worker-thread.mjs

import thread from "node:worker_threads";
class ThreadPool {
    constructor(size,file) {
        this.file=file
        this.size=size
        this.wokerPool=new Map()
        this.idleWorker=new Set()
        this.taskQueue=[]
        this.activeWorker=new Map() 
        this.callback
        for (let index = 0; index < size; index++) {
            this.#createWorker()
            
        }
        for (const [key,value] of this.wokerPool) {
            this.idleWorker.add(key)
        }
    }
    #createWorker(){
        const worker=new thread.Worker(this.file)
        const id=worker.threadId
        worker.on('message',(msg)=>{
            const callback=this.activeWorker.get(msg.id)
            if (callback) {
                callback(msg.result)
            }
            this.idleWorker.add(msg.id)
            console.log('thread',msg.id,'is idle')
            this.#cleanUp(msg.id)
        })
        worker.on('error',(message)=>{
            console.log(message)
            this.wokerPool.delete(id)
            console.log('thread',msg.id,'was destroyed')
            const newWorker=this.#createWorker()
            this.idleWorker.add(newWorker.threadId)
            console.log('new thread created wit id:',msg.id,' and is idle')
            this.#cleanUp(id)
            

        })
        worker.on('exit',(code)=>{
            this.#cleanUp(id)
            if (code!==0) {
                this.wokerPool.delete(id)
                console.log('thread',msg.id,'was destroyed')
                const newWorker=this.#createWorker()
                this.idleWorker.add(newWorker.threadId)
                console.log('new thread created wit id:',msg.id,' and is idle')
            }
        })
        return this.wokerPool.set(id,worker)
    }
    #cleanUp(worker){
        this.activeWorker.delete(worker)
        this.#assignment(this.callback)
    }
    #assignment(callback){
        if (this.idleWorker.size===0||this.taskQueue.length===0) return
        const id=this.idleWorker.values().next().value
        const value=this.wokerPool.get(id)
        if (!value) {
            console.warn(`⚠️ Worker ${id} not found in pool.`)
            this.idleWorker.delete(id)
            this.#assignment(callback)
            return
        }
        const task=this.taskQueue.shift()
        this.activeWorker.set(id,callback)
        console.log(' thread :',id,' is now active')
        value.postMessage({id:id,task:task})
        //console.log(this.callback)
        this.idleWorker.delete(id)
    }
    run(data,callback){
        if (!Array.isArray(data)) {
            throw new TypeError('data is not an array')
        }
        this.callback=callback
        this.taskQueue=data
        for (let index = 0; index < this.wokerPool; index++) {
            this.#assignment(this.callback)
        }

    }
}
const data=[5,50,40,1]
const pool=new ThreadPool(4,'./test-worker.mjs')
pool.run(data,(result)=>{console.log(result)})