1// Copyright (c) 2018 The btcsuite developers 2// Use of this source code is governed by an ISC 3// license that can be found in the LICENSE file. 4 5package wire 6 7import ( 8 "io" 9 10 "github.com/btcsuite/btcd/chaincfg/chainhash" 11) 12 13// MsgGetCFCheckpt is a request for filter headers at evenly spaced intervals 14// throughout the blockchain history. It allows to set the FilterType field to 15// get headers in the chain of basic (0x00) or extended (0x01) headers. 16type MsgGetCFCheckpt struct { 17 FilterType FilterType 18 StopHash chainhash.Hash 19} 20 21// BtcDecode decodes r using the bitcoin protocol encoding into the receiver. 22// This is part of the Message interface implementation. 23func (msg *MsgGetCFCheckpt) BtcDecode(r io.Reader, pver uint32, _ MessageEncoding) error { 24 err := readElement(r, &msg.FilterType) 25 if err != nil { 26 return err 27 } 28 29 return readElement(r, &msg.StopHash) 30} 31 32// BtcEncode encodes the receiver to w using the bitcoin protocol encoding. 33// This is part of the Message interface implementation. 34func (msg *MsgGetCFCheckpt) BtcEncode(w io.Writer, pver uint32, _ MessageEncoding) error { 35 err := writeElement(w, msg.FilterType) 36 if err != nil { 37 return err 38 } 39 40 return writeElement(w, &msg.StopHash) 41} 42 43// Command returns the protocol command string for the message. This is part 44// of the Message interface implementation. 45func (msg *MsgGetCFCheckpt) Command() string { 46 return CmdGetCFCheckpt 47} 48 49// MaxPayloadLength returns the maximum length the payload can be for the 50// receiver. This is part of the Message interface implementation. 51func (msg *MsgGetCFCheckpt) MaxPayloadLength(pver uint32) uint32 { 52 // Filter type + uint32 + block hash 53 return 1 + chainhash.HashSize 54} 55 56// NewMsgGetCFCheckpt returns a new bitcoin getcfcheckpt message that conforms 57// to the Message interface using the passed parameters and defaults for the 58// remaining fields. 59func NewMsgGetCFCheckpt(filterType FilterType, stopHash *chainhash.Hash) *MsgGetCFCheckpt { 60 return &MsgGetCFCheckpt{ 61 FilterType: filterType, 62 StopHash: *stopHash, 63 } 64} 65