Aleksey Litvinov mightyaleksey

Приёмы оптимизации кода по скорости

Организационные

Культура разработки performance-first: https://tonsky.me/blog/performance-first/
Бюджет скорости: https://wp-rocket.me/blog/performance-budgets/
Performance mantra: http://www.brendangregg.com/blog/2018-06-30/benchmarking-checklist.html

Не зависящие от языка и его реализации

Rosetta Code - реализации задач на разных языках: http://rosettacode.org/wiki/Collections
Статьи по основным структурам данных:

ZSH CheatSheet

This is a cheat sheet for how to perform various actions to ZSH, which can be tricky to find on the web as the syntax is not intuitive and it is generally not very well-documented.

Strings

Description	Syntax
Get the length of a string	`${#VARNAME}`
Get a single character	`${VARNAME[index]}`

Примеры можно попробовать в редакторе http://www.kickjs.org/tool/shader_editor/shader_editor.html

Значения uniform задаются на вкладке Uniforms (не забываем жать Update).

Вершинный шейдер

Общий для всех шейдеров:

precision highp float;

Uninstall brew package and dependencies

Remove package's dependencies (does not remove package):

brew deps [FORMULA] | xargs brew remove --ignore-dependencies

Remove package:

To clear 307 HSTS redirects in Google Chrome (if you experimenting with SSL -- you probably wouldn't want to do this for a site that you do not opperate, since it is there to protect you), go to the following URL and delete the site.

chrome://net-internals/#hsts

How to style React components

If you use sass and css-modules and want to restyle some base component without changing its code. (base component already use css-modules and exposes styles property)

I know two way how to do it.

Using composes css-modules operator. Just extend classes you need, then in javascript code combine both styles as {...baseStyle, ...myStyleSimple}

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

	<html>
	<body>
	<p>
	The actual canvas, where drawing happens. Mouse over to move the green open circle object.
	</p>
	<canvas id="canvas" width=200 height=200></canvas>
	<p id="result">

	</p>
	<p id="timing">

	import AVFoundation
	import PlaygroundSupport

	PlaygroundPage.current.needsIndefiniteExecution = true

	class AudioPlayer {
	var topAudioFiles: [AVAudioFile] = []
	var engine:AVAudioEngine
	var backgroundAudioNode: AVAudioPlayerNode
	var backgroundAudioFile: AVAudioFile

	"""Perlin noise implementation."""
	# Licensed under ISC
	from itertools import product
	import math
	import random


	def smoothstep(t):
	"""Smooth curve with a zero derivative at 0 and 1, making it useful for
	interpolating.