package fs import ( "math/rand" "os" "path/filepath" "strconv" "strings" "time" "golang.org/x/sys/windows" ) // fixpath returns an absolute path on windows, so restic can open long file // names. func fixpath(name string) string { abspath, err := filepath.Abs(name) if err == nil { // Check if \\?\UNC\ already exist if strings.HasPrefix(abspath, `\\?\UNC\`) { return abspath } // Check if \\?\ already exist if strings.HasPrefix(abspath, `\\?\`) { return abspath } // Check if path starts with \\ if strings.HasPrefix(abspath, `\\`) { return strings.Replace(abspath, `\\`, `\\?\UNC\`, 1) } // Normal path return `\\?\` + abspath } return name } // TempFile creates a temporary file which is marked as delete-on-close func TempFile(dir, prefix string) (f *os.File, err error) { // slightly modified implementation of os.CreateTemp(dir, prefix) to allow us to add // the FILE_ATTRIBUTE_TEMPORARY | FILE_FLAG_DELETE_ON_CLOSE flags. // These provide two large benefits: // FILE_ATTRIBUTE_TEMPORARY tells Windows to keep the file in memory only if possible // which reduces the amount of unnecessary disk writes. // FILE_FLAG_DELETE_ON_CLOSE instructs Windows to automatically delete the file once // all file descriptors are closed. if dir == "" { dir = os.TempDir() } access := uint32(windows.GENERIC_READ | windows.GENERIC_WRITE) creation := uint32(windows.CREATE_NEW) share := uint32(0) // prevent other processes from accessing the file flags := uint32(windows.FILE_ATTRIBUTE_TEMPORARY | windows.FILE_FLAG_DELETE_ON_CLOSE) rnd := rand.New(rand.NewSource(time.Now().UnixNano())) for i := 0; i < 10000; i++ { randSuffix := strconv.Itoa(int(1e9 + rnd.Intn(1e9)%1e9))[1:] path := filepath.Join(dir, prefix+randSuffix) ptr, err := windows.UTF16PtrFromString(path) if err != nil { return nil, err } h, err := windows.CreateFile(ptr, access, share, nil, creation, flags, 0) if os.IsExist(err) { continue } return os.NewFile(uintptr(h), path), err } // Proper error handling is still to do return nil, os.ErrExist } // Chmod changes the mode of the named file to mode. func Chmod(name string, mode os.FileMode) error { return os.Chmod(fixpath(name), mode) } // ClearSystem removes the system attribute from the file. func ClearSystem(path string) error { return ClearAttribute(path, windows.FILE_ATTRIBUTE_SYSTEM) } // ClearAttribute removes the specified attribute from the file. func ClearAttribute(path string, attribute uint32) error { ptr, err := windows.UTF16PtrFromString(path) if err != nil { return err } fileAttributes, err := windows.GetFileAttributes(ptr) if err != nil { return err } if fileAttributes&attribute != 0 { // Clear the attribute fileAttributes &= ^uint32(attribute) err = windows.SetFileAttributes(ptr, fileAttributes) if err != nil { return err } } return nil }