lbcwallet/tx/tx.go
Josh Rickmar b1c246c01b Perform smarter UTXO tracking.
This change fixes many issues with the tracking of unspent transaction
outputs.  First, notifications for when UTXOs arse spent are now
requested from btcd, and when spent, will be removed from the
UtxoStore.

Second, when transactions are created, the unconfirmed (not yet in a
block) Utxo (with block height -1 and zeroed block hash) is added to
the wallet's UtxoStore.  Notifications for when this UTXO is spent are
also requested from btcd.  After the tx appears in a block, because
the UTXO has a pkScript to be spent by another owned wallet address, a
notification with the UTXO will be sent to btcwallet.  We already
store the unconfirmed UTXO, so at this point the actual block height
and hash are filled in.

Finally, when calculating the balance, if confirmations is zero,
unconfirmed UTXOs (block height -1) will be included in the balance.
Otherwise, they are ignored.
2013-10-22 09:55:53 -04:00

640 lines
15 KiB
Go

/*
* Copyright (c) 2013 Conformal Systems LLC <info@conformal.com>
*
* Permission to use, copy, modify, and distribute this software for any
* purpose with or without fee is hereby granted, provided that the above
* copyright notice and this permission notice appear in all copies.
*
* THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
* ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
* ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
* OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
*/
package tx
import (
"bytes"
"code.google.com/p/go.crypto/ripemd160"
"encoding/binary"
"errors"
"fmt"
"github.com/conformal/btcwire"
"io"
)
// Byte headers prepending received and sent serialized transactions.
const (
RecvTxHeader byte = iota
SendTxHeader
)
// UtxoStore is a type used for holding all Utxo structures for all
// addresses in a wallet.
type UtxoStore []*Utxo
// Utxo is a type storing information about a single unspent
// transaction output.
type Utxo struct {
AddrHash [ripemd160.Size]byte
Out OutPoint
Subscript PkScript
Amt uint64 // Measured in Satoshis
// Height is -1 if Utxo has not yet appeared in a block.
Height int64
// BlockHash is zeroed if Utxo has not yet appeared in a block.
BlockHash btcwire.ShaHash
}
// OutPoint is a btcwire.OutPoint with custom methods for serialization.
type OutPoint btcwire.OutPoint
// PkScript is a custom type with methods to serialize pubkey scripts
// of variable length.
type PkScript []byte
// TxStore is a slice holding RecvTx and SendTx pointers.
type TxStore []interface{}
// RecvTx is a type storing information about a transaction that was
// received by an address in a wallet.
type RecvTx struct {
TxHash btcwire.ShaHash
BlockHash btcwire.ShaHash
Height int64
Amt uint64 // Measured in Satoshis
SenderAddr [ripemd160.Size]byte
ReceiverAddr [ripemd160.Size]byte
}
// SendTx is a type storing information about a transaction that was
// sent by an address in a wallet.
type SendTx struct {
TxHash btcwire.ShaHash
BlockHash btcwire.ShaHash
Height int64
Fee uint64 // Measured in Satoshis
SenderAddr [ripemd160.Size]byte
ReceiverAddrs []struct {
Addr [ripemd160.Size]byte
Amt uint64 // Measured in Satoshis
}
}
// We want to use binaryRead and binaryWrite instead of binary.Read
// and binary.Write because those from the binary package do not return
// the number of bytes actually written or read. We need to return
// this value to correctly support the io.ReaderFrom and io.WriterTo
// interfaces.
func binaryRead(r io.Reader, order binary.ByteOrder, data interface{}) (n int64, err error) {
var read int
buf := make([]byte, binary.Size(data))
if read, err = r.Read(buf); err != nil {
return int64(read), err
}
if read < binary.Size(data) {
return int64(read), io.EOF
}
return int64(read), binary.Read(bytes.NewBuffer(buf), order, data)
}
// See comment for binaryRead().
func binaryWrite(w io.Writer, order binary.ByteOrder, data interface{}) (n int64, err error) {
var buf bytes.Buffer
if err = binary.Write(&buf, order, data); err != nil {
return 0, err
}
written, err := w.Write(buf.Bytes())
return int64(written), err
}
// ReadFrom satisifies the io.ReaderFrom interface. Utxo structs are
// read in from r until an io.EOF is reached. If an io.EOF is reached
// before a Utxo is finished being read, err will be non-nil.
