Merge pull request #1518 from nspcc-dev/fix/economy

Distribute GAS to voters

cli/wallet_test.go

@@ -172,21 +172,48 @@ func TestClaimGas(t *testing.T) {
 	e := newExecutor(t, true)
 	defer e.Close(t)
 
-	start := e.Chain.BlockHeight()
+	const walletPath = "testdata/testwallet.json"
-	balanceBefore := e.Chain.GetUtilityTokenBalance(validatorHash)
+	w, err := wallet.NewWalletFromFile(walletPath)
+	require.NoError(t, err)
+	defer w.Close()
+
+	args := []string{
+		"neo-go", "wallet", "nep5", "multitransfer",
+		"--rpc-endpoint", "http://" + e.RPC.Addr,
+		"--wallet", validatorWallet,
+		"--from", validatorAddr,
+		"neo:" + w.Accounts[0].Address + ":1000",
+		"gas:" + w.Accounts[0].Address + ":1000", // for tx send
+	}
 	e.In.WriteString("one\r")
+	e.Run(t, args...)
+	e.checkTxPersisted(t)
+
+	h, err := address.StringToUint160(w.Accounts[0].Address)
+	require.NoError(t, err)
+
+	balanceBefore := e.Chain.GetUtilityTokenBalance(h)
+	claimHeight := e.Chain.BlockHeight() + 1
+	cl, err := e.Chain.CalculateClaimable(h, claimHeight)
+	require.NoError(t, err)
+	require.True(t, cl.Sign() > 0)
+
+	e.In.WriteString("testpass\r")
 	e.Run(t, "neo-go", "wallet", "claim",
 		"--rpc-endpoint", "http://"+e.RPC.Addr,
-		"--wallet", validatorWallet,
+		"--wallet", walletPath,
-		"--address", validatorAddr)
+		"--address", w.Accounts[0].Address)
-	tx, end := e.checkTxPersisted(t)
+	tx, height := e.checkTxPersisted(t)
-	b, _ := e.Chain.GetGoverningTokenBalance(validatorHash)
+	balanceBefore.Sub(balanceBefore, big.NewInt(tx.NetworkFee+tx.SystemFee))
-	cl := e.Chain.CalculateClaimable(b, start, end)
+	balanceBefore.Add(balanceBefore, cl)
-	require.True(t, cl.Sign() > 0)
-	cl.Sub(cl, big.NewInt(tx.NetworkFee+tx.SystemFee))
 
-	balanceAfter := e.Chain.GetUtilityTokenBalance(validatorHash)
+	balanceAfter := e.Chain.GetUtilityTokenBalance(h)
-	require.Equal(t, 0, balanceAfter.Cmp(balanceBefore.Add(balanceBefore, cl)))
+	// height can be bigger than claimHeight especially when tests are executed with -race.
+	if height == claimHeight {
+		require.Equal(t, 0, balanceAfter.Cmp(balanceBefore))
+	} else {
+		require.Equal(t, 1, balanceAfter.Cmp(balanceBefore))
+	}
 }
 
 func TestImportDeployed(t *testing.T) {

pkg/core/blockchain.go

@@ -1156,10 +1156,8 @@ func (bc *Blockchain) UnsubscribeFromExecutions(ch chan<- *state.AppExecResult)
 
 // CalculateClaimable calculates the amount of GAS generated by owning specified
 // amount of NEO between specified blocks.
-func (bc *Blockchain) CalculateClaimable(value *big.Int, startHeight, endHeight uint32) *big.Int {
+func (bc *Blockchain) CalculateClaimable(acc util.Uint160, endHeight uint32) (*big.Int, error) {
-	ic := bc.newInteropContext(trigger.Application, bc.dao, nil, nil)
+	return bc.contracts.NEO.CalculateBonus(bc.dao, acc, endHeight)
-	res, _ := bc.contracts.NEO.CalculateBonus(ic, value, startHeight, endHeight)
-	return res
 }
 
 // FeePerByte returns transaction network fee per byte.

pkg/core/blockchain_test.go

@@ -854,8 +854,9 @@ func TestGetClaimable(t *testing.T) {
 	require.NoError(t, err)
 
 	t.Run("first generation period", func(t *testing.T) {
-		amount := bc.CalculateClaimable(big.NewInt(1), 0, 2)
+		amount, err := bc.CalculateClaimable(neoOwner, 1)
-		require.EqualValues(t, big.NewInt(1), amount)
+		require.NoError(t, err)
+		require.EqualValues(t, big.NewInt(5*native.GASFactor/10), amount)
 	})
 }
 

pkg/core/blockchainer/blockchainer.go

@@ -22,7 +22,7 @@ type Blockchainer interface {
 	AddHeaders(...*block.Header) error
 	AddBlock(*block.Block) error
 	AddStateRoot(r *state.MPTRoot) error
-	CalculateClaimable(value *big.Int, startHeight, endHeight uint32) *big.Int
+	CalculateClaimable(h util.Uint160, endHeight uint32) (*big.Int, error)
 	Close()
 	HeaderHeight() uint32
 	GetBlock(hash util.Uint256) (*block.Block, error)

