[Android] Cache GPU resources using HardwareBuffer's id as key

impeller/renderer/backend/vulkan/context_vk.cc

@@ -156,7 +156,7 @@ void ContextVK::Setup(Settings settings) {
   // 1. The user has explicitly enabled it.
   // 2. We are in a combination of debug mode, and running on Android.
   // (It's possible 2 is overly conservative and we can simplify this)
-  auto enable_validation = settings.enable_validation;
+  auto enable_validation = false;  // settings.enable_validation;
 
 #if defined(FML_OS_ANDROID) && !defined(NDEBUG)
   enable_validation = true;

shell/platform/android/image_external_texture_vk.cc

@@ -1,5 +1,6 @@
 
 #include "flutter/shell/platform/android/image_external_texture_vk.h"
+#include <cstdint>
 
 #include "flutter/impeller/core/formats.h"
 #include "flutter/impeller/core/texture_descriptor.h"
@@ -31,6 +32,50 @@ void ImageExternalTextureVK::Attach(PaintContext& context) {
 
 void ImageExternalTextureVK::Detach() {}
 
+sk_sp<flutter::DlImage> ImageExternalTextureVK::FindImage(uint64_t key) {
+  for (auto i = 0u; i < kImageReaderSwapchainSize; i++) {
+    if (images_[i].first == key) {
+      UpdateKey(key);
+      return images_[i].second;
+    }
+  }
+  return nullptr;
+}
+
+void ImageExternalTextureVK::UpdateKey(uint64_t key) {
+  if (keys_[0] == key) {
+    return;
+  }
+  auto i = 1u;
+  for (; i < kImageReaderSwapchainSize; i++) {
+    if (keys_[i] == key) {
+      break;
+    }
+  }
+  for (auto j = i; j > 0; j--) {
+    keys_[j] = keys_[j - 1];
+  }
+  keys_[0] = key;
+}
+
+void ImageExternalTextureVK::AddImage(sk_sp<flutter::DlImage> image,
+                                      uint64_t key) {
+  uint64_t lru_key = keys_[2];
+  bool updated_image = false;
+  for (auto i = 0u; i < kImageReaderSwapchainSize; i++) {
+    if (images_[i].first == lru_key) {
+      updated_image = true;
+      images_[i] = std::make_pair(key, image);
+      break;
+    }
+  }
+  if (!updated_image) {
+    keys_[0] = key;
+    images_[0] = std::make_pair(key, image);
+  }
+  UpdateKey(key);
+}
+
 void ImageExternalTextureVK::ProcessFrame(PaintContext& context,
                                           const SkRect& bounds) {
   JavaLocalRef image = AcquireLatestImage();
@@ -45,6 +90,14 @@ void ImageExternalTextureVK::ProcessFrame(PaintContext& context,
   AHardwareBuffer_Desc hb_desc = {};
   flutter::NDKHelpers::AHardwareBuffer_describe(latest_hardware_buffer,
                                                 &hb_desc);
+  uint64_t key;
+  flutter::NDKHelpers::AHardwareBuffer_getId(latest_hardware_buffer, &key);
+
+  auto existing_image = FindImage(key);
+  if (existing_image != nullptr) {
+    dl_image_ = existing_image;
+    return;
+  }
 
   impeller::TextureDescriptor desc;
   desc.storage_mode = impeller::StorageMode::kDevicePrivate;
@@ -88,6 +141,7 @@ void ImageExternalTextureVK::ProcessFrame(PaintContext& context,
   }
 
   dl_image_ = impeller::DlImageImpeller::Make(texture);
+  AddImage(dl_image_, key);
   CloseHardwareBuffer(hardware_buffer);
   // IMPORTANT: We only close the old image after texture stops referencing
   // it.

shell/platform/android/image_external_texture_vk.h

@@ -5,6 +5,9 @@
 #ifndef FLUTTER_SHELL_PLATFORM_ANDROID_IMAGE_EXTERNAL_TEXTURE_VK_H_
 #define FLUTTER_SHELL_PLATFORM_ANDROID_IMAGE_EXTERNAL_TEXTURE_VK_H_
 
+#include <cstdint>
+#include <unordered_map>
+#include <utility>
 #include "flutter/shell/platform/android/image_external_texture.h"
 
