From 5f8c7f1f3755d98aa4e4d1321c8c3b3a03c8931d Mon Sep 17 00:00:00 2001
From: franz1981 <nigro.fra@gmail.com>
Date: Wed, 21 Jun 2023 10:49:21 +0200
Subject: [PATCH] findResourceWriters often creates HashSets and ArrayLists
 while not necessary

---
 .../jboss/resteasy/reactive/common/core/Serialisers.java   | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/independent-projects/resteasy-reactive/common/runtime/src/main/java/org/jboss/resteasy/reactive/common/core/Serialisers.java b/independent-projects/resteasy-reactive/common/runtime/src/main/java/org/jboss/resteasy/reactive/common/core/Serialisers.java
index 18cbc955d960fe..2280983015cdb9 100644
--- a/independent-projects/resteasy-reactive/common/runtime/src/main/java/org/jboss/resteasy/reactive/common/core/Serialisers.java
+++ b/independent-projects/resteasy-reactive/common/runtime/src/main/java/org/jboss/resteasy/reactive/common/core/Serialisers.java
@@ -164,7 +164,7 @@ protected List<ResourceWriter> findResourceWriters(QuarkusMultivaluedMap<Class<?
         List<ResourceWriter> ret = new ArrayList<>();
         Deque<Class<?>> toProcess = new LinkedList<>();
         do {
-            if (currentClass == Object.class) {
+            if (currentClass == Object.class && !toProcess.isEmpty()) {
                 //spec extension, look for interfaces as well
                 //we match interfaces before Object
                 Set<Class<?>> seen = new HashSet<>(toProcess);
@@ -182,13 +182,16 @@ protected List<ResourceWriter> findResourceWriters(QuarkusMultivaluedMap<Class<?
             }
             List<ResourceWriter> goodTypeWriters = writers.get(currentClass);
             writerLookup(runtimeType, produces, desired, ret, goodTypeWriters);
-            toProcess.addAll(Arrays.asList(currentClass.getInterfaces()));
+            var prevClass = currentClass;
             // if we're an interface, pretend our superclass is Object to get us through the same logic as a class
             if (currentClass.isInterface()) {
                 currentClass = Object.class;
             } else {
                 currentClass = currentClass.getSuperclass();
             }
+            if (currentClass != null) {
+                toProcess.addAll(List.of(prevClass.getInterfaces()));
+            }
         } while (currentClass != null);
 
         return ret;