Generate instance ID separate from rcon password

Create a random instance ID using Math.random instead of deriving it
from the RCON password with a hombrew hash algorithm.  Remove
stringUtils as it's no longer needed.

CHANGELOG.md

@@ -18,6 +18,8 @@ Version 2.0.0
   privileges requirements of symlinks.
 - Changed the per instance scenario folder to be linked instead of
   copied on instance creation.
+- Instance id is no longer derived from the rcon password, instead it's
+  generated upon instance creation and stored in the instance config.
 
 ### Breaking Changes
 

client.js

@@ -17,7 +17,6 @@ const crypto = require("crypto");
 // internal libraries
 const objectOps = require("lib/objectOps.js");
 const fileOps = require("lib/fileOps");
-const stringUtils = require("lib/stringUtils.js");
 const pluginManager = require("lib/manager/pluginManager");
 const modManager = require("lib/manager/modManager");
 const hashFile = require('lib/hash').hashFile;
@@ -402,6 +401,7 @@ write-data=${ instance.path() }\r\n
 
 	await symlinkMods(instance, "sharedMods", console);
 	let instconf = {
+		"id": Math.random() * 2 ** 31 | 0,
 		"factorioPort": args.port || process.env.FACTORIOPORT || randomDynamicPort(),
 		"clientPort": args["rcon-port"] || process.env.RCONPORT || randomDynamicPort(),
 		"__comment_clientPassword": "This is the rcon password. Its also used for making an instanceID. Make sure its unique and not blank.",
@@ -490,7 +490,12 @@ write-data=${ instance.path() }\r\n
 
 async function startInstance(config, args, instance) {
 	var instanceconfig = JSON.parse(await fs.readFile(instance.path("config.json")));
-	instanceconfig.unique = stringUtils.hashCode(instanceconfig.clientPassword);
+	if (typeof instanceconfig.id !== "number" || isNaN(instanceconfig.id)) {
+		throw new Error(`${instance.path("config.json")} is missing id`);
+	}
+	// Temporary measure for backwards compatibility
+	instanceconfig.unique = instanceconfig.id;
+
 	if (process.env.FACTORIOPORT) {
 		instanceconfig.factorioPort = process.env.FACTORIOPORT;
 	}

lib/stringUtils.js

@@ -1,13 +0,0 @@
-function hashCode(string){
-	if(typeof string !== "string") throw "ERROR stringUtils: Not a string";
-	var hash = 0;
-	if (string.length == 0) return hash;
-	for (let i = 0; i < string.length; i++) {
-		hash = ((hash << 5) - hash) + string.charCodeAt(i);
-		hash = hash & hash; // Convert to 32bit integer
-	}
-	return hash;
-}
-module.exports = {
-	hashCode: hashCode,
-}

sharedPlugins/clusterioMod/index.js

@@ -3,7 +3,6 @@ const fs = require("fs-extra");
 
 const objectOps = require("lib/objectOps.js");
 const fileOps = require("lib/fileOps");
-const stringUtils = require("lib/stringUtils.js");
 const checkHotpatchInstallation = require("lib/clusterTools/checkHotpatchInstallation");
 const getLua = require("lib/clusterTools/getLua");
 

test/lib/stringUtils.js

@@ -1,48 +0,0 @@
-const assert = require("assert");
-const stringUtils = require("lib/stringUtils");
-
-describe("stringUtils.js", function(){
-	describe("hashCode", function(){
-		it("Produces a 32bit signed int hash from a string", function(){
-			let x = stringUtils.hashCode("whatever");
-			let y = stringUtils.hashCode(" a much longer string to prove this works for long strings as well and also special characters &!¤(#)¤");
-			
-			assert(typeof x == "number", "hashCode should be returning a 32 bit signed int");
-			assert(x.toString() == "1934383586");
-			assert(y.toString() == "1648886132");
-		});
-		let permutations = 1000;
-		it("Rarely produces same hash for different strings ("+permutations+" hashes with collision check)", function(){
-			let keyHashPairs = [];
-			for(let i = 0; i < permutations; i++){
-				let string = Math.random().toString();
-				keyHashPairs.push({
-					key:string,
-					hash:stringUtils.hashCode(string),
-				});
-			}
-			
-			for(let i = 0; i < permutations; i++){
-				for(let o = 0; o < permutations; o++){
-					assert(i == o || keyHashPairs[o].key != keyHashPairs[i].key, "Woha, Math.random() generated 2 equal numbers???");
-					assert(i == o || keyHashPairs[o].hash != keyHashPairs[i].hash, "Hash collision, as long at it doesn't happen again its fine.");
-				}
-			}
-		});
-		it("Returns 0 for 0 length strings", function(){
-			let x = stringUtils.hashCode("");
-			assert.deepEqual(x, 0);
-		});
-		it("Throws when supplied with anything other than a string", function(){
-			assert.throws(function(){
-				stringUtils.hashCode([]);
-			}, "ERROR: Not a string")
-			assert.throws(function(){
-				stringUtils.hashCode({});
-			}, "ERROR: Not a string")
-			assert.throws(function(){
-				stringUtils.hashCode(0);
-			}, "ERROR: Not a string")
-		});
-	});
-});