wire: Define GetCFCheckpt message.

peer/peer.go

@@ -159,6 +159,10 @@ type MessageListeners struct {
 	// bitcoin message.
 	OnGetCFHeaders func(p *Peer, msg *wire.MsgGetCFHeaders)
 
+	// OnGetCFCheckpt is invoked when a peer receives a getcfcheckpt
+	// bitcoin message.
+	OnGetCFCheckpt func(p *Peer, msg *wire.MsgGetCFCheckpt)
+
 	// OnFeeFilter is invoked when a peer receives a feefilter bitcoin message.
 	OnFeeFilter func(p *Peer, msg *wire.MsgFeeFilter)
 
@@ -1601,6 +1605,11 @@ out:
 				p.cfg.Listeners.OnGetCFHeaders(p, msg)
 			}
 
+		case *wire.MsgGetCFCheckpt:
+			if p.cfg.Listeners.OnGetCFCheckpt != nil {
+				p.cfg.Listeners.OnGetCFCheckpt(p, msg)
+			}
+
 		case *wire.MsgCFilter:
 			if p.cfg.Listeners.OnCFilter != nil {
 				p.cfg.Listeners.OnCFilter(p, msg)

peer/peer_test.go

@@ -405,6 +405,9 @@ func TestPeerListeners(t *testing.T) {
 			OnGetCFHeaders: func(p *peer.Peer, msg *wire.MsgGetCFHeaders) {
 				ok <- msg
 			},
+			OnGetCFCheckpt: func(p *peer.Peer, msg *wire.MsgGetCFCheckpt) {
+				ok <- msg
+			},
 			OnCFilter: func(p *peer.Peer, msg *wire.MsgCFilter) {
 				ok <- msg
 			},
@@ -542,6 +545,10 @@ func TestPeerListeners(t *testing.T) {
 			"OnGetCFHeaders",
 			wire.NewMsgGetCFHeaders(wire.GCSFilterRegular, 0, &chainhash.Hash{}),
 		},
+		{
+			"OnGetCFCheckpt",
+			wire.NewMsgGetCFCheckpt(wire.GCSFilterRegular, &chainhash.Hash{}),
+		},
 		{
 			"OnCFilter",
 			wire.NewMsgCFilter(wire.GCSFilterRegular, &chainhash.Hash{},

wire/message.go

@@ -53,6 +53,7 @@ const (
 	CmdFeeFilter    = "feefilter"
 	CmdGetCFilters  = "getcfilters"
 	CmdGetCFHeaders = "getcfheaders"
+	CmdGetCFCheckpt = "getcfcheckpt"
 	CmdCFilter      = "cfilter"
 	CmdCFHeaders    = "cfheaders"
 )
@@ -166,6 +167,9 @@ func makeEmptyMessage(command string) (Message, error) {
 	case CmdGetCFHeaders:
 		msg = &MsgGetCFHeaders{}
 
+	case CmdGetCFCheckpt:
+		msg = &MsgGetCFCheckpt{}
+
 	case CmdCFilter:
 		msg = &MsgCFilter{}
 

wire/message_test.go

@@ -71,6 +71,7 @@ func TestMessage(t *testing.T) {
 	msgReject := NewMsgReject("block", RejectDuplicate, "duplicate block")
 	msgGetCFilters := NewMsgGetCFilters(GCSFilterExtended, 0, &chainhash.Hash{})
 	msgGetCFHeaders := NewMsgGetCFHeaders(GCSFilterExtended, 0, &chainhash.Hash{})
+	msgGetCFCheckpt := NewMsgGetCFCheckpt(GCSFilterExtended, &chainhash.Hash{})
 	msgCFilter := NewMsgCFilter(GCSFilterExtended, &chainhash.Hash{},
 		[]byte("payload"))
 	msgCFHeaders := NewMsgCFHeaders()
@@ -105,6 +106,7 @@ func TestMessage(t *testing.T) {
 		{msgReject, msgReject, pver, MainNet, 79},
 		{msgGetCFilters, msgGetCFilters, pver, MainNet, 61},
 		{msgGetCFHeaders, msgGetCFHeaders, pver, MainNet, 61},
+		{msgGetCFCheckpt, msgGetCFCheckpt, pver, MainNet, 57},
 		{msgCFilter, msgCFilter, pver, MainNet, 65},
 		{msgCFHeaders, msgCFHeaders, pver, MainNet, 90},
 	}

wire/msggetcfcheckpt.go

@@ -0,0 +1,75 @@
+// Copyright (c) 2018 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"
+
+	"github.com/roasbeef/btcd/chaincfg/chainhash"
+)
+
+// MsgGetCFCheckpt is a request for filter headers at evenly spaced intervals
+// throughout the blockchain history. It allows to set the FilterType field to
+// get headers in the chain of basic (0x00) or extended (0x01) headers.
+type MsgGetCFCheckpt struct {
+	FilterType FilterType
+	StopHash   chainhash.Hash
+}
+
+// BtcDecode decodes r using the bitcoin protocol encoding into the receiver.
+// This is part of the Message interface implementation.
+func (msg *MsgGetCFCheckpt) BtcDecode(r io.Reader, pver uint32, _ MessageEncoding) error {
+	err := readElement(r, &msg.FilterType)
+	if err != nil {
+		return err
+	}
+
+	err = readElement(r, &msg.StopHash)
+	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 *MsgGetCFCheckpt) BtcEncode(w io.Writer, pver uint32, _ MessageEncoding) error {
+	err := writeElement(w, msg.FilterType)
+	if err != nil {
+		return err
+	}
+
+	err = writeElement(w, &msg.StopHash)
+	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 *MsgGetCFCheckpt) Command() string {
+	return CmdGetCFCheckpt
+}
+
+// MaxPayloadLength returns the maximum length the payload can be for the
+// receiver.  This is part of the Message interface implementation.
+func (msg *MsgGetCFCheckpt) MaxPayloadLength(pver uint32) uint32 {
+	// Filter type + uint32 + block hash
+	return 1 + chainhash.HashSize
+}
+
+// NewMsgGetCFCheckpt returns a new bitcoin getcfcheckpt message that conforms
+// to the Message interface using the passed parameters and defaults for the
+// remaining fields.
+func NewMsgGetCFCheckpt(filterType FilterType, stopHash *chainhash.Hash,
+) *MsgGetCFCheckpt {
+	return &MsgGetCFCheckpt{
+		FilterType: filterType,
+		StopHash:   *stopHash,
+	}
+}