OpenStruct vs Struct vs Hash in Ruby

bench.rb

require 'benchmark/ips'
require 'ostruct'


# Enable and start GC before each job run. Disable GC afterwards.
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)

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

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


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

Benchmark.ips do |x|
  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("Hash[]") { Hash[data] }
  x.report("PointClass") { PointClass.new(data) }
  x.report("Hash#merge") { Hash.new.merge(data) }
  x.report("OpenStruct") { OpenStruct.new(data) }
end

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

point_struct = PointStruct.new(100, 200)
point_class = PointClass.new(data)
point_hash = Hash[data]
point_open_struct = OpenStruct.new(data)

Benchmark.ips do |x|
  x.config(suite: suite)

  x.report("PointStruct") { point_struct.x }
  x.report("PointClass") {  point_class.x }
  x.report("Hash#fetch") { point_hash.fetch(:x) }
  x.report("Hash#[]") { point_hash[:x] }
  x.report("OpenStruct") {  point_open_struct.x }
end


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

Benchmark.ips do |x|
  x.config(suite: suite)

  x.report("PointStruct") { point_struct.x = 1 }
  x.report("PointClass") {  point_class.x = 1 }
  x.report("Hash") { point_hash[:x] = 1 }
  x.report("OpenStruct") {  point_open_struct.x = 1 }
end

# INITIALIZATION ==========
# Warming up --------------------------------------
#           Object.new   577.732k i/100ms
#     FakedPointStruct   464.942k i/100ms
#          PointStruct   488.484k i/100ms
#               Hash[]   387.569k i/100ms
#           PointClass   347.606k i/100ms
#           Hash#merge   227.653k i/100ms
#           OpenStruct   151.441k i/100ms
# Calculating -------------------------------------
#           Object.new      5.297M (±15.1%) i/s -     25.998M in   5.036946s
#     FakedPointStruct      4.210M (± 9.2%) i/s -     21.387M in   5.124131s
#          PointStruct      4.351M (±11.8%) i/s -     21.493M in   5.024872s
#               Hash[]      3.412M (±20.6%) i/s -     16.665M in   5.080603s
#           PointClass      3.184M (± 8.0%) i/s -     15.990M in   5.058015s
#           Hash#merge      2.149M (±17.2%) i/s -     10.472M in   5.007291s
#           OpenStruct      1.496M (± 6.1%) i/s -      7.572M in   5.078252s


# READ ==========
# Warming up --------------------------------------
#          PointStruct     1.520M i/100ms
#           PointClass     1.798M i/100ms
#           Hash#fetch     1.232M i/100ms
#              Hash#[]     1.393M i/100ms
#           OpenStruct   646.764k i/100ms
# Calculating -------------------------------------
#          PointStruct     13.659M (±11.9%) i/s -     68.401M in   5.103649s
#           PointClass     16.637M (± 6.1%) i/s -     84.504M in   5.100355s
#           Hash#fetch     12.108M (± 6.4%) i/s -     60.387M in   5.013311s
#              Hash#[]     16.935M (± 2.2%) i/s -     84.955M in   5.019082s
#           OpenStruct      7.410M (±13.4%) i/s -     36.219M in   5.012097s


# WRITE ==========
# Warming up --------------------------------------
#          PointStruct     1.090M i/100ms
#           PointClass     1.493M i/100ms
#                 Hash     1.296M i/100ms
#           OpenStruct   520.228k i/100ms
# Calculating -------------------------------------
#          PointStruct     11.665M (±12.3%) i/s -     57.782M in   5.082646s
#           PointClass     16.112M (± 3.3%) i/s -     80.636M in   5.010430s
#                 Hash     11.975M (±12.1%) i/s -     59.606M in   5.095005s
#           OpenStruct      4.495M (±14.8%) i/s -     22.370M in   5.127749s