func (u *UtxoStore) ReadFrom(r io.Reader) (n int64, err error) {
var read int64
for {
// Read Utxo
utxo := new(Utxo)
read, err = utxo.ReadFrom(r)
if err != nil {
if read == 0 && err == io.EOF {
return n, nil
}
return n + read, err
}
n += read
*u = append(*u, utxo)
}
}
// WriteTo satisifies the io.WriterTo interface. Each Utxo is written
// to w, prepended by a single byte header to distinguish between
// confirmed and unconfirmed outputs.
func (u *UtxoStore) WriteTo(w io.Writer) (n int64, err error) {
var written int64
for _, utxo := range *u {
// Write Utxo
written, err = utxo.WriteTo(w)
if err != nil {
return n + written, err
}
n += written
}
return n, nil
}
// Rollback removes all utxos from and after the block specified
// by a block height and hash.
//
// Correct results rely on u being sorted by block height in
// increasing order.
func (u *UtxoStore) Rollback(height int64, hash *btcwire.ShaHash) (modified bool) {
s := *u
// endlen specifies the final length of the rolled-back UtxoStore.
// Past endlen, array elements are nilled. We do this instead of
// just reslicing with a shorter length to avoid leaving elements
// in the underlying array so they can be garbage collected.
endlen := len(s)
defer func() {
modified = endlen != len(s)
for i := endlen; i < len(s); i++ {
s[i] = nil
}
*u = s[:endlen]
return
}()
for i := len(s) - 1; i >= 0; i-- {
if height > s[i].Height {
break
}
if height == s[i].Height && *hash == s[i].BlockHash {
endlen = i
}
}
return
}
// Remove removes all utxos from toRemove from a UtxoStore. The order
// of utxos in the resulting UtxoStore is unspecified.
func (u *UtxoStore) Remove(toRemove []*Utxo) (modified bool) {
s := *u
m := make(map[*Utxo]bool)
for _, utxo := range s {
m[utxo] = true
}
for _, candidate := range toRemove {
if _, ok := m[candidate]; ok {
modified = true
}
delete(m, candidate)
}
if !modified {
return
}
s = make([]*Utxo, len(m))
i := 0
for utxo := range m {
s[i] = utxo
i++
}
*u = s
return
}
// ReadFrom satisifies the io.ReaderFrom interface. A Utxo is read
// from r with the format:
//
// [AddrHash (20 bytes), Out (36 bytes), Subscript (varies), Amt (8 bytes), Height (8 bytes), BlockHash (32 bytes)]
//
// Each field is read little endian.
func (u *Utxo) ReadFrom(r io.Reader) (n int64, err error) {
datas := []interface{}{
&u.AddrHash,
&u.Out,
&u.Subscript,
&u.Amt,
&u.Height,
&u.BlockHash,
}
var read int64
for _, data := range datas {
if rf, ok := data.(io.ReaderFrom); ok {
read, err = rf.ReadFrom(r)
} else {
read, err = binaryRead(r, binary.LittleEndian, data)
}
if err != nil {
return n + read, err
}
n += read
}
return n, nil
}
// WriteTo satisifies the io.WriterTo interface. A Utxo is written to
// w in the format:
//
// [AddrHash (20 bytes), Out (36 bytes), Subscript (varies), Amt (8 bytes), Height (8 bytes), BlockHash (32 bytes)]
//
// Each field is written little endian.
func (u *Utxo) WriteTo(w io.Writer) (n int64, err error) {
datas := []interface{}{
&u.AddrHash,
&u.Out,
&u.Subscript,
&u.Amt,
&u.Height,
&u.BlockHash,
}
var written int64
for _, data := range datas {
if wt, ok := data.(io.WriterTo); ok {
written, err = wt.WriteTo(w)
} else {
written, err = binaryWrite(w, binary.LittleEndian, data)
}
if err != nil {
return n + written, err
}
n += written
}
return n, nil
}
// ReadFrom satisifies the io.ReaderFrom interface. An OutPoint is read
// from r with the format:
//
// [Hash (32 bytes), Index (4 bytes)]
//
// Each field is read little endian.
func (o *OutPoint) ReadFrom(r io.Reader) (n int64, err error) {
datas := []interface{}{
&o.Hash,
&o.Index,
}
var read int64
for _, data := range datas {
read, err = binaryRead(r, binary.LittleEndian, data)
if err != nil {
return n + read, err
}
n += read
}
return n, nil
}
// WriteTo satisifies the io.WriterTo interface. An OutPoint is written
// to w in the format:
//
// [Hash (32 bytes), Index (4 bytes)]
//
// Each field is written little endian.
