Codechange: split off the settings saveload code from the main settings handling logic

2 files changed, 179 insertions, 0 deletions

diff --git a/src/saveload/CMakeLists.txt b/src/saveload/CMakeLists.txt
index 5f83309a4..32bcc57ac 100644
--- a/src/saveload/CMakeLists.txt
+++ b/src/saveload/CMakeLists.txt
@@ -33,6 +33,7 @@ add_files(
     saveload.h
     saveload_filter.h
     saveload_internal.h
+    settings_sl.cpp
     signs_sl.cpp
     station_sl.cpp
     storage_sl.cpp
diff --git a/src/saveload/settings_sl.cpp b/src/saveload/settings_sl.cpp
new file mode 100644
index 000000000..2097d8645
--- /dev/null
+++ b/src/saveload/settings_sl.cpp
@@ -0,0 +1,178 @@
+/*
+ * This file is part of OpenTTD.
+ * OpenTTD is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, version 2.
+ * OpenTTD is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
+ * See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with OpenTTD. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+/** @file settings_sl.cpp Handles the saveload part of the settings. */
+
+#include "../stdafx.h"
+
+#include "saveload.h"
+#include "compat/settings_sl_compat.h"
+
+#include "../settings_type.h"
+#include "../settings_table.h"
+#include "../network/network.h"
+#include "../fios.h"
+
+#include "../safeguards.h"
+
+/**
+ * Prepare for reading and old diff_custom by zero-ing the memory.
+ */
+void PrepareOldDiffCustom()
+{
+	memset(_old_diff_custom, 0, sizeof(_old_diff_custom));
+}
+
+/**
+ * Reading of the old diff_custom array and transforming it to the new format.
+ * @param savegame is it read from the config or savegame. In the latter case
+ *                 we are sure there is an array; in the former case we have
+ *                 to check that.
+ */
+void HandleOldDiffCustom(bool savegame)
+{
+	/* Savegames before v4 didn't have "town_council_tolerance" in savegame yet. */
+	bool has_no_town_council_tolerance = savegame && IsSavegameVersionBefore(SLV_4);
+	uint options_to_load = GAME_DIFFICULTY_NUM - (has_no_town_council_tolerance ? 1 : 0);
+
+	if (!savegame) {
+		/* If we did read to old_diff_custom, then at least one value must be non 0. */
+		bool old_diff_custom_used = false;
+		for (uint i = 0; i < options_to_load && !old_diff_custom_used; i++) {
+			old_diff_custom_used = (_old_diff_custom[i] != 0);
+		}
+
+		if (!old_diff_custom_used) return;
+	}
+
+	/* Iterate over all the old difficulty settings, and convert the list-value to the new setting. */
+	uint i = 0;
+	for (const auto &name : _old_diff_settings) {
+		if (has_no_town_council_tolerance && name == "town_council_tolerance") continue;
+
+		std::string fullname = "difficulty." + name;
+		const SettingDesc *sd = GetSettingFromName(fullname);
+
+		/* Some settings are no longer in use; skip reading those. */
+		if (sd == nullptr) {
+			i++;
+			continue;
+		}
+
+		int32 value = (int32)((name == "max_loan" ? 1000 : 1) * _old_diff_custom[i++]);
+		sd->AsIntSetting()->MakeValueValidAndWrite(savegame ? &_settings_game : &_settings_newgame, value);
+	}
+}
+
+/**
+ * Get the SaveLoad description for the SettingTable.
+ * @param settings SettingDesc struct containing all information.
+ * @param is_loading True iff the SaveLoad table is for loading.
+ * @return Vector with SaveLoad entries for the SettingTable.
