2016-08-18 00:15:58 +00:00
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// Copyright (c) 2013-2016 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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"bytes"
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"fmt"
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"io"
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"strconv"
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"github.com/btcsuite/btcd/chaincfg/chainhash"
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)
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const (
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// TxVersion is the current latest supported transaction version.
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TxVersion = 1
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// MaxTxInSequenceNum is the maximum sequence number the sequence field
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// of a transaction input can be.
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MaxTxInSequenceNum uint32 = 0xffffffff
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// MaxPrevOutIndex is the maximum index the index field of a previous
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// outpoint can be.
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MaxPrevOutIndex uint32 = 0xffffffff
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2018-01-25 13:08:43 +00:00
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// SequenceLockTimeDisabled is a flag that if set on a transaction
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// input's sequence number, the sequence number will not be interpreted
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// as a relative locktime.
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SequenceLockTimeDisabled = 1 << 31
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// SequenceLockTimeIsSeconds is a flag that if set on a transaction
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// input's sequence number, the relative locktime has units of 512
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// seconds.
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SequenceLockTimeIsSeconds = 1 << 22
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// SequenceLockTimeMask is a mask that extracts the relative locktime
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// when masked against the transaction input sequence number.
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SequenceLockTimeMask = 0x0000ffff
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// SequenceLockTimeGranularity is the defined time based granularity
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// for seconds-based relative time locks. When converting from seconds
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// to a sequence number, the value is right shifted by this amount,
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// therefore the granularity of relative time locks in 512 or 2^9
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// seconds. Enforced relative lock times are multiples of 512 seconds.
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SequenceLockTimeGranularity = 9
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// defaultTxInOutAlloc is the default size used for the backing array for
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// transaction inputs and outputs. The array will dynamically grow as needed,
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// but this figure is intended to provide enough space for the number of
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// inputs and outputs in a typical transaction without needing to grow the
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// backing array multiple times.
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2016-08-18 00:15:58 +00:00
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defaultTxInOutAlloc = 15
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// minTxInPayload is the minimum payload size for a transaction input.
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// PreviousOutPoint.Hash + PreviousOutPoint.Index 4 bytes + Varint for
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// SignatureScript length 1 byte + Sequence 4 bytes.
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minTxInPayload = 9 + chainhash.HashSize
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// maxTxInPerMessage is the maximum number of transactions inputs that
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// a transaction which fits into a message could possibly have.
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maxTxInPerMessage = (MaxMessagePayload / minTxInPayload) + 1
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// minTxOutPayload is the minimum payload size for a transaction output.
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// Value 8 bytes + Varint for PkScript length 1 byte.
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minTxOutPayload = 9
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// maxTxOutPerMessage is the maximum number of transactions outputs that
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// a transaction which fits into a message could possibly have.
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maxTxOutPerMessage = (MaxMessagePayload / minTxOutPayload) + 1
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// minTxPayload is the minimum payload size for a transaction. Note
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// that any realistically usable transaction must have at least one
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// input or output, but that is a rule enforced at a higher layer, so
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// it is intentionally not included here.
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// Version 4 bytes + Varint number of transaction inputs 1 byte + Varint
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// number of transaction outputs 1 byte + LockTime 4 bytes + min input
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// payload + min output payload.
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minTxPayload = 10
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// freeListMaxScriptSize is the size of each buffer in the free list
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// that is used for deserializing scripts from the wire before they are
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// concatenated into a single contiguous buffers. This value was chosen
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// because it is slightly more than twice the size of the vast majority
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// of all "standard" scripts. Larger scripts are still deserialized
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// properly as the free list will simply be bypassed for them.
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freeListMaxScriptSize = 512
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// freeListMaxItems is the number of buffers to keep in the free list
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// to use for script deserialization. This value allows up to 100
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// scripts per transaction being simultaneously deserialized by 125
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// peers. Thus, the peak usage of the free list is 12,500 * 512 =
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// 6,400,000 bytes.
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freeListMaxItems = 12500
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)
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// scriptFreeList defines a free list of byte slices (up to the maximum number
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// defined by the freeListMaxItems constant) that have a cap according to the
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// freeListMaxScriptSize constant. It is used to provide temporary buffers for
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// deserializing scripts in order to greatly reduce the number of allocations
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// required.
