isaacs

echo 'export PATH=$HOME/local/bin:$PATH' >> ~/.bashrc
. ~/.bashrc
mkdir ~/local
mkdir ~/node-latest-install
cd ~/node-latest-install
curl http://nodejs.org/dist/node-latest.tar.gz | tar xz --strip-components=1
./configure --prefix=~/local
make install # ok, fine, this step probably takes more than 30 seconds...
curl https://www.npmjs.org/install.sh | sh

gdamjan

%%% This macro will create a function that converts a record to
%%% a {key, value} list (a proplist)

-define(record_to_list(Record),
    fun(Val) ->
        Fields = record_info(fields, Record),
        [_Tag| Values] = tuple_to_list(Val),
        lists:zip(Fields, Values)
    end
).

utsengar

import org.apache.commons.codec.binary.Base64;


	private String encodeFileToBase64Binary(String fileName)
			throws IOException {

		File file = new File(fileName);
		byte[] bytes = loadFile(file);
		byte[] encoded = Base64.encodeBase64(bytes);
		String encodedString = new String(encoded);

jboner

Latency Comparison Numbers (~2012)
----------------------------------
L1 cache reference                           0.5 ns
Branch mispredict                            5   ns
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 us
Send 1K bytes over 1 Gbps network       10,000   ns       10 us
Read 4K randomly from SSD*             150,000   ns      150 us          ~1GB/sec SSD

killercup

/*
 * I add this to html files generated with pandoc.
 */

html {
  font-size: 100%;
  overflow-y: scroll;
  -webkit-text-size-adjust: 100%;
  -ms-text-size-adjust: 100%;
}

pofider

# .ebextensions/01-ebs.config
commands:
  01clear-if-unmounted:
    command: if ! mount | grep /media/ebs_volume > /dev/nul; then rm -rf /media/ebs_volume; fi
  02attach-volume:
    command: aws ec2 attach-volume --region eu-central-1 --volume-id vol-ddb08e34 --instance-id $(curl -s http://169.254.169.254/latest/meta-data/instance-id) --device /dev/sdh
    ignoreErrors: true
  03wait:
    command: sleep 10
  04trymount:

gaearon

function mapValues(obj, fn) {
  return Object.keys(obj).reduce((result, key) => {
    result[key] = fn(obj[key], key);
    return result;
  }, {});
}

function pick(obj, fn) {
  return Object.keys(obj).reduce((result, key) => {
    if (fn(obj[key])) {

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?

joelittlejohn

(ns dynamic.test
  (:require [clojure.test :refer :all]))

;; This example shows how tests can be generated dynamically, by
;; creating new vars with the correct metadata.

(defn add-test
  "Add a test to the given namespace. The body of the test is given as
  the thunk test-fn. Useful for adding dynamically generated deftests."
  [name ns test-fn & [metadata]]

lilactown

CLJS in AWS Lambda Quick Start

Setup

First, a few dependencies:

1. Leiningen: https://leiningen.org/
2. Node.js & NPM: https://nodejs.org/
3. Serverless: https://serverless.com/
4. An active AWS account: https://aws.amazon.com/