zip_streamer.rb

class MyApp < Sinatra::Base
  FILE_PATHS = [
    'document.pdf',
    'movie.mov'
  ]
  get "/zip" do
    body = ZipStreamer.make_streaming_body(file_paths: file_paths)
    headers = {'Transfer-Encoding' => 'chunked', 'Content-Disposition' => 'attachment; filename="myzip.zip"'}
    [200,headers,body]
  end
end
class ZipStreamer
  def self.make_streaming_body(file_paths: )
    ZipTricks::RackBody.new do |file|
      file_paths.each do |file_path|
        zip.write_stored_file(file_path) do |sink|
          File.open(file_path, 'rb'){
            |source| IO.copy_stream(source, sink)
          }
        end
      end
    end
  end
end