Source: workers/parent-browser.js

  1. /*!
  2.  * parent.js - worker processes for bcoin
  3.  * Copyright (c) 2014-2017, Christopher Jeffrey (MIT License).
  4.  * https://github.com/bcoin-org/bcoin
  5.  */
  7. 'use strict';
  9. const assert = require('bsert');
  10. const EventEmitter = require('events');
  12. /**
  13.  * Parent
  14.  * Represents the parent process.
  15.  * @alias module:workers.Parent
  16.  * @extends EventEmitter
  17.  * @ignore
  18.  */
  20. class Parent extends EventEmitter {
  21.   /**
  22.    * Create the parent process.
  23.    * @constructor
  24.    */
  26.   constructor() {
  27.     super();
  29.     this.init();
  30.   }
  32.   /**
  33.    * Initialize master (web workers).
  34.    * @private
  35.    */
  37.   init() {
  38.     global.onerror = (event) => {
  39.       this.emit('error', new Error('Worker error.'));
  40.     };
  42.     global.onmessage = (event) => {
  43.       let data;
  44.       if (typeof event.data === 'string') {
  45.         data = Buffer.from(event.data, 'hex');
  46.         assert(data.length === event.data.length / 2);
  47.       } else {
  48.         assert(event.data && typeof event.data === 'object');
  49.         assert(event.data.data && typeof event.data.data.length === 'number');
  50.         data = event.data.data;
  51.         data.__proto__ = Buffer.prototype;
  52.       }
  53.       this.emit('data', data);
  54.     };
  55.   }
  57.   /**
  58.    * Send data to parent process.
  59.    * @param {Buffer} data
  60.    * @returns {Boolean}
  61.    */
  63.   write(data) {
  64.     if (global.postMessage.length === 2) {
  65.       data.__proto__ = Uint8Array.prototype;
  66.       global.postMessage({ data }, [data]);
  67.     } else {
  68.       global.postMessage(data.toString('hex'));
  69.     }
  70.     return true;
  71.   }
  73.   /**
  74.    * Destroy the parent process.
  75.    */
  77.   destroy() {
  78.     global.close();
  79.   }
  80. }
  82. /*
  83.  * Expose
  84.  */
  86. module.exports = Parent;