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//
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// The caller can obtain a buffer from the free list by calling the Borrow
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// function and should return it via the Return function when done using it.
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type scriptFreeList chan []byte
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// Borrow returns a byte slice from the free list with a length according the
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// provided size. A new buffer is allocated if there are any items available.
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//
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// When the size is larger than the max size allowed for items on the free list
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// a new buffer of the appropriate size is allocated and returned. It is safe
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// to attempt to return said buffer via the Return function as it will be
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// ignored and allowed to go the garbage collector.
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func (c scriptFreeList) Borrow(size uint64) []byte {
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if size > freeListMaxScriptSize {
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return make([]byte, size, size)
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}
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var buf []byte
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select {
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case buf = <-c:
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default:
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buf = make([]byte, freeListMaxScriptSize)
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}
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return buf[:size]
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}
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// Return puts the provided byte slice back on the free list when it has a cap
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// of the expected length. The buffer is expected to have been obtained via
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// the Borrow function. Any slices that are not of the appropriate size, such
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// as those whose size is greater than the largest allowed free list item size
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// are simply ignored so they can go to the garbage collector.
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func (c scriptFreeList) Return(buf []byte) {
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// Ignore any buffers returned that aren't the expected size for the
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// free list.
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if cap(buf) != freeListMaxScriptSize {
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return
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}
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// Return the buffer to the free list when it's not full. Otherwise let
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// it be garbage collected.
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select {
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case c <- buf:
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default:
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// Let it go to the garbage collector.
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}
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}
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// Create the concurrent safe free list to use for script deserialization. As
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// previously described, this free list is maintained to significantly reduce
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// the number of allocations.
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var scriptPool scriptFreeList = make(chan []byte, freeListMaxItems)
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// OutPoint defines a bitcoin data type that is used to track previous
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// transaction outputs.
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type OutPoint struct {
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Hash chainhash.Hash
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Index uint32
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}
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// NewOutPoint returns a new bitcoin transaction outpoint point with the
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// provided hash and index.
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func NewOutPoint(hash *chainhash.Hash, index uint32) *OutPoint {
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return &OutPoint{
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Hash: *hash,
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Index: index,
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}
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}
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// String returns the OutPoint in the human-readable form "hash:index".
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func (o OutPoint) String() string {
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// Allocate enough for hash string, colon, and 10 digits. Although
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// at the time of writing, the number of digits can be no greater than
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// the length of the decimal representation of maxTxOutPerMessage, the
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// maximum message payload may increase in the future and this
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// optimization may go unnoticed, so allocate space for 10 decimal
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// digits, which will fit any uint32.
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buf := make([]byte, 2*chainhash.HashSize+1, 2*chainhash.HashSize+1+10)
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copy(buf, o.Hash.String())
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buf[2*chainhash.HashSize] = ':'
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buf = strconv.AppendUint(buf, uint64(o.Index), 10)
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return string(buf)
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}
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// TxIn defines a bitcoin transaction input.
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type TxIn struct {
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PreviousOutPoint OutPoint
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SignatureScript []byte
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Sequence uint32
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}
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// SerializeSize returns the number of bytes it would take to serialize the
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// the transaction input.
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func (t *TxIn) SerializeSize() int {
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// Outpoint Hash 32 bytes + Outpoint Index 4 bytes + Sequence 4 bytes +
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// serialized varint size for the length of SignatureScript +
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// SignatureScript bytes.
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return 40 + VarIntSerializeSize(uint64(len(t.SignatureScript))) +
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len(t.SignatureScript)
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}
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// NewTxIn returns a new bitcoin transaction input with the provided
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// previous outpoint point and signature script with a default sequence of
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// MaxTxInSequenceNum.
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func NewTxIn(prevOut *OutPoint, signatureScript []byte) *TxIn {
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return &TxIn{
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PreviousOutPoint: *prevOut,
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SignatureScript: signatureScript,
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Sequence: MaxTxInSequenceNum,
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}
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}
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// TxOut defines a bitcoin transaction output.
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type TxOut struct {
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Value int64
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PkScript []byte
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}
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// SerializeSize returns the number of bytes it would take to serialize the
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// the transaction output.
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func (t *TxOut) SerializeSize() int {
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// Value 8 bytes + serialized varint size for the length of PkScript +
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// PkScript bytes.
