neo-go/pkg/core/native/native_neo.go

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package native
import (
"crypto/elliptic"
"math/big"
"sort"
"strings"
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"sync/atomic"
"github.com/nspcc-dev/neo-go/pkg/core/blockchainer"
"github.com/nspcc-dev/neo-go/pkg/core/dao"
"github.com/nspcc-dev/neo-go/pkg/core/interop"
"github.com/nspcc-dev/neo-go/pkg/core/interop/runtime"
"github.com/nspcc-dev/neo-go/pkg/core/state"
"github.com/nspcc-dev/neo-go/pkg/crypto/keys"
"github.com/nspcc-dev/neo-go/pkg/encoding/bigint"
"github.com/nspcc-dev/neo-go/pkg/smartcontract"
"github.com/nspcc-dev/neo-go/pkg/smartcontract/manifest"
"github.com/nspcc-dev/neo-go/pkg/util"
"github.com/nspcc-dev/neo-go/pkg/vm/stackitem"
"github.com/pkg/errors"
)
// NEO represents NEO native contract.
type NEO struct {
nep5TokenNative
GAS *GAS
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validators atomic.Value
}
// keyWithVotes is a serialized key with votes balance. It's not deserialized
// because some uses of it imply serialized-only usage and converting to
// PublicKey is quite expensive.
type keyWithVotes struct {
Key string
Votes *big.Int
}
const (
neoName = "NEO"
neoContractID = -1
// NEOTotalSupply is the total amount of NEO in the system.
NEOTotalSupply = 100000000
// prefixValidator is a prefix used to store validator's data.
prefixValidator = 33
)
var (
// validatorsCountKey is a key used to store validators count
// used to determine the real number of validators.
validatorsCountKey = []byte{15}
// nextValidatorsKey is a key used to store validators for the
// next block.
nextValidatorsKey = []byte{14}
)
// makeValidatorKey creates a key from account script hash.
func makeValidatorKey(key *keys.PublicKey) []byte {
b := key.Bytes()
// Don't create a new buffer.
b = append(b, 0)
copy(b[1:], b[0:])
b[0] = prefixValidator
return b
}
// NewNEO returns NEO native contract.
func NewNEO() *NEO {
n := &NEO{}
nep5 := newNEP5Native(neoName)
nep5.symbol = "neo"
nep5.decimals = 0
nep5.factor = 1
nep5.onPersist = chainOnPersist(nep5.OnPersist, n.OnPersist)
nep5.incBalance = n.increaseBalance
nep5.ContractID = neoContractID
n.nep5TokenNative = *nep5
n.validators.Store(keys.PublicKeys(nil))
onp := n.Methods["onPersist"]
onp.Func = getOnPersistWrapper(n.onPersist)
n.Methods["onPersist"] = onp
desc := newDescriptor("unclaimedGas", smartcontract.IntegerType,
manifest.NewParameter("account", smartcontract.Hash160Type),
manifest.NewParameter("end", smartcontract.IntegerType))
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md := newMethodAndPrice(n.unclaimedGas, 3000000, smartcontract.AllowStates)
n.AddMethod(md, desc, true)
desc = newDescriptor("registerValidator", smartcontract.BoolType,
manifest.NewParameter("pubkey", smartcontract.PublicKeyType))
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md = newMethodAndPrice(n.registerValidator, 5000000, smartcontract.AllowModifyStates)
n.AddMethod(md, desc, false)
desc = newDescriptor("vote", smartcontract.BoolType,
manifest.NewParameter("account", smartcontract.Hash160Type),
manifest.NewParameter("pubkeys", smartcontract.ArrayType))
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md = newMethodAndPrice(n.vote, 500000000, smartcontract.AllowModifyStates)
n.AddMethod(md, desc, false)
desc = newDescriptor("getRegisteredValidators", smartcontract.ArrayType)
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md = newMethodAndPrice(n.getRegisteredValidatorsCall, 100000000, smartcontract.AllowStates)
n.AddMethod(md, desc, true)
desc = newDescriptor("getValidators", smartcontract.ArrayType)
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md = newMethodAndPrice(n.getValidators, 100000000, smartcontract.AllowStates)
n.AddMethod(md, desc, true)
desc = newDescriptor("getNextBlockValidators", smartcontract.ArrayType)
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md = newMethodAndPrice(n.getNextBlockValidators, 100000000, smartcontract.AllowStates)
n.AddMethod(md, desc, true)
return n
}
// Initialize initializes NEO contract.
