%%%----------------------------------------------------------------------
%%% File : mod_push_mnesia.erl
%%% Author : Holger Weiss <holger@zedat.fu-berlin.de>
%%% Purpose : Mnesia backend for Push Notifications (XEP-0357)
%%% Created : 15 Jul 2017 by Holger Weiss <holger@zedat.fu-berlin.de>
%%%
%%%
%%% ejabberd, Copyright (C) 2017-2022 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(mod_push_mnesia).
-author('holger@zedat.fu-berlin.de').
-behaviour(mod_push).
%% API
-export([init/2, store_session/6, lookup_session/4, lookup_session/3,
lookup_sessions/3, lookup_sessions/2, lookup_sessions/1,
delete_session/3, delete_old_sessions/2, transform/1]).
-include_lib("stdlib/include/ms_transform.hrl").
-include("logger.hrl").
-include_lib("xmpp/include/xmpp.hrl").
-include("mod_push.hrl").
%%%-------------------------------------------------------------------
%%% API
%%%-------------------------------------------------------------------
init(_Host, _Opts) ->
ejabberd_mnesia:create(?MODULE, push_session,
[{disc_only_copies, [node()]},
{type, bag},
{attributes, record_info(fields, push_session)}]).
store_session(LUser, LServer, TS, PushJID, Node, XData) ->
US = {LUser, LServer},
PushLJID = jid:tolower(PushJID),
MaxSessions = ejabberd_sm:get_max_user_sessions(LUser, LServer),
F = fun() ->
enforce_max_sessions(US, MaxSessions),
mnesia:write(#push_session{us = US,
timestamp = TS,
service = PushLJID,
node = Node,
xml = encode_xdata(XData)})
end,
case mnesia:transaction(F) of
{atomic, ok} ->
{ok, {TS, PushLJID, Node, XData}};
{aborted, E} ->
?ERROR_MSG("Cannot store push session for ~ts@~ts: ~p",
[LUser, LServer, E]),
{error, db_failure}
end.
lookup_session(LUser, LServer, PushJID, Node) ->
PushLJID = jid:tolower(PushJID),
MatchSpec = ets:fun2ms(
fun(#push_session{us = {U, S}, service = P, node = N} = Rec)
when U == LUser,
S == LServer,
P == PushLJID,
N == Node ->
Rec
end),
case mnesia:dirty_select(push_session, MatchSpec) of
[#push_session{timestamp = TS, xml = El}] ->
{ok, {TS, PushLJID, Node, decode_xdata(El)}};
[] ->
?DEBUG("No push session found for ~ts@~ts (~p, ~ts)",
[LUser, LServer, PushJID, Node]),
{error, notfound}
end.
lookup_session(LUser, LServer, TS) ->
MatchSpec = ets:fun2ms(
fun(#push_session{us = {U, S}, timestamp = T} = Rec)
when U == LUser,
S == LServer,
T == TS ->
Rec
end),
case mnesia:dirty_select(push_session, MatchSpec) of
[#push_session{service = PushLJID, node = Node, xml = El}] ->
{ok, {TS, PushLJID, Node, decode_xdata(El)}};
[] ->
?DEBUG("No push session found for ~ts@~ts (~p)",
[LUser, LServer, TS]),
{error, notfound}
end.
lookup_sessions(LUser, LServer, PushJID) ->
PushLJID = jid:tolower(PushJID),
MatchSpec = ets:fun2ms(
fun(#push_session{us = {U, S}, service = P} = Rec)
when U == LUser,
S == LServer,
P == PushLJID ->
Rec
end),
Records = mnesia:dirty_select(push_session, MatchSpec),
{ok, records_to_sessions(Records)}.
lookup_sessions(LUser, LServer) ->
Records = mnesia:dirty_read(push_session, {LUser, LServer}),
{ok, records_to_sessions(Records)}.
lookup_sessions(LServer) ->
MatchSpec = ets:fun2ms(
fun(#push_session{us = {_U, S}} = Rec)
when S == LServer ->
Rec
end),
Records = mnesia:dirty_select(push_session, MatchSpec),
{ok, records_to_sessions(Records)}.
delete_session(LUser, LServer, TS) ->
MatchSpec = ets:fun2ms(
fun(#push_session{us = {U, S}, timestamp = T} = Rec)
when U == LUser,
S == LServer,
T == TS ->
Rec
end),
F = fun() ->
Recs = mnesia:select(push_session, MatchSpec),
lists:foreach(fun mnesia:delete_object/1, Recs)
end,
case mnesia:transaction(F) of
{atomic, ok} ->
ok;
{aborted, E} ->
?ERROR_MSG("Cannot delete push session of ~ts@~ts: ~p",
[LUser, LServer, E]),
{error, db_failure}
end.
delete_old_sessions(_LServer, Time) ->
DelIfOld = fun(#push_session{timestamp = T} = Rec, ok) when T < Time ->
mnesia:delete_object(Rec);
(_Rec, ok) ->
ok
end,
F = fun() ->
mnesia:foldl(DelIfOld, ok, push_session)
end,
case mnesia:transaction(F) of
{atomic, ok} ->
ok;
{aborted, E} ->
?ERROR_MSG("Cannot delete old push sessions: ~p", [E]),
{error, db_failure}
end.
transform({push_session, US, TS, Service, Node, XData}) ->
?INFO_MSG("Transforming push_session Mnesia table", []),
#push_session{us = US, timestamp = TS, service = Service,
node = Node, xml = encode_xdata(XData)}.
%%--------------------------------------------------------------------
%% Internal functions.
%%--------------------------------------------------------------------
-spec enforce_max_sessions({binary(), binary()}, non_neg_integer() | infinity)
-> ok.
enforce_max_sessions(_US, infinity) ->
ok;
enforce_max_sessions({U, S} = US, MaxSessions) ->
case mnesia:wread({push_session, US}) of
Recs when length(Recs) >= MaxSessions ->
Recs1 = lists:sort(fun(#push_session{timestamp = TS1},
#push_session{timestamp = TS2}) ->
TS1 >= TS2
end, Recs),
OldRecs = lists:nthtail(MaxSessions - 1, Recs1),
?INFO_MSG("Disabling old push session(s) of ~ts@~ts", [U, S]),
lists:foreach(fun(Rec) -> mnesia:delete_object(Rec) end, OldRecs);
_ ->
ok
end.
decode_xdata(undefined) ->
undefined;
decode_xdata(El) ->
xmpp:decode(El).
encode_xdata(undefined) ->
undefined;
encode_xdata(XData) ->
xmpp:encode(XData).
records_to_sessions(Records) ->
[{TS, PushLJID, Node, decode_xdata(El)}
|| #push_session{timestamp = TS,
service = PushLJID,
node = Node,
xml = El} <- Records].
