neoneo-go/pkg/core/native/native_neo.go
2021-01-18 00:38:23 +03:00

926 lines
27 KiB
Go

package native
import (
"crypto/elliptic"
"encoding/binary"
"errors"
"fmt"
"math/big"
"sort"
"strings"
"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/native/nativenames"
"github.com/nspcc-dev/neo-go/pkg/core/state"
"github.com/nspcc-dev/neo-go/pkg/core/storage"
"github.com/nspcc-dev/neo-go/pkg/crypto/hash"
"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/io"
"github.com/nspcc-dev/neo-go/pkg/smartcontract"
"github.com/nspcc-dev/neo-go/pkg/smartcontract/callflag"
"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"
)
// NEO represents NEO native contract.
type NEO struct {
nep17TokenNative
GAS *GAS
// gasPerBlock represents current value of generated gas per block.
// It is append-only and doesn't need to be copied when used.
gasPerBlock atomic.Value
gasPerBlockChanged atomic.Value
votesChanged atomic.Value
nextValidators atomic.Value
validators atomic.Value
// committee contains cached committee members and their votes.
// It is updated once in a while depending on committee size
// (every 28 blocks for mainnet). It's value
// is always equal to value stored by `prefixCommittee`.
committee atomic.Value
// committeeHash contains script hash of the committee.
committeeHash atomic.Value
}
const (
neoContractID = -2
// NEOTotalSupply is the total amount of NEO in the system.
NEOTotalSupply = 100000000
// prefixCandidate is a prefix used to store validator's data.
prefixCandidate = 33
// prefixVotersCount is a prefix for storing total amount of NEO of voters.
prefixVotersCount = 1
// prefixVoterRewardPerCommittee is a prefix for storing committee GAS reward.
prefixVoterRewardPerCommittee = 23
// voterRewardFactor is a factor by which voter reward per committee is multiplied
// to make calculations more precise.
voterRewardFactor = 100_000_000
// prefixGasPerBlock is a prefix for storing amount of GAS generated per block.
prefixGASPerBlock = 29
// effectiveVoterTurnout represents minimal ratio of total supply to total amount voted value
// which is require to use non-standby validators.
effectiveVoterTurnout = 5
// neoHolderRewardRatio is a percent of generated GAS that is distributed to NEO holders.
neoHolderRewardRatio = 10
// neoHolderRewardRatio is a percent of generated GAS that is distributed to committee.
committeeRewardRatio = 10
// neoHolderRewardRatio is a percent of generated GAS that is distributed to voters.
voterRewardRatio = 80
)
var (
// prefixCommittee is a key used to store committee.
prefixCommittee = []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] = prefixCandidate
return b
}
// newNEO returns NEO native contract.
func newNEO() *NEO {
n := &NEO{}
nep17 := newNEP17Native(nativenames.Neo, neoContractID)
nep17.symbol = "NEO"
nep17.decimals = 0
nep17.factor = 1
nep17.incBalance = n.increaseBalance
n.nep17TokenNative = *nep17
n.votesChanged.Store(true)
n.nextValidators.Store(keys.PublicKeys(nil))
n.validators.Store(keys.PublicKeys(nil))
n.committee.Store(keysWithVotes(nil))
n.committeeHash.Store(util.Uint160{})
desc := newDescriptor("unclaimedGas", smartcontract.IntegerType,
manifest.NewParameter("account", smartcontract.Hash160Type),
manifest.NewParameter("end", smartcontract.IntegerType))
md := newMethodAndPrice(n.unclaimedGas, 3000000, callflag.ReadStates)
n.AddMethod(md, desc)
desc = newDescriptor("registerCandidate", smartcontract.BoolType,
manifest.NewParameter("pubkey", smartcontract.ByteArrayType))
md = newMethodAndPrice(n.registerCandidate, 5000000, callflag.WriteStates)
n.AddMethod(md, desc)
desc = newDescriptor("unregisterCandidate", smartcontract.BoolType,
manifest.NewParameter("pubkey", smartcontract.ByteArrayType))
md = newMethodAndPrice(n.unregisterCandidate, 5000000, callflag.WriteStates)
n.AddMethod(md, desc)
desc = newDescriptor("vote", smartcontract.BoolType,
manifest.NewParameter("account", smartcontract.Hash160Type),
