nodejs-threads/lib/defineWorker/index.js

A very simple functiobn based implementation of node.js worker threads

"use strict";
var __awaiter = (this && this.__awaiter) || function (thisArg, _arguments, P, generator) {
    function adopt(value) { return value instanceof P ? value : new P(function (resolve) { resolve(value); }); }
    return new (P || (P = Promise))(function (resolve, reject) {
        function fulfilled(value) { try { step(generator.next(value)); } catch (e) { reject(e); } }
        function rejected(value) { try { step(generator["throw"](value)); } catch (e) { reject(e); } }
        function step(result) { result.done ? resolve(result.value) : adopt(result.value).then(fulfilled, rejected); }
        step((generator = generator.apply(thisArg, _arguments || [])).next());
    });
};
Object.defineProperty(exports, "__esModule", { value: true });
const worker_threads_1 = require("worker_threads");
/**
 * Function to define what should be executed inside the worker thread.
 * The async function will be executed as soon as the worker thread is created.
 *
 * @param {Function} job Async function to be executed in the worker
 * @author Karan Raina <karanraina1996@gmail.com>
 * @created 27-DEC-2021
 *
 * @example
 *
 * // This code will execute in a separate thread
 * const { defineWorker } = require('nodejs-threads');
 * // OR
 * import { defineWorker } from 'nodejs-threads';
 * defineWorker(async (payload) => {
 *     console.log(payload); // Payload from the Primary thread is availbale here
 *
 *     // Do any CPU intensive task here.
 *     // The event loop in primary thread won't be blocked .
 *
 *     let result = 0;
 *     for (let i = 0; i < payload.range; i++) {
 *         result += i;
 *     }
 *     console.log('COMPLETED');
 *     return result;
 * });
 *
 * @returns Returns a promise which resolves to the result of the job
 */
function defineWorker(job) {
    return __awaiter(this, void 0, void 0, function* () {
        // return if it is primary thread
        if (worker_threads_1.isMainThread) {
            return null;
        }
        const result = yield job(worker_threads_1.workerData);
        if (worker_threads_1.parentPort) {
            worker_threads_1.parentPort.postMessage(result);
        }
    });
}
;
exports.default = defineWorker;