neoneo-go/pkg/core/state/native_state.go
Roman Khimov aab18c3083 stackitem: introduce Convertible interface
We have a lot of native contract types that are converted to stack items
before serialization, then deserialized as stack items and converted back to
regular structures. stackitem.Convertible allows to remove a lot of repetitive
io.Serializable code.

This also introduces to/from converter in testserdes which unfortunately
required to change util tests to avoid circular references.
2021-07-19 15:42:42 +03:00

135 lines
3.5 KiB
Go

package state
import (
"crypto/elliptic"
"errors"
"fmt"
"math/big"
"github.com/nspcc-dev/neo-go/pkg/crypto/keys"
"github.com/nspcc-dev/neo-go/pkg/vm/stackitem"
)
// NEP17BalanceState represents balance state of a NEP17-token.
type NEP17BalanceState struct {
Balance big.Int
}
// NEOBalanceState represents balance state of a NEO-token.
type NEOBalanceState struct {
NEP17BalanceState
BalanceHeight uint32
VoteTo *keys.PublicKey
}
// NEP17BalanceStateFromBytes converts serialized NEP17BalanceState to structure.
func NEP17BalanceStateFromBytes(b []byte) (*NEP17BalanceState, error) {
balance := new(NEP17BalanceState)
err := balanceFromBytes(b, balance)
if err != nil {
return nil, err
}
return balance, nil
}
// Bytes returns serialized NEP17BalanceState.
func (s *NEP17BalanceState) Bytes() []byte {
return balanceToBytes(s)
}
func balanceFromBytes(b []byte, item stackitem.Convertible) error {
if len(b) == 0 {
return nil
}
return stackitem.DeserializeConvertible(b, item)
}
func balanceToBytes(item stackitem.Convertible) []byte {
data, err := stackitem.SerializeConvertible(item)
if err != nil {
panic(err)
}
return data
}
// ToStackItem implements stackitem.Convertible. It never returns an error.
func (s *NEP17BalanceState) ToStackItem() (stackitem.Item, error) {
return stackitem.NewStruct([]stackitem.Item{stackitem.NewBigInteger(&s.Balance)}), nil
}
// FromStackItem implements stackitem.Convertible.
func (s *NEP17BalanceState) FromStackItem(item stackitem.Item) error {
items, ok := item.Value().([]stackitem.Item)
if !ok {
return errors.New("not a struct")
}
if len(items) < 1 {
return errors.New("no balance value")
}
balance, err := items[0].TryInteger()
if err != nil {
return fmt.Errorf("invalid balance: %w", err)
}
s.Balance = *balance
return nil
}
// NEOBalanceStateFromBytes converts serialized NEOBalanceState to structure.
func NEOBalanceStateFromBytes(b []byte) (*NEOBalanceState, error) {
balance := new(NEOBalanceState)
err := balanceFromBytes(b, balance)
if err != nil {
return nil, err
}
return balance, nil
}
// Bytes returns serialized NEOBalanceState.
func (s *NEOBalanceState) Bytes() []byte {
return balanceToBytes(s)
}
// ToStackItem implements stackitem.Convertible interface. It never returns an error.
func (s *NEOBalanceState) ToStackItem() (stackitem.Item, error) {
resItem, _ := s.NEP17BalanceState.ToStackItem()
result := resItem.(*stackitem.Struct)
result.Append(stackitem.NewBigInteger(big.NewInt(int64(s.BalanceHeight))))
if s.VoteTo != nil {
result.Append(stackitem.NewByteArray(s.VoteTo.Bytes()))
} else {
result.Append(stackitem.Null{})
}
return result, nil
}
// FromStackItem converts stackitem.Item to NEOBalanceState.
func (s *NEOBalanceState) FromStackItem(item stackitem.Item) error {
structItem, ok := item.Value().([]stackitem.Item)
if !ok || len(structItem) < 3 {
return errors.New("invalid stackitem length")
}
balance, err := structItem[0].TryInteger()
if err != nil {
return fmt.Errorf("invalid balance stackitem: %w", err)
}
s.Balance = *balance
h, err := structItem[1].TryInteger()
if err != nil {
return fmt.Errorf("invalid heigh stackitem")
}
s.BalanceHeight = uint32(h.Int64())
if _, ok := structItem[2].(stackitem.Null); ok {
s.VoteTo = nil
return nil
}
bs, err := structItem[2].TryBytes()
if err != nil {
return fmt.Errorf("invalid public key stackitem: %w", err)
}
pub, err := keys.NewPublicKeyFromBytes(bs, elliptic.P256())
if err != nil {
return fmt.Errorf("invalid public key bytes: %w", err)
}
s.VoteTo = pub
return nil
}