/
File Transfer.go
49 lines (41 loc) · 1.37 KB
/
File Transfer.go
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/*
File Username: File Transfer.go
Copyright: 2021 Peernet s.r.o.
Author: Peter Kleissner
Encoding of file transfer protocol. Each transfer starts with a header:
Offset Size Info
0 8 Total File Size
8 8 Transfer Size
*/
package protocol
import (
"encoding/binary"
"errors"
"io"
)
// FileTransferWriteHeader starts writing the header for a file transfer.
func FileTransferWriteHeader(writer io.Writer, fileSize, transferSize uint64) (err error) {
// Send the header: Total File Size and Transfer Size.
header := make([]byte, 16)
binary.LittleEndian.PutUint64(header[0:8], fileSize)
binary.LittleEndian.PutUint64(header[8:16], transferSize)
if n, err := writer.Write(header); err != nil {
return err
} else if n != len(header) {
return errors.New("error sending header")
}
return nil
}
// FileTransferReadHeader starts reading the header for a file transfer. It will only read the header and keeps the connection open.
func FileTransferReadHeader(reader io.Reader) (fileSize, transferSize uint64, err error) {
// read the header
header := make([]byte, 16)
if n, err := reader.Read(header); err != nil {
return 0, 0, err
} else if n != len(header) {
return 0, 0, errors.New("error reading header")
}
fileSize = binary.LittleEndian.Uint64(header[0:8])
transferSize = binary.LittleEndian.Uint64(header[8:16])
return fileSize, transferSize, nil
}