manifest.NewParameter("pubkey", smartcontract.ByteArrayType))
md = newMethodAndPrice(n.vote, 5000000, callflag.WriteStates)
n.AddMethod(md, desc)
desc = newDescriptor("getCandidates", smartcontract.ArrayType)
md = newMethodAndPrice(n.getCandidatesCall, 100000000, callflag.ReadStates)
n.AddMethod(md, desc)
desc = newDescriptor("getСommittee", smartcontract.ArrayType)
md = newMethodAndPrice(n.getCommittee, 100000000, callflag.ReadStates)
n.AddMethod(md, desc)
desc = newDescriptor("getNextBlockValidators", smartcontract.ArrayType)
md = newMethodAndPrice(n.getNextBlockValidators, 100000000, callflag.ReadStates)
n.AddMethod(md, desc)
desc = newDescriptor("getGasPerBlock", smartcontract.IntegerType)
md = newMethodAndPrice(n.getGASPerBlock, 100_0000, callflag.ReadStates)
n.AddMethod(md, desc)
desc = newDescriptor("setGasPerBlock", smartcontract.BoolType,
manifest.NewParameter("gasPerBlock", smartcontract.IntegerType))
md = newMethodAndPrice(n.setGASPerBlock, 500_0000, callflag.WriteStates)
n.AddMethod(md, desc)
return n
}
// Initialize initializes NEO contract.
func (n *NEO) Initialize(ic *interop.Context) error {
if err := n.nep17TokenNative.Initialize(ic); err != nil {
return err
}
if n.nep17TokenNative.getTotalSupply(ic.DAO).Sign() != 0 {
return errors.New("already initialized")
}
committee := ic.Chain.GetStandByCommittee()
cvs := toKeysWithVotes(committee)
err := n.updateCache(cvs, ic.Chain)
if err != nil {
return err
}
err = ic.DAO.PutStorageItem(n.ContractID, prefixCommittee, &state.StorageItem{Value: cvs.Bytes()})
if err != nil {
return err
}
h, err := getStandbyValidatorsHash(ic)
if err != nil {
return err
}
n.mint(ic, h, big.NewInt(NEOTotalSupply), false)
var index uint32 = 0
value := big.NewInt(5 * GASFactor)
err = n.putGASRecord(ic.DAO, index, value)
if err != nil {
return err
}
gr := &gasRecord{{Index: index, GASPerBlock: *value}}
n.gasPerBlock.Store(*gr)
n.gasPerBlockChanged.Store(false)
err = ic.DAO.PutStorageItem(n.ContractID, []byte{prefixVotersCount}, &state.StorageItem{Value: []byte{}})
if err != nil {
return err
}
return nil
}
// InitializeCache initializes all NEO cache with the proper values from storage.
// Cache initialisation should be done apart from Initialize because Initialize is
// called only when deploying native contracts.
func (n *NEO) InitializeCache(bc blockchainer.Blockchainer, d dao.DAO) error {
var committee = keysWithVotes{}
si := d.GetStorageItem(n.ContractID, prefixCommittee)
if err := committee.DecodeBytes(si.Value); err != nil {
return err
}
if err := n.updateCache(committee, bc); err != nil {
return err
}
gr, err := n.getSortedGASRecordFromDAO(d)
if err != nil {
return err
}
n.gasPerBlock.Store(gr)
n.gasPerBlockChanged.Store(false)
return nil
}
func (n *NEO) updateCache(cvs keysWithVotes, bc blockchainer.Blockchainer) error {
n.committee.Store(cvs)
var committee = n.GetCommitteeMembers()
script, err := smartcontract.CreateMajorityMultiSigRedeemScript(committee.Copy())
if err != nil {
return err
}
n.committeeHash.Store(hash.Hash160(script))
nextVals := committee[:bc.GetConfig().ValidatorsCount].Copy()
sort.Sort(nextVals)
n.nextValidators.Store(nextVals)
return nil
}
func (n *NEO) updateCommittee(ic *interop.Context) error {
votesChanged := n.votesChanged.Load().(bool)
if !votesChanged {
// We need to put in storage anyway, as it affects dumps
committee := n.committee.Load().(keysWithVotes)
si := &state.StorageItem{Value: committee.Bytes()}
return ic.DAO.PutStorageItem(n.ContractID, prefixCommittee, si)
}
_, cvs, err := n.computeCommitteeMembers(ic.Chain, ic.DAO)
if err != nil {
return err
}
if err := n.updateCache(cvs, ic.Chain); err != nil {
return err
}
n.votesChanged.Store(false)
si := &state.StorageItem{Value: cvs.Bytes()}
return ic.DAO.PutStorageItem(n.ContractID, prefixCommittee, si)
}
// ShouldUpdateCommittee returns true if committee is updated at block h.
