in reply to Proxying (almost) all methods in a class for mass memoization

This:

      return $outputs->{ $call_key } if defined $outputs->{ $call_key 
+};

      $outputs->{ $call_key } = $self->$orig( @args );

      return $outputs->{ $call_key };

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Would be more concise like this:

      return( $outputs->{$call_key} //= $self->$orig(@args) );

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As it's the last line in the sub, you don't even need the return keyword. (And sub calls are slightly optimized if you leave it out.)

One thing to beware: get_method_list doesn't return a list of all methods — it doesn't include inherited methods. You could use get_all_methods (which retuns Moose::Meta::Method objects instead of a list of method names as strings, so you will need to do $_->name on each).

toby döt ink

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Re^2: Proxying (almost) all methods in a class for mass memoization
by hippo (Archbishop) on Aug 16, 2018 at 08:06 UTC
    And sub calls are slightly optimized if you leave [return] out.

    That's a surprising twist. I would have imagined that such a thing would have been easily optimised away at compilation. I'm going to have to start benchmarking frequently-called, tiny subs to see what sort of difference this makes. Thanks (I think)!

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      > I would have imagined that such a thing would have been easily optimised away at compilation

      And, unsurprisingly, it's been the case since 5.20!

      ($q=q:Sq=~/;[c](.)(.)/;chr(-||-|5+lengthSq)`"S|oS2"`map{chr |+ord
}map{substrSq`S_+|`|}3E|-|`7**2-3:)=~y+S|`+$1,++print+eval$q,q,a,

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        I wonder what it takes to trigger that optimization.

        davido:~/scripts$ perlbrew exec --with perl-5.10.1 perl mytest.pl
Perl version: 5.010001

          Rate retn bare
retn 6849315/s   --  -8%
bare 7462687/s   9%   --

(25000000, 25000000)


davido:~/scripts$ perlbrew exec --with perl-5.28.0 perl mytest.pl
Perl version: 5.028000

           Rate bare retn
bare 10729614/s   --  -3%
retn 11013216/s   3%   --

(25000000, 25000000)

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        I mean I do see a difference, but other optimizations between Perl 5.10 and Perl 5.28 seem to be far more significant (probably the integer optimization).

        Here is the sample code:

        use strict;                      
use warnings;                    
                                 
use Benchmark qw(cmpthese);      
                                 
my $x;                           
my $y;                           
                                 
sub bare { ++$x; $x }            
sub retn { ++$y; return $y }     
                                 
print "Perl version: $]\n\n";    
                                 
cmpthese(25_000_000, {           
    bare => sub {my $t = bare()},
    retn => sub {my $t = retn()},
});                              
                                 
print "\n($x, $y)\n";

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        The reason for the double sub call is to assure that the return value is being obtained, and not discarded due to context. So we do have the double-call overhead, but it's the same overhead for both sides of the test.

        Anyway, where there had been a 9% difference in favor of bare returns in 5.10, there's now a statistically insignificant 3% difference that seems to go either direction.


        Dave

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Re^2: Proxying (almost) all methods in a class for mass memoization
by Anonymous Monk on Aug 16, 2018 at 10:59 UTC
    Appreciate the feedback and the useful insights, tobyink! The bit about return()ing from subs... that's revelatory for sure!
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In Section Cool Uses for Perl