Tao Wu metaphox

#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?

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.

Element

Box metrics

elem.offsetLeft, elem.offsetTop, elem.offsetWidth, elem.offsetHeight, elem.offsetParent
elem.clientLeft, elem.clientTop, elem.clientWidth, elem.clientHeight
elem.getClientRects(), elem.getBoundingClientRect()

	" MINIMAL VERSION WITHOUT ANY DEPENDENCY


	" For compatibility's sake, all defaults that are different between Vim and
	" Neovim are excplicity specified again.

	" look and feel
	set t_Co=256
	set background=dark
	" remove windows toolbar

	_DEFAULTS = [
	a : '123',
	b : '456',
	c : []
	]

	def foo = [ a : '789', c : ['000', '111', 222] ]

	def getTemplate() {
	return """

	from PyQt5.QtGui import QPixmap, QImage
	from PyQt5.QtWidgets import QApplication, QLabel

	import sys

	from cv2 import VideoCapture

	if __name__ == '__main__':
	qa = QApplication(sys.argv)
	ql = QLabel()

	#!/usr/bin/env python


	#############################################################################
	##
	## Copyright (C) 2013 Riverbank Computing Limited.
	## Copyright (C) 2013 Digia Plc and/or its subsidiary(-ies).
	## All rights reserved.
	##
	## This file is part of the examples of PyQt.

	#!/bin/bash

	SCRIPTNAME=`basename "$0"`

	print_help() {
	cat << EOF
	Usage: $SCRIPTNAME filename
	Uses 'inotifywait' to sleep until 'filename' has been modified.

	Inspired by http://superuser.com/questions/181517/how-to-execute-a-command-whenever-a-file-changes/181543#181543

	import sys, json, datetime

	if len(sys.argv) < 2:
	filename = 'myzhihuanswers.json'
	else:
	filename = sys.argv[1]
	with open(filename) as jsonfile:
	lines = jsonfile.readlines()
	i = 0
	for pageline in lines:

	/* bling.js */

	window.$ = document.querySelectorAll.bind(document)

	Node.prototype.on = window.on = function (name, fn) {
	this.addEventListener(name, fn)
	}

	NodeList.prototype.__proto__ = Array.prototype