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return 8 + VarIntSerializeSize(uint64(len(t.PkScript))) + len(t.PkScript)
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}
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// NewTxOut returns a new bitcoin transaction output with the provided
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// transaction value and public key script.
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func NewTxOut(value int64, pkScript []byte) *TxOut {
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return &TxOut{
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Value: value,
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PkScript: pkScript,
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}
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}
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// MsgTx implements the Message interface and represents a bitcoin tx message.
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// It is used to deliver transaction information in response to a getdata
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// message (MsgGetData) for a given transaction.
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//
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// Use the AddTxIn and AddTxOut functions to build up the list of transaction
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// inputs and outputs.
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type MsgTx struct {
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Version int32
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TxIn []*TxIn
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TxOut []*TxOut
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LockTime uint32
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}
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// AddTxIn adds a transaction input to the message.
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func (msg *MsgTx) AddTxIn(ti *TxIn) {
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msg.TxIn = append(msg.TxIn, ti)
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}
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// AddTxOut adds a transaction output to the message.
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func (msg *MsgTx) AddTxOut(to *TxOut) {
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msg.TxOut = append(msg.TxOut, to)
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}
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// TxHash generates the Hash for the transaction.
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func (msg *MsgTx) TxHash() chainhash.Hash {
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// Encode the transaction and calculate double sha256 on the result.
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// Ignore the error returns since the only way the encode could fail
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// is being out of memory or due to nil pointers, both of which would
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// cause a run-time panic.
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buf := bytes.NewBuffer(make([]byte, 0, msg.SerializeSize()))
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_ = msg.Serialize(buf)
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return chainhash.DoubleHashH(buf.Bytes())
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}
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// Copy creates a deep copy of a transaction so that the original does not get
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// modified when the copy is manipulated.
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func (msg *MsgTx) Copy() *MsgTx {
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// Create new tx and start by copying primitive values and making space
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// for the transaction inputs and outputs.
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newTx := MsgTx{
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Version: msg.Version,
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TxIn: make([]*TxIn, 0, len(msg.TxIn)),
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TxOut: make([]*TxOut, 0, len(msg.TxOut)),
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LockTime: msg.LockTime,
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}
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// Deep copy the old TxIn data.
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for _, oldTxIn := range msg.TxIn {
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// Deep copy the old previous outpoint.
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oldOutPoint := oldTxIn.PreviousOutPoint
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newOutPoint := OutPoint{}
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newOutPoint.Hash.SetBytes(oldOutPoint.Hash[:])
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newOutPoint.Index = oldOutPoint.Index
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// Deep copy the old signature script.
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var newScript []byte
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oldScript := oldTxIn.SignatureScript
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oldScriptLen := len(oldScript)
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if oldScriptLen > 0 {
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newScript = make([]byte, oldScriptLen, oldScriptLen)
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copy(newScript, oldScript[:oldScriptLen])
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}
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// Create new txIn with the deep copied data and append it to
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// new Tx.
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newTxIn := TxIn{
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PreviousOutPoint: newOutPoint,
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SignatureScript: newScript,
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Sequence: oldTxIn.Sequence,
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}
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newTx.TxIn = append(newTx.TxIn, &newTxIn)
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}
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// Deep copy the old TxOut data.
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for _, oldTxOut := range msg.TxOut {
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// Deep copy the old PkScript
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var newScript []byte
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oldScript := oldTxOut.PkScript
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oldScriptLen := len(oldScript)
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if oldScriptLen > 0 {
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newScript = make([]byte, oldScriptLen, oldScriptLen)
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copy(newScript, oldScript[:oldScriptLen])
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}
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// Create new txOut with the deep copied data and append it to
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// new Tx.
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newTxOut := TxOut{
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Value: oldTxOut.Value,
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PkScript: newScript,
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}
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newTx.TxOut = append(newTx.TxOut, &newTxOut)
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}
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return &newTx
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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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// See Deserialize for decoding transactions stored to disk, such as in a
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// database, as opposed to decoding transactions from the wire.
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func (msg *MsgTx) BtcDecode(r io.Reader, pver uint32) error {
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version, err := binarySerializer.Uint32(r, littleEndian)
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if err != nil {
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return err
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}
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msg.Version = int32(version)
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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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// Prevent more input transactions than could possibly fit into a
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// message. It would be possible to cause memory exhaustion and panics
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// without a sane upper bound on this count.
