https://github.com/ForbesLindesay/throat

Throttle a collection of promise returning functions
https://github.com/ForbesLindesay/throat

concurrency flow promise typescript

Last synced: 15 days ago
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Throttle a collection of promise returning functions

• Host: GitHub
• URL: https://github.com/ForbesLindesay/throat
• Owner: ForbesLindesay
• License: mit
• Created: 2012-12-21T10:58:14.000Z (almost 12 years ago)
• Default Branch: master
• Last Pushed: 2023-01-03T13:31:48.000Z (almost 2 years ago)
• Last Synced: 2024-10-19T13:57:14.743Z (23 days ago)
• Topics: concurrency, flow, promise, typescript
• Language: JavaScript
• Size: 85 KB
• Stars: 484
• Watchers: 4
• Forks: 40
• Open Issues: 13
• Metadata Files:
  • Readme: README.md
  • Funding: .github/FUNDING.yml
  • License: LICENSE
  • Security: SECURITY.md

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• stars - ForbesLindesay/throat

README

        
# throat

Throttle the parallelism of an asynchronous, promise returning, function / functions. This has special utility when you set the concurrency to `1`. That way you get a mutually exclusive lock.

[Professionally supported throat is now available](https://tidelift.com/subscription/pkg/npm-throat?utm_source=npm-throat&utm_medium=referral&utm_campaign=readme)

[![Build Status](https://img.shields.io/github/actions/workflow/status/ForbesLindesay/throat/test.yml?branch=master&style=for-the-badge)](https://github.com/ForbesLindesay/throat/actions/workflows/test.yml?query=branch%3Amaster)

[![Coveralls github branch](https://img.shields.io/coveralls/github/ForbesLindesay/throat/master?color=brightgreen&style=for-the-badge)](https://coveralls.io/github/ForbesLindesay/throat)

[![Rolling Versions](https://img.shields.io/badge/Rolling%20Versions-Enabled-brightgreen?style=for-the-badge)](https://rollingversions.com/ForbesLindesay/throat)

[![NPM version](https://img.shields.io/npm/v/throat?style=for-the-badge)](https://www.npmjs.com/package/throat)

## Installation

    npm install throat

## API

### throat(concurrency)

This returns a function that acts a bit like a lock (exactly as a lock if concurrency is 1).

Example, only 2 of the following functions will execute at any one time:

```js

const throat = require('throat')(2);

const resA = throat(async () => {

  /* async stuff... */

});

const resB = throat(async () => {

  /* async stuff... */

});

const resC = throat(async () => {

  /* async stuff... */

});

const resD = throat(async () => {

  /* async stuff... */

});

const resE = throat(async () => {

  /* async stuff... */

});

```

### throat(concurrency, worker)

This returns a function that is an exact copy of `worker` except that it will only execute up to `concurrency` times in parallel before further requests are queued:

```js

const throat = require('throat');

const input = ['fileA.txt', 'fileB.txt', 'fileC.txt', 'fileD.txt'];

const data = Promise.all(

  input.map(throat(2, (fileName) => readFile(fileName)))

);

```

Only 2 files will be read at a time, sometimes limiting parallelism in this way can improve scalability.

## Security contact information

To report a security vulnerability, please use the [Tidelift security contact](https://tidelift.com/security). Tidelift will coordinate the fix and disclosure.

## License

MIT