 #include "flutter/impeller/renderer/backend/vulkan/android_hardware_buffer_texture_source_vk.h"
@@ -14,6 +17,8 @@
 
 namespace flutter {
 
+static constexpr size_t kImageReaderSwapchainSize = 3u;
+
 class ImageExternalTextureVK : public ImageExternalTexture {
  public:
   ImageExternalTextureVK(
@@ -30,9 +35,21 @@ class ImageExternalTextureVK : public ImageExternalTexture {
   void ProcessFrame(PaintContext& context, const SkRect& bounds) override;
   void Detach() override;
 
+  sk_sp<flutter::DlImage> FindImage(uint64_t key);
+
+  void UpdateKey(uint64_t key);
+
+  void AddImage(sk_sp<flutter::DlImage> image, uint64_t key);
+
   const std::shared_ptr<impeller::ContextVK> impeller_context_;
 
   fml::jni::ScopedJavaGlobalRef<jobject> android_image_;
+
+  std::array<std::pair<uint64_t, sk_sp<flutter::DlImage>>,
+             kImageReaderSwapchainSize>
+      images_ = {std::make_pair(0, nullptr), std::make_pair(0, nullptr),
+                 std::make_pair(0, nullptr)};
+  std::array<uint64_t, kImageReaderSwapchainSize> keys_ = {0, 0, 0};
 };
 
 }  // namespace flutter

shell/platform/android/ndk_helpers.cc

@@ -22,6 +22,9 @@ typedef void (*fp_AHardwareBuffer_acquire)(AHardwareBuffer* buffer);
 typedef void (*fp_AHardwareBuffer_release)(AHardwareBuffer* buffer);
 typedef void (*fp_AHardwareBuffer_describe)(AHardwareBuffer* buffer,
                                             AHardwareBuffer_Desc* desc);
+typedef void (*fp_AHardwareBuffer_getId)(AHardwareBuffer* buffer,
+                                         uint64_t* outId);
+
 typedef EGLClientBuffer (*fp_eglGetNativeClientBufferANDROID)(
     AHardwareBuffer* buffer);
 
@@ -32,6 +35,8 @@ void (*_AHardwareBuffer_acquire)(AHardwareBuffer* buffer) = nullptr;
 void (*_AHardwareBuffer_release)(AHardwareBuffer* buffer) = nullptr;
 void (*_AHardwareBuffer_describe)(AHardwareBuffer* buffer,
                                   AHardwareBuffer_Desc* desc) = nullptr;
+void (*_AHardwareBuffer_getId)(AHardwareBuffer* buffer,
+                               uint64_t* outId) = nullptr;
 EGLClientBuffer (*_eglGetNativeClientBufferANDROID)(AHardwareBuffer* buffer) =
     nullptr;
 
@@ -61,6 +66,10 @@ void InitOnceCallback() {
                                  ->ResolveFunction<fp_AHardwareBuffer_release>(
                                      "AHardwareBuffer_release")
                                  .value_or(nullptr);
+  _AHardwareBuffer_getId =
+      android
+          ->ResolveFunction<fp_AHardwareBuffer_getId>("AHardwareBuffer_getId")
+          .value_or(nullptr);
   _AHardwareBuffer_describe =
       android
           ->ResolveFunction<fp_AHardwareBuffer_describe>(
@@ -107,6 +116,13 @@ void NDKHelpers::AHardwareBuffer_describe(AHardwareBuffer* buffer,
   _AHardwareBuffer_describe(buffer, desc);
 }
 
+void NDKHelpers::AHardwareBuffer_getId(AHardwareBuffer* buffer,
+                                       uint64_t* outId) {
+  NDKHelpers::Init();
+  FML_CHECK(_AHardwareBuffer_getId != nullptr);
+  _AHardwareBuffer_getId(buffer, outId);
+}
+
 EGLClientBuffer NDKHelpers::eglGetNativeClientBufferANDROID(
     AHardwareBuffer* buffer) {
   NDKHelpers::Init();

shell/platform/android/ndk_helpers.h

@@ -27,6 +27,7 @@ class NDKHelpers {
   static void AHardwareBuffer_release(AHardwareBuffer* buffer);
   static void AHardwareBuffer_describe(AHardwareBuffer* buffer,
                                        AHardwareBuffer_Desc* desc);
+  static void AHardwareBuffer_getId(AHardwareBuffer* buffer, uint64_t* outId);
   static EGLClientBuffer eglGetNativeClientBufferANDROID(
       AHardwareBuffer* buffer);