func ShouldUpdateCommittee(h uint32, bc blockchainer.Blockchainer) bool {
cfg := bc.GetConfig()
r := len(cfg.StandbyCommittee)
return h%uint32(r) == 0
}
// OnPersist implements Contract interface.
func (n *NEO) OnPersist(ic *interop.Context) error {
if ShouldUpdateCommittee(ic.Block.Index, ic.Chain) {
if err := n.updateCommittee(ic); err != nil {
return err
}
}
return nil
}
// PostPersist implements Contract interface.
func (n *NEO) PostPersist(ic *interop.Context) error {
gas := n.GetGASPerBlock(ic.DAO, ic.Block.Index)
pubs := n.GetCommitteeMembers()
committeeSize := len(ic.Chain.GetConfig().StandbyCommittee)
index := int(ic.Block.Index) % committeeSize
committeeReward := new(big.Int).Mul(gas, big.NewInt(committeeRewardRatio))
n.GAS.mint(ic, pubs[index].GetScriptHash(), committeeReward.Div(committeeReward, big.NewInt(100)), false)
if ShouldUpdateCommittee(ic.Block.Index, ic.Chain) {
var voterReward = big.NewInt(voterRewardRatio)
voterReward.Mul(voterReward, gas)
voterReward.Mul(voterReward, big.NewInt(voterRewardFactor*int64(committeeSize)))
var validatorsCount = ic.Chain.GetConfig().ValidatorsCount
voterReward.Div(voterReward, big.NewInt(int64(committeeSize+validatorsCount)))
voterReward.Div(voterReward, big.NewInt(100))
var cs = n.committee.Load().(keysWithVotes)
var si = new(state.StorageItem)
var key = make([]byte, 38)
for i := range cs {
if cs[i].Votes.Sign() > 0 {
tmp := big.NewInt(1)
if i < validatorsCount {
tmp = big.NewInt(2)
}
tmp.Mul(tmp, voterReward)
tmp.Div(tmp, cs[i].Votes)
key = makeVoterKey([]byte(cs[i].Key), key)
var reward = n.getGASPerVote(ic.DAO, key[:34], ic.Block.Index+1)
tmp.Add(tmp, &reward[0])
binary.BigEndian.PutUint32(key[34:], ic.Block.Index+1)
si.Value = bigint.ToBytes(tmp)
if err := ic.DAO.PutStorageItem(n.ContractID, key, si); err != nil {
return err
}
}
}
}
if n.gasPerBlockChanged.Load().(bool) {
gr, err := n.getSortedGASRecordFromDAO(ic.DAO)
if err != nil {
panic(err)
}
n.gasPerBlock.Store(gr)
n.gasPerBlockChanged.Store(false)
}
return nil
}
func (n *NEO) getGASPerVote(d dao.DAO, key []byte, index ...uint32) []big.Int {
var max = make([]uint32, len(index))
var reward = make([]big.Int, len(index))
var si state.StorageItem
d.Seek(n.ContractID, key, func(k, v []byte) {
if len(k) == 4 {
num := binary.BigEndian.Uint32(k)
for i, ind := range index {
if max[i] < num && num <= ind {
max[i] = num
r := io.NewBinReaderFromBuf(v)
si.DecodeBinary(r)
if r.Err != nil {
return
}
reward[i] = *bigint.FromBytes(si.Value)
}
}
}
})
return reward
}
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 err := n.ModifyAccountVotes(acc, ic.DAO, amount, false); err != nil {
return err
}
if acc.VoteTo != nil {
if err := n.modifyVoterTurnout(ic.DAO, amount); 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, err := n.calculateBonus(ic.DAO, acc.VoteTo, &acc.Balance, acc.BalanceHeight, ic.Block.Index)
if err != nil {
return err
}
acc.BalanceHeight = ic.Block.Index
n.GAS.mint(ic, h, gen, true)
return nil
}
func (n *NEO) unclaimedGas(ic *interop.Context, args []stackitem.Item) stackitem.Item {
u := toUint160(args[0])
