parser_speedtest.rb

require "nokogiri"
require "hpricot"
require "open-uri"

#on my macbook
#$ ruby speedtest.rb 
#uri took: 4.539837
#hpricot took: 3.490182
#nokogiri took: 6.273096

#on EC2 small:
#uri took: 11.428387987
#hpricot took: 8.071451074000001
#nokogiri took: 12.722893389


puts "getting data"
html_string = open("http://www.reddit.com/").readlines.join("\n")
puts "done"
def extract_links_noko_css(html)
      new_links = Array.new
      Nokogiri::HTML(html).css("a").each do |link|
        link_to = link.attributes["href"].content rescue nil
        new_links << link_to
        end
      new_links.uniq
end

def extract_links_noko_css_nocontent(html)
      new_links = Array.new
      Nokogiri::HTML(html).css("a").each do |link|
        link_to = link.attributes["href"] rescue nil
        new_links << link_to
        end
      new_links.uniq
end

def extract_links_noko_xpath(html)
      new_links = Array.new
      Nokogiri::HTML(html).search("//a[@href]").each do |link|
        link_to = link["href"]
        new_links << link_to
        end
      new_links.uniq
end

def extract_links_noko_xpath_nohref(html)
      new_links = Array.new
      Nokogiri::HTML(html).search("//a").each do |link|
        link_to = link["href"] rescue nil
        new_links << link_to
        end
      new_links.uniq
end
    
    
def extract_links_hpricot(html)
    new_links = Array.new
      Hpricot(html).search("//a[@href]").each do |link|
        link_to = link["href"]        
        new_links << link_to
        end
      new_links.uniq
end

def extract_links_hpricot_css(html)
    new_links = Array.new
      Hpricot(html).search("a").each do |link|
        link_to = link.attributes["href"].content rescue nil
        new_links << link_to
        end
      new_links.uniq
end

def extract_links_hpricot_nohref(html)
    new_links = Array.new
      Hpricot(html).search("//a").each do |link|
        link_to = link["href"]
        new_links << link_to
        end
      new_links.uniq
end
    
  


start = Time.now
  
250.times do
	bla = extract_links_hpricot(html_string)
end
took = Time.now - start
puts "hpricot (xpath) took: #{took}"

start = Time.now

250.times do
	bla = extract_links_hpricot_nohref(html_string)
end
took = Time.now - start
puts "hpricot (xpath, no href) took: #{took}"

start = Time.now

250.times do
	bla = extract_links_hpricot_css(html_string)
end
took = Time.now - start
puts "hpricot (css) took: #{took}"





start = Time.now
  
250.times do
	bla = extract_links_noko_xpath(html_string)
end
took = Time.now - start
puts "nokogiri (xpath) took: #{took}"

start = Time.now

250.times do
	bla = extract_links_noko_css_nocontent(html_string)
end
took = Time.now - start
puts "nokogiri (css_nocontent) took: #{took}"



start = Time.now

250.times do
	bla = extract_links_noko_css(html_string)
end
took = Time.now - start
puts "nokogiri (css) took: #{took}"

start = Time.now

250.times do
	bla = extract_links_noko_xpath_nohref(html_string)
end
took = Time.now - start
puts "nokogiri (xpath no href) took: #{took}"

results

hpricot (xpath) took: 3.599083
hpricot (xpath, no href) took: 3.283622
hpricot (css) took: 4.996853
nokogiri (xpath) took: 4.169071
nokogiri (css_nocontent) took: 4.372877
nokogiri (css) took: 4.494918
nokogiri (xpath no href) took: 3.861592