4 files changed, 99 insertions, 2 deletions

diff --git a/src/core/CMakeLists.txt b/src/core/CMakeLists.txt
index 45328158f..e8bf68866 100644
--- a/src/core/CMakeLists.txt
+++ b/src/core/CMakeLists.txt
@@ -106,6 +106,8 @@ add_library(core STATIC
     file_sys/system_archive/time_zone_binary.h
     file_sys/vfs.cpp
     file_sys/vfs.h
+    file_sys/vfs_cached.cpp
+    file_sys/vfs_cached.h
     file_sys/vfs_concat.cpp
     file_sys/vfs_concat.h
     file_sys/vfs_layered.cpp
diff --git a/src/core/file_sys/patch_manager.cpp b/src/core/file_sys/patch_manager.cpp
index 4c80e13a9..f786f2add 100644
--- a/src/core/file_sys/patch_manager.cpp
+++ b/src/core/file_sys/patch_manager.cpp
@@ -21,6 +21,7 @@
 #include "core/file_sys/patch_manager.h"
 #include "core/file_sys/registered_cache.h"
 #include "core/file_sys/romfs.h"
+#include "core/file_sys/vfs_cached.h"
 #include "core/file_sys/vfs_layered.h"
 #include "core/file_sys/vfs_vector.h"
 #include "core/hle/service/filesystem/filesystem.h"
@@ -380,11 +381,11 @@ static void ApplyLayeredFS(VirtualFile& romfs, u64 title_id, ContentRecordType t
 
         auto romfs_dir = FindSubdirectoryCaseless(subdir, "romfs");
         if (romfs_dir != nullptr)
-            layers.push_back(std::move(romfs_dir));
+            layers.push_back(std::make_shared<CachedVfsDirectory>(romfs_dir));
 
         auto ext_dir = FindSubdirectoryCaseless(subdir, "romfs_ext");
         if (ext_dir != nullptr)
-            layers_ext.push_back(std::move(ext_dir));
+            layers_ext.push_back(std::make_shared<CachedVfsDirectory>(ext_dir));
     }
 
     // When there are no layers to apply, return early as there is no need to rebuild the RomFS
diff --git a/src/core/file_sys/vfs_cached.cpp b/src/core/file_sys/vfs_cached.cpp
new file mode 100644
index 000000000..c3154ee81
--- /dev/null
+++ b/src/core/file_sys/vfs_cached.cpp
@@ -0,0 +1,63 @@
+// SPDX-FileCopyrightText: Copyright 2023 yuzu Emulator Project
+// SPDX-License-Identifier: GPL-2.0-or-later
+
+#include "core/file_sys/vfs_cached.h"
+#include "core/file_sys/vfs_types.h"
+
+namespace FileSys {
+
+CachedVfsDirectory::CachedVfsDirectory(VirtualDir& source_dir)
+    : name(source_dir->GetName()), parent(source_dir->GetParentDirectory()) {
+    for (auto& dir : source_dir->GetSubdirectories()) {
+        dirs.emplace(dir->GetName(), std::make_shared<CachedVfsDirectory>(dir));
+    }
+    for (auto& file : source_dir->GetFiles()) {
+        files.emplace(file->GetName(), file);
+    }
+}
+
+CachedVfsDirectory::~CachedVfsDirectory() = default;
+
+VirtualFile CachedVfsDirectory::GetFile(std::string_view file_name) const {
+    auto it = files.find(file_name);
+    if (it != files.end()) {
+        return it->second;
+    }
+
+    return nullptr;
+}
+
+VirtualDir CachedVfsDirectory::GetSubdirectory(std::string_view dir_name) const {
+    auto it = dirs.find(dir_name);
+    if (it != dirs.end()) {
+        return it->second;
+    }
+
+    return nullptr;
+}
+
+std::vector<VirtualFile> CachedVfsDirectory::GetFiles() const {
+    std::vector<VirtualFile> out;
+    for (auto& [file_name, file] : files) {
+        out.push_back(file);
+    }
+    return out;
+}
+
+std::vector<VirtualDir> CachedVfsDirectory::GetSubdirectories() const {
+    std::vector<VirtualDir> out;
+    for (auto& [dir_name, dir] : dirs) {
+        out.push_back(dir);
+    }
+    return out;
+}
+
+std::string CachedVfsDirectory::GetName() const {
+    return name;
+}
+
+VirtualDir CachedVfsDirectory::GetParentDirectory() const {
+    return parent;
+}
+
+} // namespace FileSys
diff --git a/src/core/file_sys/vfs_cached.h b/src/core/file_sys/vfs_cached.h
new file mode 100644
index 000000000..113acac12
--- /dev/null
+++ b/src/core/file_sys/vfs_cached.h
@@ -0,0 +1,31 @@
+// SPDX-FileCopyrightText: Copyright 2023 yuzu Emulator Project
+// SPDX-License-Identifier: GPL-2.0-or-later
+
+#pragma once
+
+#include <string_view>
+#include <vector>
+#include "core/file_sys/vfs.h"
+
+namespace FileSys {
+
+class CachedVfsDirectory : public ReadOnlyVfsDirectory {
+public:
+    CachedVfsDirectory(VirtualDir& source_directory);
+
+    ~CachedVfsDirectory() override;
+    VirtualFile GetFile(std::string_view file_name) const override;
+    VirtualDir GetSubdirectory(std::string_view dir_name) const override;
+    std::vector<VirtualFile> GetFiles() const override;
+    std::vector<VirtualDir> GetSubdirectories() const override;
+    std::string GetName() const override;
+    VirtualDir GetParentDirectory() const override;
+
+private:
+    std::string name;
+    VirtualDir parent;
+    std::map<std::string, VirtualDir, std::less<>> dirs;
+    std::map<std::string, VirtualFile, std::less<>> files;
+};
+
+} // namespace FileSys