Comparison of hash objects with packed objects (SvPV)

benchmark results

/opt/perl/5.13.11/bin/perl packed_vs_hash.pl 
Benchmarking constructor
         Rate hash pack
hash 445987/s   -- -10%
pack 496264/s  11%   --

Benchmarking accessor
          Rate  vec hash
vec  1190203/s   --  -9%
hash 1308227/s  10%   --

Benchmarking accessor (list of multiple attributes)
           Rate   hash unpack
hash   719228/s     --    -6%
unpack 762286/s     6%     --


/opt/perl/5.12.3/bin/perl packed_vs_hash.pl 
Benchmarking constructor
         Rate hash pack
hash 437788/s   -- -10%
pack 487507/s  11%   --

Benchmarking accessor
          Rate  vec hash
vec  1135525/s   --  -4%
hash 1184835/s   4%   --

Benchmarking accessor (list of multiple attributes)
           Rate   hash unpack
hash   675164/s     --    -9%
unpack 739499/s    10%     --


/opt/perl/5.10.1/bin/perl packed_vs_hash.pl 
Benchmarking constructor
         Rate hash pack
hash 433194/s   --  -8%
pack 468559/s   8%   --

Benchmarking accessor
          Rate  vec hash
vec  1145795/s   --  -4%
hash 1189297/s   4%   --

Benchmarking accessor (list of multiple attributes)
           Rate   hash unpack
hash   695712/s     --    -6%
unpack 740601/s     6%     --


/opt/perl/5.8.9/bin/perl packed_vs_hash.pl 
Benchmarking constructor
         Rate hash pack
hash 413896/s   -- -12%
pack 469801/s  14%   --

Benchmarking accessor
          Rate  vec hash
vec  1105099/s   --  -4%
hash 1148337/s   4%   --

Benchmarking accessor (list of multiple attributes)
           Rate   hash unpack
hash   659439/s     --    -2%
unpack 675623/s     2%     --


/opt/perl/5.6.2/bin/perl packed_vs_hash.pl 
Benchmarking constructor
Benchmark: running hash, pack, each for at least 10 CPU seconds...
      hash: 11 wallclock secs (10.53 usr +  0.16 sys = 10.69 CPU) @ 442920.95/s (n=4734825)
      pack: 11 wallclock secs (10.16 usr +  0.16 sys = 10.32 CPU) @ 525622.29/s (n=5424422)
         Rate hash pack
hash 442921/s   -- -16%
pack 525622/s  19%   --

Benchmarking accessor
Benchmark: running hash, vec, each for at least 10 CPU seconds...
      hash: 10 wallclock secs ( 9.95 usr +  0.10 sys = 10.05 CPU) @ 1414538.91/s (n=14216116)
       vec: 11 wallclock secs (10.56 usr +  0.18 sys = 10.74 CPU) @ 1293750.65/s (n=13894882)
          Rate  vec hash
vec  1293751/s   --  -9%
hash 1414539/s   9%   --

Benchmarking accessor (list of multiple attributes)
Benchmark: running hash, unpack, each for at least 10 CPU seconds...
      hash: 11 wallclock secs (10.41 usr +  0.14 sys = 10.55 CPU) @ 753014.12/s (n=7944299)
    unpack: 11 wallclock secs (10.17 usr +  0.12 sys = 10.29 CPU) @ 814110.88/s (n=8377201)
           Rate   hash unpack
hash   753014/s     --    -8%
unpack 814111/s     8%     --

packed_vs_hash.pl

#!/usr/bin/perl

use strict;
use warnings;

{
    package MyVec;

    sub new {
        my ($class, $y, $m, $d) = @_;
        return bless \pack('nCC', $y, $m, $d), $class;
    }

    sub year {
        my ($self) = @_;
        return vec($$self, 0, 16);
    }

    sub month {
        my ($self) = @_;
        return vec($$self, 2, 8);
    }

    sub day {
        my ($self) = @_;
        return vec($$self, 3, 8);
    }

    sub ymd {
        my ($self) = @_;
        return unpack('nCC', $$self);
    }
}

{
    package MyHash;

    sub new {
        my ($class, $y, $m, $d) = @_;
        return bless {
            year  => $y,
            month => $m,
            day   => $d,
        }, $class;
    }

    sub year {
        my ($self) = @_;
        return $self->{year};
    }

    sub month {
        my ($self) = @_;
        return $self->{month};
    }

    sub day {
        my ($self) = @_;
        return $self->{month};
    }

    sub ymd {
        my ($self) = @_;
        return @$self{qw(year month day)};
    }
}

use Benchmark qw[];

print "Benchmarking constructor\n";
Benchmark::cmpthese( -10, {
    'pack' => sub {
        my $vobj = MyVec->new(2009, 10, 12);
    },
    'hash' => sub {
        my $hobj = MyHash->new(2009, 10, 12);
    },
});

print "\nBenchmarking accessor\n";
my ($vobj, $hobj) = map { $_->new(2009, 10, 12) } qw(MyVec MyHash);
Benchmark::cmpthese( -10, {
    'vec' => sub {
        my $m = $vobj->month;
    },
    'hash' => sub {
        my $m = $hobj->month;
    },
});

print "\nBenchmarking accessor (list of multiple attributes)\n";
Benchmark::cmpthese( -10, {
    'unpack' => sub {
        my ($y, $m, $d) = $vobj->ymd;
    },
    'hash' => sub {
        my ($y, $m, $d) = $hobj->ymd;
    },
});