Benchmark tips

[TheDamian]

in reply to Re: Re: Re: Making a match
in thread Making a match

(Sigh. I just can help myself, can I? Always with the advice... ;-)

Two suggestions for using Benchmark:

1. If you're using long names for each test, pad the names to the same length with extra spaces on the left. Then your results are much easier to read and compare:

               Hash Exists Hit:  4 wallclock secs @ 1204819.28/s (n=10000
   +00)
              Hash Defined Hit:  3 wallclock secs @ 2173913.04/s (n=10000
   +00)
              Hash Exists Miss:  1 wallclock secs @ 1515151.52/s (n=10000
   +00)
             Hash Defined Miss:  3 wallclock secs @ 1492537.31/s (n=10000
   +00)
      Hash Assigned Miss Truth:  6 wallclock secs @ 1515151.52/s (n=10000
   +00)
    Hash Assigned Hit Equality:  4 wallclock secs @ 1149425.29/s (n=10000
   +00)
       Hash Assigned Hit Truth:  5 wallclock secs @ 970873.79/s (n=100000
   +0)
   Hash Assigned Miss Equality:  6 wallclock secs @ 877192.98/s (n=100000
   +0)
   

2. Use cmpthese instead of timethese. That adds a handy comparison matrix at the end of your test results (though this suggestion works much better with shorter names):

             Rate  HDH HAHE HAME  HEH HAMT  HDM HAHT  HEM
   HDH  1111111/s   --  -0%  -4% -21% -24% -28% -30% -39%
   HAHE 1111111/s   0%   --  -4% -21% -24% -28% -30% -39%
   HAME 1162791/s   5%   5%   -- -17% -21% -24% -27% -36%
   HEH  1408451/s  27%  27%  21%   --  -4%  -8% -11% -23%
   HAMT 1470588/s  32%  32%  26%   4%   --  -4%  -7% -19%
   HDM  1538462/s  38%  38%  32%   9%   5%   --  -3% -15%
   HAHT 1587302/s  43%  43%  37%  13%   8%   3%   -- -13%
   HEM  1818182/s  64%  64%  56%  29%  24%  18%  15%   --
   

[TheDamian]

WRT suggestion 1: just thought I should mention that I was, of course, far too Lazy to actually align them myself:

use List::Util 'max';
sub align {
    my ($hash) = @_;
    my $len = max map length, keys %$hash;
    $hash->{sprintf "%${len}s", $_} = delete $hash->{$_} 
        for keys %$hash;
    return $hash;
}

cmpthese(10000, align {
    'Bacon, Lettuce, & Tomato' => sub {...},
    'Ham on Rye'               => sub {...},
    'Spam'                     => sub {...},
    # etc.
});