16 MaxLength Integer // TODO: Should this include the length header or not?
19 // io.EOF is returned if the source terminates cleanly on a message boundary.
20 // TODO: Is that before or after the message?
21 func (d *Decoder) Decode(msg *Message) (err error) {
23 err = binary.Read(d.R, binary.BigEndian, &length)
26 err = fmt.Errorf("error reading message length: %s", err)
30 if length > d.MaxLength {
31 return errors.New("message too long")
38 r := &io.LimitedReader{d.R, int64(length)}
39 // Check that all of r was utilized.
45 err = fmt.Errorf("%d bytes unused in message type %d", r.N, msg.Type)
53 msg.Type = MessageType(c)
55 case Choke, Unchoke, Interested, NotInterested, HaveAll, HaveNone:
57 case Have, AllowedFast, Suggest:
58 err = msg.Index.Read(r)
59 case Request, Cancel, Reject:
60 for _, data := range []*Integer{&msg.Index, &msg.Begin, &msg.Length} {
67 b := make([]byte, length-1)
68 _, err = io.ReadFull(r, b)
69 msg.Bitfield = unmarshalBitfield(b)
71 for _, pi := range []*Integer{&msg.Index, &msg.Begin} {
80 //msg.Piece, err = ioutil.ReadAll(r)
81 b := *d.Pool.Get().(*[]byte)
82 n, err := io.ReadFull(r, b)
84 if err != io.ErrUnexpectedEOF || n != int(length-9) {
91 msg.ExtendedID, err = readByte(r)
95 msg.ExtendedPayload, err = ioutil.ReadAll(r)
97 err = binary.Read(r, binary.BigEndian, &msg.Port)
99 err = fmt.Errorf("unknown message type %#v", c)
104 func readByte(r io.Reader) (b byte, err error) {
106 n, err := r.Read(arr[:])
118 func unmarshalBitfield(b []byte) (bf []bool) {
119 for _, c := range b {
120 for i := 7; i >= 0; i-- {
121 bf = append(bf, (c>>uint(i))&1 == 1)