+++ /dev/null
-// Copyright (c) 2013-2015 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 (
- "fmt"
- "io"
-)
-
-// MsgGetData implements the Message interface and represents a bitcoin
-// getdata message. It is used to request data such as blocks and transactions
-// from another peer. It should be used in response to the inv (MsgInv) message
-// to request the actual data referenced by each inventory vector the receiving
-// peer doesn't already have. Each message is limited to a maximum number of
-// inventory vectors, which is currently 50,000. As a result, multiple messages
-// must be used to request larger amounts of data.
-//
-// Use the AddInvVect function to build up the list of inventory vectors when
-// sending a getdata message to another peer.
-type MsgGetData struct {
- InvList []*InvVect
-}
-
-// AddInvVect adds an inventory vector to the message.
-func (msg *MsgGetData) AddInvVect(iv *InvVect) error {
- if len(msg.InvList)+1 > MaxInvPerMsg {
- str := fmt.Sprintf("too many invvect in message [max %v]",
- MaxInvPerMsg)
- return messageError("MsgGetData.AddInvVect", str)
- }
-
- msg.InvList = append(msg.InvList, iv)
- return nil
-}
-
-// BtcDecode decodes r using the bitcoin protocol encoding into the receiver.
-// This is part of the Message interface implementation.
-func (msg *MsgGetData) BtcDecode(r io.Reader, pver uint32, enc MessageEncoding) error {
- count, err := ReadVarInt(r, pver)
- if err != nil {
- return err
- }
-
- // Limit to max inventory vectors per message.
- if count > MaxInvPerMsg {
- str := fmt.Sprintf("too many invvect in message [%v]", count)
- return messageError("MsgGetData.BtcDecode", str)
- }
-
- // Create a contiguous slice of inventory vectors to deserialize into in
- // order to reduce the number of allocations.
- invList := make([]InvVect, count)
- msg.InvList = make([]*InvVect, 0, count)
- for i := uint64(0); i < count; i++ {
- iv := &invList[i]
- err := readInvVect(r, pver, iv)
- if err != nil {
- return err
- }
- msg.AddInvVect(iv)
- }
-
- return nil
-}
-
-// BtcEncode encodes the receiver to w using the bitcoin protocol encoding.
-// This is part of the Message interface implementation.
-func (msg *MsgGetData) BtcEncode(w io.Writer, pver uint32, enc MessageEncoding) error {
- // Limit to max inventory vectors per message.
- count := len(msg.InvList)
- if count > MaxInvPerMsg {
- str := fmt.Sprintf("too many invvect in message [%v]", count)
- return messageError("MsgGetData.BtcEncode", str)
- }
-
- err := WriteVarInt(w, pver, uint64(count))
- if err != nil {
- return err
- }
-
- for _, iv := range msg.InvList {
- err := writeInvVect(w, pver, iv)
- 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 *MsgGetData) Command() string {
- return CmdGetData
-}
-
-// MaxPayloadLength returns the maximum length the payload can be for the
-// receiver. This is part of the Message interface implementation.
-func (msg *MsgGetData) MaxPayloadLength(pver uint32) uint32 {
- // Num inventory vectors (varInt) + max allowed inventory vectors.
- return MaxVarIntPayload + (MaxInvPerMsg * maxInvVectPayload)
-}
-
-// NewMsgGetData returns a new bitcoin getdata message that conforms to the
-// Message interface. See MsgGetData for details.
-func NewMsgGetData() *MsgGetData {
- return &MsgGetData{
- InvList: make([]*InvVect, 0, defaultInvListAlloc),
- }
-}
-
-// NewMsgGetDataSizeHint returns a new bitcoin getdata message that conforms to
-// the Message interface. See MsgGetData for details. This function differs
-// from NewMsgGetData in that it allows a default allocation size for the
-// backing array which houses the inventory vector list. This allows callers
-// who know in advance how large the inventory list will grow to avoid the
-// overhead of growing the internal backing array several times when appending
-// large amounts of inventory vectors with AddInvVect. Note that the specified
-// hint is just that - a hint that is used for the default allocation size.
-// Adding more (or less) inventory vectors will still work properly. The size
-// hint is limited to MaxInvPerMsg.
-func NewMsgGetDataSizeHint(sizeHint uint) *MsgGetData {
- // Limit the specified hint to the maximum allow per message.
- if sizeHint > MaxInvPerMsg {
- sizeHint = MaxInvPerMsg
- }
-
- return &MsgGetData{
- InvList: make([]*InvVect, 0, sizeHint),
- }
-}
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