Merge pull request #13386 from iwubcode/resource_manager_system

VideoCommon: add resource manager, tracks resources to load assets in optimal way and manage memory

.gitmodules

@@ -84,6 +84,9 @@
 [submodule "Externals/Vulkan-Headers"]
 	path = Externals/Vulkan-Headers
 	url = https://github.com/KhronosGroup/Vulkan-Headers.git
+[submodule "Externals/watcher/watcher"]
+	path = Externals/watcher/watcher
+	url = https://github.com/e-dant/watcher.git
 [submodule "Externals/SFML/SFML"]
 	path = Externals/SFML/SFML
 	url = https://github.com/SFML/SFML.git

CMakeLists.txt

@@ -784,6 +784,8 @@ if (USE_RETRO_ACHIEVEMENTS)
 	add_subdirectory(Externals/rcheevos)
 endif()
 
+add_subdirectory(Externals/watcher)
+
 ########################################
 # Pre-build events: Define configuration variables and write SCM info header
 #

Externals/watcher/CMakeLists.txt

@@ -0,0 +1,4 @@
+add_library(watcher INTERFACE IMPORTED GLOBAL)
+set_target_properties(watcher PROPERTIES
+	INTERFACE_INCLUDE_DIRECTORIES ${CMAKE_CURRENT_LIST_DIR}/watcher/include
+)

Source/Core/Common/CMakeLists.txt

@@ -64,6 +64,8 @@ add_library(common
   FatFsUtil.h
   FileSearch.cpp
   FileSearch.h
+  FilesystemWatcher.cpp
+  FilesystemWatcher.h
   FileUtil.cpp
   FileUtil.h
   FixedSizeQueue.h
@@ -184,6 +186,7 @@ PRIVATE
   FatFs
   Iconv::Iconv
   spng::spng
+  watcher
   ${VTUNE_LIBRARIES}
 )
 

Source/Core/Common/FilesystemWatcher.cpp

@@ -0,0 +1,67 @@
+// Copyright 2025 Dolphin Emulator Project
+// SPDX-License-Identifier: GPL-2.0-or-later
+
+#include "Common/FilesystemWatcher.h"
+
+#include <wtr/watcher.hpp>
+
+#include "Common/Logging/Log.h"
+#include "Common/StringUtil.h"
+
+namespace Common
+{
+FilesystemWatcher::FilesystemWatcher() = default;
+FilesystemWatcher::~FilesystemWatcher() = default;
+
+void FilesystemWatcher::Watch(const std::string& path)
+{
+  const auto [iter, inserted] = m_watched_paths.try_emplace(path, nullptr);
+  if (inserted)
+  {
+    iter->second = std::make_unique<wtr::watch>(path, [this](wtr::event e) {
+      const auto watched_path = PathToString(e.path_name);
+      if (e.path_type == wtr::event::path_type::watcher)
+      {
+        if (watched_path.starts_with('e'))
+          ERROR_LOG_FMT(COMMON, "Filesystem watcher: '{}'", watched_path);
+        else if (watched_path.starts_with('w'))
+          WARN_LOG_FMT(COMMON, "Filesystem watcher: '{}'", watched_path);
+        return;
+      }
+
+      if (e.effect_type == wtr::event::effect_type::create)
+      {
+        const auto path = WithUnifiedPathSeparators(watched_path);
+        PathAdded(path);
+      }
+      else if (e.effect_type == wtr::event::effect_type::modify)
+      {
+        const auto path = WithUnifiedPathSeparators(watched_path);
+        PathModified(path);
+      }
+      else if (e.effect_type == wtr::event::effect_type::rename)
+      {
+        if (!e.associated)
+        {
+          WARN_LOG_FMT(COMMON, "Rename on path '{}' seen without association!", watched_path);
+          return;
+        }
+
+        const auto old_path = WithUnifiedPathSeparators(watched_path);
+        const auto new_path = WithUnifiedPathSeparators(PathToString(e.associated->path_name));
+        PathRenamed(old_path, new_path);
+      }
+      else if (e.effect_type == wtr::event::effect_type::destroy)
+      {
+        const auto path = WithUnifiedPathSeparators(watched_path);
+        PathDeleted(path);
+      }
+    });
+  }
+}
+
+void FilesystemWatcher::Unwatch(const std::string& path)
+{
+  m_watched_paths.erase(path);
+}
+}  // namespace Common

Source/Core/Common/FilesystemWatcher.h

@@ -0,0 +1,47 @@
+// Copyright 2025 Dolphin Emulator Project
+// SPDX-License-Identifier: GPL-2.0-or-later
+
+#pragma once
+
+#include <map>
+#include <memory>
+#include <string>
+#include <string_view>
+
+namespace wtr
+{
+inline namespace watcher
+{
+class watch;
+}
+}  // namespace wtr
+
+namespace Common
+{
+// A class that can watch a path and receive callbacks
+// when files or directories underneath that path receive events
+class FilesystemWatcher
+{
+public:
+  FilesystemWatcher();
+  virtual ~FilesystemWatcher();
+
+  void Watch(const std::string& path);
+  void Unwatch(const std::string& path);
+
+private:
+  // A new file or folder was added to one of the watched paths
+  virtual void PathAdded(std::string_view path) {}
+
+  // A file or folder was modified in one of the watched paths
+  virtual void PathModified(std::string_view path) {}
+
+  // A file or folder was renamed in one of the watched paths
+  virtual void PathRenamed(std::string_view old_path, std::string_view new_path) {}
+
+  // A file or folder was deleted in one of the watched paths
+  virtual void PathDeleted(std::string_view path) {}
+
+  std::map<std::string, std::unique_ptr<wtr::watch>> m_watched_paths;
+};
+}  // namespace Common

Source/Core/Core/Core.cpp

@@ -82,7 +82,6 @@
 #include "InputCommon/ControllerInterface/ControllerInterface.h"
 #include "InputCommon/GCAdapter.h"
 
-#include "VideoCommon/Assets/CustomAssetLoader.h"
 #include "VideoCommon/AsyncRequests.h"
 #include "VideoCommon/Fifo.h"
 #include "VideoCommon/FrameDumper.h"
@@ -528,9 +527,6 @@ static void EmuThread(Core::System& system, std::unique_ptr<BootParameters> boot
 
   FreeLook::LoadInputConfig();
 
-  system.GetCustomAssetLoader().Init();
-  Common::ScopeGuard asset_loader_guard([&system] { system.GetCustomAssetLoader().Shutdown(); });
-
   system.GetMovie().Init(*boot);
   Common::ScopeGuard movie_guard([&system] { system.GetMovie().Shutdown(); });
 

Source/Core/Core/System.cpp

@@ -33,7 +33,7 @@
 #include "IOS/USB/Emulated/Infinity.h"
 #include "IOS/USB/Emulated/Skylanders/Skylander.h"
 #include "IOS/USB/USBScanner.h"
-#include "VideoCommon/Assets/CustomAssetLoader.h"
+#include "VideoCommon/Assets/CustomResourceManager.h"
 #include "VideoCommon/CommandProcessor.h"
 #include "VideoCommon/Fifo.h"
 #include "VideoCommon/GeometryShaderManager.h"
@@ -96,7 +96,7 @@ struct System::Impl
   VideoInterface::VideoInterfaceManager m_video_interface;
   Interpreter m_interpreter;
   JitInterface m_jit_interface;
-  VideoCommon::CustomAssetLoader m_custom_asset_loader;
+  VideoCommon::CustomResourceManager m_custom_resource_manager;
   FifoPlayer m_fifo_player;
   FifoRecorder m_fifo_recorder;
   Movie::MovieManager m_movie;
@@ -335,8 +335,8 @@ VideoInterface::VideoInterfaceManager& System::GetVideoInterface() const
   return m_impl->m_video_interface;
 }
 
-VideoCommon::CustomAssetLoader& System::GetCustomAssetLoader() const
+VideoCommon::CustomResourceManager& System::GetCustomResourceManager() const
 {
-  return m_impl->m_custom_asset_loader;
+  return m_impl->m_custom_resource_manager;
 }
 }  // namespace Core

Source/Core/Core/System.h

@@ -108,8 +108,8 @@ class SystemTimersManager;
 }
 namespace VideoCommon
 {
-class CustomAssetLoader;
-}
+class CustomResourceManager;
+}  // namespace VideoCommon
 namespace VideoInterface
 {
 class VideoInterfaceManager;
@@ -197,7 +197,7 @@ public:
   VertexShaderManager& GetVertexShaderManager() const;
   XFStateManager& GetXFStateManager() const;
   VideoInterface::VideoInterfaceManager& GetVideoInterface() const;
-  VideoCommon::CustomAssetLoader& GetCustomAssetLoader() const;
+  VideoCommon::CustomResourceManager& GetCustomResourceManager() const;
 
 private:
   System();

