vladfaust

# typed: true

require 'sorbet-runtime'

class A
  extend T::Sig

  sig {params(a: Integer, b: Integer).returns(Integer)}
  def sum(a, b)
    a + b

vladfaust

def sum(a, b)
  # a and b could be anything. The interpreter must firstly find out their
  # exact types and then decide what to do — to either sum numbers or strings
  # or even raise if there is no "+" method for given types
  a + b
end

vladfaust

def hello(who)
  puts "Hello, #{who}!"
end

hello("world") # puts "Hello, world!"

vladfaust

-- Like ZPOPMAX but accept multiple keys and return a single member with maximum score across all the sets.
-- Returns array consisting of the key, member and its score; or nil if all sorted sets are empty.
-- 
-- EVAL ZMPOPMAX 2 keyA keyB
-- > "keyB"
-- > "foo"
-- > "1.5"

local max_member, max_score, max_key = nil, -math.inf, nil
local member, score = nil, nil

vladfaust

Scaling your API with rate limiters

The following are examples of the four types rate limiters discussed in the accompanying blog post. In the examples below I've used pseudocode-like Ruby, so if you're unfamiliar with Ruby you should be able to easily translate this approach to other languages. Complete examples in Ruby are also provided later in this gist.

In most cases you'll want all these examples to be classes, but I've used simple functions here to keep the code samples brief.

Request rate limiter

This uses a basic token bucket algorithm and relies on the fact that Redis scripts execute atomically. No other operations can run between fetching the count and writing the new count.

vladfaust

ch1 = Channel(Nil).new
ch2 = Channel(Nil).new

class Timeout
  def self.new_select_action(span : Time::Span)
    ch = Channel(Nil).new(1)

    spawn do
      sleep(span)
      ch.send(nil)

vladfaust

require "pg"
require "onyx/sql"
require "onyx/rest"

class World
  include Onyx::SQL::Model

  schema worlds do
    pkey id : Int32
    type random_number : Int32, key: "randomnumber"

vladfaust

# https://carc.in/#/r/620u

module Foo
end

module Bar
  include Foo
end

class Baz

vladfaust

steps:
  - command: 
    - "shards install"
    - "tar pczf lib.tar.gz lib/"
    label: "Install shards"
    artifact_paths: "lib.tar.gz"
    plugins:
      - docker#v2.1.0:
          image: "crystallang/crystal:latest"
          always-pull: true

vladfaust

require "../src/onyx-eda/channels/redis"
require "./events"

channel = Onyx::EDA::Channels::Redis.new

channel.subscribe(Events::User) do |event|
  puts "[#{Time.now.to_s("%T:%6N")}] Got a user event, user_id = #{event.user_id}"
end

greeter = ->(event : Events::Users::Created) do