@supercharge/promise-pool

Promise Pool

Map-like, concurrent promise processing for Node.js.

Installation · Usage · API

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Installation

npm i @supercharge/promise-pool

Usage

Using the promise pool is pretty straightforward. The pacakge exposes a class and you can create a promise pool instance using the fluent interface. Here’s a working example:

const PromisePool = require('@supercharge/promise-pool')

const users = [
  { name: 'Marcus' },
  { name: 'Norman' },
  { name: 'Christian' }
]

const { results, errors } = await new PromisePool()
  .for(users)
  .withConcurrency(2)
  .process(async user => {
    const user = await User.createIfNotExisting(user)

    return user
  })

API

new PromisePool({ concurrency?, items? }) constructor

Creates a new promise pool. The constructor takes an optional options object allowing you to passing in the concurrency and items.

const pool = new PromisePool({ concurrency: 2, items: [1, 2, 3] })

.withConcurrency(amount)

Set the maximum number of functions to process in parallel. Default concurrency: 10. Returns the promise pool instance.

const pool = new PromisePool().withConcurrency(5)

.for(items)

Set the items to be processed in the promise pool. Returns the promise pool instance.

const users = [
  { name: 'Marcus' },
  { name: 'Norman' },
  { name: 'Christian' }
]

const pool = new PromisePool().withConcurrency(5).for(users)

.process(callback)

Starts processing the promise pool by iterating over the items and passing each item to the async mapper function. Returns an object containing the results and errors.

const users = [
  { name: 'Marcus' },
  { name: 'Norman' },
  { name: 'Christian' }
]

const pool = new PromisePool().withConcurrency(5).for(users)

const { results, errors } = await pool.process(async (user) => {
  await User.createIfNotExisting(user)
})

Contributing

1. Create a fork
2. Create your feature branch: git checkout -b my-feature
3. Commit your changes: git commit -am 'Add some feature'
4. Push to the branch: git push origin my-new-feature
5. Submit a pull request 🚀

License

MIT © Supercharge

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