Implement cache for mod_announce

src/mod_announce.erl

@@ -36,7 +36,7 @@
 	 import_start/2, import/5, announce/1, send_motd/1, disco_identity/5,
 	 disco_features/5, disco_items/5, depends/2,
 	 send_announcement_to_all/3, announce_commands/4,
-	 announce_items/4, mod_opt_type/1]).
+	 announce_items/4, mod_opt_type/1, clean_cache/1]).
 -export([init/1, handle_call/3, handle_cast/2,
 	 handle_info/2, terminate/2, code_change/3]).
 -export([announce_all/1,
@@ -57,17 +57,22 @@
 
 -callback init(binary(), gen_mod:opts()) -> any().
 -callback import(binary(), binary(), [binary()]) -> ok.
--callback set_motd_users(binary(), [{binary(), binary(), binary()}]) -> {atomic, any()}.
+-callback set_motd_users(binary(), [{binary(), binary(), binary()}]) -> ok | {error, any()}.
--callback set_motd(binary(), xmlel()) -> {atomic, any()}.
+-callback set_motd(binary(), xmlel()) -> ok | {error, any()}.
--callback delete_motd(binary()) -> {atomic, any()}.
+-callback delete_motd(binary()) -> ok | {error, any()}.
--callback get_motd(binary()) -> {ok, xmlel()} | error.
+-callback get_motd(binary()) -> {ok, xmlel()} | error | {error, any()}.
--callback is_motd_user(binary(), binary()) -> boolean().
+-callback is_motd_user(binary(), binary()) -> {ok, boolean()} | {error, any()}.
--callback set_motd_user(binary(), binary()) -> {atomic, any()}.
+-callback set_motd_user(binary(), binary()) -> ok | {error, any()}.
+-callback use_cache(binary()) -> boolean().
+-callback cache_nodes(binary()) -> [node()].
+
+-optional_callbacks([use_cache/1, cache_nodes/1]).
 
 -record(state, {host :: binary()}).
 
 -define(NS_ADMINL(Sub), [<<"http:">>, <<"jabber.org">>, <<"protocol">>,
                          <<"admin">>, <<Sub>>]).
+-define(MOTD_CACHE, motd_cache).
 
 tokenize(Node) -> str:tokens(Node, <<"/#">>).
 
@@ -88,7 +93,7 @@ reload(Host, NewOpts, OldOpts) ->
        true ->
 	    ok
     end,
-    ok.
+    init_cache(NewMod, Host, NewOpts).
 
 depends(_Host, _Opts) ->
     [{mod_adhoc, hard}].
@@ -100,6 +105,7 @@ init([Host, Opts]) ->
     process_flag(trap_exit, true),
     Mod = gen_mod:db_mod(Host, Opts, ?MODULE),
     Mod:init(Host, Opts),
+    init_cache(Mod, Host, Opts),
     ejabberd_hooks:add(local_send_to_resource_hook, Host,
 		       ?MODULE, announce, 50),
     ejabberd_hooks:add(disco_local_identity, Host, ?MODULE, disco_identity, 50),
@@ -684,19 +690,19 @@ announce_all_hosts_motd_update(Packet) ->
 
 announce_motd_update(LServer, Packet) ->
     Mod = gen_mod:db_mod(LServer, ?MODULE),
-    Mod:delete_motd(LServer),
+    delete_motd(Mod, LServer),
-    Mod:set_motd(LServer, xmpp:encode(Packet)).
+    set_motd(Mod, LServer, xmpp:encode(Packet)).
 
 announce_motd_delete(#message{to = To}) ->
     LServer = To#jid.lserver,
     Mod = gen_mod:db_mod(LServer, ?MODULE),
-    Mod:delete_motd(LServer).
+    delete_motd(Mod, LServer).
 
 announce_all_hosts_motd_delete(_Packet) ->
     lists:foreach(
       fun(Host) ->
 	      Mod = gen_mod:db_mod(Host, ?MODULE),
-	      Mod:delete_motd(Host)
+	      delete_motd(Mod, Host)
       end, ?MYHOSTS).
 
