HTML/CSS/JS Minification, Perl module

package Minify;
use nginx;
use JavaScript::Minifier::XS;
use CSS::Minifier::XS;
use HTML::Packer;

sub css_handler {
    my $r = shift;
    my $cache_file = $r->filename . ".min.css";
    my $filename = $r->filename;
    local $/=undef;

    return DECLINED unless -f $filename;

    open(INFILE, $filename) or die "Error reading file: $!";
    my $css = <INFILE>;
    close(INFILE);

    open(OUTFILE, '>' . $cache_file) or die "Error writing file: $!";
    print OUTFILE CSS::Minifier::XS::minify($css);
    close(OUTFILE);

    $r->send_http_header('text/css');
    $r->sendfile($cache_file);
    return OK;
}

sub js_handler {
    my $r = shift;
    my $cache_file = $r->filename . ".min.js";
    my $filename = $r->filename;
    local $/=undef;

    return DECLINED unless -f $filename;

    open(INFILE, $filename) or die "Error reading file: $!";
    my $js = <INFILE>;
    close(INFILE);

    open(OUTFILE, '>' . $cache_file) or die "Error writing file: $!";
    print OUTFILE JavaScript::Minifier::XS::minify($js);
    close(OUTFILE);

    $r->send_http_header('application/javascript');
    $r->sendfile($cache_file);
    return OK;
}

sub html_handler {
    my $r = shift;
    my $cache_file = $r->filename . ".min.html";
    my $filename = $r->filename;
    local $/=undef;

    return DECLINED unless -f $filename;

    open(INFILE, $filename) or die "Error reading file: $!";
    my $html = <INFILE>;
    close(INFILE);

    open(OUTFILE, '>' . $cache_file) or die "Error writing file: $!";
    print OUTFILE HTML::Packer::minify($html, {remove_comments => 1, remove_newlines => 1, no_compress_comment => 1, html5 => 1, do_javascript => 'clean', do_stylesheet => 'minify'});
    close(OUTFILE);

    $r->send_http_header('text/html');
    $r->sendfile($cache_file);
    return OK;
}

1;