pkg/core/dao/dao.go

@@ -61,6 +61,7 @@ type DAO interface {
 	PutNEP5TransferLog(acc util.Uint160, index uint32, lg *state.NEP5TransferLog) error
 	PutStorageItem(id int32, key []byte, si *state.StorageItem) error
 	PutVersion(v string) error
+	Seek(id int32, prefix []byte, f func(k, v []byte))
 	StoreAsBlock(block *block.Block, buf *io.BufBinWriter) error
 	StoreAsCurrentBlock(block *block.Block, buf *io.BufBinWriter) error
 	StoreAsTransaction(tx *transaction.Transaction, index uint32, buf *io.BufBinWriter) error
@@ -406,10 +407,6 @@ func (dao *Simple) GetStorageItemsWithPrefix(id int32, prefix []byte) (map[strin
 	var siMap = make(map[string]*state.StorageItem)
 	var err error
 
-	lookupKey := makeStorageItemKey(id, nil)
-	if prefix != nil {
-		lookupKey = append(lookupKey, prefix...)
-	}
 	saveToMap := func(k, v []byte) {
 		if err != nil {
 			return
@@ -421,20 +418,28 @@ func (dao *Simple) GetStorageItemsWithPrefix(id int32, prefix []byte) (map[strin
 			err = r.Err
 			return
 		}
-
 		// Cut prefix and hash.
 		// Must copy here, #1468.
-		key := make([]byte, len(k[len(lookupKey):]))
+		key := make([]byte, len(k))
-		copy(key, k[len(lookupKey):])
+		copy(key, k)
 		siMap[string(key)] = si
 	}
-	dao.Store.Seek(lookupKey, saveToMap)
+	dao.Seek(id, prefix, saveToMap)
-	if err != nil {
-		return nil, err
-	}
 	return siMap, nil
 }
 
+// Seek executes f for all items with a given prefix.
+// If key is to be used outside of f, they must be copied.
+func (dao *Simple) Seek(id int32, prefix []byte, f func(k, v []byte)) {
+	lookupKey := makeStorageItemKey(id, nil)
+	if prefix != nil {
+		lookupKey = append(lookupKey, prefix...)
+	}
+	dao.Store.Seek(lookupKey, func(k, v []byte) {
+		f(k[len(lookupKey):], v)
+	})
+}
+
 // makeStorageItemKey returns a key used to store StorageItem in the DB.
 func makeStorageItemKey(id int32, key []byte) []byte {
 	// 1 for prefix + 4 for Uint32 + len(key) for key

pkg/core/helper_test.go

@@ -178,7 +178,7 @@ func TestCreateBasicChain(t *testing.T) {
 	priv0 := testchain.PrivateKeyByID(0)
 	priv0ScriptHash := priv0.GetScriptHash()
 
-	require.Equal(t, big.NewInt(2500_0000), bc.GetUtilityTokenBalance(priv0ScriptHash)) // gas bounty
+	require.Equal(t, big.NewInt(5000_0000), bc.GetUtilityTokenBalance(priv0ScriptHash)) // gas bounty
 	// Move some NEO to one simple account.
 	txMoveNeo := newNEP5Transfer(neoHash, neoOwner, priv0ScriptHash, neoAmount)
 	txMoveNeo.ValidUntilBlock = validUntilBlock

pkg/core/native/gas_record.go

@@ -1,13 +0,0 @@
-package native
-
-import "math/big"
-
-// gasIndexPair contains block index together with generated gas per block.
-// It is used to cache NEO GASRecords.
-type gasIndexPair struct {
-	Index       uint32
-	GASPerBlock big.Int
-}
-
-// gasRecord contains history of gas per block changes. It is used only by NEO cache.
-type gasRecord []gasIndexPair

pkg/core/native/native_neo.go

@@ -15,6 +15,7 @@ import (
 	"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/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"
@@ -37,8 +38,8 @@ type NEO struct {
 	votesChanged   atomic.Value
 	nextValidators atomic.Value
 	validators     atomic.Value
-	// committee contains cached committee members and
+	// committee contains cached committee members and their votes.
-	// is updated once in a while depending on committee size
+	// 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
@@ -46,14 +47,6 @@ type NEO struct {
 	committeeHash 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
@@ -63,6 +56,11 @@ const (
 	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
@@ -71,9 +69,9 @@ const (
 	// 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 = 5
+	committeeRewardRatio = 10
 	// neoHolderRewardRatio is a percent of generated GAS that is distributed to voters.
-	voterRewardRatio = 85
+	voterRewardRatio = 80
 )
 
 var (
@@ -107,7 +105,7 @@ func newNEO() *NEO {
 	n.votesChanged.Store(true)
 	n.nextValidators.Store(keys.PublicKeys(nil))
 	n.validators.Store(keys.PublicKeys(nil))
-	n.committee.Store(keys.PublicKeys(nil))
+	n.committee.Store(keysWithVotes(nil))
 	n.committeeHash.Store(util.Uint160{})
 
 	onp := n.Methods["onPersist"]
@@ -175,12 +173,13 @@ func (n *NEO) Initialize(ic *interop.Context) error {
 	}
 
 	committee := ic.Chain.GetStandByCommittee()
-	err := n.updateCache(committee, ic.Chain)
+	cvs := toKeysWithVotes(committee)
+	err := n.updateCache(cvs, ic.Chain)
 	if err != nil {
 		return err
 	}
 
