OpenStruct vs Struct vs Hash performance

open_struct_struct_hash.rb

require 'benchmark'
require 'ostruct'

REP = 1000000

User = Struct.new(:name, :age)

USER = "User".freeze
AGE = 21
HASH = {:name => USER, :age => AGE}.freeze

Benchmark.bm 20 do |x|
  x.report 'OpenStruct slow' do
    REP.times do |index|
       OpenStruct.new(:name => "User", :age => 21)
    end
  end

  x.report 'OpenStruct fast' do
    REP.times do |index|
       OpenStruct.new(HASH)
    end
  end

  x.report 'Struct slow' do
    REP.times do |index|
       User.new("User", 21)
    end
  end

  x.report 'Struct fast' do
    REP.times do |index|
       User.new(USER, AGE)
    end
  end

  x.report 'Hash slow' do
    REP.times do |index|
      {:name => 'User', :age => 21}
    end
  end

  x.report 'Hash fast' do
    REP.times do |index|
      {:name => USER, :age => AGE}
    end
  end
end

output

                           user     system      total        real
OpenStruct slow        8.150000   0.000000   8.150000 (  8.153797)
OpenStruct fast        7.980000   0.000000   7.980000 (  7.983929)
Struct slow            0.270000   0.000000   0.270000 (  0.268514)
Struct fast            0.200000   0.000000   0.200000 (  0.196950)
Hash slow              0.580000   0.000000   0.580000 (  0.584160)
Hash fast              0.460000   0.000000   0.460000 (  0.458502)