def save_page(p)
      if p.record.page_entries != p.values.length
        raise RuntimeError, "page_entries mismatch for node #{p.uid}"
      end
      begin
        @f.seek(p.uid * @page_size * 8)
        @f.write(p.values.pack('Q*'))
      rescue IOError => e
        PEROBS.log.fatal "Cannot write cache file #{@file_name}: #{e.message}"
      end
    end
def save_page(p)
      if p.record.page_entries != p.values.length
        raise RuntimeError, "page_entries mismatch for node #{p.uid}"
      end
      begin
        @f.seek(p.uid * @page_size * 8)
        @f.write(p.values.pack('Q*'))
      rescue IOError => e
        PEROBS.log.fatal "Cannot write cache file #{@file_name}: #{e.message}"
      end
    end
Save the given IDListPage into the cache file.
 @param p [IDListPage] page to store