1 files changed, 132 insertions, 0 deletions
diff --git a/src/core/file_sys/vfs/vfs_layered.cpp b/src/core/file_sys/vfs/vfs_layered.cpp
new file mode 100644
index 000000000..47b2a3c78
--- /dev/null
+++ b/src/core/file_sys/vfs/vfs_layered.cpp
@@ -0,0 +1,132 @@
+// SPDX-FileCopyrightText: Copyright 2018 yuzu Emulator Project
+// SPDX-License-Identifier: GPL-2.0-or-later
+
+#include <algorithm>
+#include <set>
+#include <unordered_set>
+#include <utility>
+#include "core/file_sys/vfs/vfs_layered.h"
+
+namespace FileSys {
+
+LayeredVfsDirectory::LayeredVfsDirectory(std::vector<VirtualDir> dirs_, std::string name_)
+    : dirs(std::move(dirs_)), name(std::move(name_)) {}
+
+LayeredVfsDirectory::~LayeredVfsDirectory() = default;
+
+VirtualDir LayeredVfsDirectory::MakeLayeredDirectory(std::vector<VirtualDir> dirs,
+                                                     std::string name) {
+    if (dirs.empty())
+        return nullptr;
+    if (dirs.size() == 1)
+        return dirs[0];
+
+    return VirtualDir(new LayeredVfsDirectory(std::move(dirs), std::move(name)));
+}
+
+VirtualFile LayeredVfsDirectory::GetFileRelative(std::string_view path) const {
+    for (const auto& layer : dirs) {
+        const auto file = layer->GetFileRelative(path);
+        if (file != nullptr)
+            return file;
+    }
+
+    return nullptr;
+}
+
+VirtualDir LayeredVfsDirectory::GetDirectoryRelative(std::string_view path) const {
+    std::vector<VirtualDir> out;
+    for (const auto& layer : dirs) {
+        auto dir = layer->GetDirectoryRelative(path);
+        if (dir != nullptr) {
+            out.emplace_back(std::move(dir));
+        }
+    }
+
+    return MakeLayeredDirectory(std::move(out));
+}
+
+VirtualFile LayeredVfsDirectory::GetFile(std::string_view file_name) const {
+    return GetFileRelative(file_name);
+}
+
+VirtualDir LayeredVfsDirectory::GetSubdirectory(std::string_view subdir_name) const {
+    return GetDirectoryRelative(subdir_name);
+}
+
+std::string LayeredVfsDirectory::GetFullPath() const {
+    return dirs[0]->GetFullPath();
+}
+
+std::vector<VirtualFile> LayeredVfsDirectory::GetFiles() const {
+    std::vector<VirtualFile> out;
+    std::unordered_set<std::string> out_names;
+
+    for (const auto& layer : dirs) {
+        for (auto& file : layer->GetFiles()) {
+            const auto [it, is_new] = out_names.emplace(file->GetName());
+            if (is_new) {
+                out.emplace_back(std::move(file));
+            }
+        }
+    }
+
+    return out;
+}
+
+std::vector<VirtualDir> LayeredVfsDirectory::GetSubdirectories() const {
+    std::vector<VirtualDir> out;
+    std::unordered_set<std::string> out_names;
+
+    for (const auto& layer : dirs) {
+        for (const auto& sd : layer->GetSubdirectories()) {
+            out_names.emplace(sd->GetName());
+        }
+    }
+
+    out.reserve(out_names.size());
+    for (const auto& subdir : out_names) {
+        out.emplace_back(GetSubdirectory(subdir));
+    }
+
+    return out;
+}
+
+bool LayeredVfsDirectory::IsWritable() const {
+    return false;
+}
+
+bool LayeredVfsDirectory::IsReadable() const {
+    return true;
+}
+
+std::string LayeredVfsDirectory::GetName() const {
+    return name.empty() ? dirs[0]->GetName() : name;
+}
+
+VirtualDir LayeredVfsDirectory::GetParentDirectory() const {
+    return dirs[0]->GetParentDirectory();
+}
+
+VirtualDir LayeredVfsDirectory::CreateSubdirectory(std::string_view subdir_name) {
+    return nullptr;
+}
+
+VirtualFile LayeredVfsDirectory::CreateFile(std::string_view file_name) {
+    return nullptr;
+}
+
+bool LayeredVfsDirectory::DeleteSubdirectory(std::string_view subdir_name) {
+    return false;
+}
+
+bool LayeredVfsDirectory::DeleteFile(std::string_view file_name) {
+    return false;
+}
+
+bool LayeredVfsDirectory::Rename(std::string_view new_name) {
+    name = new_name;
+    return true;
+}
+
+} // namespace FileSys