Skip native prop metadata for delegate-backed managers (#59296)

Summary:

Add the default-off `skipNativePropsForViewManagerWithDelegateAndroid` feature flag. When enabled, `ViewManager.getNativeProps()` returns an empty map for managers with a non-null, non-generic delegate, avoiding unused manager and shadow-node prop metadata generation. Return a fresh mutable map so subclasses can safely extend `super.getNativeProps()`. The constants helper already omits `NativeProps` for an empty map; commands, events and custom constants are preserved.

Null and generic delegates keep the existing metadata path, including its legacy-architecture shadow-node handling. The flag must only be enabled when delegate-backed components use static view configs rather than runtime native prop metadata.

NativeProps queries reuse `getOrCreateViewManagerDelegate()`, sharing the same delegate with prop updates and commands. Make its lazy initialisation thread-safe with a volatile cache and double-checked synchronisation, leaving warm reads lock-free. Document that initialisation may occur on the JavaScript thread when this flag is enabled.

Regenerate all feature-flag bindings and cover enabled/disabled paths, generic and null delegates, marker-only managers, preserved constants, subclass prop extensions, independent mutable maps, existing-cache reuse and concurrent metadata/command initialisation.

Changelog:
[Android][Changed] - Add an opt-in optimisation to skip native prop metadata for delegate-backed view managers using static view configs.

Reviewed By: andrewdacenko

Differential Revision: D126630163

Author: javache

packages/react-native/ReactAndroid/src/main/java/com/facebook/react/internal/featureflags/ReactNativeFeatureFlags.kt

@@ -4,7 +4,7 @@
  * This source code is licensed under the MIT license found in the
  * LICENSE file in the root directory of this source tree.
  *
- * @generated SignedSource<<a89ede36c4631b7a7709899858a7f9c9>>
+ * @generated SignedSource<<251ba53185bdf10220816b4c239ef6d5>>
  */
 
 /**
@@ -510,6 +510,12 @@ public object ReactNativeFeatureFlags {
   @JvmStatic
   public fun skipActivityIdentityAssertionOnHostPause(): Boolean = accessor.skipActivityIdentityAssertionOnHostPause()
 
+  /**
+   * Skip native prop metadata generation on Android for view managers with custom delegates. Requires their components to use static view configs.
+   */
+  @JvmStatic
+  public fun skipNativePropsForViewManagerWithDelegateAndroid(): Boolean = accessor.skipNativePropsForViewManagerWithDelegateAndroid()
+
   /**
    * When a node changes, the differ leaves out its children that are unchanged in both trees instead of describing and comparing them.
    */

packages/react-native/ReactAndroid/src/main/java/com/facebook/react/internal/featureflags/ReactNativeFeatureFlagsCxxAccessor.kt

@@ -4,7 +4,7 @@
  * This source code is licensed under the MIT license found in the
  * LICENSE file in the root directory of this source tree.
  *
- * @generated SignedSource<<cd3b4f6a7fb4e616d3f56ab8c9eb9658>>
+ * @generated SignedSource<<1bb0fee5a17f70b91f33850d97479cc1>>
  */
 
 /**
@@ -100,6 +100,7 @@ internal class ReactNativeFeatureFlagsCxxAccessor : ReactNativeFeatureFlagsAcces
   private var shouldPressibilityUseW3CPointerEventsForHoverCache: Boolean? = null
   private var shouldTriggerResponderTransferOnScrollAndroidCache: Boolean? = null
   private var skipActivityIdentityAssertionOnHostPauseCache: Boolean? = null
+  private var skipNativePropsForViewManagerWithDelegateAndroidCache: Boolean? = null
   private var skipUnchangedChildrenInDifferentiatorCache: Boolean? = null
   private var syncAndroidClipBoundsWithOverflowCache: Boolean? = null
   private var traceTurboModulePromiseRejectionsOnAndroidCache: Boolean? = null
@@ -838,6 +839,15 @@ internal class ReactNativeFeatureFlagsCxxAccessor : ReactNativeFeatureFlagsAcces
     return cached
   }
 
