48abfdf87c
This commit modifies the existing wire.Message interface to introduce a new MessageEncoding variant which dictates the exact encoding to be used when serializing and deserializing messages. Such an option is now necessary due to the segwit soft-fork package, as btcd will need to be able to optionally encode transactions/blocks without witness data to un-upgraded peers. Two new functions have been introduced: ReadMessageWithEncodingN and WriteMessageWithEncodingN which wrap BtcDecode/BtcEncode with the desired encoding format.
110 lines
3.2 KiB
Go
110 lines
3.2 KiB
Go
// Copyright (c) 2013-2015 The btcsuite developers
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// Use of this source code is governed by an ISC
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// license that can be found in the LICENSE file.
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package wire
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import (
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"fmt"
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"io"
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)
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// MsgNotFound defines a bitcoin notfound message which is sent in response to
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// a getdata message if any of the requested data in not available on the peer.
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// Each message is limited to a maximum number of inventory vectors, which is
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// currently 50,000.
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//
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// Use the AddInvVect function to build up the list of inventory vectors when
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// sending a notfound message to another peer.
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type MsgNotFound struct {
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InvList []*InvVect
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}
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// AddInvVect adds an inventory vector to the message.
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func (msg *MsgNotFound) AddInvVect(iv *InvVect) error {
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if len(msg.InvList)+1 > MaxInvPerMsg {
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str := fmt.Sprintf("too many invvect in message [max %v]",
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MaxInvPerMsg)
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return messageError("MsgNotFound.AddInvVect", str)
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}
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msg.InvList = append(msg.InvList, iv)
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return nil
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}
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// BtcDecode decodes r using the bitcoin protocol encoding into the receiver.
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// This is part of the Message interface implementation.
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func (msg *MsgNotFound) BtcDecode(r io.Reader, pver uint32, enc MessageEncoding) error {
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count, err := ReadVarInt(r, pver)
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if err != nil {
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return err
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}
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// Limit to max inventory vectors per message.
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if count > MaxInvPerMsg {
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str := fmt.Sprintf("too many invvect in message [%v]", count)
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return messageError("MsgNotFound.BtcDecode", str)
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}
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// Create a contiguous slice of inventory vectors to deserialize into in
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// order to reduce the number of allocations.
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invList := make([]InvVect, count)
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msg.InvList = make([]*InvVect, 0, count)
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for i := uint64(0); i < count; i++ {
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iv := &invList[i]
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err := readInvVect(r, pver, iv)
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if err != nil {
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return err
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}
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msg.AddInvVect(iv)
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}
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return nil
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}
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// BtcEncode encodes the receiver to w using the bitcoin protocol encoding.
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// This is part of the Message interface implementation.
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func (msg *MsgNotFound) BtcEncode(w io.Writer, pver uint32, enc MessageEncoding) error {
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// Limit to max inventory vectors per message.
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count := len(msg.InvList)
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if count > MaxInvPerMsg {
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str := fmt.Sprintf("too many invvect in message [%v]", count)
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return messageError("MsgNotFound.BtcEncode", str)
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}
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err := WriteVarInt(w, pver, uint64(count))
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if err != nil {
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return err
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}
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for _, iv := range msg.InvList {
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err := writeInvVect(w, pver, iv)
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if err != nil {
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return err
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}
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}
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return nil
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}
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// Command returns the protocol command string for the message. This is part
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// of the Message interface implementation.
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func (msg *MsgNotFound) Command() string {
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return CmdNotFound
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}
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// MaxPayloadLength returns the maximum length the payload can be for the
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// receiver. This is part of the Message interface implementation.
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func (msg *MsgNotFound) MaxPayloadLength(pver uint32) uint32 {
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// Max var int 9 bytes + max InvVects at 36 bytes each.
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// Num inventory vectors (varInt) + max allowed inventory vectors.
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return MaxVarIntPayload + (MaxInvPerMsg * maxInvVectPayload)
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}
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// NewMsgNotFound returns a new bitcoin notfound message that conforms to the
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// Message interface. See MsgNotFound for details.
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func NewMsgNotFound() *MsgNotFound {
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return &MsgNotFound{
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InvList: make([]*InvVect, 0, defaultInvListAlloc),
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}
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}
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