module Qeweney::ResponseMethods

def serve_io_gzip(io, opts)
  buf = StringIO.new
  z = Zlib::GzipWriter.new(buf)
  z << io.read
  z.flush
  z.close
  headers = opts[:headers].merge(
    'content-encoding' => 'gzip',
    'vary' => 'Accept-Encoding'
  )
  respond(buf.string, headers)
end