[Dbix-class] Re: Can't modify prefetch

[Peter Rabbitson]

Tim Bunce wrote:
> On Sat, Nov 27, 2010 at 02:13:48PM +0100, Peter Rabbitson wrote:
>> Ryan Tate wrote:
>>> Nevermind, I stupidly forgot to assign the modified resultset :-) I'll
>>> pull the RT bug too.....
>> Next version will have this so people won't be confused as easily:
>> http://git.shadowcat.co.uk/gitweb/gitweb.cgi?p=dbsrgits/DBIx-Class.git;a=commitdiff;h=0e7a447e570daf41c11b403fd81046756894cc27
> 
> Micro-optimization: the wantarray op is faster than using a temp variable.
> 

Indeed, thanks, will fix :)

      Rate  var  ops
var 121/s   -- -19%
ops 148/s  23%   --



use strictures 1;
use Benchmark qw/cmpthese/;

my $ops = sub {
   if (wantarray) {
     1
   }
   elsif (defined wantarray) {
     2
   }
   else {
     3
   }
};

my $var = sub {
   my $want = wantarray;

   if ($want) {
     1
   }
   elsif (defined $want) {
     2
   }
   else {
     3
   }
};

cmpthese (-1 => {
   ops => sub {
     for (1..10000) {
       $ops->();
       1;
     }
   },
   var => sub {
     for (1..10000) {
       $var->();
       1;
     }
   },
});