refactor: do msg filter before deliver, and log level change to `debug`

apps/emqx_retainer/src/emqx_retainer_dispatcher.erl

@@ -308,12 +308,13 @@ deliver(Messages, Pid, Topic, Limiter) ->
             no_receiver;
         _ ->
             BatchSize = emqx_conf:get([retainer, flow_control, batch_deliver_number], undefined),
+            NMessages = filter_delivery(Messages, Topic),
             case BatchSize of
                 0 ->
-                    deliver_to_client(Messages, Pid, Topic),
+                    deliver_to_client(NMessages, Pid, Topic),
                     {ok, Limiter};
                 _ ->
-                    deliver_in_batches(Messages, BatchSize, Pid, Topic, Limiter)
+                    deliver_in_batches(NMessages, BatchSize, Pid, Topic, Limiter)
             end
     end.
 
@@ -334,28 +335,37 @@ deliver_in_batches(Msgs, BatchSize, Pid, Topic, Limiter0) ->
             Drop
     end.
 
+deliver_to_client([Msg | Rest], Pid, Topic) ->
+    Pid ! {deliver, Topic, Msg},
+    deliver_to_client(Rest, Pid, Topic);
+deliver_to_client([], _, _) ->
+    ok.
+
 -define(DELIVER_ALLOWED, true).
 -define(DELIVER_NOT_ALLOWED, false).
-
-deliver_to_client([Msg | T], Pid, Topic) ->
-    Pipe = emqx_utils:pipeline(
-        [
-            fun check_clientid_banned/2,
-            fun 'check_prefixed_$_with_wildcard'/2
-        ],
-        {Msg, Topic},
-        ?DELIVER_NOT_ALLOWED
-    ),
-    _ =
-        case Pipe of
-            {ok, _, ?DELIVER_ALLOWED} ->
-                Pid ! {deliver, Topic, Msg};
-            {error, _, _} ->
-                ok
+-define(msg_pub_from_is_banned, msg_pub_from_is_banned).
+-define(msg_topic_not_match, msg_topic_not_match).
+
+filter_delivery(Messages, Topic) ->
+    FilterFun =
+        fun(Msg) ->
+            Pipe = emqx_utils:pipeline(
+                [
+                    fun check_clientid_banned/2,
+                    fun 'check_prefixed_$_with_wildcard'/2
+                ],
+                {Msg, Topic},
+                ?DELIVER_NOT_ALLOWED
+            ),
+            _ =
+                case Pipe of
+                    {ok, _, ?DELIVER_ALLOWED} ->
+                        true;
+                    {error, _, _} ->
+                        false
+                end
         end,
-    deliver_to_client(T, Pid, Topic);
-deliver_to_client([], _, _) ->
-    ok.
+    lists:filter(FilterFun, Messages).
 
 check_clientid_banned({Msg, _Topic} = Input, _) ->
     case emqx_banned:check_clientid(Msg#message.from) of
@@ -363,29 +373,29 @@ check_clientid_banned({Msg, _Topic} = Input, _) ->
             {ok, Input, ?DELIVER_ALLOWED};
         true ->
             ?tp(
-                notice,
+                debug,
                 ignore_retained_message_deliver,
                 #{
-                    reason => client_is_banned,
+                    reason => ?msg_pub_from_is_banned,
                     clientid => Msg#message.from
                 }
             ),
-            {error, client_is_banned, ?DELIVER_NOT_ALLOWED}
+            {error, ?msg_pub_from_is_banned, ?DELIVER_NOT_ALLOWED}
     end.
 
 'check_prefixed_$_with_wildcard'({Msg, Topic} = Input, _) ->
     case emqx_topic:match(Msg#message.topic, Topic) of
         false ->
             ?tp(
-                notice,
+                debug,
                 ignore_retained_message_deliver,
                 #{
-                    reason => topic_not_match,
+                    reason => ?msg_topic_not_match,
                     msg_topic => Msg#message.topic,
                     subscribed_topic => Topic
                 }
             ),
-            {error, topic_not_match, ?DELIVER_NOT_ALLOWED};
+            {error, ?msg_topic_not_match, ?DELIVER_NOT_ALLOWED};
         true ->
             {ok, Input, ?DELIVER_ALLOWED}
     end.