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if count > uint64(maxTxInPerMessage) {
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str := fmt.Sprintf("too many input transactions to fit into "+
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"max message size [count %d, max %d]", count,
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maxTxInPerMessage)
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return messageError("MsgTx.BtcDecode", str)
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}
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// returnScriptBuffers is a closure that returns any script buffers that
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// were borrowed from the pool when there are any deserialization
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// errors. This is only valid to call before the final step which
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// replaces the scripts with the location in a contiguous buffer and
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// returns them.
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returnScriptBuffers := func() {
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for _, txIn := range msg.TxIn {
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if txIn == nil || txIn.SignatureScript == nil {
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|
continue
|
|
|
|
}
|
|
|
|
scriptPool.Return(txIn.SignatureScript)
|
|
|
|
}
|
|
|
|
for _, txOut := range msg.TxOut {
|
|
|
|
if txOut == nil || txOut.PkScript == nil {
|
|
|
|
continue
|
|
|
|
}
|
|
|
|
scriptPool.Return(txOut.PkScript)
|
|
|
|
}
|
|
|
|
}
|
|
|
|
|
|
|
|
// Deserialize the inputs.
|
|
|
|
var totalScriptSize uint64
|
|
|
|
txIns := make([]TxIn, count)
|
|
|
|
msg.TxIn = make([]*TxIn, count)
|
|
|
|
for i := uint64(0); i < count; i++ {
|
|
|
|
// The pointer is set now in case a script buffer is borrowed
|
|
|
|
// and needs to be returned to the pool on error.
|
|
|
|
ti := &txIns[i]
|
|
|
|
msg.TxIn[i] = ti
|
|
|
|
err = readTxIn(r, pver, msg.Version, ti)
|
|
|
|
if err != nil {
|
|
|
|
returnScriptBuffers()
|
|
|
|
return err
|
|
|
|
}
|
|
|
|
totalScriptSize += uint64(len(ti.SignatureScript))
|
|
|
|
}
|
|
|
|
|
|
|
|
count, err = ReadVarInt(r, pver)
|
|
|
|
if err != nil {
|
|
|
|
returnScriptBuffers()
|
|
|
|
return err
|
|
|
|
}
|
|
|
|
|
|
|
|
// Prevent more output transactions than could possibly fit into a
|
|
|
|
// message. It would be possible to cause memory exhaustion and panics
|
|
|
|
// without a sane upper bound on this count.
|
|
|
|
if count > uint64(maxTxOutPerMessage) {
|
|
|
|
returnScriptBuffers()
|
|
|
|
str := fmt.Sprintf("too many output transactions to fit into "+
|
|
|
|
"max message size [count %d, max %d]", count,
|
|
|
|
maxTxOutPerMessage)
|
|
|
|
return messageError("MsgTx.BtcDecode", str)
|
|
|
|
}
|
|
|
|
|
|
|
|
// Deserialize the outputs.
|
|
|
|
txOuts := make([]TxOut, count)
|
|
|
|
msg.TxOut = make([]*TxOut, count)
|
|
|
|
for i := uint64(0); i < count; i++ {
|
|
|
|
// The pointer is set now in case a script buffer is borrowed
|
|
|
|
// and needs to be returned to the pool on error.
|
|
|
|
to := &txOuts[i]
|
|
|
|
msg.TxOut[i] = to
|
|
|
|
err = readTxOut(r, pver, msg.Version, to)
|
|
|
|
if err != nil {
|
|
|
|
returnScriptBuffers()
|
|
|
|
return err
|
|
|
|
}
|
|
|
|
totalScriptSize += uint64(len(to.PkScript))
|
|
|
|
}
|
|
|
|
|
|
|
|
msg.LockTime, err = binarySerializer.Uint32(r, littleEndian)
|
|
|
|
if err != nil {
|
|
|
|
returnScriptBuffers()
|
|
|
|
return err
|
|
|
|
}
|
|
|
|
|
|
|
|
// Create a single allocation to house all of the scripts and set each
|
|
|
|
// input signature script and output public key script to the
|
|
|
|
// appropriate subslice of the overall contiguous buffer. Then, return
|
|
|
|
// each individual script buffer back to the pool so they can be reused
|
|
|
|
// for future deserializations. This is done because it significantly
|
|
|
|
// reduces the number of allocations the garbage collector needs to
|
|
|
|
// track, which in turn improves performance and drastically reduces the
|
|
|
|
// amount of runtime overhead that would otherwise be needed to keep
|
|
|
|
// track of millions of small allocations.
