From 637202e463d4d976840fc7dcb64293fa9e65a454 Mon Sep 17 00:00:00 2001
From: zhongwencool <zhongwencool@gmail.com>
Date: Fri, 27 May 2022 11:04:49 +0800
Subject: [PATCH] fix: heap size is growing very fast when trace large msg

---
 src/emqx_packet.erl | 13 ++++++-------
 1 file changed, 6 insertions(+), 7 deletions(-)

diff --git a/src/emqx_packet.erl b/src/emqx_packet.erl
index 4665e7733..10ec4487b 100644
--- a/src/emqx_packet.erl
+++ b/src/emqx_packet.erl
@@ -442,18 +442,18 @@ format_header(#mqtt_packet_header{type = Type,
                                   dup = Dup,
                                   qos = QoS,
                                   retain = Retain}, S) ->
-    S1 = case S == undefined of
-             true -> <<>>;
-             false -> [", ", S]
-         end,
-    io_lib:format("~s(Q~p, R~p, D~p~s)", [type_name(Type), QoS, i(Retain), i(Dup), S1]).
+    Header = io_lib:format("~s(Q~p, R~p, D~p)", [type_name(Type), QoS, i(Retain), i(Dup)]),
+    case S == undefined of
+        true -> Header;
+        false -> [Header, S]
+    end.
 
 format_variable(undefined, _) ->
     undefined;
 format_variable(Variable, undefined) ->
     format_variable(Variable);
 format_variable(Variable, Payload) ->
-    io_lib:format("~s, Payload=~0p", [format_variable(Variable), Payload]).
+    [format_variable(Variable), ", Payload=", Payload].
 
 format_variable(#mqtt_packet_connect{
                  proto_ver    = ProtoVer,
@@ -520,4 +520,3 @@ format_password(_Password) -> '******'.
 i(true)  -> 1;
 i(false) -> 0;
 i(I) when is_integer(I) -> I.
-