-	err = ic.DAO.PutStorageItem(n.ContractID, prefixCommittee, &state.StorageItem{Value: committee.Bytes()})
+	err = ic.DAO.PutStorageItem(n.ContractID, prefixCommittee, &state.StorageItem{Value: cvs.Bytes()})
 	if err != nil {
 		return err
 	}
@@ -212,7 +211,7 @@ func (n *NEO) Initialize(ic *interop.Context) error {
 // 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 {
-	committee := keys.PublicKeys{}
+	var committee = keysWithVotes{}
 	si := d.GetStorageItem(n.ContractID, prefixCommittee)
 	if err := committee.DecodeBytes(si.Value); err != nil {
 		return err
@@ -231,8 +230,10 @@ func (n *NEO) InitializeCache(bc blockchainer.Blockchainer, d dao.DAO) error {
 	return nil
 }
 
-func (n *NEO) updateCache(committee keys.PublicKeys, bc blockchainer.Blockchainer) error {
+func (n *NEO) updateCache(cvs keysWithVotes, bc blockchainer.Blockchainer) error {
-	n.committee.Store(committee)
+	n.committee.Store(cvs)
+
+	var committee = n.GetCommitteeMembers()
 	script, err := smartcontract.CreateMajorityMultiSigRedeemScript(committee.Copy())
 	if err != nil {
 		return err
@@ -249,20 +250,22 @@ 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().(keys.PublicKeys)
+		committee := n.committee.Load().(keysWithVotes)
 		si := &state.StorageItem{Value: committee.Bytes()}
 		return ic.DAO.PutStorageItem(n.ContractID, prefixCommittee, si)
 	}
 
-	committee, err := n.ComputeCommitteeMembers(ic.Chain, ic.DAO)
+	committee, cvs, err := n.computeCommitteeMembers(ic.Chain, ic.DAO)
 	if err != nil {
 		return err
+	} else if cvs == nil {
+		cvs = toKeysWithVotes(committee)
 	}
-	if err := n.updateCache(committee, ic.Chain); err != nil {
+	if err := n.updateCache(cvs, ic.Chain); err != nil {
 		return err
 	}
 	n.votesChanged.Store(false)
-	si := &state.StorageItem{Value: committee.Bytes()}
+	si := &state.StorageItem{Value: cvs.Bytes()}
 	return ic.DAO.PutStorageItem(n.ContractID, prefixCommittee, si)
 }
 
@@ -287,13 +290,66 @@ func (n *NEO) OnPersist(ic *interop.Context) error {
 func (n *NEO) PostPersist(ic *interop.Context) error {
 	gas := n.GetGASPerBlock(ic.DAO, ic.Block.Index)
 	pubs := n.GetCommitteeMembers()
-	index := int(ic.Block.Index) % len(ic.Chain.GetConfig().StandbyCommittee)
+	committeeSize := len(ic.Chain.GetConfig().StandbyCommittee)
-	gas.Mul(gas, big.NewInt(committeeRewardRatio))
+	index := int(ic.Block.Index) % committeeSize
-	n.GAS.mint(ic, pubs[index].GetScriptHash(), gas.Div(gas, big.NewInt(100)))
+	committeeReward := new(big.Int).Mul(gas, big.NewInt(committeeRewardRatio))
+	n.GAS.mint(ic, pubs[index].GetScriptHash(), committeeReward.Div(committeeReward, big.NewInt(100)))
+
+	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
+				}
+			}
+		}
+
+	}
 	n.OnPersistEnd(ic.DAO)
 	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))
+	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
+					reward[i] = *bigint.FromBytes(v)
+				}
+			}
+		}
+	})
+	return reward
+}
+
 // OnPersistEnd updates cached values if they've been changed.
 func (n *NEO) OnPersistEnd(d dao.DAO) {
 	if n.gasPerBlockChanged.Load().(bool) {
@@ -342,7 +398,7 @@ func (n *NEO) distributeGas(ic *interop.Context, h util.Uint160, acc *state.NEOB
 	if ic.Block == nil || ic.Block.Index == 0 {
 		return nil
 	}
-	gen, err := n.CalculateBonus(ic, &acc.Balance, acc.BalanceHeight, ic.Block.Index)
+	gen, err := n.calculateBonus(ic.DAO, acc.VoteTo, &acc.Balance, acc.BalanceHeight, ic.Block.Index)
 	if err != nil {
 		return err
 	}
@@ -354,13 +410,7 @@ func (n *NEO) distributeGas(ic *interop.Context, h util.Uint160, acc *state.NEOB
 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)
+	gen, err := n.CalculateBonus(ic.DAO, u, end)
-	if err != nil {
-		panic(err)
-	}
-	tr := bs.Trackers[n.ContractID]
-
-	gen, err := n.CalculateBonus(ic, &tr.Balance, tr.LastUpdatedBlock, end)
 	if err != nil {
 		panic(err)
 	}
@@ -445,8 +495,70 @@ func (n *NEO) SetGASPerBlock(ic *interop.Context, index uint32, gas *big.Int) (b
 	return true, n.putGASRecord(ic.DAO, index, gas)
 }
 