+  override fun skipNativePropsForViewManagerWithDelegateAndroid(): Boolean {
+    var cached = skipNativePropsForViewManagerWithDelegateAndroidCache
+    if (cached == null) {
+      cached = ReactNativeFeatureFlagsCxxInterop.skipNativePropsForViewManagerWithDelegateAndroid()
+      skipNativePropsForViewManagerWithDelegateAndroidCache = cached
+    }
+    return cached
+  }
+
   override fun skipUnchangedChildrenInDifferentiator(): Boolean {
     var cached = skipUnchangedChildrenInDifferentiatorCache
     if (cached == null) {

packages/react-native/ReactAndroid/src/main/java/com/facebook/react/internal/featureflags/ReactNativeFeatureFlagsCxxInterop.kt

@@ -4,7 +4,7 @@
  * This source code is licensed under the MIT license found in the
  * LICENSE file in the root directory of this source tree.
  *
- * @generated SignedSource<<6d86d4adbc261c9271b5bed72bd12dcf>>
+ * @generated SignedSource<<8686d1f71576023f0cd22aca37b2e8ba>>
  */
 
 /**
@@ -188,6 +188,8 @@ public object ReactNativeFeatureFlagsCxxInterop {
 
   @DoNotStrip @JvmStatic public external fun skipActivityIdentityAssertionOnHostPause(): Boolean
 
+  @DoNotStrip @JvmStatic public external fun skipNativePropsForViewManagerWithDelegateAndroid(): Boolean
+
   @DoNotStrip @JvmStatic public external fun skipUnchangedChildrenInDifferentiator(): Boolean
 
   @DoNotStrip @JvmStatic public external fun syncAndroidClipBoundsWithOverflow(): Boolean

packages/react-native/ReactAndroid/src/main/java/com/facebook/react/internal/featureflags/ReactNativeFeatureFlagsDefaults.kt

@@ -4,7 +4,7 @@
  * This source code is licensed under the MIT license found in the
  * LICENSE file in the root directory of this source tree.
  *
- * @generated SignedSource<<a1368426dd823245c54b4312ae7b14e6>>
+ * @generated SignedSource<<09945e5bc899957424ce20441022830c>>
  */
 
 /**
@@ -183,6 +183,8 @@ public open class ReactNativeFeatureFlagsDefaults : ReactNativeFeatureFlagsProvi
 
   override fun skipActivityIdentityAssertionOnHostPause(): Boolean = false
 
+  override fun skipNativePropsForViewManagerWithDelegateAndroid(): Boolean = false
+
   override fun skipUnchangedChildrenInDifferentiator(): Boolean = false
 
   override fun syncAndroidClipBoundsWithOverflow(): Boolean = false

packages/react-native/ReactAndroid/src/main/java/com/facebook/react/internal/featureflags/ReactNativeFeatureFlagsLocalAccessor.kt

@@ -4,7 +4,7 @@
  * This source code is licensed under the MIT license found in the
  * LICENSE file in the root directory of this source tree.
  *
- * @generated SignedSource<<c305274be2fc6720b6c0eb75e78bd6b0>>
+ * @generated SignedSource<<12dd3ead4fa496af154f770cabc252f1>>
  */
 
 /**
@@ -104,6 +104,7 @@ internal class ReactNativeFeatureFlagsLocalAccessor : ReactNativeFeatureFlagsAcc
   private var shouldPressibilityUseW3CPointerEventsForHoverCache: Boolean? = null
   private var shouldTriggerResponderTransferOnScrollAndroidCache: Boolean? = null
   private var skipActivityIdentityAssertionOnHostPauseCache: Boolean? = null
+  private var skipNativePropsForViewManagerWithDelegateAndroidCache: Boolean? = null
   private var skipUnchangedChildrenInDifferentiatorCache: Boolean? = null
   private var syncAndroidClipBoundsWithOverflowCache: Boolean? = null
   private var traceTurboModulePromiseRejectionsOnAndroidCache: Boolean? = null
@@ -922,6 +923,16 @@ internal class ReactNativeFeatureFlagsLocalAccessor : ReactNativeFeatureFlagsAcc
     return cached
   }
 
