public void Grow(long bytesToGrow)
{
CheckDisposed();
if (bytesToGrow <= 0 || bytesToGrow % AllocationGranularity != 0)
{
throw new ArgumentException("The growth must be a multiple of 64Kb and greater than zero");
}
long offset = fs.Length;
fs.SetLength(fs.Length + bytesToGrow);
var mmf = MemoryMappedFile.CreateFromFile(fs, null, fs.Length, MemoryMappedFileAccess.ReadWrite, null, HandleInheritability.None, true);
uint *offsetPointer = (uint *)&offset;
var lastArea = areas[areas.Count - 1];
byte *desiredAddress = lastArea.Address + lastArea.Size;
var address = Win32FileMapping.MapViewOfFileEx(mmf.SafeMemoryMappedFileHandle.DangerousGetHandle(),
Win32FileMapping.FileMapAccess.Read | Win32FileMapping.FileMapAccess.Write,
offsetPointer[1], offsetPointer[0], new UIntPtr((ulong)bytesToGrow), desiredAddress);
if (address == null)
{
address = Win32FileMapping.MapViewOfFileEx(mmf.SafeMemoryMappedFileHandle.DangerousGetHandle(),
Win32FileMapping.FileMapAccess.Read | Win32FileMapping.FileMapAccess.Write,
offsetPointer[1], offsetPointer[0], new UIntPtr((ulong)bytesToGrow), null);
}
if (address == null)
{
throw new Win32Exception();
}
var area = new MemoryMappedArea {
Address = address,
Mmf = mmf,
Size = bytesToGrow
};
areas.Add(area);
if (desiredAddress != address)
{
offsets = offsets.Add(offset);
addresses = addresses.Add(address);
}
}
private void CreateFirstArea()
{
var mmf = MemoryMappedFile.CreateFromFile(fs, null, fs.Length, MemoryMappedFileAccess.ReadWrite, null, HandleInheritability.None, true);
var address = Win32FileMapping.MapViewOfFileEx(mmf.SafeMemoryMappedFileHandle.DangerousGetHandle(),
Win32FileMapping.FileMapAccess.Read | Win32FileMapping.FileMapAccess.Write,
0, 0, new UIntPtr((ulong)fs.Length), null);
if (address == null)
{
throw new Win32Exception();
}
var area = new MemoryMappedArea
{
Address = address,
Mmf = mmf,
Size = fs.Length
};
areas.Add(area);
addresses = new byte *[] { address };
offsets = new long[] { 0 };
}