-// CalculateBonus calculates amount of gas generated for holding `value` NEO from start to end block.
+func (n *NEO) dropCandidateIfZero(d dao.DAO, pub *keys.PublicKey, c *candidate) (bool, error) {
-func (n *NEO) CalculateBonus(ic *interop.Context, value *big.Int, start, end uint32) (*big.Int, 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 {
@@ -459,7 +571,7 @@ func (n *NEO) CalculateBonus(ic *interop.Context, value *big.Int, start, end uin
 	if !n.gasPerBlockChanged.Load().(bool) {
 		gr = n.gasPerBlock.Load().(gasRecord)
 	} else {
-		gr, err = n.getSortedGASRecordFromDAO(ic.DAO)
+		gr, err = n.getSortedGASRecordFromDAO(d)
 		if err != nil {
 			return nil, err
 		}
@@ -533,10 +645,11 @@ func (n *NEO) UnregisterCandidateInternal(ic *interop.Context, pub *keys.PublicK
 	}
 	n.validators.Store(keys.PublicKeys(nil))
 	c := new(candidate).FromBytes(si.Value)
-	if c.Votes.Sign() == 0 {
-		return ic.DAO.DeleteStorageItem(n.ContractID, key)
-	}
 	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)
 }
@@ -577,6 +690,9 @@ func (n *NEO) VoteInternal(ic *interop.Context, h util.Uint160, pub *keys.Public
 			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
 	}
@@ -601,8 +717,9 @@ func (n *NEO) ModifyAccountVotes(acc *state.NEOBalanceState, d dao.DAO, value *b
 		cd := new(candidate).FromBytes(si.Value)
 		cd.Votes.Add(&cd.Votes, value)
 		if !isNewVote {
-			if !cd.Registered && cd.Votes.Sign() == 0 {
+			ok, err := n.dropCandidateIfZero(d, acc.VoteTo, cd)
-				return d.DeleteStorageItem(n.ContractID, key)
+			if ok {
+				return err
 			}
 		} else if !cd.Registered {
 			return errors.New("validator must be registered")
@@ -614,7 +731,7 @@ func (n *NEO) ModifyAccountVotes(acc *state.NEOBalanceState, d dao.DAO, value *b
 	return nil
 }
 
-func (n *NEO) getCandidates(d dao.DAO) ([]keyWithVotes, error) {
+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
@@ -623,17 +740,29 @@ func (n *NEO) getCandidates(d dao.DAO) ([]keyWithVotes, error) {
 	for key, si := range siMap {
 		c := new(candidate).FromBytes(si.Value)
 		if c.Registered {
-			arr = append(arr, keyWithVotes{key, &c.Votes})
+			arr = append(arr, keyWithVotes{Key: key, Votes: &c.Votes})
 		}
 	}
-	sort.Slice(arr, func(i, j int) bool { return strings.Compare(arr[i].Key, arr[j].Key) == -1 })
+	if sortByKey {
+		sort.Slice(arr, func(i, j int) bool { return strings.Compare(arr[i].Key, arr[j].Key) == -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, arr[j].Key) == -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)
+	kvs, err := n.getCandidates(d, true)
 	if err != nil {
 		return nil, err
 	}
@@ -649,7 +778,7 @@ func (n *NEO) GetCandidates(d dao.DAO) ([]state.Validator, error) {
 }
 
 func (n *NEO) getCandidatesCall(ic *interop.Context, _ []stackitem.Item) stackitem.Item {
-	validators, err := n.getCandidates(ic.DAO)
+	validators, err := n.getCandidates(ic.DAO, true)
 	if err != nil {
 		panic(err)
 	}
@@ -668,7 +797,7 @@ func (n *NEO) ComputeNextBlockValidators(bc blockchainer.Blockchainer, d dao.DAO
 	if vals := n.validators.Load().(keys.PublicKeys); vals != nil {
 		return vals.Copy(), nil
 	}
-	result, err := n.ComputeCommitteeMembers(bc, d)
+	result, _, err := n.computeCommitteeMembers(bc, d)
 	if err != nil {
 		return nil, err
 	}
@@ -698,15 +827,34 @@ func (n *NEO) modifyVoterTurnout(d dao.DAO, amount *big.Int) error {
 
