# Module#name very slow for anonymous modules

**URL:** <https://www.ruby-forum.com/t/module-name-very-slow-for-anonymous-modules/149814>\
**Category:** Rails\
**Created:** [September 30, 2008, 5:58am UTC](https://www.ruby-forum.com/t/module-name-very-slow-for-anonymous-modules/149814 "2008-09-30T05:58:43Z")\
**Posts on this page:** 3\
**Page:** 1

<div class="post-metadata">

**Author:** ![curi](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/c/e68b1a/32.png) [@curi](https://www.ruby-forum.com/u/curi)\
**Post date:** [September 30, 2008, 5:58am UTC](https://www.ruby-forum.com/t/module-name-very-slow-for-anonymous-modules/149814/1 "2008-09-30T05:58:43Z")

</div>

Notice it gets much worse with rails loaded. Anyone got a fix, or know  
why this is happening?

cg5[20:55] development \> ruby -v  
ruby 1.8.6 (2008-03-03 patchlevel 114) [universal-darwin9.0]  
cg5[20:51] development \> irb  
irb(main):001:0\> require ‘benchmark’  
=\> true  
irb(main):002:0\> n = 5000  
=\> 5000  
irb(main):003:0\> m1 = Module.new  
=\> #Module:0x5d6c54  
irb(main):004:0\> module M2; end  
=\> nil  
irb(main):005:0\> Benchmark.bm do |x|  
irb(main):006:1\* x.report { n.times do m1.name end }  
irb(main):007:1\> x.report { n.times do M2.name end }  
irb(main):008:1\> end  
user system total real  
1.710000 0.050000 1.760000 ( 2.807539)  
0.010000 0.000000 0.010000 ( 0.005157)  
=\> true  
irb(main):009:0\> ^Dcg5[20:51] development \> script/console  
Loading development environment (Rails 2.0.2)

> > require ‘benchmark’  
> > =\> []
> 
> > n = 5000  
> > =\> 5000
> 
> > m1 = Module.new  
> > =\> #Module:0x205c308
> 
> > module M2; end  
> > =\> nil
> 
> > Benchmark.bm do |x|  
> > ?\> x.report { n.times do m1.name end }
> 
> > x.report { n.times do M2.name end }  
> > end  
> > user system total real  
> > 14.120000 0.630000 14.750000 ( 28.017196)  
> > 0.000000 0.000000 0.000000 ( 0.010137)  
> > =\> true
> 
> >

---

<div class="post-metadata">

**Author:** ![curi](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/c/e68b1a/32.png) [@curi](https://www.ruby-forum.com/u/curi)\
**Post date:** [September 30, 2008, 9:19pm UTC](https://www.ruby-forum.com/t/module-name-very-slow-for-anonymous-modules/149814/2 "2008-09-30T21:19:18Z")

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Looks like the code changed in edge rails, but as a temporary patch do  
this one line change in environment.rb which avoids calling Module#name  
if there is no name:

module ActionView  
module Helpers  
module PrototypeHelper  
class JavaScriptGenerator  
def include\_helpers\_from\_context  
@context.extended\_by.each do |mod|  
extend mod unless defined?(mod) == ‘constant’ && mod.name =~  
/^ActionView::Helpers/  
end  
extend GeneratorMethods  
end  
end  
end  
end  
end

---

<div class="post-metadata">

**Author:** ![curi](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/c/e68b1a/32.png) [@curi](https://www.ruby-forum.com/u/curi)\
**Post date:** [September 30, 2008, 11:26pm UTC](https://www.ruby-forum.com/t/module-name-very-slow-for-anonymous-modules/149814/3 "2008-09-30T23:26:43Z")

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On Sep 30, 4:58 am, Elliot T. [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid)  
wrote:

> Notice it gets much worse with rails loaded. Anyone got a fix, or know  
> why this is happening?

I don’t think it is Rails’ fault (at least not directly).  
I ran the test you ran and got:

```
  user system total real

```

0.710000 0.010000 0.720000 ( 0.715909)  
0.010000 0.000000 0.010000 ( 0.013030)

Then I ran ‘Aaaa’.upto(‘Azzz’) { |x| Object.const\_set(x, ‘1’), ie I  
generated 20000 or so extra constants and reran the benchmarks and got

22.300000 0.250000 22.550000 ( 23.584470)  
0.000000 0.000000 0.000000 ( 0.005260)

Adding the same number of constants again doubles those numbers - it  
would appear that there is something in ruby that makes Module#name  
linear in the number of constants set in the case where the name is  
unset  
So I don’t think Rails is doing anything that makes this worse, other  
than defining a whole bunch of constants

Fred