/// <remarks>
/// https://blogs.technet.microsoft.com/askcore/2009/10/16/the-four-stages-of-ntfs-file-growth/
/// </remarks>
public void UpdateSegments(int bytesPerFileRecordSegment, byte minorNTFSVersion)
{
m_segments[0].ReferenceCount = ReferenceCount;
m_segments[0].IsInUse = IsInUse;
m_segments[0].IsDirectory = IsDirectory;
List <AttributeRecord> attributes = this.Attributes;
foreach (FileRecordSegment segment in m_segments)
{
segment.ImmediateAttributes.Clear();
segment.NextAttributeInstance = 0;
}
int segmentLength = bytesPerFileRecordSegment - FileRecordSegment.GetNumberOfBytesAvailable(bytesPerFileRecordSegment, minorNTFSVersion);
foreach (AttributeRecord attribute in attributes)
{
segmentLength += (int)attribute.RecordLength;
}
if (segmentLength <= bytesPerFileRecordSegment)
{
// A single record segment is needed
foreach (AttributeRecord attribute in attributes)
{
m_segments[0].AddAttributeRecord(attribute.Clone());
}
// Free the rest of the segments, if there are any
for (int index = 1; index < m_segments.Count; index++)
{
m_segments[index].IsInUse = false;
}
}
else
{
// We slice the attributes and put them in segments, the attribute list will be built by the caller after the new segments will be allocated
FileRecordHelper.SliceAttributes(m_segments, attributes, bytesPerFileRecordSegment, minorNTFSVersion);
}
}
/// <remarks>
/// An attribute list MUST be sorted by AttributeType with a secondary sort by AttributeName.
/// </remarks>
public static List <AttributeListEntry> BuildAttributeList(List <FileRecordSegment> segments, int bytesPerFileRecordSegment, ushort minorNTFSVersion)
{
int bytesAvailableInSegment = FileRecordSegment.GetNumberOfBytesAvailable(bytesPerFileRecordSegment, minorNTFSVersion);
List <AttributeListEntry> result = new List <AttributeListEntry>();
foreach (FileRecordSegment segment in segments)
{
foreach (AttributeRecord attribute in segment.ImmediateAttributes)
{
AttributeListEntry entry = new AttributeListEntry();
entry.AttributeType = attribute.AttributeType;
if (attribute is NonResidentAttributeRecord)
{
entry.LowestVCN = ((NonResidentAttributeRecord)attribute).LowestVCN;
}
entry.SegmentReference = segment.SegmentReference;
entry.Instance = attribute.Instance;
entry.AttributeName = attribute.Name;
result.Add(entry);
}
}
return(result);
}
public static void SliceAttributes(List <FileRecordSegment> segments, List <AttributeRecord> attributes, int bytesPerFileRecordSegment, ushort minorNTFSVersion)
{
int bytesAvailableInSegment = FileRecordSegment.GetNumberOfBytesAvailable(bytesPerFileRecordSegment, minorNTFSVersion);
LinkedList <KeyValuePair <AttributeRecord, bool> > remainingAttributes = new LinkedList <KeyValuePair <AttributeRecord, bool> >();
FileRecordSegment baseFileRecordSegment = segments[0];
long segmentNumber = baseFileRecordSegment.SegmentNumber;
bool isMftFileRecord = (segmentNumber == MasterFileTable.MasterFileTableSegmentNumber || segmentNumber == MasterFileTable.MftMirrorSegmentNumber);
foreach (AttributeRecord attribute in attributes)
{
if (attribute.AttributeType == AttributeType.StandardInformation ||
attribute.AttributeType == AttributeType.FileName)
{
baseFileRecordSegment.ImmediateAttributes.Add(attribute);
}
else if (isMftFileRecord && attribute.AttributeType == AttributeType.Data)
{
List <NonResidentAttributeRecord> slices = SliceAttributeRecord((NonResidentAttributeRecord)attribute, bytesPerFileRecordSegment / 2, bytesAvailableInSegment);
baseFileRecordSegment.ImmediateAttributes.Add(slices[0]);
slices.RemoveAt(0);
foreach (NonResidentAttributeRecord slice in slices)
{
remainingAttributes.AddLast(new KeyValuePair <AttributeRecord, bool>(slice, true));
}
}
else
{
remainingAttributes.AddLast(new KeyValuePair <AttributeRecord, bool>(attribute, false));
}
}
int segmentIndex = 1;
int remainingLengthInCurrentSegment = bytesAvailableInSegment;
while (remainingAttributes.Count > 0)
{
AttributeRecord attribute = remainingAttributes.First.Value.Key;
bool isSlice = remainingAttributes.First.Value.Value;
if (segmentIndex == segments.Count)
{
MftSegmentReference newSegmentReference = MftSegmentReference.NullReference;
FileRecordSegment newFileRecordSegment = new FileRecordSegment(newSegmentReference.SegmentNumber, newSegmentReference.SequenceNumber, baseFileRecordSegment.SegmentReference);
newFileRecordSegment.IsInUse = true;
segments.Add(newFileRecordSegment);
}
if (attribute.RecordLength <= remainingLengthInCurrentSegment)
{
remainingLengthInCurrentSegment -= (int)attribute.RecordLength;
segments[segmentIndex].ImmediateAttributes.Add(attribute);
remainingAttributes.RemoveFirst();
// Instead of renumbering each attribute slice in the new FileRecordSegment, we use the original Instance number.
if (segments[segmentIndex].NextAttributeInstance <= attribute.Instance)
{
segments[segmentIndex].NextAttributeInstance = (ushort)(attribute.Instance + 1);
}
}
else
{
if (attribute is ResidentAttributeRecord || isSlice)
{
segmentIndex++;
remainingLengthInCurrentSegment = bytesAvailableInSegment;
}
else
{
NonResidentAttributeRecord nonResidentAttribute = ((NonResidentAttributeRecord)attribute);
List <NonResidentAttributeRecord> slices = SliceAttributeRecord((NonResidentAttributeRecord)attribute, remainingLengthInCurrentSegment, bytesAvailableInSegment);
remainingAttributes.RemoveFirst();
slices.Reverse();
foreach (NonResidentAttributeRecord slice in slices)
{
remainingAttributes.AddFirst(new KeyValuePair <AttributeRecord, bool>(slice, true));
}
}
}
}
}
