Benchmarking Net::HTTPHeader#capitalize

benchmark.rb

# frozen_string_literal: true
require 'benchmark/ips'
require 'benchmark/memory'

def original(name)
  name.to_s.split(/-/).map {|s| s.capitalize }.join('-')
end

def string(name)
  name.to_s.split('-').map {|s| s.capitalize }.join('-')
end

def each_capitalize_bang(name)
  name.to_s.split('-').each {|s| s.capitalize! }.join('-')
end

def capitalize_bang(name)
  name.to_s.split('-').map {|s| s.capitalize! || s }.join('-')
end

def map_bang(name)
  name.to_s.split('-').map! {|s| s.capitalize }.join('-')
end

def map_bang_capitalize_bang_or(name)
  name.to_s.split('-').map! {|s| s.capitalize! || s }.join('-')
end

def map_bang_capitalize_bang_semicolon(name)
  name.to_s.split('-').map! {|s| s.capitalize!; s }.join('-')
end

def gsub(name)
  name.to_s.gsub(/([^-]+)/) {|s| s.capitalize }
end

def gsub_alt(name)
  name.to_s.gsub(/(\A|(?<=[\^\-]))([a-z])/) do |c|
    c.upcase!
    c
  end
end

lowercase_input_dash = "sec-ch-ua-full-version-list"

report = lambda do |x|
  x.report "original" do
    original(lowercase_input_dash)
  end

  x.report "string split" do
    string(lowercase_input_dash)
  end

  x.report "each capitalize!" do
    each_capitalize_bang(lowercase_input_dash)
  end

  x.report "capitalize!" do
    capitalize_bang(lowercase_input_dash)
  end

  x.report "map!" do
    map_bang(lowercase_input_dash)
  end

  x.report "map! with capitalize! & logical or" do
    map_bang_capitalize_bang_or(lowercase_input_dash)
  end

  x.report "map! capitalize! & two statements" do
    map_bang_capitalize_bang_semicolon(lowercase_input_dash)
  end

  x.report "gsub" do
    gsub(lowercase_input_dash)
  end

  x.report "gsub alt" do
    gsub_alt(lowercase_input_dash)
  end

  x.compare!
end

Benchmark.ips(&report)
Benchmark.memory(&report)

gistfile1.txt

Warming up --------------------------------------
            original    41.691k i/100ms
        string split    65.574k i/100ms
    each capitalize!    65.062k i/100ms
         capitalize!    62.557k i/100ms
                map!    66.773k i/100ms
map! with capitalize! & logical or
                        56.690k i/100ms
map! capitalize! & two statements
                        60.292k i/100ms
                gsub    35.582k i/100ms
            gsub alt    37.382k i/100ms
Calculating -------------------------------------
            original    421.623k (± 0.9%) i/s -      2.126M in   5.043411s
        string split    674.835k (± 0.9%) i/s -      3.410M in   5.053282s
    each capitalize!    656.591k (± 1.0%) i/s -      3.318M in   5.054098s
         capitalize!    632.284k (± 1.1%) i/s -      3.190M in   5.046440s
                map!    670.843k (± 1.3%) i/s -      3.405M in   5.077183s
map! with capitalize! & logical or
                        638.403k (± 1.1%) i/s -      3.231M in   5.062264s
map! capitalize! & two statements
                        609.576k (± 1.3%) i/s -      3.075M in   5.045232s
                gsub    370.714k (± 1.6%) i/s -      1.886M in   5.088413s
            gsub alt    381.659k (± 1.0%) i/s -      1.944M in   5.093680s

Comparison:
        string split:   674835.2 i/s
                map!:   670842.7 i/s - same-ish: difference falls within error
    each capitalize!:   656590.9 i/s - 1.03x  slower
map! with capitalize! & logical or:   638402.7 i/s - 1.06x  slower
         capitalize!:   632283.9 i/s - 1.07x  slower
map! capitalize! & two statements:   609576.1 i/s - 1.11x  slower
            original:   421622.7 i/s - 1.60x  slower
            gsub alt:   381658.6 i/s - 1.77x  slower
                gsub:   370713.6 i/s - 1.82x  slower

Calculating -------------------------------------
            original     1.680k memsize (     0.000  retained)
                        20.000  objects (     0.000  retained)
                        13.000  strings (     0.000  retained)
        string split   840.000  memsize (     0.000  retained)
                        15.000  objects (     0.000  retained)
                        13.000  strings (     0.000  retained)
    each capitalize!   760.000  memsize (     0.000  retained)
                        14.000  objects (     0.000  retained)
                         7.000  strings (     0.000  retained)
         capitalize!   840.000  memsize (     0.000  retained)
                        15.000  objects (     0.000  retained)
                         7.000  strings (     0.000  retained)
                map!   760.000  memsize (     0.000  retained)
                        14.000  objects (     0.000  retained)
                        13.000  strings (     0.000  retained)
map! with capitalize! & logical or
                       760.000  memsize (     0.000  retained)
                        14.000  objects (     0.000  retained)
                         7.000  strings (     0.000  retained)
map! capitalize! & two statements
                       760.000  memsize (     0.000  retained)
                        14.000  objects (     0.000  retained)
                         7.000  strings (     0.000  retained)
                gsub     1.816k memsize (     0.000  retained)
                        20.000  objects (     0.000  retained)
                        13.000  strings (     0.000  retained)
            gsub alt     1.576k memsize (     0.000  retained)
                        14.000  objects (     0.000  retained)
                         7.000  strings (     0.000  retained)

Comparison:
map! capitalize! & two statements:        760 allocated
    each capitalize!:        760 allocated - same
                map!:        760 allocated - same
map! with capitalize! & logical or:        760 allocated - same
        string split:        840 allocated - 1.11x more
         capitalize!:        840 allocated - 1.11x more
            gsub alt:       1576 allocated - 2.07x more
            original:       1680 allocated - 2.21x more
                gsub:       1816 allocated - 2.39x more