Revert "Gjoranv/remove default ctor4"

1 files changed, 49 insertions, 11 deletions

diff --git a/config-model/src/main/java/com/yahoo/vespa/model/InstanceResolver.java b/config-model/src/main/java/com/yahoo/vespa/model/InstanceResolver.java
index fdb9fdf9796..9c761e425a7 100644
--- a/config-model/src/main/java/com/yahoo/vespa/model/InstanceResolver.java
+++ b/config-model/src/main/java/com/yahoo/vespa/model/InstanceResolver.java
@@ -11,7 +11,6 @@ import com.yahoo.vespa.config.buildergen.ConfigDefinition;
 import com.yahoo.yolean.Exceptions;
 import com.yahoo.vespa.config.*;
 
-import java.lang.reflect.Constructor;
 import java.lang.reflect.Field;
 import java.lang.reflect.Method;
 import java.util.List;
@@ -47,19 +46,13 @@ class InstanceResolver {
      * @param targetDef the def to use
      * @return the config instance or null of no producer for this found in model
      */
-    @SuppressWarnings("unchecked")
     static ConfigInstance resolveToInstance(ConfigKey<?> key, ConfigBuilder builder, InnerCNode targetDef) {
+        ConfigDefinitionKey defKey = new ConfigDefinitionKey(key);
         try {
             if (targetDef != null) applyDef(builder, targetDef);
-            Class<?> clazz = builder.getClass().getEnclosingClass();
-            if (!(ConfigInstance.class.isAssignableFrom(clazz))) {
-                throw new ConfigurationRuntimeException("Cannot produce config for the name '" + key.getName() + ", as "
-                                                                + clazz.getName() + " is not a ConfigInstance.");
-            }
-            Class<? extends ConfigInstance> configClass = (Class<? extends ConfigInstance>)clazz;
-            Constructor<? extends ConfigInstance> constructor = configClass.getDeclaredConstructor(builder.getClass(), boolean.class);
-            constructor.setAccessible(true);
-            return constructor.newInstance(builder, /*throwIfUninitialized*/ false);
+            ConfigInstance instance = getInstance(defKey, builder.getClass().getClassLoader());
+            Class<? extends ConfigInstance> clazz = instance.getClass();
+            return clazz.getConstructor(new Class<?>[]{builder.getClass()}).newInstance(builder);
         } catch (Exception e) {
             throw new ConfigurationRuntimeException(e);
         }
@@ -150,6 +143,51 @@ class InstanceResolver {
         }
     }
 
+    /**
+     * Create a ConfigBuilder given a definition key and a payload
+     * @param key The key to use to create the correct builder.
+     * @param payload The payload to populate the builder with.
+     * @return A ConfigBuilder initialized with payload.
+     */
+    static ConfigBuilder createBuilderFromPayload(ConfigDefinitionKey key, VespaModel model, ConfigPayload payload, ConfigDefinition targetDef) {
+        ConfigBuilder builderInstance = model.createBuilder(key, targetDef);
+        if (builderInstance == null || builderInstance instanceof GenericConfig.GenericConfigBuilder) {
+            if (log.isLoggable(LogLevel.SPAM)) {
+                log.log(LogLevel.SPAM, "Creating generic builder for key=" + key);
+            }
+            return new GenericConfig.GenericConfigBuilder(key, new ConfigPayloadBuilder(payload));
+        }
+        ConfigTransformer transformer = new ConfigTransformer(builderInstance.getClass().getDeclaringClass());
+        return transformer.toConfigBuilder(payload);
+    }
+
+    /**
+     * Returns a {@link ConfigInstance} of right type for given key using reflection
+     *
+     * @param  cKey a ConfigKey
+     * @return a {@link ConfigInstance} or null if not available in classpath
+     */
+    static ConfigInstance getInstance(ConfigDefinitionKey cKey, ClassLoader instanceLoader) {
+        String className = ConfigGenerator.createClassName(cKey.getName());
+        Class<?> clazz;
+        String fullClassName = packageName(cKey) + "." + className;
+        try {
+            clazz = instanceLoader != null ? instanceLoader.loadClass(fullClassName) : Class.forName(fullClassName);
+        } catch (ClassNotFoundException e) {
+            return null;
+        }
+        Object i;
+        try {
+            i = clazz.newInstance();
+        } catch (InstantiationException | IllegalAccessException e) {
+            throw new ConfigurationRuntimeException(e);
+        }
+        if (!(i instanceof ConfigInstance)) {
+            throw new ConfigurationRuntimeException(fullClassName + " is not a ConfigInstance, can not produce config for the name '" + cKey.getName() + "'.");
+        }
+        return (ConfigInstance) i;
+    }
+
     static String packageName(ConfigDefinitionKey cKey) {
         String prefix = "com.yahoo.";
         return prefix + (cKey.getNamespace().isEmpty() ? CNode.DEFAULT_NAMESPACE : cKey.getNamespace());