/// <summary> /// Constructs FAT table from list of sectors /// </summary> /// <param name="hdr">XlsHeader</param> /// <param name="sectors">Sectors list</param> /// <param name="sizeOfSector"></param> /// <param name="isMini"></param> /// <param name="rootDir"></param> public XlsFat(XlsHeader hdr, List <uint> sectors, int sizeOfSector, bool isMini, XlsRootDirectory rootDir) { m_isMini = isMini; m_rootDir = rootDir; m_hdr = hdr; m_sectors_for_fat = sectors.Count; sizeOfSector = hdr.SectorSize; uint sector = 0, prevSector = 0; //calc offset of stream . If mini stream then find mini stream container stream //long offset = 0; //if (rootDir != null) // offset = isMini ? (hdr.MiniFatFirstSector + 1) * hdr.SectorSize : 0; byte[] buff = new byte[sizeOfSector]; Stream file = hdr.FileStream; using (MemoryStream ms = new MemoryStream(sizeOfSector * m_sectors_for_fat)) { lock (file) { for (int i = 0; i < sectors.Count; i++) { sector = sectors[i]; if (prevSector == 0 || (sector - prevSector) != 1) { file.Seek((sector + 1) * sizeOfSector, SeekOrigin.Begin); } prevSector = sector; file.Read(buff, 0, sizeOfSector); ms.Write(buff, 0, sizeOfSector); } } ms.Seek(0, SeekOrigin.Begin); BinaryReader rd = new BinaryReader(ms); m_sectors = (int)ms.Length / 4; m_fat = new List <uint>(m_sectors); for (int i = 0; i < m_sectors; i++) { m_fat.Add(rd.ReadUInt32()); } rd.Dispose(); ms.Dispose(); } }
public void CalculateMiniFat(XlsRootDirectory rootDir) { m_minifat = m_hdr.GetMiniFAT(rootDir); }