IQ},
#state{host = Host, module = Module,
function = Function} =
State) ->
process_iq(Host, Module, Function, From, To, IQ),
{noreply, State};
handle_info(_Info, State) -> {noreply, State}.
%%--------------------------------------------------------------------
%% Function: terminate(Reason, State) -> void()
%% Description: This function is called by a gen_server when it is about to
%% terminate. It should be the opposite of Module:init/1 and do any necessary
%% cleaning up. When it returns, the gen_server terminates with Reason.
%% The return value is ignored.
%%--------------------------------------------------------------------
terminate(_Reason, _State) -> ok.
%%--------------------------------------------------------------------
%% Func: code_change(OldVsn, State, Extra) -> {ok, NewState}
%% Description: Convert process state when code is changed
%%--------------------------------------------------------------------
code_change(_OldVsn, State, _Extra) -> {ok, State}.
%%--------------------------------------------------------------------
%%% Internal functions
%%--------------------------------------------------------------------
