85 lines
2.1 KiB
TypeScript
85 lines
2.1 KiB
TypeScript
import type { ServerWebSocket } from "bun";
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import * as Y from "yjs";
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import { encode } from "./protocol";
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export interface Client {
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ws: ServerWebSocket<{ room: string | null }>;
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}
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export class Session {
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doc: Y.Doc;
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clients: Set<Client> = new Set();
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constructor(public name: string) {
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this.doc = new Y.Doc();
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}
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join(client: Client) {
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this.clients.add(client);
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// send full state to new client
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const state = Y.encodeStateAsUpdate(this.doc);
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client.ws.send(encode({ type: "sync", data: Array.from(state) }));
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this.broadcastPeerCount();
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}
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leave(client: Client) {
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this.clients.delete(client);
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this.broadcastPeerCount();
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}
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isEmpty(): boolean {
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return this.clients.size === 0;
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}
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applyUpdate(update: Uint8Array, from: Client) {
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try {
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Y.applyUpdate(this.doc, update);
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// broadcast to others
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for (const client of this.clients) {
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if (client !== from) {
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client.ws.send(encode({ type: "update", data: Array.from(update) }));
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}
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}
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} catch (err) {
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console.error(`failed to apply update in session ${this.name}:`, err);
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// optionally notify the client that sent the bad update
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try {
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from.ws.send(encode({ type: "error", message: "invalid update" }));
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} catch {
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// ignore send errors
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}
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}
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}
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broadcastPeerCount() {
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const msg = encode({ type: "peers", count: this.clients.size });
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for (const client of this.clients) {
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client.ws.send(msg);
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}
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}
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}
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// room name -> session
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const sessions = new Map<string, Session>();
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export function getOrCreateSession(name: string): Session {
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let session = sessions.get(name);
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if (!session) {
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session = new Session(name);
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sessions.set(name, session);
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console.debug(`session created: ${name}`);
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}
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return session;
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}
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export function getSession(name: string): Session | undefined {
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return sessions.get(name);
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}
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export function removeSession(name: string): void {
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const session = sessions.get(name);
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if (session?.isEmpty()) {
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sessions.delete(name);
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console.debug(`session removed: ${name}`);
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}
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}
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