Update to https://www.honeybadger.io/blog/how-openstruct-and-hashes-can-kill-performance/

hash_performance.rb

# Response to:
# http://blog.honeybadger.io/how-openstruct-and-hashes-can-kill-performance/
#
# It's not faire to use `Hash.new.merge(data)` if you can `Hash[data]`.
# `Hash[data]` is way faster! Lets compare!
#
# Read more: http://ruby-doc.org/core-2.2.0/Hash.html#method-c-5B-5D
#
# [UPDATE]
#
# * Disable GC for each report

require 'benchmark/ips'
require 'ostruct'


# Enable and start GC before each job run. Disable GC afterwards.
#
# Inspired by https://www.omniref.com/ruby/2.2.1/symbols/Benchmark/bm?#annotation=4095926&line=182
class GCSuite
  def warming(*)
    run_gc
  end

  def running(*)
    run_gc
  end

  def warmup_stats(*)
  end

  def add_report(*)
  end

  private

  def run_gc
    GC.enable
    GC.start
    GC.disable
  end
end

suite = GCSuite.new


data = { x: 100, y: 200 }


PointStruct = Struct.new(:x, :y)
PointKeywordStruct = Struct.new(:x, :y, keyword_init: true)

class FakedPointStruct
  attr_accessor :x, :y
  def initialize(x, y)
    @x = x
    @y = y
  end
end

class PointClassFetch
  attr_accessor :x, :y
  def initialize(args)
    @x = args.fetch(:x) # NOTE: Hash#fetch -> performance impact
    @y = args.fetch(:y)
  end
end

class PointClassKeyword
  attr_accessor :x, :y
  def initialize(x:, y:)
    @x = x
    @y = y
  end
end

puts "\n\nINITIALIZATION =========="

Benchmark.ips do |x|
  x.json! 'INITIALIZATION.json'
  x.config(suite: suite)

  # Create Objects as a reference value
  x.report("Object.new") { Object.new }

  x.report("FakedPointStruct") { FakedPointStruct.new(100, 200) }
  x.report("PointStruct") { PointStruct.new(100, 200) }
  x.report("PointKeywordStruct") { PointKeywordStruct.new(data) }
  x.report("Hash[]") { Hash[data] }
  x.report("PointClassFetch") { PointClassFetch.new(data) }
  x.report("PointClassKeyword") { PointClassKeyword.new(data) }
  x.report("Hash#merge") { Hash.new.merge(data) }
  x.report("OpenStruct") { OpenStruct.new(data) }

  x.compare!
end

puts "\n\nREAD =========="

point_struct = PointStruct.new(100, 200)
point_keyword_struct = PointKeywordStruct.new(data)
point_class_fetch = PointClassFetch.new(data)
point_class_keyword = PointClassKeyword.new(data)
point_hash = Hash[data]
point_open_struct = OpenStruct.new(data)

Benchmark.ips do |x|
  x.json! 'READ.json'
  x.config(suite: suite)

  x.report("PointStruct") { point_struct.x }
  x.report("PointKeywordStruct") { point_keyword_struct.x }
  x.report("PointClassFetch") {  point_class_fetch.x }
  x.report("PointClassKeyword") {  point_class_keyword.x }
  x.report("Hash#fetch") { point_hash.fetch(:x) }
  x.report("Hash#[]") { point_hash[:x] }
  x.report("OpenStruct") {  point_open_struct.x }

  x.compare!
end


puts "\n\nWRITE =========="

Benchmark.ips do |x|
  x.json! 'WRITE.json'
  x.config(suite: suite)

  x.report("PointStruct") { point_struct.x = 1 }
  x.report("PointKeywordStruct") { point_keyword_struct.x = 1 }
  x.report("PointClassFetch") {  point_class_fetch.x = 1 }
  x.report("PointClassKeyword") {  point_class_keyword.x = 1 }
  x.report("Hash") { point_hash[:x] = 1 }
  x.report("OpenStruct") {  point_open_struct.x = 1 }