 // GetCommitteeMembers returns public keys of nodes in committee using cached value.
 func (n *NEO) GetCommitteeMembers() keys.PublicKeys {
-	return n.committee.Load().(keys.PublicKeys).Copy()
+	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
 }
 
-// ComputeCommitteeMembers returns public keys of nodes in committee.
+func toKeysWithVotes(pubs keys.PublicKeys) keysWithVotes {
-func (n *NEO) ComputeCommitteeMembers(bc blockchainer.Blockchainer, d dao.DAO) (keys.PublicKeys, error) {
+	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, errors.New("voters count not found")
+		return nil, nil, errors.New("voters count not found")
 	}
 	votersCount := bigint.FromBytes(si.Value)
 	// votersCount / totalSupply must be >= 0.2
@@ -714,34 +862,25 @@ func (n *NEO) ComputeCommitteeMembers(bc blockchainer.Blockchainer, d dao.DAO) (
 	voterTurnout := votersCount.Div(votersCount, n.getTotalSupply(d))
 	if voterTurnout.Sign() != 1 {
 		pubs := bc.GetStandByCommittee()
-		return pubs, nil
+		return pubs, nil, nil
 	}
-	cs, err := n.getCandidates(d)
+	cs, err := n.getCandidates(d, false)
 	if err != nil {
-		return nil, err
+		return nil, nil, err
 	}
 	sbVals := bc.GetStandByCommittee()
 	count := len(sbVals)
 	if len(cs) < count {
-		return sbVals, nil
+		return sbVals, nil, nil
 	}
-	sort.Slice(cs, func(i, j int) bool {
-		// The most-voted validators should end up in the front of the list.
-		cmp := cs[i].Votes.Cmp(cs[j].Votes)
-		if cmp != 0 {
-			return cmp > 0
-		}
-		// Ties are broken with public keys.
-		return strings.Compare(cs[i].Key, cs[j].Key) == -1
-	})
 	pubs := make(keys.PublicKeys, count)
 	for i := range pubs {
-		pubs[i], err = keys.NewPublicKeyFromBytes([]byte(cs[i].Key), elliptic.P256())
+		pubs[i], err = cs[i].PublicKey()
 		if err != nil {
-			return nil, err
+			return nil, nil, err
 		}
 	}
-	return pubs, nil
+	return pubs, cs[:count], nil
 }
 
 func (n *NEO) getNextBlockValidators(ic *interop.Context, _ []stackitem.Item) stackitem.Item {

pkg/core/native/neo_types.go

@@ -0,0 +1,104 @@
+package native
+
+import (
+	"crypto/elliptic"
+	"errors"
+	"math/big"
+
+	"github.com/nspcc-dev/neo-go/pkg/crypto/keys"
+	"github.com/nspcc-dev/neo-go/pkg/io"
+	"github.com/nspcc-dev/neo-go/pkg/vm/stackitem"
+)
+
+// gasIndexPair contains block index together with generated gas per block.
+// It is used to cache NEO GASRecords.
+type gasIndexPair struct {
+	Index       uint32
+	GASPerBlock big.Int
+}
+
+// gasRecord contains history of gas per block changes. It is used only by NEO cache.
+type gasRecord []gasIndexPair
+
+type (
+	// 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.
+	keyWithVotes struct {
+		Key   string
+		Votes *big.Int
+		// UnmarshaledKey contains public key if it was unmarshaled.
+		UnmarshaledKey *keys.PublicKey
+	}
+
+	keysWithVotes []keyWithVotes
+)
+
+// PublicKey unmarshals and returns public key of k.
+func (k keyWithVotes) PublicKey() (*keys.PublicKey, error) {
+	if k.UnmarshaledKey != nil {
+		return k.UnmarshaledKey, nil
+	}
+	return keys.NewPublicKeyFromBytes([]byte(k.Key), elliptic.P256())
+}
+
+func (k keysWithVotes) toStackItem() stackitem.Item {
+	arr := make([]stackitem.Item, len(k))
+	for i := range k {
+		arr[i] = stackitem.NewStruct([]stackitem.Item{
+			stackitem.NewByteArray([]byte(k[i].Key)),
+			stackitem.NewBigInteger(k[i].Votes),
+		})
+	}
+	return stackitem.NewArray(arr)
+}
+
+func (k *keysWithVotes) fromStackItem(item stackitem.Item) error {
+	arr, ok := item.Value().([]stackitem.Item)
+	if !ok {
+		return errors.New("not an array")
+	}
+
+	var kvs = make(keysWithVotes, len(arr))
+	for i := range arr {
+		s, ok := arr[i].Value().([]stackitem.Item)
+		if !ok {
+			return errors.New("element is not a struct")
+		} else if len(s) < 2 {
+			return errors.New("invalid length")
+		}
+		pub, err := s[0].TryBytes()
+		if err != nil {
+			return err
+		}
+		vs, err := s[1].TryInteger()
+		if err != nil {
+			return err
+		}
+		kvs[i].Key = string(pub)
+		kvs[i].Votes = vs
+	}
+	*k = kvs
+	return nil
+}
+
+// Bytes serializes keys with votes slice.
+func (k keysWithVotes) Bytes() []byte {
+	var it = k.toStackItem()
+	var w = io.NewBufBinWriter()
+	stackitem.EncodeBinaryStackItem(it, w.BinWriter)
+	if w.Err != nil {
+		panic(w.Err)
+	}
+	return w.Bytes()
+}
+
+// DecodeBytes deserializes keys and votes slice.
+func (k *keysWithVotes) DecodeBytes(data []byte) error {
+	var r = io.NewBinReaderFromBuf(data)
+	var it = stackitem.DecodeBinaryStackItem(r)
+	if r.Err != nil {
+		return r.Err
+	}
+	return k.fromStackItem(it)
+}