func (n *NEO) Initialize(ic *interop.Context) error {
if err := n.nep5TokenNative.Initialize(ic); err != nil {
return err
}
if n.nep5TokenNative.getTotalSupply(ic).Sign() != 0 {
return errors.New("already initialized")
}
h, vs, err := getStandbyValidatorsHash(ic)
if err != nil {
return err
}
n.mint(ic, h, big.NewInt(NEOTotalSupply))
for i := range vs {
if err := n.registerValidatorInternal(ic, vs[i]); err != nil {
return err
}
}
return nil
}
// OnPersist implements Contract interface.
func (n *NEO) OnPersist(ic *interop.Context) error {
pubs, err := n.GetValidatorsInternal(ic.Chain, ic.DAO)
if err != nil {
return err
}
si := new(state.StorageItem)
si.Value = pubs.Bytes()
return ic.DAO.PutStorageItem(n.ContractID, nextValidatorsKey, si)
}
func (n *NEO) increaseBalance(ic *interop.Context, h util.Uint160, si *state.StorageItem, amount *big.Int) error {
acc, err := state.NEOBalanceStateFromBytes(si.Value)
if err != nil {
return err
}
if amount.Sign() == -1 && acc.Balance.Cmp(new(big.Int).Neg(amount)) == -1 {
return errors.New("insufficient funds")
}
if err := n.distributeGas(ic, h, acc); err != nil {
return err
}
if amount.Sign() == 0 {
si.Value = acc.Bytes()
return nil
}
if len(acc.Votes) > 0 {
if err := n.ModifyAccountVotes(acc, ic.DAO, amount); err != nil {
return err
}
siVC := ic.DAO.GetStorageItem(n.ContractID, validatorsCountKey)
if siVC == nil {
return errors.New("validators count uninitialized")
}
vc, err := ValidatorsCountFromBytes(siVC.Value)
if err != nil {
return err
}
vc[len(acc.Votes)-1].Add(&vc[len(acc.Votes)-1], amount)
siVC.Value = vc.Bytes()
if err := ic.DAO.PutStorageItem(n.ContractID, validatorsCountKey, siVC); err != nil {
return err
}
}
acc.Balance.Add(&acc.Balance, amount)
if acc.Balance.Sign() != 0 {
si.Value = acc.Bytes()
} else {
si.Value = nil
}
return nil
}
func (n *NEO) distributeGas(ic *interop.Context, h util.Uint160, acc *state.NEOBalanceState) error {
if ic.Block == nil || ic.Block.Index == 0 {
return nil
}
gen := ic.Chain.CalculateClaimable(&acc.Balance, acc.BalanceHeight, ic.Block.Index)
acc.BalanceHeight = ic.Block.Index
n.GAS.mint(ic, h, gen)
return nil
}
func (n *NEO) unclaimedGas(ic *interop.Context, args []stackitem.Item) stackitem.Item {
u := toUint160(args[0])
end := uint32(toBigInt(args[1]).Int64())
bs, err := ic.DAO.GetNEP5Balances(u)
if err != nil {
panic(err)
}
tr := bs.Trackers[n.Hash]
gen := ic.Chain.CalculateClaimable(&tr.Balance, tr.LastUpdatedBlock, end)
return stackitem.NewBigInteger(gen)
}
func (n *NEO) registerValidator(ic *interop.Context, args []stackitem.Item) stackitem.Item {
err := n.registerValidatorInternal(ic, toPublicKey(args[0]))
return stackitem.NewBool(err == nil)
}
func (n *NEO) registerValidatorInternal(ic *interop.Context, pub *keys.PublicKey) error {
key := makeValidatorKey(pub)
si := ic.DAO.GetStorageItem(n.ContractID, key)
if si != nil {
return errors.New("already registered")
}
si = new(state.StorageItem)
// Zero value.
