examples/typescript/http-server-pool/express-hybrid/src/express-worker.ts

   1 import type { Server } from 'node:http'
   2 import type { AddressInfo } from 'node:net'
   3
   4 import express, { type Express, type Request, type Response } from 'express'
   5 import {
   6   availableParallelism,
   7   ClusterWorker,
   8   DynamicThreadPool,
   9 } from 'poolifier'
  10
  11 import type {
  12   ClusterWorkerData,
  13   ClusterWorkerResponse,
  14   DataPayload,
  15   ThreadWorkerData,
  16   ThreadWorkerResponse,
  17 } from './types.js'
  18
  19 const emptyFunction = (): void => {
  20   /* Intentional */
  21 }
  22
  23 class ExpressWorker extends ClusterWorker<
  24   ClusterWorkerData,
  25   ClusterWorkerResponse
  26 > {
  27   private static server: Server
  28   private static requestHandlerPool: DynamicThreadPool<
  29     ThreadWorkerData<DataPayload>,
  30     ThreadWorkerResponse<DataPayload>
  31   >
  32
  33   private static readonly startExpress = (
  34     workerData?: ClusterWorkerData
  35   ): ClusterWorkerResponse => {
  36     const { port, workerFile, minWorkers, maxWorkers, ...poolOptions } =
  37       // eslint-disable-next-line @typescript-eslint/no-non-null-assertion
  38       workerData!
  39
  40     ExpressWorker.requestHandlerPool = new DynamicThreadPool<
  41       ThreadWorkerData<DataPayload>,
  42       ThreadWorkerResponse<DataPayload>
  43     >(
  44       minWorkers ?? 1,
  45       maxWorkers ?? availableParallelism(),
  46       workerFile,
  47       poolOptions
  48     )
  49
  50     const application: Express = express()
  51
  52     // Parse only JSON requests body
  53     application.use(express.json())
  54
  55     application.all('/api/echo', (req: Request, res: Response) => {
  56       ExpressWorker.requestHandlerPool
  57         .execute({ data: req.body }, 'echo')
  58         .then(response => {
  59           return res.send(response.data).end()
  60         })
  61         .catch(emptyFunction)
  62     })
  63
  64     application.get('/api/factorial/:number', (req: Request, res: Response) => {
  65       const { number } = req.params
  66       ExpressWorker.requestHandlerPool
  67         .execute({ data: { number: Number.parseInt(number) } }, 'factorial')
  68         .then(response => {
  69           return res.send(response.data).end()
  70         })
  71         .catch(emptyFunction)
  72     })
  73
  74     let listenerPort: number | undefined
  75     ExpressWorker.server = application.listen(port, () => {
  76       listenerPort = (ExpressWorker.server.address() as AddressInfo).port
  77       console.info(
  78         `⚡️[express server]: Express server is started in cluster worker at http://localhost:${listenerPort.toString()}/`
  79       )
  80     })
  81     return {
  82       status: true,
  83       port: listenerPort ?? port,
  84     }
  85   }
  86
  87   public constructor () {
  88     super(ExpressWorker.startExpress, {
  89       killHandler: async () => {
  90         await ExpressWorker.requestHandlerPool.destroy()
  91         ExpressWorker.server.close()
  92       },
  93     })
  94   }
  95 }
  96
  97 export const expressWorker = new ExpressWorker()