Implement basic proxy to connect to stopped instances

packages/controller/src/PlayerRoutingStore.ts

@@ -0,0 +1,75 @@
+import fs from "node:fs/promises";
+
+import * as lib from "@clusterio/lib";
+
+export type StoredRoute = {
+	name: string;
+	instanceId: number;
+	hostId: number;
+	gamePort: number;
+	timestampMs: number;
+};
+
+export default class PlayerRoutingStore {
+	private _routes = new Map<string, StoredRoute>();
+	private _dirty = false;
+
+	constructor(private _filePath: string) {}
+
+	get(name: string): StoredRoute | undefined {
+		return this._routes.get(name.toLowerCase());
+	}
+
+	update(name: string, instanceId: number, hostId: number, gamePort: number, timestampMs: number) {
+		const key = name.toLowerCase();
+		this._routes.set(key, { name, instanceId, hostId, gamePort, timestampMs });
+		this._dirty = true;
+	}
+
+	delete(name: string) {
+		const key = name.toLowerCase();
+		if (this._routes.delete(key)) {
+			this._dirty = true;
+		}
+	}
+
+	dropHost(hostId: number) {
+		let removed = false;
+		for (const [key, route] of this._routes) {
+			if (route.hostId === hostId) {
+				this._routes.delete(key);
+				removed = true;
+			}
+		}
+		if (removed) {
+			this._dirty = true;
+		}
+	}
+
+	async load(): Promise<void> {
+		try {
+			const routes = JSON.parse(await fs.readFile(this._filePath, { encoding: "utf8" })) as StoredRoute[];
+			this._routes.clear();
+			for (const route of routes) {
+				if (!route || !route.name) {
+					continue;
+				}
+				this._routes.set(route.name.toLowerCase(), route);
+			}
+			this._dirty = false;
+		} catch (err: any) {
+			if (err.code !== "ENOENT") {
+				throw err;
+			}
+		}
+	}
+
+	async save(): Promise<void> {
+		if (!this._dirty) {
+			return;
+		}
+		const payload = JSON.stringify([...this._routes.values()], null, "\t");
+		await lib.safeOutputFile(this._filePath, payload);
+		this._dirty = false;
+	}
+}