Traffic-Limiter

Rate limit the number of tasks that can be run at any time, based on a task type.

Install

npm install traffic-limiter --save

Basic Use

When creating a Limiter, you need to specify type: limit configuration.

var Limiter = require("traffic-limiter");
 
var limiter = new Limiter({
  foo: 1
});
 
limiter.run("foo", function(done){
  // this one runs right away
  console.log("doing some 'foo' work");
  setTimeout(function(){
    done();
  }, 3000);
});
 
limiter.run("foo", function(done){
  // won't run until previous task is done
  console.log("doing more 'foo' work");
  done();
});

Complete A Task With A Ticket

Sometimes you don't have access to the done method from the run callback. In those cases, you can say a specific task was completed, by using the "ticket" that is returned from the run method:

var ticket = limiter.run("foo", function(){
  // do stuff
});
 
// later on
limiter.complete(ticket);

This will decrement the in-progress tasks for the specified type, allowing another task to run if needed.

Update Limits

You can update the limits any time you want by calling the updateLimits method.

limiter.updateLimits({
  foo: 2
});

Update The In-Progress Count

There may be times when you have to pre-set or reset the current in-progress count for a given task type. If you need to do this you can use the updateInProgress method.

limiter.updateInProgress({
  foo: 5
});

Changing this will immediately check to see if more tasks can run.

Unlimited Tasks

If you would like to have unlimited tasks running, set the limit for the type to any number below zero, such as -1.

limiter.updateLimits({
  foo: -1
});

Stop Running Tasks For A Type

If you want to prevent tasks from running at all, for a given type, set the limit to zero (0).

limiter.updateLimits({
  foo: 0
});

Legal Junk

Traffic-Limiter is ©2015 Muted Solutions, LLC. All Rights Reserved.

Distributed under MIT License