si.Value = []byte{}
return ic.DAO.PutStorageItem(n.ContractID, key, si)
}
func (n *NEO) vote(ic *interop.Context, args []stackitem.Item) stackitem.Item {
acc := toUint160(args[0])
arr := args[1].Value().([]stackitem.Item)
var pubs keys.PublicKeys
for i := range arr {
pub := new(keys.PublicKey)
bs, err := arr[i].TryBytes()
if err != nil {
panic(err)
} else if err := pub.DecodeBytes(bs); err != nil {
panic(err)
}
pubs = append(pubs, pub)
}
err := n.VoteInternal(ic, acc, pubs)
return stackitem.NewBool(err == nil)
}
// VoteInternal votes from account h for validarors specified in pubs.
func (n *NEO) VoteInternal(ic *interop.Context, h util.Uint160, pubs keys.PublicKeys) error {
ok, err := runtime.CheckHashedWitness(ic, h)
if err != nil {
return err
} else if !ok {
return errors.New("invalid signature")
}
key := makeAccountKey(h)
si := ic.DAO.GetStorageItem(n.ContractID, key)
if si == nil {
return errors.New("invalid account")
}
acc, err := state.NEOBalanceStateFromBytes(si.Value)
if err != nil {
return err
}
if err := n.ModifyAccountVotes(acc, ic.DAO, new(big.Int).Neg(&acc.Balance)); err != nil {
return err
}
pubs = pubs.Unique()
// Check validators registration.
var newPubs keys.PublicKeys
for _, pub := range pubs {
if ic.DAO.GetStorageItem(n.ContractID, makeValidatorKey(pub)) == nil {
continue
}
newPubs = append(newPubs, pub)
}
if lp, lv := len(newPubs), len(acc.Votes); lp != lv {
var si *state.StorageItem
var vc *ValidatorsCount
var err error
si = ic.DAO.GetStorageItem(n.ContractID, validatorsCountKey)
if si == nil {
// The first voter.
si = new(state.StorageItem)
vc = new(ValidatorsCount)
} else {
vc, err = ValidatorsCountFromBytes(si.Value)
if err != nil {
return err
}
}
if lv > 0 {
vc[lv-1].Sub(&vc[lv-1], &acc.Balance)
}
if len(newPubs) > 0 {
vc[lp-1].Add(&vc[lp-1], &acc.Balance)
}
si.Value = vc.Bytes()
if err := ic.DAO.PutStorageItem(n.ContractID, validatorsCountKey, si); err != nil {
return err
}
}
acc.Votes = newPubs
if err := n.ModifyAccountVotes(acc, ic.DAO, &acc.Balance); err != nil {
return err
}
si.Value = acc.Bytes()
return ic.DAO.PutStorageItem(n.ContractID, key, si)
}
// ModifyAccountVotes modifies votes of the specified account by value (can be negative).
func (n *NEO) ModifyAccountVotes(acc *state.NEOBalanceState, d dao.DAO, value *big.Int) error {
for _, vote := range acc.Votes {
key := makeValidatorKey(vote)
si := d.GetStorageItem(n.ContractID, key)
if si == nil {
return errors.New("invalid validator")
}
votes := bigint.FromBytes(si.Value)
votes.Add(votes, value)
si.Value = bigint.ToPreallocatedBytes(votes, si.Value[:0])
if err := d.PutStorageItem(n.ContractID, key, si); err != nil {
return err
}
}
n.validators.Store(keys.PublicKeys(nil))
return nil
}
func (n *NEO) getRegisteredValidators(d dao.DAO) ([]keyWithVotes, error) {
siMap, err := d.GetStorageItemsWithPrefix(n.ContractID, []byte{prefixValidator})
if err != nil {
return nil, err
}
arr := make([]keyWithVotes, 0, len(siMap))
for key, si := range siMap {
votes := bigint.FromBytes(si.Value)
arr = append(arr, keyWithVotes{key, votes})
}
sort.Slice(arr, func(i, j int) bool { return strings.Compare(arr[i].Key, arr[j].Key) == -1 })
return arr, nil
}
// GetRegisteredValidators returns current registered validators list with keys
// and votes.
