/// <summary>
/// This function queries the usn journal on the volume.
/// </summary>
/// <param name="usnJournalState">the USN_JOURNAL_DATA object that is associated with this volume</param>
/// <returns>
/// The success state of the <c>WinApi32.DeviceIoControl</c> call.
/// </returns>
private bool QueryUsnJournal(ref Win32Api.USN_JOURNAL_DATA usnJournalState)
{
UInt32 cb;
return(Win32Api.DeviceIoControl(
_usnJournalRootHandle,
Win32Api.FSCTL_QUERY_USN_JOURNAL,
IntPtr.Zero,
0,
out usnJournalState,
Marshal.SizeOf(usnJournalState),
out cb,
IntPtr.Zero
));
}
/// <summary>
/// GetFileAndDirEntries() reads the Master File Table to find all of the files and
/// folders on a volume and returns them individually.
/// </summary>
/// <param name="dirs">The directories.</param>
/// <param name="files">The files.</param>
/// <param name="filter">The filter.</param>
private void GetFileAndDirEntries(out ConcurrentDictionary <ulong, Win32Api.UsnEntry> dirs, out ConcurrentBag <Win32Api.UsnEntry> files, Regex filter = null)
{
dirs = new ConcurrentDictionary <ulong, Win32Api.UsnEntry>();
files = new ConcurrentBag <Win32Api.UsnEntry>();
var usnState = new Win32Api.USN_JOURNAL_DATA();
if (!QueryUsnJournal(ref usnState))
{
throw new Win32Exception("Failed to query the USN journal on the volume.");
}
//
// set up MFT_ENUM_DATA structure
//
Win32Api.MFT_ENUM_DATA med;
med.StartFileReferenceNumber = 0;
med.LowUsn = 0;
med.HighUsn = usnState.NextUsn;
Int32 sizeMftEnumData = Marshal.SizeOf(med);
IntPtr medBuffer = Marshal.AllocHGlobal(sizeMftEnumData);
Win32Api.ZeroMemory(medBuffer, sizeMftEnumData);
Marshal.StructureToPtr(med, medBuffer, true);
//
// set up the data buffer which receives the USN_RECORD data
//
int pDataSize = sizeof(UInt64) + 10000;
IntPtr pData = Marshal.AllocHGlobal(pDataSize);
Win32Api.ZeroMemory(pData, pDataSize);
uint outBytesReturned = 0;
//
// Gather up volume's directories
//
while (Win32Api.DeviceIoControl(
_usnJournalRootHandle,
Win32Api.FSCTL_ENUM_USN_DATA,
medBuffer,
sizeMftEnumData,
pData,
pDataSize,
out outBytesReturned,
IntPtr.Zero))
{
IntPtr pUsnRecord = new IntPtr((Utils.Is64Bit ? pData.ToInt64() : pData.ToInt32()) + sizeof(Int64));
while (outBytesReturned > 60)
{
var usnEntry = new Win32Api.UsnEntry(pUsnRecord);
if (usnEntry.IsFile && (filter == null || filter.IsMatch(usnEntry.Name)))
{
files.Add(usnEntry);
}
if (usnEntry.IsFolder)
{
dirs.TryAdd(usnEntry.FileReferenceNumber, usnEntry);
}
pUsnRecord = new IntPtr((Utils.Is64Bit ? pUsnRecord.ToInt64() : pUsnRecord.ToInt32()) + usnEntry.RecordLength);
outBytesReturned -= usnEntry.RecordLength;
}
Marshal.WriteInt64(medBuffer, Marshal.ReadInt64(pData, 0));
}
Marshal.FreeHGlobal(pData);
}
