kirs

class Node
  attr_accessor :edges, :jobs, :id

  def initialize(id, arrivals_per_tick)
    @id = id
    @jobs = 0.0
    @tick = 0
    @edges = []
    @arrivals_per_tick = arrivals_per_tick
  end

kirs

apt update
apt upgrade
apt install build-essential
apt install pkg-config
apt install libnet-dev python-yaml libaio-dev
apt install libprotobuf-dev libprotobuf-c0-dev protobuf-c-compiler protobuf-compiler python-protobuf libnl-3-dev libcap-dev python-future

# criu install
curl -O -sSL http://download.openvz.org/criu/criu-3.10.tar.bz2
tar xjf criu-3.10.tar.bz2 

kirs

# Updated for Ruby 2.3
string_t = None

def get_rstring(addr):
  s = addr.cast(string_t.pointer())
  if s['basic']['flags'] & (1 << 13):
    return s['as']['heap']['ptr'].string()
  else:
    return s['as']['ary'].string()

kirs

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)

kirs

Legacy Database

User.first.name # => "Renan"

After put encrypted_coder.rb and crypt.rb

User.first.name # => OpenSSL::Cipher::CipherError: bad decrypt

kirs

#!/bin/bash
# Pushes the current branch to origin and opens a tiny tmux split to track
# the CI status. Upon completion, speaks the status aloud using `say`.
set -e

if [ "$1" != "--wait" ]; then
  git push -u origin HEAD
  tmux split-window -dv -l 2 "'$0' --wait"
else
  ref="$(git rev-parse -q HEAD)"

kirs

require "rubocop"

module RuboCop
  module Cop
    module Lint
      # This cop checks bad use of the Minitest `assert` method
      #
      # `assert` method's second argument is the error message when the
      # first argument evals to false.
      #

kirs

Опции bash для разработки

Разрабатывайте скрипты с опциями set -eu

• set -e - падать на ошибках
• set -u - считать ошибкой обращение к неопределенной переменной

Профиты

• максимально быстрое выявление скрытых ошибок в коде.
• не надо самому писать многие проверки значений.
• Это сделает shell-код похожим на нормальный язык программирования, а не на набор последовательно выполняющихся команд, которым на всё пофиг.

kirs

Step 0:

Get Homebrew installed on your mac if you don't already have it

Step 1:

Install highlight. "brew install highlight". (This brings down Lua and Boost as well)

Step 2:

kirs

class MessageImageWorker
  @queue = :message_image_queue
  def self.perform(message_id, image_path)
    MessageImage.create!(message_id: message_id, image: image_path)
  end
end