|
|
|
|
//
|
|
|
|
// NOTE: It is no longer valid to call the returnScriptBuffers closure
|
|
|
|
// after these blocks of code run because it is already done and the
|
|
|
|
// scripts in the transaction inputs and outputs no longer point to the
|
|
|
|
// buffers.
|
|
|
|
var offset uint64
|
|
|
|
scripts := make([]byte, totalScriptSize)
|
|
|
|
for i := 0; i < len(msg.TxIn); i++ {
|
|
|
|
// Copy the signature script into the contiguous buffer at the
|
|
|
|
// appropriate offset.
|
|
|
|
signatureScript := msg.TxIn[i].SignatureScript
|
|
|
|
copy(scripts[offset:], signatureScript)
|
|
|
|
|
|
|
|
// Reset the signature script of the transaction input to the
|
|
|
|
// slice of the contiguous buffer where the script lives.
|
|
|
|
scriptSize := uint64(len(signatureScript))
|
|
|
|
end := offset + scriptSize
|
|
|
|
msg.TxIn[i].SignatureScript = scripts[offset:end:end]
|
|
|
|
offset += scriptSize
|
|
|
|
|
|
|
|
// Return the temporary script buffer to the pool.
|
|
|
|
scriptPool.Return(signatureScript)
|
|
|
|
}
|
|
|
|
for i := 0; i < len(msg.TxOut); i++ {
|
|
|
|
// Copy the public key script into the contiguous buffer at the
|
|
|
|
// appropriate offset.
|
|
|
|
pkScript := msg.TxOut[i].PkScript
|
|
|
|
copy(scripts[offset:], pkScript)
|
|
|
|
|
|
|
|
// Reset the public key script of the transaction output to the
|
|
|
|
// slice of the contiguous buffer where the script lives.
|
|
|
|
scriptSize := uint64(len(pkScript))
|
|
|
|
end := offset + scriptSize
|
|
|
|
msg.TxOut[i].PkScript = scripts[offset:end:end]
|
|
|
|
offset += scriptSize
|
|
|
|
|
|
|
|
// Return the temporary script buffer to the pool.
|
|
|
|
scriptPool.Return(pkScript)
|
|
|
|
}
|
|
|
|
|
|
|
|
return nil
|
|
|
|
}
|
|
|
|
|
|
|
|
// Deserialize decodes a transaction from r into the receiver using a format
|
|
|
|
// that is suitable for long-term storage such as a database while respecting
|
|
|
|
// the Version field in the transaction. This function differs from BtcDecode
|
|
|
|
// in that BtcDecode decodes from the bitcoin wire protocol as it was sent
|
|
|
|
// across the network. The wire encoding can technically differ depending on
|
|
|
|
// the protocol version and doesn't even really need to match the format of a
|
|
|
|
// stored transaction at all. As of the time this comment was written, the
|
|
|
|
// encoded transaction is the same in both instances, but there is a distinct
|
|
|
|
// difference and separating the two allows the API to be flexible enough to
|
|
|
|
// deal with changes.
|
|
|
|
func (msg *MsgTx) Deserialize(r io.Reader) error {
|
|
|
|
// At the current time, there is no difference between the wire encoding
|
|
|
|
// at protocol version 0 and the stable long-term storage format. As
|
|
|
|
// a result, make use of BtcDecode.
|
|
|
|
return msg.BtcDecode(r, 0)
|
|
|
|
}
|
|
|
|
|
|
|
|
// BtcEncode encodes the receiver to w using the bitcoin protocol encoding.
|
|
|
|
// This is part of the Message interface implementation.
|
|
|
|
// See Serialize for encoding transactions to be stored to disk, such as in a
|
|
|
|
// database, as opposed to encoding transactions for the wire.