pkg/core/native_neo_test.go

@@ -10,10 +10,13 @@ import (
 	"github.com/nspcc-dev/neo-go/pkg/core/transaction"
 	"github.com/nspcc-dev/neo-go/pkg/crypto/keys"
 	"github.com/nspcc-dev/neo-go/pkg/internal/testchain"
-	"github.com/nspcc-dev/neo-go/pkg/smartcontract"
+	"github.com/nspcc-dev/neo-go/pkg/io"
 	"github.com/nspcc-dev/neo-go/pkg/smartcontract/trigger"
 	"github.com/nspcc-dev/neo-go/pkg/util"
+	"github.com/nspcc-dev/neo-go/pkg/vm"
+	"github.com/nspcc-dev/neo-go/pkg/vm/emit"
 	"github.com/nspcc-dev/neo-go/pkg/vm/opcode"
+	"github.com/nspcc-dev/neo-go/pkg/wallet"
 	"github.com/stretchr/testify/require"
 )
 
@@ -24,6 +27,12 @@ func setSigner(tx *transaction.Transaction, h util.Uint160) {
 	}}
 }
 
+func checkTxHalt(t *testing.T, bc *Blockchain, h util.Uint256) {
+	aer, err := bc.GetAppExecResult(h)
+	require.NoError(t, err)
+	require.Equal(t, vm.HaltState, aer.VMState, aer.FaultException)
+}
+
 func TestNEO_Vote(t *testing.T) {
 	bc := newTestChain(t)
 	defer bc.Close()
@@ -37,7 +46,7 @@ func TestNEO_Vote(t *testing.T) {
 	freq := testchain.ValidatorsCount + testchain.CommitteeSize()
 	advanceChain := func(t *testing.T) {
 		for i := 0; i < freq; i++ {
-			require.NoError(t, neo.OnPersist(ic))
+			require.NoError(t, bc.AddBlock(bc.newBlock()))
 			ic.Block.Index++
 		}
 	}
@@ -48,27 +57,45 @@ func TestNEO_Vote(t *testing.T) {
 	require.NoError(t, err)
 	require.Equal(t, standBySorted, pubs)
 
-	sz := testchain.Size()
+	sz := testchain.CommitteeSize()
-
+	accs := make([]*wallet.Account, sz)
 	candidates := make(keys.PublicKeys, sz)
+	txs := make([]*transaction.Transaction, 0, len(accs))
 	for i := 0; i < sz; i++ {
 		priv, err := keys.NewPrivateKey()
 		require.NoError(t, err)
 		candidates[i] = priv.PublicKey()
+		accs[i], err = wallet.NewAccount()
+		require.NoError(t, err)
 		if i > 0 {
 			require.NoError(t, neo.RegisterCandidateInternal(ic, candidates[i]))
 		}
-	}
 
-	for i := 0; i < sz; i++ {
+		to := accs[i].Contract.ScriptHash()
-		to := testchain.PrivateKeyByID(i).GetScriptHash()
+		w := io.NewBufBinWriter()
-		ic.VM.Load(testchain.MultisigVerificationScript())
+		emit.AppCallWithOperationAndArgs(w.BinWriter, bc.contracts.NEO.Hash, "transfer",
-		ic.VM.LoadScriptWithHash(testchain.MultisigVerificationScript(), testchain.MultisigScriptHash(), smartcontract.All)
+			neoOwner.BytesBE(), to.BytesBE(),
-		require.NoError(t, neo.TransferInternal(ic, testchain.MultisigScriptHash(), to, big.NewInt(int64(sz-i)*10000000)))
+			big.NewInt(int64(sz-i)*1000000).Int64())
+		emit.Opcodes(w.BinWriter, opcode.ASSERT)
+		emit.AppCallWithOperationAndArgs(w.BinWriter, bc.contracts.GAS.Hash, "transfer",
+			neoOwner.BytesBE(), to.BytesBE(),
+			int64(1_000_000_000))
+		emit.Opcodes(w.BinWriter, opcode.ASSERT)
+		require.NoError(t, w.Err)
+		tx := transaction.New(netmode.UnitTestNet, w.Bytes(), 1000_000_000)
+		tx.ValidUntilBlock = bc.BlockHeight() + 1
+		setSigner(tx, testchain.MultisigScriptHash())
+		require.NoError(t, signTx(bc, tx))
+		txs = append(txs, tx)
 	}
+	require.NoError(t, bc.AddBlock(bc.newBlock(txs...)))
+	for _, tx := range txs {
+		checkTxHalt(t, bc, tx.Hash())
+	}
+	transferBlock := bc.BlockHeight()
 
