benchmark-xml-builders.rb

#! /usr/bin/env ruby

require "bundler/inline"

gemfile do
  source "https://rubygems.org"
  gem "builder"
  gem "nokogiri"
  gem "benchmark-ips"
end

require "builder"
require "nokogiri"
require "benchmark/ips"

N = 100

# using Builder::XmlMarkup, build an XML document representing attributes of a person
def builder_person
  xml = Builder::XmlMarkup.new
  xml.people do |p|
    N.times do
      xml.person do |p|
        p.name "John Doe"
        p.age 42
        p.address do |a|
          a.street "123 Main Street"
          a.city "Anytown"
        end
      end
    end
  end
end

# using Nokogiri::XML::Builder, build an XML document representing attributes of a person
def nokogiri_person
  Nokogiri::XML::Builder.new do |xml|
    xml.people do
      N.times do
        xml.person do |p|
          p.name "John Doe"
          p.age 42
          p.address do |a|
            a.street "123 Main Street"
            a.city "Anytown"
          end
        end
      end
    end
  end.to_xml
end

# use Nokogiri's bare API to build an XML document representing attributes of a person
def nokogiri_raw_person
  doc = Nokogiri::XML::Document.new
  doc.root = doc.create_element("people")
  N.times do
    doc.root.add_child(doc.create_element("person")).tap do |p|
      p.add_child(doc.create_element("name", "John Doe"))
      p.add_child(doc.create_element("age", 42))
      p.add_child(doc.create_element("address")).tap do |a|
        a.add_child(doc.create_element("street", "123 Main Street"))
        a.add_child(doc.create_element("city", "Anytown"))
      end
    end
  end
  doc.to_xml
end

puts RUBY_DESCRIPTION
# pp builder_person
# pp nokogiri_person
# pp nokogiri_raw_person

Benchmark.ips do |x|
  x.report("Builder") { builder_person }
  x.report("Nokogiri::XML::Builder") { nokogiri_person }
  x.report("Nokogiri::XML::Document") { nokogiri_raw_person }
  x.compare!
end

benchmark.txt

$ ruby ./issues/benchmark-xml-builders.rb 
ruby 3.2.2 (2023-03-30 revision e51014f9c0) [x86_64-linux]
Warming up --------------------------------------
             Builder    54.000  i/100ms
Nokogiri::XML::Builder
                        47.000  i/100ms
Nokogiri::XML::Document
                        47.000  i/100ms
Calculating -------------------------------------
             Builder    539.632  (± 7.6%) i/s -      2.700k in   5.034709s
Nokogiri::XML::Builder
                        475.543  (± 8.6%) i/s -      2.397k in   5.086260s
Nokogiri::XML::Document
                        722.282  (± 5.7%) i/s -      3.619k in   5.028424s

Comparison:
Nokogiri::XML::Document:      722.3 i/s
             Builder:      539.6 i/s - 1.34x  slower
Nokogiri::XML::Builder:      475.5 i/s - 1.52x  slower