Hash key access

hash-key-access.pl

use strict;
use warnings;
use Benchmark qw(cmpthese);

sub hv {
    my ($ref, $key, $default) = @_;
    defined $ref && exists $ref->{$key} ? $ref->{$key} : $default;
}

my $hash = {
    position => 9,
};

cmpthese(2_000_000, {
    'Local var' => sub {
        if (my $pos = hv($hash, 'position')) {
            $pos;
        }
    },
    'Direct hash access' => sub {
        if (hv($hash, 'position')) {
            $hash->{position};
        }
    },
    'Double hv() call' => sub {
        if (hv($hash, 'position')) {
            hv($hash, 'position');
        }
    },
});

=pod

                        Rate Double vh() call       Local var Direct hash access
Double vh() call   1169591/s               --            -46%               -55%
Local var          2150538/s              84%              --               -17%
Direct hash access 2597403/s             122%             21%                 --