2eef3720a9
This commit contains the entire btcwire repository along with several changes needed to move all of the files into the wire directory in order to prepare it for merging. This does NOT update btcd or any of the other packages to use the new location as that will be done separately. - All import paths in the old btcwire test files have been changed to the new location - All references to btcwire as the package name have been chagned to wire - The coveralls badge has been removed since it unfortunately doesn't support coverage of sub-packages This is ongoing work toward #214.
138 lines
4.5 KiB
Go
138 lines
4.5 KiB
Go
// Copyright (c) 2013-2015 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 wire
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import (
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"fmt"
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"io"
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)
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// defaultInvListAlloc is the default size used for the backing array for an
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// inventory list. The array will dynamically grow as needed, but this
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// figure is intended to provide enough space for the max number of inventory
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// vectors in a *typical* inventory message without needing to grow the backing
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// array multiple times. Technically, the list can grow to MaxInvPerMsg, but
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// rather than using that large figure, this figure more accurately reflects the
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// typical case.
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const defaultInvListAlloc = 1000
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// MsgInv implements the Message interface and represents a bitcoin inv message.
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// It is used to advertise a peer's known data such as blocks and transactions
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// through inventory vectors. It may be sent unsolicited to inform other peers
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// of the data or in response to a getblocks message (MsgGetBlocks). Each
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// 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 an inv message to another peer.
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type MsgInv 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 *MsgInv) 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("MsgInv.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 *MsgInv) 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("MsgInv.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 *MsgInv) 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("MsgInv.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 *MsgInv) Command() string {
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return CmdInv
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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 *MsgInv) MaxPayloadLength(pver uint32) uint32 {
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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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// NewMsgInv returns a new bitcoin inv message that conforms to the Message
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// interface. See MsgInv for details.
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func NewMsgInv() *MsgInv {
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return &MsgInv{
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InvList: make([]*InvVect, 0, defaultInvListAlloc),
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}
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}
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// NewMsgInvSizeHint returns a new bitcoin inv message that conforms to the
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// Message interface. See MsgInv for details. This function differs from
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// NewMsgInv in that it allows a default allocation size for the backing array
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// which houses the inventory vector list. This allows callers who know in
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// advance how large the inventory list will grow to avoid the overhead of
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// growing the internal backing array several times when appending large amounts
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// of inventory vectors with AddInvVect. Note that the specified hint is just
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// that - a hint that is used for the default allocation size. Adding more
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// (or less) inventory vectors will still work properly. The size hint is
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// limited to MaxInvPerMsg.
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func NewMsgInvSizeHint(sizeHint uint) *MsgInv {
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// Limit the specified hint to the maximum allow per message.
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if sizeHint > MaxInvPerMsg {
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sizeHint = MaxInvPerMsg
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}
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return &MsgInv{
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InvList: make([]*InvVect, 0, sizeHint),
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}
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}
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