jaabiri salim jaabiri

How to make faster scroll effects?

Avoid too many reflows (the browser to recalculate everything)
Use advanced CSS3 for graphic card rendering
Precalculate sizes and positions

Beware of reflows

The reflow appens as many times as there are frames per seconds. It recalculate all positions that change in order to diplay them. Basically, when you scroll you execute a function where you move things between two reflows. But there are functions that triggers reflows such as jQuery offset, scroll... So there are two things to take care about when you dynamically change objects in javascript to avoid too many reflows:

Disclaimer

I'm still very new to Kafka, eventsourcing, stream processing, etc. I'm in the middle of building my first production system with this stuff and am writing this at the request of a few folks on Twitter. So if you do have experience, please do me and anyone else reading this a favor by pointing out things I get wrong :)

Inspirations

The Log — http://engineering.linkedin.com/distributed-systems/log-what-every-software-engineer-should-know-about-real-time-datas-unifying
Turning the database inside out — http://www.confluent.io/blog/2015/03/04/turning-the-database-inside-out-with-apache-samza/
Why local state is a fundamental primitive in stream processing — http://radar.oreilly.com/2014/07/why-local-state-is-a-fundamental-primitive-in-stream-processing.html
Samza
Various functional systems been exposed to over past year or so, React, Flux, RX, etc.

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

@kangax's ES6 quiz, explained

@kangax created a new interesting quiz, this time devoted to ES6 (aka ES2015). I found this quiz very interesting and quite hard (made myself 3 mistakes on first pass).

Here we go with the explanations:

Question 1:

(function(x, f = () =&gt; x) {

A curated list of AWS resources to prepare for the AWS Certifications

A curated list of awesome AWS resources you need to prepare for the all 5 AWS Certifications. This gist will include: open source repos, blogs & blogposts, ebooks, PDF, whitepapers, video courses, free lecture, slides, sample test and many other resources.

Thanks everyone for participating in the quiz!
Many of you have posted correct answers.

What we know:

A top-level App component returns <Button /> from its render() method.

Question:

>What is the relationship between `` and this in that `Button`’s `render()`?

Problem: How can we preprocess JavaScript (at build-time or on the server-side) so engines like V8 don't have to spend as much time in Parse? This is a topic that involves generating either bytecode or a bytecode-like-abstraction that an engine would need to accept. For folks that don't know, modern web apps typically spend a lot longer in Parsing & Compiling JS than you may think.

Yoav: This can particularly be an issue on mobile. Same files getting parsed all the time for users. Theoretically if we moved the parsing work to the server-side, we would have to worry about it less.
One angle to this problem is we all ship too much JavaScript. That's one perspective. We could also look at preprocessing.
We've been talking about this topic over the last few weeks a bit with V8. There were three main options proposed.
1. Similar to what optimize-js does. Identify IIFEs and mark them as such so the browser and VMs heuristics will catch them and do a better job than today. optimize-js only tackles IIFE bu

	var data = {
	"name": "root",
	"contents": [
	{
	"name": "A",
	"contents": [
	{
	"name": "fileA1",
	"contents": []
	}

	// See https://blog.isquaredsoftware.com/presentations/react-redux-ts-intro-2020-12/#/36 for slides
	// My basic render function structure:
	function RenderLogicExample({
	someBoolean, // 1) Destructure values from `props` object
	someList,
	}) {
	// 2) Declare state values
	const [a, setA] = useState(0);
	const [b, setB] = useState(0);

	DELETE syntest
	PUT syntest
	{
	"mappings": {
	"article": {
	"properties": {
	"text": {
	"type": "string",
	"analyzer": "syn_text"
	}