Source/Core/DolphinLib.props

@@ -59,6 +59,7 @@
     <ClInclude Include="Common\Event.h" />
     <ClInclude Include="Common\FatFsUtil.h" />
     <ClInclude Include="Common\FileSearch.h" />
+    <ClInclude Include="Common\FilesystemWatcher.h" />
     <ClInclude Include="Common\FileUtil.h" />
     <ClInclude Include="Common\FixedSizeQueue.h" />
     <ClInclude Include="Common\Flag.h" />
@@ -669,12 +670,16 @@
     <ClInclude Include="VideoCommon\Assets\CustomAsset.h" />
     <ClInclude Include="VideoCommon\Assets\CustomAssetLibrary.h" />
     <ClInclude Include="VideoCommon\Assets\CustomAssetLoader.h" />
+    <ClInclude Include="VideoCommon\Assets\CustomResourceManager.h" />
     <ClInclude Include="VideoCommon\Assets\CustomTextureData.h" />
     <ClInclude Include="VideoCommon\Assets\DirectFilesystemAssetLibrary.h" />
     <ClInclude Include="VideoCommon\Assets\MaterialAsset.h" />
     <ClInclude Include="VideoCommon\Assets\MeshAsset.h" />
     <ClInclude Include="VideoCommon\Assets\ShaderAsset.h" />
     <ClInclude Include="VideoCommon\Assets\TextureAsset.h" />
+    <ClInclude Include="VideoCommon\Assets\TextureAssetUtils.h" />
+    <ClInclude Include="VideoCommon\Assets\Types.h" />
+    <ClInclude Include="VideoCommon\Assets\WatchableFilesystemAssetLibrary.h" />
     <ClInclude Include="VideoCommon\AsyncRequests.h" />
     <ClInclude Include="VideoCommon\AsyncShaderCompiler.h" />
     <ClInclude Include="VideoCommon\BoundingBox.h" />
@@ -814,6 +819,7 @@
     <ClCompile Include="Common\ENet.cpp" />
     <ClCompile Include="Common\FatFsUtil.cpp" />
     <ClCompile Include="Common\FileSearch.cpp" />
+    <ClCompile Include="Common\FilesystemWatcher.cpp" />
     <ClCompile Include="Common\FileUtil.cpp" />
     <ClCompile Include="Common\FloatUtils.cpp" />
     <ClCompile Include="Common\GekkoDisassembler.cpp" />
@@ -1320,14 +1326,15 @@
     <ClCompile Include="VideoCommon\AbstractStagingTexture.cpp" />
     <ClCompile Include="VideoCommon\AbstractTexture.cpp" />
     <ClCompile Include="VideoCommon\Assets\CustomAsset.cpp" />
-    <ClCompile Include="VideoCommon\Assets\CustomAssetLibrary.cpp" />
     <ClCompile Include="VideoCommon\Assets\CustomAssetLoader.cpp" />
+    <ClCompile Include="VideoCommon\Assets\CustomResourceManager.cpp" />
     <ClCompile Include="VideoCommon\Assets\CustomTextureData.cpp" />
     <ClCompile Include="VideoCommon\Assets\DirectFilesystemAssetLibrary.cpp" />
     <ClCompile Include="VideoCommon\Assets\MaterialAsset.cpp" />
     <ClCompile Include="VideoCommon\Assets\MeshAsset.cpp" />
     <ClCompile Include="VideoCommon\Assets\ShaderAsset.cpp" />
     <ClCompile Include="VideoCommon\Assets\TextureAsset.cpp" />
+    <ClCompile Include="VideoCommon\Assets\TextureAssetUtils.cpp" />
     <ClCompile Include="VideoCommon\AsyncRequests.cpp" />
     <ClCompile Include="VideoCommon\AsyncShaderCompiler.cpp" />
     <ClCompile Include="VideoCommon\BoundingBox.cpp" />

Source/Core/VideoCommon/Assets/CustomAsset.cpp

@@ -3,46 +3,54 @@
 
 #include "VideoCommon/Assets/CustomAsset.h"
 
+#include <utility>
+
 namespace VideoCommon
 {
 CustomAsset::CustomAsset(std::shared_ptr<CustomAssetLibrary> library,
-                         const CustomAssetLibrary::AssetID& asset_id)
-    : m_owning_library(std::move(library)), m_asset_id(asset_id)
+                         const CustomAssetLibrary::AssetID& asset_id, u64 asset_handle)
+    : m_owning_library(std::move(library)), m_asset_id(asset_id), m_handle(asset_handle)
 {
 }
 
-bool CustomAsset::Load()
-{
-  const auto load_information = LoadImpl(m_asset_id);
-  if (load_information.m_bytes_loaded > 0)
-  {
-    std::lock_guard lk(m_info_lock);
-    m_bytes_loaded = load_information.m_bytes_loaded;
-    m_last_loaded_time = load_information.m_load_time;
-  }
-  return load_information.m_bytes_loaded != 0;
-}
-
-CustomAssetLibrary::TimeType CustomAsset::GetLastWriteTime() const
-{
-  return m_owning_library->GetLastAssetWriteTime(m_asset_id);
-}
-
-const CustomAssetLibrary::TimeType& CustomAsset::GetLastLoadedTime() const
+std::size_t CustomAsset::Load()
 {
   std::lock_guard lk(m_info_lock);
+  // The load time needs to come from before the data is actually read.
+  // Using a time point from after the read marks the asset as more up-to-date than it actually is,
+  //  and has potential to race (and not be updated) if a change happens immediately after load.
+  const auto load_time = ClockType::now();
+
+  const auto load_information = LoadImpl(m_asset_id);
+  if (load_information.bytes_loaded > 0)
+  {
+    m_bytes_loaded = load_information.bytes_loaded;
+    m_last_loaded_time = load_time;
+    return m_bytes_loaded;
+  }
+  return 0;
+}
+
+std::size_t CustomAsset::Unload()
+{
+  std::lock_guard lk(m_info_lock);
+  UnloadImpl();
+  return std::exchange(m_bytes_loaded, 0);
+}
+
+CustomAsset::TimeType CustomAsset::GetLastLoadedTime() const
+{
   return m_last_loaded_time;
 }
 
+std::size_t CustomAsset::GetHandle() const
+{
+  return m_handle;
+}
+
 const CustomAssetLibrary::AssetID& CustomAsset::GetAssetId() const
 {
   return m_asset_id;
 }
 
-std::size_t CustomAsset::GetByteSizeInMemory() const
-{
-  std::lock_guard lk(m_info_lock);
-  return m_bytes_loaded;
-}
-
 }  // namespace VideoCommon

Source/Core/VideoCommon/Assets/CustomAsset.h

@@ -6,9 +6,9 @@
 #include "Common/CommonTypes.h"
 #include "VideoCommon/Assets/CustomAssetLibrary.h"
 
+#include <atomic>
 #include <memory>
 #include <mutex>
-#include <optional>
 
 namespace VideoCommon
 {
@@ -17,42 +17,47 @@ namespace VideoCommon
 class CustomAsset
 {
 public:
+  using ClockType = std::chrono::steady_clock;
+  using TimeType = ClockType::time_point;
+
   CustomAsset(std::shared_ptr<CustomAssetLibrary> library,
-              const CustomAssetLibrary::AssetID& asset_id);
+              const CustomAssetLibrary::AssetID& asset_id, u64 session_id);
   virtual ~CustomAsset() = default;
   CustomAsset(const CustomAsset&) = delete;
   CustomAsset(CustomAsset&&) = delete;
   CustomAsset& operator=(const CustomAsset&) = delete;
   CustomAsset& operator=(CustomAsset&&) = delete;
 
-  // Loads the asset from the library returning a pass/fail result
-  bool Load();
+  // Loads the asset from the library returning the number of bytes loaded
+  std::size_t Load();
 
-  // Queries the last time the asset was modified or standard epoch time
-  // if the asset hasn't been modified yet
-  // Note: not thread safe, expected to be called by the loader
-  CustomAssetLibrary::TimeType GetLastWriteTime() const;
+  // Unloads the asset data, resets the bytes loaded and
+  // returns the number of bytes unloaded
+  std::size_t Unload();
 
   // Returns the time that the data was last loaded
-  const CustomAssetLibrary::TimeType& GetLastLoadedTime() const;
+  TimeType GetLastLoadedTime() const;
 
   // Returns an id that uniquely identifies this asset
   const CustomAssetLibrary::AssetID& GetAssetId() const;
 
