%%%-------------------------------------------------------------------
%%% Created : 12 Jan 2017 by Evgeny Khramtsov <ekhramtsov@process-one.net>
%%%
%%%
%%% ejabberd, Copyright (C) 2002-2018 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_bosh_mnesia).
-behaviour(gen_server).
-behaviour(mod_bosh).
%% mod_bosh API
-export([init/0, open_session/2, close_session/1, find_session/1,
use_cache/0]).
%% gen_server callbacks
-export([init/1, handle_call/3, handle_cast/2, handle_info/2,
terminate/2, code_change/3, start_link/0]).
-include("logger.hrl").
-record(bosh, {sid = <<"">> :: binary() | '_',
timestamp = p1_time_compat:timestamp() :: erlang:timestamp() | '_',
pid = self() :: pid() | '$1'}).
-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.
open_session(SID, Pid) ->
Session = #bosh{sid = SID, timestamp = p1_time_compat:timestamp(), pid = Pid},
lists:foreach(
fun(Node) when Node == node() ->
gen_server:call(?MODULE, {write, Session});
(Node) ->
cluster_send({?MODULE, Node}, {write, Session})
end, ejabberd_cluster:get_nodes()).
close_session(SID) ->
case mnesia:dirty_read(bosh, SID) of
[Session] ->
lists:foreach(
fun(Node) when Node == node() ->
gen_server:call(?MODULE, {delete, Session});
(Node) ->
cluster_send({?MODULE, Node}, {delete, Session})
end, ejabberd_cluster:get_nodes());
[] ->
ok
end.
find_session(SID) ->
case mnesia:dirty_read(bosh, SID) of
[#bosh{pid = Pid}] ->
{ok, Pid};
[] ->
{error, notfound}
end.
%%%===================================================================
%%% gen_server callbacks
%%%===================================================================
init([]) ->
setup_database(),
{ok, #state{}}.
handle_call({write, Session}, _From, State) ->
Res = write_session(Session),
{reply, Res, State};
handle_call({delete, Session}, _From, State) ->
Res = delete_session(Session),
{reply, Res, State};
handle_call(_Request, _From, State) ->
Reply = ok,
{reply, Reply, State}.
handle_cast(_Msg, State) ->
{noreply, State}.
handle_info({write, Session}, State) ->
write_session(Session),
{noreply, State};
handle_info({delete, Session}, State) ->
delete_session(Session),
{noreply, State};
handle_info(_Info, State) ->
?ERROR_MSG("got unexpected info: ~p", [_Info]),
{noreply, State}.
terminate(_Reason, _State) ->
ok.
code_change(_OldVsn, State, _Extra) ->
{ok, State}.
%%%===================================================================
%%% Internal functions
%%%===================================================================
write_session(#bosh{pid = Pid1, sid = SID, timestamp = T1} = S1) ->
case mnesia:dirty_read(bosh, SID) of
[#bosh{pid = Pid2, timestamp = T2} = S2] ->
if Pid1 == Pid2 ->
mnesia:dirty_write(S1);
T1 < T2 ->
cluster_send(Pid2, replaced),
mnesia:dirty_write(S1);
true ->
cluster_send(Pid1, replaced),
mnesia:dirty_write(S2)
end;
[] ->
mnesia:dirty_write(S1)
end.
delete_session(#bosh{sid = SID, pid = Pid1}) ->
case mnesia:dirty_read(bosh, SID) of
[#bosh{pid = Pid2}] ->
if Pid1 == Pid2 ->
mnesia:dirty_delete(bosh, SID);
true ->
ok
end;
[] ->
ok
end.
cluster_send(NodePid, Msg) ->
erlang:send(NodePid, Msg, [noconnect, nosuspend]).
setup_database() ->
case catch mnesia:table_info(bosh, attributes) of
[sid, pid] ->
mnesia:delete_table(bosh);
_ ->
ok
end,
ejabberd_mnesia:create(?MODULE, bosh,
[{ram_copies, [node()]}, {local_content, true},
{attributes, record_info(fields, bosh)}]).
