fetch images and store in pouchdb

index.js

var path = require('path')
var Pouch = require('pouchdb')
var async = require('async')
var request = require('request')
var queue = async.queue(queueWorker, 5) // 5 requests at a time

var imageURLs = [
  "http://substack.net/images/ben.png",
  "http://substack.net/images/bed.png"
]

queue.drain = function() {
  console.log('downloaded all images!')
}

function queueWorker(opts, callback) {
  var db = opts.db
  var imageURL = opts.imageURL
  request(imageURL, function(err, resp, image) {
    if (err) return callback(err)
    var contentType = resp.headers['content-type']
    saveImageData(db, imageURL, image, contentType , callback)
  })
}

function saveImageData(db, imageURL, imageData, contentType, callback) {
  var extension = path.extname(imageURL)
  var filename = path.basename(imageURL, extension)
  db.put({_id: filename}, function(err, response) {
    db.putAttachment(response.id + '/image', response.rev, imageData, contentType, callback)
  })
}

Pouch("ldb://images", function(err, db) {
  if (err) return console.log(err)
  imageURLs.forEach(function(imageURL) {
    queue.push({db: db, imageURL: imageURL}, function() {
      console.log('stored', imageURL)
    })
  })
})