hyperswarm-web/src/index.ts

146 lines
3.5 KiB
TypeScript

// @ts-ignore
import { DhtNode } from "@hyperswarm/dht-relay";
// @ts-ignore
import Stream from "@hyperswarm/dht-relay/ws";
// @ts-ignore
import createPool from "websocket-pool";
// @ts-ignore
import createRoundRobin from "@derhuerst/round-robin-scheduler";
import { Buffer } from "buffer";
import { blake2b } from "libskynet";
import { registryRead } from "libkernel";
import { errTuple } from "libskynet";
const REGISTRY_DHT_KEY = "lumeweb-dht-relay";
const IP_REGEX =
/^(?:(?:2[0-4]\d|25[0-5]|1\d{2}|[1-9]?\d)\.){3}(?:2[0-4]\d|25[0-5]|1\d{2}|[1-9]?\d)$/;
export default class DHT {
private _dht: DhtNode;
private _wsPool: DhtNode;
constructor() {
this._wsPool = createPool(WebSocket, createRoundRobin);
this._dht = new DhtNode(new Stream(true, this._wsPool));
return this.setupProxy();
}
static get IS_WEB() {
return true;
}
private _relays: { [pubkey: string]: () => void } = {};
get relays(): string[] {
return Object.keys(this._relays);
}
public async addRelay(pubkey: string): Promise<boolean> {
let entry: errTuple = await registryRead(
stringToUint8ArrayUtf8(pubkey),
hashDataKey(REGISTRY_DHT_KEY)
);
if (entry[1] || !entry[0]?.exists) {
return false;
}
const host = Buffer.from(entry[0].entryData).toString("utf8") as string;
const [ip, port] = host.split(".");
if (!IP_REGEX.test(ip)) {
return false;
}
if (isNaN(parseInt(port))) {
return false;
}
const connection = `ws://${ip}:${port}/`;
if (!(await this.isServerAvailable(connection))) {
return false;
}
this._relays[pubkey] = this._wsPool.add(connection);
return true;
}
public removeRelay(pubkey: string): boolean {
if (!(pubkey in this._relays)) {
return false;
}
this._relays[pubkey]();
delete this._relays[pubkey];
return true;
}
public clearRelays(): void {
this._wsPool.close();
this._relays = {};
}
private async isServerAvailable(connection: string): Promise<boolean> {
return new Promise((resolve) => {
const ws = new WebSocket(connection);
ws.addEventListener("open", () => {
ws.close();
resolve(true);
});
ws.addEventListener("error", () => {
resolve(false);
});
});
}
private setupProxy() {
return new Proxy(this, {
get(target, name: string) {
if (!target.hasOwnProperty(name)) {
if (!target._dht.hasOwnProperty(name)) {
throw new Error(`Cannot access the ${name} property`);
}
return target._dht[target];
} else {
// @ts-ignore
return target[name];
}
},
has(target, name: string) {
if (!target.hasOwnProperty(name)) {
return target._dht.hasOwnProperty(name);
}
return true;
},
});
}
}
export function hashDataKey(dataKey: string): Uint8Array {
return blake2b(encodeUtf8String(dataKey));
}
function encodeUtf8String(str: string): Uint8Array {
const byteArray = stringToUint8ArrayUtf8(str);
const encoded = new Uint8Array(8 + byteArray.length);
encoded.set(encodeNumber(byteArray.length));
encoded.set(byteArray, 8);
return encoded;
}
function stringToUint8ArrayUtf8(str: string): Uint8Array {
return Uint8Array.from(Buffer.from(str, "utf-8"));
}
function encodeNumber(num: number): Uint8Array {
const encoded = new Uint8Array(8);
for (let index = 0; index < encoded.length; index++) {
encoded[index] = num & 0xff;
num = num >> 8;
}
return encoded;
}