本文只针对NTFS格式化的磁盘文件快速检索，速度不是非常快，是让你震惊。
一般用文件遍历的方法检索一个50G的文件夹需要几十分钟甚至一个小时的时间，而用本方法只需几秒。
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using
System;using
System.Collections.Generic;using
System.Linq;using
System.Text;using
System.Runtime.InteropServices;using
Microsoft.VisualBasic;public
class MFTScanner{ private
static IntPtr INVALID_HANDLE_VALUE = new
IntPtr(-1); private
const uint GENERIC_READ = 0x80000000; private
const int FILE_SHARE_READ = 0x1; private
const int FILE_SHARE_WRITE = 0x2; private
const int OPEN_EXISTING = 3; private
const int FILE_READ_ATTRIBUTES = 0x80; private
const int FILE_NAME_IINFORMATION = 9; private
const int FILE_FLAG_BACKUP_SEMANTICS = 0x2000000; private
const int FILE_OPEN_FOR_BACKUP_INTENT = 0x4000; private
const int FILE_OPEN_BY_FILE_ID = 0x2000; private
const int FILE_OPEN = 0x1; private
const int OBJ_CASE_INSENSITIVE = 0x40; private
const int FSCTL_ENUM_USN_DATA = 0x900b3; [StructLayout(LayoutKind.Sequential)] private
struct MFT_ENUM_DATA { public
long StartFileReferenceNumber; public
long LowUsn; public
long HighUsn; } [StructLayout(LayoutKind.Sequential)] private
struct USN_RECORD { public
int RecordLength; public
short MajorVersion; public
short MinorVersion; public
long FileReferenceNumber; public
long ParentFileReferenceNumber; public
long Usn; public
long TimeStamp; public
int Reason; public
int SourceInfo; public
int SecurityId; public
FileAttribute FileAttributes; public
short FileNameLength; public
short FileNameOffset; } [StructLayout(LayoutKind.Sequential)] private
struct IO_STATUS_BLOCK { public
int Status; public
int Information; } [StructLayout(LayoutKind.Sequential)] private
struct UNICODE_STRING { public
short Length; public
short MaximumLength; public
IntPtr Buffer; } [StructLayout(LayoutKind.Sequential)] private
struct OBJECT_ATTRIBUTES { public
int Length; public
IntPtr RootDirectory; public
IntPtr ObjectName; public
int Attributes; public
int SecurityDescriptor; public
int SecurityQualityOfService; } //// MFT_ENUM_DATA [DllImport("kernel32.dll", ExactSpelling = true, SetLastError = true, CharSet = CharSet.Auto)] private
static extern bool DeviceIoControl(IntPtr hDevice, int
dwIoControlCode, ref
MFT_ENUM_DATA lpInBuffer, int
nInBufferSize, IntPtr lpOutBuffer, int
nOutBufferSize, ref
int lpBytesReturned, IntPtr lpOverlapped); [DllImport("kernel32.dll", SetLastError = true, CharSet = CharSet.Auto)] private
static extern IntPtr CreateFile(string
lpFileName, uint
dwDesiredAccess, int
dwShareMode, IntPtr lpSecurityAttributes, int
dwCreationDisposition, int
dwFlagsAndAttributes, IntPtr hTemplateFile); [DllImport("kernel32.dll", ExactSpelling = true, SetLastError = true, CharSet = CharSet.Auto)] private
static extern Int32 CloseHandle(IntPtr lpObject); [DllImport("ntdll.dll", ExactSpelling = true, SetLastError = true, CharSet = CharSet.Auto)] private
static extern int NtCreateFile(ref
IntPtr FileHandle, int
DesiredAccess, ref
OBJECT_ATTRIBUTES ObjectAttributes, ref
IO_STATUS_BLOCK IoStatusBlock, int
AllocationSize, int
FileAttribs, int
SharedAccess, int
CreationDisposition, int
CreateOptions, int
EaBuffer, int
EaLength); [DllImport("ntdll.dll", ExactSpelling = true, SetLastError = true, CharSet = CharSet.Auto)] private
static extern int NtQueryInformationFile(IntPtr FileHandle, ref
IO_STATUS_BLOCK IoStatusBlock, IntPtr FileInformation, int
Length, int
FileInformationClass); private
IntPtr m_hCJ; private
IntPtr m_Buffer; private
int m_BufferSize; private
string m_DriveLetter; private
class FSNode { public
long FRN; public
