internal Sector GetOrReadSector(SectorPtr sectorPtr, bool inWriteTransaction, SectorTypeInit typeInit, Sector parent)
{
return TryGetSector(sectorPtr.Ptr, inWriteTransaction, parent) ??
ReadSector(sectorPtr, inWriteTransaction, typeInit, parent);
}
internal Sector ReadSector(SectorPtr sectorPtr, bool inWriteTransaction, SectorTypeInit typeInit, Sector parent)
{
Debug.Assert(sectorPtr.Ptr > 0);
return ReadSector(sectorPtr.Ptr & MaskOfPosition, (int)(sectorPtr.Ptr & MaskOfGranLength) + 1, sectorPtr.Checksum, inWriteTransaction, typeInit, parent);
}
Sector ReadSector(long position, int size, uint checksum, bool inWriteTransaction, SectorTypeInit typeInit, Sector parent)
{
if (position <= 0) throw new BTDBException("Wrong data in db (negative position)");
if (size <= 0 || size > MaxSectorSize / AllocationGranularity) throw new BTDBException("Wrong sector length");
TruncateSectorCache(inWriteTransaction, parent != null ? parent.Position : 0);
lock (_readSectorLock)
{
Sector sector = TryGetSector(position,inWriteTransaction,parent);
if (sector != null) return sector;
size = size * AllocationGranularity;
sector = new Sector { Position = position, Length = size, InternalLastAccessTime = 0, Parent = parent };
if (inWriteTransaction)
{
sector.InTransaction = _spaceAllocatedInTransaction.Contains((ulong)position);
if (sector.InTransaction)
LinkToTailOfInTransactionSectors(sector);
}
//Console.WriteLine("Reading {0} len:{1}", position, size);
if (_positionLessStream.Read(sector.Data, 0, size, (ulong)position) != size)
{
throw new BTDBException("Data reading error");
}
Interlocked.Add(ref _totalBytesRead, size);
if (Checksum.CalcFletcher32(sector.Data, 0, (uint)size) != checksum)
{
throw new BTDBException("Checksum error");
}
switch (typeInit)
{
case SectorTypeInit.AllocChild:
sector.Type = SectorType.AllocChild;
break;
case SectorTypeInit.AllocParent:
sector.Type = SectorType.AllocParent;
break;
case SectorTypeInit.DataParent:
sector.Type = SectorType.DataParent;
break;
case SectorTypeInit.DataChild:
sector.Type = SectorType.DataChild;
break;
case SectorTypeInit.BTreeChildOrParent:
sector.Type = BTreeChildIterator.IsChildFromSectorData(sector.Data)
? SectorType.BTreeChild
: SectorType.BTreeParent;
break;
default:
throw new InvalidOperationException();
}
LowLevelAddToSectorCache(sector);
UpdateLastAccess(sector);
if (inWriteTransaction)
{
sector.Parent = parent;
}
return sector;
}
}
