do not pass state wrapper for text during view preallocation (#46418)

Summary:
Pull Request resolved: #46418

changelog: [internal]

introduce a small performance optimisation on Android.

When Paragraph is preallocated, it does not have valid C++ state. But we still send it to Android layer because it is part of a more generic pipeline. This has a cost because Android will end up using the state to update internal state on ReactTextView. To avoid this, simply add a special case to view preallocation and prevent it from sending C++ state.

Reviewed By: javache

Differential Revision: D62435529

fbshipit-source-id: 36b5b00a7a390432721d28d53ff8d4af76169e08

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<<312da6e350ea6b96180156a341810654>>
+ * @generated SignedSource<<b9b1988a78ba67a99027372dab215d06>>
  */
 
 /**
@@ -160,6 +160,12 @@ public object ReactNativeFeatureFlags {
   @JvmStatic
   public fun enableSynchronousStateUpdates(): Boolean = accessor.enableSynchronousStateUpdates()
 
+  /**
+   * Text preallocation optimisation where unnecessary work is removed.
+   */
+  @JvmStatic
+  public fun enableTextPreallocationOptimisation(): Boolean = accessor.enableTextPreallocationOptimisation()
+
   /**
    * Ensures that JavaScript always has a consistent view of the state of the UI (e.g.: commits done in other threads are not immediately propagated to JS during its execution).
    */

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<<a397b9b648fab0e8b1f9d8a9dba04ab4>>
+ * @generated SignedSource<<ae270cbe5e211d74cc056511be4ead16>>
  */
 
 /**
@@ -42,6 +42,7 @@ public class ReactNativeFeatureFlagsCxxAccessor : ReactNativeFeatureFlagsAccesso
   private var enablePropsUpdateReconciliationAndroidCache: Boolean? = null
   private var enableReportEventPaintTimeCache: Boolean? = null
   private var enableSynchronousStateUpdatesCache: Boolean? = null
+  private var enableTextPreallocationOptimisationCache: Boolean? = null
   private var enableUIConsistencyCache: Boolean? = null
   private var enableViewRecyclingCache: Boolean? = null
   private var excludeYogaFromRawPropsCache: Boolean? = null
@@ -268,6 +269,15 @@ public class ReactNativeFeatureFlagsCxxAccessor : ReactNativeFeatureFlagsAccesso
     return cached
   }
 
+  override fun enableTextPreallocationOptimisation(): Boolean {
+    var cached = enableTextPreallocationOptimisationCache
+    if (cached == null) {
+      cached = ReactNativeFeatureFlagsCxxInterop.enableTextPreallocationOptimisation()
+      enableTextPreallocationOptimisationCache = cached
+    }
+    return cached
+  }
+
   override fun enableUIConsistency(): Boolean {
     var cached = enableUIConsistencyCache
     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<<ba7f0d3c03fef86fb12e4d9842dcb241>>
+ * @generated SignedSource<<66a5f1eb19c081e178077b40fba27d93>>
  */
 
 /**
@@ -72,6 +72,8 @@ public object ReactNativeFeatureFlagsCxxInterop {
 
   @DoNotStrip @JvmStatic public external fun enableSynchronousStateUpdates(): Boolean
 
+  @DoNotStrip @JvmStatic public external fun enableTextPreallocationOptimisation(): Boolean
+
   @DoNotStrip @JvmStatic public external fun enableUIConsistency(): Boolean
 
   @DoNotStrip @JvmStatic public external fun enableViewRecycling(): 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<<fa8245a05ab1f508318e1d18938f9dab>>
+ * @generated SignedSource<<25a422b93ab27473bfccabf653b1e196>>
  */
 
 /**
@@ -67,6 +67,8 @@ public open class ReactNativeFeatureFlagsDefaults : ReactNativeFeatureFlagsProvi
 
   override fun enableSynchronousStateUpdates(): Boolean = false
 
+  override fun enableTextPreallocationOptimisation(): Boolean = false
+
   override fun enableUIConsistency(): Boolean = false
 
   override fun enableViewRecycling(): 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<<069787b84036b763c47d128e66ddd1ab>>
+ * @generated SignedSource<<d18208e5018340e48e3c20b6a80ecccd>>
  */
 
 /**
@@ -46,6 +46,7 @@ public class ReactNativeFeatureFlagsLocalAccessor : ReactNativeFeatureFlagsAcces
   private var enablePropsUpdateReconciliationAndroidCache: Boolean? = null
   private var enableReportEventPaintTimeCache: Boolean? = null
   private var enableSynchronousStateUpdatesCache: Boolean? = null
+  private var enableTextPreallocationOptimisationCache: Boolean? = null
   private var enableUIConsistencyCache: Boolean? = null
   private var enableViewRecyclingCache: Boolean? = null
   private var excludeYogaFromRawPropsCache: Boolean? = null
@@ -294,6 +295,16 @@ public class ReactNativeFeatureFlagsLocalAccessor : ReactNativeFeatureFlagsAcces
     return cached
   }
 
+  override fun enableTextPreallocationOptimisation(): Boolean {
+    var cached = enableTextPreallocationOptimisationCache
+    if (cached == null) {
+      cached = currentProvider.enableTextPreallocationOptimisation()
+      accessedFeatureFlags.add("enableTextPreallocationOptimisation")
+      enableTextPreallocationOptimisationCache = cached
+    }
+    return cached
+  }
+
   override fun enableUIConsistency(): Boolean {
     var cached = enableUIConsistencyCache
     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<<978d9e8d1129951f3c5750f95e2ff5d2>>
+ * @generated SignedSource<<2e20df15ed5c75e0749eeead23b3c9dc>>
  */
 