func (n *NEO) GetRegisteredValidators(d dao.DAO) ([]state.Validator, error) {
kvs, err := n.getRegisteredValidators(d)
if err != nil {
return nil, err
}
arr := make([]state.Validator, len(kvs))
for i := range kvs {
arr[i].Key, err = keys.NewPublicKeyFromBytes([]byte(kvs[i].Key), elliptic.P256())
if err != nil {
return nil, err
}
arr[i].Votes = kvs[i].Votes
}
return arr, nil
}
func (n *NEO) getRegisteredValidatorsCall(ic *interop.Context, _ []stackitem.Item) stackitem.Item {
validators, err := n.getRegisteredValidators(ic.DAO)
if err != nil {
panic(err)
}
arr := make([]stackitem.Item, len(validators))
for i := range validators {
arr[i] = stackitem.NewStruct([]stackitem.Item{
stackitem.NewByteArray([]byte(validators[i].Key)),
stackitem.NewBigInteger(validators[i].Votes),
})
}
return stackitem.NewArray(arr)
}
// GetValidatorsInternal returns a list of current validators.
func (n *NEO) GetValidatorsInternal(bc blockchainer.Blockchainer, d dao.DAO) (keys.PublicKeys, error) {
if vals := n.validators.Load().(keys.PublicKeys); vals != nil {
return vals.Copy(), nil
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}
standByValidators := bc.GetStandByValidators()
si := d.GetStorageItem(n.ContractID, validatorsCountKey)
if si == nil {
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n.validators.Store(standByValidators)
return standByValidators.Copy(), nil
}
validatorsCount, err := ValidatorsCountFromBytes(si.Value)
if err != nil {
return nil, err
}
validators, err := n.GetRegisteredValidators(d)
if err != nil {
return nil, err
}
sort.Slice(validators, func(i, j int) bool {
// The most-voted validators should end up in the front of the list.
cmp := validators[i].Votes.Cmp(validators[j].Votes)
if cmp != 0 {
return cmp > 0
}
// Ties are broken with public keys.
return validators[i].Key.Cmp(validators[j].Key) == -1
})
count := validatorsCount.GetWeightedAverage()
if count < len(standByValidators) {
count = len(standByValidators)
}
uniqueSBValidators := standByValidators.Unique()
result := keys.PublicKeys{}
for _, validator := range validators {
if validator.Votes.Sign() > 0 || uniqueSBValidators.Contains(validator.Key) {
result = append(result, validator.Key)
}
}
if result.Len() >= count {
result = result[:count]
} else {
for i := 0; i < uniqueSBValidators.Len() && result.Len() < count; i++ {
if !result.Contains(uniqueSBValidators[i]) {
result = append(result, uniqueSBValidators[i])
}
}
}
sort.Sort(result)
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n.validators.Store(result)
return result, nil
}
func (n *NEO) getValidators(ic *interop.Context, _ []stackitem.Item) stackitem.Item {
result, err := n.GetValidatorsInternal(ic.Chain, ic.DAO)
if err != nil {
panic(err)
}
return pubsToArray(result)
}
func (n *NEO) getNextBlockValidators(ic *interop.Context, _ []stackitem.Item) stackitem.Item {
result, err := n.getNextBlockValidatorsInternal(ic.Chain, ic.DAO)
if err != nil {
panic(err)
}
return pubsToArray(result)
}
// GetNextBlockValidatorsInternal returns next block validators.
func (n *NEO) GetNextBlockValidatorsInternal(bc blockchainer.Blockchainer, d dao.DAO) (keys.PublicKeys, error) {
pubs, err := n.getNextBlockValidatorsInternal(bc, d)
if err != nil {
return nil, err
}
return pubs.Copy(), nil
}
// getNextBlockValidatorsInternal returns next block validators.
func (n *NEO) getNextBlockValidatorsInternal(bc blockchainer.Blockchainer, d dao.DAO) (keys.PublicKeys, error) {
si := d.GetStorageItem(n.ContractID, nextValidatorsKey)
if si == nil {
return n.GetValidatorsInternal(bc, d)
}
pubs := keys.PublicKeys{}
err := pubs.DecodeBytes(si.Value)
if err != nil {
return nil, err
}
return pubs, nil
}
func pubsToArray(pubs keys.PublicKeys) stackitem.Item {
arr := make([]stackitem.Item, len(pubs))
for i := range pubs {
arr[i] = stackitem.NewByteArray(pubs[i].Bytes())
}
return stackitem.NewArray(arr)
}
func toPublicKey(s stackitem.Item) *keys.PublicKey {
buf, err := s.TryBytes()
if err != nil {
panic(err)
}
pub := new(keys.PublicKey)
if err := pub.DecodeBytes(buf); err != nil {
panic(err)
}
return pub
}