 	for i := 1; i < sz; i++ {
-		priv := testchain.PrivateKeyByID(i)
+		priv := accs[i].PrivateKey()
 		h := priv.GetScriptHash()
 		setSigner(tx, h)
 		ic.VM.Load(priv.PublicKey().GetVerificationScript())
@@ -86,27 +113,72 @@ func TestNEO_Vote(t *testing.T) {
 
 	// Register and give some value to the last validator.
 	require.NoError(t, neo.RegisterCandidateInternal(ic, candidates[0]))
-	priv := testchain.PrivateKeyByID(0)
+	priv := accs[0].PrivateKey()
 	h := priv.GetScriptHash()
 	setSigner(tx, h)
 	ic.VM.Load(priv.PublicKey().GetVerificationScript())
 	require.NoError(t, neo.VoteInternal(ic, h, candidates[0]))
 
-	for i := testchain.ValidatorsCount; i < testchain.CommitteeSize(); i++ {
+	ic.DAO.Persist()
-		priv := testchain.PrivateKey(i)
-		require.NoError(t, neo.RegisterCandidateInternal(ic, priv.PublicKey()))
-	}
-
 	advanceChain(t)
 	pubs, err = neo.ComputeNextBlockValidators(bc, ic.DAO)
 	require.NoError(t, err)
-	sortedCandidates := candidates.Copy()
+	sortedCandidates := candidates.Copy()[:testchain.Size()]
 	sort.Sort(sortedCandidates)
 	require.EqualValues(t, sortedCandidates, pubs)
 
 	pubs = neo.GetNextBlockValidatorsInternal()
 	require.EqualValues(t, sortedCandidates, pubs)
 
+	t.Run("check voter rewards", func(t *testing.T) {
+		gasBalance := make([]*big.Int, len(accs))
+		neoBalance := make([]*big.Int, len(accs))
+		txs := make([]*transaction.Transaction, 0, len(accs))
+		for i := range accs {
+			w := io.NewBufBinWriter()
+			h := accs[i].PrivateKey().GetScriptHash()
+			gasBalance[i] = bc.GetUtilityTokenBalance(h)
+			neoBalance[i], _ = bc.GetGoverningTokenBalance(h)
+			emit.AppCallWithOperationAndArgs(w.BinWriter, bc.contracts.NEO.Hash, "transfer",
+				h.BytesBE(), h.BytesBE(), int64(1))
+			emit.Opcodes(w.BinWriter, opcode.ASSERT)
+			require.NoError(t, w.Err)
+			tx := transaction.New(netmode.UnitTestNet, w.Bytes(), 0)
+			tx.ValidUntilBlock = bc.BlockHeight() + 1
+			tx.NetworkFee = 2_000_000
+			tx.SystemFee = 10_000_000
+			setSigner(tx, h)
+			require.NoError(t, accs[i].SignTx(tx))
+			txs = append(txs, tx)
+		}
+		require.NoError(t, bc.AddBlock(bc.newBlock(txs...)))
+		for _, tx := range txs {
+			checkTxHalt(t, bc, tx.Hash())
+		}
+
+		// GAS increase consists of 2 parts: NEO holding + voting for committee nodes.
+		// Here we check that 2-nd part exists and is proportional to the amount of NEO given.
+		for i := range accs {
+			newGAS := bc.GetUtilityTokenBalance(accs[i].Contract.ScriptHash())
+			newGAS.Sub(newGAS, gasBalance[i])
+
+			gasForHold, err := bc.contracts.NEO.CalculateNEOHolderReward(bc.dao, neoBalance[i], transferBlock, bc.BlockHeight())
+			require.NoError(t, err)
+			newGAS.Sub(newGAS, gasForHold)
+			require.True(t, newGAS.Sign() > 0)
+			gasBalance[i] = newGAS
+		}
+		// First account voted later than the others.
+		require.Equal(t, -1, gasBalance[0].Cmp(gasBalance[1]))
+		for i := 2; i < testchain.ValidatorsCount; i++ {
+			require.Equal(t, 0, gasBalance[i].Cmp(gasBalance[1]))
+		}
+		require.Equal(t, 1, gasBalance[1].Cmp(gasBalance[testchain.ValidatorsCount]))
+		for i := testchain.ValidatorsCount; i < testchain.CommitteeSize(); i++ {
+			require.Equal(t, 0, gasBalance[i].Cmp(gasBalance[testchain.ValidatorsCount]))
+		}
+	})
+
 	require.NoError(t, neo.UnregisterCandidateInternal(ic, candidates[0]))
 	require.Error(t, neo.VoteInternal(ic, h, candidates[0]))
 	advanceChain(t)
@@ -187,11 +259,11 @@ func TestNEO_CalculateBonus(t *testing.T) {
 	ic.SpawnVM()
 	ic.VM.LoadScript([]byte{byte(opcode.RET)})
 	t.Run("Invalid", func(t *testing.T) {
-		_, err := neo.CalculateBonus(ic, new(big.Int).SetInt64(-1), 0, 1)
+		_, err := neo.CalculateNEOHolderReward(ic.DAO, new(big.Int).SetInt64(-1), 0, 1)
 		require.Error(t, err)
 	})
 	t.Run("Zero", func(t *testing.T) {
-		res, err := neo.CalculateBonus(ic, big.NewInt(0), 0, 100)
+		res, err := neo.CalculateNEOHolderReward(ic.DAO, big.NewInt(0), 0, 100)
 		require.NoError(t, err)
 		require.EqualValues(t, 0, res.Int64())
 	})
@@ -201,7 +273,7 @@ func TestNEO_CalculateBonus(t *testing.T) {
 		require.NoError(t, err)
 		require.True(t, ok)
 
