Reduce the amount of C++ code in user space for RN-Tester

Summary:
This diff reduces the amount of C++ code in user space by:
- Moving all the C++ implementation of the .defaults package inside a `react_newarchdefaults` shared library
- Exposing only the entrypoint logic inside the RN-Tester's `OnLoad.cpp` file.

Changelog:
[Android] [Changed] - Reduce the amount of C++ code in user space for New Architecture

Reviewed By: cipolleschi

Differential Revision: D39381820

fbshipit-source-id: 9c4b5596b67b5a7ee58824319c80e325348ed06c

ReactAndroid/src/main/java/com/facebook/react/defaults/DefaultComponentsRegistry.kt

@@ -15,9 +15,8 @@ import com.facebook.react.fabric.ComponentFactory
  * A utility class that provides users a ComponentRegistry they can customize with a C++
  * implementation of its native methods.
  *
- * Please note that you need to provide a native implementation for the method initHybrid for this
- * class, making sure the Java Descriptor is:
- * Lcom/facebook/react/defaults/DefaultComponentsRegistry;
+ * This class works together with the [DefaultNativeEntryPoint] and it's C++ implementation is
+ * hosted inside the React Native framwork
  */
 @DoNotStrip
 class DefaultComponentsRegistry

ReactAndroid/src/main/java/com/facebook/react/defaults/DefaultNativeEntryPoint.kt

@@ -0,0 +1,39 @@
+/*
+ * Copyright (c) Meta Platforms, Inc. and affiliates.
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ */
+
+package com.facebook.react.defaults
+
+import com.facebook.jni.HybridData
+import com.facebook.proguard.annotations.DoNotStrip
+import com.facebook.soloader.SoLoader
+
+/**
+ * A utility class that serves as an entry point for users to register all the custom Fabric
+ * Components and Turbo Native Modules.
+ *
+ * This class needs to be invoked as `DefaultNativeEntryPoint.load("...")` by passing the name of
+ * the dynamic library to load.
+ *
+ * This class works together with the [DefaultNativeEntryPoint] and it's C++ implementation is
+ * hosted inside the React Native framework
+ */
+@DoNotStrip
+class DefaultNativeEntryPoint @DoNotStrip private constructor() {
+
+  @DoNotStrip private val hybridData: HybridData = initHybrid()
+
+  @DoNotStrip private external fun initHybrid(): HybridData
+
+  companion object {
+    @JvmStatic
+    fun load(dynamicLibraryName: String) {
+      SoLoader.loadLibrary("react_newarchdefaults")
+      SoLoader.loadLibrary(dynamicLibraryName)
+      DefaultNativeEntryPoint()
+    }
+  }
+}

ReactAndroid/src/main/java/com/facebook/react/defaults/DefaultTurboModuleManagerDelegate.kt

@@ -17,9 +17,8 @@ import com.facebook.react.bridge.ReactApplicationContext
  * A utility class that allows you to simplify the setup of a
  * [ReactPackageTurboModuleManagerDelegate] for new apps in Open Source.
  *
- * Please note that you need to provide a native implementation for the method initHybrid for this
- * class, making sure the Java Descriptor is:
- * Lcom/facebook/react/defaults/DefaultTurboModuleManagerDelegate;
+ * This class works together with the [DefaultNativeEntryPoint] and it's C++ implementation is
+ * hosted inside the React Native framwork
  */
 class DefaultTurboModuleManagerDelegate
 private constructor(context: ReactApplicationContext, packages: List<ReactPackage>) :

ReactAndroid/src/main/jni/CMakeLists.txt

@@ -101,6 +101,7 @@ add_react_android_subdir(src/main/jni/react/uimanager)
 add_react_android_subdir(src/main/jni/react/mapbuffer)
 add_react_android_subdir(src/main/jni/react/reactnativeblob)
 add_react_android_subdir(src/main/jni/react/fabric)
+add_react_android_subdir(src/main/jni/react/newarchdefaults)
 add_react_android_subdir(src/main/jni/react/hermes/reactexecutor)
 add_react_android_subdir(src/main/jni/react/hermes/instrumentation/)
 

