Eindeutiger Vergleich für große Dateien gesucht

[Flocke]

Ich will mal nicht unken, aber 0,20 Sekunden KANN NICHT SEIN, bei keiner Festplatte der Welt!

[Nachtrag]

Modifizier die Routine mal so (rote Stellen), dann bekommst du mit, ob ein Fehler aufgetreten ist (was ich mir denke):

Code:

function CompareFilesMemoryMapped(const File1, File2: String; SysAllocSize: Cardinal): [color=red]integer[/color];
var
  CurSize: DWord;
  CurPos: Int64;
  hFile1, hFile2: THandle;
  hMap1, hMap2: THandle;
  FileSize: Int64;
  P1, P2: Pointer;
begin
  [color=red]Result := -1;[/color]

  hFile1 := CreateFile(@File1[1], GENERIC_READ, FILE_SHARE_READ, nil, OPEN_EXISTING, 0, 0);

  if hFile1 <> INVALID_HANDLE_VALUE then
  try
   hFile2 := CreateFile(@File2[1], GENERIC_READ, FILE_SHARE_READ, nil, OPEN_EXISTING, 0, 0);
   if hFile2 <> INVALID_HANDLE_VALUE then
    try
      FileSize := GetHugeFileSize(File1); //GetFileSizeInt64(hFile1);
      if FileSize = GetHugeFileSize(File2) then //GetFileSizeInt64(hFile1) then
      begin
        Result := True;
        if FileSize > 0 then
        begin
          hMap1 := CreateFileMapping(hFile1, nil, PAGE_READONLY, 0, 0, nil);
          if hMap1 <> INVALID_HANDLE_VALUE then
          try
            hMap2 := CreateFileMapping(hFile2, nil, PAGE_READONLY, 0, 0, nil);
            if hMap2 <> INVALID_HANDLE_VALUE then
            try
              CurSize := FileSize mod SysAllocSize;
              if CurSize = 0 then
               CurSize := SysAllocSize;
              CurPos := FileSize - CurSize;
              repeat
               P1 := MapViewOfFile(hMap1, FILE_MAP_READ, Int64Rec(CurPos).Hi, Int64Rec(CurPos).Lo, CurSize);
                if P1 <> nil then
                try
                 P2 := MapViewOfFile(hMap2, FILE_MAP_READ, Int64Rec(CurPos).Hi, Int64Rec(CurPos).Lo, CurSize);
                 if P2 <> nil then
                  try
                   [color=red]if CompareMem(P1, P2, CurSize)
                     then Result := 1
                     else Result := 0;[/color]
                  finally
                   UnmapViewOfFile(P2);
                  end; // else RaiseLastWin32Error;
                finally
                  UnmapViewOfFile(P1);
                end; // else RaiseLastWin32Error;
                CurPos := CurPos - CurSize;
                CurSize := SysAllocSize;
              until
               (CurPos <= 0) or (not Result);
            finally
             CloseHandle(hMap2);
            end; // else RaiseLastWin32Error;
          finally
           CloseHandle(hMap1);
          end; // else RaiseLastWin32Error;
        end;
      end;
    finally
     CloseHandle(hFile2);
    end; // else RaiseLastWin32Error;
  finally
   CloseHandle(hFile1);
  end; // else RaiseLastWin32Error;
end;