Cache types in ConstructorMapper

jdbi · Feb 23, 2024 · 2da68e8 · 2da68e8
1 parent a70848f
commit 2da68e8
Showing 1 changed file with 12 additions and 7 deletions.
diff --git a/core/src/main/java/org/jdbi/v3/core/mapper/reflect/ConstructorInstanceFactory.java b/core/src/main/java/org/jdbi/v3/core/mapper/reflect/ConstructorInstanceFactory.java
@@ -19,6 +19,8 @@
 import java.lang.reflect.Parameter;
 import java.lang.reflect.Type;
 import java.util.Arrays;
+import java.util.Map;
+import java.util.concurrent.ConcurrentHashMap;
 import java.util.function.Supplier;
 import java.util.stream.Stream;
 
@@ -27,19 +29,18 @@
 import static java.util.Objects.requireNonNull;
 
 class ConstructorInstanceFactory<T> extends InstanceFactory<T> {
-    private final Constructor<T> constructor;
+    private static final Map<Constructor, Type[]> CONSTRUCTOR_CACHE = new ConcurrentHashMap<>();
 
-    private final Supplier<Type[]> typeSupplier;
+    private final Constructor<T> constructor;
 
     ConstructorInstanceFactory(Constructor<T> constructor) {
         super(constructor);
         this.constructor = requireNonNull(constructor, "constructor is null");
-        this.typeSupplier = getTypeSupplier(constructor, super::getTypes);
     }
 
     @Override
     Type[] getTypes() {
-        return typeSupplier.get();
+        return getTypes(constructor, super::getTypes);
     }
 
     @Override
@@ -76,13 +77,17 @@ private static <T> boolean isGenericInformationLost(Constructor<T> factory) {
         return lossDetected;
     }
 
-    private static <T> Supplier<Type[]> getTypeSupplier(Constructor<T> constructor, Supplier<Type[]> defaultSupplier) {
+    private static <T> Type[] getTypes(Constructor<T> constructor, Supplier<Type[]> defaultSupplier) {
+        return CONSTRUCTOR_CACHE.computeIfAbsent(constructor, ctor -> computeTypes(ctor, defaultSupplier));
+    }
+
+    private static <T> Type[] computeTypes(Constructor<T> constructor, Supplier<Type[]> defaultSupplier) {
         if (isGenericInformationLost(constructor)) {
-            return () -> getFields(constructor)
+            return getFields(constructor)
                 .map(Field::getGenericType)
                 .toArray(Type[]::new);
         }
-        return defaultSupplier;
+        return defaultSupplier.get();
     }
 
     private static <T> Stream<Field> getFields(Constructor<T> constructor) {