 -spec send_motd({presence(), ejabberd_c2s:state()}) -> {presence(), ejabberd_c2s:state()}.
@@ -707,16 +713,16 @@ send_motd({#presence{type = available},
 	   #{jid := #jid{luser = LUser, lserver = LServer} = JID}} = Acc)
   when LUser /= <<>> ->
     Mod = gen_mod:db_mod(LServer, ?MODULE),
-    case Mod:get_motd(LServer) of
+    case get_motd(Mod, LServer) of
 	{ok, Packet} ->
 	    try xmpp:decode(Packet, ?NS_CLIENT, [ignore_els]) of
 		Msg ->
-		    case Mod:is_motd_user(LUser, LServer) of
+		    case is_motd_user(Mod, LUser, LServer) of
 			false ->
 			    Local = jid:make(LServer),
 			    ejabberd_router:route(
 			      xmpp:set_from_to(Msg, Local, JID)),
-			    Mod:set_motd_user(LUser, LServer);
+			    set_motd_user(Mod, LUser, LServer);
 			true ->
 			    ok
 		    end
@@ -724,16 +730,81 @@ send_motd({#presence{type = available},
 		    ?ERROR_MSG("failed to decode motd packet ~p: ~s",
 			       [Packet, xmpp:format_error(Why)])
 	    end;
-	error ->
+	_ ->
 	    ok
     end,
     Acc;
 send_motd(Acc) ->
     Acc.
 
+-spec get_motd(module(), binary()) -> {ok, xmlel()} | error | {error, any()}.
+get_motd(Mod, LServer) ->
+    case use_cache(Mod, LServer) of
+	true ->
+	    ets_cache:lookup(
+	      ?MOTD_CACHE, {<<"">>, LServer},
+	      fun() -> Mod:get_motd(LServer) end);
+	false ->
+	    Mod:get_motd(LServer)
+    end.
+
+-spec set_motd(module(), binary(), xmlel()) -> any().
+set_motd(Mod, LServer, XML) ->
+    case use_cache(Mod, LServer) of
+	true ->
+	    ets_cache:update(
+	      ?MOTD_CACHE, {<<"">>, LServer}, {ok, XML},
+	      fun() -> Mod:set_motd(LServer, XML) end,
+	      cache_nodes(Mod, LServer));
+	false ->
+	    Mod:set_motd(LServer, XML)
+    end.
+
+-spec is_motd_user(module(), binary(), binary()) -> boolean().
+is_motd_user(Mod, LUser, LServer) ->
+    Res = case use_cache(Mod, LServer) of
+	      true ->
+		  ets_cache:lookup(
+		    ?MOTD_CACHE, {LUser, LServer},
+		    fun() -> Mod:is_motd_user(LUser, LServer) end);
+	      false ->
+		  Mod:is_motd_user(LUser, LServer)
+	  end,
+    case Res of
+	{ok, Bool} -> Bool;
+	_ -> false
+    end.
+
+-spec set_motd_user(module(), binary(), binary()) -> any().
+set_motd_user(Mod, LUser, LServer) ->
+    case use_cache(Mod, LServer) of
+	true ->
+	    ets_cache:update(
+	      ?MOTD_CACHE, {LUser, LServer}, {ok, true},
+	      fun() -> Mod:set_motd_user(LUser, LServer) end,
+	      cache_nodes(Mod, LServer));
+	false ->
+	    Mod:set_motd_user(LUser, LServer)
+    end.
+
+-spec delete_motd(module(), binary()) -> ok | {error, any()}.
+delete_motd(Mod, LServer) ->
+    case Mod:delete_motd(LServer) of
+	ok ->
+	    case use_cache(Mod, LServer) of
+		true ->
+		    ejabberd_cluster:eval_everywhere(
+		      ?MODULE, clean_cache, [LServer]);
+		false ->
+		    ok
+	    end;
+	Err ->
+	    Err
+    end.
+
 get_stored_motd(LServer) ->
     Mod = gen_mod:db_mod(LServer, ?MODULE),
-    case Mod:get_motd(LServer) of
+    case get_motd(Mod, LServer) of
         {ok, Packet} ->
 	    try xmpp:decode(Packet, ?NS_CLIENT, [ignore_els]) of
 		#message{body = Body, subject = Subject} ->
@@ -742,7 +813,7 @@ get_stored_motd(LServer) ->
 		    ?ERROR_MSG("failed to decode motd packet ~p: ~s",
 			       [Packet, xmpp:format_error(Why)])
 	    end;
-        error ->
+        _ ->
             {<<>>, <<>>}
     end.
 