-  // A rough estimate of how much space this asset
-  // will take in memroy
-  std::size_t GetByteSizeInMemory() const;
+  // Returns an id that is unique to this game session
+  // This is a faster form to hash and can be used
+  // as an index
+  std::size_t GetHandle() const;
 
 protected:
   const std::shared_ptr<CustomAssetLibrary> m_owning_library;
 
 private:
   virtual CustomAssetLibrary::LoadInfo LoadImpl(const CustomAssetLibrary::AssetID& asset_id) = 0;
+  virtual void UnloadImpl() = 0;
   CustomAssetLibrary::AssetID m_asset_id;
+  std::size_t m_handle;
 
   mutable std::mutex m_info_lock;
   std::size_t m_bytes_loaded = 0;
-  CustomAssetLibrary::TimeType m_last_loaded_time = {};
+  std::atomic<TimeType> m_last_loaded_time = {};
 };
 
 // An abstract class that is expected to
@@ -83,6 +88,14 @@ protected:
   bool m_loaded = false;
   mutable std::mutex m_data_lock;
   std::shared_ptr<UnderlyingType> m_data;
+
+private:
+  void UnloadImpl() override
+  {
+    std::lock_guard lk(m_data_lock);
+    m_loaded = false;
+    m_data.reset();
+  }
 };
 
 // A helper struct that contains
@@ -96,7 +109,7 @@ template <typename AssetType>
 struct CachedAsset
 {
   std::shared_ptr<AssetType> m_asset;
-  VideoCommon::CustomAssetLibrary::TimeType m_cached_write_time;
+  CustomAsset::TimeType m_cached_write_time;
 };
 
 }  // namespace VideoCommon

Source/Core/VideoCommon/Assets/CustomAssetLibrary.cpp

@@ -1,85 +0,0 @@
-// Copyright 2023 Dolphin Emulator Project
-// SPDX-License-Identifier: GPL-2.0-or-later
-
-#include "VideoCommon/Assets/CustomAssetLibrary.h"
-
-#include <algorithm>
-
-#include "Common/Logging/Log.h"
-#include "VideoCommon/Assets/TextureAsset.h"
-
-namespace VideoCommon
-{
-CustomAssetLibrary::LoadInfo CustomAssetLibrary::LoadGameTexture(const AssetID& asset_id,
-                                                                 TextureData* data)
-{
-  const auto load_info = LoadTexture(asset_id, data);
-  if (load_info.m_bytes_loaded == 0)
-    return {};
-
-  if (data->m_type != TextureData::Type::Type_Texture2D)
-  {
-    ERROR_LOG_FMT(
-        VIDEO,
-        "Custom asset '{}' is not a valid game texture, it is expected to be a 2d texture "
-        "but was a '{}'.",
-        asset_id, data->m_type);
-    return {};
-  }
-
-  // Note: 'LoadTexture()' ensures we have a level loaded
-  for (std::size_t slice_index = 0; slice_index < data->m_texture.m_slices.size(); slice_index++)
-  {
-    auto& slice = data->m_texture.m_slices[slice_index];
-    const auto& first_mip = slice.m_levels[0];
-
-    // Verify that each mip level is the correct size (divide by 2 each time).
-    u32 current_mip_width = first_mip.width;
-    u32 current_mip_height = first_mip.height;
-    for (u32 mip_level = 1; mip_level < static_cast<u32>(slice.m_levels.size()); mip_level++)
-    {
-      if (current_mip_width != 1 || current_mip_height != 1)
-      {
-        current_mip_width = std::max(current_mip_width / 2, 1u);
-        current_mip_height = std::max(current_mip_height / 2, 1u);
-
-        const VideoCommon::CustomTextureData::ArraySlice::Level& level = slice.m_levels[mip_level];
-        if (current_mip_width == level.width && current_mip_height == level.height)
-          continue;
-
-        ERROR_LOG_FMT(VIDEO,
-                      "Invalid custom game texture size {}x{} for texture asset {}. Slice {} with "
-                      "mipmap level {} "
-                      "must be {}x{}.",
-                      level.width, level.height, asset_id, slice_index, mip_level,
-                      current_mip_width, current_mip_height);
-      }
-      else
-      {
-        // It is invalid to have more than a single 1x1 mipmap.
-        ERROR_LOG_FMT(
-            VIDEO,
-            "Custom game texture {} has too many 1x1 mipmaps for slice {}. Skipping extra levels.",
-            asset_id, slice_index);
-      }
-
-      // Drop this mip level and any others after it.
-      while (slice.m_levels.size() > mip_level)
-        slice.m_levels.pop_back();
-    }
-
-    // All levels have to have the same format.
-    if (std::ranges::any_of(slice.m_levels,
-                            [&first_mip](const auto& l) { return l.format != first_mip.format; }))
-    {
-      ERROR_LOG_FMT(
-          VIDEO, "Custom game texture {} has inconsistent formats across mip levels for slice {}.",
-          asset_id, slice_index);
-
-      return {};
-    }
-  }
-
-  return load_info;
-}
-}  // namespace VideoCommon

Source/Core/VideoCommon/Assets/CustomAssetLibrary.h

@@ -10,10 +10,11 @@
 
 namespace VideoCommon
 {
+class CustomTextureData;
 struct MaterialData;
 struct MeshData;
 struct PixelShaderData;
-struct TextureData;
+struct TextureAndSamplerData;
 
 // This class provides functionality to load
 // specific data (like textures).  Where this data
@@ -21,28 +22,21 @@ struct TextureData;
 class CustomAssetLibrary
 {
 public:
-  using TimeType = std::chrono::system_clock::time_point;
-
   // The AssetID is a unique identifier for a particular asset
   using AssetID = std::string;
 
   struct LoadInfo
   {
-    std::size_t m_bytes_loaded = 0;
-    TimeType m_load_time = {};
+    std::size_t bytes_loaded = 0;
   };
 
   virtual ~CustomAssetLibrary() = default;
 
+  // Loads a texture with a sampler and type, if there are no levels, bytes loaded will be empty
+  virtual LoadInfo LoadTexture(const AssetID& asset_id, TextureAndSamplerData* data) = 0;
+
   // Loads a texture, if there are no levels, bytes loaded will be empty
-  virtual LoadInfo LoadTexture(const AssetID& asset_id, TextureData* data) = 0;
-
-  // Gets the last write time for a given asset id
-  virtual TimeType GetLastAssetWriteTime(const AssetID& asset_id) const = 0;
-
-  // Loads a texture as a game texture, providing additional checks like confirming
-  // each mip level size is correct and that the format is consistent across the data
-  LoadInfo LoadGameTexture(const AssetID& asset_id, TextureData* data);
+  virtual LoadInfo LoadTexture(const AssetID& asset_id, CustomTextureData* data) = 0;
 
   // Loads a pixel shader
   virtual LoadInfo LoadPixelShader(const AssetID& asset_id, PixelShaderData* data) = 0;

Source/Core/VideoCommon/Assets/CustomAssetLoader.cpp

@@ -1,108 +1,157 @@
-// Copyright 2023 Dolphin Emulator Project
+// Copyright 2025 Dolphin Emulator Project
 // SPDX-License-Identifier: GPL-2.0-or-later
 
 #include "VideoCommon/Assets/CustomAssetLoader.h"
 
-#include "Common/MemoryUtil.h"
-#include "VideoCommon/Assets/CustomAssetLibrary.h"
+#include <fmt/format.h>
+
+#include "Common/Logging/Log.h"
+#include "Common/Thread.h"
+
+#include "UICommon/UICommon.h"
 
