116 lines
3.3 KiB
JavaScript
116 lines
3.3 KiB
JavaScript
// @ts-ignore
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import DhtNode from "@hyperswarm/dht-relay";
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// @ts-ignore
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import Stream from "@hyperswarm/dht-relay/ws";
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// @ts-ignore
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import createRoundRobin from "@derhuerst/round-robin-scheduler";
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// @ts-ignore
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import { Buffer } from "buffer";
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// @ts-ignore
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import { blake2b } from "libskynet";
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// @ts-ignore
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import { registryRead } from "libkmodule";
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import { unpack } from "msgpackr";
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const REGISTRY_DHT_KEY = "lumeweb-dht-node";
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export default class DHT {
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_wsPool;
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_options;
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_relays = {};
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constructor(opts = {}) {
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// @ts-ignore
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opts.custodial = true;
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this._options = opts;
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this._wsPool = createRoundRobin();
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}
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ready() {
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return Promise.resolve();
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}
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get relays() {
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return Object.keys(this._relays);
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}
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async addRelay(pubkey) {
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let entry = await registryRead(Uint8Array.from(Buffer.from(pubkey, "hex")), hashDataKey(REGISTRY_DHT_KEY));
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if (entry[1] || !entry[0]?.exists) {
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return false;
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}
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let host;
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try {
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host = unpack(entry[0].entryData);
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}
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catch (e) {
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return false;
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}
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const [domain, port] = host.split(":");
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if (isNaN(parseInt(port))) {
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return false;
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}
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const connection = `wss://${domain}:${port}/`;
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this._wsPool.add(connection);
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this._relays[pubkey] = connection;
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return true;
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}
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removeRelay(pubkey) {
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if (!(pubkey in this._relays)) {
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return false;
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}
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this._wsPool.remove(this._relays[pubkey]);
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delete this._relays[pubkey];
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return true;
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}
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clearRelays() {
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this._wsPool = createRoundRobin();
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this._relays = {};
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}
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async isServerAvailable(connection) {
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return new Promise((resolve) => {
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const ws = new WebSocket(connection);
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ws.addEventListener("open", () => {
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ws.close();
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resolve(true);
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});
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ws.addEventListener("error", () => {
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resolve(false);
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});
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});
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}
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async connect(pubkey, options = {}) {
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const relay = await this.getAvailableRelay();
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if (!relay) {
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throw new Error("Failed to find an available relay");
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}
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const node = new DhtNode(new Stream(true, new WebSocket(relay)), this._options);
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await node.ready();
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return node.connect(pubkey, options);
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}
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async getAvailableRelay() {
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for (let i = 0; i < this._wsPool.length; i++) {
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const relay = this._wsPool.get();
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if (await this.isServerAvailable(relay)) {
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return relay;
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}
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}
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return false;
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}
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}
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export function hashDataKey(dataKey) {
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return blake2b(encodeUtf8String(dataKey));
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}
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function encodeUtf8String(str) {
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const byteArray = stringToUint8ArrayUtf8(str);
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const encoded = new Uint8Array(8 + byteArray.length);
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encoded.set(encodeNumber(byteArray.length));
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encoded.set(byteArray, 8);
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return encoded;
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}
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function stringToUint8ArrayUtf8(str) {
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return Uint8Array.from(Buffer.from(str, "utf-8"));
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}
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function encodeNumber(num) {
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const encoded = new Uint8Array(8);
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for (let index = 0; index < encoded.length; index++) {
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encoded[index] = num & 0xff;
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num = num >> 8;
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}
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return encoded;
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}
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