1// Copyright (c) 2017 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// MsgGetCFHeaders is a message similar to MsgGetHeaders, but for committed 14// filter headers. It allows to set the FilterType field to get headers in the 15// chain of basic (0x00) or extended (0x01) headers. 16type MsgGetCFHeaders struct { 17 FilterType FilterType 18 StartHeight uint32 19 StopHash chainhash.Hash 20} 21 22// BtcDecode decodes r using the bitcoin protocol encoding into the receiver. 23// This is part of the Message interface implementation. 24func (msg *MsgGetCFHeaders) BtcDecode(r io.Reader, pver uint32, _ MessageEncoding) error { 25 err := readElement(r, &msg.FilterType) 26 if err != nil { 27 return err 28 } 29 30 err = readElement(r, &msg.StartHeight) 31 if err != nil { 32 return err 33 } 34 35 return readElement(r, &msg.StopHash) 36} 37 38// BtcEncode encodes the receiver to w using the bitcoin protocol encoding. 39// This is part of the Message interface implementation. 40func (msg *MsgGetCFHeaders) BtcEncode(w io.Writer, pver uint32, _ MessageEncoding) error { 41 err := writeElement(w, msg.FilterType) 42 if err != nil { 43 return err 44 } 45 46 err = writeElement(w, &msg.StartHeight) 47 if err != nil { 48 return err 49 } 50 51 return writeElement(w, &msg.StopHash) 52} 53 54// Command returns the protocol command string for the message. This is part 55// of the Message interface implementation. 56func (msg *MsgGetCFHeaders) Command() string { 57 return CmdGetCFHeaders 58} 59 60// MaxPayloadLength returns the maximum length the payload can be for the 61// receiver. This is part of the Message interface implementation. 62func (msg *MsgGetCFHeaders) MaxPayloadLength(pver uint32) uint32 { 63 // Filter type + uint32 + block hash 64 return 1 + 4 + chainhash.HashSize 65} 66 67// NewMsgGetCFHeaders returns a new bitcoin getcfheader message that conforms to 68// the Message interface using the passed parameters and defaults for the 69// remaining fields. 70func NewMsgGetCFHeaders(filterType FilterType, startHeight uint32, 71 stopHash *chainhash.Hash) *MsgGetCFHeaders { 72 return &MsgGetCFHeaders{ 73 FilterType: filterType, 74 StartHeight: startHeight, 75 StopHash: *stopHash, 76 } 77} 78