%%%----------------------------------------------------------------------
%%% 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 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').
-behavior(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]).
-include_lib("stdlib/include/ms_transform.hrl").
-include("logger.hrl").
-include("xmpp.hrl").
-record(push_session,
{us = {<<"">>, <<"">>} :: {binary(), binary()},
timestamp = p1_time_compat:timestamp() :: erlang:timestamp(),
service = {<<"">>, <<"">>, <<"">>} :: ljid(),
node = <<"">> :: binary(),
xdata = #xdata{} :: xdata()}).
%%%-------------------------------------------------------------------
%%% 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() ->
if is_integer(MaxSessions) ->
enforce_max_sessions(US, MaxSessions - 1);
MaxSessions == infinity ->
ok
end,
mnesia:write(#push_session{us = US,
timestamp = TS,
service = PushLJID,
node = Node,
xdata = XData})
end,
case mnesia:transaction(F) of
{atomic, ok} ->
{ok, {TS, PushLJID, Node, XData}};
{aborted, E} ->
?ERROR_MSG("Cannot store push session for ~s@~s: ~p",
[LUser, LServer, E]),
error
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, xdata = XData}] ->
{ok, {TS, PushLJID, Node, XData}};
_ ->
?DEBUG("No push session found for ~s@~s (~p, ~s)",
[LUser, LServer, PushJID, Node]),
error
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, xdata = XData}] ->
{ok, {TS, PushLJID, Node, XData}};
_ ->
?DEBUG("No push session found for ~s@~s (~p)",
[LUser, LServer, TS]),
error
end.
lookup_sessions(LUser, LServer, PushJID) ->
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 ->
Rec
end),
{ok, mnesia:dirty_select(push_session, MatchSpec)}.
lookup_sessions(LUser, LServer) ->
Records = mnesia:dirty_read(push_session, {LUser, LServer}),
Clients = [{TS, PushLJID, Node, XData}
|| #push_session{timestamp = TS,
service = PushLJID,
node = Node,
xdata = XData} <- Records],
{ok, Clients}.
lookup_sessions(LServer) ->
MatchSpec = ets:fun2ms(
fun(#push_session{us = {_U, S},
timestamp = TS,
service = PushLJID,
node = Node,
xdata = XData})
when S == LServer ->
{TS, PushLJID, Node, XData}
end),
{ok, mnesia:dirty_select(push_session, MatchSpec)}.
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 ~s@~s: ~p",
[LUser, LServer, E]),
error
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
end.
%%--------------------------------------------------------------------
%% Internal functions.
%%--------------------------------------------------------------------
-spec enforce_max_sessions({binary(), binary()}, non_neg_integer()) -> ok.
enforce_max_sessions({U, S} = US, Max) ->
Recs = mnesia:wread({push_session, US}),
NumRecs = length(Recs),
if NumRecs > Max ->
NumOldRecs = NumRecs - Max,
Recs1 = lists:keysort(#push_session.timestamp, Recs),
Recs2 = lists:reverse(Recs1),
OldRecs = lists:sublist(Recs2, Max + 1, NumOldRecs),
?INFO_MSG("Disabling ~B old push session(s) of ~s@~s",
[NumOldRecs, U, S]),
lists:foreach(fun(Rec) -> mnesia:delete_object(Rec) end, OldRecs);
true ->
ok
end.
