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

browny

/* --- Usage --- */
g++ server.c -o server
g++ client.c -o client
./server
./client 127.0.0.1

/* --- server.c --- */
#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>

tsiege

ANNOUNCEMENT

I have moved this over to the Tech Interview Cheat Sheet Repo and has been expanded and even has code challenges you can run and practice against!






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neauoire

-- 3D CUBE
-- BY ALICEFFEKT

angle = 0

function _update()
	angle += 2
	if angle > 360 then
	 angle = 0
	end

glowcoil

// motion_add(dir, spd):

vx += spd * cos(dir);
vy -= spd * sin(dir);

// setting speed to spd:

var current_speed;
current_speed = sqrt(vx*vx + vy*vy);
vx *= spd / current_speed;

angusjf

{
    "ad": {
        "flag": "🇦🇩",
        "name": "Andorra",
        "dialCode": "+376"
    },
    "ae": {
        "flag": "🇦🇪",
        "name": "United Arab Emirates",
        "dialCode": "+971"

OrionReed

// 3D Dom viewer, copy-paste this into your console to visualise the DOM as a stack of solid blocks.
// You can also minify and save it as a bookmarklet (https://www.freecodecamp.org/news/what-are-bookmarklets/)
(() => {
  const SHOW_SIDES = false; // color sides of DOM nodes?
  const COLOR_SURFACE = true; // color tops of DOM nodes?
  const COLOR_RANDOM = false; // randomise color?
  const COLOR_HUE = 190; // hue in HSL (https://hslpicker.com)
  const MAX_ROTATION = 180; // set to 360 to rotate all the way round
  const THICKNESS = 20; // thickness of layers
  const DISTANCE = 10000; // ¯\\_(ツ)_/¯