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

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

mbostock

license: gpl-3.0

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.

---

KdotJPG

/**
 * K.jpg's OpenSimplex 2, smooth variant ("SuperSimplex")
 *
 * More language ports, as well as legacy 2014 OpenSimplex, can be found here:
 * https://github.com/KdotJPG/OpenSimplex2
 */

public class OpenSimplex2S {

    private static final long PRIME_X = 0x5205402B9270C86FL;

vbfox

module DapperFSharp =
    open System.Data.SqlClient
    open System.Dynamic
    open System.Collections.Generic
    open Dapper

    let dapperQuery<'Result> (query:string) (connection:SqlConnection) =
        connection.Query<'Result>(query)
    
    let dapperParametrizedQuery<'Result> (query:string) (param:obj) (connection:SqlConnection) : 'Result seq =

akras14

Git Cheat Sheet

Commands

Getting Started

git init

or

gerbsen

# content has to be in .config/fish/config.fish
# if it does not exist, create the file
setenv SSH_ENV $HOME/.ssh/environment

function start_agent                                                                                                                                                                    
    echo "Initializing new SSH agent ..."
    ssh-agent -c | sed 's/^echo/#echo/' > $SSH_ENV
    echo "succeeded"
    chmod 600 $SSH_ENV 
    . $SSH_ENV > /dev/null

vasanthk

System Design Cheatsheet

Picking the right architecture = Picking the right battles + Managing trade-offs

Basic Steps

1. 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?

TheAngryByrd

//http://www.navision-blog.de/blog/2015/12/21/adding-background-tasks-to-suave-io-websites/
let startApp path =
    let info = ProcessStartInfo(FileName = path)
    let proc = new System.Diagnostics.Process(StartInfo = info)
    
    start proc
    proc