%%%----------------------------------------------------------------------
%%% File : ejabberd_router_multicast.erl
%%% Author : Badlop <badlop@process-one.net>
%%% Purpose : Multicast router
%%% Created : 11 Aug 2007 by Badlop <badlop@process-one.net>
%%%----------------------------------------------------------------------
-module(ejabberd_router_multicast).
-author('alexey@process-one.net').
-author('badlop@process-one.net').
-behaviour(gen_server).
%% API
-export([route_multicast/4,
register_route/1,
unregister_route/1
]).
-export([start_link/0]).
%% 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(route_multicast, {domain, pid}).
-record(state, {}).
%%====================================================================
%% API
%%====================================================================
%%--------------------------------------------------------------------
%% Function: start_link() -> {ok,Pid} | ignore | {error,Error}
%% Description: Starts the server
%%--------------------------------------------------------------------
start_link() ->
gen_server:start_link({local, ?MODULE}, ?MODULE, [], []).
route_multicast(From, Domain, Destinations, Packet) ->
case catch do_route(From, Domain, Destinations, Packet) of
{'EXIT', Reason} ->
?ERROR_MSG("~p~nwhen processing: ~p",
[Reason, {From, Domain, Destinations, Packet}]);
_ ->
ok
end.
register_route(Domain) ->
case jlib:nameprep(Domain) of
error ->
erlang:error({invalid_domain, Domain});
LDomain ->
Pid = self(),
F = fun() ->
mnesia:write(#route_multicast{domain = LDomain,
pid = Pid})
end,
mnesia:transaction(F)
end.
unregister_route(Domain) ->
case jlib:nameprep(Domain) of
error ->
erlang:error({invalid_domain, Domain});
LDomain ->
Pid = self(),
F = fun() ->
case mnesia:select(route_multicast,
[{#route_multicast{pid = Pid, domain = LDomain, _ = '_'},
[],
['$_']}]) of
[R] -> mnesia:delete_object(R);
_ -> ok
end
end,
mnesia:transaction(F)
end.
%%====================================================================
%% gen_server callbacks
%%====================================================================
%%--------------------------------------------------------------------
%% Function: init(Args) -> {ok, State} |
%% {ok, State, Timeout} |
%% ignore |
%% {stop, Reason}
%% Description: Initiates the server
%%--------------------------------------------------------------------
init([]) ->
mnesia:create_table(route_multicast,
[{ram_copies, [node()]},
{type, bag},
{attributes,
record_info(fields, route_multicast)}]),
mnesia:add_table_copy(route_multicast, node(), ram_copies),
mnesia:subscribe({table, route_multicast, simple}),
lists:foreach(
fun(Pid) ->
erlang:monitor(process, Pid)
end,
mnesia:dirty_select(route_multicast, [{{route_multicast, '_', '$1'}, [], ['$1']}])),
{ok, #state{}}.
%%--------------------------------------------------------------------
%% Function: %% handle_call(Request, From, State) -> {reply, Reply, State} |
%% {reply, Reply, State, Timeout} |
%% {noreply, State} |
%% {noreply, State, Timeout} |
%% {stop, Reason, Reply, State} |
%% {stop, Reason, State}
%% Description: Handling call messages
%%--------------------------------------------------------------------
handle_call(_Request, _From, State) ->
Reply = ok,
{reply, Reply, State}.
%%--------------------------------------------------------------------
%% Function: handle_cast(Msg, State) -> {noreply, State} |
%% {noreply, State, Timeout} |
%% {stop, Reason, State}
%% Description: Handling cast messages
%%--------------------------------------------------------------------
handle_cast(_Msg, State) ->
{noreply, State}.
%%--------------------------------------------------------------------
%% Function: handle_info(Info, State) -> {noreply, State} |
%% {noreply, State, Timeout} |
%% {stop, Reason, State}
%% Description: Handling all non call/cast messages
%%--------------------------------------------------------------------
handle_info({route_multicast, From, Domain, Destinations, Packet}, State) ->
case catch do_route(From, Domain, Destinations, Packet) of
{'EXIT', Reason} ->
?ERROR_MSG("~p~nwhen processing: ~p",
[Reason, {From, Domain, Destinations, Packet}]);
_ ->
ok
end,
{noreply, State};
handle_info({mnesia_table_event, {write, #route_multicast{pid = Pid}, _ActivityId}},
State) ->
erlang:monitor(process, Pid),
{noreply, State};
handle_info({'DOWN', _Ref, _Type, Pid, _Info}, State) ->
F = fun() ->
Es = mnesia:select(
route_multicast,
[{#route_multicast{pid = Pid, _ = '_'},
[],
['$_']}]),
lists:foreach(
fun(E) ->
mnesia:delete_object(E)
end, Es)
end,
mnesia:transaction(F),
{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
%%--------------------------------------------------------------------
%% From = #jid
%% Destinations = [#jid]
do_route(From, Domain, Destinations, Packet) ->
?DEBUG("route_multicast~n\tfrom ~s~n\tdomain ~s~n\tdestinations ~p~n\tpacket ~p~n",
[jlib:jid_to_string(From),
Domain,
[jlib:jid_to_string(To) || To <- Destinations],
Packet]),
%% Try to find an appropriate multicast service
case mnesia:dirty_read(route_multicast, Domain) of
%% If no multicast service is available in this server, send manually
[] -> do_route_normal(From, Destinations, Packet);
%% If some is available, send the packet using multicast service
Rs when is_list(Rs) ->
Pid = pick_multicast_pid(Rs),
Pid ! {route_trusted, From, Destinations, Packet}
end.
pick_multicast_pid(Rs) ->
List = case [R || R <- Rs, node(R#route_multicast.pid) == node()] of
[] -> Rs;
RLocals -> RLocals
end,
(hd(List))#route_multicast.pid.
do_route_normal(From, Destinations, Packet) ->
[ejabberd_router:route(From, To, Packet) || To <- Destinations].
