Re: Moose speed and schedule

On Nov 11, 2006, at 11:11 PM, Stevan Little wrote:

> Jonathan,
>
>> Unfortunately, the current object construction slowness will make  
>> this a non-starter. e.g. On my powerbook it takes 25ms of CPU time  
>> for Moose to construct a dead-simple object with a single accessor  
>> and no inheritance.
>
> Yes, this is a well known issue, and one I am currently working on  
> solving it.
>
> A question though, is this benchmark including Class::MOP/Moose  
> compile time? Because that is something we cannot do too much about  
> at the moment, which means Moose is really only usable in  
> persistent environments like mod_perl/FastCGI/etc.

No, this does not include compile time - I do work in persistent  
environments so I'd be willing to live with some startup costs.

Here's the benchmark source:

    #!/usr/bin/perl
    use Benchmark;
    use strict;
    use warnings;

    { package MoosePage;
      use Moose;

      has 'title' => (is => 'rw');
    }

    { package ClassAccessorPage;
      use strict;
      use warnings;
      use base qw(Class::Accessor);

      __PACKAGE__->mk_accessors(qw(title));
    }

    printf "Using Moose version %s, Class::MOP version %s,  
Class::Accessor version %s\n", $Moose::VERSION, $Class::MOP::VERSION,  
$Class::Accessor::VERSION;

    timethese(1000, {
        'MoosePage' => sub { my $page = new MoosePage(title =>  
'article') },
        'ClassAccessorPage' => sub { my $page = new ClassAccessorPage 
({title => 'article'}) },
              });

Results on my 1.5 GHz PowerPC G4:

    swartz> ./bench.pl
    Using Moose version 0.15, Class::MOP version 0.36,  
Class::Accessor version 0.27
    Benchmark: timing 1000 iterations of ClassAccessorPage, MoosePage...
    ClassAccessorPage:  0 wallclock secs ( 0.02 usr +  0.00 sys =   
0.02 CPU) @ 50000.00/s (n=1000)
                (warning: too few iterations for a reliable count)
     MoosePage: 22 wallclock secs (18.41 usr +  0.33 sys = 18.74 CPU)  
@ 53.36/s (n=1000)

It's pretty simple - even the accessor declarations are superfluous  
since I'm just calling constructors, though oddly if I take out the  
'has' declaration Moose gets a little slower.

>> http://code2.0beta.co.uk/moose/svn/Moose/trunk/lib/Moose/Cookbook/ 
>> FAQ.pod mentions that immutable classes may eliminate, or at least  
>> vastly improve, object construction performance, and implies this  
>> will hopefully be done by the end of the year. Does this schedule  
>> still sound reasonable?
>
> There is currently an experimental branch of the immutable Moose
>
> http://code2.0beta.co.uk/moose/svn/Moose/branches/Moose-immutable/
>
> it requires this branch from Class-MOP as well
>
> http://code2.0beta.co.uk/moose/svn/Class-MOP/branches/Class-MOP- 
> tranformations/
>
> It is not yet finished, but the plan is to get it completely  
> working by the end of this month. Production worthiness will take a  
> little longer of course, probably close to that "end of the year"  
> timeline.
>
> Early benchmarks show an average performance boost of 400-500%,  
> with a upper ceiling of 1200% for really simple constructors and a  
> bottom of about 175% for very complex constructors. A lot of this  
> is dependent upon the complexity of your attributes, and I do my  
> best to make sure you only pay for what you actually use.
>
> This branch also includes a speed up version of the type constraint  
> system as well, which shows a performance boost of around 400% from  
> previous versions. This also contributes to the speedup in object  
> construction as well.
>

Ok! That's good to know. I can't afford to be that much on the  
bleeding edge for this project, but I'll happily try out the next  
CPAN release when it's available.

>> In the meantime, does anyone have a recommendation for an  
>> alternate class framework I can use that will make the eventual  
>> jump to Moose as painless as possible?
>
> Well, it all depends on what Moose features you use.

We've just started out so it's hard to know which Moose features we'd  
be using. The accessor and type declarations and default  
constructors, of course - these are available elsewhere on CPAN but I  
like Moose's syntax far better than others. Before and after methods  
are nice too. Hopefully any class introspection we end up doing will  
be "pay for what you use" as you suggest.

Have you thought about some global flag, or at least a per-class  
flag, to enable/disable type constraint checking? It would make sense  
to enable type checking for development servers and disable for  
production servers.

> One alternative, which I use myself, is to downgrade to Moose 0.11  
> (and Class::MOP 0.30 or so). It is still a little slow, but much  
> more manageable, especially if you are still in the development  
> phase where speed really shouldn't be that important.

Cool - I'll try these out in the benchmark.

Jon