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

   1 import type { Server } from 'http'
   2 import type { AddressInfo } from 'net'
   3 import {
   4   ClusterWorker,
   5   DynamicThreadPool,
   6   availableParallelism
   7 } from 'poolifier'
   8 import express, { type Express, type Request, type Response } from 'express'
   9 import {
  10   type ClusterWorkerData,
  11   type ClusterWorkerResponse,
  12   type DataPayload,
  13   type ThreadWorkerData,
  14   type ThreadWorkerResponse
  15 } from './types.js'
  16
  17 const emptyFunction = (): void => {
  18   /** Intentional */
  19 }
  20
  21 class ExpressWorker extends ClusterWorker<
  22 ClusterWorkerData,
  23 ClusterWorkerResponse
  24 > {
  25   private static server: Server
  26   private static requestHandlerPool: DynamicThreadPool<
  27   ThreadWorkerData<DataPayload>,
  28   ThreadWorkerResponse<DataPayload>
  29   >
  30
  31   private static readonly startExpress = (
  32     workerData?: ClusterWorkerData
  33   ): ClusterWorkerResponse => {
  34     const { port, workerFile, minWorkers, maxWorkers } =
  35       workerData as ClusterWorkerData
  36
  37     ExpressWorker.requestHandlerPool = new DynamicThreadPool<
  38     ThreadWorkerData<DataPayload>,
  39     ThreadWorkerResponse<DataPayload>
  40     >(
  41       minWorkers ?? 1,
  42       maxWorkers ?? availableParallelism(),
  43       workerFile,
  44       workerData
  45     )
  46
  47     const application: Express = express()
  48
  49     // Parse only JSON requests body
  50     application.use(express.json())
  51
  52     application.all('/api/echo', (req: Request, res: Response) => {
  53       ExpressWorker.requestHandlerPool
  54         .execute({ data: req.body }, 'echo')
  55         .then((response) => {
  56           return res.send(response.data).end()
  57         })
  58         .catch(emptyFunction)
  59     })
  60
  61     application.get('/api/factorial/:number', (req: Request, res: Response) => {
  62       const { number } = req.params
  63       ExpressWorker.requestHandlerPool
  64         .execute({ data: { number: parseInt(number) } }, 'factorial')
  65         .then((response) => {
  66           return res.send(response.data).end()
  67         })
  68         .catch(emptyFunction)
  69     })
  70
  71     ExpressWorker.server = application.listen(port, () => {
  72       console.info(
  73         // eslint-disable-next-line @typescript-eslint/restrict-template-expressions
  74         `⚡️[express server]: Express server is started in cluster worker at http://localhost:${workerData?.port}/`
  75       )
  76     })
  77     return {
  78       status: true,
  79       port:
  80         (ExpressWorker.server.address() as AddressInfo)?.port ??
  81         workerData?.port
  82     }
  83   }
  84
  85   public constructor () {
  86     super(ExpressWorker.startExpress, {
  87       killHandler: async () => {
  88         await ExpressWorker.requestHandlerPool.destroy()
  89         ExpressWorker.server.close()
  90       }
  91     })
  92   }
  93 }
  94
  95 export const expressWorker = new ExpressWorker()