long ParentFRN; public
string FileName; public
bool IsFile; public
FSNode(long
lFRN, long
lParentFSN, string
sFileName, bool
bIsFile) { FRN = lFRN; ParentFRN = lParentFSN; FileName = sFileName; IsFile = bIsFile; } } private
IntPtr OpenVolume(string
szDriveLetter) { IntPtr hCJ = default(IntPtr); //// volume handle m_DriveLetter = szDriveLetter; hCJ = CreateFile("\\\\.\\"
+ szDriveLetter, GENERIC_READ, FILE_SHARE_READ | FILE_SHARE_WRITE, IntPtr.Zero, OPEN_EXISTING, 0, IntPtr.Zero); return
hCJ; } private
void Cleanup() { if
(m_hCJ != IntPtr.Zero) { // Close the volume handle. CloseHandle(m_hCJ); m_hCJ = INVALID_HANDLE_VALUE; } if
(m_Buffer != IntPtr.Zero) { // Free the allocated memory Marshal.FreeHGlobal(m_Buffer); m_Buffer = IntPtr.Zero; } } public
IEnumerable<String> EnumerateFiles(string
szDriveLetter) { try { var
usnRecord = default(USN_RECORD); var
mft = default(MFT_ENUM_DATA); var
dwRetBytes = 0; var
cb = 0; var
dicFRNLookup = new
Dictionary<long, FSNode>(); var
bIsFile = false; // This shouldn‘t be called more than once. if
(m_Buffer.ToInt32() != 0) { throw
new Exception("invalid buffer"); } // 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(‘\\‘); // Open the volume handle m_hCJ = OpenVolume(szDriveLetter); // Check if the volume handle is valid. if
(m_hCJ == INVALID_HANDLE_VALUE) { throw
new Exception("Couldn‘t open handle to the volume."); } mft.StartFileReferenceNumber = 0; mft.LowUsn = 0; mft.HighUsn = long.MaxValue; do { if
(DeviceIoControl(m_hCJ, FSCTL_ENUM_USN_DATA, ref
mft, Marshal.SizeOf(mft), m_Buffer, m_BufferSize, ref
dwRetBytes, IntPtr.Zero)) { cb = dwRetBytes; // Pointer to the first record IntPtr pUsnRecord = new
IntPtr(m_Buffer.ToInt32() + 8); while
((dwRetBytes > 8)) { // Copy pointer to USN_RECORD structure. usnRecord = (USN_RECORD)Marshal.PtrToStructure(pUsnRecord, usnRecord.GetType()); // The filename within the USN_RECORD. string
FileName = Marshal.PtrToStringUni(new
IntPtr(pUsnRecord.ToInt32() + usnRecord.FileNameOffset), usnRecord.FileNameLength / 2); bIsFile = !usnRecord.FileAttributes.HasFlag(FileAttribute.Directory); dicFRNLookup.Add(usnRecord.FileReferenceNumber, new
FSNode(usnRecord.FileReferenceNumber, usnRecord.ParentFileReferenceNumber, FileName, bIsFile)); // Pointer to the next record in the buffer. pUsnRecord = new
IntPtr(pUsnRecord.ToInt32() + usnRecord.RecordLength); dwRetBytes -= usnRecord.RecordLength; } // The first 8 bytes is always the start of the next USN. mft.StartFileReferenceNumber = Marshal.ReadInt64(m_Buffer, 0); } else { break; // TODO: might not be correct. Was : Exit Do } } while
(!(cb <= 8)); // Resolve all paths for Files foreach
(FSNode oFSNode in
dicFRNLookup.Values.Where(o => o.IsFile)) { string
sFullPath = oFSNode.FileName; FSNode oParentFSNode = oFSNode; while
(dicFRNLookup.TryGetValue(oParentFSNode.ParentFRN, out
oParentFSNode)) { sFullPath = string.Concat(oParentFSNode.FileName, "\\", sFullPath); } sFullPath = string.Concat(szDriveLetter, "\\", sFullPath); yield
return sFullPath; } } finally { //// cleanup Cleanup(); } }} |
调用方法：
using
System;using
System.Collections.Generic;using
System.Linq;using
System.Text;using
System.IO;using
System.Diagnostics;namespace
ConsoleApplication28{ class
Program { static
void Main(string[] args) { var
sw = Stopwatch.StartNew(); var
files = EnumerateFiles("f:").ToArray(); var
elapsed = sw.ElapsedMilliseconds.ToString(); Console.WriteLine(string.Format("Found {0} files, elapsed {1} ms", files.Length, elapsed)); } }} |
方法只能传磁盘名
原文：http://www.cnblogs.com/tuyile006/p/3578856.html