jcasimir

Managing the Flash

HTTP is a stateless protocol. The server, generally speaking, has no idea if request number 243 came from the same user as request number 236. That's beautiful and, at the same time, annoying.

In the context of web applications we frequently want to persist state between requests. That might mean something like a shopping cart that follows a user through the online store, but it can be as simple as a status message.

In modern applications users expect feedback. They click a delete link and they expect to no just see the item disappear, they'll expect a "Item Deleted" message. In Rails we handle these messages using the flash.

Flash as Hash

tonyc

Using strace and lsof to debug blocked processes

You can use strace on a specific pid to figure out what a specific process is doing, e.g.:

strace -fp <pid>

You might see something like:

select(9, [3 5 8], [], [], {0, 999999}) = 0 (Timeout)

klapaucius

Строгость и нищета списков.

Map и структурная рекурсия.

Применить функцию к каждому элементу списка - это просто:

GHC/Base.lhs

map _ []     = []
map f (x:xs) = f x : map f xs

fogus

; Ruby has an awesome feature -- string interpolation. Read about it on the internet.
; On the other hand, Clojure only has cumbersome Java string formatting, which can not be
; used without pain after you've tried Ruby.

; So here's this simple macro that basically allows you to do most things you could do
; with Ruby string interpolation in Clojure.

(ns eis.stuff
  (:require [clojure.string]))

chetan

YARD CHEATSHEET http://yardoc.org

May 2020 - updated fork: https://gist.github.com/phansch/db18a595d2f5f1ef16646af72fe1fb0e

cribbed from http://pastebin.com/xgzeAmBn

Templates to remind you of the options and formatting for the different types of objects you might want to document using YARD.

Modules

henrik

tmux cheatsheet

As configured in my dotfiles.

start new:

tmux

start new with session name:

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

roberto

<% flash.each do |type, message| %>
  <div class="alert <%= bootstrap_class_for(type) %> fade in">
    <button class="close" data-dismiss="alert">×</button>
    <%= message %>
  </div>
<% end %>

justinko

require 'mongoid'
require 'pp'

Mongoid.configure do |config|
  config.allow_dynamic_fields = false
  config.connect_to 'mongo_test', { consistency: :strong }
end

Mongoid.default_session.drop

gevans

require 'openssl'

key = OpenSSL::PKey::RSA.new(2048)
p encrypted_string = key.public_encrypt('my plaintext string', OpenSSL::PKey::RSA::PKCS1_OAEP_PADDING)
p decrypted_string = key.private_decrypt(encrypted_string, OpenSSL::PKey::RSA::PKCS1_OAEP_PADDING)