ReactAndroid/src/main/jni/react/newarchdefaults/CMakeLists.txt

@@ -0,0 +1,22 @@
+# Copyright (c) Meta Platforms, Inc. and affiliates.
+#
+# This source code is licensed under the MIT license found in the
+# LICENSE file in the root directory of this source tree.
+
+cmake_minimum_required(VERSION 3.13)
+set(CMAKE_VERBOSE_MAKEFILE on)
+
+add_compile_options(-fexceptions -frtti -std=c++17 -Wall -DLOG_TAG=\"ReactNative\")
+
+file(GLOB react_newarchdefaults_SRC CONFIGURE_DEPENDS *.cpp)
+
+add_library(react_newarchdefaults SHARED ${react_newarchdefaults_SRC})
+
+target_include_directories(react_newarchdefaults PUBLIC .)
+
+target_link_libraries(react_newarchdefaults
+        fbjni
+        fabricjni
+        react_nativemodule_core
+        react_codegen_rncore
+        jsi)

ReactAndroid/src/main/jni/react/newarchdefaults/DefaultComponentsRegistry.cpp

@@ -0,0 +1,70 @@
+/*
+ * Copyright (c) Meta Platforms, Inc. and affiliates.
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ */
+
+#include "DefaultComponentsRegistry.h"
+
+#include <CoreComponentsRegistry.h>
+#include <fbjni/fbjni.h>
+#include <react/renderer/componentregistry/ComponentDescriptorProviderRegistry.h>
+#include <react/renderer/components/rncore/ComponentDescriptors.h>
+
+namespace facebook {
+namespace react {
+
+std::function<void(std::shared_ptr<ComponentDescriptorProviderRegistry const>)>
+    DefaultComponentsRegistry::registerComponentDescriptorsFromEntryPoint{};
+
+DefaultComponentsRegistry::DefaultComponentsRegistry(ComponentFactory *delegate)
+    : delegate_(delegate) {}
+
+std::shared_ptr<ComponentDescriptorProviderRegistry const>
+DefaultComponentsRegistry::sharedProviderRegistry() {
+  auto providerRegistry = CoreComponentsRegistry::sharedProviderRegistry();
+
+  (DefaultComponentsRegistry::registerComponentDescriptorsFromEntryPoint)(
+      providerRegistry);
+
+  return providerRegistry;
+}
+
+jni::local_ref<DefaultComponentsRegistry::jhybriddata>
+DefaultComponentsRegistry::initHybrid(
+    jni::alias_ref<jclass>,
+    ComponentFactory *delegate) {
+  auto instance = makeCxxInstance(delegate);
+
+  auto buildRegistryFunction =
+      [](EventDispatcher::Weak const &eventDispatcher,
+         ContextContainer::Shared const &contextContainer)
+      -> ComponentDescriptorRegistry::Shared {
+    auto registry = DefaultComponentsRegistry::sharedProviderRegistry()
+                        ->createComponentDescriptorRegistry(
+                            {eventDispatcher, contextContainer});
+
+    auto mutableRegistry =
+        std::const_pointer_cast<ComponentDescriptorRegistry>(registry);
+
+    mutableRegistry->setFallbackComponentDescriptor(
+        std::make_shared<UnimplementedNativeViewComponentDescriptor>(
+            ComponentDescriptorParameters{
+                eventDispatcher, contextContainer, nullptr}));
+
+    return registry;
+  };
+
+  delegate->buildRegistryFunction = buildRegistryFunction;
+  return instance;
+}
+
+void DefaultComponentsRegistry::registerNatives() {
+  registerHybrid({
+      makeNativeMethod("initHybrid", DefaultComponentsRegistry::initHybrid),
+  });
+}
+
+} // namespace react
+} // namespace facebook

ReactAndroid/src/main/jni/react/newarchdefaults/DefaultComponentsRegistry.h

@@ -0,0 +1,47 @@
+/*
+ * Copyright (c) Meta Platforms, Inc. and affiliates.
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ */
+
+#pragma once
+
+#include <ComponentFactory.h>
+#include <fbjni/fbjni.h>
+#include <react/renderer/componentregistry/ComponentDescriptorProviderRegistry.h>
+#include <react/renderer/componentregistry/ComponentDescriptorRegistry.h>
+#include <react/renderer/core/ConcreteComponentDescriptor.h>
+
+namespace facebook {
+namespace react {
+
+class DefaultComponentsRegistry
+    : public facebook::jni::HybridClass<DefaultComponentsRegistry> {
+ public:
+  constexpr static auto kJavaDescriptor =
+      "Lcom/facebook/react/defaults/DefaultComponentsRegistry;";
+
+  static void registerNatives();
+
+  static std::function<void(
+      std::shared_ptr<ComponentDescriptorProviderRegistry const>)>
+      registerComponentDescriptorsFromEntryPoint;
+
+  DefaultComponentsRegistry(ComponentFactory *delegate);
+
+ private:
+  friend HybridBase;
+
+  static std::shared_ptr<ComponentDescriptorProviderRegistry const>
+  sharedProviderRegistry();
+
+  const ComponentFactory *delegate_;
+
+  static jni::local_ref<jhybriddata> initHybrid(
+      jni::alias_ref<jclass>,
+      ComponentFactory *delegate);
+};
+
+} // namespace react
+} // namespace facebook

