lnd.xprv/uspv/txstore.go

120 lines
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2016-01-15 06:56:25 +03:00
package uspv
import (
"bytes"
"fmt"
"log"
"github.com/btcsuite/btcd/wire"
"github.com/btcsuite/btcutil"
"github.com/btcsuite/btcutil/bloom"
)
type TxStore struct {
KnownTxids []wire.ShaHash
Utxos []Utxo // stacks on stacks
Sum int64 // racks on racks
Adrs []MyAdr // endeavouring to acquire capital
}
type Utxo struct { // cash money.
// combo of outpoint and txout which has all the info needed to spend
Op wire.OutPoint
Txo wire.TxOut
KeyIdx uint32 // index for private key needed to sign / spend
}
type MyAdr struct { // an address I have the private key for
btcutil.Address
KeyIdx uint32 // index for private key needed to sign / spend
}
func (t *TxStore) AddAdr(a btcutil.Address, kidx uint32) {
var ma MyAdr
ma.Address = a
ma.KeyIdx = kidx
t.Adrs = append(t.Adrs, ma)
return
}
func (t *TxStore) GimmeFilter() (*bloom.Filter, error) {
if len(t.Adrs) == 0 {
return nil, fmt.Errorf("no addresses to filter for")
}
f := bloom.NewFilter(uint32(len(t.Adrs)), 0, 0.001, wire.BloomUpdateNone)
for _, a := range t.Adrs {
f.Add(a.ScriptAddress())
}
return f, nil
}
// Ingest a tx into wallet, dealing with both gains and losses
func (t *TxStore) IngestTx(tx *wire.MsgTx) error {
err := t.AbsorbTx(tx)
if err != nil {
return err
}
err = t.ExpellTx(tx)
if err != nil {
return err
}
return nil
}
// Absorb money into wallet from a tx
func (t *TxStore) AbsorbTx(tx *wire.MsgTx) error {
if tx == nil {
return fmt.Errorf("Tried to add nil tx")
}
var hits uint32
var acq int64
// check if any of the tx's outputs match my adrs
for i, out := range tx.TxOut { // in each output of tx
for _, a := range t.Adrs { // compare to each adr we have
// more correct would be to check for full script
// contains could have false positive? (p2sh/p2pkh same hash ..?)
if bytes.Contains(out.PkScript, a.ScriptAddress()) { // hit
hits++
acq += out.Value
var newu Utxo
newu.KeyIdx = a.KeyIdx
newu.Txo = *out
var newop wire.OutPoint
newop.Hash = tx.TxSha()
newop.Index = uint32(i)
newu.Op = newop
t.Utxos = append(t.Utxos)
break
}
}
}
log.Printf("%d hits, acquired %d", hits, acq)
t.Sum += acq
return nil
}
// Expell money from wallet due to a tx
func (t *TxStore) ExpellTx(tx *wire.MsgTx) error {
if tx == nil {
return fmt.Errorf("Tried to add nil tx")
}
var hits uint32
var loss int64
for _, in := range tx.TxIn {
for i, myutxo := range t.Utxos {
if myutxo.Op == in.PreviousOutPoint {
hits++
loss += myutxo.Txo.Value
// delete from my utxo set
t.Utxos = append(t.Utxos[:i], t.Utxos[i+1:]...)
}
}
}
log.Printf("%d hits, lost %d", hits, loss)
t.Sum -= loss
return nil
}