Safe override of Class#new?

ruby-talk
1

class Class
    alias :create :new

    def new(*a,&b)
      obj = allocate
      obj.extend advice
      obj.send(:initialize,*a,&b)
      return obj
    end
  end

Note #advice is a sprcisl module that provides AOP features.

Like to get the opinions of other Ruby experts on this. What kind of
potential trouble am I asking for by using this?

Thanks,
T.

2

Like to get the opinions of other Ruby experts on this. What
kind of potential trouble am I asking for by using this?

(Not that I'm a Ruby expert, but anyway...)

You'll run into a real slowdown of your application. AFAIK,
creating objects is one of the most expensive operations in any
OO language. Even when it's implemented in C, as is done with
Ruby.

Yeah, sure, go ahead, implement it in Ruby and slow it down by
a factor of three!... :}

(Just kidding...)

gegroet,
Erik V. - http://www.erikveen.dds.nl/

···

----------------------------------------------------------------

require "benchmark"

class Class
   alias :create :new

   def new_new(*a, &b)
     obj = allocate
     obj.send(:initialize, *a, &b)
     obj
   end
end

times = 1_000_000

Benchmark.bmbm do |bm|
   bm.report("old_new") do
     times.times do
       Object.new
     end
   end

   bm.report("new_new") do
     times.times do
       Object.new_new
     end
   end
end

----------------------------------------------------------------

<snip/>

               user system total real
old_new 0.680000 0.010000 0.690000 ( 0.687622)
new_new 1.880000 0.010000 1.890000 ( 1.889214)

----------------------------------------------------------------

3

Ouch. Sigh, any way I seem to slice it, AOP in pure Ruby sucks.

T.

···

On Mar 5, 3:39 pm, "Erik Veenstra" <erikv...@gmail.com> wrote:

> Like to get the opinions of other Ruby experts on this. What
> kind of potential trouble am I asking for by using this?

(Not that I'm a Ruby expert, but anyway...)

You'll run into a real slowdown of your application. AFAIK,
creating objects is one of the most expensive operations in any
OO language. Even when it's implemented in C, as is done with
Ruby.

Yeah, sure, go ahead, implement it in Ruby and slow it down by
a factor of three!... :}

(Just kidding...)

gegroet,
Erik V. -http://www.erikveen.dds.nl/

----------------------------------------------------------------

require "benchmark"

class Class
   alias :create :new

   def new_new(*a, &b)
     obj = allocate
     obj.send(:initialize, *a, &b)
     obj
   end
end

times = 1_000_000

Benchmark.bmbm do |bm|
   bm.report("old_new") do
     times.times do
       Object.new
     end
   end

   bm.report("new_new") do
     times.times do
       Object.new_new
     end
   end
end

----------------------------------------------------------------

<snip/>

               user system total real
old_new 0.680000 0.010000 0.690000 ( 0.687622)
new_new 1.880000 0.010000 1.890000 ( 1.889214)

4

Trans schrieb:

Ouch. Sigh, any way I seem to slice it, AOP in pure Ruby sucks.

Welcome to the club :frowning:

Regards,
Pit

5

OTOH, do you really want to AOP-ify all Ruby classes? Maybe you can
apply the advice to a limited subset of classes. The performance hit
might be acceptable in the end.

···

On Mar 6, 1:38 am, "Trans" <transf...@gmail.com> wrote:

Ouch. Sigh, any way I seem to slice it, AOP in pure Rubysucks.

6

Thank you. I think that will indeed be enough.

T.

···

On Mar 6, 6:10 pm, "Paolo Nusco Perrotta" <paolo.nusco.perro...@gmail.com> wrote:

On Mar 6, 1:38 am, "Trans" <transf...@gmail.com> wrote:

> Ouch. Sigh, any way I seem to slice it, AOP in pure Rubysucks.

OTOH, do you really want to AOP-ify all Ruby classes? Maybe you can
apply the advice to a limited subset of classes. The performance hit
might be acceptable in the end.