def setUploadRatio(infoHash, ratio)
      torrentData = @torrentData[infoHash]
      if ! torrentData
        @logger.warn "Asked to set upload ratio limit for a non-existent torrent #{QuartzTorrent.bytesToHex(infoHash)}"
        return
      end

      torrentData.ratio = ratio
    end
def setUploadRatio(infoHash, ratio)
      torrentData = @torrentData[infoHash]
      if ! torrentData
        @logger.warn "Asked to set upload ratio limit for a non-existent torrent #{QuartzTorrent.bytesToHex(infoHash)}"
        return
      end

      torrentData.ratio = ratio
    end
Set the upload ratio. Pass nil to disable