Benchmark between data structures

bench.rb

# frozen_string_literal: true

require 'bundler/inline'
require 'ostruct'

gemfile do
  source "https://rubygems.org"
  gem 'benchmark-ips', require: 'benchmark/ips'
  gem 'benchmark-memory', require: 'benchmark/memory'
end

ValueStruct = Struct.new(:key, :other)

class ValueObject
  attr_reader :key, :other

  def initialize(key, other)
    @key = key
    @other = other
  end
end

class ValueObject2
  attr_reader :key, :other

  def initialize(key:, other:)
    @key = key
    @other = other
  end
end

Benchmark.ips do |x|
  x.config(time: 5, warmup: 2)

  x.report("hash") { h = { key: "value", other: "other value" }; h[:other] }
  x.report("ostruct") { o = OpenStruct.new(key: "value", other: "other value"); o.other }
  x.report("struct") { s = ValueStruct.new(key: "value", other: "other value"); s.other }
  x.report("class") { s = ValueObject.new("value", "other value"); s.other }
  x.report("kargs-class") { s = ValueObject2.new(key: "value", other: "other value"); s.other }

  x.compare!
end

Benchmark.memory do |x|
  x.report("hash") { h = { key: "value", other: "other value" }; h[:other] }
  x.report("ostruct") { o = OpenStruct.new(key: "value", other: "other value"); o.other }
  x.report("struct") { s = ValueStruct.new(key: "value", other: "other value"); s.other }
  x.report("class") { s = ValueObject.new("value", "other value"); s.other }
  x.report("kargs-class") { s = ValueObject2.new(key: "value", other: "other value"); s.other }

  x.compare!
end

results.txt

####################################################################################################
Iteration per second
####################################################################################################

Warming up --------------------------------------
                hash   110.273k i/100ms
             ostruct    13.676k i/100ms
              struct    92.467k i/100ms
               class   188.862k i/100ms
         kargs-class    56.304k i/100ms
Calculating -------------------------------------
                hash      1.626M (± 5.0%) i/s -      8.160M in   5.032514s
             ostruct    145.801k (± 3.5%) i/s -    738.504k in   5.072197s
              struct      1.243M (± 7.0%) i/s -      6.195M in   5.011539s
               class      3.742M (± 7.4%) i/s -     18.697M in   5.033734s
         kargs-class    693.452k (± 6.1%) i/s -      3.491M in   5.058219s

Comparison:
               class:  3741830.7 i/s
                hash:  1625872.7 i/s - 2.30x  slower
              struct:  1243438.7 i/s - 3.01x  slower
         kargs-class:   693451.7 i/s - 5.40x  slower
             ostruct:   145801.1 i/s - 25.66x  slower

####################################################################################################
Memory usage (Object allocations)
####################################################################################################

Calculating -------------------------------------
                hash   192.000  memsize (     0.000  retained)
                         1.000  objects (     0.000  retained)
                         0.000  strings (     0.000  retained)
             ostruct     1.384k memsize (     0.000  retained)
                        11.000  objects (     0.000  retained)
                         2.000  strings (     0.000  retained)
              struct   232.000  memsize (     0.000  retained)
                         2.000  objects (     0.000  retained)
                         0.000  strings (     0.000  retained)
               class    40.000  memsize (     0.000  retained)
                         1.000  objects (     0.000  retained)
                         0.000  strings (     0.000  retained)
         kargs-class   424.000  memsize (     0.000  retained)
                         3.000  objects (     0.000  retained)
                         0.000  strings (     0.000  retained)

Comparison:
               class:         40 allocated
                hash:        192 allocated - 4.80x more
              struct:        232 allocated - 5.80x more
         kargs-class:        424 allocated - 10.60x more
             ostruct:       1384 allocated - 34.60x more