+  override fun skipNativePropsForViewManagerWithDelegateAndroid(): Boolean {
+    var cached = skipNativePropsForViewManagerWithDelegateAndroidCache
+    if (cached == null) {
+      cached = currentProvider.skipNativePropsForViewManagerWithDelegateAndroid()
+      accessedFeatureFlags.add("skipNativePropsForViewManagerWithDelegateAndroid")
+      skipNativePropsForViewManagerWithDelegateAndroidCache = cached
+    }
+    return cached
+  }
+
   override fun skipUnchangedChildrenInDifferentiator(): Boolean {
     var cached = skipUnchangedChildrenInDifferentiatorCache
     if (cached == null) {

packages/react-native/ReactAndroid/src/main/java/com/facebook/react/internal/featureflags/ReactNativeFeatureFlagsProvider.kt

@@ -4,7 +4,7 @@
  * This source code is licensed under the MIT license found in the
  * LICENSE file in the root directory of this source tree.
  *
- * @generated SignedSource<<da45e41e9a58711ee3b68a38965938fb>>
+ * @generated SignedSource<<8227961bd327cc2851437304b21dee6a>>
  */
 
 /**
@@ -183,6 +183,8 @@ public interface ReactNativeFeatureFlagsProvider {
 
   @DoNotStrip public fun skipActivityIdentityAssertionOnHostPause(): Boolean
 
+  @DoNotStrip public fun skipNativePropsForViewManagerWithDelegateAndroid(): Boolean
+
   @DoNotStrip public fun skipUnchangedChildrenInDifferentiator(): Boolean
 
   @DoNotStrip public fun syncAndroidClipBoundsWithOverflow(): Boolean

packages/react-native/ReactAndroid/src/main/java/com/facebook/react/uimanager/ViewManager.java

@@ -46,7 +46,7 @@ public abstract class ViewManager<T extends View, C extends ReactShadowNode<?>>
 
   private static final String TAG = "ViewManager";
 
-  private @Nullable ViewManagerDelegate<T> mDelegate = null;
+  private volatile @Nullable ViewManagerDelegate<T> mDelegate = null;
 
   /**
    * For View recycling: we store a Stack of unused, dead Views. This is null by default, and when
@@ -113,6 +113,11 @@ public void updateProperties(@NonNull T viewToUpdate, ReactStylesDiffMap props)
    * <p>By default, this methods returns a generic {@link ViewManagerDelegate} which uses {@link
    * ViewManagerSetter} to apply property updates.
    *
+   * <p>When {@code skipNativePropsForViewManagerWithDelegateAndroid} is enabled, lazy delegate
+   * initialisation may also occur during native prop metadata generation on the JavaScript thread.
+   * The returned delegate is cached and shared with subsequent prop updates and commands. Overrides
+   * must be safe to initialise on either thread.
+   *
    * @return an instance of {@link ViewManagerDelegate} if the props of the view managed by this
    *     view manager should be set via this delegate
    */
@@ -131,8 +136,13 @@ protected ViewManagerDelegate<T> getDelegate() {
   private ViewManagerDelegate<T> getOrCreateViewManagerDelegate() {
     ViewManagerDelegate<T> delegate = mDelegate;
     if (delegate == null) {
-      delegate = getDelegate();
-      mDelegate = delegate;
+      synchronized (this) {
+        delegate = mDelegate;
+        if (delegate == null) {
+          delegate = getDelegate();
+          mDelegate = delegate;
+        }
+      }
     }
     return delegate;
   }
@@ -402,10 +412,21 @@ public void receiveCommand(@NonNull T view, String commandId, ReadableArray args
   }
 
   /**
-   * Returns a {@link Map<String, String>} representing the native props of the view manager. The
-   * Map contains the names (key) and types (value) of the ViewManager's props.
+   * Returns a mutable {@link Map<String, String>} representing the native props of the view
+   * manager. The Map contains the names (key) and types (value) of the ViewManager's props.
+   *
+   * <p>When {@code skipNativePropsForViewManagerWithDelegateAndroid} is enabled, managers with a
+   * non-generic delegate return an empty map. Enable this only when those components use static
+   * view configs rather than deriving their valid attributes from native prop metadata.
    */
   public Map<String, String> getNativeProps() {
+    if (ReactNativeFeatureFlags.skipNativePropsForViewManagerWithDelegateAndroid()) {
+      ViewManagerDelegate<T> delegate = getOrCreateViewManagerDelegate();
+      if (delegate != null
+          && !(delegate instanceof ViewManagerPropertyUpdater.GenericViewManagerDelegate)) {
+        return new HashMap<>();
+      }
+    }
     if (ReactBuildConfig.UNSTABLE_ENABLE_MINIFY_LEGACY_ARCHITECTURE
         && ReactNativeNewArchitectureFeatureFlags.enableBridgelessArchitecture()) {
       // TODO: review if we need to check fabricInterop here

packages/react-native/ReactAndroid/src/main/jni/react/featureflags/JReactNativeFeatureFlagsCxxInterop.cpp

