%%%-------------------------------------------------------------------
%%% Created : 11 Jan 2017 by Evgeny Khramtsov <ekhramtsov@process-one.net>
%%%
%%%
%%% ejabberd, Copyright (C) 2002-2022 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.,
%%% 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
%%%
%%%-------------------------------------------------------------------
-module(ejabberd_router_mnesia).
-behaviour(ejabberd_router).
-behaviour(gen_server).
%% API
-export([init/0, register_route/5, unregister_route/3, find_routes/1,
get_all_routes/0, use_cache/0]).
%% gen_server callbacks
-export([init/1, handle_cast/2, handle_call/3, handle_info/2,
terminate/2, code_change/3, start_link/0]).
-include("ejabberd_router.hrl").
-include("logger.hrl").
-include_lib("stdlib/include/ms_transform.hrl").
-record(state, {}).
%%%===================================================================
%%% API
%%%===================================================================
-spec init() -> ok | {error, any()}.
init() ->
Spec = {?MODULE, {?MODULE, start_link, []},
transient, 5000, worker, [?MODULE]},
case supervisor:start_child(ejabberd_backend_sup, Spec) of
{ok, _Pid} -> ok;
Err -> Err
end.
-spec start_link() -> {ok, pid()} | {error, any()}.
start_link() ->
gen_server:start_link({local, ?MODULE}, ?MODULE, [], []).
use_cache() ->
false.
register_route(Domain, ServerHost, LocalHint, undefined, Pid) ->
F = fun () ->
mnesia:write(#route{domain = Domain,
pid = Pid,
server_host = ServerHost,
local_hint = LocalHint})
end,
transaction(F);
register_route(Domain, ServerHost, _LocalHint, N, Pid) ->
F = fun () ->
case mnesia:wread({route, Domain}) of
[] ->
mnesia:write(#route{domain = Domain,
server_host = ServerHost,
pid = Pid,
local_hint = 1}),
lists:foreach(
fun (I) ->
mnesia:write(
#route{domain = Domain,
pid = undefined,
server_host = ServerHost,
local_hint = I})
end,
lists:seq(2, N));
Rs ->
lists:any(
fun (#route{pid = undefined,
local_hint = I} = R) ->
mnesia:write(
#route{domain = Domain,
pid = Pid,
server_host = ServerHost,
local_hint = I}),
mnesia:delete_object(R),
true;
(_) -> false
end,
Rs)
end
end,
transaction(F).
unregister_route(Domain, undefined, Pid) ->
F = fun () ->
case mnesia:select(
route,
ets:fun2ms(
fun(#route{domain = D, pid = P} = R)
when D == Domain, P == Pid -> R
end)) of
[R] -> mnesia:delete_object(R);
_ -> ok
end
end,
transaction(F);
unregister_route(Domain, _, Pid) ->
F = fun () ->
case mnesia:select(
route,
ets:fun2ms(
fun(#route{domain = D, pid = P} = R)
when D == Domain, P == Pid -> R
end)) of
[R] ->
I = R#route.local_hint,
ServerHost = R#route.server_host,
mnesia:write(#route{domain = Domain,
server_host = ServerHost,
pid = undefined,
local_hint = I}),
mnesia:delete_object(R);
_ -> ok
end
end,
transaction(F).
find_routes(Domain) ->
{ok, mnesia:dirty_read(route, Domain)}.
get_all_routes() ->
{ok, mnesia:dirty_select(
route,
ets:fun2ms(
fun(#route{domain = Domain, server_host = ServerHost})
when Domain /= ServerHost -> Domain
end))}.
%%%===================================================================
%%% gen_server callbacks
%%%===================================================================
init([]) ->
update_tables(),
ejabberd_mnesia:create(?MODULE, route,
[{ram_copies, [node()]},
{type, bag},
{attributes, record_info(fields, route)}]),
mnesia:subscribe({table, route, simple}),
lists:foreach(
fun (Pid) -> erlang:monitor(process, Pid) end,
mnesia:dirty_select(
route,
ets:fun2ms(
fun(#route{pid = Pid}) -> Pid end))),
{ok, #state{}}.
handle_call(Request, From, State) ->
?WARNING_MSG("Unexpected call from ~p: ~p", [From, Request]),
{noreply, State}.
handle_cast(Msg, State) ->
?WARNING_MSG("Unexpected cast: ~p", [Msg]),
{noreply, State}.
handle_info({mnesia_table_event,
{write, #route{pid = Pid}, _ActivityId}}, State) ->
erlang:monitor(process, Pid),
{noreply, State};
handle_info({mnesia_table_event, _}, State) ->
{noreply, State};
handle_info({'DOWN', _Ref, _Type, Pid, _Info}, State) ->
F = fun () ->
Es = mnesia:select(
route,
ets:fun2ms(
fun(#route{pid = P} = E)
when P == Pid -> E
end)),
lists:foreach(
fun(E) ->
if is_integer(E#route.local_hint) ->
LDomain = E#route.domain,
I = E#route.local_hint,
ServerHost = E#route.server_host,
mnesia:write(#route{domain = LDomain,
server_host = ServerHost,
pid = undefined,
local_hint = I}),
mnesia:delete_object(E);
true ->
mnesia:delete_object(E)
end
end, Es)
end,
transaction(F),
{noreply, State};
handle_info(Info, State) ->
?ERROR_MSG("Unexpected info: ~p", [Info]),
{noreply, State}.
terminate(_Reason, _State) ->
ok.
code_change(_OldVsn, State, _Extra) ->
{ok, State}.
%%%===================================================================
%%% Internal functions
%%%===================================================================
transaction(F) ->
case mnesia:transaction(F) of
{atomic, _} ->
ok;
{aborted, Reason} ->
?ERROR_MSG("Mnesia transaction failed: ~p", [Reason]),
{error, db_failure}
end.
-spec update_tables() -> ok.
update_tables() ->
try
mnesia:transform_table(route, ignore, record_info(fields, route))
catch exit:{aborted, {no_exists, _}} ->
ok
end,
case lists:member(local_route, mnesia:system_info(tables)) of
true -> mnesia:delete_table(local_route);
false -> ok
end.