 namespace VideoCommon
 {
-void CustomAssetLoader::Init()
+void CustomAssetLoader::Initialize()
 {
-  m_asset_monitor_thread_shutdown.Clear();
-
-  const size_t sys_mem = Common::MemPhysical();
-  const size_t recommended_min_mem = 2 * size_t(1024 * 1024 * 1024);
-  // keep 2GB memory for system stability if system RAM is 4GB+ - use half of memory in other cases
-  m_max_memory_available =
-      (sys_mem / 2 < recommended_min_mem) ? (sys_mem / 2) : (sys_mem - recommended_min_mem);
-
-  m_asset_monitor_thread = std::thread([this]() {
-    Common::SetCurrentThreadName("Asset monitor");
-    while (true)
-    {
-      if (m_asset_monitor_thread_shutdown.IsSet())
-      {
-        break;
-      }
-
-      std::this_thread::sleep_for(TIME_BETWEEN_ASSET_MONITOR_CHECKS);
-
-      std::lock_guard lk(m_asset_load_lock);
-      for (auto& [asset_id, asset_to_monitor] : m_assets_to_monitor)
-      {
-        if (auto ptr = asset_to_monitor.lock())
-        {
-          const auto write_time = ptr->GetLastWriteTime();
-          if (write_time > ptr->GetLastLoadedTime())
-          {
-            (void)ptr->Load();
-          }
-        }
-      }
-    }
-  });
-
-  m_asset_load_thread.Reset("Custom Asset Loader", [this](std::weak_ptr<CustomAsset> asset) {
-    if (auto ptr = asset.lock())
-    {
-      if (m_memory_exceeded)
-        return;
-
-      if (ptr->Load())
-      {
-        std::lock_guard lk(m_asset_load_lock);
-        const std::size_t asset_memory_size = ptr->GetByteSizeInMemory();
-        m_total_bytes_loaded += asset_memory_size;
-        m_assets_to_monitor.try_emplace(ptr->GetAssetId(), ptr);
-        if (m_total_bytes_loaded > m_max_memory_available)
-        {
-          ERROR_LOG_FMT(VIDEO,
-                        "Asset memory exceeded with asset '{}', future assets won't load until "
-                        "memory is available.",
-                        ptr->GetAssetId());
-          m_memory_exceeded = true;
-        }
-      }
-    }
-  });
+  ResizeWorkerThreads(2);
 }
 
 void CustomAssetLoader::Shutdown()
 {
-  m_asset_load_thread.StopAndCancel();
-
-  m_asset_monitor_thread_shutdown.Set();
-  m_asset_monitor_thread.join();
-  m_assets_to_monitor.clear();
-  m_total_bytes_loaded = 0;
+  Reset(false);
 }
 
-std::shared_ptr<GameTextureAsset>
-CustomAssetLoader::LoadGameTexture(const CustomAssetLibrary::AssetID& asset_id,
-                                   std::shared_ptr<CustomAssetLibrary> library)
+bool CustomAssetLoader::StartWorkerThreads(u32 num_worker_threads)
 {
-  return LoadOrCreateAsset<GameTextureAsset>(asset_id, m_game_textures, std::move(library));
+  for (u32 i = 0; i < num_worker_threads; i++)
+  {
+    m_worker_threads.emplace_back(&CustomAssetLoader::WorkerThreadRun, this, i);
+  }
+
+  return HasWorkerThreads();
 }
 
-std::shared_ptr<PixelShaderAsset>
-CustomAssetLoader::LoadPixelShader(const CustomAssetLibrary::AssetID& asset_id,
-                                   std::shared_ptr<CustomAssetLibrary> library)
+bool CustomAssetLoader::ResizeWorkerThreads(u32 num_worker_threads)
 {
-  return LoadOrCreateAsset<PixelShaderAsset>(asset_id, m_pixel_shaders, std::move(library));
+  if (m_worker_threads.size() == num_worker_threads)
+    return true;
+
+  StopWorkerThreads();
+  return StartWorkerThreads(num_worker_threads);
 }
 
-std::shared_ptr<MaterialAsset>
-CustomAssetLoader::LoadMaterial(const CustomAssetLibrary::AssetID& asset_id,
-                                std::shared_ptr<CustomAssetLibrary> library)
+bool CustomAssetLoader::HasWorkerThreads() const
 {
-  return LoadOrCreateAsset<MaterialAsset>(asset_id, m_materials, std::move(library));
+  return !m_worker_threads.empty();
 }
 
-std::shared_ptr<MeshAsset> CustomAssetLoader::LoadMesh(const CustomAssetLibrary::AssetID& asset_id,
-                                                       std::shared_ptr<CustomAssetLibrary> library)
+void CustomAssetLoader::StopWorkerThreads()
 {
-  return LoadOrCreateAsset<MeshAsset>(asset_id, m_meshes, std::move(library));
+  if (!HasWorkerThreads())
+    return;
+
+  // Signal worker threads to stop, and wake all of them.
+  {
+    std::lock_guard guard(m_assets_to_load_lock);
+    m_exit_flag.Set();
+    m_worker_thread_wake.notify_all();
+  }
+
+  // Wait for worker threads to exit.
+  for (std::thread& thr : m_worker_threads)
+    thr.join();
+  m_worker_threads.clear();
+  m_exit_flag.Clear();
 }
+
+void CustomAssetLoader::WorkerThreadRun(u32 thread_index)
+{
+  Common::SetCurrentThreadName(fmt::format("Asset Loader {}", thread_index).c_str());
+
+  std::unique_lock load_lock(m_assets_to_load_lock);
+  while (true)
+  {
+    m_worker_thread_wake.wait(load_lock,
+                              [&] { return !m_assets_to_load.empty() || m_exit_flag.IsSet(); });
+
+    if (m_exit_flag.IsSet())
+      return;
+
+    // If more memory than allowed has already been loaded, we will load nothing more
+    //  until the next ScheduleAssetsToLoad from Manager.
+    if (m_change_in_memory > m_allowed_memory)
+    {
+      m_assets_to_load.clear();
+      continue;
+    }
+
+    auto* const item = m_assets_to_load.front();
+    m_assets_to_load.pop_front();
+
+    // Make sure another thread isn't loading this handle.
+    if (!m_handles_in_progress.insert(item->GetHandle()).second)
+      continue;
+
+    load_lock.unlock();
+
+    // Unload previously loaded asset.
+    m_change_in_memory -= item->Unload();
+
+    const std::size_t bytes_loaded = item->Load();
+    m_change_in_memory += s64(bytes_loaded);
+
+    load_lock.lock();
+
+    {
+      INFO_LOG_FMT(VIDEO, "CustomAssetLoader thread {} loaded: {} ({})", thread_index,
+                   item->GetAssetId(), UICommon::FormatSize(bytes_loaded));
+
+      std::lock_guard lk{m_assets_loaded_lock};
+      m_asset_handles_loaded.emplace_back(item->GetHandle(), bytes_loaded > 0);
+
+      // Make sure no other threads try to re-process this item.
+      // Manager will take the handles and re-ScheduleAssetsToLoad based on timestamps if needed.
+      std::erase(m_assets_to_load, item);
+    }
+
+    m_handles_in_progress.erase(item->GetHandle());
+  }
+}
+
+auto CustomAssetLoader::TakeLoadResults() -> LoadResults
+{
+  std::lock_guard guard(m_assets_loaded_lock);
+  return {std::move(m_asset_handles_loaded), m_change_in_memory.exchange(0)};
+}
+
+void CustomAssetLoader::ScheduleAssetsToLoad(std::list<CustomAsset*> assets_to_load,
+                                             u64 allowed_memory)
+{
+  if (assets_to_load.empty()) [[unlikely]]
+    return;
+
+  // There's new assets to process, notify worker threads
+  std::lock_guard guard(m_assets_to_load_lock);
+  m_allowed_memory = allowed_memory;
+  m_assets_to_load = std::move(assets_to_load);
+  m_worker_thread_wake.notify_all();
+}
+
+void CustomAssetLoader::Reset(bool restart_worker_threads)
+{
+  const std::size_t worker_thread_count = m_worker_threads.size();
+  StopWorkerThreads();
+
+  m_assets_to_load.clear();
+  m_asset_handles_loaded.clear();
+  m_allowed_memory = 0;
+  m_change_in_memory = 0;
+
+  if (restart_worker_threads)
+  {
+    StartWorkerThreads(static_cast<u32>(worker_thread_count));
+  }
+}
+
 }  // namespace VideoCommon

Source/Core/VideoCommon/Assets/CustomAssetLoader.h

@@ -1,27 +1,24 @@
-// Copyright 2023 Dolphin Emulator Project
+// Copyright 2025 Dolphin Emulator Project
 // SPDX-License-Identifier: GPL-2.0-or-later
 
 #pragma once
 
-#include <chrono>
-#include <map>
-#include <memory>
+#include <atomic>
+#include <condition_variable>
+#include <list>
 #include <mutex>
+#include <set>
 #include <thread>
+#include <vector>
 
 #include "Common/Flag.h"
-#include "Common/Logging/Log.h"
-#include "Common/WorkQueueThread.h"
 #include "VideoCommon/Assets/CustomAsset.h"
-#include "VideoCommon/Assets/MaterialAsset.h"
-#include "VideoCommon/Assets/MeshAsset.h"
-#include "VideoCommon/Assets/ShaderAsset.h"
-#include "VideoCommon/Assets/TextureAsset.h"
 
 namespace VideoCommon
 {
-// This class is responsible for loading data asynchronously when requested
-// and watches that data asynchronously reloading it if it changes
+// This class takes any number of assets
+// and loads them across a configurable
+// thread pool
 class CustomAssetLoader
 {
 public:
@@ -32,77 +29,54 @@ public:
   CustomAssetLoader& operator=(const CustomAssetLoader&) = delete;
   CustomAssetLoader& operator=(CustomAssetLoader&&) = delete;
 
