Thanks for your replies.
The best route for me, then, seems to be to go ahead and use
MX::Declare --- it really is handy! --- profile, and make the most
heavily used stuff regular subs (instead of methods()).
--abhijit
On Mon, Nov 16, 2009 at 7:42 AM, Jesse Luehrs <d...@tozt.net> wrote:
> On Mon, Nov 16, 2009 at 09:20:37AM -0600, Nick Perez wrote:
>> On Sun, 15 Nov 2009 21:02:25 -0800
>> abhijit mahabal <amaha...@gmail.com> wrote:
>>
>> > Hi Moose folks,
>> > I recently began converting my PhD code from Class::Std to
>> > MooseX::Declare. (I started to write that code over 5 years ago, hence
>> > Class::Std).
>> >
>> > I have run into a slowness roadblock, however, and I feel I must be
>> > doing something wrong. I was under the impression that I would only be
>> > paying compile time costs, but the runtime costs I have run into are
>> > prohibitive. I have included a benchmark script below.
>> >
>> > I am using perl5.10.1 on Ubuntu, MX::Declare 0.32,
>> > MooseX::Method::Signatures 0.29.
>> >
>> > ============
>> > Rate method_without_type method_with_type
>> > regular_sub
>> > method_without_type 4374/s --
>> > -7% -99% method_with_type 4721/s
>> > 8% -- -99% regular_sub
>> > 389610/s 8808% 8152% --
>> > ============= use MooseX::Declare;
>> >
>> > class Foo {
>> > has x => (
>> > is => 'rw',
>> > isa => 'Str',
>> > );
>> >
>> > # I use the three vars below to ensure that the subs
>> > # are not constant-folded away.
>> > our $meth_counter = 0;
>> > our $meth_typed_counter = 0;
>> > our $regular_sub_counter = 0;
>> >
>> > method method_with_type( Int $x ) {
>> > $meth_typed_counter++;
>> > $self->x . $x
>> > };
>> >
>> > method method_without_type($x) {
>> > $meth_counter++;
>> > $self->x . $x
>> > };
>> >
>> > sub regular_sub {
>> > my ( $self, $x ) = @_;
>> > $regular_sub_counter++;
>> > $self->x . $x;
>> > }
>> >
>> > };
>> >
>> > package main;
>> > use Benchmark qw(:all);
>> >
>> > my $foo = Foo->new( { x => "3" } );
>> > cmpthese(
>> > 300000,
>> > {
>> > regular_sub => sub { $foo->regular_sub(5) },
>> > method_without_type => sub { $foo->method_without_type(5) },
>> > method_with_type => sub { $foo->method_with_type(5) }
>> > }
>> > );
>> > =============
>> >
>> >
>> > Is this expected? If not, what am I doing wrong? And why does adding a
>> > type *speed* things up (by 8% in the example above)? That's
>> > counterintuitive, to me.
>> >
>> > Thanks much,
>> > --abhijit
>> >
>>
>>
>> You have to understand what kind of magic is happening behind the
>> scenes to realize that methods can be heavy. First, the type constraint
>> system alone will slow things down. Also, the provided arguments to a
>> method are munged to allow for things like named parameters. And then
>> the sub is basically rewritten (MXD is a glorified source filter but
>> using perl to parse Perl) to account for all of that. If you are
>> interested in the gory details, take a look inside
>> MooseX::Method::Signatures::Meta::Method.
>>
>> So that answers to the general slowness, as for why adding a type
>> speeds things up, that is a question for Florian. You are welcome to
>> join the #devel-declare channel on irc.perl.org, most of the MXD people
>> hang out there.
>
> Also, to clarify things a bit, with plain Moose you should have minimal
> runtime overhead, which is probably what you had been hearing.
> MooseX::Declare does quite a bit beyond Moose, and some of these things
> affect runtime speed, as Nick said.
>
> -doy
>
--
-- Abhijit
