core: store NEP5Transfer asset by ID instead of hash

To avoid problems with retrieving decimals for migrated contracts.

pkg/core/blockchain.go

@@ -707,14 +707,6 @@ func parseUint160(addr []byte) util.Uint160 {
 func (bc *Blockchain) processNEP5Transfer(cache *dao.Cached, h util.Uint256, b *block.Block, sc util.Uint160, from, to []byte, amount *big.Int) {
 	toAddr := parseUint160(to)
 	fromAddr := parseUint160(from)
-	transfer := &state.NEP5Transfer{
-		Asset:     sc,
-		From:      fromAddr,
-		To:        toAddr,
-		Block:     b.Index,
-		Timestamp: b.Timestamp,
-		Tx:        h,
-	}
 	var id int32
 	nativeContract := bc.contracts.ByHash(sc)
 	if nativeContract != nil {
@@ -726,6 +718,14 @@ func (bc *Blockchain) processNEP5Transfer(cache *dao.Cached, h util.Uint256, b *
 		}
 		id = assetContract.ID
 	}
+	transfer := &state.NEP5Transfer{
+		Asset:     id,
+		From:      fromAddr,
+		To:        toAddr,
+		Block:     b.Index,
+		Timestamp: b.Timestamp,
+		Tx:        h,
+	}
 	if !fromAddr.Equals(util.Uint160{}) {
 		balances, err := cache.GetNEP5Balances(fromAddr)
 		if err != nil {

pkg/core/state/nep5.go

@@ -26,8 +26,8 @@ type NEP5TransferLog struct {
 
 // NEP5Transfer represents a single NEP5 Transfer event.
 type NEP5Transfer struct {
-	// Asset is a NEP5 contract hash.
-	Asset util.Uint160
+	// Asset is a NEP5 contract ID.
+	Asset int32
 	// Address is the address of the sender.
 	From util.Uint160
 	// To is the address of the receiver.
@@ -132,7 +132,7 @@ func (t *NEP5Tracker) DecodeBinary(r *io.BinReader) {
 
 // EncodeBinary implements io.Serializable interface.
 func (t *NEP5Transfer) EncodeBinary(w *io.BinWriter) {
-	w.WriteBytes(t.Asset[:])
+	w.WriteU32LE(uint32(t.Asset))
 	w.WriteBytes(t.Tx[:])
 	w.WriteBytes(t.From[:])
 	w.WriteBytes(t.To[:])
@@ -150,7 +150,7 @@ func (t *NEP5Transfer) DecodeBinary(r *io.BinReader) {
 
 // DecodeBinaryReturnCount decodes NEP5Transfer and returns the number of bytes read.
 func (t *NEP5Transfer) DecodeBinaryReturnCount(r *io.BinReader) int {
-	r.ReadBytes(t.Asset[:])
+	t.Asset = int32(r.ReadU32LE())
 	r.ReadBytes(t.Tx[:])
 	r.ReadBytes(t.From[:])
 	r.ReadBytes(t.To[:])
@@ -160,5 +160,5 @@ func (t *NEP5Transfer) DecodeBinaryReturnCount(r *io.BinReader) int {
 	amountBytes := make([]byte, amountLen)
 	r.ReadBytes(amountBytes)
 	t.Amount = *bigint.FromBytes(amountBytes)
-	return util.Uint160Size*3 + 8 + 4 + (8 + len(amountBytes)) + +util.Uint256Size
+	return 4 + util.Uint160Size*2 + 8 + 4 + (8 + len(amountBytes)) + +util.Uint256Size
 }

pkg/core/state/nep5_test.go

@@ -50,7 +50,7 @@ func TestNEP5Tracker_EncodeBinary(t *testing.T) {
 
 func TestNEP5Transfer_DecodeBinary(t *testing.T) {
 	expected := &NEP5Transfer{
-		Asset:     util.Uint160{1, 2, 3},
+		Asset:     123,
 		From:      util.Uint160{5, 6, 7},
 		To:        util.Uint160{8, 9, 10},
 		Amount:    *big.NewInt(42),
@@ -78,7 +78,7 @@ func randomTransfer(r *rand.Rand) *NEP5Transfer {
 	return &NEP5Transfer{
 		Amount: *big.NewInt(int64(r.Uint64())),
 		Block:  r.Uint32(),
-		Asset:  random.Uint160(),
+		Asset:  int32(random.Int(10, 10000000)),
 		From:   random.Uint160(),
 		To:     random.Uint160(),
 		Tx:     random.Uint256(),

pkg/rpc/server/server.go

@@ -549,13 +549,17 @@ func (s *Server) getNEP5Transfers(ps request.Params) (interface{}, *response.Err
 	lg := s.chain.GetNEP5TransferLog(u)
 	cache := make(map[util.Uint160]int64)
 	err = lg.ForEach(func(tr *state.NEP5Transfer) error {
+		h, err := s.chain.GetContractScriptHash(tr.Asset)
+		if err != nil {
+			return nil
+		}
 		transfer := result.NEP5Transfer{
 			Timestamp: tr.Timestamp,
-			Asset:     tr.Asset,
+			Asset:     h,
 			Index:     tr.Block,
 			TxHash:    tr.Tx,
 		}
-		d, err := s.getDecimals(tr.Asset, cache)
+		d, err := s.getDecimals(h, cache)
 		if err != nil {
 			return nil
 		}