-  void Init();
+  void Initialize();
   void Shutdown();
 
-  // The following Load* functions will load or create an asset associated
-  // with the given asset id
-  // Loads happen asynchronously where the data will be set now or in the future
-  // Callees are expected to query the underlying data with 'GetData()'
-  // from the 'CustomLoadableAsset' class to determine if the data is ready for use
-  std::shared_ptr<GameTextureAsset> LoadGameTexture(const CustomAssetLibrary::AssetID& asset_id,
-                                                    std::shared_ptr<CustomAssetLibrary> library);
+  using AssetHandle = std::pair<std::size_t, bool>;
+  struct LoadResults
 
-  std::shared_ptr<PixelShaderAsset> LoadPixelShader(const CustomAssetLibrary::AssetID& asset_id,
-                                                    std::shared_ptr<CustomAssetLibrary> library);
+  {
+    std::vector<AssetHandle> asset_handles;
+    s64 change_in_memory;
+  };
 
-  std::shared_ptr<MaterialAsset> LoadMaterial(const CustomAssetLibrary::AssetID& asset_id,
-                                              std::shared_ptr<CustomAssetLibrary> library);
+  // Returns a vector of loaded asset handle / loaded result pairs
+  //  and the change in memory.
+  LoadResults TakeLoadResults();
 
-  std::shared_ptr<MeshAsset> LoadMesh(const CustomAssetLibrary::AssetID& asset_id,
-                                      std::shared_ptr<CustomAssetLibrary> library);
+  // Schedule assets to load on the worker threads
+  //  and set how much memory is available for loading these additional assets.
+  void ScheduleAssetsToLoad(std::list<CustomAsset*> assets_to_load, u64 allowed_memory);
+
+  void Reset(bool restart_worker_threads = true);
 
 private:
-  // TODO C++20: use a 'derived_from' concept against 'CustomAsset' when available
-  template <typename AssetType>
-  std::shared_ptr<AssetType>
-  LoadOrCreateAsset(const CustomAssetLibrary::AssetID& asset_id,
-                    std::map<CustomAssetLibrary::AssetID, std::weak_ptr<AssetType>>& asset_map,
-                    std::shared_ptr<CustomAssetLibrary> library)
-  {
-    auto [it, inserted] = asset_map.try_emplace(asset_id);
-    if (!inserted)
-    {
-      auto shared = it->second.lock();
-      if (shared)
-        return shared;
-    }
-    std::shared_ptr<AssetType> ptr(new AssetType(std::move(library), asset_id), [&](AssetType* a) {
-      {
-        std::lock_guard lk(m_asset_load_lock);
-        m_total_bytes_loaded -= a->GetByteSizeInMemory();
-        m_assets_to_monitor.erase(a->GetAssetId());
-        if (m_max_memory_available >= m_total_bytes_loaded && m_memory_exceeded)
-        {
-          INFO_LOG_FMT(VIDEO, "Asset memory went below limit, new assets can begin loading.");
-          m_memory_exceeded = false;
-        }
-      }
-      delete a;
-    });
-    it->second = ptr;
-    m_asset_load_thread.Push(it->second);
-    return ptr;
-  }
+  bool StartWorkerThreads(u32 num_worker_threads);
+  bool ResizeWorkerThreads(u32 num_worker_threads);
+  bool HasWorkerThreads() const;
+  void StopWorkerThreads();
 
-  static constexpr auto TIME_BETWEEN_ASSET_MONITOR_CHECKS = std::chrono::milliseconds{500};
+  void WorkerThreadRun(u32 thread_index);
 
-  std::map<CustomAssetLibrary::AssetID, std::weak_ptr<GameTextureAsset>> m_game_textures;
-  std::map<CustomAssetLibrary::AssetID, std::weak_ptr<PixelShaderAsset>> m_pixel_shaders;
-  std::map<CustomAssetLibrary::AssetID, std::weak_ptr<MaterialAsset>> m_materials;
-  std::map<CustomAssetLibrary::AssetID, std::weak_ptr<MeshAsset>> m_meshes;
-  std::thread m_asset_monitor_thread;
-  Common::Flag m_asset_monitor_thread_shutdown;
+  Common::Flag m_exit_flag;
 
-  std::size_t m_total_bytes_loaded = 0;
-  std::size_t m_max_memory_available = 0;
-  std::atomic_bool m_memory_exceeded = false;
+  std::vector<std::thread> m_worker_threads;
 
-  std::map<CustomAssetLibrary::AssetID, std::weak_ptr<CustomAsset>> m_assets_to_monitor;
+  std::mutex m_assets_to_load_lock;
+  std::list<CustomAsset*> m_assets_to_load;
 
-  // Use a recursive mutex to handle the scenario where an asset goes out of scope while
-  // iterating over the assets to monitor which calls the lock above in 'LoadOrCreateAsset'
-  std::recursive_mutex m_asset_load_lock;
-  Common::WorkQueueThread<std::weak_ptr<CustomAsset>> m_asset_load_thread;
+  std::condition_variable m_worker_thread_wake;
+
+  std::vector<AssetHandle> m_asset_handles_loaded;
+
+  // Memory available to load new assets.
+  s64 m_allowed_memory = 0;
+
+  // Change in memory from just-loaded/unloaded asset results yet to be taken by the Manager.
+  std::atomic<s64> m_change_in_memory = 0;
+
+  std::mutex m_assets_loaded_lock;
+
+  std::set<std::size_t> m_handles_in_progress;
 };
 }  // namespace VideoCommon