 /**
@@ -67,6 +67,8 @@ public interface ReactNativeFeatureFlagsProvider {
 
   @DoNotStrip public fun enableSynchronousStateUpdates(): Boolean
 
+  @DoNotStrip public fun enableTextPreallocationOptimisation(): Boolean
+
   @DoNotStrip public fun enableUIConsistency(): Boolean
 
   @DoNotStrip public fun enableViewRecycling(): Boolean

packages/react-native/ReactAndroid/src/main/jni/react/fabric/FabricMountingManager.cpp

@@ -847,7 +847,14 @@ void FabricMountingManager::preallocateShadowView(
   // We DO want to hold onto C object from Java, since we don't know the
   // lifetime of the Java object
   jni::local_ref<StateWrapperImpl::JavaPart> javaStateWrapper = nullptr;
-  if (shadowView.state != nullptr) {
+
+  // Paragraph only has a dummy state during view preallocation.
+  // Updating state on Android side has a cost and doing it unnecessarily for
+  // dummy state is wasteful.
+  bool preventPassingStateWrapperForText =
+      ReactNativeFeatureFlags::enableTextPreallocationOptimisation() &&
+      strcmp(shadowView.componentName, "Paragraph") == 0;
+  if (shadowView.state != nullptr && !preventPassingStateWrapperForText) {
     javaStateWrapper = StateWrapperImpl::newObjectJavaArgs();
     StateWrapperImpl* cStateWrapper = cthis(javaStateWrapper);
     cStateWrapper->setState(shadowView.state);

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<<63ef974f6ed666553bc0be593730a08e>>
+ * @generated SignedSource<<4ae4df54833e6fc817d73fe7cb7d1887>>
  */
 
 /**
@@ -171,6 +171,12 @@ class ReactNativeFeatureFlagsProviderHolder
     return method(javaProvider_);
   }
 
+  bool enableTextPreallocationOptimisation() override {
+    static const auto method =
+        getReactNativeFeatureFlagsProviderJavaClass()->getMethod<jboolean()>("enableTextPreallocationOptimisation");
+    return method(javaProvider_);
+  }
+
   bool enableUIConsistency() override {
     static const auto method =
         getReactNativeFeatureFlagsProviderJavaClass()->getMethod<jboolean()>("enableUIConsistency");
@@ -447,6 +453,11 @@ bool JReactNativeFeatureFlagsCxxInterop::enableSynchronousStateUpdates(
   return ReactNativeFeatureFlags::enableSynchronousStateUpdates();
 }
 
+bool JReactNativeFeatureFlagsCxxInterop::enableTextPreallocationOptimisation(
+    facebook::jni::alias_ref<JReactNativeFeatureFlagsCxxInterop> /*unused*/) {
+  return ReactNativeFeatureFlags::enableTextPreallocationOptimisation();
+}
+
 bool JReactNativeFeatureFlagsCxxInterop::enableUIConsistency(
     facebook::jni::alias_ref<JReactNativeFeatureFlagsCxxInterop> /*unused*/) {
   return ReactNativeFeatureFlags::enableUIConsistency();
@@ -665,6 +676,9 @@ void JReactNativeFeatureFlagsCxxInterop::registerNatives() {
       makeNativeMethod(
         "enableSynchronousStateUpdates",
         JReactNativeFeatureFlagsCxxInterop::enableSynchronousStateUpdates),
+      makeNativeMethod(
+        "enableTextPreallocationOptimisation",
+        JReactNativeFeatureFlagsCxxInterop::enableTextPreallocationOptimisation),
       makeNativeMethod(
         "enableUIConsistency",
         JReactNativeFeatureFlagsCxxInterop::enableUIConsistency),

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<<d39aa0038255aedc5613fc2e44b9ad88>>
+ * @generated SignedSource<<a46a48a0f3c1a84badde0aa5618faf84>>
  */
 
 /**
@@ -96,6 +96,9 @@ class JReactNativeFeatureFlagsCxxInterop
   static bool enableSynchronousStateUpdates(
     facebook::jni::alias_ref<JReactNativeFeatureFlagsCxxInterop>);
 
+  static bool enableTextPreallocationOptimisation(
+    facebook::jni::alias_ref<JReactNativeFeatureFlagsCxxInterop>);
+
   static bool enableUIConsistency(
     facebook::jni::alias_ref<JReactNativeFeatureFlagsCxxInterop>);
 

packages/react-native/ReactCommon/react/featureflags/ReactNativeFeatureFlags.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<<7c97c370b2f453691c153fb370bea149>>
+ * @generated SignedSource<<5df8c423af27ec25003d26a67ec1ef56>>
  */
 
 /**
@@ -109,6 +109,10 @@ bool ReactNativeFeatureFlags::enableSynchronousStateUpdates() {
   return getAccessor().enableSynchronousStateUpdates();
 }
 
+bool ReactNativeFeatureFlags::enableTextPreallocationOptimisation() {
+  return getAccessor().enableTextPreallocationOptimisation();
+}
+
 bool ReactNativeFeatureFlags::enableUIConsistency() {
   return getAccessor().enableUIConsistency();
 }

packages/react-native/ReactCommon/react/featureflags/ReactNativeFeatureFlags.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<<c3f43e92b0710e4a68bb76d874b3058d>>
+ * @generated SignedSource<<631e0b3e36325d36803b7e6fbefe2644>>
  */
 
 /**
@@ -147,6 +147,11 @@ class ReactNativeFeatureFlags {
    */
   RN_EXPORT static bool enableSynchronousStateUpdates();
 
+  /**
+   * Text preallocation optimisation where unnecessary work is removed.
+   */
+  RN_EXPORT static bool enableTextPreallocationOptimisation();
+
   /**
    * Ensures that JavaScript always has a consistent view of the state of the UI (e.g.: commits done in other threads are not immediately propagated to JS during its execution).
    */