git.r.bdr.sh - rbdr/mobius/blob - hotline/file_path.go

   1 package hotline
   2
   3 import (
   4         "bytes"
   5         "encoding/binary"
   6         "errors"
   7         "path"
   8 )
   9
  10 const pathSeparator = "/" // File path separator TODO: make configurable to support Windows
  11
  12 // FilePathItem represents the file or directory portion of a delimited file path (e.g. foo and bar in "/foo/bar")
  13 // 00 00
  14 // 09
  15 // 73 75 62 66 6f 6c 64 65 72 // "subfolder"
  16 type FilePathItem struct {
  17         Len  byte
  18         Name []byte
  19 }
  20
  21 func NewFilePathItem(b []byte) FilePathItem {
  22         return FilePathItem{
  23                 Len:  b[2],
  24                 Name: b[3:],
  25         }
  26 }
  27
  28 type FilePath struct {
  29         ItemCount [2]byte
  30         Items     []FilePathItem
  31 }
  32
  33 const minFilePathLen = 2
  34 func (fp *FilePath) UnmarshalBinary(b []byte) error {
  35         if b == nil {
  36                 return nil
  37         }
  38         if len(b) < minFilePathLen {
  39                 return errors.New("insufficient bytes")
  40         }
  41         err := binary.Read(bytes.NewReader(b[0:2]), binary.BigEndian, &fp.ItemCount)
  42         if err != nil {
  43                 return err
  44         }
  45
  46         pathData := b[2:]
  47         for i := uint16(0); i < fp.Len(); i++ {
  48                 segLen := pathData[2]
  49                 fp.Items = append(fp.Items, NewFilePathItem(pathData[:segLen+3]))
  50                 pathData = pathData[3+segLen:]
  51         }
  52
  53         return nil
  54 }
  55
  56 func (fp *FilePath) Len() uint16 {
  57         return binary.BigEndian.Uint16(fp.ItemCount[:])
  58 }
  59
  60 func (fp *FilePath) String() string {
  61         out := []string{"/"}
  62         for _, i := range fp.Items {
  63                 out = append(out, string(i.Name))
  64         }
  65
  66         return path.Join(out...)
  67 }
  68
  69 func ReadFilePath(filePathFieldData []byte) string {
  70         var fp FilePath
  71         err := fp.UnmarshalBinary(filePathFieldData)
  72         if err != nil {
  73                 // TODO
  74         }
  75         return fp.String()
  76 }
  77
  78 func readPath(fileRoot string, filePath, fileName []byte) (fullPath string, err error) {
  79         var fp FilePath
  80         if filePath != nil {
  81                 if err = fp.UnmarshalBinary(filePath); err != nil {
  82                         return "", err
  83                 }
  84         }
  85
  86         fullPath = path.Join(
  87                 "/",
  88                 fileRoot,
  89                 fp.String(),
  90                 path.Join("/", string(fileName)),
  91         )
  92
  93         return fullPath, nil
  94 }