/// <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);
}