Improve performance of checking domains

[Bishop]

I need to analyse thousands of domains and it takes much time.

Some experiments:

    def domain_is_in?(domain_list)
      domain_list.select { |domain|
        address.domain =~ (/\A(.*\.)*#{domain}\z/i)
      }.any?
    end

    def domain_is_in_2?(domain_list)
      domain_list.any? { |domain|
        address.domain =~ /\A(.*\.)*#{domain}\z/i
      }
    end

    def domain_is_in_3?(domain_list)
      address_domain = address.domain.downcase
      domain_list.any? { |domain|
        address_domain =~ /\A(?:.+\.)*?#{domain}\z/
      }
    end

    def domain_is_in_4?(domain_list)
      address_domain = address.domain.downcase
      domain_list.any? { |domain|
        address_domain.end_with?(domain) && address_domain =~ /\A(?:.+\.)*?#{domain}\z/
      }
    end

Code:

a = ValidEmail2::Address.new 'alex...@gmail.com'

n = 100
Benchmark.bm do |x|
  x.report { n.times do ; a.disposable?; end }
  x.report { n.times do ; a.disposable2?; end }
  x.report { n.times do ; a.disposable3?; end }
  x.report { n.times do ; a.disposable4?; end }
end

Results:

       user     system      total        real
   3.520000   0.090000   3.610000 (  3.628667)
   3.450000   0.050000   3.500000 (  3.499219)
   2.460000   0.040000   2.500000 (  2.511812)
   0.020000   0.000000   0.020000 (  0.023849)

It looks like 100x improvement.

[micke]

Thanks!