https://github.com/notanengineercom/simple-async-pool

Easy to use, dependency free and typesafe concurrent pool of async and promise returning functions
https://github.com/notanengineercom/simple-async-pool

async concurrency dependecy-free iterator no-dependencies nodejs pool promise typesafe typescript

Last synced: 4 months ago
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Easy to use, dependency free and typesafe concurrent pool of async and promise returning functions

• Host: GitHub
• URL: https://github.com/notanengineercom/simple-async-pool
• Owner: notanengineercom
• License: mit
• Created: 2021-02-06T22:13:52.000Z (almost 4 years ago)
• Default Branch: main
• Last Pushed: 2024-03-19T20:49:10.000Z (11 months ago)
• Last Synced: 2024-09-26T01:44:50.581Z (4 months ago)
• Topics: async, concurrency, dependecy-free, iterator, no-dependencies, nodejs, pool, promise, typesafe, typescript
• Language: TypeScript
• Homepage: https://www.npmjs.com/package/simple-async-pool
• Size: 76.2 KB
• Stars: 2
• Watchers: 1
• Forks: 0
• Open Issues: 0
• Metadata Files:
  • Readme: README.md
  • License: LICENSE

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README

        
# simple-async-pool

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Easy to use, dependency free and typesafe concurrent pool of async and promise returning functions.

## Installation

```sh

npm i simple-async-pool

```

## Usage

Using the async pool is really simple. The package exposes a `pool` function with the following simplified signature:

```ts

function pool(options: PoolOptions, consumerFunction, ...input)

function pool(consumerFunction, ...input)

```

The `PoolOptions` interface has the following members:

```ts

interface PoolOptions {

  output?: 'AsyncIterator' | 'Promise' // defines the return value of the pool function ('Promise' by default)

  concurrency?: number // defines the number of concurrent workers to spawn (1 by default)

}

```

By default, when no pool options are provided, the pool function returns a promise that resolves the processed input values with a concurrency of one:

```ts

import { pool } from 'simple-async-pool'

const consumerFunction = async (input: string) => input

const processedValues = await pool(consumerFunction, 'simple', 'async', 'pool') // if the input values are not strings, typescript complains due to the type missmatch

console.log(processedValues) // [ 'simple', 'async', 'pool' ]

```

The input values can either be an array (spread syntax), an iterator, an async iterator or a generator function (async/non async).

```ts

const processedValues = await pool(consumerFunction, 'simple', 'async', 'pool')

// ...

const input = ['simple', 'async', 'pool']

const processedValues = await pool(consumerFunction, input.values())

// ...

function* input() {

  yield 'simple'

  yield 'async'

  yield 'pool'

}

const processedValues = await pool(consumerFunction, input())

// ...

async function* input() {

  yield 'simple'

  yield 'async'

  yield 'pool'

}

const processedValues = await pool(consumerFunction, input())

console.log(processedValues) // [ 'simple', 'async', 'pool' ]

// ...

function* input() {

  yield 'simple'

  yield 'async'

  yield 'pool'

}

const processedValues = await pool(consumerFunction, input)

// ...

async function* input() {

  yield 'simple'

  yield 'async'

  yield 'pool'

}

const processedValues = await pool(consumerFunction, input)

console.log(processedValues) // [ 'simple', 'async', 'pool' ]

```

To modify the default behaviour, pool options can be provided as an argument:

```ts

const processedValues = await pool({ concurrency: 3 }, consumerFunction, 'simple', 'async', 'pool')

console.log(processedValues) // [ 'simple', 'async', 'pool' ]

```

Returning an async iterator instead of a promise can be achieved via the pool options too:

```ts

const iterator = pool({ concurrency: 3, output: 'AsyncIterator' }, consumerFunction, 'simple', 'async', 'pool')

const values = []

for await (const value of iterator) values.push(value)

```

When the `output` property in the options is set to `Promise` (default behaviour), the order of the output values is guaranteed.

When it's `AsyncIterator`, values are yielded in the order of resolution, so no order can be guaranteed.

## License

MIT © **Enrique Pöhlmann**