simple_is_fast.rb

require 'benchmark'
require 'active_support/core_ext/hash/keys'
require 'active_support/core_ext/hash/indifferent_access'
require 'active_support/core_ext/hash/reverse_merge'
require 'active_support/core_ext/object/try'

n = 1_000_000

options = {:k => :v}

url_options = {:host => 'http://dojo4.com'}


[ {:k => :v}, nil ].each do |options|

  Benchmark.bm do |bm|
  ##
  #
    bm.report "options=#{ options.inspect } - old clever" do
      n.times do

        (options || {}).reverse_merge(url_options).symbolize_keys

      end
    end

  ##
  #
    bm.report "options=#{ options.inspect } - new clever" do
      n.times do

        (options || {}).symbolize_keys.reverse_merge!(url_options)

      end
    end

  ##
  #
    bm.report "options=#{ options.inspect } - simple+correct" do
      n.times do

        dst = {}

        options.keys.each do |k|
          k = k.to_sym
          dst[k] = options[k] unless dst.has_key?(k)
        end if options

        url_options.keys.each do |k|
          k = k.to_sym
          dst[k] = url_options[k] unless dst.has_key?(k)
        end if url_options

        dst

      end
    end

   ##
   #
    bm.report "options=#{ options.inspect } - clever+correct" do
      n.times do
        Hash[ (url_options.to_a + options.to_a).each{|kv| kv[0] = kv[0].to_sym} ]
      end
    end
  end

end


__END__

       user     system      total        real
options=nil - old clever  3.310000   0.040000   3.350000 (  3.351594)
options=nil - new clever  1.650000   0.010000   1.660000 (  1.669478)
options=nil - simple+correct  1.380000   0.020000   1.400000 (  1.406858)
options=nil - clever+correct  1.950000   0.010000   1.960000 (  1.952443)