src/charging-station/Worker.js

   1 const Configuration = require('../utils/Configuration');
   2 const {Worker} = require('worker_threads');
   3 const Pool = require('worker-threads-pool');
   4
   5 class Wrk {
   6   /**
   7    * Create a new `Wrk`.
   8    *
   9    * @param {String} workerScript
  10    * @param {Object} workerData
  11    */
  12   constructor(workerScript, workerData) {
  13     if (Configuration.useWorkerPool()) {
  14       this._pool = new Pool({max: Configuration.getWorkerPoolSize()});
  15     }
  16     this._workerData = workerData;
  17     this._workerScript = workerScript;
  18   }
  19
  20   /**
  21    *
  22    * @return {Promise}
  23    * @private
  24    */
  25   _startWorkerWithPool() {
  26     return new Promise((resolve, reject) => {
  27       this._pool.acquire(this._workerScript, {workerData: this._workerData}, (err, worker) => {
  28         if (err) {
  29           return reject(err);
  30         }
  31         worker.once('message', resolve);
  32         worker.once('error', reject);
  33       });
  34     });
  35   }
  36
  37   /**
  38    *
  39    * @return {Promise}
  40    * @private
  41    */
  42   _startWorker() {
  43     return new Promise((resolve, reject) => {
  44       const worker = new Worker(this._workerScript, {workerData: this._workerData});
  45       worker.on('message', resolve);
  46       worker.on('error', reject);
  47       worker.on('exit', (code) => {
  48         if (code !== 0) {
  49           reject(new Error(`Worker stopped with exit code ${code}`));
  50         }
  51       });
  52     });
  53   }
  54
  55   /**
  56    *
  57    * @return {Promise}
  58    * @public
  59    */
  60   start() {
  61     if (Configuration.useWorkerPool()) {
  62       return this._startWorkerWithPool();
  63     }
  64     return this._startWorker();
  65   }
  66 }
  67
  68 module.exports = Wrk;