Set compression level when generating a ZIP file using RubyZip

I have a Ruby program that zips a directory tree of XML files using the rubyzip gem. My problem is that the file is starting to be heavy and I would like to increase the compression level, since c开发者_开发百科ompression time is not an issue.

I could not find in the rubyzip documentation a way to specify the compression level for the created ZIP file.

Anyone know how to change this setting? Is there another Ruby library that allows to specify compression level?

Here is the code I created by looking at rubyzip internal.

level = Zlib::BEST_COMPRESSION
Zip::ZipOutputStream.open(zip_file) do |zip|
    Dir.glob("**/*") do |filename|
        entry = Zip::ZipEntry.new("", filename)
        entry.gather_fileinfo_from_srcpath(filename)
        zip.put_next_entry(entry, nil, nil, Zip::ZipEntry::DEFLATED, level)
        entry.get_input_stream { |is| IOExtras.copy_stream(zip, is) }
    end
end

you'll probably get better traction by calling out to the 'zip' program or what not to do the zipping.