Add Riak as mod_proxy65 RAM backend

src/mod_proxy65_riak.erl

@@ -0,0 +1,111 @@
+%%%-------------------------------------------------------------------
+%%% @author Evgeny Khramtsov <ekhramtsov@process-one.net>
+%%% Created : 15 Apr 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(mod_proxy65_riak).
+-behaviour(mod_proxy65).
+
+%% API
+-export([init/0, register_stream/2, unregister_stream/1, activate_stream/4]).
+
+-include("logger.hrl").
+
+-record(proxy65, {sid   :: binary(),
+		  pid_t :: pid(),
+		  pid_i :: pid() | undefined,
+		  jid_i :: binary() | undefined}).
+
+%%%===================================================================
+%%% API
+%%%===================================================================
+init() ->
+    clean_table().
+
+register_stream(SID, Pid) ->
+    case ejabberd_riak:get(proxy65, proxy65_schema(), SID) of
+	{error, notfound} ->
+	    ejabberd_riak:put(#proxy65{sid = SID, pid_t = Pid},
+			      proxy65_schema());
+	{ok, #proxy65{pid_i = undefined} = R} ->
+	    ejabberd_riak:put(R#proxy65{pid_i = Pid},
+			      proxy65_schema());
+	{ok, _} ->
+	    {error, conflict};
+	{error, _} ->
+	    {error, db_failure}
+    end.
+
+unregister_stream(SID) ->
+    case ejabberd_riak:delete(proxy65, SID) of
+	ok -> ok;
+	{error, _} -> {error, db_failure}
+    end.
+
+activate_stream(SID, IJID, MaxConnections, _Node) ->
+    try
+	case ejabberd_riak:get(proxy65, proxy65_schema(), SID) of
+	    {ok, #proxy65{pid_t = TPid, pid_i = IPid,
+			  jid_i = undefined} = R} when is_pid(IPid) ->
+		{ok, Num} = ejabberd_riak:count_by_index(
+			      proxy65, <<"jid_i">>, IJID),
+		if Num >= MaxConnections ->
+			{error, {limit, IPid, TPid}};
+		   true ->
+			ok = ejabberd_riak:put(
+			       R#proxy65{jid_i = IJID},
+			       proxy65_schema(),
+			       [{'2i', [{<<"jid_i">>, IJID}]}]),
+			{ok, IPid, TPid}
+		end;
+	    {ok, #proxy65{jid_i = JID}} ->
+		if is_binary(JID) -> {error, conflict};
+		   true -> {error, notfound}
+		end;
+	    {error, _} = Err ->
+		Err
+	end
+    catch _:{badmatch, {error, _}} ->
+	    {error, db_failure}
+    end.
+
+%%%===================================================================
+%%% Internal functions
+%%%===================================================================
+proxy65_schema() ->
+    {record_info(fields, proxy65), #proxy65{}}.
+
+clean_table() ->
+    ?INFO_MSG("Cleaning Riak 'proxy65' table...", []),
+    case ejabberd_riak:get(proxy65, proxy65_schema()) of
+	{ok, Rs} ->
+	    lists:foreach(
+	      fun(#proxy65{sid = SID, pid_t = TPid, pid_i = IPid}) ->
+		      if node(TPid) == node() orelse
+			 (is_pid(IPid) andalso node(IPid) == node()) ->
+			      ejabberd_riak:delete(proxy65, SID);
+			 true ->
+			      ok
+		      end
+	      end, Rs);
+	{error, Reason} = Err ->
+	    ?ERROR_MSG("Failed to clean Riak 'proxy65' table: ~p", [Reason]),
+	    Err
+    end.