func (o *OutPoint) WriteTo(w io.Writer) (n int64, err error) {
datas := []interface{}{
&o.Hash,
&o.Index,
}
var written int64
for _, data := range datas {
written, err = binaryWrite(w, binary.LittleEndian, data)
if err != nil {
return n + written, err
}
n += written
}
return n, nil
}
// ReadFrom satisifies the io.ReaderFrom interface. A PkScript is read
// from r with the format:
//
// [Length (4 byte unsigned integer), ScriptBytes (Length bytes)]
//
// Length is read little endian.
func (s *PkScript) ReadFrom(r io.Reader) (n int64, err error) {
var scriptlen uint32
var read int64
read, err = binaryRead(r, binary.LittleEndian, &scriptlen)
if err != nil {
return n + read, err
}
n += read
scriptbuf := new(bytes.Buffer)
read, err = scriptbuf.ReadFrom(io.LimitReader(r, int64(scriptlen)))
if err != nil {
return n + read, err
}
n += read
*s = scriptbuf.Bytes()
return n, nil
}
// WriteTo satisifies the io.WriterTo interface. A PkScript is written
// to w in the format:
//
// [Length (4 byte unsigned integer), ScriptBytes (Length bytes)]
//
// Length is written little endian.
func (s *PkScript) WriteTo(w io.Writer) (n int64, err error) {
var written int64
written, err = binaryWrite(w, binary.LittleEndian, uint32(len(*s)))
if err != nil {
return n + written, nil
}
n += written
written, err = bytes.NewBuffer(*s).WriteTo(w)
if err != nil {
return n + written, nil
}
n += written
return n, nil
}
// ReadFrom satisifies the io.ReaderFrom interface. A TxStore is read
// in from r with the format:
//
// [[TxHeader (1 byte), Tx (varies in size)]...]
func (txs *TxStore) ReadFrom(r io.Reader) (n int64, err error) {
store := []interface{}{}
defer func() {
*txs = store
}()
var read int64
for {
// Read header
var header byte
read, err = binaryRead(r, binary.LittleEndian, &header)
if err != nil {
// io.EOF is not an error here.
if err == io.EOF {
return n + read, nil
}
return n + read, err
}
n += read
var tx io.ReaderFrom
switch header {
case RecvTxHeader:
tx = new(RecvTx)
case SendTxHeader:
tx = new(SendTx)
default:
return n, fmt.Errorf("unknown Tx header")
}
// Read tx
read, err = tx.ReadFrom(r)
if err != nil {
return n + read, err
}
n += read
store = append(store, tx)
}
}
// WriteTo satisifies the io.WriterTo interface. A TxStore is written
// to w in the format:
//
// [[TxHeader (1 byte), Tx (varies in size)]...]
func (txs *TxStore) WriteTo(w io.Writer) (n int64, err error) {
store := ([]interface{})(*txs)
var written int64
for _, tx := range store {
switch tx.(type) {
case *RecvTx:
written, err = binaryWrite(w, binary.LittleEndian, RecvTxHeader)
if err != nil {
return n + written, err
}
n += written
case *SendTx:
written, err = binaryWrite(w, binary.LittleEndian, SendTxHeader)
if err != nil {
return n + written, err
}
n += written
default:
return n, fmt.Errorf("unknown type in TxStore")
}
wt := tx.(io.WriterTo)
written, err = wt.WriteTo(w)
if err != nil {
return n + written, err
}
n += written
}
return n, nil
}
// Rollback removes all txs from and after the block specified by a
// block height and hash.
//
// Correct results rely on txs being sorted by block height in
// increasing order.
func (txs *TxStore) Rollback(height int64, hash *btcwire.ShaHash) (modified bool) {
s := ([]interface{})(*txs)
// endlen specifies the final length of the rolled-back TxStore.
