4deb922c9d
Although it is possible to get the command name for each msg type by creating an instances of the type and calling the Command method against it, it's slightly more efficient to simply allows callers to have direct access to the exported constants. This is currently really useful for the reject message since callers need to be able to examine the command type to determine whether or not the hash field needs to be included.
108 lines
3 KiB
Go
108 lines
3 KiB
Go
// Copyright (c) 2013-2014 Conformal Systems LLC.
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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 btcwire
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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) 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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msg.InvList = make([]*InvVect, 0, count)
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for i := uint64(0); i < count; i++ {
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iv := InvVect{}
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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) 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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