DanisHack

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

DanisHack

# Compiled source #
###################
*.com
*.class
*.dll
*.exe
*.o
*.so

# Packages #

DanisHack

/*!
 * Grunt
 * $ npm install grunt-contrib-uglify grunt-autoprefixer grunt-contrib-cssmin grunt-contrib-imagemin grunt-contrib-sass grunt-contrib-watch grunt-contrib-concat grunt-contrib-clean grunt-contrib-jshint grunt-notify --save-dev
 */

module.exports = function(grunt) {

  grunt.initConfig({

    // Sass

DanisHack

• http://muratbuffalo.blogspot.com/2015/12/my-distributed-systems-seminars-reading.html
• http://christophermeiklejohn.com/distributed/systems/2013/07/12/readings-in-distributed-systems.html
• http://michaelrbernste.in/2013/11/06/distributed-systems-archaeology-works-cited.html
• http://dancres.org/reading_list.html
• http://rxin.github.io/db-readings/
• http://research.microsoft.com/en-us/um/people/lamport/pubs/pubs.html
• http://www.eecs.berkeley.edu/GradAffairs/CS/Prelims/db.html
• http://pdos.csail.mit.edu/dsrg/papers/
• http://scalingsystems.com/2011/09/07/reading-list-for-distributed-systems/
• http://courses.engr.illinois.edu/cs525/sp2011/sched.htm

DanisHack

Setup remote git repo on EC2

Create a bare repository

$ mkdir <repo-name>.git
$ cd <repo-name>.git
$ git init --bare

DanisHack

// Create a dummy analytics object until real loaded
window.analytics || (window.analytics = []);
window.analytics.methods = ['identify', 'track', 'trackLink', 'trackForm', 'trackClick', 'trackSubmit', 'page', 'pageview', 'ab', 'alias', 'ready', 'group', 'on', 'once', 'off'];
window.analytics.factory = function(method) {
  return function() {
    var args = Array.prototype.slice.call(arguments);
    args.unshift(method);
    window.analytics.push(args);
    return window.analytics;
  };

DanisHack

// Two ways to serve transparent GIF

var buf = new Buffer([
    0x47, 0x49, 0x46, 0x38, 0x39, 0x61, 0x01, 0x00, 0x01, 0x00, 
    0x80, 0x00, 0x00, 0xff, 0xff, 0xff, 0x00, 0x00, 0x00, 0x2c, 
    0x00, 0x00, 0x00, 0x00, 0x01, 0x00, 0x01, 0x00, 0x00, 0x02, 
    0x02, 0x44, 0x01, 0x00, 0x3b]);

res.send(buf, { 'Content-Type': 'image/gif' }, 200);

DanisHack

#!/bin/bash
set -x 

declare -r apacheMavenDownloadUrl="http://apache.cbox.biz/maven/maven-3/3.3.9/binaries/apache-maven-3.3.9-bin.tar.gz"
declare -r directoryName="mvn/"

if [[ $apacheMavenDownloadUrl =~ ([^/]+)\-bin\.tar\.gz$ ]]
then
    declare -r resultFileName=$BASH_REMATCH
    declare -r resultDirectoryName=${BASH_REMATCH[1]}

DanisHack

/* global chrome, MediaRecorder, FileReader */

chrome.runtime.onConnect.addListener(port => {
  let recorder = null
  port.onMessage.addListener(msg => {
    console.log(msg);
    switch (msg.type) {
      case 'REC_STOP':
        console.log('Stopping recording')
        if (!port.recorderPlaying || !recorder) {

DanisHack

ffmpeg -f lavfi -i anullsrc=r=11025:cl=mono -t <number of seconds> -acodec aac out.m4a