|
|
|
|
func (msg *MsgTx) BtcEncode(w io.Writer, pver uint32) error {
|
|
|
|
err := binarySerializer.PutUint32(w, littleEndian, uint32(msg.Version))
|
|
|
|
if err != nil {
|
|
|
|
return err
|
|
|
|
}
|
|
|
|
|
|
|
|
count := uint64(len(msg.TxIn))
|
|
|
|
err = WriteVarInt(w, pver, count)
|
|
|
|
if err != nil {
|
|
|
|
return err
|
|
|
|
}
|
|
|
|
|
|
|
|
for _, ti := range msg.TxIn {
|
|
|
|
err = writeTxIn(w, pver, msg.Version, ti)
|
|
|
|
if err != nil {
|
|
|
|
return err
|
|
|
|
}
|
|
|
|
}
|
|
|
|
|
|
|
|
count = uint64(len(msg.TxOut))
|
|
|
|
err = WriteVarInt(w, pver, count)
|
|
|
|
if err != nil {
|
|
|
|
return err
|
|
|
|
}
|
|
|
|
|
|
|
|
for _, to := range msg.TxOut {
|
|
|
|
err = writeTxOut(w, pver, msg.Version, to)
|
|
|
|
if err != nil {
|
|
|
|
return err
|
|
|
|
}
|
|
|
|
}
|
|
|
|
|
2018-01-25 13:08:43 +00:00
|
|
|
return binarySerializer.PutUint32(w, littleEndian, msg.LockTime)
|
2016-08-18 00:15:58 +00:00
|
|
|
}
|
|
|
|
|
|
|
|
// Serialize encodes the transaction to w using a format that suitable for
|
|
|
|
// long-term storage such as a database while respecting the Version field in
|
|
|
|
// the transaction. This function differs from BtcEncode in that BtcEncode
|
|
|
|
// encodes the transaction to the bitcoin wire protocol in order to be sent
|
|
|
|
// across the network. The wire encoding can technically differ depending on
|
|
|
|
// the protocol version and doesn't even really need to match the format of a
|
|
|
|
// stored transaction at all. As of the time this comment was written, the
|
|
|
|
// encoded transaction is the same in both instances, but there is a distinct
|
|
|
|
// difference and separating the two allows the API to be flexible enough to
|
|
|
|
// deal with changes.
|
|
|
|
func (msg *MsgTx) Serialize(w io.Writer) error {
|
|
|
|
// At the current time, there is no difference between the wire encoding
|
|
|
|
// at protocol version 0 and the stable long-term storage format. As
|
|
|
|
// a result, make use of BtcEncode.
|
|
|
|
return msg.BtcEncode(w, 0)
|
|
|
|
|
|
|
|
}
|
|
|
|
|
|
|
|
// SerializeSize returns the number of bytes it would take to serialize the
|
|
|
|
// the transaction.
|
|
|
|
func (msg *MsgTx) SerializeSize() int {
|
|
|
|
// Version 4 bytes + LockTime 4 bytes + Serialized varint size for the
|
|
|
|
// number of transaction inputs and outputs.
|
|
|
|
n := 8 + VarIntSerializeSize(uint64(len(msg.TxIn))) +
|
|
|
|
VarIntSerializeSize(uint64(len(msg.TxOut)))
|
|
|
|
|
|
|
|
for _, txIn := range msg.TxIn {
|
|
|
|
n += txIn.SerializeSize()
|
|
|
|
}
|
|
|
|
|
|
|
|
for _, txOut := range msg.TxOut {
|
|
|
|
n += txOut.SerializeSize()
|
|
|
|
}
|
|
|
|
|
|
|
|
return n
|
|
|
|
}
|
|
|
|
|
|
|
|
// Command returns the protocol command string for the message. This is part
|
|
|
|
// of the Message interface implementation.
|
|
|
|
func (msg *MsgTx) Command() string {
|
|
|
|
return CmdTx
|
|
|
|
}
|
|
|
|
|
|
|
|
// MaxPayloadLength returns the maximum length the payload can be for the
|
|
|
|
// receiver. This is part of the Message interface implementation.
|
|
|
|
func (msg *MsgTx) MaxPayloadLength(pver uint32) uint32 {
|
|
|
|
return MaxBlockPayload
|
|
|
|
}
|
|
|
|
|
|
|
|
// PkScriptLocs returns a slice containing the start of each public key script
|
|
|
|
// within the raw serialized transaction. The caller can easily obtain the
|
|
|
|
// length of each script by using len on the script available via the
|
|
|
|
// appropriate transaction output entry.
