/// <summary>
        /// Fetch a directory to build the internal index (recursive)
        /// </summary>
        private void AddDirectoryToIndex(DataTrackIndexEntry indexDirectoryEntry)
        {
            DirectoryEntry      entry;
            DataTrackIndexEntry indexEntry;
            long lba          = indexDirectoryEntry.DirectoryEntry.ExtentLba;
            long size         = indexDirectoryEntry.DirectoryEntry.ExtentSize;
            int  sectorsCount = (int)(size / GetSectorDataSize(_defaultSectorMode));

            var stream = new CBinaryReader(ReadSectors(lba, sectorsCount, _defaultSectorMode));

            // First directory entry of a directory entry is the directory itself, so let's skip it
            ReadDirectoryEntry(stream);

            // Second directory entry is the parent directory entry.
            // As we parse the data from root to children, it has already been handled, so let's skip it too
            ReadDirectoryEntry(stream);

            while (stream.Position < size)
            {
                short b = stream.TestByte();

                if (b == 0)
                {
                    // DirectoryEntry cannot be "splitted" on two sectors
                    int dataSize = GetSectorDataSize(_defaultSectorMode);
                    stream.Position = (((stream.Position / dataSize) + 1) * dataSize);
                    b = stream.TestByte();
                }

                if (b <= 0)
                {
                    break;
                }
                else
                {
                    entry = ReadDirectoryEntry(stream);

                    indexEntry = new DataTrackIndexEntry(indexDirectoryEntry, entry);
                    _index.AddToIndex(indexEntry);

                    if (indexEntry.IsDirectory)
                    {
                        AddDirectoryToIndex(indexEntry);
                    }
                }
            }

            stream.CloseAndDispose();
        }