@@ -775,6 +846,55 @@ route_forbidden_error(Packet) ->
     Err = xmpp:err_forbidden(<<"Denied by ACL">>, Lang),
     ejabberd_router:route_error(Packet, Err).
 
+-spec init_cache(module(), binary(), gen_mod:opts()) -> ok.
+init_cache(Mod, Host, Opts) ->
+    case use_cache(Mod, Host) of
+	true ->
+	    CacheOpts = cache_opts(Host, Opts),
+	    ets_cache:new(?MOTD_CACHE, CacheOpts);
+	false ->
+	    ets_cache:delete(?MOTD_CACHE)
+    end.
+
+-spec cache_opts(binary(), gen_mod:opts()) -> [proplists:property()].
+cache_opts(Host, Opts) ->
+    MaxSize = gen_mod:get_opt(
+		cache_size, Opts,
+		ejabberd_config:cache_size(Host)),
+    CacheMissed = gen_mod:get_opt(
+		    cache_missed, Opts,
+		    ejabberd_config:cache_missed(Host)),
+    LifeTime = case gen_mod:get_opt(
+		      cache_life_time, Opts,
+		      ejabberd_config:cache_life_time(Host)) of
+		   infinity -> infinity;
+		   I -> timer:seconds(I)
+	       end,
+    [{max_size, MaxSize}, {cache_missed, CacheMissed}, {life_time, LifeTime}].
+
+-spec use_cache(module(), binary()) -> boolean().
+use_cache(Mod, Host) ->
+    case erlang:function_exported(Mod, use_cache, 1) of
+	true -> Mod:use_cache(Host);
+	false ->
+	    gen_mod:get_module_opt(
+	      Host, ?MODULE, use_cache,
+	      ejabberd_config:use_cache(Host))
+    end.
+
+-spec cache_nodes(module(), binary()) -> [node()].
+cache_nodes(Mod, Host) ->
+    case erlang:function_exported(Mod, cache_nodes, 1) of
+	true -> Mod:cache_nodes(Host);
+	false -> ejabberd_cluster:get_nodes()
+    end.
+
+-spec clean_cache(binary()) -> non_neg_integer().
+clean_cache(LServer) ->
+    ets_cache:filter(
+      ?MOTD_CACHE,
+      fun({_, S}, _) -> S /= LServer end).
+
 %%-------------------------------------------------------------------------
 export(LServer) ->
     Mod = gen_mod:db_mod(LServer, ?MODULE),

src/mod_announce_mnesia.erl

@@ -40,11 +40,11 @@
 %%%===================================================================
 init(_Host, _Opts) ->
     ejabberd_mnesia:create(?MODULE, motd,
-			[{disc_copies, [node()]},
+			[{disc_only_copies, [node()]},
 			 {attributes,
 			  record_info(fields, motd)}]),
     ejabberd_mnesia:create(?MODULE, motd_users,
-			[{disc_copies, [node()]},
+			[{disc_only_copies, [node()]},
 			 {attributes,
 			  record_info(fields, motd_users)}]).
 
