jboner

Latency Comparison Numbers (~2012)
----------------------------------
L1 cache reference                           0.5 ns
Branch mispredict                            5   ns
L2 cache reference                           7   ns                      14x L1 cache
Mutex lock/unlock                           25   ns
Main memory reference                      100   ns                      20x L2 cache, 200x L1 cache
Compress 1K bytes with Zippy             3,000   ns        3 us
Send 1K bytes over 1 Gbps network       10,000   ns       10 us
Read 4K randomly from SSD*             150,000   ns      150 us          ~1GB/sec SSD

hellerbarde

Latency numbers every programmer should know

L1 cache reference ......................... 0.5 ns
Branch mispredict ............................ 5 ns
L2 cache reference ........................... 7 ns
Mutex lock/unlock ........................... 25 ns
Main memory reference ...................... 100 ns             
Compress 1K bytes with Zippy ............. 3,000 ns  =   3 µs
Send 2K bytes over 1 Gbps network ....... 20,000 ns  =  20 µs
SSD random read ........................ 150,000 ns  = 150 µs

Read 1 MB sequentially from memory ..... 250,000 ns = 250 µs

brysongilbert

// Vertical gradient using CSS where possible, and base64-encoded SVG for IE9 (enables use of this in combination with border-radius)
// Based on this by Phil Brown: http://blog.philipbrown.id.au/2012/09/base64-encoded-svg-gradient-backgrounds-in-less/
// Also based on a mixin from Twitter Bootstrap: https://github.com/twitter/bootstrap

.gradient-vertical(@startColor, @endColor) {

    // IE9 prep
    @dataPrefix: ~"url(data:image/svg+xml;base64,";
    @dataSuffix: ~")";
    @dataContent: ~'<svg xmlns="http://www.w3.org/2000/svg" width="100%" height="100%" viewBox="0 0 1 1" preserveAspectRatio="none"><linearGradient id="g743" gradientUnits="userSpaceOnUse" x1="0%" y1="0%" x2="0%" y2="100%"><stop stop-color="@{startColor}" offset="0"/><stop stop-color="@{endColor}" offset="1"/></linearGradient><rect x="0" y="0" width="1" height="1" fill="url(#g743)"/></svg>';

branneman

Better local require() paths for Node.js

Problem

When the directory structure of your Node.js application (not library!) has some depth, you end up with a lot of annoying relative paths in your require calls like:

const Article = require('../../../../app/models/article');

Those suck for maintenance and they're ugly.

Possible solutions

staltz

The introduction to Reactive Programming you've been missing

(by @andrestaltz)

---

This tutorial as a series of videos

If you prefer to watch video tutorials with live-coding, then check out this series I recorded with the same contents as in this article: Egghead.io - Introduction to Reactive Programming.

---

SerafimArts

• На iOS устройствах числовые значения подчёркиваются синим. Эта проблема возникает из-за того, что iOS устройства по умолчанию считают все числа похожие на телефонные номера - телефонными номерами. Решается добавлением <meta name="format-detection" content="telephone=no" /> Тоже самое касается адреса: <meta name="format-detection" content="address=no" />

• Пользователь может уменьшать и увеличивать приложение. Решается добавляением тега <meta name="viewport" content="user-scalable=no, initial-scale=1, maximum-scale=1, minimum-scale=1, width=device-width, height=device-height, target-densitydpi=device-dpi" />

• Ссылки нажимаются с задержкой (примерно 300ms). Решается подпиской на событие touchstart и принудительной инициализацией события click после него. Если проблема всё равно возникает - ничего не поделать, надо облегчать dom. Как вариант - можно использовать библиотеку, посоветанную @adubovsky ниже в комментариях: https://gist.github.com/SerafimArts/de9900f99

addyosmani

CSS Layout Debugger

A tweet-sized debugger for visualizing your CSS layouts. Outlines every DOM element on your page a random (valid) CSS hex color.

One-line version to paste in your DevTools

Use $$ if your browser aliases it:

~ 108 byte version

yoavniran

The Ultimate Unit Testing Cheat-sheet

---

• Sinon Chai
• Chai
• Sinon

paulirish

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

rauchg

Minimum Viable Async with Node 6

With the release of Node 6.0.0, the surface of code that needs transpilation to use ES6 features has been reduced very dramatically.

This is what my current workflow looks like to set up a minimalistic and fast microservice using micro and async + await.

The promise