Source/Core/VideoCommon/Assets/CustomResourceManager.cpp

@@ -0,0 +1,229 @@
+// Copyright 2025 Dolphin Emulator Project
+// SPDX-License-Identifier: GPL-2.0-or-later
+
+#include "VideoCommon/Assets/CustomResourceManager.h"
+
+#include "Common/Logging/Log.h"
+#include "Common/MemoryUtil.h"
+
+#include "UICommon/UICommon.h"
+
+#include "VideoCommon/Assets/CustomAsset.h"
+#include "VideoCommon/Assets/TextureAsset.h"
+#include "VideoCommon/VideoEvents.h"
+
+namespace VideoCommon
+{
+void CustomResourceManager::Initialize()
+{
+  // Use half of available system memory but leave at least 2GiB unused for system stability.
+  constexpr size_t must_keep_unused = 2 * size_t(1024 * 1024 * 1024);
+
+  const size_t sys_mem = Common::MemPhysical();
+  const size_t keep_unused_mem = std::max(sys_mem / 2, std::min(sys_mem, must_keep_unused));
+
+  m_max_ram_available = sys_mem - keep_unused_mem;
+
+  if (m_max_ram_available == 0)
+    ERROR_LOG_FMT(VIDEO, "Not enough system memory for custom resources.");
+
+  m_asset_loader.Initialize();
+
+  m_xfb_event =
+      AfterFrameEvent::Register([this](Core::System&) { XFBTriggered(); }, "CustomResourceManager");
+}
+
+void CustomResourceManager::Shutdown()
+{
+  Reset();
+
+  m_asset_loader.Shutdown();
+}
+
+void CustomResourceManager::Reset()
+{
+  m_asset_loader.Reset(true);
+
+  m_active_assets = {};
+  m_pending_assets = {};
+  m_asset_handle_to_data.clear();
+  m_asset_id_to_handle.clear();
+  m_texture_data_asset_cache.clear();
+  m_dirty_assets.clear();
+  m_ram_used = 0;
+}
+
+void CustomResourceManager::MarkAssetDirty(const CustomAssetLibrary::AssetID& asset_id)
+{
+  std::lock_guard guard(m_dirty_mutex);
+  m_dirty_assets.insert(asset_id);
+}
+
+CustomResourceManager::TextureTimePair CustomResourceManager::GetTextureDataFromAsset(
+    const CustomAssetLibrary::AssetID& asset_id,
+    std::shared_ptr<VideoCommon::CustomAssetLibrary> library)
+{
+  auto& resource = m_texture_data_asset_cache[asset_id];
+  if (resource.asset_data != nullptr &&
+      resource.asset_data->load_status == AssetData::LoadStatus::ResourceDataAvailable)
+  {
+    m_active_assets.MakeAssetHighestPriority(resource.asset->GetHandle(), resource.asset);
+    return {resource.texture_data, resource.asset->GetLastLoadedTime()};
+  }
+
+  // If there is an error, don't try and load again until the error is fixed
+  if (resource.asset_data != nullptr && resource.asset_data->has_load_error)
+    return {};
+
+  LoadTextureDataAsset(asset_id, std::move(library), &resource);
+  m_active_assets.MakeAssetHighestPriority(resource.asset->GetHandle(), resource.asset);
+
+  return {};
+}
+
+void CustomResourceManager::LoadTextureDataAsset(
+    const CustomAssetLibrary::AssetID& asset_id,
+    std::shared_ptr<VideoCommon::CustomAssetLibrary> library, InternalTextureDataResource* resource)
+{
+  if (!resource->asset)
+  {
+    resource->asset =
+        CreateAsset<TextureAsset>(asset_id, AssetData::AssetType::TextureData, std::move(library));
+    resource->asset_data = &m_asset_handle_to_data[resource->asset->GetHandle()];
+  }
+
+  auto texture_data = resource->asset->GetData();
+  if (!texture_data || resource->asset_data->load_status == AssetData::LoadStatus::PendingReload)
+  {
+    // Tell the system we are still interested in loading this asset
+    const auto asset_handle = resource->asset->GetHandle();
+    m_pending_assets.MakeAssetHighestPriority(asset_handle,
+                                              m_asset_handle_to_data[asset_handle].asset.get());
+  }
+  else if (resource->asset_data->load_status == AssetData::LoadStatus::LoadFinished)
+  {
+    resource->texture_data = std::move(texture_data);
+    resource->asset_data->load_status = AssetData::LoadStatus::ResourceDataAvailable;
+  }
+}
+
+void CustomResourceManager::XFBTriggered()
+{
+  ProcessDirtyAssets();
+  ProcessLoadedAssets();
+
+  if (m_ram_used > m_max_ram_available)
+  {
+    RemoveAssetsUntilBelowMemoryLimit();
+  }
+
+  if (m_pending_assets.IsEmpty())
+    return;
+
+  if (m_ram_used > m_max_ram_available)
+    return;
+
+  const u64 allowed_memory = m_max_ram_available - m_ram_used;
+  m_asset_loader.ScheduleAssetsToLoad(m_pending_assets.Elements(), allowed_memory);
+}
+
+void CustomResourceManager::ProcessDirtyAssets()
+{
+  decltype(m_dirty_assets) dirty_assets;
+
+  if (const auto lk = std::unique_lock{m_dirty_mutex, std::try_to_lock})
+    std::swap(dirty_assets, m_dirty_assets);
+
+  const auto now = CustomAsset::ClockType::now();
+  for (const auto& asset_id : dirty_assets)
+  {
+    if (const auto it = m_asset_id_to_handle.find(asset_id); it != m_asset_id_to_handle.end())
+    {
+      const auto asset_handle = it->second;
+      AssetData& asset_data = m_asset_handle_to_data[asset_handle];
+      asset_data.load_status = AssetData::LoadStatus::PendingReload;
+      asset_data.load_request_time = now;
+
+      // Asset was reloaded, clear any errors we might have
+      asset_data.has_load_error = false;
+
+      m_pending_assets.InsertAsset(it->second, asset_data.asset.get());
+
+      DEBUG_LOG_FMT(VIDEO, "Dirty asset pending reload: {}", asset_data.asset->GetAssetId());
+    }
+  }
+}
+
+void CustomResourceManager::ProcessLoadedAssets()
+{
+  const auto load_results = m_asset_loader.TakeLoadResults();
+
+  // Update the ram with the change in memory from the loader
+  //
+  // Note: Assets with outstanding reload requests will have
+  // two copies in memory temporarily (the old data stored in
+  // the asset shared_ptr that the resource manager owns, and
+  // the new data loaded from the loader in the asset's shared_ptr)
+  // This temporary duplication will not be reflected in the
+  // resource manager's ram used
+  m_ram_used += load_results.change_in_memory;
+
+  for (const auto& [handle, load_successful] : load_results.asset_handles)
+  {
+    AssetData& asset_data = m_asset_handle_to_data[handle];
+
+    // If we have a reload request that is newer than our loaded time
+    // we need to wait for another reload.
+    if (asset_data.load_request_time > asset_data.asset->GetLastLoadedTime())
+      continue;
+
+    m_pending_assets.RemoveAsset(handle);
+
+    asset_data.load_request_time = {};
+    if (!load_successful)
+    {
+      asset_data.has_load_error = true;
+    }
+    else
+    {
+      m_active_assets.InsertAsset(handle, asset_data.asset.get());
+      asset_data.load_status = AssetData::LoadStatus::LoadFinished;
+    }
+  }
+}
+
+void CustomResourceManager::RemoveAssetsUntilBelowMemoryLimit()
+{
+  const u64 threshold_ram = m_max_ram_available * 8 / 10;
+
+  if (m_ram_used > threshold_ram)
+  {
+    INFO_LOG_FMT(VIDEO, "Memory usage over threshold: {}", UICommon::FormatSize(m_ram_used));
+  }
+
+  // Clear out least recently used resources until
+  // we get safely in our threshold
+  while (m_ram_used > threshold_ram && m_active_assets.Size() > 0)
+  {
+    auto* const asset = m_active_assets.RemoveLowestPriorityAsset();
+
+    AssetData& asset_data = m_asset_handle_to_data[asset->GetHandle()];
+
+    // Remove the resource manager's cached entry with its asset data
+    if (asset_data.type == AssetData::AssetType::TextureData)
+    {
+      m_texture_data_asset_cache.erase(asset->GetAssetId());
+    }
+    // Remove the asset's copy
+    const std::size_t bytes_unloaded = asset_data.asset->Unload();
+    m_ram_used -= bytes_unloaded;
+
+    asset_data.load_status = AssetData::LoadStatus::Unloaded;
+    asset_data.load_request_time = {};
+
+    INFO_LOG_FMT(VIDEO, "Unloading asset: {} ({})", asset_data.asset->GetAssetId(),
+                 UICommon::FormatSize(bytes_unloaded));
+  }
+}
+
+}  // namespace VideoCommon

