protected void RollOverTime()

in src/log4net/Appender/RollingFileAppender.cs [1058:1107]
34 lines of code
7 McCabe index (conditional complexity)

  protected void RollOverTime(bool fileIsOpen)
  {
    if (StaticLogFileName)
    {
      // Compute filename, but only if datePattern is specified
      if (DatePattern is null)
      {
        ErrorHandler.Error("Missing DatePattern option in rollOver().");
        return;
      }

      //is the new file name equivalent to the 'current' one
      //something has gone wrong if we hit this -- we should only
      //roll over if the new file will be different from the old
      string dateFormat = _now.ToString(DatePattern, DateTimeFormatInfo.InvariantInfo);
      if (string.Equals(_scheduledFilename, CombinePath(File!, dateFormat), StringComparison.Ordinal))
      {
        ErrorHandler.Error($"Compare {_scheduledFilename} : {CombinePath(File!, dateFormat)}");
        return;
      }

      if (fileIsOpen)
      {
        // close current file, and rename it to datedFilename
        CloseFile();
      }

      //we may have to roll over a large number of backups here
      for (int i = 1; i <= CurrentSizeRollBackups; i++)
      {
        string from = CombinePath(File!, "." + i);
        string to = CombinePath(_scheduledFilename!, "." + i);
        RollFile(from, to);
      }

      RollFile(File!, _scheduledFilename!);
    }

    //We've cleared out the old date and are ready for the new
    CurrentSizeRollBackups = 0;

    //new scheduled name
    _scheduledFilename = CombinePath(File!, _now.ToString(DatePattern, DateTimeFormatInfo.InvariantInfo));

    if (fileIsOpen)
    {
      // This will also close the file. This is OK since multiple close operations are safe.
      SafeOpenFile(_baseFileName!, false);
    }
  }