private NPOIFSFileSystem(bool newFS)
{
_header = new HeaderBlock(bigBlockSize);
_property_table = new NPropertyTable(_header);
_mini_store = new NPOIFSMiniStore(this, _property_table.Root, new List<BATBlock>(), _header);
_xbat_blocks = new List<BATBlock>();
_bat_blocks = new List<BATBlock>();
_root = null;
if (newFS)
{
// Data needs to Initially hold just the header block,
// a single bat block, and an empty properties section
_data = new ByteArrayBackedDataSource(new byte[bigBlockSize.GetBigBlockSize() * 3]);
}
}
/**
* Read and process the PropertiesTable and the
* FAT / XFAT blocks, so that we're Ready to
* work with the file
*/
private void ReadCoreContents()
{
// Grab the block size
bigBlockSize = _header.BigBlockSize;
// Each block should only ever be used by one of the
// FAT, XFAT or Property Table. Ensure it does
ChainLoopDetector loopDetector = GetChainLoopDetector();
// Read the FAT blocks
foreach (int fatAt in _header.BATArray)
{
ReadBAT(fatAt, loopDetector);
}
// Work out how many FAT blocks remain in the XFATs
int remainingFATs = _header.BATCount - _header.BATArray.Length;
// Now read the XFAT blocks, and the FATs within them
BATBlock xfat;
int nextAt = _header.XBATIndex;
for (int i = 0; i < _header.XBATCount; i++)
{
loopDetector.Claim(nextAt);
ByteBuffer fatData = GetBlockAt(nextAt);
xfat = BATBlock.CreateBATBlock(bigBlockSize, fatData);
xfat.OurBlockIndex = nextAt;
nextAt = xfat.GetValueAt(bigBlockSize.GetXBATEntriesPerBlock());
_xbat_blocks.Add(xfat);
// Process all the (used) FATs from this XFAT
int xbatFATs = Math.Min(remainingFATs, bigBlockSize.GetXBATEntriesPerBlock());
for(int j=0; j<xbatFATs; j++)
{
int fatAt = xfat.GetValueAt(j);
if (fatAt == POIFSConstants.UNUSED_BLOCK || fatAt == POIFSConstants.END_OF_CHAIN) break;
ReadBAT(fatAt, loopDetector);
}
remainingFATs -= xbatFATs;
}
// We're now able to load steams
// Use this to read in the properties
_property_table = new NPropertyTable(_header, this);
// Finally read the Small Stream FAT (SBAT) blocks
BATBlock sfat;
List<BATBlock> sbats = new List<BATBlock>();
_mini_store = new NPOIFSMiniStore(this, _property_table.Root, sbats, _header);
nextAt = _header.SBATStart;
for (int i = 0; i < _header.SBATCount; i++)
{
loopDetector.Claim(nextAt);
ByteBuffer fatData = GetBlockAt(nextAt);
sfat = BATBlock.CreateBATBlock(bigBlockSize, fatData);
sfat.OurBlockIndex = nextAt;
sbats.Add(sfat);
nextAt = GetNextBlock(nextAt);
}
}