examples/typescript/http-server-pool/express-worker_threads/src/main.ts

   1 import { exit } from 'node:process'
   2 import express, { type Express, type Request, type Response } from 'express'
   3 import { requestHandlerPool } from './pool.js'
   4
   5 /**
   6  * The goal of this example is to show how to use the poolifier library to create a pool of workers that can handle HTTP requests.
   7  * The request handler pool can also be used as a middleware in the express stack: application or router level.
   8  *
   9  * The express server is still single-threaded, but the request handler pool is multi-threaded.
  10  */
  11
  12 const port = 8080
  13 const expressApp: Express = express()
  14
  15 const emptyFunction = (): void => {
  16   /* Intentional */
  17 }
  18
  19 // Parse only JSON requests body
  20 expressApp.use(express.json())
  21
  22 expressApp.all('/api/echo', (req: Request, res: Response) => {
  23   requestHandlerPool
  24     .execute({ body: req.body }, 'echo')
  25     .then(response => {
  26       return res.send(response.body).end()
  27     })
  28     .catch(emptyFunction)
  29 })
  30
  31 expressApp.get('/api/factorial/:number', (req: Request, res: Response) => {
  32   const { number } = req.params
  33   requestHandlerPool
  34     .execute({ body: { number: parseInt(number) } }, 'factorial')
  35     .then(response => {
  36       return res.send(response.body).end()
  37     })
  38     .catch(emptyFunction)
  39 })
  40
  41 try {
  42   expressApp.listen(port, () => {
  43     console.info(
  44       `⚡️[express server]: Express server is started at http://localhost:${port}/`
  45     )
  46   })
  47 } catch (err) {
  48   console.error(err)
  49   exit(1)
  50 }