CommonHostInterface: Add save state backup option

src/duckstation-qt/advancedsettingswidget.cpp

@@ -198,6 +198,9 @@ AdvancedSettingsWidget::AdvancedSettingsWidget(QtHostInterface* host_interface,
   addBooleanTweakOption(m_host_interface, m_ui.tweakOptionTable, tr("Allow Booting Without SBI File"), "CDROM",
                         "AllowBootingWithoutSBIFile", false);
 
+  addBooleanTweakOption(m_host_interface, m_ui.tweakOptionTable, tr("Create Save State Backups"), "General",
+                        "CreateSaveStateBackups", false);
+
   dialog->registerWidgetHelp(m_ui.logLevel, tr("Log Level"), tr("Information"),
                              tr("Sets the verbosity of messages logged. Higher levels will log more messages."));
   dialog->registerWidgetHelp(m_ui.logToConsole, tr("Log To System Console"), tr("User Preference"),
@@ -238,4 +241,5 @@ void AdvancedSettingsWidget::onResetToDefaultClicked()
   setBooleanTweakOption(m_ui.tweakOptionTable, 19, false);
   setBooleanTweakOption(m_ui.tweakOptionTable, 20, true);
   setBooleanTweakOption(m_ui.tweakOptionTable, 21, false);
+  setBooleanTweakOption(m_ui.tweakOptionTable, 22, false);
 }

src/frontend-common/common_host_interface.cpp

@@ -789,6 +789,7 @@ bool CommonHostInterface::SaveState(bool global, s32 slot)
   }
 
   std::string save_path = global ? GetGlobalSaveStateFileName(slot) : GetGameSaveStateFileName(code.c_str(), slot);
+  RenameCurrentSaveStateToBackup(save_path.c_str());
   if (!SaveState(save_path.c_str()))
     return false;
 
@@ -2745,6 +2746,24 @@ std::string CommonHostInterface::GetGlobalSaveStateFileName(s32 slot) const
     return GetUserDirectoryRelativePath("savestates" FS_OSPATH_SEPARATOR_STR "savestate_%d.sav", slot);
 }
 
+void CommonHostInterface::RenameCurrentSaveStateToBackup(const char* filename)
+{
+  if (!GetBoolSettingValue("General", "CreateSaveStateBackups", false))
+    return;
+
+  if (!FileSystem::FileExists(filename))
+    return;
+
+  const std::string backup_filename(FileSystem::ReplaceExtension(filename, "bak"));
+  if (!FileSystem::RenamePath(filename, backup_filename.c_str()))
+  {
+    Log_ErrorPrintf("Failed to rename save state backup '%s'", backup_filename.c_str());
+    return;
+  }
+
+  Log_InfoPrintf("Renamed save state '%s' to '%s'", filename, backup_filename.c_str());
+}
+
 std::vector<CommonHostInterface::SaveStateInfo> CommonHostInterface::GetAvailableSaveStates(const char* game_code) const
 {
   std::vector<SaveStateInfo> si;

src/frontend-common/common_host_interface.h

@@ -404,6 +404,9 @@ protected:
   /// Returns the path to a save state file. Specifying an index of -1 is the "resume" save state.
   std::string GetGlobalSaveStateFileName(s32 slot) const;
 
+  /// Moves the current save state file to a backup name, if it exists.
+  void RenameCurrentSaveStateToBackup(const char* filename);
+
   /// Sets the base path for the user directory. Can be overridden by platform/frontend/command line.
   virtual void SetUserDirectory();
 

src/frontend-common/fullscreen_ui.cpp

@@ -2526,6 +2526,14 @@ void DrawSettingsWindow()
                        &s_settings_copy.increase_timer_resolution);
 #endif
 
+        settings_changed |= ToggleButtonForNonSetting("Allow Booting Without SBI File",
+                                                      "Allows loading protected games without subchannel information.",
+                                                      "CDROM", "AllowBootingWithoutSBIFile", false);
+
+        settings_changed |= ToggleButtonForNonSetting("Create Save State Backups",
+                                                      "Renames existing save states when saving to a backup file.",
+                                                      "General", "CreateSaveStateBackups", false);
+
         MenuHeading("Display Settings");
         settings_changed |= ToggleButtonForNonSetting("Show Status Indicators",
                                                       "Shows persistent icons when turbo is active or when paused.",