public string DirectoryFromFrn(UInt64 frn)
{
string res = "";
if (frn == 0)
{
return(res);
}
while (true)
{
FileNameAndFrn cur = _directories[frn];
if (cur.ParentFrn == 0)
{
res = cur.Name + res;
break;
}
else
{
if (res.Length > 0)
{
res = @"\" + res;
}
res = cur.Name + res;
frn = cur.ParentFrn;
}
}
return(res);
}
/*
* private void GetRootFrnEntry()
* {
* string driveRoot = string.Concat("\\\\.\\", _drive);
* driveRoot = string.Concat(driveRoot, Path.DirectorySeparatorChar);
* IntPtr hRoot = PInvokeWin32.CreateFile(driveRoot,
* 0,
* PInvokeWin32.FILE_SHARE_READ | PInvokeWin32.FILE_SHARE_WRITE,
* IntPtr.Zero,
* PInvokeWin32.OPEN_EXISTING,
* PInvokeWin32.FILE_FLAG_BACKUP_SEMANTICS,
* IntPtr.Zero);
*
* if (hRoot.ToInt32() != PInvokeWin32.INVALID_HANDLE_VALUE)
* {
* PInvokeWin32.BY_HANDLE_FILE_INFORMATION fi = new PInvokeWin32.BY_HANDLE_FILE_INFORMATION();
* bool bRtn = PInvokeWin32.GetFileInformationByHandle(hRoot, out fi);
* if (bRtn)
* {
* UInt64 fileIndexHigh = (UInt64)fi.FileIndexHigh;
* UInt64 indexRoot = (fileIndexHigh << 32) | fi.FileIndexLow;
*
* FileNameAndFrn f = new FileNameAndFrn(driveRoot, 0);
* _directories.Add(indexRoot, f);
* }
* else
* {
* throw new IOException("GetFileInformationbyHandle() returned invalid handle",
* new Win32Exception(Marshal.GetLastWin32Error()));
* }
* PInvokeWin32.CloseHandle(hRoot);
* }
* else
* {
* throw new IOException("Unable to get root frn entry", new Win32Exception(Marshal.GetLastWin32Error()));
* }
* }
*/
private void GetRootFrnEntry()
{
string driveRoot = string.Concat("\\\\.\\", _drive);
driveRoot = string.Concat(driveRoot, Path.DirectorySeparatorChar);
UInt64 frn = FrnFromPath(driveRoot);
if (frn != 0)
{
FileNameAndFrn f = new FileNameAndFrn(driveRoot, 0);
_directories.Add(frn, f);
}
else
{
throw new IOException("Unable to get Root frn entry");
}
}
unsafe private void EnumerateFiles(IntPtr medBuffer, ref Dictionary <ulong, FileNameAndFrn> files, string[] fileExtensions)
{
IntPtr pData = Marshal.AllocHGlobal(sizeof(UInt64) + 0x10000);
PInvokeWin32.ZeroMemory(pData, sizeof(UInt64) + 0x10000);
uint outBytesReturned = 0;
while (false != PInvokeWin32.DeviceIoControl(_changeJournalRootHandle, PInvokeWin32.FSCTL_ENUM_USN_DATA, medBuffer,
sizeof(PInvokeWin32.MFT_ENUM_DATA), pData, sizeof(UInt64) + 0x10000, out outBytesReturned,
IntPtr.Zero))
{
IntPtr pUsnRecord = new IntPtr(pData.ToInt32() + sizeof(Int64));
while (outBytesReturned > 60)
{
PInvokeWin32.USN_RECORD usn = new PInvokeWin32.USN_RECORD(pUsnRecord);
if (0 != (usn.FileAttributes & PInvokeWin32.FILE_ATTRIBUTE_DIRECTORY))
{
//
// handle directories
//
if (!_directories.ContainsKey(usn.FileReferenceNumber))
{
_directories.Add(usn.FileReferenceNumber,
new FileNameAndFrn(usn.FileName, usn.ParentFileReferenceNumber));
}
else
{ // this is debug code and should be removed when we are certain that
// duplicate frn's don't exist on a given drive. To date, this exception has
// never been thrown. Removing this code improves performance....
throw new Exception(string.Format("Duplicate FRN: {0} for {1}",
usn.FileReferenceNumber, usn.FileName));
}
}
else
{
//
// handle files
//
bool add = true;
if (fileExtensions != null && fileExtensions.Length != 0)
{
add = false;
string s = Path.GetExtension(usn.FileName);
foreach (string extension in fileExtensions)
{
if (0 == string.Compare(s, extension, true))
{
add = true;
break;
}
}
}
if (add)
{
if (!files.ContainsKey(usn.FileReferenceNumber))
{
files.Add(usn.FileReferenceNumber,
new FileNameAndFrn(usn.FileName, usn.ParentFileReferenceNumber));
}
else
{
FileNameAndFrn frn = files[usn.FileReferenceNumber];
if (0 != string.Compare(usn.FileName, frn.Name, true))
{
//Log.InfoFormat(
// "Attempt to add duplicate file reference number: {0} for file {1}, file from index {2}",
// usn.FileReferenceNumber, usn.FileName, frn.Name);
throw new Exception(string.Format("Duplicate FRN: {0} for {1}",
usn.FileReferenceNumber, usn.FileName));
}
}
}
}
pUsnRecord = new IntPtr(pUsnRecord.ToInt32() + usn.RecordLength);
outBytesReturned -= usn.RecordLength;
}
Marshal.WriteInt64(medBuffer, Marshal.ReadInt64(pData, 0));
}
Marshal.FreeHGlobal(pData);
}
