proc vs. direct method call

benchmark.rb

require 'benchmark'
require 'json'

HASH = {'a'=>1, 'b'=>[1,2,3]}

class Roda
  class << self
    attr_accessor :opts
  end
end

a = Proc.new { HASH.to_json }
class A
  def self.a
    HASH.to_json
  end
end

Roda.opts = {}
Roda.opts[:json_result_serializer] = a
Roda.opts[:json_result_serializer_class] = A

n = 100000
Benchmark.bm do |x|
  x.report('proc')  { for i in 1..n; Roda.opts[:json_result_serializer].call end }
  x.report('class') { for i in 1..n; Roda.opts[:json_result_serializer_class].a end }
end


#        user     system      total        real
# proc  0.330000   0.000000   0.330000 (  0.331962)
# class  0.310000   0.000000   0.310000 (  0.311764)


#        user     system      total        real
# proc  0.350000   0.000000   0.350000 (  0.358796)
# class  0.350000   0.000000   0.350000 (  0.342676)

# 0.331962 / 0.311764
# => 1.0647861844215496


# 0.358796 / 0.342676
# => 1.047041520269876

## proc seems to be around 5% slower. It probably does not matter, you are right