+ */
+static std::vector<SaveLoad> GetSettingsDesc(const SettingTable &settings, bool is_loading)
+{
+	std::vector<SaveLoad> saveloads;
+	for (auto &desc : settings) {
+		const SettingDesc *sd = GetSettingDesc(desc);
+		if (sd->flags & SF_NOT_IN_SAVE) continue;
+
+		if (is_loading && (sd->flags & SF_NO_NETWORK_SYNC) && _networking && !_network_server) {
+			if (IsSavegameVersionBefore(SLV_TABLE_CHUNKS)) {
+				/* We don't want to read this setting, so we do need to skip over it. */
+				saveloads.push_back({sd->name, sd->save.cmd, GetVarFileType(sd->save.conv) | SLE_VAR_NULL, sd->save.length, sd->save.version_from, sd->save.version_to, 0, nullptr, 0, nullptr});
+			}
+			continue;
+		}
+
+		SaveLoad sv = sd->save;
+		/* Replace the name with the actual name of the setting. */
+		if (!sd->name.empty()) sv.name = sd->name;
+		saveloads.push_back(sv);
+	}
+
+	return saveloads;
+}
+
+/**
+ * Save and load handler for settings
+ * @param settings SettingDesc struct containing all information
+ * @param object can be either nullptr in which case we load global variables or
+ * a pointer to a struct which is getting saved
+ */
+static void LoadSettings(const SettingTable &settings, void *object, const SaveLoadCompatTable &slct)
+{
+	const std::vector<SaveLoad> slt = SlCompatTableHeader(GetSettingsDesc(settings, true), slct);
+
+	if (!IsSavegameVersionBefore(SLV_RIFF_TO_ARRAY) && SlIterateArray() == -1) return;
+	SlObject(object, slt);
+	if (!IsSavegameVersionBefore(SLV_RIFF_TO_ARRAY) && SlIterateArray() != -1) SlErrorCorrupt("Too many settings entries");
+
+	/* Ensure all IntSettings are valid (min/max could have changed between versions etc). */
+	for (auto &desc : settings) {
+		const SettingDesc *sd = GetSettingDesc(desc);
+		if (sd->flags & SF_NOT_IN_SAVE) continue;
+		if ((sd->flags & SF_NO_NETWORK_SYNC) && _networking && !_network_server) continue;
+		if (!SlIsObjectCurrentlyValid(sd->save.version_from, sd->save.version_to)) continue;
+
+		if (sd->IsIntSetting()) {
+			const IntSettingDesc *int_setting = sd->AsIntSetting();
+			int_setting->MakeValueValidAndWrite(object, int_setting->Read(object));
+		}
+	}
+}
+
+/**
+ * Save and load handler for settings
+ * @param settings SettingDesc struct containing all information
+ * @param object can be either nullptr in which case we load global variables or
+ * a pointer to a struct which is getting saved
+ */
+static void SaveSettings(const SettingTable &settings, void *object)
+{
+	const std::vector<SaveLoad> slt = GetSettingsDesc(settings, false);
+
+	SlTableHeader(slt);
+
+	SlSetArrayIndex(0);
+	SlObject(object, slt);
+}
+
+static void Load_OPTS()
+{
+	/* Copy over default setting since some might not get loaded in
+	 * a networking environment. This ensures for example that the local
+	 * autosave-frequency stays when joining a network-server */
+	PrepareOldDiffCustom();
+	LoadSettings(_gameopt_settings, &_settings_game, _gameopt_sl_compat);
+	HandleOldDiffCustom(true);
+}
+
+static void Load_PATS()
+{
+	/* Copy over default setting since some might not get loaded in
+	 * a networking environment. This ensures for example that the local
+	 * currency setting stays when joining a network-server */
+	LoadSettings(_settings, &_settings_game, _settings_sl_compat);
+}
+
+static void Check_PATS()
+{
+	LoadSettings(_settings, &_load_check_data.settings, _settings_sl_compat);
+}
+
+static void Save_PATS()
+{
+	SaveSettings(_settings, &_settings_game);
+}
+
+static const ChunkHandler setting_chunk_handlers[] = {
+	{ 'OPTS', nullptr,   Load_OPTS, nullptr, nullptr,    CH_READONLY  },
+	{ 'PATS', Save_PATS, Load_PATS, nullptr, Check_PATS, CH_TABLE },
+};
+
+extern const ChunkHandlerTable _setting_chunk_handlers(setting_chunk_handlers);