Source/Core/VideoCommon/Assets/CustomResourceManager.h

@@ -0,0 +1,215 @@
+// Copyright 2025 Dolphin Emulator Project
+// SPDX-License-Identifier: GPL-2.0-or-later
+
+#pragma once
+
+#include <list>
+#include <map>
+#include <memory>
+#include <set>
+#include <vector>
+
+#include "Common/CommonTypes.h"
+#include "Common/HookableEvent.h"
+
+#include "VideoCommon/Assets/CustomAsset.h"
+#include "VideoCommon/Assets/CustomAssetLibrary.h"
+#include "VideoCommon/Assets/CustomAssetLoader.h"
+#include "VideoCommon/Assets/CustomTextureData.h"
+
+namespace VideoCommon
+{
+class TextureAsset;
+
+// The resource manager manages custom resources (textures, shaders, meshes)
+// called assets.  These assets are loaded using a priority system,
+// where assets requested more often gets loaded first.  This system
+// also tracks memory usage and if memory usage goes over a calculated limit,
+// then assets will be purged with older assets being targeted first.
+class CustomResourceManager
+{
+public:
+  void Initialize();
+  void Shutdown();
+
+  void Reset();
+
+  // Request that an asset be reloaded
+  void MarkAssetDirty(const CustomAssetLibrary::AssetID& asset_id);
+
+  void XFBTriggered();
+
+  using TextureTimePair = std::pair<std::shared_ptr<CustomTextureData>, CustomAsset::TimeType>;
+
+  // Returns a pair with the custom texture data and the time it was last loaded
+  // Callees are not expected to hold onto the shared_ptr as that will prevent
+  // the resource manager from being able to properly release data
+  TextureTimePair GetTextureDataFromAsset(const CustomAssetLibrary::AssetID& asset_id,
+                                          std::shared_ptr<VideoCommon::CustomAssetLibrary> library);
+
+private:
+  // A generic interface to describe an assets' type
+  // and load state
+  struct AssetData
+  {
+    std::unique_ptr<CustomAsset> asset;
+    CustomAsset::TimeType load_request_time = {};
+    bool has_load_error = false;
+
+    enum class AssetType
+    {
+      TextureData
+    };
+    AssetType type;
+
+    enum class LoadStatus
+    {
+      PendingReload,
+      LoadFinished,
+      ResourceDataAvailable,
+      Unloaded,
+    };
+    LoadStatus load_status = LoadStatus::PendingReload;
+  };
+
+  // A structure to represent some raw texture data
+  // (this data hasn't hit the GPU yet, used for custom textures)
+  struct InternalTextureDataResource
+  {
+    AssetData* asset_data = nullptr;
+    VideoCommon::TextureAsset* asset = nullptr;
+    std::shared_ptr<CustomTextureData> texture_data;
+  };
+
+  void LoadTextureDataAsset(const CustomAssetLibrary::AssetID& asset_id,
+                            std::shared_ptr<VideoCommon::CustomAssetLibrary> library,
+                            InternalTextureDataResource* resource);
+
+  void ProcessDirtyAssets();
+  void ProcessLoadedAssets();
+  void RemoveAssetsUntilBelowMemoryLimit();
+
+  template <typename T>
+  T* CreateAsset(const CustomAssetLibrary::AssetID& asset_id, AssetData::AssetType asset_type,
+                 std::shared_ptr<VideoCommon::CustomAssetLibrary> library)
+  {
+    const auto [it, added] =
+        m_asset_id_to_handle.try_emplace(asset_id, m_asset_handle_to_data.size());
+
+    if (added)
+    {
+      AssetData asset_data;
+      asset_data.asset = std::make_unique<T>(library, asset_id, it->second);
+      asset_data.type = asset_type;
+      asset_data.load_request_time = {};
+      asset_data.has_load_error = false;
+
+      m_asset_handle_to_data.insert_or_assign(it->second, std::move(asset_data));
+    }
+    auto& asset_data_from_handle = m_asset_handle_to_data[it->second];
+    asset_data_from_handle.load_status = AssetData::LoadStatus::PendingReload;
+
+    return static_cast<T*>(asset_data_from_handle.asset.get());
+  }
+
+  // Maintains a priority-sorted list of assets.
+  // Used to figure out which assets to load or unload first.
+  // Most recently used assets get marked with highest priority.
+  class AssetPriorityQueue
+  {
+  public:
+    const auto& Elements() const { return m_assets; }
+
+    // Inserts or moves the asset to the top of the queue.
+    void MakeAssetHighestPriority(u64 asset_handle, CustomAsset* asset)
+    {
+      RemoveAsset(asset_handle);
+      m_assets.push_front(asset);
+
+      // See CreateAsset for how a handle gets defined
+      if (asset_handle >= m_iterator_lookup.size())
+        m_iterator_lookup.resize(asset_handle + 1, m_assets.end());
+
+      m_iterator_lookup[asset_handle] = m_assets.begin();
+    }
+
+    // Inserts an asset at lowest priority or
+    //  does nothing if asset is already in the queue.
+    void InsertAsset(u64 asset_handle, CustomAsset* asset)
+    {
+      if (asset_handle >= m_iterator_lookup.size())
+        m_iterator_lookup.resize(asset_handle + 1, m_assets.end());
+
+      if (m_iterator_lookup[asset_handle] == m_assets.end())
+      {
+        m_assets.push_back(asset);
+        m_iterator_lookup[asset_handle] = std::prev(m_assets.end());
+      }
+    }
+
+    CustomAsset* RemoveLowestPriorityAsset()
+    {
+      if (m_assets.empty()) [[unlikely]]
+        return nullptr;
+      auto* const ret = m_assets.back();
+      if (ret != nullptr)
+      {
+        m_iterator_lookup[ret->GetHandle()] = m_assets.end();
+      }
+      m_assets.pop_back();
+      return ret;
+    }
+
+    void RemoveAsset(u64 asset_handle)
+    {
+      if (asset_handle >= m_iterator_lookup.size())
+        return;
+
+      const auto iter = m_iterator_lookup[asset_handle];
+      if (iter != m_assets.end())
+      {
+        m_assets.erase(iter);
+        m_iterator_lookup[asset_handle] = m_assets.end();
+      }
+    }
+
+    bool IsEmpty() const { return m_assets.empty(); }
+
+    std::size_t Size() const { return m_assets.size(); }
+
+  private:
+    std::list<CustomAsset*> m_assets;
+
+    // Handle-to-iterator lookup for fast access.
+    // Grows as needed on insert.
+    std::vector<decltype(m_assets)::iterator> m_iterator_lookup;
+  };
+
+  // Assets that are currently active in memory, in order of most recently used by the game.
+  AssetPriorityQueue m_active_assets;
+
+  // Assets that need to be loaded.
+  // e.g. Because the game tried to use them or because they changed on disk.
+  // Ordered by most recently used.
+  AssetPriorityQueue m_pending_assets;
+
+  std::map<std::size_t, AssetData> m_asset_handle_to_data;
+  std::map<CustomAssetLibrary::AssetID, std::size_t> m_asset_id_to_handle;
+
+  // Memory used by currently "loaded" assets.
+  u64 m_ram_used = 0;
+
+  // A calculated amount of memory to avoid exceeding.
+  u64 m_max_ram_available = 0;
+
+  std::map<CustomAssetLibrary::AssetID, InternalTextureDataResource> m_texture_data_asset_cache;
+
+  std::mutex m_dirty_mutex;
+  std::set<CustomAssetLibrary::AssetID> m_dirty_assets;
+
+  CustomAssetLoader m_asset_loader;
+
+  Common::EventHook m_xfb_event;
+};
+
+}  // namespace VideoCommon

Source/Core/VideoCommon/Assets/DirectFilesystemAssetLibrary.cpp

@@ -13,30 +13,19 @@
 #include "Common/JsonUtil.h"
 #include "Common/Logging/Log.h"
 #include "Common/StringUtil.h"
+#include "Core/System.h"
+#include "VideoCommon/Assets/CustomResourceManager.h"
 #include "VideoCommon/Assets/MaterialAsset.h"
 #include "VideoCommon/Assets/MeshAsset.h"
 #include "VideoCommon/Assets/ShaderAsset.h"
 #include "VideoCommon/Assets/TextureAsset.h"
+#include "VideoCommon/Assets/TextureAssetUtils.h"
 #include "VideoCommon/RenderState.h"
 
 namespace VideoCommon
 {
 namespace
 {
-std::chrono::system_clock::time_point FileTimeToSysTime(std::filesystem::file_time_type file_time)
-{
-#ifdef _WIN32
-  return std::chrono::clock_cast<std::chrono::system_clock>(file_time);
-#else
-  // Note: all compilers should switch to chrono::clock_cast
-  // once it is available for use
-  const auto system_time_now = std::chrono::system_clock::now();
-  const auto file_time_now = decltype(file_time)::clock::now();
-  return std::chrono::time_point_cast<std::chrono::system_clock::duration>(
-      file_time - file_time_now + system_time_now);
-#endif
-}
-
 std::size_t GetAssetSize(const CustomTextureData& data)
 {
   std::size_t total = 0;
@@ -50,30 +39,6 @@ std::size_t GetAssetSize(const CustomTextureData& data)
   return total;
 }
 }  // namespace
-CustomAssetLibrary::TimeType
-DirectFilesystemAssetLibrary::GetLastAssetWriteTime(const AssetID& asset_id) const
-{
-  std::lock_guard lk(m_lock);
-  if (auto iter = m_assetid_to_asset_map_path.find(asset_id);
-      iter != m_assetid_to_asset_map_path.end())
-  {
-    const auto& asset_map_path = iter->second;
-    CustomAssetLibrary::TimeType max_entry;
-    for (const auto& [key, value] : asset_map_path)
-    {
-      std::error_code ec;
-      const auto tp = std::filesystem::last_write_time(value, ec);
-      if (ec)
-        continue;
-      auto tp_sys = FileTimeToSysTime(tp);
-      if (tp_sys > max_entry)
-        max_entry = tp_sys;
-    }
-    return max_entry;
-  }
-
-  return {};
-}
 
 CustomAssetLibrary::LoadInfo DirectFilesystemAssetLibrary::LoadPixelShader(const AssetID& asset_id,
                                                                            PixelShaderData* data)
@@ -158,7 +123,7 @@ CustomAssetLibrary::LoadInfo DirectFilesystemAssetLibrary::LoadPixelShader(const
   if (!PixelShaderData::FromJson(asset_id, root_obj, data))
     return {};
 
-  return LoadInfo{approx_mem_size, GetLastAssetWriteTime(asset_id)};
+  return LoadInfo{approx_mem_size};
 }
 
 CustomAssetLibrary::LoadInfo DirectFilesystemAssetLibrary::LoadMaterial(const AssetID& asset_id,
@@ -216,7 +181,7 @@ CustomAssetLibrary::LoadInfo DirectFilesystemAssetLibrary::LoadMaterial(const As
     return {};
   }
 
-  return LoadInfo{metadata_size, GetLastAssetWriteTime(asset_id)};
+  return LoadInfo{metadata_size};
 }
 
 CustomAssetLibrary::LoadInfo DirectFilesystemAssetLibrary::LoadMesh(const AssetID& asset_id,
@@ -311,11 +276,41 @@ CustomAssetLibrary::LoadInfo DirectFilesystemAssetLibrary::LoadMesh(const AssetI
   if (!MeshData::FromJson(asset_id, root_obj, data))
     return {};
 
