Function DoSave

src/saveload/saveload.cpp:3046–3070

* Actually perform the saving of the savegame. * General tactics is to first save the game to memory, then write it to file * using the writer, either in threaded mode if possible, or single-threaded. * @param writer The filter to write the savegame to. * @param threaded Whether to try to perform the saving asynchronously. * @return Return the result of the action. #SL_OK or #SL_ERROR */

 * @return Return the result of the action. #SL_OK or #SL_ERROR
 */
static SaveOrLoadResult DoSave(std::shared_ptr<SaveFilter> writer, bool threaded)
{
	assert(!_sl.saveinprogress);

	_sl.dumper = std::make_unique<MemoryDumper>();
	_sl.sf = std::move(writer);

	_sl_version = SAVEGAME_VERSION;

	SaveViewportBeforeSaveGame();
	SlSaveChunks();

	SaveFileStart();

	if (!threaded || !StartNewThread(&_save_thread, "ottd:savegame", &SaveFileToDisk, true)) {
		if (threaded) Debug(sl, 1, "Cannot create savegame thread, reverting to single-threaded mode...");

		SaveOrLoadResult result = SaveFileToDisk(false);
		SaveFileDone();

		return result;
	}

	return SL_OK;
}

/**
 * Save the game using a (writer) filter.