VideoCommon: optimize asset loading system

.gitmodules

@@ -84,3 +84,6 @@
 [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

CMakeLists.txt

@@ -775,6 +775,8 @@ 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/DolphinLib.props

@@ -663,6 +663,8 @@
     <ClInclude Include="VideoCommon\Assets\MeshAsset.h" />
     <ClInclude Include="VideoCommon\Assets\ShaderAsset.h" />
     <ClInclude Include="VideoCommon\Assets\TextureAsset.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" />
@@ -1308,6 +1310,7 @@
     <ClCompile Include="VideoCommon\Assets\MeshAsset.cpp" />
     <ClCompile Include="VideoCommon\Assets\ShaderAsset.cpp" />
     <ClCompile Include="VideoCommon\Assets\TextureAsset.cpp" />
+    <ClCompile Include="VideoCommon\Assets\WatchableFilesystemAssetLibrary.cpp" />
     <ClCompile Include="VideoCommon\AsyncRequests.cpp" />
     <ClCompile Include="VideoCommon\AsyncShaderCompiler.cpp" />
     <ClCompile Include="VideoCommon\BoundingBox.cpp" />

Source/Core/VideoCommon/Assets/CustomAsset.cpp

@@ -6,8 +6,8 @@
 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 session_id)
+    : m_owning_library(std::move(library)), m_asset_id(asset_id), m_session_id(session_id)
 {
 }
 
@@ -34,6 +34,11 @@ const CustomAssetLibrary::TimeType& CustomAsset::GetLastLoadedTime() const
   return m_last_loaded_time;
 }
 
+std::size_t CustomAsset::GetSessionId() const
+{
+  return m_session_id;
+}
+
 const CustomAssetLibrary::AssetID& CustomAsset::GetAssetId() const
 {
   return m_asset_id;

Source/Core/VideoCommon/Assets/CustomAsset.h

@@ -18,7 +18,7 @@ class CustomAsset
 {
 public:
   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;
@@ -39,6 +39,9 @@ class CustomAsset
   // Returns an id that uniquely identifies this asset
   const CustomAssetLibrary::AssetID& GetAssetId() const;
 
+  // Returns an id that is unique to this session
+  std::size_t GetSessionId() const;
+
   // A rough estimate of how much space this asset
   // will take in memroy
   std::size_t GetByteSizeInMemory() const;
@@ -49,6 +52,7 @@ class CustomAsset
 private:
   virtual CustomAssetLibrary::LoadInfo LoadImpl(const CustomAssetLibrary::AssetID& asset_id) = 0;
   CustomAssetLibrary::AssetID m_asset_id;
+  std::size_t m_session_id;
 
   mutable std::mutex m_info_lock;
   std::size_t m_bytes_loaded = 0;