ERB_vs_Builder.rb

require 'rubygems' 
require "builder"
require "benchmark"
require 'nokogiri' 
require 'erb' 
require 'erubis'

ITERATIONS = 1_000

ERB_TEMPLATE = <<-EOL
  <jobs>
    <%
      ITERATIONS.times do
    %>
    <job>
      <zid><%= 123 %></zid>
      <name><%= "job" + rand(100).to_s %></name>
      <state><%= "Started" %></state>
      <resource_id><%= 1 %></resource_id>
      <steps>
        <%
          20.times do
        %>
          <zid><%= 123 %></zid>
          <name><%= "Milestone" + rand(1000).to_s %></name>
          <completed_at><%= Time.now.to_s %></completed_at>
        <%
          end
        %>
      </steps>
    </job>
    <%
      end
    %>
  <jobs>
EOL

def do_nokogiri
  xml = Nokogiri::XML::Builder.new 
  build_xml(xml)
end

def do_builder
  xml = Builder::XmlMarkup.new
  build_xml(xml)
end

def do_erubis
  template = Erubis::Eruby.new(ERB_TEMPLATE)
  template.result(binding())
end

def do_erb
  template = ERB.new(ERB_TEMPLATE)  
  template.result(binding)
end

def build_xml(xml)
  xml.jobs do
    ITERATIONS.times do
      xml.job do
        xml.zid "123"
        xml.name "My REALLY BIG Job"
        xml.state "Started"
        xml.resource_id "1"
        xml.steps do
          20.times do
            xml.step do
              xml.zid "123"
              xml.name "Milestone"
              xml.completed_at Time.now.to_s
            end
          end
        end
      end
    end
  end  
end

Benchmark.bmbm do |x|
  x.report("Erb") { do_erb }
  x.report("Erubis") { do_erubis }
  x.report("Nokogiri") { do_nokogiri }
  x.report("Builder") { do_builder }
end


#                user     system      total        real
# Erb        0.160000   0.000000   0.160000 (  0.168597)
# Erubis     0.180000   0.010000   0.190000 (  0.182917)
# Nokogiri   3.510000   0.030000   3.540000 (  3.548115)
# Builder    3.310000   0.050000   3.360000 (  3.362523)