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

   1 package hotline
   2
   3 import (
   4         "bytes"
   5         "encoding/binary"
   6         "errors"
   7         "fmt"
   8         "io"
   9 )
  10
  11 type transfer struct {
  12         Protocol        [4]byte // "HTXF" 0x48545846
  13         ReferenceNumber [4]byte // Unique Type generated for the transfer
  14         DataSize        [4]byte // File size
  15         RSVD            [4]byte // Not implemented in Hotline Protocol
  16 }
  17
  18 var HTXF = [4]byte{0x48, 0x54, 0x58, 0x46} // (HTXF) is the only supported transfer protocol
  19
  20 func (tf *transfer) Write(b []byte) (int, error) {
  21         if err := binary.Read(bytes.NewReader(b), binary.BigEndian, tf); err != nil {
  22                 return 0, err
  23         }
  24
  25         if tf.Protocol != HTXF {
  26                 return 0, errors.New("invalid protocol")
  27         }
  28
  29         return len(b), nil
  30 }
  31
  32 func receiveFile(r io.Reader, targetFile, resForkFile, infoFork, counterWriter io.Writer) error {
  33         var ffo flattenedFileObject
  34         if _, err := ffo.ReadFrom(r); err != nil {
  35                 return fmt.Errorf("read flatted file object: %v", err)
  36         }
  37
  38         // Write the information fork
  39         _, err := io.Copy(infoFork, &ffo.FlatFileInformationFork)
  40         if err != nil {
  41                 return fmt.Errorf("write the information fork: %v", err)
  42         }
  43
  44         if _, err = io.CopyN(targetFile, io.TeeReader(r, counterWriter), ffo.dataSize()); err != nil {
  45                 return fmt.Errorf("copy file data to partial file: %v", err)
  46         }
  47
  48         if ffo.FlatFileHeader.ForkCount == [2]byte{0, 3} {
  49                 if err := binary.Read(r, binary.BigEndian, &ffo.FlatFileResForkHeader); err != nil {
  50                         return fmt.Errorf("read resource fork header: %v", err)
  51                 }
  52
  53                 if _, err = io.CopyN(resForkFile, io.TeeReader(r, counterWriter), ffo.rsrcSize()); err != nil {
  54                         return fmt.Errorf("read resource fork: %v", err)
  55                 }
  56         }
  57         return nil
  58 }