Properly convert MemorySize to RESTEasy configuration

Some part of RESTEasy are using ResteasyConfigurationMPConfig to map the
config and we were incorrectly pushing the raw string for
quarkus.resteasy.gzip.max-input.

Fixes #39636

(cherry picked from commit bd4d294)

extensions/resteasy-classic/resteasy/runtime/src/main/java/io/quarkus/resteasy/runtime/standalone/ResteasyConfigurationMPConfig.java

@@ -1,35 +1,39 @@
 package io.quarkus.resteasy.runtime.standalone;
 
-import java.util.Collections;
 import java.util.HashSet;
 import java.util.Map;
 import java.util.Optional;
 import java.util.Set;
+import java.util.function.Function;
 
 import org.eclipse.microprofile.config.Config;
 import org.eclipse.microprofile.config.ConfigProvider;
 import org.jboss.resteasy.plugins.server.servlet.ResteasyContextParameters;
 import org.jboss.resteasy.spi.ResteasyConfiguration;
 
+import io.quarkus.runtime.configuration.MemorySize;
+
 /**
- * Some resteasy components use this class for configuration. This bridges MP Config to ResteasyConfiguration
+ * Some RESTEasy components use this class for configuration. This bridges MP Config to ResteasyConfiguration
  *
  */
 public class ResteasyConfigurationMPConfig implements ResteasyConfiguration {
 
-    private static final Map<String, String> RESTEASY_QUARKUS_MAPPING_PARAMS = Map.of(
-            ResteasyContextParameters.RESTEASY_GZIP_MAX_INPUT, "quarkus.resteasy.gzip.max-input");
+    private static final Map<String, Function<Config, Optional<String>>> RESTEASY_QUARKUS_MAPPING_PARAMS = Map.of(
+            ResteasyContextParameters.RESTEASY_GZIP_MAX_INPUT, ResteasyConfigurationMPConfig::getGzipMaxInput);
 
     @Override
     public String getParameter(String name) {
         Config config = ConfigProvider.getConfig();
-        if (config == null)
+        if (config == null) {
             return null;
+        }
+
         Optional<String> value = Optional.empty();
-        String mappedProperty = RESTEASY_QUARKUS_MAPPING_PARAMS.get(name);
-        if (mappedProperty != null) {
-            // try to use quarkus parameter
-            value = config.getOptionalValue(mappedProperty, String.class);
+        Function<Config, Optional<String>> mappingFunction = RESTEASY_QUARKUS_MAPPING_PARAMS.get(name);
+        if (mappingFunction != null) {
+            // try to use Quarkus configuration
+            value = mappingFunction.apply(config);
         }
 
         // if the parameter name is not mapped or there is no value, use the parameter name as provided
@@ -40,12 +44,15 @@ public String getParameter(String name) {
     @Override
     public Set<String> getParameterNames() {
         Config config = ConfigProvider.getConfig();
-        if (config == null)
-            return Collections.EMPTY_SET;
+        if (config == null) {
+            return Set.of();
+        }
         HashSet<String> set = new HashSet<>();
-        for (String name : config.getPropertyNames())
+        for (String name : config.getPropertyNames()) {
             set.add(name);
+        }
         set.addAll(RESTEASY_QUARKUS_MAPPING_PARAMS.keySet());
+
         return set;
     }
 
@@ -58,4 +65,14 @@ public String getInitParameter(String name) {
     public Set<String> getInitParameterNames() {
         return getParameterNames();
     }
+
+    private static Optional<String> getGzipMaxInput(Config config) {
+        Optional<MemorySize> rawValue = config.getOptionalValue("quarkus.resteasy.gzip.max-input", MemorySize.class);
+
+        if (rawValue.isEmpty()) {
+            return Optional.empty();
+        }
+
+        return Optional.of(Long.toString(rawValue.get().asLongValue()));
+    }
 }