מצאתי פרוייקט ממש מוצלח, שבו תוך 3-4 שניות מקבלים רשימה של כל הקבצים והתקיות שיש בכונן C מה שע''י פונקציות רגילות של Directory.GetDirectories או Directory.GetFiles יכול לקחת כמה דקות ארוכות.
אבל הבעיה היא שהוא תמיד סורק את כל הכונן, וזה לא מתאים כאשר הכונן גדול ואני צריך לסרוק רק איזו תקיה קטנה.
השאלה יש למישהו הצעה איך ליעל את הדברים האלו למקסימום? אולי למישהו יש רעיון לשפץ את הפונקציה המהירה שלא תסרוק את הכל אלא רק את מה שצריך?
תודה לכולם ושבת שלום.
Public Sub FindAllFiles(ByVal szDriveLetter As String,
fFileFound As FileFound_Delegate,
fProgress As Progress_Delegate,
fMatch As IsMatch_Delegate)
Dim usnRecord As USN_RECORD
Dim mft As MFT_ENUM_DATA
Dim dwRetBytes As Integer
Dim cb As Integer
Dim dicFRNLookup As New Dictionary(Of Long, FSNode)
Dim bIsFile As Boolean
' This shouldn't be called more than once.
If m_Buffer.ToInt32 <> 0 Then
Console.WriteLine("invalid buffer")
Exit Sub
End If
' progress
If Not IsNothing(fProgress) Then fProgress.Invoke("Building file list.")
' Assign buffer size
m_BufferSize = 65536 '64KB
' Allocate a buffer to use for reading records.
m_Buffer = Marshal.AllocHGlobal(m_BufferSize)
' correct path
szDriveLetter = szDriveLetter.TrimEnd("\"c)
' Open the volume handle
m_hCJ = OpenVolume(szDriveLetter)
' Check if the volume handle is valid.
If m_hCJ = INVALID_HANDLE_VALUE Then
Console.WriteLine("Couldn't open handle to the volume.")
Cleanup()
Exit Sub
End If
mft.StartFileReferenceNumber = 0
mft.LowUsn = 0
mft.HighUsn = Long.MaxValue
Do
If DeviceIoControl(m_hCJ, FSCTL_ENUM_USN_DATA, mft, Marshal.SizeOf(mft), m_Buffer, m_BufferSize, dwRetBytes, IntPtr.Zero) Then
cb = dwRetBytes
' Pointer to the first record
Dim pUsnRecord As New IntPtr(m_Buffer.ToInt32() + 8)
While (dwRetBytes > 8)
' Copy pointer to USN_RECORD structure.
usnRecord = Marshal.PtrToStructure(pUsnRecord, usnRecord.GetType)
' The filename within the USN_RECORD.
Dim FileName As String = Marshal.PtrToStringUni(New IntPtr(pUsnRecord.ToInt32() + usnRecord.FileNameOffset), usnRecord.FileNameLength / 2)
'If Not FileName.StartsWith("$") Then
' use a delegate to determine if this file even matches our criteria
Dim bIsMatch As Boolean = True
If Not IsNothing(fMatch) Then fMatch.Invoke(FileName, usnRecord.FileAttributes, bIsMatch)
If bIsMatch Then
bIsFile = Not usnRecord.FileAttributes.HasFlag(FileAttribute.Directory)
dicFRNLookup.Add(usnRecord.FileReferenceNumber, New FSNode(usnRecord.FileReferenceNumber, usnRecord.ParentFileReferenceNumber, FileName, bIsFile))
End If
'End If
' Pointer to the next record in the buffer.
pUsnRecord = New IntPtr(pUsnRecord.ToInt32() + usnRecord.RecordLength)
dwRetBytes -= usnRecord.RecordLength
End While
' The first 8 bytes is always the start of the next USN.
mft.StartFileReferenceNumber = Marshal.ReadInt64(m_Buffer, 0)
Else
Exit Do
End If
Loop Until cb <= 8
If Not IsNothing(fProgress) Then fProgress.Invoke("Parsing file names.")
' Resolve all paths for Files
For Each oFSNode As FSNode In dicFRNLookup.Values.Where(Function(o) o.IsFile)
Dim sFullPath As String = oFSNode.FileName
Dim oParentFSNode As FSNode = oFSNode
While dicFRNLookup.TryGetValue(oParentFSNode.ParentFRN, oParentFSNode)
sFullPath = String.Concat(oParentFSNode.FileName, "\", sFullPath)
End While
sFullPath = String.Concat(szDriveLetter, "\", sFullPath)
If Not IsNothing(fFileFound) Then fFileFound.Invoke(sFullPath, 0)
Next
'// cleanup
Cleanup()
If Not IsNothing(fProgress) Then fProgress.Invoke("Complete.")
End Sub
פורסם במקור בפורום CODE613 ב11/10/2013 10:51 (+03:00)
