Robin van der Vleuten robinvdvleuten

Scaling your API with rate limiters

The following are examples of the four types rate limiters discussed in the accompanying blog post. In the examples below I've used pseudocode-like Ruby, so if you're unfamiliar with Ruby you should be able to easily translate this approach to other languages. Complete examples in Ruby are also provided later in this gist.

In most cases you'll want all these examples to be classes, but I've used simple functions here to keep the code samples brief.

Request rate limiter

This uses a basic token bucket algorithm and relies on the fact that Redis scripts execute atomically. No other operations can run between fetching the count and writing the new count.

Dynamically Add Critical CSS to Your Rails App

Optimizing the delivery of CSS is one way to improve user experience, load speed and SEO of your web app. This involves determining the "critical path CSS" and embeding it into the html of your page. The rest of the CSS for the site is loaded asynchronously so it does not block the rendering of your "above the fold" content. This Gist will show you how to dynamically generate critical path CSS for your Rails app.

In this example we will use the mudbugmedia/critical-path-css gem.

Prerequisites

You will need to set up caching and Active Job in your Rails app. I recommend using a thread-safe background job manager like resque.

pure() can be used as a higher order function or a decorator.

When passed a pure functional component, it wraps the function in a classful Component with a shouldComponentUpdate() that ignores renders for unchanged props.

When passed a classful Component, it injects a shouldComponentUpdate() method into the Component's prototype that ignores renders for unchanged props & state.

Functional Example

import pure from 'pure-component';

Docker - How to cleanup (unused) resources

Once in a while, you may need to cleanup resources (containers, volumes, images, networks) ...

delete volumes

// see: https://github.com/chadoe/docker-cleanup-volumes

$ docker volume rm $(docker volume ls -qf dangling=true)

$ docker volume ls -qf dangling=true | xargs -r docker volume rm

RxJS 5 Operators By Example

⚠️ UPDATE: I have moved the contents of this gist plus more to http://www.learnrxjs.io and https://github.com/btroncone/learn-rxjs. For expanded examples, explanations, and resources, please check out this new location!

A complete list of RxJS 5 operators with easy to understand explanations and runnable examples.

This is an auth example (WIP)

react + redux + RR

It uses https://gist.github.com/iNikNik/3c1b870f63dc0de67c38 for stores and actions.

1) create redux

const redux = createRedux(state);

2) get requireAccess func => bindCheckAuth to redux

	// Creates a new promise that automatically resolves after some timeout:
	Promise.delay = function (time) {
	return new Promise((resolve, reject) => {
	setTimeout(resolve, time)
	})
	}

	// Throttle this promise to resolve no faster than the specified time:
	Promise.prototype.takeAtLeast = function (time) {
	return new Promise((resolve, reject) => {

	import { h, Component } from 'preact';


	/** Creates a new store, which is a tiny evented state container.
	* @example
	* let store = createStore();
	* store.subscribe( state => console.log(state) );
	* store.setState({ a: 'b' }); // logs { a: 'b' }
	* store.setState({ c: 'd' }); // logs { c: 'd' }
	*/

	import { createCipheriv, createDecipheriv, randomBytes } from "crypto";

	const ENCRYPTION_KEY: string = process.env.ENCRYPTION_KEY \|\| ""; // Must be 256 bits (32 characters)
	const IV_LENGTH: number = 16; // For AES, this is always 16

	/**
	* Will generate valid encryption keys for use
	* Not used in the code below, but generate one and store it in ENV for your own purposes
	*/
	export function keyGen() {

	{
	"env": {
	"browser": true,
	"node": true,
	"es6": true
	},

	"plugins": ["react"],

	"ecmaFeatures": {