Benchmark the new Ruby shape introduced in ruby 3.2

object_shape_benchmark.rb

class TestObjectShapeGetCheck
  def initialize
    @var0 = 0
    @var1 = 1
    @var2 = 2
    @var3 = 3
    @var4 = 4
    @var5 = 5
    @var6 = 6
    @var7 = 7
    @var8 = 8
    @var9 = 9
    @var10 = 10
    @var11 = 11
    @var12 = 12
    @var13 = 13
    @var14 = 14
    @var15 = 15
    @var16 = 16
    @var17 = 17
    @var18 = 18
    @var19 = 19
    @var20 = 20
    @var21 = 21
    @var22 = 22
    @var23 = 23
    @var24 = 24
    @var25 = 25
    @var26 = 26
    @var27 = 27
    @var28 = 28
    @var29 = 29
    @var30 = 30
    @var31 = 31
    @var32 = 32
    @var33 = 33
    @var34 = 34
    @var35 = 35
    @var36 = 36
    @var37 = 37
    @var38 = 38
    @var39 = 39
    @var40 = 40
    @var41 = 41
    @var42 = 42
    @var43 = 43
    @var44 = 44
    @var45 = 45
    @var46 = 46
    @var47 = 47
    @var48 = 48
    @var49 = 49
    @var50 = 50
    @var51 = 51
    @var52 = 52
    @var53 = 53
    @var54 = 54
    @var55 = 55
    @var56 = 56
    @var57 = 57
    @var58 = 58
    @var59 = 59
    @var60 = 60
    @var61 = 61
    @var62 = 62
    @var63 = 63
    @var64 = 64
    @var65 = 65
    @var66 = 66
    @var67 = 67
    @var68 = 68
    @var69 = 69
    @var70 = 70
    @var71 = 71
    @var72 = 72
    @var73 = 73
    @var74 = 74
    @var75 = 75
    @var76 = 76
    @var77 = 77
    @var78 = 78
    @var79 = 79
    @var80 = 80
    @var81 = 81
    @var82 = 82
    @var83 = 83
    @var84 = 84
    @var85 = 85
    @var86 = 86
    @var87 = 87
    @var88 = 88
    @var89 = 89
    @var90 = 90
    @var91 = 91
    @var92 = 92
    @var93 = 93
    @var94 = 94
    @var95 = 95
    @var96 = 96
    @var97 = 97
    @var98 = 98
    @var99 = 99
  end

  def test
    # Check the access and the cache performance
    100.times do
      100.times.sum { |i| instance_variable_get("@var#{i}") }
    end
  end
end

class TestObjectShapeWriteCheck
  def initialize(number)
    @number = number

    # Set lots of instance variables to check the performance
    number.times {|i| instance_variable_set("@var#{i}", 1) }
  end

  def test
    @number.times.sum { |i| instance_variable_get("@var#{i}") }
  end
end

require 'benchmark'
puts "Benchmark Object Shape - Ruby version: #{RUBY_VERSION}"
Benchmark.bm do |x|
  x.report("Test Get") do
    100.times { TestObjectShapeGetCheck.new.test }
  end
  x.report("Test Write") do
    100.times { TestObjectShapeWriteCheck.new(10_000).test }
  end
end

Interpreters compiled on an arm64-darwin23 system

Ruby 2.6

Benchmark Object Shape - Ruby version: 2.6.10
       user     system      total        real
Test Get  0.172598   0.001317   0.173915 (  0.173993)
Test Write  0.316040   0.002060   0.318100 (  0.318193)

Ruby 2.7

Benchmark Object Shape - Ruby version: 2.7.8
       user     system      total        real
Test Get  0.149773   0.000508   0.150281 (  0.150283)
Test Write  0.297791   0.002364   0.300155 (  0.300467)

Ruby 3.0

Benchmark Object Shape - Ruby version: 3.0.4
       user     system      total        real
Test Get  0.159921   0.000519   0.160440 (  0.160455)
Test Write  0.313218   0.002063   0.315281 (  0.315355)

Ruby 3.1

Benchmark Object Shape - Ruby version: 3.1.4
       user     system      total        real
Test Get  0.155305   0.000858   0.156163 (  0.156332)
Test Write  0.306863   0.003154   0.310017 (  0.310303)

Ruby 3.2

Benchmark Object Shape - Ruby version: 3.2.5
       user     system      total        real
Test Get  0.246723   0.000768   0.247491 (  0.247523)
Test Write 19.333101   0.056330  19.389431 ( 19.426760)

^ 19.333101

Ruby 3.3

Benchmark Object Shape - Ruby version: 3.3.6
       user     system      total        real
Test Get  0.205304   0.000885   0.206189 (  0.206241)
Test Write 13.159885   0.036833  13.196718 ( 13.213467)

^ 13.159885

Ruby 3.4.0dev (2024-11-27T17:12:23Z master 0af2eafc59) +PRISM

Benchmark Object Shape - Ruby version: 3.4.0
                user     system      total        real
Test Get    0.218310   0.001404   0.219714 (  0.220102)
Test Write  0.452340   0.004006   0.456346 (  0.456629)