PlatformColor caching & invalidation (#54076)

Summary:
Pull Request resolved: https://github.com/facebook/react-native/pull/54076

Changelog: [Internal]
Add PlatformColor caching so we do not need to make as many JNI calls which helps with perf.

Reviewed By: javache

Differential Revision: D83050864

fbshipit-source-id: 56a53a5facccdbbb3ff18a66df9e07d794bb074c

packages/react-native/ReactAndroid/api/ReactAndroid.api

@@ -2478,6 +2478,7 @@ public final class com/facebook/react/modules/appearance/AppearanceModule : com/
 	public fun addListener (Ljava/lang/String;)V
 	public final fun emitAppearanceChanged (Ljava/lang/String;)V
 	public fun getColorScheme ()Ljava/lang/String;
+	public final fun invalidatePlatformColorCache ()V
 	public final fun onConfigurationChanged (Landroid/content/Context;)V
 	public fun removeListeners (D)V
 	public fun setColorScheme (Ljava/lang/String;)V

packages/react-native/ReactAndroid/src/main/java/com/facebook/react/modules/appearance/AppearanceModule.kt

@@ -10,6 +10,7 @@ package com.facebook.react.modules.appearance
 import android.content.Context
 import androidx.appcompat.app.AppCompatDelegate
 import com.facebook.fbreact.specs.NativeAppearanceSpec
+import com.facebook.jni.annotations.DoNotStrip
 import com.facebook.react.bridge.ReactApplicationContext
 import com.facebook.react.bridge.UiThreadUtil
 import com.facebook.react.bridge.buildReadableMap
@@ -84,12 +85,23 @@ constructor(
   /** Sends an event to the JS instance that the preferred color scheme has changed. */
   public fun emitAppearanceChanged(colorScheme: String) {
     val appearancePreferences = buildReadableMap { put("colorScheme", colorScheme) }
+
     val reactApplicationContext = getReactApplicationContextIfActiveOrWarn()
     reactApplicationContext?.emitDeviceEvent(APPEARANCE_CHANGED_EVENT_NAME, appearancePreferences)
+
+    // Invalidate platform color cache on native side
+    invalidatePlatformColorCache()
+  }
+
+  public fun invalidatePlatformColorCache() {
+    // call into static invalidatePlatformColorCache?.run() method
+    Companion.invalidatePlatformColorCache?.run()
   }
 
   public companion object {
     public const val NAME: String = NativeAppearanceSpec.NAME
     private const val APPEARANCE_CHANGED_EVENT_NAME = "appearanceChanged"
+
+    @DoNotStrip private var invalidatePlatformColorCache: Runnable? = null
   }
 }

packages/react-native/ReactCommon/react/renderer/graphics/platform/android/react/renderer/graphics/PlatformColorParser.h

@@ -7,50 +7,86 @@
 
 #pragma once
 
+#include "configurePlatformColorCacheInvalidationHook.h"
+
 #include <fbjni/fbjni.h>
-#include <react/debug/react_native_expect.h>
+#include <folly/container/EvictingCacheMap.h>
 #include <react/renderer/core/RawValue.h>
 #include <react/renderer/graphics/Color.h>
 #include <react/renderer/graphics/fromRawValueShared.h>
 #include <react/utils/ContextContainer.h>
+#include <functional>
+#include <mutex>
+#include <string>
 #include <unordered_map>
+#include <vector>
 
 namespace facebook::react {
 
+inline size_t hashGetColourArguments(
+    int32_t surfaceId,
+    const std::vector<std::string>& resourcePaths) {
+  size_t seed = std::hash<int32_t>{}(surfaceId);
+  for (const auto& path : resourcePaths) {
+    seed ^=
+        std::hash<std::string>{}(path) + 0x9e3779b9 + (seed << 6) + (seed >> 2);
+  }
+  return seed;
+}
+
 inline SharedColor parsePlatformColor(
     const ContextContainer& contextContainer,
     int32_t surfaceId,
     const RawValue& value) {
-  ColorComponents colorComponents = {0, 0, 0, 0};
-
+  Color color = 0;
   if (value.hasType<
           std::unordered_map<std::string, std::vector<std::string>>>()) {
-    const auto& fabricUIManager =
-        contextContainer.at<jni::global_ref<jobject>>("FabricUIManager");
-    static auto getColorFromJava =
-        fabricUIManager->getClass()
-            ->getMethod<jint(jint, jni::JArrayClass<jni::JString>)>("getColor");
-
     auto map = (std::unordered_map<std::string, std::vector<std::string>>)value;
     auto& resourcePaths = map["resource_paths"];
 
