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("getŠ”ommittee", 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) checkCommittee(ic *interop.Context) bool { ok, err := runtime.CheckHashedWitness(ic, n.GetCommitteeAddress()) if err != nil { panic(err) } return ok } 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) }