From: Rick DeNatale <rick.denatale@...>
Date: 2006-10-27T01:07:33+09:00
Subject: Re: ruby-prof vs. Object#clone

On 10/26/06, Victor 'Zverok' Shepelev <vshepelev@imho.com.ua> wrote:
> Jan Svitok (jan.svitok@gmail.com)
> 26/10/2006 13:56:01
>
> > On 10/26/06, Victor 'Zverok' Shepelev <vshepelev@imho.com.ua> wrote:
> > > For some reasons I extensively use this technique:
> > >
> > > obj = MyClass.new(...)
> > > obj.instance_eval{
> > >   def my_cool_method
> > >   end
> > > }
> > >
> > > #create 1000 clones of the obj, call #my_cool_method
> > > (1..1000).collect{
> > >   clon = obj.clone
> > >   clon.my_cool_method
> > > }
> > >
> > > The problem is ruby-prof shows each clone's #my_cool_method as separate
> > > one in the report, so I see 1000 lines with 1 calls of #my_cool_method
> > > instead of 1 line with 1000 calls. Is it bug or by design? May this
> > > problem be result of the fact I use latest Ruby 1.9 version?
> >
> > This is what I've found in the sources:
> > My_cool_method is a singleton instance method (not an ordinary
> > instance method). singleton methods are cloned by creating proxy
> > method, so they are not identical.
> >
>
> OK, I've got it.
> Thanks.
>
> > IMHO the most simple way is to define normal instance methods via
> >
> > obj.class.module_eval, i.e. MyClass.module_eval.
>
> Not for me, unfortunately :(
> One of reasons, why I use those strange techniques, is to have different sets of methods in different sets of objects of same class.
>
> More specially, all those objects are HTML DOM nodes, and I want to have #cell(col, row) method for <table> node, #click method for <button> node and even more special cases, like have some special methods for <table class=grid>. My approach is on-the-fly per-CSS-selector extending of certain nodes, and it works well, except for profiling :(

Will something like this meet your needs?

rick@frodo:/public/rubyscripts$ cat mycool.rb
class MyClass
end

module MyCoolModule
  def my_cool_method
  end
end
obj = MyClass.new
obj.extend MyCoolModule

#create 1000 clones of the obj, call #my_cool_method
(1..1000).collect{
 clon = obj.clone
 clon.my_cool_method
}

rick@frodo:/public/rubyscripts$ ruby -r profile mycool.rb
  %   cumulative   self              self     total
 time   seconds   seconds    calls  ms/call  ms/call  name
 53.04     0.61      0.61        1   610.00  1140.00  Range#each
 28.70     0.94      0.33     1000     0.33     0.40  Kernel.clone
 11.30     1.07      0.13     1000     0.13     0.13
MyCoolModule.my_cool_method
  6.09     1.14      0.07     1000     0.07     0.07  Kernel.initialize_copy
  0.00     1.14      0.00        1     0.00     0.00  Module#extended
  0.00     1.14      0.00        1     0.00     0.00  Kernel.extend
  0.00     1.14      0.00        1     0.00     0.00  Class#new
  0.00     1.14      0.00        1     0.00     0.00  Class#inherited
  0.00     1.14      0.00        1     0.00  1140.00  Enumerable.collect
  0.00     1.14      0.00        1     0.00     0.00  Object#initialize
  0.00     1.14      0.00        1     0.00     0.00  Module#extend_object
  0.00     1.14      0.00        1     0.00     0.00  Module#method_added
  0.00     1.15      0.00        1     0.00  1150.00  #toplevel
rick@frodo:/public/rubyscripts$

-- 
Rick DeNatale

My blog on Ruby
http://talklikeaduck.denhaven2.com/