Greg Ingelmo GregIngelmo

Slack has listened to feedback and given us a way to toggle off the sidebar avatars.

~~(This only seems to be available in the Beta channel at the moment)~~

From your desktop, click your profile picture in the top right.
Select Preferences from the menu.
Click Sidebar in the left-side column.
Check or uncheck the boxes next to Show profile photos next to DMs.

Latency numbers every programmer should know

L1 cache reference ......................... 0.5 ns
Branch mispredict ............................ 5 ns                     on recent CPU
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 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 4X memory

Benchmarking Nginx with Go

There are a lot of ways to serve a Go HTTP application. The best choices depend on each use case. Currently nginx looks to be the standard web server for every new project even though there are other great web servers as well. However, how much is the overhead of serving a Go application behind an nginx server? Do we need some nginx features (vhosts, load balancing, cache, etc) or can you serve directly from Go? If you need nginx, what is the fastest connection mechanism? This are the kind of questions I'm intended to answer here. The purpose of this benchmark is not to tell that Go is faster or slower than nginx. That would be stupid.

So, these are the different settings we are going to compare:

Go HTTP standalone (as the control group)
Nginx proxy to Go HTTP
Nginx fastcgi to Go TCP FastCGI
Nginx fastcgi to Go Unix Socket FastCGI

	import Cocoa
	import MetalKit

	@NSApplicationMain
	class AppDelegate: NSObject, NSApplicationDelegate, MTKViewDelegate {
	weak var window: NSWindow!
	weak var metalView: MTKView!
	let device = MTLCreateSystemDefaultDevice()!
	var commandQueue: MTLCommandQueue!
	var pipelineState: MTLRenderPipelineState!

	func emojiToImage(text: String, size: CGFloat) -> UIImage {

	let outputImageSize = CGSize.init(width: size, height: size)
	let baseSize = text.boundingRect(with: CGSize(width: 2048, height: 2048),
	options: .usesLineFragmentOrigin,
	attributes: [.font: UIFont.systemFont(ofSize: size / 2)], context: nil).size
	let fontSize = outputImageSize.width / max(baseSize.width, baseSize.height) * (outputImageSize.width / 2)
	let font = UIFont.systemFont(ofSize: fontSize)
	let textSize = text.boundingRect(with: CGSize(width: outputImageSize.width, height: outputImageSize.height),
	options: .usesLineFragmentOrigin,

	// file: index.js

	var _ = require("lodash");
	var express = require("express");
	var bodyParser = require("body-parser");
	var jwt = require('jsonwebtoken');

	var passport = require("passport");
	var passportJWT = require("passport-jwt");

	/**
	* Fancy ID generator that creates 20-character string identifiers with the following properties:
	*
	* 1. They're based on timestamp so that they sort after any existing ids.
	* 2. They contain 72-bits of random data after the timestamp so that IDs won't collide with other clients' IDs.
	* 3. They sort lexicographically (so the timestamp is converted to characters that will sort properly).
	* 4. They're monotonically increasing. Even if you generate more than one in the same timestamp, the
	* latter ones will sort after the former ones. We do this by using the previous random bits
	* but "incrementing" them by 1 (only in the case of a timestamp collision).
	*/

	var BitField = (function () {
	"use strict";

	function BitField (bits) {
	if (Array.isArray(bits)) {
	return BitField.fromJSON(bits);
	}
	else if (typeof bits === "string") {
	return BitField.fromBase64(bits);
	}

	import Foundation

	extension String
	{
	var length: Int {
	get {
	return countElements(self)
	}
	}

	//
	// ViewController.m
	// AVPlayerCaching
	//
	// Created by Anurag Mishra on 5/19/14.
	// Sample code to demonstrate how to cache a remote audio file while streaming it with AVPlayer
	//

	#import "ViewController.h"
	#import <AVFoundation/AVFoundation.h>