class ActiveStorage::Service::DiskService

def download(key)
  if block_given?
    instrument :streaming_download, key: key do
      File.open(path_for(key), "rb") do |file|
        while data = file.read(5.megabytes)
          yield data
        end
      end
    end
  else
    instrument :download, key: key do
      File.binread path_for(key)
    end
  end
end