docs: def doRollover(self):
          """
          do a rollover; in this case, a date/time stamp is appended to the filename
          when the rollover happens.  However, you want the file to be named for the
          start of the interval, not the current time.  If there is a backup count,
          then we have to get a list of matching filenames, sort them and remove
          the one with the oldest suffix.
          """
          # if self.stream:
          #    self.stream.close()
          # get the time that this sequence started at and make it a TimeTuple
          t = self.rolloverAt - self.interval
          if self.utc:
              timeTuple = time.gmtime(t)
          else:
              timeTuple = time.localtime(t)
          dfn = self.baseFilename + "." + time.strftime(self.suffix, timeTuple)
          # if os.path.exists(dfn):
          #    os.remove(dfn)
          lockdata = struct.pack('hhllhh', fcntl.F_WRLCK, 0, 0, 0, 0, 0)
          fcntl.fcntl(self.stream, fcntl.F_SETLKW, lockdata)
          if not os.path.exists(dfn) and os.path.exists(self.baseFilename):
              os.rename(self.baseFilename, dfn)
              with open(self.baseFilename, 'a'):
                  pass
          if self.backupCount > 0:
              # find the oldest log file and delete it
              # s = glob.glob(self.baseFilename + ".20*")
              # if len(s) > self.backupCount:
              #    s.sort()
              #    os.remove(s[0])
              for s in self.getFilesToDelete():
                  os.remove(s)
          # print "%s -> %s" % (self.baseFilename, dfn)
          if self.stream:
              self.stream.close()
          self.mode = 'a'
          self.stream = self._open()
          currentTime = int(time.time())
          newRolloverAt = self.computeRollover(currentTime)
          while newRolloverAt <= currentTime:
              newRolloverAt = newRolloverAt + self.interval
          # If DST changes and midnight or weekly rollover, adjust for this.
          if (self.when == 'MIDNIGHT' or self.when.startswith('W')) and not self.utc:
              dstNow = time.localtime(currentTime)[-1]
              dstAtRollover = time.localtime(newRolloverAt)[-1]
              if dstNow != dstAtRollover:
                  if not dstNow:  # DST kicks in before next rollover, so we need to deduct an hour
                      newRolloverAt = newRolloverAt - 3600
                  else:  # DST bows out before next rollover, so we need to add an hour
                      newRolloverAt = newRolloverAt + 3600
          self.rolloverAt = newRolloverAt