benchmark.rb

require 'benchmark/ips'
require 'active_support/core_ext'
require 'jbuilder'
require 'rabl'
require 'oj'

Benchmark.ips do |benchmark|
  struct = Struct.new(:name, :birthyear, :bio, :url)
  @author = struct.new("Rolf", 1920, "Software developer", "http://example.com/")
  @authors = Array.new(10, @author)

  # for jbuilder
  @author.instance_eval { undef map }

  # for rabl
  @scope = Object.new
  @scope.instance_variable_set :@author, @author
  @template_for_single_object = %{
    object @author => :author
    attribute :name, :birthyear, :bio, :url
  }

  @scope.instance_variable_set :@authors, @authors
  @template_for_collection = %{
    collection @authors => :authors
    attributes :name, :birthyear, :bio, :url
  }

  benchmark.report "Jbuilder(single obj)" do
    Jbuilder.encode do |json|
      json.author @author, :name, :birthyear, :bio, :url
    end
  end

  benchmark.report "Rabl(single obj)" do
    Rabl::Engine.new(@template_for_single_object).render(@scope, {})
  end

  benchmark.report "Jbuilder(collection)" do
    Jbuilder.encode do |json|
      json.authors @authors do |author|
        json.author author, :name, :birthyear, :bio, :url
      end
    end
  end

  benchmark.report "Rabl(collection)" do
    Rabl::Engine.new(@template_for_collection).render(@scope, {})
  end
end

Gemfile

source 'https://rubygems.org'

gem 'benchmark-ips'
gem 'activesupport'
gem 'jbuilder'
gem 'rabl'
gem 'oj'

Gemfile.lock

GEM
  remote: https://rubygems.org/
  specs:
    activesupport (4.0.2)
      i18n (~> 0.6, >= 0.6.4)
      minitest (~> 4.2)
      multi_json (~> 1.3)
      thread_safe (~> 0.1)
      tzinfo (~> 0.3.37)
    atomic (1.1.14)
    benchmark-ips (1.2.0)
    i18n (0.6.9)
    jbuilder (2.0.2)
      activesupport (>= 3.0.0)
      multi_json (>= 1.2.0)
    minitest (4.7.5)
    multi_json (1.8.4)
    oj (2.5.4)
    rabl (0.9.3)
      activesupport (>= 2.3.14)
    thread_safe (0.1.3)
      atomic
    tzinfo (0.3.38)

PLATFORMS
  ruby

DEPENDENCIES
  activesupport
  benchmark-ips
  jbuilder
  oj
  rabl