status-go/vendor/github.com/btcsuite/btcd/wire/msgping.go

88 lines
2.6 KiB
Go

// Copyright (c) 2013-2015 The btcsuite developers
// Use of this source code is governed by an ISC
// license that can be found in the LICENSE file.
package wire
import (
"io"
)
// MsgPing implements the Message interface and represents a bitcoin ping
// message.
//
// For versions BIP0031Version and earlier, it is used primarily to confirm
// that a connection is still valid. A transmission error is typically
// interpreted as a closed connection and that the peer should be removed.
// For versions AFTER BIP0031Version it contains an identifier which can be
// returned in the pong message to determine network timing.
//
// The payload for this message just consists of a nonce used for identifying
// it later.
type MsgPing struct {
// Unique value associated with message that is used to identify
// specific ping message.
Nonce uint64
}
// BtcDecode decodes r using the bitcoin protocol encoding into the receiver.
// This is part of the Message interface implementation.
func (msg *MsgPing) BtcDecode(r io.Reader, pver uint32, enc MessageEncoding) error {
// There was no nonce for BIP0031Version and earlier.
// NOTE: > is not a mistake here. The BIP0031 was defined as AFTER
// the version unlike most others.
if pver > BIP0031Version {
err := readElement(r, &msg.Nonce)
if err != nil {
return err
}
}
return nil
}
// BtcEncode encodes the receiver to w using the bitcoin protocol encoding.
// This is part of the Message interface implementation.
func (msg *MsgPing) BtcEncode(w io.Writer, pver uint32, enc MessageEncoding) error {
// There was no nonce for BIP0031Version and earlier.
// NOTE: > is not a mistake here. The BIP0031 was defined as AFTER
// the version unlike most others.
if pver > BIP0031Version {
err := writeElement(w, msg.Nonce)
if err != nil {
return err
}
}
return nil
}
// Command returns the protocol command string for the message. This is part
// of the Message interface implementation.
func (msg *MsgPing) Command() string {
return CmdPing
}
// MaxPayloadLength returns the maximum length the payload can be for the
// receiver. This is part of the Message interface implementation.
func (msg *MsgPing) MaxPayloadLength(pver uint32) uint32 {
plen := uint32(0)
// There was no nonce for BIP0031Version and earlier.
// NOTE: > is not a mistake here. The BIP0031 was defined as AFTER
// the version unlike most others.
if pver > BIP0031Version {
// Nonce 8 bytes.
plen += 8
}
return plen
}
// NewMsgPing returns a new bitcoin ping message that conforms to the Message
// interface. See MsgPing for details.
func NewMsgPing(nonce uint64) *MsgPing {
return &MsgPing{
Nonce: nonce,
}
}