VideoCommon: add custom asset implementation and asset library that can load an asset

Source/Core/VideoCommon/Assets/CustomAsset.cpp

@@ -0,0 +1,45 @@
+// Copyright 2023 Dolphin Emulator Project
+// SPDX-License-Identifier: GPL-2.0-or-later
+
+#include "VideoCommon/Assets/CustomAsset.h"
+
+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)
+{
+}
+
+bool CustomAsset::Load()
+{
+  const auto load_information = LoadImpl(m_asset_id);
+  if (load_information.m_bytes_loaded > 0)
+  {
+    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
+{
+  return m_last_loaded_time;
+}
+
+const CustomAssetLibrary::AssetID& CustomAsset::GetAssetId() const
+{
+  return m_asset_id;
+}
+
+std::size_t CustomAsset::GetByteSizeInMemory() const
+{
+  return m_bytes_loaded;
+}
+
+}  // namespace VideoCommon