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https://github.com/arrow7000/qew
🚄 Library for queuing asynchronous functions - useful in interfacing with rate limited APIs or memory intensive operations
https://github.com/arrow7000/qew
async npm queue typescript
Last synced: 5 days ago
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🚄 Library for queuing asynchronous functions - useful in interfacing with rate limited APIs or memory intensive operations
- Host: GitHub
- URL: https://github.com/arrow7000/qew
- Owner: Arrow7000
- License: mit
- Created: 2017-05-09T23:19:01.000Z (over 7 years ago)
- Default Branch: master
- Last Pushed: 2023-02-04T15:04:40.000Z (almost 2 years ago)
- Last Synced: 2024-10-24T22:13:31.005Z (12 days ago)
- Topics: async, npm, queue, typescript
- Language: TypeScript
- Homepage:
- Size: 525 KB
- Stars: 63
- Watchers: 4
- Forks: 1
- Open Issues: 3
-
Metadata Files:
- Readme: README.md
- License: LICENSE
Awesome Lists containing this project
README
# Qew
A tiny library for queuing and throttling asynchronous functions.
Perfect for managing resource-intensive processes and controlling access to rate-limited APIs.
This project has 0 (zero) runtime dependencies 👌.
1. [Installation](#installation)
1. [API](#api)
1. [`Qew.constructor`](#new-qewmaxconcurrency1-delayordelayfunc0)
1. [`Qew.push`](#qewpushasyncfunction)
1. [Use cases](#use-cases)
1. [Methods & type signatures](#methods-and-type-signatures)
1. [Contributing](#contributing)
## Installation
Qew is available on npm. Install via
```
$ npm install qew
```
or
```
$ yarn add qew
```
## API
### `new Qew(maxConcurrency=1, delayOrDelayFunc=0)`
The constructor's type signature is
```typescript
constructor Qew(maxConcurrency: number = 1, delay: number | (() => number) = 0): Qew;
```
#### Examples
```typescript
const Qew = require("qew");
const qew = new Qew(); // maxConcurrency of 1, delay of 0ms
const qew = new Qew(3); // maxConcurrency of 3, delay of 0ms
const qew = new Qew(2, 250); // maxConcurrency of 2, delay of 250ms between end and start of functions
```
The delay parameter doesn't need to be a hardcoded number, you can also pass in a function that returns a number.
```typescript
const getRandomDelay = () => Math.random() * 1000;
const qew = new Qew(2, getRandomDelay);
// maxConcurrency of 2, delay will be a new random value between 0ms and 1000ms
```
### `Qew.push(asyncFunction)`
Type signature
```typescript
Qew.push(asyncFunc: () => Promise): Promise;
```
##### Examples
```typescript
// returns a promise, that runs when it is its turn in the queue.
// will resolve or reject depending on asyncFunc's resolution
const prom = qew.push(asyncFunc);
prom
.then(result => ...)
.catch(error => ...);
// `push`'s result can also be `await`ed in an async function like any promise
const doStuff = async () => {
const result = await qew.push(asyncFunc);
// do something with `result`
}
```
## Use cases
### Accessing rate-limited APIs
Basic example, queuing individual asynchronous functions.
```typescript
const qew = new Qew(1, 100); // for API that has a rate limit of 10 reqs/sec
qew.push(() => accessApi("a")).then(callback);
qew.push(() => accessApi("b")).then(callback);
qew.push(() => accessApi("c")).then(callback);
function callback(err, result) {
if (err) {
return console.error(err);
}
console.log(result);
}
```
## Methods and type signatures
```typescript
constructor Qew(maxConcurrent: number = 1, delay: number | (() => number) = 0): Qew;
Qew.push(asyncFunc: () => Promise): Promise;
```
## Contributing
Contributions are welcome! Feel free to file an issue or submit a pull request.