end := uint32(toBigInt(args[1]).Int64())
gen, err := n.CalculateBonus(ic.DAO, u, end)
if err != nil {
panic(err)
}
return stackitem.NewBigInteger(gen)
}
func (n *NEO) getGASPerBlock(ic *interop.Context, _ []stackitem.Item) stackitem.Item {
gas := n.GetGASPerBlock(ic.DAO, ic.Block.Index)
return stackitem.NewBigInteger(gas)
}
func (n *NEO) getSortedGASRecordFromDAO(d dao.DAO) (gasRecord, error) {
grMap, err := d.GetStorageItemsWithPrefix(n.ContractID, []byte{prefixGASPerBlock})
if err != nil {
return gasRecord{}, fmt.Errorf("failed to get gas records from storage: %w", err)
}
var (
i int
gr = make(gasRecord, len(grMap))
)
for indexBytes, gasValue := range grMap {
gr[i] = gasIndexPair{
Index: binary.BigEndian.Uint32([]byte(indexBytes)),
GASPerBlock: *bigint.FromBytes(gasValue.Value),
}
i++
}
sort.Slice(gr, func(i, j int) bool {
return gr[i].Index < gr[j].Index
})
return gr, nil
}
// GetGASPerBlock returns gas generated for block with provided index.
func (n *NEO) GetGASPerBlock(d dao.DAO, index uint32) *big.Int {
var (
gr gasRecord
err error
)
if n.gasPerBlockChanged.Load().(bool) {
gr, err = n.getSortedGASRecordFromDAO(d)
if err != nil {
panic(err)
}
} else {
gr = n.gasPerBlock.Load().(gasRecord)
}
for i := len(gr) - 1; i >= 0; i-- {
if gr[i].Index <= index {
g := gr[i].GASPerBlock
return &g
}
}
panic("contract not initialized")
}
// GetCommitteeAddress returns address of the committee.
func (n *NEO) GetCommitteeAddress() util.Uint160 {
return n.committeeHash.Load().(util.Uint160)
}
func (n *NEO) setGASPerBlock(ic *interop.Context, args []stackitem.Item) stackitem.Item {
gas := toBigInt(args[0])
ok, err := n.SetGASPerBlock(ic, ic.Block.Index+1, gas)
if err != nil {
panic(err)
}
return stackitem.NewBool(ok)
}
// SetGASPerBlock sets gas generated for blocks after index.
func (n *NEO) SetGASPerBlock(ic *interop.Context, index uint32, gas *big.Int) (bool, error) {
if gas.Sign() == -1 || gas.Cmp(big.NewInt(10*GASFactor)) == 1 {
return false, errors.New("invalid value for GASPerBlock")
}
h := n.GetCommitteeAddress()
ok, err := runtime.CheckHashedWitness(ic, h)
if err != nil || !ok {
return ok, err
}
n.gasPerBlockChanged.Store(true)
return true, n.putGASRecord(ic.DAO, index, gas)
}
func (n *NEO) dropCandidateIfZero(d dao.DAO, pub *keys.PublicKey, c *candidate) (bool, error) {
if c.Registered || c.Votes.Sign() != 0 {
return false, nil
}
if err := d.DeleteStorageItem(n.ContractID, makeValidatorKey(pub)); err != nil {
return true, err
}
var toRemove []string
d.Seek(n.ContractID, makeVoterKey(pub.Bytes()), func(k, v []byte) {
toRemove = append(toRemove, string(k))
})
for i := range toRemove {
if err := d.DeleteStorageItem(n.ContractID, []byte(toRemove[i])); err != nil {
return true, err
}
}
return true, nil
}
func makeVoterKey(pub []byte, prealloc ...[]byte) []byte {
var key []byte
if len(prealloc) != 0 {
key = prealloc[0]
} else {
key = make([]byte, 34, 38)
}
key[0] = prefixVoterRewardPerCommittee
copy(key[1:], pub)
return key
}
// CalculateBonus calculates amount of gas generated for holding value NEO from start to end block
// and having voted for active committee member.
