Refactor InnerFAT into Savegame and Extdata

And derive TitleDB from it too.

src/core/extdata.cpp

@@ -0,0 +1,141 @@
+// Copyright 2021 threeSD Project
+// Licensed under GPLv2 or any later version
+// Refer to the license.txt file included.
+
+#include "core/data_container.h"
+#include "core/decryptor.h"
+#include "core/extdata.h"
+
+namespace Core {
+
+Extdata::Extdata(std::string data_path_, const SDMCDecryptor& decryptor_)
+    : data_path(std::move(data_path_)), decryptor(&decryptor_) {
+
+    if (data_path.back() != '/' && data_path.back() != '\\') {
+        data_path += '/';
+    }
+
+    use_decryptor = true;
+    is_good = Init();
+}
+
+Extdata::Extdata(std::string data_path_) : data_path(std::move(data_path_)) {
+    if (data_path.back() != '/' && data_path.back() != '\\') {
+        data_path += '/';
+    }
+
+    use_decryptor = false;
+    is_good = Init();
+}
+
+Extdata::~Extdata() = default;
+
+bool Extdata::CheckMagic() const {
+    if (header.fat_header.magic != MakeMagic('V', 'S', 'X', 'E') ||
+        header.fat_header.version != 0x30000) {
+
+        LOG_ERROR(Core, "File is invalid, decryption errors may have happened.");
+        return false;
+    }
+    return true;
+}
+
+bool Extdata::IsGood() const {
+    return is_good;
+}
+
+bool Extdata::Extract(std::string path) const {
+    if (path.back() != '/' && path.back() != '\\') {
+        path += '/';
+    }
+
+    if (!ExtractDirectory(path, 1)) {
+        return false;
+    }
+
+    // Write format info
+    const auto format_info = GetFormatInfo();
+    return FileUtil::WriteBytesToFile(path + "metadata", &format_info, sizeof(format_info));
+}
+
+std::vector<u8> Extdata::ReadFile(const std::string& path) const {
+    if (use_decryptor) {
+        return decryptor->DecryptFile(path);
+    } else {
+        FileUtil::IOFile file(path, "rb");
+        return file.GetData();
+    }
+}
+
+bool Extdata::Init() {
+    // Read VSXE file
+    auto vsxe_raw = ReadFile(data_path + "00000000/00000001");
+    if (vsxe_raw.empty()) {
+        LOG_ERROR(Core, "Failed to load or decrypt VSXE");
+        return false;
+    }
+
+    DataContainer vsxe_container(std::move(vsxe_raw));
+    if (!vsxe_container.IsGood()) {
+        return false;
+    }
+
+    std::vector<std::vector<u8>> data;
+    if (!vsxe_container.GetIVFCLevel4Data(data)) {
+        return false;
+    }
+
+    return Archive<Extdata>::Init(std::move(data));
+}
+
+bool Extdata::ExtractFile(const std::string& path, std::size_t index) const {
+    /// Maximum amount of device files a device directory can hold.
+    constexpr u32 DeviceDirCapacity = 126;
+
+    FileUtil::IOFile file(path, "wb");
+    if (!file) {
+        LOG_ERROR(Core, "Could not open file {}", path);
+        return false;
+    }
+
+    u32 file_index = index + 1;
+    u32 sub_directory_id = file_index / DeviceDirCapacity;
+    u32 sub_file_id = file_index % DeviceDirCapacity;
+    std::string device_file_path =
+        fmt::format("{}{:08x}/{:08x}", data_path, sub_directory_id, sub_file_id);
+
+    auto container_data = ReadFile(device_file_path);
+    if (container_data.empty()) { // File does not exist?
+        LOG_WARNING(Core, "Ignoring file {}", device_file_path);
+        return true;
+    }
+
+    DataContainer container(std::move(container_data));
+    if (!container.IsGood()) {
+        return false;
+    }
+
+    std::vector<std::vector<u8>> data;
+    if (!container.GetIVFCLevel4Data(data)) {
+        return false;
+    }
+
+    if (file.WriteBytes(data[0].data(), data[0].size()) != data[0].size()) {
+        LOG_ERROR(Core, "Write data failed (file: {})", path);
+        return false;
+    }
+
+    return true;
+}
+
+ArchiveFormatInfo Extdata::GetFormatInfo() const {
+    // This information is based on how Citra created the metadata in FS
+    ArchiveFormatInfo format_info = {/* total_size */ 0,
+                                     /* number_directories */ fs_info.maximum_directory_count,
+                                     /* number_files */ fs_info.maximum_file_count,
+                                     /* duplicate_data */ false};
+
+    return format_info;
+}
+
+} // namespace Core