Cache types in ConstructorMapper

jdbi · Feb 22, 2024 · bb0bd84 · bb0bd84
1 parent a70848f
commit bb0bd84
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Showing 2 changed files with 13 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
@@ -26,20 +26,19 @@
 
 import static java.util.Objects.requireNonNull;
 
+import static org.jdbi.v3.core.mapper.reflect.ConstructorMapper.CONSTRUCTOR_CACHE;
+
 class ConstructorInstanceFactory<T> extends InstanceFactory<T> {
     private final Constructor<T> constructor;
 
-    private final Supplier<Type[]> typeSupplier;
-
     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 +75,17 @@ 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 -> getTypeSupplier(ctor, defaultSupplier));
+    }
+
+    private static <T> Type[] getTypeSupplier(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) {

diff --git a/core/src/main/java/org/jdbi/v3/core/mapper/reflect/ConstructorMapper.java b/core/src/main/java/org/jdbi/v3/core/mapper/reflect/ConstructorMapper.java
@@ -75,6 +75,9 @@ public final class ConstructorMapper<T> implements RowMapper<T> {
             + "that your result set has the columns expected, annotate the "
             + "parameter names explicitly with @ColumnName, or annotate nullable parameters as @Nullable";
 
+
+    static final Map<Constructor, Type[]> CONSTRUCTOR_CACHE = new ConcurrentHashMap<>();
+
     /**
      * Use the only declared constructor to map a class.
      *