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

   1 package hotline
   2
   3 import (
   4         "bytes"
   5         "encoding/binary"
   6 )
   7
   8 // FileResumeData is sent when a client or server would like to resume a transfer from an offset
   9 type FileResumeData struct {
  10         Format       [4]byte  // "RFLT"
  11         Version      [2]byte  // Always 1
  12         RSVD         [34]byte // Unused
  13         ForkCount    [2]byte  // Length of ForkInfoList.  Either 2 or 3 depending on whether file has a resource fork
  14         ForkInfoList []ForkInfoList
  15
  16         readOffset int
  17 }
  18
  19 type ForkInfoList struct {
  20         Fork     [4]byte // "DATA" or "MACR"
  21         DataSize [4]byte // offset from which to resume the transfer of data
  22         RSVDA    [4]byte // Unused
  23         RSVDB    [4]byte // Unused
  24 }
  25
  26 func NewForkInfoList(b []byte) *ForkInfoList {
  27         return &ForkInfoList{
  28                 Fork:     [4]byte{0x44, 0x41, 0x54, 0x41},
  29                 DataSize: [4]byte{b[0], b[1], b[2], b[3]},
  30                 RSVDA:    [4]byte{},
  31                 RSVDB:    [4]byte{},
  32         }
  33 }
  34
  35 func NewFileResumeData(list []ForkInfoList) *FileResumeData {
  36         return &FileResumeData{
  37                 Format:       [4]byte{0x52, 0x46, 0x4C, 0x54}, // RFLT
  38                 Version:      [2]byte{0, 1},
  39                 RSVD:         [34]byte{},
  40                 ForkCount:    [2]byte{0, uint8(len(list))},
  41                 ForkInfoList: list,
  42         }
  43 }
  44
  45 //
  46 //func (frd *FileResumeData) Read(p []byte) (int, error) {
  47 //      buf := slices.Concat(
  48 //              frd.Format[:],
  49 //              frd.Version[:],
  50 //              frd.RSVD[:],
  51 //              frd.ForkCount[:],
  52 //      )
  53 //      for _, fil := range frd.ForkInfoList {
  54 //              buf = append(buf, fil...)
  55 //              _ = binary.Write(&buf, binary.LittleEndian, fil)
  56 //      }
  57 //
  58 //      var buf bytes.Buffer
  59 //      _ = binary.Write(&buf, binary.LittleEndian, frd.Format)
  60 //      _ = binary.Write(&buf, binary.LittleEndian, frd.Version)
  61 //      _ = binary.Write(&buf, binary.LittleEndian, frd.RSVD)
  62 //      _ = binary.Write(&buf, binary.LittleEndian, frd.ForkCount)
  63 //      for _, fil := range frd.ForkInfoList {
  64 //              _ = binary.Write(&buf, binary.LittleEndian, fil)
  65 //      }
  66 //
  67 //      return buf.Bytes(), nil
  68 //}
  69
  70 func (frd *FileResumeData) BinaryMarshal() ([]byte, error) {
  71         var buf bytes.Buffer
  72         _ = binary.Write(&buf, binary.LittleEndian, frd.Format)
  73         _ = binary.Write(&buf, binary.LittleEndian, frd.Version)
  74         _ = binary.Write(&buf, binary.LittleEndian, frd.RSVD)
  75         _ = binary.Write(&buf, binary.LittleEndian, frd.ForkCount)
  76         for _, fil := range frd.ForkInfoList {
  77                 _ = binary.Write(&buf, binary.LittleEndian, fil)
  78         }
  79
  80         return buf.Bytes(), nil
  81 }
  82
  83 func (frd *FileResumeData) UnmarshalBinary(b []byte) error {
  84         frd.Format = [4]byte{b[0], b[1], b[2], b[3]}
  85         frd.Version = [2]byte{b[4], b[5]}
  86         frd.ForkCount = [2]byte{b[40], b[41]}
  87
  88         for i := 0; i < int(frd.ForkCount[1]); i++ {
  89                 var fil ForkInfoList
  90                 start := 42 + i*16
  91                 end := start + 16
  92
  93                 r := bytes.NewReader(b[start:end])
  94                 if err := binary.Read(r, binary.BigEndian, &fil); err != nil {
  95                         return err
  96                 }
  97
  98                 frd.ForkInfoList = append(frd.ForkInfoList, fil)
  99         }
 100
 101         return nil
 102 }