gistfile1.rb

require 'benchmark/ips'

class FakeDimension
  def initialize
    @margin_start = 10
    @margin_start_relative = false
  end

  def relative?(result)
    result.is_a?(Float) && result <= 1
  end

  def calculate_relative(result)
    (result * 100).to_i
  end

  define_method :full_meta do
    instance_variable_name = '@' + :full_meta.to_s
    value = instance_variable_get(instance_variable_name) || 0
    value = calculate_relative value if relative? value
    value
  end

  IVAR_NAME = "@margin_start"
  define_method :hoist_ivar_name do
    value = instance_variable_get(IVAR_NAME) || 0
    value = calculate_relative value if relative? value
    value
  end

  define_method :direct_ivar do
    value = @margin_start
    value = calculate_relative value if relative? value
    value
  end

  define_method :memoize_relative_flag do
    value = @margin_start
    value = calculate_relative value if @margin_start_relative
    value
  end

  eval <<-CODE
  def full_string
    value = @margin_start
    value = calculate_relative value if @margin_start_relative
    value
  end
  CODE

  def full_direct
    value = @margin_start
    value = calculate_relative value if @margin_start_relative
    value
  end
end

Benchmark.ips do |benchmark|
  dim = FakeDimension.new
  benchmark.report("full_meta")             { dim.full_meta }
  benchmark.report("hoist_ivar_name")       { dim.hoist_ivar_name }
  benchmark.report("direct_ivar")           { dim.direct_ivar }
  benchmark.report("memoize_relative_flag") { dim.memoize_relative_flag }
  benchmark.report("full_string")           { dim.full_string }
  benchmark.report("full_direct")           { dim.full_direct }
  benchmark.compare!
end