public static UsnJrnl[] GetInstances(string volume)
{
// Check for valid Volume name
NativeMethods.getVolumeName(ref volume);
// Set up FileStream to read volume
IntPtr hVolume = NativeMethods.getHandle(volume);
FileStream streamToRead = NativeMethods.getFileStream(hVolume);
// Get VolumeBootRecord object for logical addressing
VolumeBootRecord VBR = VolumeBootRecord.Get(streamToRead);
// Get the $J Data attribute (contains UsnJrnl details
NonResident J = UsnJrnl.GetJStream(UsnJrnl.GetFileRecord(volume));
List <UsnJrnl> usnList = new List <UsnJrnl>();
for (int i = 0; i < J.DataRun.Length; i++)
{
if (!(J.DataRun[i].Sparse))
{
long clusterCount = J.DataRun[i].ClusterLength;
byte[] fragmentBytes = NativeMethods.readDrive(streamToRead, ((ulong)J.DataRun[i].StartCluster * VBR.BytesPerCluster), ((ulong)clusterCount * VBR.BytesPerCluster));
byte[] clusterBytes = new byte[VBR.BytesPerCluster];
for (long j = 0; j < clusterCount; j++)
{
Array.Copy(fragmentBytes, ((long)j * VBR.BytesPerCluster), clusterBytes, 0, clusterBytes.Length);
int offset = 0;
do
{
if (clusterBytes[offset] == 0)
{
break;
}
try
{
UsnJrnl usn = new UsnJrnl(clusterBytes, volume, ref offset);
if (usn.Version > USN40Version)
{
break;
}
usnList.Add(usn);
}
catch
{
break;
}
} while (offset >= 0 && offset < clusterBytes.Length);
}
}
}
return(usnList.ToArray());
}
public static UsnJrnl Get(string volume, ulong usn)
{
// Check for valid Volume name
NativeMethods.getVolumeName(ref volume);
// Set up FileStream to read volume
IntPtr hVolume = NativeMethods.getHandle(volume);
FileStream streamToRead = NativeMethods.getFileStream(hVolume);
// Get VolumeBootRecord object for logical addressing
VolumeBootRecord VBR = VolumeBootRecord.Get(streamToRead);
// Get the $J Data attribute (contains UsnJrnl details
NonResident J = UsnJrnl.GetJStream(UsnJrnl.GetFileRecord(volume));
// Determine the length of the initial sparse pages
ulong SparseLength = (ulong)J.DataRun[0].ClusterLength * VBR.BytesPerCluster;
// Subtract length of sparse data from desired usn offset
ulong usnOffset = usn - SparseLength;
// Iterate through each data run
for (int i = 1; i < J.DataRun.Length; i++)
{
// Determine length of current DataRun
ulong dataRunLength = (ulong)J.DataRun[i].ClusterLength * VBR.BytesPerCluster;
// Check if usnOffset resides in current DataRun
if (dataRunLength <= usnOffset)
{
// If not, subtract length of DataRun from usnOffset
usnOffset -= dataRunLength;
}
// If usnOffset resides within DataRun, parse associated UsnJrnl Entry
else
{
// Read DataRun from disk
byte[] fragmentBytes = NativeMethods.readDrive(streamToRead, ((ulong)J.DataRun[i].StartCluster * VBR.BytesPerCluster), ((ulong)J.DataRun[i].ClusterLength * VBR.BytesPerCluster));
// Instatiate a byte array that is the size of a single cluster
byte[] clusterBytes = new byte[VBR.BytesPerCluster];
// Iterate through the clusters in the DataRun
for (long j = 0; j < J.DataRun[i].ClusterLength; j++)
{
// If usnOffset is not in current cluster, then subtract cluster size from offset and iterate
if (VBR.BytesPerCluster <= usnOffset)
{
usnOffset -= VBR.BytesPerCluster;
}
// Else if usnOffset is in current cluster
else
{
// Copy current cluster bytes to clusterBytes variable
Array.Copy(fragmentBytes, ((long)j * VBR.BytesPerCluster), clusterBytes, 0, clusterBytes.Length);
// Parse desired UsnJrnl entry from cluster
int offset = (int)usnOffset;
return(new UsnJrnl(clusterBytes, volume, ref offset));
}
}
}
}
return(null);
}