FileSys: add SaveDataArchive

The error checking of SaveDataArchive is completely different from DiskArchive, so it has to be a new class instead of a subclass of DiskArchive.

src/core/file_sys/savedata_archive.h

@@ -0,0 +1,43 @@
+// Copyright 2016 Citra Emulator Project
+// Licensed under GPLv2 or any later version
+// Refer to the license.txt file included.
+
+#pragma once
+
+#include <string>
+#include "core/file_sys/archive_backend.h"
+#include "core/file_sys/directory_backend.h"
+#include "core/file_sys/file_backend.h"
+#include "core/hle/result.h"
+
+////////////////////////////////////////////////////////////////////////////////////////////////////
+// FileSys namespace
+
+namespace FileSys {
+
+/// Archive backend for general save data archive type (SaveData and SystemSaveData)
+class SaveDataArchive : public ArchiveBackend {
+public:
+    SaveDataArchive(const std::string& mount_point_) : mount_point(mount_point_) {}
+
+    std::string GetName() const override {
+        return "SaveDataArchive: " + mount_point;
+    }
+
+    ResultVal<std::unique_ptr<FileBackend>> OpenFile(const Path& path,
+                                                     const Mode& mode) const override;
+    ResultCode DeleteFile(const Path& path) const override;
+    ResultCode RenameFile(const Path& src_path, const Path& dest_path) const override;
+    ResultCode DeleteDirectory(const Path& path) const override;
+    ResultCode DeleteDirectoryRecursively(const Path& path) const override;
+    ResultCode CreateFile(const Path& path, u64 size) const override;
+    ResultCode CreateDirectory(const Path& path) const override;
+    ResultCode RenameDirectory(const Path& src_path, const Path& dest_path) const override;
+    ResultVal<std::unique_ptr<DirectoryBackend>> OpenDirectory(const Path& path) const override;
+    u64 GetFreeBytes() const override;
+
+protected:
+    std::string mount_point;
+};
+
+} // namespace FileSys