@@ -55,13 +55,13 @@ set_motd_users(_LServer, USRs) ->
 			  mnesia:write(#motd_users{us = {U, S}})
 		  end, USRs)
 	end,
-    mnesia:transaction(F).
+    transaction(F).
 
 set_motd(LServer, Packet) ->
     F = fun() ->
 		mnesia:write(#motd{server = LServer, packet = Packet})
 	end,
-    mnesia:transaction(F).
+    transaction(F).
 
 delete_motd(LServer) ->
     F = fun() ->
@@ -76,27 +76,27 @@ delete_motd(LServer) ->
 				      mnesia:delete({motd_users, US})
 			      end, Users)
 	end,
-    mnesia:transaction(F).
+    transaction(F).
 
 get_motd(LServer) ->
     case mnesia:dirty_read({motd, LServer}) of
 	[#motd{packet = Packet}] ->
 	    {ok, Packet};
-	_ ->
+	[] ->
 	    error
     end.
 
 is_motd_user(LUser, LServer) ->
     case mnesia:dirty_read({motd_users, {LUser, LServer}}) of
-	[#motd_users{}] -> true;
+	[#motd_users{}] -> {ok, true};
-	_ -> false
+	_ -> {ok, false}
     end.
 
 set_motd_user(LUser, LServer) ->
     F = fun() ->
 		mnesia:write(#motd_users{us = {LUser, LServer}})
 	end,
-    mnesia:transaction(F).
+    transaction(F).
 
 need_transform(#motd{server = S}) when is_list(S) ->
     ?INFO_MSG("Mnesia table 'motd' will be converted to binary", []),
@@ -124,3 +124,11 @@ import(LServer, <<"motd">>, [LUser, <<>>, _TimeStamp]) ->
 %%%===================================================================
 %%% Internal functions
 %%%===================================================================
+transaction(F) ->
+    case mnesia:transaction(F) of
+	{atomic, Res} ->
+	    Res;
+	{aborted, Reason} ->
+	    ?ERROR_MSG("Mnesia transaction failed: ~p", [Reason]),
+	    {error, db_failure}
+    end.

src/mod_announce_riak.erl

@@ -46,47 +46,48 @@ set_motd_users(_LServer, USRs) ->
 		  ok = ejabberd_riak:put(#motd_users{us = {U, S}},
 					 motd_users_schema(),
 					 [{'2i', [{<<"server">>, S}]}])
-	  end, USRs),
+	  end, USRs)
-	{atomic, ok}
+    catch _:{badmatch, {error, _} = Err} ->
-    catch _:{badmatch, Err} ->
+	    Err
-	    {atomic, Err}
     end.
 
 set_motd(LServer, Packet) ->
-    {atomic, ejabberd_riak:put(#motd{server = LServer,
+    ejabberd_riak:put(#motd{server = LServer,
-				     packet = Packet},
+			    packet = Packet},
-			       motd_schema())}.
+		      motd_schema()).
 
 delete_motd(LServer) ->
     try
 	ok = ejabberd_riak:delete(motd, LServer),
 	ok = ejabberd_riak:delete_by_index(motd_users,
 					   <<"server">>,
-					   LServer),
+					   LServer)
-	{atomic, ok}
+    catch _:{badmatch, {error, _} = Err} ->
-    catch _:{badmatch, Err} ->
+	    Err
-	    {atomic, Err}
     end.
 
 get_motd(LServer) ->
     case ejabberd_riak:get(motd, motd_schema(), LServer) of
         {ok, #motd{packet = Packet}} ->
 	    {ok, Packet};
-	_ ->
+	{error, notfound} ->
-	    error
+	    error;
+	{error, _} = Err ->
+	    Err
     end.
 
