MemoryCardImage: Implement save file importing and exporting

src/core/memory_card_image.cpp

@@ -466,4 +466,95 @@ bool ImportCard(DataArray* data, const char* filename)
   }
 }
 
-} // namespace MemoryCardImage
+bool ExportSave(DataArray* data, const FileInfo& fi, const char* filename)
+{
+  std::unique_ptr<ByteStream> stream =
+    FileSystem::OpenFile(filename, BYTESTREAM_OPEN_CREATE | BYTESTREAM_OPEN_TRUNCATE | BYTESTREAM_OPEN_WRITE |
+                                     BYTESTREAM_OPEN_ATOMIC_UPDATE | BYTESTREAM_OPEN_STREAMED);
+  if (!stream)
+  {
+    Log_ErrorPrintf("Failed to open '%s' for writing.", filename);
+    return false;
+  }
+
+  DirectoryFrame* df_ptr = GetFramePtr<DirectoryFrame>(data, 0, fi.first_block);
+  std::vector<u8> header = std::vector<u8>(static_cast<size_t>(FRAME_SIZE));
+  std::memcpy(header.data(), df_ptr, sizeof(*df_ptr));
+
+  std::vector<u8> blocks;
+  if (!ReadFile(*data, fi, &blocks))
+  {
+    Log_ErrorPrintf("Failed to read save blocks from memory card data");
+    return false;
+  }
+
+  if (!stream->Write(header.data(), static_cast<u32>(header.size())) ||
+      !stream->Write(blocks.data(), static_cast<u32>(blocks.size())) || !stream->Commit())
+  {
+    Log_ErrorPrintf("Failed to write exported save to '%s'", filename);
+    stream->Discard();
+    return false;
+  }
+
+  return true;
+}
+
+bool ImportSave(DataArray* data, const char* filename)
+{
+  FILESYSTEM_STAT_DATA sd;
+  if (!FileSystem::StatFile(filename, &sd))
+  {
+    Log_ErrorPrintf("Failed to stat file '%s'", filename);
+    return false;
+  }
+
+  // Make sure the size of the actual file is valid
+  if (sd.Size <= FRAME_SIZE || (sd.Size - FRAME_SIZE) % BLOCK_SIZE != 0u || (sd.Size - FRAME_SIZE) / BLOCK_SIZE > 15u)
+  {
+    Log_ErrorPrintf("Invalid size for save file '%s'", filename);
+    return false;
+  }
+
+  std::unique_ptr<ByteStream> stream = FileSystem::OpenFile(filename, BYTESTREAM_OPEN_READ | BYTESTREAM_OPEN_STREAMED);
+  if (!stream)
+  {
+    Log_ErrorPrintf("Failed to open '%s' for reading", filename);
+    return false;
+  }
+
+  DirectoryFrame df;
+  if (stream->Read(&df, FRAME_SIZE) != FRAME_SIZE)
+  {
+    Log_ErrorPrintf("Failed to read directory frame from '%s'", filename);
+    return false;
+  }
+
+  // Make sure the size reported by the directory frame is valid
+  if (df.file_size < BLOCK_SIZE || df.file_size % BLOCK_SIZE != 0 || df.file_size / BLOCK_SIZE > 15u)
+  {
+    Log_ErrorPrintf("Invalid size (%u bytes) reported by directory frame", df.file_size);
+    return false;
+  }
+
+  // Make sure there isn't already a save with the same name
+  std::vector<FileInfo> fileinfos = EnumerateFiles(*data);
+  for (const FileInfo& fi : fileinfos)
+  {
+    if (fi.filename.compare(0, sizeof(df.filename), df.filename) == 0)
+    {
+      Log_ErrorPrintf("Save file with the same name already exists in memory card");
+      return false;
+    }
+  }
+
+  std::vector<u8> blocks = std::vector<u8>(static_cast<size_t>(df.file_size));
+  if (stream->Read(blocks.data(), df.file_size) != df.file_size)
+  {
+    Log_ErrorPrintf("Failed to read block bytes from '%s'", filename);
+    return false;
+  }
+
+  return WriteFile(data, df.filename, blocks);
+}
+
+} // namespace MemoryCardImage

src/core/memory_card_image.h

@@ -7,8 +7,7 @@
 #include <string_view>
 #include <vector>
 
-namespace MemoryCardImage
-{
+namespace MemoryCardImage {
 enum : u32
 {
   DATA_SIZE = 128 * 1024, // 1mbit
@@ -17,7 +16,7 @@ enum : u32
   FRAMES_PER_BLOCK = BLOCK_SIZE / FRAME_SIZE,
   NUM_BLOCKS = DATA_SIZE / BLOCK_SIZE,
   NUM_FRAMES = DATA_SIZE / FRAME_SIZE,
-  ICON_WIDTH =16,
+  ICON_WIDTH = 16,
   ICON_HEIGHT = 16
 };
 