-		res, err := neo.CalculateBonus(ic, big.NewInt(100), 5, 15)
+		res, err := neo.CalculateNEOHolderReward(ic.DAO, big.NewInt(100), 5, 15)
 		require.NoError(t, err)
 		require.EqualValues(t, (100*5*5/10)+(100*5*1/10), res.Int64())
 
@@ -217,7 +289,7 @@ func TestNEO_CommitteeBountyOnPersist(t *testing.T) {
 		hs[i] = testchain.PrivateKeyByID(i).GetScriptHash()
 	}
 
-	const singleBounty = 25000000
+	const singleBounty = 50000000
 	bs := map[int]int64{0: singleBounty}
 	checkBalances := func() {
 		for i := 0; i < testchain.CommitteeSize(); i++ {

pkg/network/helper_test.go

@@ -33,7 +33,7 @@ func (chain testChain) ApplyPolicyToTxSet([]*transaction.Transaction) []*transac
 func (chain testChain) GetConfig() config.ProtocolConfiguration {
 	panic("TODO")
 }
-func (chain testChain) CalculateClaimable(*big.Int, uint32, uint32) *big.Int {
+func (chain testChain) CalculateClaimable(util.Uint160, uint32) (*big.Int, error) {
 	panic("TODO")
 }
 

pkg/rpc/server/server.go

@@ -951,13 +951,16 @@ func (s *Server) getUnclaimedGas(ps request.Params) (interface{}, *response.Erro
 		return nil, response.ErrInvalidParams
 	}
 
-	neo, neoHeight := s.chain.GetGoverningTokenBalance(u)
+	neo, _ := s.chain.GetGoverningTokenBalance(u)
 	if neo.Sign() == 0 {
 		return result.UnclaimedGas{
 			Address: u,
 		}, nil
 	}
-	gas := s.chain.CalculateClaimable(neo, neoHeight, s.chain.BlockHeight()+1) // +1 as in C#, for the next block.
+	gas, err := s.chain.CalculateClaimable(u, s.chain.BlockHeight()+1) // +1 as in C#, for the next block.
+	if err != nil {
+		return nil, response.NewInternalServerError("can't calculate claimable", err)
+	}
 	return result.UnclaimedGas{
 		Address:   u,
 		Unclaimed: *gas,

pkg/rpc/server/server_test.go

@@ -1214,7 +1214,7 @@ func checkNep5Balances(t *testing.T, e *executor, acc interface{}) {
 			},
 			{
 				Asset:       e.chain.UtilityTokenHash(),
-				Amount:      "799.59641770",
+				Amount:      "800.09641770",
 				LastUpdated: 7,
 			}},
 		Address: testchain.PrivateKeyByID(0).GetScriptHash().StringLE(),
@@ -1361,7 +1361,7 @@ func checkNep5TransfersAux(t *testing.T, e *executor, acc interface{}, sent, rcv
 				Timestamp:   blockGASBounty.Timestamp,
 				Asset:       e.chain.UtilityTokenHash(),
 				Address:     "",
-				Amount:      "0.25000000",
+				Amount:      "0.50000000",
 				Index:       6,
 				NotifyIndex: 0,
 				TxHash:      blockGASBounty.Hash(),
@@ -1406,7 +1406,7 @@ func checkNep5TransfersAux(t *testing.T, e *executor, acc interface{}, sent, rcv
 				Timestamp: blockGASBounty0.Timestamp,
 				Asset:     e.chain.UtilityTokenHash(),
 				Address:   "",
-				Amount:    "0.25000000",
+				Amount:    "0.50000000",
 				Index:     0,
 				TxHash:    blockGASBounty0.Hash(),
 			},