func (n *NEO) CalculateBonus(d dao.DAO, acc util.Uint160, end uint32) (*big.Int, error) {
key := makeAccountKey(acc)
si := d.GetStorageItem(n.ContractID, key)
if si == nil {
return nil, storage.ErrKeyNotFound
}
st, err := state.NEOBalanceStateFromBytes(si.Value)
if err != nil {
return nil, err
}
return n.calculateBonus(d, st.VoteTo, &st.Balance, st.BalanceHeight, end)
}
func (n *NEO) calculateBonus(d dao.DAO, vote *keys.PublicKey, value *big.Int, start, end uint32) (*big.Int, error) {
r, err := n.CalculateNEOHolderReward(d, value, start, end)
if err != nil || vote == nil {
return r, err
}
var key = makeVoterKey(vote.Bytes())
var reward = n.getGASPerVote(d, key, start, end)
var tmp = new(big.Int).Sub(&reward[1], &reward[0])
tmp.Mul(tmp, value)
tmp.Div(tmp, big.NewInt(voterRewardFactor))
tmp.Add(tmp, r)
return tmp, nil
}
// CalculateNEOHolderReward return GAS reward for holding `value` of NEO from start to end block.
func (n *NEO) CalculateNEOHolderReward(d dao.DAO, value *big.Int, start, end uint32) (*big.Int, error) {
if value.Sign() == 0 || start >= end {
return big.NewInt(0), nil
} else if value.Sign() < 0 {
return nil, errors.New("negative value")
}
var (
gr gasRecord
err error
)
if !n.gasPerBlockChanged.Load().(bool) {
gr = n.gasPerBlock.Load().(gasRecord)
} else {
gr, err = n.getSortedGASRecordFromDAO(d)
if err != nil {
return nil, err
}
}
var sum, tmp big.Int
for i := len(gr) - 1; i >= 0; i-- {
if gr[i].Index >= end {
continue
} else if gr[i].Index <= start {
tmp.SetInt64(int64(end - start))
tmp.Mul(&tmp, &gr[i].GASPerBlock)
sum.Add(&sum, &tmp)
break
}
tmp.SetInt64(int64(end - gr[i].Index))
tmp.Mul(&tmp, &gr[i].GASPerBlock)
sum.Add(&sum, &tmp)
end = gr[i].Index
}
res := new(big.Int).Mul(value, &sum)
res.Mul(res, tmp.SetInt64(neoHolderRewardRatio))
res.Div(res, tmp.SetInt64(100*NEOTotalSupply))
return res, nil
}
func (n *NEO) registerCandidate(ic *interop.Context, args []stackitem.Item) stackitem.Item {
pub := toPublicKey(args[0])
ok, err := runtime.CheckKeyedWitness(ic, pub)
if err != nil {
panic(err)
} else if !ok {
return stackitem.NewBool(false)
}
err = n.RegisterCandidateInternal(ic, pub)
return stackitem.NewBool(err == nil)
}
// RegisterCandidateInternal registers pub as a new candidate.
func (n *NEO) RegisterCandidateInternal(ic *interop.Context, pub *keys.PublicKey) error {
key := makeValidatorKey(pub)
si := ic.DAO.GetStorageItem(n.ContractID, key)
if si == nil {
c := &candidate{Registered: true}
si = &state.StorageItem{Value: c.Bytes()}
} else {
c := new(candidate).FromBytes(si.Value)
c.Registered = true
si.Value = c.Bytes()
}
return ic.DAO.PutStorageItem(n.ContractID, key, si)
}
func (n *NEO) unregisterCandidate(ic *interop.Context, args []stackitem.Item) stackitem.Item {
pub := toPublicKey(args[0])
ok, err := runtime.CheckKeyedWitness(ic, pub)
if err != nil {
panic(err)
} else if !ok {
return stackitem.NewBool(false)
}
err = n.UnregisterCandidateInternal(ic, pub)
return stackitem.NewBool(err == nil)
}
// UnregisterCandidateInternal unregisters pub as a candidate.
