Delegator vs Inheritance benchmark

delegator_vs_inheritance.rb

#!/usr/bin/env ruby

require 'bundler/inline'
require 'securerandom'
require 'delegate'

gemfile(true) do
  source 'https://rubygems.org'
  gem 'rails'
  gem 'active_model_serializers', github: "runtastic/active_model_serializers"
  gem 'activesupport', require: 'active_support/inflector'
  gem 'benchmark-ips', require: 'benchmark/ips'
end

module ActiveModel
  class Serializer
    class Adapter
      def cache_check(serializer)
        yield
      end
    end
  end
end

class Model
  def initialize(hash = {})
    @attributes = hash
  end

  def read_attribute_for_serialization(attr)
    @attributes[attr]
  end
end

N = 50
S = Set.new((0..N).map { SecureRandom.hex })

puts "With #{S.size} attributes"

Organizer = Class.new(Model)

class OrganizerSerializer < ActiveModel::Serializer
  S.each do |attr|
    attribute attr
  end
end
class TypePluralizer < SimpleDelegator
  def type
    object.class.name.pluralize
  end
end
class SerializerTypePluralizer < DelegateClass(ActiveModel::Serializer)
  def type
    object.class.name.pluralize
  end
end

class BaseSerializer < ActiveModel::Serializer
  def type
    object.class.name.pluralize
  end
end

class PluralTypeOrganizerSerializer < BaseSerializer
  S.each do |attr|
    attribute attr
  end
end

organizer_attrs = S.each_with_object({}) do |attr_name, attrs|
  attrs[attr_name] = SecureRandom.hex
end
OBJECT = Organizer.new(organizer_attrs)

Benchmark.ips do |x|
  x.config(time: 15)

  #  x.report("bare") do
  #    serializer = OrganizerSerializer.new(OBJECT)
  #    ActiveModel::Serializer::Adapter.create(serializer).to_json
  #  end

  x.report("with inheritance") do
    serializer = PluralTypeOrganizerSerializer.new(OBJECT)
    ActiveModel::Serializer::Adapter.create(serializer).to_json
  end

  x.report("SimpleDelegator") do
    serializer = OrganizerSerializer.new(OBJECT)
    serializer = TypePluralizer.new(serializer)
    ActiveModel::Serializer::Adapter.create(serializer).to_json
  end

  x.report("DelegatorClass") do
    serializer = OrganizerSerializer.new(OBJECT)
    serializer = SerializerTypePluralizer.new(serializer)
    ActiveModel::Serializer::Adapter.create(serializer).to_json
  end

  x.compare!
end

result.txt

$ ./delegator_vs_inheritance.rb # using ruby 2.2

With 51 attributes
Calculating -------------------------------------
    with inheritance   131.000  i/100ms
     SimpleDelegator   131.000  i/100ms
      DelegatorClass   124.000  i/100ms
-------------------------------------------------
    with inheritance      1.324k (± 3.5%) i/s -     19.912k
     SimpleDelegator      1.326k (± 3.2%) i/s -     19.912k
      DelegatorClass      1.328k (± 2.8%) i/s -     19.964k

Comparison:
      DelegatorClass:     1328.5 i/s
     SimpleDelegator:     1326.3 i/s - 1.00x slower
    with inheritance:     1323.7 i/s - 1.00x slower

$ ./delegator_vs_inheritance.rb # using jruby 1.7.19
With 51 attributes
Calculating -------------------------------------
    with inheritance    98.000  i/100ms
     SimpleDelegator   166.000  i/100ms
      DelegatorClass   192.000  i/100ms
-------------------------------------------------
    with inheritance      2.652k (±13.2%) i/s -     38.906k
     SimpleDelegator      2.782k (± 9.5%) i/s -     41.334k
      DelegatorClass      2.840k (± 6.9%) i/s -     42.432k

Comparison:
      DelegatorClass:     2840.1 i/s
     SimpleDelegator:     2781.9 i/s - 1.02x slower
    with inheritance:     2652.4 i/s - 1.07x slower