ReactAndroid/src/main/jni/react/newarchdefaults/DefaultTurboModuleManagerDelegate.cpp

@@ -0,0 +1,51 @@
+/*
+ * Copyright (c) Meta Platforms, Inc. and affiliates.
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ */
+
+#include "DefaultTurboModuleManagerDelegate.h"
+
+#include <rncore.h>
+
+namespace facebook {
+namespace react {
+
+std::function<std::shared_ptr<TurboModule>(
+    const std::string &,
+    const JavaTurboModule::InitParams &)>
+    DefaultTurboModuleManagerDelegate::moduleProvidersFromEntryPoint{nullptr};
+
+jni::local_ref<DefaultTurboModuleManagerDelegate::jhybriddata>
+DefaultTurboModuleManagerDelegate::initHybrid(jni::alias_ref<jhybridobject>) {
+  return makeCxxInstance();
+}
+
+void DefaultTurboModuleManagerDelegate::registerNatives() {
+  registerHybrid({
+      makeNativeMethod(
+          "initHybrid", DefaultTurboModuleManagerDelegate::initHybrid),
+  });
+}
+
+std::shared_ptr<TurboModule> DefaultTurboModuleManagerDelegate::getTurboModule(
+    const std::string &name,
+    const std::shared_ptr<CallInvoker> &jsInvoker) {
+  // Not implemented yet: provide pure-C++ NativeModules here.
+  return nullptr;
+}
+
+std::shared_ptr<TurboModule> DefaultTurboModuleManagerDelegate::getTurboModule(
+    const std::string &name,
+    const JavaTurboModule::InitParams &params) {
+  auto resolvedModule = (DefaultTurboModuleManagerDelegate::
+                             moduleProvidersFromEntryPoint)(name, params);
+  if (resolvedModule != nullptr) {
+    return resolvedModule;
+  }
+  return rncore_ModuleProvider(name, params);
+}
+
+} // namespace react
+} // namespace facebook

ReactAndroid/src/main/jni/react/newarchdefaults/DefaultTurboModuleManagerDelegate.h

@@ -0,0 +1,48 @@
+/*
+ * Copyright (c) Meta Platforms, Inc. and affiliates.
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ */
+
+#include <memory>
+#include <string>
+
+#include <ReactCommon/JavaTurboModule.h>
+#include <ReactCommon/TurboModule.h>
+#include <ReactCommon/TurboModuleManagerDelegate.h>
+#include <fbjni/fbjni.h>
+
+namespace facebook {
+namespace react {
+
+class DefaultTurboModuleManagerDelegate : public jni::HybridClass<
+                                              DefaultTurboModuleManagerDelegate,
+                                              TurboModuleManagerDelegate> {
+ public:
+  static constexpr auto kJavaDescriptor =
+      "Lcom/facebook/react/defaults/DefaultTurboModuleManagerDelegate;";
+
+  static jni::local_ref<jhybriddata> initHybrid(jni::alias_ref<jhybridobject>);
+
+  static void registerNatives();
+
+  static std::function<std::shared_ptr<TurboModule>(
+      const std::string &,
+      const JavaTurboModule::InitParams &)>
+      moduleProvidersFromEntryPoint;
+
+  std::shared_ptr<TurboModule> getTurboModule(
+      const std::string &name,
+      const std::shared_ptr<CallInvoker> &jsInvoker) override;
+  std::shared_ptr<TurboModule> getTurboModule(
+      const std::string &name,
+      const JavaTurboModule::InitParams &params) override;
+
+ private:
+  friend HybridBase;
+  using HybridBase::HybridBase;
+};
+
+} // namespace react
+} // namespace facebook

ReactAndroid/src/main/jni/react/newarchdefaults/OnLoad.cpp

@@ -0,0 +1,18 @@
+/*
+ * Copyright (c) Meta Platforms, Inc. and affiliates.
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ */
+
+#include <fbjni/fbjni.h>
+
+#include "DefaultComponentsRegistry.h"
+#include "DefaultTurboModuleManagerDelegate.h"
+
+JNIEXPORT jint JNICALL JNI_OnLoad(JavaVM *vm, void *) {
+  return facebook::jni::initialize(vm, [] {
+    facebook::react::DefaultTurboModuleManagerDelegate::registerNatives();
+    facebook::react::DefaultComponentsRegistry::registerNatives();
+  });
+}