H hapr05

System Design Cheatsheet

Picking the right architecture = Picking the right battles + Managing trade-offs

Basic Steps

Clarify and agree on the scope of the system

User cases (description of sequences of events that, taken together, lead to a system doing something useful)
- Who is going to use it?
- How are they going to use it?

npm Users By Downloads (git.io/npm-top)

npm users sorted by the monthly downloads of their modules, for the range May 6, 2018 until Jun 6, 2018.

Metrics are calculated using top-npm-users.

#	User	Downloads

These links no longer work. Springer have pulled the free plug.

Graduate texts in mathematics

duplicates = multiple editions

A Classical Introduction to Modern Number Theory, Kenneth Ireland Michael Rosen

To make this work in CSS:

background: url('images.svg#chart');

or img:

<img src="images.svg#chart">

What forces layout / reflow

All of the below properties or methods, when requested/called in JavaScript, will trigger the browser to synchronously calculate the style and layout*. This is also called reflow or layout thrashing, and is common performance bottleneck.

Generally, all APIs that synchronously provide layout metrics will trigger forced reflow / layout. Read on for additional cases and details.

Element APIs

Getting box metrics

elem.offsetLeft, elem.offsetTop, elem.offsetWidth, elem.offsetHeight, elem.offsetParent

Gmail to Spreadsheet

superfish.pem contains:

the Superfish certificate as found by both Chris Palmer and Matt Burke;
the encrypted private key as found by Karl Koscher.

$ openssl x509 -in superfish.pem -text
Certificate:
    Data:
        Version: 3 (0x2)

	//Dr. Seuss once wrote, "IF." He meant, "If you give a fuck, maybe,
	//JUST MAYBE, you can change this shitty world in some small way for
	//the better." I might've been an writer of children's books someday,
	//but instead, I decided to make this. So in lieu of The Lorax,
	//let's call this The Dragon, and have my word be, "DON'T." As in,
	//"Don't do something stupid like this the way I did, you jackass."
	//But the truth is humans are very stubborn creatures. You probably
	//won't listen to my advice and, chances are, neither will I.

	//This is just an excerpt of the source code for DRAGON: A Game About

	/* bling.js */
	window.$ = document.querySelector.bind(document);
	window.$$ = document.querySelectorAll.bind(document);
	Node.prototype.on = window.on = function(name, fn) { this.addEventListener(name, fn); };
	NodeList.prototype.__proto__ = Array.prototype;
	NodeList.prototype.on = function(name, fn) { this.forEach((elem) => elem.on(name, fn)); };