func (n *NEO) UnregisterCandidateInternal(ic *interop.Context, pub *keys.PublicKey) error {
key := makeValidatorKey(pub)
si := ic.DAO.GetStorageItem(n.ContractID, key)
if si == nil {
return nil
}
n.validators.Store(keys.PublicKeys(nil))
c := new(candidate).FromBytes(si.Value)
c.Registered = false
ok, err := n.dropCandidateIfZero(ic.DAO, pub, c)
if ok {
return err
}
si.Value = c.Bytes()
return ic.DAO.PutStorageItem(n.ContractID, key, si)
}
func (n *NEO) vote(ic *interop.Context, args []stackitem.Item) stackitem.Item {
acc := toUint160(args[0])
var pub *keys.PublicKey
if _, ok := args[1].(stackitem.Null); !ok {
pub = toPublicKey(args[1])
}
err := n.VoteInternal(ic, acc, pub)
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, pub *keys.PublicKey) 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 (acc.VoteTo == nil) != (pub == nil) {
val := &acc.Balance
if pub == nil {
val = new(big.Int).Neg(val)
}
if err := n.modifyVoterTurnout(ic.DAO, val); err != nil {
return err
}
}
if err := n.distributeGas(ic, h, acc); err != nil {
return err
}
if err := n.ModifyAccountVotes(acc, ic.DAO, new(big.Int).Neg(&acc.Balance), false); err != nil {
return err
}
acc.VoteTo = pub
if err := n.ModifyAccountVotes(acc, ic.DAO, &acc.Balance, true); 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).
// typ specifies if this modify is occurring during transfer or vote (with old or new validator).
func (n *NEO) ModifyAccountVotes(acc *state.NEOBalanceState, d dao.DAO, value *big.Int, isNewVote bool) error {
n.votesChanged.Store(true)
if acc.VoteTo != nil {
key := makeValidatorKey(acc.VoteTo)
si := d.GetStorageItem(n.ContractID, key)
if si == nil {
return errors.New("invalid validator")
}
cd := new(candidate).FromBytes(si.Value)
cd.Votes.Add(&cd.Votes, value)
if !isNewVote {
ok, err := n.dropCandidateIfZero(d, acc.VoteTo, cd)
if ok {
return err
}
} else if !cd.Registered {
return errors.New("validator must be registered")
}
n.validators.Store(keys.PublicKeys(nil))
si.Value = cd.Bytes()
return d.PutStorageItem(n.ContractID, key, si)
}
return nil
}
func (n *NEO) getCandidates(d dao.DAO, sortByKey bool) ([]keyWithVotes, error) {
siMap, err := d.GetStorageItemsWithPrefix(n.ContractID, []byte{prefixCandidate})
if err != nil {
return nil, err
}
arr := make([]keyWithVotes, 0, len(siMap))
for key, si := range siMap {
c := new(candidate).FromBytes(si.Value)
if c.Registered {
arr = append(arr, keyWithVotes{Key: key, Votes: &c.Votes})
}
}
if sortByKey {
sort.Slice(arr, func(i, j int) bool { return strings.Compare(arr[i].Key[1:], arr[j].Key[1:]) == -1 })
} else {
sort.Slice(arr, func(i, j int) bool {
// The most-voted validators should end up in the front of the list.
cmp := arr[i].Votes.Cmp(arr[j].Votes)
if cmp != 0 {
return cmp > 0
}
// Ties are broken with public keys.
return strings.Compare(arr[i].Key[1:], arr[j].Key[1:]) == -1
})
}
return arr, nil
}
// GetCandidates returns current registered validators list with keys
// and votes.
func (n *NEO) GetCandidates(d dao.DAO) ([]state.Validator, error) {
kvs, err := n.getCandidates(d, true)
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) getCandidatesCall(ic *interop.Context, _ []stackitem.Item) stackitem.Item {
validators, err := n.getCandidates(ic.DAO, true)
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)
}
// ComputeNextBlockValidators returns an actual list of current validators.