@@ -50,4 +49,6 @@ bool ReadFile(const DataArray& data, const FileInfo& fi, std::vector<u8>* buffer
 bool WriteFile(DataArray* data, const std::string_view& filename, const std::vector<u8>& buffer);
 bool DeleteFile(DataArray* data, const FileInfo& fi);
 bool ImportCard(DataArray* data, const char* filename);
-}
+bool ExportSave(DataArray* data, const FileInfo& fi, const char* filename);
+bool ImportSave(DataArray* data, const char* filename);
+} // namespace MemoryCardImage

src/duckstation-qt/memorycardeditordialog.cpp

@@ -11,6 +11,7 @@ static constexpr char MEMORY_CARD_IMAGE_FILTER[] =
   QT_TRANSLATE_NOOP("MemoryCardEditorDialog", "All Memory Card Types (*.mcd *.mcr *.mc)");
 static constexpr char MEMORY_CARD_IMPORT_FILTER[] =
   QT_TRANSLATE_NOOP("MemoryCardEditorDialog", "All Importable Memory Card Types (*.mcd *.mcr *.mc *.gme)");
+static constexpr char SINGLE_SAVEFILE_FILTER[] = TRANSLATABLE("MemoryCardEditorDialog", "Single Save Files (*.mcs)");
 
 MemoryCardEditorDialog::MemoryCardEditorDialog(QWidget* parent) : QDialog(parent)
 {
@@ -85,6 +86,9 @@ void MemoryCardEditorDialog::connectUi()
   connect(m_ui.saveCardB, &QPushButton::clicked, [this]() { saveCard(&m_card_b); });
   connect(m_ui.importCardA, &QPushButton::clicked, [this]() { importCard(&m_card_a); });
   connect(m_ui.importCardB, &QPushButton::clicked, [this]() { importCard(&m_card_b); });
+  connect(m_ui.exportFile, &QPushButton::clicked, this, &MemoryCardEditorDialog::doExportSaveFile);
+  connect(m_ui.importFileToCardA, &QPushButton::clicked, [this]() { importSaveFile(&m_card_a); });
+  connect(m_ui.importFileToCardB, &QPushButton::clicked, [this]() { importSaveFile(&m_card_b); });
 }
 
 void MemoryCardEditorDialog::populateComboBox(QComboBox* cb)
@@ -377,6 +381,27 @@ void MemoryCardEditorDialog::doDeleteFile()
   updateButtonState();
 }
 
+void MemoryCardEditorDialog::doExportSaveFile()
+{
+  QString filename = QDir::toNativeSeparators(
+    QFileDialog::getSaveFileName(this, tr("Select Single Savefile"), QString(), tr(SINGLE_SAVEFILE_FILTER)));
+
+  if (filename.isEmpty())
+    return;
+
+  const auto [card, fi] = getSelectedFile();
+  if (!fi)
+    return;
+
+  if (!MemoryCardImage::ExportSave(&card->data, *fi, filename.toStdString().c_str()))
+  {
+    QMessageBox::critical(
+      this, tr("Error"),
+      tr("Failed to export save file %1. Check the log for more details.").arg(QString::fromStdString(fi->filename)));
+    return;
+  }
+}
+
 void MemoryCardEditorDialog::importCard(Card* card)
 {
   promptForSave(card);
@@ -402,6 +427,27 @@ void MemoryCardEditorDialog::importCard(Card* card)
   updateButtonState();
 }
 
+void MemoryCardEditorDialog::importSaveFile(Card* card)
+{
+  QString filename =
+    QFileDialog::getOpenFileName(this, tr("Select Import Save File"), QString(), tr(SINGLE_SAVEFILE_FILTER));
+
+  if (filename.isEmpty())
+    return;
+
+  if (!MemoryCardImage::ImportSave(&card->data, filename.toStdString().c_str()))
+  {
+    QMessageBox::critical(this, tr("Error"),
+                          tr("Failed to import save. Check if there is enough room on the memory card or if an "
+                             "existing save with the same name already exists."));
+    return;
+  }
+
+  updateCardTable(card);
+  updateCardBlocksFree(card);
+  setCardDirty(card);
+}
+
 std::tuple<MemoryCardEditorDialog::Card*, const MemoryCardImage::FileInfo*> MemoryCardEditorDialog::getSelectedFile()
 {
   QList<QTableWidgetSelectionRange> sel = m_card_a.table->selectedRanges();

src/duckstation-qt/memorycardeditordialog.h

@@ -57,6 +57,9 @@ private:
   void promptForSave(Card* card);
   void importCard(Card* card);
 
+  void doExportSaveFile();
+  void importSaveFile(Card* card);
+
   std::tuple<Card*, const MemoryCardImage::FileInfo*> getSelectedFile();
   void updateButtonState();