Mojo after_static caching gzip

use IO::Compress::Gzip qw(gzip);

$self->hook(after_static => sub {
    my $c = shift;

    #only gzip if config allows it.
    return unless $c->config->{'gzip_static'};

    return unless ($c->req->headers->accept_encoding // '') =~ /gzip/i;

    $c->res->headers->append(Vary => 'Accept-Encoding');

    # Compress content with gzip
    $c->res->headers->content_encoding('gzip');

    if ($c->res->content->asset->can('path')) {
        my $path = $c->res->content->asset->path;
        my $gzpath = "$path.gz";

        if (! -e $gzpath || (stat($path))[9] > (stat($gzpath))[9]) {
            gzip $path, $gzpath;
        }

        $c->res->content->asset(Mojo::Asset::File->new(path => $gzpath));
    }

});