performance improvements for Bundler and Gem::Version#<=>

bench.rb

require 'rubygems'

# diff --git a/lib/rubygems/version.rb b/lib/rubygems/version.rb
# index 50d8204..4962ce1 100644
# --- a/lib/rubygems/version.rb
# +++ b/lib/rubygems/version.rb
# @@ -295,12 +295,16 @@ class Gem::Version
#      rhsize = other.segments.size
#      limit  = (lhsize > rhsize ? lhsize : rhsize) - 1
#  
# +    lhsegments = segments
# +    rhsegments = other.segments
# +
#      0.upto(limit) do |i|
# -      lhs, rhs = segments[i] || 0, other.segments[i] || 0
# +      lhs, rhs = lhsegments[i] || 0, rhsegments[i] || 0
#  
# +      next               if lhs == rhs
#        return  -1         if String  === lhs && Numeric === rhs
#        return   1         if Numeric === lhs && String  === rhs
# -      return lhs <=> rhs if lhs != rhs
# +      return lhs <=> rhs
#      end
#  
#      return 0
class Gem::FastVersion < Gem::Version
  def <=> other
    return   1 unless other # HACK: comparable with nil? why?
    return nil unless self.class === other

    lhsize = segments.size
    rhsize = other.segments.size
    limit  = (lhsize > rhsize ? lhsize : rhsize) - 1

    lhsegments = segments
    rhsegments = other.segments

    0.upto(limit) do |i|
      lhs, rhs = lhsegments[i] || 0, rhsegments[i] || 0

      next               if lhs == rhs
      return  -1         if String  === lhs && Numeric === rhs
      return   1         if Numeric === lhs && String  === rhs
      return lhs <=> rhs
    end

    return 0
  end
end

class Gem::FasterVersion < Gem::FastVersion
  def <=> other
    return   0 if version == other.version
    super
  end
end

require 'version_sorter' # http://github.com/defunkt/version_sorter
class Gem::CExtVersion < Gem::Version
  def <=> other
    return   1 unless other # HACK: comparable with nil? why?
    return nil unless self.class === other
    return   0 if version == other.version

    # XXX: this does not follow rubygems' prelease versioning rules
    VersionSorter.sort([version, other.version]).first == version ?
      -1 :
       1
  end
end

require 'benchmark'
Benchmark.bmbm do |b|
  [ Gem::Version, Gem::FastVersion, Gem::FasterVersion, Gem::CExtVersion ].each do |klass|
    b.report klass.to_s do
      a = klass.new('3.0.0.0.0')
      b = klass.new('3.0.0.0.0')
      c = klass.new('3.0.0.0.3')

      250_000.times do
        a <=> b
        b <=> c
      end
    end
  end
end

__END__


Rehearsal ------------------------------------------------------
Gem::Version        10.630000   0.020000  10.650000 ( 10.731254)
Gem::FastVersion     7.270000   0.010000   7.280000 (  7.359935)
Gem::FasterVersion   4.370000   0.010000   4.380000 (  4.408528)
Gem::CExtVersion     3.520000   0.010000   3.530000 (  3.540201)
-------------------------------------------- total: 25.840000sec

                         user     system      total        real
Gem::Version        11.430000   0.020000  11.450000 ( 11.513403)
Gem::FastVersion     7.230000   0.010000   7.240000 (  7.313092)
Gem::FasterVersion   4.450000   0.010000   4.460000 (  4.478300)
Gem::CExtVersion     3.500000   0.010000   3.510000 (  3.539400)

bundler_rubygems_profile.png