@@ -4,7 +4,7 @@
  * This source code is licensed under the MIT license found in the
  * LICENSE file in the root directory of this source tree.
  *
- * @generated SignedSource<<944781e7a547e601f0637869a3a3ec5e>>
+ * @generated SignedSource<<223e38a173e3762fa0034ed47f96a84d>>
  */
 
 /**
@@ -519,6 +519,12 @@ class ReactNativeFeatureFlagsJavaProvider
     return method(javaProvider_);
   }
 
+  bool skipNativePropsForViewManagerWithDelegateAndroid() override {
+    static const auto method =
+        getReactNativeFeatureFlagsProviderJavaClass()->getMethod<jboolean()>("skipNativePropsForViewManagerWithDelegateAndroid");
+    return method(javaProvider_);
+  }
+
   bool skipUnchangedChildrenInDifferentiator() override {
     static const auto method =
         getReactNativeFeatureFlagsProviderJavaClass()->getMethod<jboolean()>("skipUnchangedChildrenInDifferentiator");
@@ -1025,6 +1031,11 @@ bool JReactNativeFeatureFlagsCxxInterop::skipActivityIdentityAssertionOnHostPaus
   return ReactNativeFeatureFlags::skipActivityIdentityAssertionOnHostPause();
 }
 
+bool JReactNativeFeatureFlagsCxxInterop::skipNativePropsForViewManagerWithDelegateAndroid(
+    facebook::jni::alias_ref<JReactNativeFeatureFlagsCxxInterop> /*unused*/) {
+  return ReactNativeFeatureFlags::skipNativePropsForViewManagerWithDelegateAndroid();
+}
+
 bool JReactNativeFeatureFlagsCxxInterop::skipUnchangedChildrenInDifferentiator(
     facebook::jni::alias_ref<JReactNativeFeatureFlagsCxxInterop> /*unused*/) {
   return ReactNativeFeatureFlags::skipUnchangedChildrenInDifferentiator();
@@ -1381,6 +1392,9 @@ void JReactNativeFeatureFlagsCxxInterop::registerNatives() {
       makeNativeMethod(
         "skipActivityIdentityAssertionOnHostPause",
         JReactNativeFeatureFlagsCxxInterop::skipActivityIdentityAssertionOnHostPause),
+      makeNativeMethod(
+        "skipNativePropsForViewManagerWithDelegateAndroid",
+        JReactNativeFeatureFlagsCxxInterop::skipNativePropsForViewManagerWithDelegateAndroid),
       makeNativeMethod(
         "skipUnchangedChildrenInDifferentiator",
         JReactNativeFeatureFlagsCxxInterop::skipUnchangedChildrenInDifferentiator),

packages/react-native/ReactAndroid/src/main/jni/react/featureflags/JReactNativeFeatureFlagsCxxInterop.h

@@ -4,7 +4,7 @@
  * This source code is licensed under the MIT license found in the
  * LICENSE file in the root directory of this source tree.
  *
- * @generated SignedSource<<ad9275a6afb74520bec7d446faafd1bc>>
+ * @generated SignedSource<<fbe2d936391c1d25f9741753c952dfdb>>
  */
 
 /**
@@ -270,6 +270,9 @@ class JReactNativeFeatureFlagsCxxInterop
   static bool skipActivityIdentityAssertionOnHostPause(
     facebook::jni::alias_ref<JReactNativeFeatureFlagsCxxInterop>);
 
+  static bool skipNativePropsForViewManagerWithDelegateAndroid(
+    facebook::jni::alias_ref<JReactNativeFeatureFlagsCxxInterop>);
+
   static bool skipUnchangedChildrenInDifferentiator(
     facebook::jni::alias_ref<JReactNativeFeatureFlagsCxxInterop>);