import { clearTimeout, setTimeout } from "timers"; import { pack, unpack } from "msgpackr"; import { Buffer } from "buffer"; import { blake2b } from "libskynet"; export default class RpcQuery { _network; _query; _promise; _timeoutTimer; _timeout = false; _completed = false; _responses = {}; _promiseResolve; constructor(network, query) { this._network = network; this._query = query; this.init(); } get promise() { return this._promise; } handeTimeout() { this.resolve(false, true); } resolve(data, timeout = false) { clearTimeout(this._timeoutTimer); this._timeout = timeout; this._completed = true; // @ts-ignore this._promiseResolve(data); } async init() { this._promise = this._promise ?? new Promise((resolve) => { this._promiseResolve = resolve; }); this._timeoutTimer = this._timeoutTimer ?? setTimeout(this.handeTimeout.bind(this), this._network.queryTimeout * 1000); await this._network.ready; const promises = []; // tslint:disable-next-line:forin for (const relay of this._network.relays) { promises.push(this.queryRelay(relay)); } await Promise.allSettled(promises); this.checkResponses(); } async queryRelay(relay) { let socket; try { socket = this._network.dht.connect(Buffer.from(relay, "hex")); if (isPromise(socket)) { socket = await socket; } } catch (e) { return; } return new Promise((resolve, reject) => { socket.on("data", (res) => { socket.end(); const response = unpack(res); if (response && response.error) { return reject(response); } this._responses[relay] = response; resolve(null); }); socket.on("error", (error) => reject({ error })); socket.write(pack(this._query)); }); } checkResponses() { const responseStore = this._responses; const responseStoreData = Object.values(responseStore); const responseObjects = responseStoreData.reduce((output, item) => { const hash = Buffer.from(blake2b(Buffer.from(JSON.stringify(item?.data)))).toString("hex"); output[hash] = item?.data; return output; }, {}); const responses = responseStoreData.reduce((output, item) => { const hash = Buffer.from(blake2b(Buffer.from(JSON.stringify(item?.data)))).toString("hex"); output[hash] = output[hash] ?? 0; output[hash]++; return output; }, {}); for (const responseHash in responses) { if (responses[responseHash] / responseStoreData.length >= this._network.majorityThreshold) { // @ts-ignore const response = responseObjects[responseHash]; // @ts-ignore if (null === response) { this.retry(); return; } this.resolve(response); break; } } } retry() { this._responses = {}; if (this._completed) { return; } this.init(); } } function isPromise(obj) { return (!!obj && (typeof obj === "object" || typeof obj === "function") && typeof obj.then === "function"); }