-  return LoadInfo{approx_mem_size, GetLastAssetWriteTime(asset_id)};
+  return LoadInfo{approx_mem_size};
 }
 
 CustomAssetLibrary::LoadInfo DirectFilesystemAssetLibrary::LoadTexture(const AssetID& asset_id,
-                                                                       TextureData* data)
+                                                                       CustomTextureData* data)
+{
+  const auto asset_map = GetAssetMapForID(asset_id);
+  if (asset_map.empty())
+  {
+    ERROR_LOG_FMT(VIDEO, "Asset '{}' error - raw texture expected to have one or two files mapped!",
+                  asset_id);
+    return {};
+  }
+
+  const auto texture_path = asset_map.find("texture");
+
+  if (texture_path == asset_map.end())
+  {
+    ERROR_LOG_FMT(VIDEO, "Asset '{}' expected to have a texture entry mapped!", asset_id);
+    return {};
+  }
+
+  if (!LoadTextureDataFromFile(asset_id, texture_path->second,
+                               TextureAndSamplerData::Type::Type_Texture2D, data))
+  {
+    return {};
+  }
+  if (!PurgeInvalidMipsFromTextureData(asset_id, data))
+    return {};
+
+  return LoadInfo{GetAssetSize(*data)};
+}
+
+CustomAssetLibrary::LoadInfo DirectFilesystemAssetLibrary::LoadTexture(const AssetID& asset_id,
+                                                                       TextureAndSamplerData* data)
 {
   const auto asset_map = GetAssetMapForID(asset_id);
 
@@ -368,7 +363,7 @@ CustomAssetLibrary::LoadInfo DirectFilesystemAssetLibrary::LoadTexture(const Ass
     }
 
     const auto& root_obj = root.get<picojson::object>();
-    if (!TextureData::FromJson(asset_id, root_obj, data))
+    if (!TextureAndSamplerData::FromJson(asset_id, root_obj, data))
     {
       return {};
     }
@@ -376,128 +371,62 @@ CustomAssetLibrary::LoadInfo DirectFilesystemAssetLibrary::LoadTexture(const Ass
   else
   {
     data->m_sampler = RenderState::GetLinearSamplerState();
-    data->m_type = TextureData::Type::Type_Texture2D;
+    data->m_type = TextureAndSamplerData::Type::Type_Texture2D;
   }
 
-  auto ext = PathToString(texture_path->second.extension());
-  Common::ToLower(&ext);
-  if (ext == ".dds")
-  {
-    if (!LoadDDSTexture(&data->m_texture, PathToString(texture_path->second)))
-    {
-      ERROR_LOG_FMT(VIDEO, "Asset '{}' error - could not load dds texture!", asset_id);
-      return {};
-    }
+  if (!LoadTextureDataFromFile(asset_id, texture_path->second, data->m_type, &data->m_texture))
+    return {};
+  if (!PurgeInvalidMipsFromTextureData(asset_id, &data->m_texture))
+    return {};
 
-    if (data->m_texture.m_slices.empty()) [[unlikely]]
-      data->m_texture.m_slices.push_back({});
-
-    if (!LoadMips(texture_path->second, &data->m_texture.m_slices[0]))
-      return {};
-
-    return LoadInfo{GetAssetSize(data->m_texture) + metadata_size, GetLastAssetWriteTime(asset_id)};
-  }
-  else if (ext == ".png")
-  {
-    // PNG could support more complicated texture types in the future
-    // but for now just error
-    if (data->m_type != TextureData::Type::Type_Texture2D)
-    {
-      ERROR_LOG_FMT(VIDEO, "Asset '{}' error - PNG is not supported for texture type '{}'!",
-                    asset_id, data->m_type);
-      return {};
-    }
-
-    // If we have no slices, create one
-    if (data->m_texture.m_slices.empty())
-      data->m_texture.m_slices.push_back({});
-
-    auto& slice = data->m_texture.m_slices[0];
-    // If we have no levels, create one to pass into LoadPNGTexture
-    if (slice.m_levels.empty())
-      slice.m_levels.push_back({});
-
-    if (!LoadPNGTexture(&slice.m_levels[0], PathToString(texture_path->second)))
-    {
-      ERROR_LOG_FMT(VIDEO, "Asset '{}' error - could not load png texture!", asset_id);
-      return {};
-    }
-
-    if (!LoadMips(texture_path->second, &slice))
-      return {};
-
-    return LoadInfo{GetAssetSize(data->m_texture) + metadata_size, GetLastAssetWriteTime(asset_id)};
-  }
-
-  ERROR_LOG_FMT(VIDEO, "Asset '{}' error - extension '{}' unknown!", asset_id, ext);
-  return {};
+  return LoadInfo{GetAssetSize(data->m_texture) + metadata_size};
 }
 
 void DirectFilesystemAssetLibrary::SetAssetIDMapData(const AssetID& asset_id,
-                                                     AssetMap asset_path_map)
+                                                     VideoCommon::Assets::AssetMap asset_path_map)
 {
-  std::lock_guard lk(m_lock);
-  m_assetid_to_asset_map_path[asset_id] = std::move(asset_path_map);
-}
-
-bool DirectFilesystemAssetLibrary::LoadMips(const std::filesystem::path& asset_path,
-                                            CustomTextureData::ArraySlice* data)
-{
-  if (!data) [[unlikely]]
-    return false;
-
-  std::string path;
-  std::string filename;
-  std::string extension;
-  SplitPath(PathToString(asset_path), &path, &filename, &extension);
-
-  std::string extension_lower = extension;
-  Common::ToLower(&extension_lower);
-
-  // Load additional mip levels
-  for (u32 mip_level = static_cast<u32>(data->m_levels.size());; mip_level++)
+  VideoCommon::Assets::AssetMap previous_asset_map;
   {
-    const auto mip_level_filename = filename + fmt::format("_mip{}", mip_level);
-
-    const auto full_path = path + mip_level_filename + extension;
-    if (!File::Exists(full_path))
-      return true;
-
-    VideoCommon::CustomTextureData::ArraySlice::Level level;
-    if (extension_lower == ".dds")
-    {
-      if (!LoadDDSTexture(&level, full_path, mip_level))
-      {
-        ERROR_LOG_FMT(VIDEO, "Custom mipmap '{}' failed to load", mip_level_filename);
-        return false;
-      }
-    }
-    else if (extension_lower == ".png")
-    {
-      if (!LoadPNGTexture(&level, full_path))
-      {
-        ERROR_LOG_FMT(VIDEO, "Custom mipmap '{}' failed to load", mip_level_filename);
-        return false;
-      }
-    }
-    else
-    {
-      ERROR_LOG_FMT(VIDEO, "Custom mipmap '{}' has unsupported extension", mip_level_filename);
-      return false;
-    }
-
-    data->m_levels.push_back(std::move(level));
+    std::lock_guard lk(m_asset_map_lock);
+    previous_asset_map = m_asset_id_to_asset_map_path[asset_id];
   }
 
-  return true;
+  {
+    std::lock_guard lk(m_path_map_lock);
+    for (const auto& [name, path] : previous_asset_map)
+    {
+      m_path_to_asset_id.erase(PathToString(path));
+    }
+
+    for (const auto& [name, path] : asset_path_map)
+    {
+      m_path_to_asset_id[PathToString(path)] = asset_id;
+    }
+  }
+
+  {
+    std::lock_guard lk(m_asset_map_lock);
+    m_asset_id_to_asset_map_path[asset_id] = std::move(asset_path_map);
+  }
 }
 
-DirectFilesystemAssetLibrary::AssetMap
+void DirectFilesystemAssetLibrary::PathModified(std::string_view path)
+{
+  std::lock_guard lk(m_path_map_lock);
+  if (const auto iter = m_path_to_asset_id.find(path); iter != m_path_to_asset_id.end())
+  {
+    auto& system = Core::System::GetInstance();
+    auto& resource_manager = system.GetCustomResourceManager();
+    resource_manager.MarkAssetDirty(iter->second);
+  }
+}
+
+VideoCommon::Assets::AssetMap
 DirectFilesystemAssetLibrary::GetAssetMapForID(const AssetID& asset_id) const
 {
-  std::lock_guard lk(m_lock);
-  if (auto iter = m_assetid_to_asset_map_path.find(asset_id);
-      iter != m_assetid_to_asset_map_path.end())
+  std::lock_guard lk(m_asset_map_lock);
+  if (auto iter = m_asset_id_to_asset_map_path.find(asset_id);
+      iter != m_asset_id_to_asset_map_path.end())
   {
     return iter->second;
   }