Add Redis as router RAM backend

src/ejabberd_router_redis.erl

@@ -0,0 +1,154 @@
+%%%-------------------------------------------------------------------
+%%% @author Evgeny Khramtsov <ekhramtsov@process-one.net>
+%%% Created : 28 Mar 2017 by Evgeny Khramtsov <ekhramtsov@process-one.net>
+%%%
+%%%
+%%% ejabberd, Copyright (C) 2002-2017   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(ejabberd_router_redis).
+-behaviour(ejabberd_router).
+
+%% API
+-export([init/0, register_route/5, unregister_route/3, find_routes/1,
+	 host_of_route/1, is_my_route/1, is_my_host/1, get_all_routes/0,
+	 find_routes/0]).
+
+-include("ejabberd.hrl").
+-include("logger.hrl").
+-include("ejabberd_router.hrl").
+
+-define(ROUTES_KEY, "ejabberd:routes").
+
+%%%===================================================================
+%%% API
+%%%===================================================================
+init() ->
+    clean_table().
+
+register_route(Domain, ServerHost, LocalHint, _, Pid) ->
+    DomKey = domain_key(Domain),
+    PidKey = term_to_binary(Pid),
+    T = term_to_binary({ServerHost, LocalHint}),
+    case ejabberd_redis:qp([["HSET", DomKey, PidKey, T],
+			    ["SADD", ?ROUTES_KEY, Domain]]) of
+	[{ok, _}, {ok, _}] ->
+	    ok;
+	Err ->
+	    ?ERROR_MSG("failed to register route in redis: ~p", [Err]),
+	    Err
+    end.
+
+unregister_route(Domain, _, Pid) ->
+    DomKey = domain_key(Domain),
+    PidKey = term_to_binary(Pid),
+    try
+	{ok, _} = ejabberd_redis:q(["HDEL", DomKey, PidKey]),
+	{ok, Num} = ejabberd_redis:q(["HLEN", DomKey]),
+	case binary_to_integer(Num) of
+	    0 ->
+		{ok, _} = ejabberd_redis:q(["SREM", ?ROUTES_KEY, Domain]),
+		ok;
+	    _ ->
+		ok
+	end
+    catch _:{badmatch, Err} ->
+	    ?ERROR_MSG("failed to unregister route in redis: ~p", [Err]),
+	    Err
+    end.
+
+find_routes(Domain) ->
+    DomKey = domain_key(Domain),
+    case ejabberd_redis:q(["HGETALL", DomKey]) of
+	{ok, Vals} ->
+	    decode_routes(Domain, Vals);
+	Err ->
+	    ?ERROR_MSG("failed to find routes in redis: ~p", [Err]),
+	    []
+    end.
+
+host_of_route(Domain) ->
+    DomKey = domain_key(Domain),
+    case ejabberd_redis:q(["HGETALL", DomKey]) of
+	{ok, [_, Data|_]} ->
+	    {ServerHost, _} = binary_to_term(Data),
+	    {ok, ServerHost};
+	{ok, []} ->
+	    error;
+	Err ->
+	    ?ERROR_MSG("failed to get host of route in redis: ~p", [Err]),
+	    error
+    end.
+
+is_my_route(Domain) ->
+    case ejabberd_redis:q(["SISMEMBER", ?ROUTES_KEY, Domain]) of
+	{ok, <<"1">>} -> true;
+	{ok, _} -> false;
+	Err ->
+	    ?ERROR_MSG("failed to check route in redis: ~p", [Err]),
+	    false
+    end.
+
+is_my_host(Domain) ->
+    {ok, Domain} == host_of_route(Domain).
+
+get_all_routes() ->
+    case ejabberd_redis:q(["SMEMBERS", ?ROUTES_KEY]) of
+	{ok, Routes} ->
+	    Routes;
+	Err ->
+	    ?ERROR_MSG("failed to fetch routes from redis: ~p", [Err]),
+	    []
+    end.
+
+find_routes() ->
+    lists:flatmap(
+      fun(Domain) ->
+	      DomKey = domain_key(Domain),
+	      case ejabberd_redis:q(["HGETALL", DomKey]) of
+		  {ok, Vals} ->
+		      decode_routes(Domain, Vals);
+		  Err ->
+		      ?ERROR_MSG("failed to fetch routes from redis: ~p",
+				 [Err]),
+		      []
+	      end
+      end, get_all_routes()).
+
+%%%===================================================================
+%%% Internal functions
+%%%===================================================================
+clean_table() ->
+    lists:foreach(
+      fun(#route{domain = Domain, pid = Pid}) when node(Pid) == node() ->
+	      unregister_route(Domain, undefined, Pid);
+	 (_) ->
+	      ok
+      end, find_routes()).
+
+domain_key(Domain) ->
+    <<"ejabberd:route:", Domain/binary>>.
+
+decode_routes(Domain, [Pid, Data|Vals]) ->
+    {ServerHost, LocalHint} = binary_to_term(Data),
+    [#route{domain = Domain,
+	    pid = binary_to_term(Pid),
+	    server_host = ServerHost,
+	    local_hint = LocalHint}|
+     decode_routes(Domain, Vals)];
+decode_routes(_, []) ->
+    [].