From: Victor Shepelev <vshepelev@...>
Date: 2006-05-26T00:37:48+09:00
Subject: Re: How use Profiling, a Quick Guide.

From: Robert Klemme [mailto:shortcutter@googlemail.com]
Sent: Thursday, May 25, 2006 6:33 PM
> 2006/5/25, Pedro C�rte-Real <pedrocr@gmail.com>:
> > On 5/24/06, Victor Shepelev <vshepelev@imho.com.ua> wrote:
> > > Here can help my Module#add_tracer, described here
> > > http://blade.nagaokaut.ac.jp/cgi-bin/scat.rb/ruby/ruby-talk/192291
> >
> > That's a nice idea. I made a small modification to count the totals of
> > each of the calling methods instead of printing each time:
> >
> > $traces = Hash.new(0)
> >
> > class Module
> >   def add_tracer(meth)
> >     m_alias = case meth
> >       when :[] : "old_idx"
> >       when :+ : "old_plus"
> >       when :- : "old_minus"
> >       #and so on
> >       else ; "old_#{meth}"
> >     end
> >     module_eval %Q{
> >       alias :#{m_alias} :#{meth}
> >       def #{meth}(*arg, &block)
> >         str = caller[0]+"-"+self.class.name+"-##{meth}"
> >         $traces[str] += 1
> >         #{m_alias}(*arg, &block)
> >       end
> >     }
> >   end
> > end
> >
> > Array.add_tracer(:each)
> >
> > ....
> > Your code here
> > ....
> >
> > $traces.each {|name, value| puts "#{name} - #{value} calls"}
> >
> > You can also sort it by the value in the hash to get an ordered list.
> > This will do for a hack but writing a tracing gem would be great.
> 
> 
> Note that a similar thing can be achieved with set_trace_func

Drawbacks of set_trace_func was discussed in the original topic here:
http://blade.nagaokaut.ac.jp/cgi-bin/scat.rb/ruby/ruby-talk/192294

Victor.