Poolifier-web-worker NPM

Deno, Bun and browser Web Worker Pool

Why Poolifier?

Poolifier is used to perform CPU and/or I/O intensive tasks on Deno, Bun or browser, it implements worker pools using web worker API module.\ With poolifier you can improve your performance and resolve problems related to the event loop.\ Moreover you can execute your tasks using an API designed to improve the developer experience.\ Please consult our general guidelines.

Easy to use ✔
Fixed and dynamic pool size ✔
Easy switch from a pool type to another ✔
Performance benchmarks ✔
Multiple JS runtime support at zero cost abstraction ✔
No runtime dependencies ✔
Support for ESM and TypeScript ✔
Support for web worker API module ✔
Tasks distribution strategies ✔
Lockless tasks queueing ✔
Queued tasks rescheduling:
- Task stealing on idle ✔
- Tasks stealing under back pressure ✔
- Tasks redistribution on worker error ✔
Support for sync and async task function ✔
Support for multiple task functions with per task function queuing priority and tasks distribution strategy ✔
Support for task functions CRUD operations at runtime ✔
General guidelines on pool choice ✔
Error handling out of the box ✔
Widely tested ✔
Active community ✔
Code quality
Code security

Overview

Poolifier contains web worker pool implementation, you don't have to deal with web worker API complexity.\ The first implementation is a fixed worker pool, with a defined number of workers that are started at creation time and will be reused.\ The second implementation is a dynamic worker pool, with a number of worker started at creation time (these workers will be always active and reused) and other workers created when the load will increase (with an upper limit, these workers will be reused when active), the newly created workers will be stopped after a configurable period of inactivity.\ You have to implement your worker by extending the ThreadWorker class.

Usage

Deno

deno add @poolifier/poolifier-web-worker

See Deno examples for more details:

Bun

npmjs

bun add poolifier-web-worker

JSR

bunx jsr add @poolifier/poolifier-web-worker

See Bun examples for more details:

Typescript

Browser

<script type="module">import { ThreadWorker } from 'https://cdn.jsdelivr.net/npm/poolifier-web-worker@0.4.31/browser/mod.js'</script>

<script type="module">
import {
  availableParallelism,
  DynamicThreadPool,
  FixedThreadPool,
  PoolEvents,
} from 'https://cdn.jsdelivr.net/npm/poolifier-web-worker@0.4.31/browser/mod.js'
</script>

Example code

You can implement a poolifier web worker in a simple way by extending the class ThreadWorker:

// adapt import to the targeted JS runtime
import { ThreadWorker } from '@poolifier/poolifier-web-worker'

function yourFunction(data) {
  // this will be executed in the worker thread,
  // the data will be received by using the execute method
  return { ok: 1 }
}

export default new ThreadWorker(yourFunction, {
  maxInactiveTime: 60000,
})

Instantiate your pool based on your needs :

// adapt import to the targeted JS runtime
import {
  availableParallelism,
  DynamicThreadPool,
  FixedThreadPool,
  PoolEvents,
} from '@poolifier/poolifier-web-worker'

// a fixed web worker pool
const pool = new FixedThreadPool(
  availableParallelism(),
  new URL('./yourWorker.js', import.meta.url),
  {
    errorEventHandler: (e) => {
      console.error(e)
    },
  },
)

pool.eventTarget?.addEventListener(
  PoolEvents.ready,
  () => console.info('Pool is ready'),
)
pool.eventTarget?.addEventListener(
  PoolEvents.busy,
  () => console.info('Pool is busy'),
)

// or a dynamic web worker pool
const pool = new DynamicThreadPool(
  Math.floor(availableParallelism() / 2),
  availableParallelism(),
  new URL('./yourWorker.js', import.meta.url),
  {
    errorEventHandler: (e) => {
      console.error(e)
    },
  },
)

pool.eventTarget?.addEventListener(
  PoolEvents.full,
  () => console.info('Pool is full'),
)
pool.eventTarget?.addEventListener(
  PoolEvents.ready,
  () => console.info('Pool is ready'),
)
pool.eventTarget?.addEventListener(
  PoolEvents.busy,
  () => console.info('Pool is busy'),
)

// the execute method signature is the same for both implementations,
// so you can easily switch from one to another
try {
  const res = await pool.execute()
  console.info(res)
} catch (err) {
  console.error(err)
}

Remember that workers can only send and receive structured-cloneable data.