import { Actor } from './actor.js'; import { Action } from './action.js'; import { Message, PostMessage, PeerMessage } from './message.js'; import { CryptoUtil } from './crypto.js'; import { ForumView } from './forum-view.js'; import { PrioritizedQueue } from './prioritized-queue.js'; export class ForumNode extends Actor { constructor(name, scene) { super(name, scene); this.forumView = new ForumView(); this.queue = new PrioritizedQueue(); this.actions = { storePost: new Action('store post', scene), peerMessage: new Action('peer message', scene), }; } // Generate a signing key pair and connect to the network async initialize(forumNetwork) { this.keyPair = await CryptoUtil.generateAsymmetricKey(); this.forumNetwork = forumNetwork.addNode(this); this.status.set('Initialized'); return this; } // Send a message to all other nodes in the network async broadcast(message) { await message.sign(this.keyPair); const otherForumNodes = this.forumNetwork .listNodes() .filter((forumNode) => forumNode.keyPair.publicKey !== this.keyPair.publicKey); for (const forumNode of otherForumNodes) { // For now just call receiveMessage on the target node this.actions.peerMessage.log(this, forumNode, null, message.content); await forumNode.receiveMessage(JSON.stringify(message.toJSON())); } } // Perform minimal processing to ingest a message. // Enqueue it for further processing. async receiveMessage(messageStr) { const messageJson = JSON.parse(messageStr); const senderReputation = this.forumView.getReputation(messageJson.publicKey) || 0; this.queue.add(messageJson, senderReputation); } // Process next highest priority message in the queue async processNextMessage() { const messageJson = this.queue.pop(); if (!messageJson) { return null; } await this.processMessage(messageJson); } // Process a message from the queue async processMessage(messageJson) { try { await Message.verify(messageJson); } catch (e) { this.actions.processMessage.log(this, this, 'invalid signature', messageJson, '-x'); console.log(`${this.name}: received message with invalid signature`); return; } const { publicKey } = messageJson; const message = Message.fromJSON(messageJson); console.log(`${this.name}: processMessage`, message); if (message instanceof PostMessage) { await this.processPostMessage(publicKey, message.content); } else if (message instanceof PeerMessage) { await this.processPeerMessage(publicKey, message.content); } else { // Unknown message type // Penalize sender for wasting our time console.log(`${this.name}: penalizing sender for unknown message type ${message.type}`); this.forumView.incrementReputation(message.publicKey, -1); } } // Process an incoming post, received by whatever means processPost(authorId, post, stake) { this.actions.storePost.log(this, this, null, { authorId, post, stake }); this.forumView.addPost(authorId, post.id, post, stake); } // Process a post we received in a message async processPostMessage(authorId, { post, stake }) { this.processPost(authorId, post, stake); await this.broadcast( new PeerMessage({ posts: [{ authorId, post, stake }], }), ); } // Process a message we receive from a peer async processPeerMessage(peerId, { posts }) { // We are trusting that the peer verified the signatures of the posts they're forwarding. // We could instead have the peer forward the signed messages and re-verify them. for (const { authorId, post, stake } of posts) { this.processPost(authorId, post, stake); } } }