axios-rate-limiter

axios-rate-limiter.js

import axios from 'axios'

const CONCURRENT_UPLOADS = 6

// Time between verifications to know if there's
// a space on the queue to make a new request
const INTERVAL_MS = 10

let PENDING_UPLOADS = 0

const upload = axios.create({})

// Intercepts the request and stops it till the 
// queue has space enough to make a new one
upload.interceptors.request.use(function (config) {
  return new Promise(resolve => {
    let interval = setInterval(() => {
      if (PENDING_UPLOADS < CONCURRENT_UPLOADS) {
        PENDING_UPLOADS++
        clearInterval(interval)
        resolve(config)
      } 
    }, INTERVAL_MS)
  })
})

// Intercepts the response to free up space on the
// queue.
upload.interceptors.response.use(function (response) {
  PENDING_UPLOADS = Math.max(0, PENDING_UPLOADS - 1)
  return Promise.resolve(response)
}, function (error) {
  PENDING_UPLOADS = Math.max(0, PENDING_UPLOADS - 1)
  return Promise.reject(error)
})

export default upload