 is_motd_user(LUser, LServer) ->
     case ejabberd_riak:get(motd_users, motd_users_schema(),
 			   {LUser, LServer}) of
-	{ok, #motd_users{}} -> true;
+	{ok, #motd_users{}} -> {ok, true};
-	_ -> false
+	{error, notfound} -> {ok, false};
+	{error, _} = Err -> Err
     end.
 
 set_motd_user(LUser, LServer) ->
-    {atomic, ejabberd_riak:put(
+    ejabberd_riak:put(
-	       #motd_users{us = {LUser, LServer}}, motd_users_schema(),
+      #motd_users{us = {LUser, LServer}}, motd_users_schema(),
-	       [{'2i', [{<<"server">>, LServer}]}])}.
+      [{'2i', [{<<"server">>, LServer}]}]).
 
 import(LServer, <<"motd">>, [<<>>, XML, _TimeStamp]) ->
     El = fxml_stream:parse_element(XML),

src/mod_announce_sql.erl

@@ -36,6 +36,7 @@
 -include("xmpp.hrl").
 -include("mod_announce.hrl").
 -include("ejabberd_sql_pt.hrl").
+-include("logger.hrl").
 
 %%%===================================================================
 %%% API
@@ -53,7 +54,7 @@ set_motd_users(LServer, USRs) ->
                               "xml=''"])
 		  end, USRs)
 	end,
-    ejabberd_sql:sql_transaction(LServer, F).
+    transaction(LServer, F).
 
 set_motd(LServer, Packet) ->
     XML = fxml:element_to_binary(Packet),
@@ -63,27 +64,24 @@ set_motd(LServer, Packet) ->
                    ["!username=''",
                     "xml=%(XML)s"])
 	end,
-    ejabberd_sql:sql_transaction(LServer, F).
+    transaction(LServer, F).
 
 delete_motd(LServer) ->
     F = fun() ->
                 ejabberd_sql:sql_query_t(?SQL("delete from motd"))
 	end,
-    ejabberd_sql:sql_transaction(LServer, F).
+    transaction(LServer, F).
 
 get_motd(LServer) ->
     case catch ejabberd_sql:sql_query(
                  LServer,
                  ?SQL("select @(xml)s from motd where username=''")) of
         {selected, [{XML}]} ->
-            case fxml_stream:parse_element(XML) of
+	    parse_element(XML);
-                {error, _} ->
+	{selected, []} ->
-                    error;
+	    error;
-                Packet ->
-		    {ok, Packet}
-	    end;
 	_ ->
-	    error
+	    {error, db_failure}
     end.
 
 is_motd_user(LUser, LServer) ->
@@ -92,9 +90,11 @@ is_motd_user(LUser, LServer) ->
                  ?SQL("select @(username)s from motd"
                       " where username=%(LUser)s")) of
         {selected, [_|_]} ->
-	    true;
+	    {ok, true};
+	{selected, []} ->
+	    {ok, false};
 	_ ->
-	    false
+	    {error, db_failure}
     end.
 
 set_motd_user(LUser, LServer) ->
@@ -104,7 +104,7 @@ set_motd_user(LUser, LServer) ->
                    ["!username=%(LUser)s",
                     "xml=''"])
         end,
-    ejabberd_sql:sql_transaction(LServer, F).
+    transaction(LServer, F).
 
 export(_Server) ->
     [{motd,
@@ -131,3 +131,18 @@ import(_, _, _) ->
 %%%===================================================================
 %%% Internal functions
 %%%===================================================================
+transaction(LServer, F) ->
+    case ejabberd_sql:sql_transaction(LServer, F) of
+	{atomic, _} -> ok;
+	_ -> {error, db_failure}
+    end.
+
+parse_element(XML) ->
+    case fxml_stream:parse_element(XML) of
+        El when is_record(El, xmlel) ->
+            {ok, El};
+        _ ->
+            ?ERROR_MSG("malformed XML element in SQL table "
+                       "'motd' for username='': ~s", [XML]),
+            {error, db_failure}
+    end.