Make count_offline_messages cache work when offline uses mam for storage

This also replace existing cache for checking if spool is empty with this
cache.

src/mod_offline.erl

@@ -98,7 +98,7 @@
 -callback remove_old_messages(non_neg_integer(), binary()) -> {atomic, any()}.
 -callback remove_user(binary(), binary()) -> any().
 -callback read_message_headers(binary(), binary()) ->
-    [{non_neg_integer(), jid(), jid(), undefined | erlang:timestamp(), xmlel()}].
+    [{non_neg_integer(), jid(), jid(), undefined | erlang:timestamp(), xmlel()}] | error.
 -callback read_message(binary(), binary(), non_neg_integer()) ->
     {ok, #offline_msg{}} | error.
 -callback remove_message(binary(), binary(), non_neg_integer()) -> ok | {error, any()}.
@@ -222,26 +222,26 @@ store_offline_msg(#offline_msg{us = {User, Server}, packet = Pkt} = Msg) ->
     Mod = gen_mod:db_mod(Server, ?MODULE),
     case UseMam andalso xmpp:get_meta(Pkt, mam_archived, false) of
 	true ->
-	    ets_cache:lookup(?EMPTY_SPOOL_CACHE, {User, Server},
-		fun() ->
-		    case count_messages_in_db(Mod, User, Server) of
+	    case count_offline_messages(User, Server) of
 		0 ->
-			    case Mod:store_message(Msg) of
-				ok ->
-				    {cache, ok};
-				Err ->
-				    {nocache, Err}
-			    end;
+		    store_message_in_db(Mod, Msg);
 		_ ->
-			    {cache, ok}
+		    case use_cache(Mod, Server) of
+			true ->
+			    ets_cache:incr(
+				?SPOOL_COUNTER_CACHE,
+				{User, Server}, 1,
+				cache_nodes(Mod, Server));
+			false ->
+			    ok
 		    end
-		end);
+	    end;
 	false ->
 	    case get_max_user_messages(User, Server) of
 		infinity ->
 		    store_message_in_db(Mod, Msg);
 		Limit ->
-		    Num = count_messages_in_db(Mod, User, Server),
+		    Num = count_offline_messages(User, Server),
 		    if Num < Limit ->
 			    store_message_in_db(Mod, Msg);
 		       true ->
@@ -288,7 +288,12 @@ get_sm_items(_Acc, #jid{luser = U, lserver = S} = JID,
 	     ?NS_FLEX_OFFLINE, _Lang) ->
     ejabberd_sm:route(JID, {resend_offline, false}),
 	    Mod = gen_mod:db_mod(S, ?MODULE),
-	    Hdrs = Mod:read_message_headers(U, S),
+	    Hdrs = case Mod:read_message_headers(U, S) of
+		       L when is_list(L) ->
+			   L;
+		       _ ->
+			   []
+		   end,
 	    BareJID = jid:remove_resource(JID),
 	    {result, lists:map(
 		       fun({Seq, From, _To, _TS, _El}) ->
@@ -516,9 +521,31 @@ store_packet({_Action, #message{from = From, to = To} = Packet} = Acc) ->
 				    stop
 			    end
 		    end;
-		_ -> Acc
+		_ ->
+		    maybe_update_cache(To, Packet),
+		    Acc
 	    end;
-	false -> Acc
+	false ->
+	    maybe_update_cache(To, Packet),
+	    Acc
+    end.
+
+-spec maybe_update_cache(jid(), message()) -> ok.
+maybe_update_cache(#jid{lserver = Server, luser = User}, Packet) ->
+    case xmpp:get_meta(Packet, mam_archived, false) of
+	true ->
+	    Mod = gen_mod:db_mod(Server, ?MODULE),
+	    case use_mam_for_user(User, Server) andalso use_cache(Mod, Server) of
+		true ->
+		    ets_cache:incr(
+			?SPOOL_COUNTER_CACHE,
+			{User, Server}, 1,
+			cache_nodes(Mod, Server));
+		_ ->
+		    ok
+	    end;
+	_ ->
+	    ok
     end.
 
 -spec check_store_hint(message()) -> store | no_store | none.
@@ -750,7 +777,12 @@ offline_msg_to_route(LServer, #offline_msg{from = From, to = To} = R) ->
 
 -spec read_messages(binary(), binary()) -> [{binary(), message()}].
 read_messages(LUser, LServer) ->
-    Res = read_db_messages(LUser, LServer),
+    Res = case read_db_messages(LUser, LServer) of
+	      error ->
+		  [];
+	      L when is_list(L) ->
+		  L
+	  end,
     case use_mam_for_user(LUser, LServer) of
 	true ->
 	    read_mam_messages(LUser, LServer, Res);
@@ -758,10 +790,14 @@ read_messages(LUser, LServer) ->
 	    Res
     end.
 
--spec read_db_messages(binary(), binary()) -> [{binary(), message()}].
+-spec read_db_messages(binary(), binary()) -> [{binary(), message()}] | error.
 read_db_messages(LUser, LServer) ->
     Mod = gen_mod:db_mod(LServer, ?MODULE),
     CodecOpts = ejabberd_config:codec_options(),
+    case Mod:read_message_headers(LUser, LServer) of
+	error ->
+	    error;
+	L ->
 	    lists:flatmap(
 		fun({Seq, From, To, TS, El}) ->
 		    Node = integer_to_binary(Seq),
@@ -778,7 +814,8 @@ read_db_messages(LUser, LServer) ->
 				    xmpp:format_error(Why)]),
 			[]
 		    end
-	end, Mod:read_message_headers(LUser, LServer)).
+		end, L)
+    end.
 
