| 1 | //go:build windows |
| 2 | |
| 3 | package pathidentity |
| 4 | |
| 5 | import ( |
| 6 | "errors" |
| 7 | "path/filepath" |
| 8 | "strings" |
| 9 | "unsafe" |
| 10 | |
| 11 | "golang.org/x/sys/windows" |
| 12 | ) |
| 13 | |
| 14 | func platformIdentityKey(path string) (string, error) { |
| 15 | return windowsIdentityKeyBy(path, directoryCaseInsensitive) |
| 16 | } |
| 17 | |
| 18 | func windowsIdentityKeyBy(path string, caseForDirectory func(string) (bool, bool, error)) (string, error) { |
| 19 | path = stripExtendedPrefix(path) |
| 20 | volume := filepath.VolumeName(path) |
| 21 | if volume == "" { |
| 22 | return "", errors.New("windows path has no volume") |
| 23 | } |
| 24 | current := volume + string(filepath.Separator) |
| 25 | identity := strings.ToLower(current) |
| 26 | caseInsensitive := true |
| 27 | rest := strings.TrimLeft(path[len(volume):], `\/`) |
| 28 | for _, component := range strings.FieldsFunc(rest, func(r rune) bool { return r == '\\' || r == '/' }) { |
| 29 | insensitive, exists, err := caseForDirectory(current) |
| 30 | if err != nil { |
| 31 | return "", err |
| 32 | } |
| 33 | if exists { |
| 34 | caseInsensitive = insensitive |
| 35 | } |
| 36 | identityComponent := component |
| 37 | if caseInsensitive { |
| 38 | identityComponent = strings.ToLower(component) |
| 39 | } |
| 40 | identity = filepath.Join(identity, identityComponent) |
| 41 | current = filepath.Join(current, component) |
| 42 | } |
| 43 | return filepath.Clean(identity), nil |
| 44 | } |
| 45 | |
| 46 | func directoryCaseInsensitive(path string) (insensitive, exists bool, err error) { |
| 47 | name, err := windows.UTF16PtrFromString(path) |
| 48 | if err != nil { |
| 49 | return false, false, err |
| 50 | } |
| 51 | handle, err := windows.CreateFile(name, windows.FILE_READ_ATTRIBUTES, |
| 52 | windows.FILE_SHARE_READ|windows.FILE_SHARE_WRITE|windows.FILE_SHARE_DELETE, |
| 53 | nil, windows.OPEN_EXISTING, windows.FILE_FLAG_BACKUP_SEMANTICS, 0) |
| 54 | if err != nil { |
| 55 | if errors.Is(err, windows.ERROR_FILE_NOT_FOUND) || errors.Is(err, windows.ERROR_PATH_NOT_FOUND) { |
| 56 | return false, false, nil |
| 57 | } |
| 58 | return false, false, err |
| 59 | } |
| 60 | defer windows.CloseHandle(handle) |
| 61 | var iosb windows.IO_STATUS_BLOCK |
| 62 | var flags uint32 |
| 63 | err = windows.NtQueryInformationFile( |
| 64 | handle, |
| 65 | &iosb, |
| 66 | (*byte)(unsafe.Pointer(&flags)), |
| 67 | uint32(unsafe.Sizeof(flags)), |
| 68 | windows.FileCaseSensitiveInformation, |
| 69 | ) |
| 70 | if caseSensitivityQueryUnsupported(err) { |
| 71 | return true, true, nil |
| 72 | } |
| 73 | if err != nil { |
| 74 | return false, false, err |
| 75 | } |
| 76 | return flags&windows.FILE_CS_FLAG_CASE_SENSITIVE_DIR == 0, true, nil |
| 77 | } |
| 78 | |
| 79 | func caseSensitivityQueryUnsupported(err error) bool { |
| 80 | var status windows.NTStatus |
| 81 | return errors.As(err, &status) && (status == windows.STATUS_INVALID_INFO_CLASS || |
| 82 | status == windows.STATUS_INVALID_PARAMETER || |
| 83 | status == windows.STATUS_NOT_SUPPORTED) |
| 84 | } |
| 85 | |
| 86 | func stripExtendedPrefix(path string) string { |
| 87 | if strings.HasPrefix(strings.ToUpper(path), `\\?\UNC\`) { |
| 88 | return `\\` + path[len(`\\?\UNC\`):] |
| 89 | } |
| 90 | return strings.TrimPrefix(path, `\\?\`) |
| 91 | } |
| 92 |