Ruby: Intelligent hash benchmarks

hash_bench.rb

require 'extlib/mash'
require 'active_support/hash_with_indifferent_access'

GC.disable

h1 = {'a' => "toto", 45 => "yeah", :a_symbol => "a string"}

h2 = HashWithIndifferentAccess.new(h1)

h3 = Hash.new {|hash,key| hash[key.to_s] if Symbol === key }
h3['a_symbol'] = "another string"

h4 = Mash.new
h4['a_symbol'] = "yet another string"


def bench(label, count = 1_000_000)
  started_at = Time.now.to_f
  count.times do
    raise unless yield
  end
  
  elapsed = (Time.now.to_f - started_at) * 1000
  puts "#{label.rjust(30, ' ')} : #{'%.2f' % elapsed} ms"
end


bench("standard by string") do
  h1['a'] == "toto"
end

bench("standard by symbol") do
  h1[:a_symbol] == "a string"
end

puts ""

bench("ar by string") do
  h2['a_symbol'] == "a string"
end

bench("ar by symbol") do
  h2[:a_symbol] == "a string"
end

puts ""

bench("hash with block by string") do
  h3['a_symbol'] == "another string"
end

bench("hash with block by symbol") do
  h3[:a_symbol] == "another string"
end

puts ""

bench("mash by string") do
  h4['a_symbol'] == "yet another string"
end

bench("mash by symbol") do
  h4[:a_symbol] == "yet another string"
end

results

#        standard by string : 323.49 ms
#        standard by symbol : 212.77 ms
# 
#              ar by string : 349.31 ms
#              ar by symbol : 922.98 ms
# 
# hash with block by string : 345.58 ms
# hash with block by symbol : 686.17 ms
# 
#            mash by string : 472.66 ms
#            mash by symbol : 1209.67 ms