|
|
|
|
func (msg *MsgTx) PkScriptLocs() []int {
|
|
|
|
numTxOut := len(msg.TxOut)
|
|
|
|
if numTxOut == 0 {
|
|
|
|
return nil
|
|
|
|
}
|
|
|
|
|
|
|
|
// The starting offset in the serialized transaction of the first
|
|
|
|
// transaction output is:
|
|
|
|
//
|
|
|
|
// Version 4 bytes + serialized varint size for the number of
|
|
|
|
// transaction inputs and outputs + serialized size of each transaction
|
|
|
|
// input.
|
|
|
|
n := 4 + VarIntSerializeSize(uint64(len(msg.TxIn))) +
|
|
|
|
VarIntSerializeSize(uint64(numTxOut))
|
|
|
|
for _, txIn := range msg.TxIn {
|
|
|
|
n += txIn.SerializeSize()
|
|
|
|
}
|
|
|
|
|
|
|
|
// Calculate and set the appropriate offset for each public key script.
|
|
|
|
pkScriptLocs := make([]int, numTxOut)
|
|
|
|
for i, txOut := range msg.TxOut {
|
|
|
|
// The offset of the script in the transaction output is:
|
|
|
|
//
|
|
|
|
// Value 8 bytes + serialized varint size for the length of
|
|
|
|
// PkScript.
|
|
|
|
n += 8 + VarIntSerializeSize(uint64(len(txOut.PkScript)))
|
|
|
|
pkScriptLocs[i] = n
|
|
|
|
n += len(txOut.PkScript)
|
|
|
|
}
|
|
|
|
|
|
|
|
return pkScriptLocs
|
|
|
|
}
|
|
|
|
|
|
|
|
// NewMsgTx returns a new bitcoin tx message that conforms to the Message
|
|
|
|
// interface. The return instance has a default version of TxVersion and there
|
|
|
|
// are no transaction inputs or outputs. Also, the lock time is set to zero
|
|
|
|
// to indicate the transaction is valid immediately as opposed to some time in
|
|
|
|
// future.
|
2018-01-25 13:08:43 +00:00
|
|
|
func NewMsgTx(version int32) *MsgTx {
|
2016-08-18 00:15:58 +00:00
|
|
|
return &MsgTx{
|
2018-01-25 13:08:43 +00:00
|
|
|
Version: version,
|
2016-08-18 00:15:58 +00:00
|
|
|
TxIn: make([]*TxIn, 0, defaultTxInOutAlloc),
|
|
|
|
TxOut: make([]*TxOut, 0, defaultTxInOutAlloc),
|
|
|
|
}
|
|
|
|
}
|
|
|
|
|
|
|
|
// readOutPoint reads the next sequence of bytes from r as an OutPoint.
|
|
|
|
func readOutPoint(r io.Reader, pver uint32, version int32, op *OutPoint) error {
|
|
|
|
_, err := io.ReadFull(r, op.Hash[:])
|
|
|
|
if err != nil {
|
|
|
|
return err
|
|
|
|
}
|
|
|
|
|
|
|
|
op.Index, err = binarySerializer.Uint32(r, littleEndian)
|
2018-01-25 13:08:43 +00:00
|
|
|
return err
|
2016-08-18 00:15:58 +00:00
|
|
|
}
|
|
|
|
|
|
|
|
// writeOutPoint encodes op to the bitcoin protocol encoding for an OutPoint
|
|
|
|
// to w.
|
|
|
|
func writeOutPoint(w io.Writer, pver uint32, version int32, op *OutPoint) error {
|
|
|
|
_, err := w.Write(op.Hash[:])
|
|
|
|
if err != nil {
|
|
|
|
return err
|
|
|
|
}
|
|
|
|
|
2018-01-25 13:08:43 +00:00
|
|
|
return binarySerializer.PutUint32(w, littleEndian, op.Index)
|
2016-08-18 00:15:58 +00:00
|
|
|
}
|
|
|
|
|
|
|
|
// readScript reads a variable length byte array that represents a transaction
|
|
|
|
// script. It is encoded as a varInt containing the length of the array
|
|
|
|
// followed by the bytes themselves. An error is returned if the length is
|
|
|
|
// greater than the passed maxAllowed parameter which helps protect against
|
|
|
|
// memory exhuastion attacks and forced panics thorugh malformed messages. The
|
|
|
|
// fieldName parameter is only used for the error message so it provides more
|
|
|
|
// context in the error.