  x.compare!
end


# INITIALIZATION ==========
# Calculating -------------------------------------
#           Object.new   232.512k i/100ms
#     FakedPointStruct   208.718k i/100ms
#          PointStruct   213.914k i/100ms
#   PointKeywordStruct   175.460k i/100ms
#               Hash[]   183.239k i/100ms
#      PointClassFetch   182.943k i/100ms
#    PointClassKeyword   131.129k i/100ms
#           Hash#merge   154.966k i/100ms
#           OpenStruct   117.413k i/100ms
# -------------------------------------------------
#           Object.new      7.677M (±16.1%) i/s -     37.667M
#     FakedPointStruct      5.919M (±12.3%) i/s -     29.221M
#          PointStruct      5.801M (±11.4%) i/s -     28.664M
#   PointKeywordStruct      4.125M (± 8.9%) i/s -     20.529M
#               Hash[]      4.421M (±17.4%) i/s -     21.622M
#      PointClassFetch      4.810M (± 7.0%) i/s -     23.966M
#    PointClassKeyword      2.308M (±10.0%) i/s -     11.539M
#           Hash#merge      2.963M (±14.7%) i/s -     14.567M
#           OpenStruct      1.975M (± 6.6%) i/s -      9.863M

# Comparison:
#           Object.new:  7677097.4 i/s
#     FakedPointStruct:  5918849.2 i/s - 1.30x slower
#          PointStruct:  5801076.3 i/s - 1.32x slower
#      PointClassFetch:  4809859.9 i/s - 1.60x slower
#               Hash[]:  4420989.7 i/s - 1.74x slower
#   PointKeywordStruct:  4125176.9 i/s - 1.86x slower
#           Hash#merge:  2962687.0 i/s - 2.59x slower
#    PointClassKeyword:  2307777.5 i/s - 3.33x slower
#           OpenStruct:  1974635.6 i/s - 3.89x slower



# READ ==========
# Calculating -------------------------------------
#          PointStruct   275.075k i/100ms
#   PointKeywordStruct   284.487k i/100ms
#      PointClassFetch   284.814k i/100ms
#    PointClassKeyword   274.721k i/100ms
#           Hash#fetch   262.639k i/100ms
#              Hash#[]   282.053k i/100ms
#           OpenStruct   244.214k i/100ms
# -------------------------------------------------
#          PointStruct     19.828M (± 5.1%) i/s -     99.027M
#   PointKeywordStruct     20.033M (± 5.2%) i/s -    100.139M
#      PointClassFetch     23.465M (± 3.4%) i/s -    117.343M
#    PointClassKeyword     22.488M (± 2.2%) i/s -    112.636M
#           Hash#fetch     16.465M (± 2.0%) i/s -     82.469M
#              Hash#[]     22.144M (± 3.0%) i/s -    110.847M
#           OpenStruct     10.675M (± 3.5%) i/s -     53.483M

# Comparison:
#      PointClassFetch: 23465137.5 i/s
#    PointClassKeyword: 22488166.1 i/s - 1.04x slower
#              Hash#[]: 22143937.7 i/s - 1.06x slower
#   PointKeywordStruct: 20033487.9 i/s - 1.17x slower
#          PointStruct: 19827584.5 i/s - 1.18x slower
#           Hash#fetch: 16465062.4 i/s - 1.43x slower
#           OpenStruct: 10674642.1 i/s - 2.20x slower



# WRITE ==========
# Calculating -------------------------------------
#          PointStruct   263.792k i/100ms
#   PointKeywordStruct   265.678k i/100ms
#      PointClassFetch   269.824k i/100ms
#    PointClassKeyword   282.345k i/100ms
#                 Hash   267.091k i/100ms
#           OpenStruct   224.234k i/100ms
# -------------------------------------------------
#          PointStruct     17.523M (± 2.3%) i/s -     87.579M
#   PointKeywordStruct     17.653M (± 3.0%) i/s -     88.205M
#      PointClassFetch     21.269M (± 4.6%) i/s -    106.041M
#    PointClassKeyword     21.139M (± 3.7%) i/s -    105.597M
#                 Hash     16.899M (± 4.7%) i/s -     84.401M
#           OpenStruct      7.053M (± 5.8%) i/s -     35.205M

# Comparison:
#      PointClassFetch: 21268766.9 i/s
#    PointClassKeyword: 21138642.2 i/s - 1.01x slower
#   PointKeywordStruct: 17652879.3 i/s - 1.20x slower
#          PointStruct: 17522748.0 i/s - 1.21x slower
#                 Hash: 16899040.6 i/s - 1.26x slower
#           OpenStruct:  7053426.1 i/s - 3.02x slower