Add option to disable save patching

Add factorio.enable_save_patching config entry to allow disabling the
save patching done on startup.  This is for running vannila games or
scenarios that are not compatible with Clusterio.

docs/how-it-works.md

@@ -9,6 +9,10 @@ based on the built in
 library to Factorio and requires scenarios to be coded specifically for
 it.  Mods on the other hand work without modifications.
 
+This can be disabled with the `factorio.enable_save_patching` config on
+a per instance basis, however disabling it means that modules are not
+loaded into the game and most plugins will not function.
+
 <sub>1: Before version 2.0 of Clusterio this was done at runtime
 with a patcher called Hotpatch, but due to the difficulty in supporting
 run time patching and the lack of documentation it was replace it with

docs/writing-plugins.md

@@ -195,6 +195,20 @@ where appropriate.  See [Configuration System](configuration-system.md)
 for more details on how this system works.
 
 
+### Handling Invalid Configuration
+
+If the plugin requires a certain feature to be enabled to function it
+should throw an error during init if this is not the case.  The most
+common such feature is the save patching, which can be disabled to run
+vanilla or scenarios not compatible with Clusterio.  For example:
+
+    async init() {
+        if (!this.instance.config.get("factorio.enable_save_patching")) {
+            throw new Error("foo_frobber plugin requires save patching.");
+        }
+    }
+
+
 Communicating with Factorio
 ---------------------------
 

lib/config/definitions.js

@@ -239,6 +239,12 @@ FactorioGroup.define({
 	type: "string",
 	optional: true,
 });
+FactorioGroup.define({
+	name: "enable_save_patching",
+	description: "Patch saves with Lua code. Required for Clusterio integrations, lua modules, and most plugins.",
+	type: "boolean",
+	initial_value: true,
+});
 FactorioGroup.define({
 	name: "settings",
 	description: "Settings overridden in server-settings.json",

plugins/research_sync/instance.js

@@ -13,6 +13,10 @@ function unexpectedError(err) {
 
 class InstancePlugin extends plugin.BaseInstancePlugin {
 	async init() {
+		if (!this.instance.config.get("factorio.enable_save_patching")) {
+			throw new Error("research_sync plugin requires save patching.");
+		}
+
 		this.instance.server.on("ipc-research_sync:contribution", (tech) => {
 			this.researchContribution(tech).catch(unexpectedError);
 		});

plugins/statistics_exporter/instance.js

@@ -22,6 +22,12 @@ const instanceGameFlowStatistics = new Gauge(
 
 
 class InstancePlugin extends plugin.BaseInstancePlugin {
+	async init() {
+		if (!this.instance.config.get("factorio.enable_save_patching")) {
+			throw new Error("statistics_exporter plugin requires save patching.");
+		}
+	}
+
 	async onMetrics() {
 		let string = await this.instance.server.sendRcon("/sc statistics_exporter.export()");
 		let stats;

slave.js

@@ -330,6 +330,10 @@ class Instance extends link.Link{
 			saveName = "world.zip";
 		}
 
+		if (!this.config.get("factorio.enable_save_patching")) {
+			return saveName;
+		}
+
 		// Patch save with lua modules from plugins
 		console.log("Clusterio | Patching save");
 
@@ -409,8 +413,11 @@ class Instance extends link.Link{
 
 		this.server.on("exit", () => this.notifyExit());
 		await this.server.start(saveName);
-		await this.server.disableAchievements();
-		await this.updateInstanceData();
+
+		if (this.config.get("factorio.enable_save_patching")) {
+			await this.server.disableAchievements();
+			await this.updateInstanceData();
+		}
 
 		await plugin.invokeHook(this.plugins, "onStart");