func (n *NEO) ComputeNextBlockValidators(bc blockchainer.Blockchainer, d dao.DAO) (keys.PublicKeys, error) {
if vals := n.validators.Load().(keys.PublicKeys); vals != nil {
return vals.Copy(), nil
}
result, _, err := n.computeCommitteeMembers(bc, d)
if err != nil {
return nil, err
}
result = result[:bc.GetConfig().ValidatorsCount]
sort.Sort(result)
n.validators.Store(result)
return result, nil
}
func (n *NEO) getCommittee(ic *interop.Context, _ []stackitem.Item) stackitem.Item {
pubs := n.GetCommitteeMembers()
sort.Sort(pubs)
return pubsToArray(pubs)
}
func (n *NEO) modifyVoterTurnout(d dao.DAO, amount *big.Int) error {
key := []byte{prefixVotersCount}
si := d.GetStorageItem(n.ContractID, key)
if si == nil {
return errors.New("voters count not found")
}
votersCount := bigint.FromBytes(si.Value)
votersCount.Add(votersCount, amount)
si.Value = bigint.ToBytes(votersCount)
return d.PutStorageItem(n.ContractID, key, si)
}
// GetCommitteeMembers returns public keys of nodes in committee using cached value.
func (n *NEO) GetCommitteeMembers() keys.PublicKeys {
var cvs = n.committee.Load().(keysWithVotes)
var committee = make(keys.PublicKeys, len(cvs))
var err error
for i := range committee {
committee[i], err = cvs[i].PublicKey()
if err != nil {
panic(err)
}
}
return committee
}
func toKeysWithVotes(pubs keys.PublicKeys) keysWithVotes {
ks := make(keysWithVotes, len(pubs))
for i := range pubs {
ks[i].UnmarshaledKey = pubs[i]
ks[i].Key = string(pubs[i].Bytes())
ks[i].Votes = big.NewInt(0)
}
return ks
}
// computeCommitteeMembers returns public keys of nodes in committee.
func (n *NEO) computeCommitteeMembers(bc blockchainer.Blockchainer, d dao.DAO) (keys.PublicKeys, keysWithVotes, error) {
key := []byte{prefixVotersCount}
si := d.GetStorageItem(n.ContractID, key)
if si == nil {
return nil, nil, errors.New("voters count not found")
}
votersCount := bigint.FromBytes(si.Value)
// votersCount / totalSupply must be >= 0.2
votersCount.Mul(votersCount, big.NewInt(effectiveVoterTurnout))
voterTurnout := votersCount.Div(votersCount, n.getTotalSupply(d))
sbVals := bc.GetStandByCommittee()
count := len(sbVals)
cs, err := n.getCandidates(d, false)
if err != nil {
return nil, nil, err
}
if voterTurnout.Sign() != 1 || len(cs) < count {
kvs := make(keysWithVotes, count)
for i := range kvs {
kvs[i].UnmarshaledKey = sbVals[i]
kvs[i].Key = string(sbVals[i].Bytes())
votes := big.NewInt(0)
for j := range cs {
if cs[j].Key == kvs[i].Key {
votes = cs[j].Votes
break
}
}
kvs[i].Votes = votes
}
return sbVals, kvs, nil
}
pubs := make(keys.PublicKeys, count)
for i := range pubs {
pubs[i], err = cs[i].PublicKey()
if err != nil {
return nil, nil, err
}
}
return pubs, cs[:count], nil
}
func (n *NEO) getNextBlockValidators(ic *interop.Context, _ []stackitem.Item) stackitem.Item {
result := n.GetNextBlockValidatorsInternal()
return pubsToArray(result)
}
// GetNextBlockValidatorsInternal returns next block validators.
func (n *NEO) GetNextBlockValidatorsInternal() keys.PublicKeys {
return n.nextValidators.Load().(keys.PublicKeys).Copy()
}
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
}
// putGASRecord is a helper which creates key and puts GASPerBlock value into the storage.
func (n *NEO) putGASRecord(dao dao.DAO, index uint32, value *big.Int) error {
key := make([]byte, 5)
key[0] = prefixGASPerBlock
binary.BigEndian.PutUint32(key[1:], index)
si := &state.StorageItem{
Value: bigint.ToBytes(value),
IsConst: false,
}
return dao.PutStorageItem(n.ContractID, key, si)
}