1 package wire
2 3 import (
4 "fmt"
5 "io"
6 )
7 8 // MsgSendHeaders implements the Message interface and represents a bitcoin sendheaders message. It is used to request
9 // the peer send block headers rather than inventory vectors. This message has no payload and was not added until
10 // protocol versions starting with SendHeadersVersion.
11 type MsgSendHeaders struct{}
12 13 // BtcDecode decodes r using the bitcoin protocol encoding into the receiver. This is part of the Message interface
14 // implementation.
15 func (msg *MsgSendHeaders) BtcDecode(r io.Reader, pver uint32, enc MessageEncoding) (e error) {
16 if pver < SendHeadersVersion {
17 str := fmt.Sprintf("sendheaders message invalid for protocol "+
18 "version %d", pver,
19 )
20 return messageError("MsgSendHeaders.BtcDecode", str)
21 }
22 return nil
23 }
24 25 // BtcEncode encodes the receiver to w using the bitcoin protocol encoding. This is part of the Message interface
26 // implementation.
27 func (msg *MsgSendHeaders) BtcEncode(w io.Writer, pver uint32, enc MessageEncoding) (e error) {
28 if pver < SendHeadersVersion {
29 str := fmt.Sprintf("sendheaders message invalid for protocol "+
30 "version %d", pver,
31 )
32 return messageError("MsgSendHeaders.BtcEncode", str)
33 }
34 return nil
35 }
36 37 // Command returns the protocol command string for the message. This is part of the Message interface implementation.
38 func (msg *MsgSendHeaders) Command() string {
39 return CmdSendHeaders
40 }
41 42 // MaxPayloadLength returns the maximum length the payload can be for the receiver. This is part of the Message
43 // interface implementation.
44 func (msg *MsgSendHeaders) MaxPayloadLength(pver uint32) uint32 {
45 return 0
46 }
47 48 // NewMsgSendHeaders returns a new bitcoin sendheaders message that conforms to the Message interface. See
49 // MsgSendHeaders for details.
50 func NewMsgSendHeaders() *MsgSendHeaders {
51 return &MsgSendHeaders{}
52 }
53