 -spec parse_marker_messages(binary(), [#offline_msg{} | {any(), message()}]) ->
     {integer() | none, [message()]}.
@@ -896,13 +933,15 @@ read_mam_messages(LUser, LServer, ReadMsgs) ->
 	end, 1, AllMsgs2),
     AllMsgs3.
 
--spec count_mam_messages(binary(), binary(), [#offline_msg{} | {any(), message()}]) ->
-    integer().
+-spec count_mam_messages(binary(), binary(), [#offline_msg{} | {any(), message()}] | error) ->
+    {cache, integer()} | {nocache, integer()}.
+count_mam_messages(_LUser, _LServer, error) ->
+    {nocache, 0};
 count_mam_messages(LUser, LServer, ReadMsgs) ->
     {Start, ExtraMsgs} = parse_marker_messages(LServer, ReadMsgs),
     case Start of
 	none ->
-	    length(ExtraMsgs);
+	    {cache, length(ExtraMsgs)};
 	_ ->
 	    MaxOfflineMsgs = case get_max_user_messages(LUser, LServer) of
 				 Number when is_integer(Number) -> Number - length(ExtraMsgs);
@@ -914,7 +953,7 @@ count_mam_messages(LUser, LServer, ReadMsgs) ->
 					   #rsm_set{max = MaxOfflineMsgs,
 						    before = <<"9999999999999999">>},
 					   chat, only_count),
-	    Count + length(ExtraMsgs)
+	    {cache, Count + length(ExtraMsgs)}
     end.
 
 format_user_queue(Hdrs) ->
@@ -957,7 +996,10 @@ user_queue(User, Server, Query, Lang) ->
     US = {LUser, LServer},
     Mod = gen_mod:db_mod(LServer, ?MODULE),
     user_queue_parse_query(LUser, LServer, Query),
-    HdrsAll = Mod:read_message_headers(LUser, LServer),
+    HdrsAll = case Mod:read_message_headers(LUser, LServer) of
+		  error -> [];
+		  L -> L
+	      end,
     Hdrs = get_messages_subset(User, Server, HdrsAll),
     FMsgs = format_user_queue(Hdrs),
     [?XC(<<"h1">>,
@@ -1082,17 +1124,22 @@ webadmin_user_parse_query(Acc, _Action, _User, _Server,
 count_offline_messages(User, Server) ->
     LUser = jid:nodeprep(User),
     LServer = jid:nameprep(Server),
+    Mod = gen_mod:db_mod(LServer, ?MODULE),
     case use_mam_for_user(User, Server) of
 	true ->
+	    case use_cache(Mod, LServer) of
+		true ->
+		    ets_cache:lookup(
+			?SPOOL_COUNTER_CACHE, {LUser, LServer},
+			fun() ->
 			    Res = read_db_messages(LUser, LServer),
-	    count_mam_messages(LUser, LServer, Res);
+			    count_mam_messages(LUser, LServer, Res)
+			end);
+		false ->
+		    Res = read_db_messages(LUser, LServer),
+		    ets_cache:untag(count_mam_messages(LUser, LServer, Res))
+	    end;
 	_ ->
-	    Mod = gen_mod:db_mod(LServer, ?MODULE),
-	    count_messages_in_db(Mod, LUser, LServer)
-    end.
-
--spec count_messages_in_db(module(), binary(), binary()) -> non_neg_integer().
-count_messages_in_db(Mod, LUser, LServer) ->
 	    case use_cache(Mod, LServer) of
 		true ->
 		    ets_cache:lookup(
@@ -1102,6 +1149,7 @@ count_messages_in_db(Mod, LUser, LServer) ->
 			end);
 		false ->
 		    ets_cache:untag(Mod:count_messages(LUser, LServer))
+	    end
     end.
 
 -spec store_message_in_db(module(), #offline_msg{}) -> ok | {error, any()}.

src/mod_offline_riak.erl

@@ -88,7 +88,7 @@ read_message_headers(LUser, LServer) ->
 		     end, Rs),
 	    lists:keysort(1, Hdrs);
 	_Err ->
-	    []
+	    error
     end.
 
 read_message(_LUser, _LServer, I) ->

src/mod_offline_sql.erl

@@ -131,7 +131,7 @@ read_message_headers(LUser, LServer) ->
 		      end
 	      end, Rows);
 	_Err ->
-	    []
+	    error
     end.
 
 read_message(LUser, LServer, Seq) ->

test/ejabberd_SUITE_data/ejabberd.mysql.yml

@@ -22,6 +22,7 @@ define_macro:
         db_type: sql
         ram_db_type: sql
       mod_offline:
+        use_cache: true
         db_type: sql
       mod_privacy:
         db_type: sql

test/ejabberd_SUITE_data/ejabberd.pgsql.yml

@@ -22,6 +22,7 @@ define_macro:
         db_type: sql
         ram_db_type: sql
       mod_offline:
+        use_cache: true
         db_type: sql
       mod_privacy:
         db_type: sql