// Past endlen, array elements are nilled. We do this instead of
// just reslicing with a shorter length to avoid leaving elements
// in the underlying array so they can be garbage collected.
endlen := len(s)
defer func() {
modified = endlen != len(s)
for i := endlen; i < len(s); i++ {
s[i] = nil
}
*txs = s[:endlen]
return
}()
for i := len(s) - 1; i >= 0; i-- {
var txheight int64
var txhash *btcwire.ShaHash
switch s[i].(type) {
case *RecvTx:
tx := s[i].(*RecvTx)
if height > tx.Height {
break
}
txheight = tx.Height
txhash = &tx.BlockHash
case *SendTx:
tx := s[i].(*SendTx)
if height > tx.Height {
break
}
txheight = tx.Height
txhash = &tx.BlockHash
}
if height == txheight && *hash == *txhash {
endlen = i
}
}
return
}
// ReadFrom satisifies the io.ReaderFrom interface. A RecTx is read
// in from r with the format:
//
// [TxHash (32 bytes), BlockHash (32 bytes), Height (8 bytes), Amt (8 bytes), SenderAddr (20 bytes), ReceiverAddr (20 bytes)]
//
// Each field is read little endian.
func (tx *RecvTx) ReadFrom(r io.Reader) (n int64, err error) {
datas := []interface{}{
&tx.TxHash,
&tx.BlockHash,
&tx.Height,
&tx.Amt,
&tx.SenderAddr,
&tx.ReceiverAddr,
}
var read int64
for _, data := range datas {
read, err = binaryRead(r, binary.LittleEndian, data)
if err != nil {
return n + read, err
}
n += read
}
return n, nil
}
// WriteTo satisifies the io.WriterTo interface. A RecvTx is written to
// w in the format:
//
// [TxHash (32 bytes), BlockHash (32 bytes), Height (8 bytes), Amt (8 bytes), SenderAddr (20 bytes), ReceiverAddr (20 bytes)]
//
// Each field is written little endian.
func (tx *RecvTx) WriteTo(w io.Writer) (n int64, err error) {
datas := []interface{}{
&tx.TxHash,
&tx.BlockHash,
&tx.Height,
&tx.Amt,
&tx.SenderAddr,
&tx.ReceiverAddr,
}
var written int64
for _, data := range datas {
written, err = binaryWrite(w, binary.LittleEndian, data)
if err != nil {
return n + written, err
}
n += written
}
return n, nil
}
// ReadFrom satisifies the io.WriterTo interface. A SendTx is read
// from r with the format:
//
// [TxHash (32 bytes), Height (8 bytes), Fee (8 bytes), SenderAddr (20 bytes), len(ReceiverAddrs) (4 bytes), ReceiverAddrs[Addr (20 bytes), Amt (8 bytes)]...]
//
// Each field is read little endian.
func (tx *SendTx) ReadFrom(r io.Reader) (n int64, err error) {
var nReceivers uint32
datas := []interface{}{
&tx.TxHash,
&tx.Height,
&tx.Fee,
&tx.SenderAddr,
&nReceivers,
}
var read int64
for _, data := range datas {
read, err = binaryRead(r, binary.LittleEndian, data)
if err != nil {
return n + read, err
}
n += read
}
if nReceivers == 0 {
// XXX: Is this valid? Entire output is a fee for the miner?
return n, nil
}
tx.ReceiverAddrs = make([]struct {
Addr [ripemd160.Size]byte
Amt uint64
},
nReceivers)
for i := uint32(0); i < nReceivers; i++ {
datas := []interface{}{
&tx.ReceiverAddrs[i].Addr,
&tx.ReceiverAddrs[i].Amt,
}
for _, data := range datas {
read, err = binaryRead(r, binary.LittleEndian, data)
if err != nil {
return n + read, err
}
n += read
}
}
return n, nil
}
// WriteTo satisifies the io.WriterTo interface. A SendTx is written to
// w in the format:
//
// [TxHash (32 bytes), Height (8 bytes), Fee (8 bytes), SenderAddr (20 bytes), len(ReceiverAddrs) (4 bytes), ReceiverAddrs[Addr (20 bytes), Amt (8 bytes)]...]
//
// Each field is written little endian.
func (tx *SendTx) WriteTo(w io.Writer) (n int64, err error) {
nReceivers := uint32(len(tx.ReceiverAddrs))
if int64(nReceivers) != int64(len(tx.ReceiverAddrs)) {
return n, errors.New("too many receiving addresses")
}
datas := []interface{}{
&tx.TxHash,
&tx.Height,
&tx.Fee,
&tx.SenderAddr,
nReceivers,
}
var written int64
for _, data := range datas {
written, err = binaryWrite(w, binary.LittleEndian, data)
if err != nil {
return n + written, err
}
n += written
}
for i := range tx.ReceiverAddrs {
datas := []interface{}{
&tx.ReceiverAddrs[i].Addr,
&tx.ReceiverAddrs[i].Amt,
}
for _, data := range datas {
written, err = binaryWrite(w, binary.LittleEndian, data)
if err != nil {
return n + written, err
}
n += written
}
}
return n, nil
}