-    auto javaResourcePaths =
-        jni::JArrayClass<jni::JString>::newArray(resourcePaths.size());
-    for (int i = 0; i < resourcePaths.size(); i++) {
-      javaResourcePaths->setElement(i, *jni::make_jstring(resourcePaths[i]));
-    }
-    auto color =
-        getColorFromJava(fabricUIManager, surfaceId, *javaResourcePaths);
+    // JNI calls are time consuming. Let's cache results here to avoid
+    // unnecessary calls.
+    static std::mutex getColorCacheMutex;
+    static folly::EvictingCacheMap<size_t, Color> getColorCache(64);
 
-    auto argb = (int64_t)color;
-    auto ratio = 255.f;
-    colorComponents.alpha = ((argb >> 24) & 0xFF) / ratio;
-    colorComponents.red = ((argb >> 16) & 0xFF) / ratio;
-    colorComponents.green = ((argb >> 8) & 0xFF) / ratio;
-    colorComponents.blue = (argb & 0xFF) / ratio;
+    // Listen for appearance changes, which should invalidate the cache
+    static std::once_flag setupCacheInvalidation;
+    std::call_once(
+        setupCacheInvalidation,
+        configurePlatformColorCacheInvalidationHook,
+        [&] {
+          std::scoped_lock lock(getColorCacheMutex);
+          getColorCache.clear();
+        });
+
+    auto hash = hashGetColourArguments(surfaceId, resourcePaths);
+    {
+      std::scoped_lock lock(getColorCacheMutex);
+      auto iterator = getColorCache.find(hash);
+      if (iterator != getColorCache.end()) {
+        color = iterator->second;
+      } else {
+        const auto& fabricUIManager =
+            contextContainer.at<jni::global_ref<jobject>>("FabricUIManager");
+        static auto getColorFromJava =
+            fabricUIManager->getClass()
+                ->getMethod<jint(jint, jni::JArrayClass<jni::JString>)>(
+                    "getColor");
+        auto javaResourcePaths =
+            jni::JArrayClass<jni::JString>::newArray(resourcePaths.size());
+
+        for (int i = 0; i < resourcePaths.size(); i++) {
+          javaResourcePaths->setElement(
+              i, *jni::make_jstring(resourcePaths[i]));
+        }
+        color =
+            getColorFromJava(fabricUIManager, surfaceId, *javaResourcePaths);
+        getColorCache.set(hash, color);
+      }
+    }
   }
 
-  return {colorFromComponents(colorComponents)};
+  return color;
 }
 
 inline void fromRawValue(

packages/react-native/ReactCommon/react/renderer/graphics/platform/android/react/renderer/graphics/configurePlatformColorCacheInvalidationHook.cpp

@@ -0,0 +1,27 @@
+/*
+ * 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 "configurePlatformColorCacheInvalidationHook.h"
+
+#include <fbjni/NativeRunnable.h>
+#include <fbjni/fbjni.h>
+
+namespace facebook::react {
+void configurePlatformColorCacheInvalidationHook(std::function<void()>&& hook) {
+  auto appearanceModuleClass = jni::findClassLocal(
+      "com/facebook/react/modules/appearance/AppearanceModule");
+  if (appearanceModuleClass) {
+    auto callbackField =
+        appearanceModuleClass->getStaticField<jni::JRunnable::javaobject>(
+            "invalidatePlatformColorCache");
+    jni::local_ref<jni::JRunnable> invalidationCallback =
+        jni::JNativeRunnable::newObjectCxxArgs(std::move(hook));
+    appearanceModuleClass->setStaticFieldValue(
+        callbackField, invalidationCallback.get());
+  }
+}
+} // namespace facebook::react

packages/react-native/ReactCommon/react/renderer/graphics/platform/android/react/renderer/graphics/configurePlatformColorCacheInvalidationHook.h

@@ -0,0 +1,12 @@
+/*
+ * 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 <functional>
+
+namespace facebook::react {
+void configurePlatformColorCacheInvalidationHook(std::function<void()>&& hook);
+} // namespace facebook::react