|
|
|
|
func readScript(r io.Reader, pver uint32, maxAllowed uint32, fieldName string) ([]byte, error) {
|
|
|
|
count, err := ReadVarInt(r, pver)
|
|
|
|
if err != nil {
|
|
|
|
return nil, err
|
|
|
|
}
|
|
|
|
|
|
|
|
// Prevent byte array larger than the max message size. It would
|
|
|
|
// be possible to cause memory exhaustion and panics without a sane
|
|
|
|
// upper bound on this count.
|
|
|
|
if count > uint64(maxAllowed) {
|
|
|
|
str := fmt.Sprintf("%s is larger than the max allowed size "+
|
|
|
|
"[count %d, max %d]", fieldName, count, maxAllowed)
|
|
|
|
return nil, messageError("readScript", str)
|
|
|
|
}
|
|
|
|
|
|
|
|
b := scriptPool.Borrow(count)
|
|
|
|
_, err = io.ReadFull(r, b)
|
|
|
|
if err != nil {
|
|
|
|
scriptPool.Return(b)
|
|
|
|
return nil, err
|
|
|
|
}
|
|
|
|
return b, nil
|
|
|
|
}
|
|
|
|
|
|
|
|
// readTxIn reads the next sequence of bytes from r as a transaction input
|
|
|
|
// (TxIn).
|
|
|
|
func readTxIn(r io.Reader, pver uint32, version int32, ti *TxIn) error {
|
|
|
|
err := readOutPoint(r, pver, version, &ti.PreviousOutPoint)
|
|
|
|
if err != nil {
|
|
|
|
return err
|
|
|
|
}
|
|
|
|
|
|
|
|
ti.SignatureScript, err = readScript(r, pver, MaxMessagePayload,
|
|
|
|
"transaction input signature script")
|
|
|
|
if err != nil {
|
|
|
|
return err
|
|
|
|
}
|
|
|
|
|
2018-01-25 13:08:43 +00:00
|
|
|
return readElement(r, &ti.Sequence)
|
2016-08-18 00:15:58 +00:00
|
|
|
}
|
|
|
|
|
|
|
|
// writeTxIn encodes ti to the bitcoin protocol encoding for a transaction
|
|
|
|
// input (TxIn) to w.
|
|
|
|
func writeTxIn(w io.Writer, pver uint32, version int32, ti *TxIn) error {
|
|
|
|
err := writeOutPoint(w, pver, version, &ti.PreviousOutPoint)
|
|
|
|
if err != nil {
|
|
|
|
return err
|
|
|
|
}
|
|
|
|
|
|
|
|
err = WriteVarBytes(w, pver, ti.SignatureScript)
|
|
|
|
if err != nil {
|
|
|
|
return err
|
|
|
|
}
|
|
|
|
|
2018-01-25 13:08:43 +00:00
|
|
|
return binarySerializer.PutUint32(w, littleEndian, ti.Sequence)
|
2016-08-18 00:15:58 +00:00
|
|
|
}
|
|
|
|
|
|
|
|
// readTxOut reads the next sequence of bytes from r as a transaction output
|
|
|
|
// (TxOut).
|
|
|
|
func readTxOut(r io.Reader, pver uint32, version int32, to *TxOut) error {
|
|
|
|
err := readElement(r, &to.Value)
|
|
|
|
if err != nil {
|
|
|
|
return err
|
|
|
|
}
|
|
|
|
|
|
|
|
to.PkScript, err = readScript(r, pver, MaxMessagePayload,
|
|
|
|
"transaction output public key script")
|
2018-01-25 13:08:43 +00:00
|
|
|
return err
|
2016-08-18 00:15:58 +00:00
|
|
|
}
|
|
|
|
|
|
|
|
// writeTxOut encodes to into the bitcoin protocol encoding for a transaction
|
|
|
|
// output (TxOut) to w.
|
|
|
|
func writeTxOut(w io.Writer, pver uint32, version int32, to *TxOut) error {
|
|
|
|
err := binarySerializer.PutUint64(w, littleEndian, uint64(to.Value))
|
|
|
|
if err != nil {
|
|
|
|
return err
|
|
|
|
}
|
|
|
|
|
2018-01-25 13:08:43 +00:00
|
|
|
return WriteVarBytes(w, pver, to.PkScript)
|
2016-08-18 00:15:58 +00:00
|
|
|
}
|