# snip...
sub _lock_meta
{
    my $self = shift;
    my $mode = shift || 'r';

    my $meta_name = do {
        unless (exists $self->{metaname})
        {
            $self->{metaname} = File::Spec->catfile($self->{path}, 'me
+ta.info');
        }
        $self->{metaname};
    };

    my $fh = IO::File->new($meta_name, $mode);
    if ($fh)
    {
        flock($fh, $mode eq 'r' ? LOCK_SH : LOCK_EX);
    }
    $fh;
}

sub _load_meta
{
    my $self = shift;
    my $fh   = $self->_lock_meta();

    # only load it if it's been changed since the last load.
    my $s = stat($self->{metaname});
    if ($s and
        $s->mtime() >= ($self->{metastamp} || 0) and
        $fh)
    {
        local $/;
        my $data = join '', $fh->getlines();
        $self->{metastamp} = time();
        $fh->close(); # release lock

        $self->{meta} = $self->_thaw($data);
    }
}

sub _save_meta
{
    my $self = shift;
    my $fh   = $self->_lock_meta('w');

    $fh->print($self->_freeze($self->{meta}));
    $fh->close();
}

sub _thaw
{
    my $self = shift;
    my $data = shift;
    eval 'my ' . $data;
}

sub _freeze
{
    my $self = shift;
    my $data = shift;
    require Data::Dumper;
    local $Data::Dumper::Indent = 0;
    join '', Data::Dumper::Dumper($data);
}

# snip...
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