Rate limiting with Bacon.JS

Question

I'm trying to create a rate limiting when accessing an external API, using Bacon.JS

The rate limiting works fine, using bufferWithCount and bufferingThrottle but i would like to get the results when everything is flatmapped, not each batch at a time.

I've tries onEnd but it does not seem to be triggered.

Here's a fiddle: http://jsfiddle.net/9324jyLr/1/

var stream = new Bacon.Bus();

  stream
    .bufferWithCount(2)
    .bufferingThrottle(1000)
    .flatMap(batch => {
      batch = batch.map(x => x*2); //this should be an async API call returning Bacon.fromPromise(...)
      return Bacon.fromArray(batch);
    })
    // .bufferWithTime(1000)//one thang per interval
    .onValue(val => $('#log').append(val));

  for (var i=0; i<10; i++) {
    stream.push(i);
  }

score 1 · Accepted Answer · answered Mar 07 '16 at 12:32

You can use fold to combine the results and .end() to cause the Bus to end.

stream
    .bufferWithCount(2)
    .bufferingThrottle(1000)
    .flatMap(batch => {
      batch = batch.map(x => x*2); //this should be an async op
      return Bacon.fromArray(batch);
    })
    .fold([], (arr, val) => { return arr.concat(val) })
    // .bufferWithTime(1000)//one thang per interval
    .onValue(val => $('#log').append(val+"\n"));

  for (var i=0; i<10; i++) {
    stream.push(i);
  }
  stream.end()

http://jsfiddle.net/jdr9wuzy/

Rate limiting with Bacon.JS

1 Answers1