private void AddMapping(long offset, long qwOffset, long length)
{
var mapping = MemoryMappedFile.CreateFromFile(fileStream, null, length, MemoryMappedFileAccess.ReadWrite,
null, HandleInheritability.None, true);
var lastArea = areas[areas.Count - 1];
long *desiredAddress = lastArea.Address + lastArea.Length;
long *address = MapViewOfFileEx(mapping.SafeMemoryMappedFileHandle.DangerousGetHandle(),
FileMapAccess.Read | FileMapAccess.Write, (uint)(offset >> 32), (uint)offset,
new UIntPtr((ulong)offset), (byte *)desiredAddress);
if (address == null)
{
//if we cannot extend region to map file, let OS choose address to map
address = MapViewOfFileEx(mapping.SafeMemoryMappedFileHandle.DangerousGetHandle(),
FileMapAccess.Read | FileMapAccess.Write, (uint)(offset >> 32), (uint)offset,
new UIntPtr((ulong)offset), null);
}
if (address == null)
{
throw new Win32Exception();
}
var area = new MemoryMappedArea {
Address = address,
File = mapping,
Length = qwOffset
};
areas.Add(area);
if (desiredAddress != address)
{
offsets.Add(qwOffset);
addresses = Add(addresses, address);
}
}
internal static MemoryMapping Grow(long bytesToGrow, MemoryMapping mapping)
{
if (bytesToGrow <= 0 || bytesToGrow % Constants.AllocationGranularity != 0)
{
throw new ArgumentException("The growth must be a multiple of 64Kb and greater than zero");
}
long offset = mapping.fileStream.Length;
mapping.fileStream.SetLength(mapping.fileStream.Length + bytesToGrow);
var mmf = MemoryMappedFile.CreateFromFile(mapping.fileStream, null, mapping.fileStream.Length, MemoryMappedFileAccess.ReadWrite, HandleInheritability.None, true);
uint *offsetPointer = (uint *)&offset;
var lastArea = mapping.areas[mapping.areas.Count - 1];
byte *desiredAddress = lastArea.Address + lastArea.Size;
ulong bytesToMap = (ulong)bytesToGrow;
var address = Win32FileMapping.MapViewOfFileEx(mmf.SafeMemoryMappedFileHandle.DangerousGetHandle(),
Win32FileMapping.FileMapAccess.Read | Win32FileMapping.FileMapAccess.Write,
offsetPointer[1], offsetPointer[0], new UIntPtr(bytesToMap), desiredAddress);
if (address == null)
{
bytesToMap = (ulong)mapping.fileStream.Length;
address = Win32FileMapping.MapViewOfFileEx(mmf.SafeMemoryMappedFileHandle.DangerousGetHandle(),
Win32FileMapping.FileMapAccess.Read | Win32FileMapping.FileMapAccess.Write,
0, 0, new UIntPtr(bytesToMap), null);
if (address == null)
{
throw new Win32Exception();
}
mapping = new MemoryMapping()
{
baseAddress = address,
fileStream = mapping.fileStream,
refCount = 1
};
}
var area = new MemoryMappedArea
{
Address = address,
Mmf = mmf,
Size = (long)bytesToMap
};
mapping.areas.Add(area);
return(mapping);
}
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 };
}
