native: optimize vote reward data (fix #2844)

ROADMAP.md

@@ -134,3 +134,10 @@ for security reasons.
 
 Removal of these options from ProtocolConfiguration is scheduled for May-June
 2023 (~0.103.0 release).
+
+## `NEOBalance` from stack item
+
+We check struct items count before convert LastGasPerVote to let RPC client be compatible with
+old versions.
+
+Removal of this compatiblility code is scheduled for Sep-Oct 2023. 

pkg/core/blockchain.go

@@ -2240,7 +2240,12 @@ unsubloop:
 // CalculateClaimable calculates the amount of GAS generated by owning specified
 // amount of NEO between specified blocks.
 func (bc *Blockchain) CalculateClaimable(acc util.Uint160, endHeight uint32) (*big.Int, error) {
-	return bc.contracts.NEO.CalculateBonus(bc.dao, acc, endHeight)
+	nextBlock, err := bc.getFakeNextBlock(bc.BlockHeight() + 1)
+	if err != nil {
+		return nil, err
+	}
+	ic := bc.newInteropContext(trigger.Application, bc.dao, nextBlock, nil)
+	return bc.contracts.NEO.CalculateBonus(ic, acc, endHeight)
 }
 
 // FeePerByte returns transaction network fee per byte.

pkg/core/native/native_neo.go

@@ -409,7 +409,7 @@ func (n *NEO) PostPersist(ic *interop.Context) error {
 		var (
 			cs        = cache.committee
 			isCacheRW bool
-			key       = make([]byte, 38)
+			key       = make([]byte, 34)
 		)
 		for i := range cs {
 			if cs[i].Votes.Sign() > 0 {
@@ -423,17 +423,9 @@ func (n *NEO) PostPersist(ic *interop.Context) error {
 				tmp.Div(tmp, cs[i].Votes)
 
 				key = makeVoterKey([]byte(cs[i].Key), key)
+				r := n.getLatestGASPerVote(ic.DAO, key)
+				tmp.Add(tmp, &r)
 
-				var r *big.Int
-				if g, ok := cache.gasPerVoteCache[cs[i].Key]; ok {
-					r = &g
-				} else {
-					reward := n.getGASPerVote(ic.DAO, key[:34], []uint32{ic.Block.Index + 1})
-					r = &reward[0]
-				}
-				tmp.Add(tmp, r)
-
-				binary.BigEndian.PutUint32(key[34:], ic.Block.Index+1)
 				if !isCacheRW {
 					cache = ic.DAO.GetRWCache(n.ID).(*NeoCache)
 					isCacheRW = true
@@ -447,33 +439,19 @@ func (n *NEO) PostPersist(ic *interop.Context) error {
 	return nil
 }
 
-func (n *NEO) getGASPerVote(d *dao.Simple, key []byte, indexes []uint32) []big.Int {
-	sort.Slice(indexes, func(i, j int) bool {
-		return indexes[i] < indexes[j]
-	})
-	start := make([]byte, 4)
-	binary.BigEndian.PutUint32(start, indexes[len(indexes)-1])
-
-	need := len(indexes)
-	var reward = make([]big.Int, need)
-	collected := 0
-	d.Seek(n.ID, storage.SeekRange{
-		Prefix:    key,
-		Start:     start,
-		Backwards: true,
-	}, func(k, v []byte) bool {
-		if len(k) == 4 {
-			num := binary.BigEndian.Uint32(k)
-			for i, ind := range indexes {
-				if reward[i].Sign() == 0 && num <= ind {
-					reward[i] = *bigint.FromBytes(v)
-					collected++
-				}
-			}
-		}
-		return collected < need
-	})
-	return reward
+func (n *NEO) getLatestGASPerVote(d *dao.Simple, key []byte) big.Int {
+	var g big.Int
+	cache := d.GetROCache(n.ID).(*NeoCache)
+	if g, ok := cache.gasPerVoteCache[string(key[1:])]; ok {
+		return g
+	}
+	item := d.GetStorageItem(n.ID, key)
+	if item == nil {
+		g = *big.NewInt(0)
+	} else {
+		g = *bigint.FromBytes(item)
+	}
+	return g
 }
 
 func (n *NEO) increaseBalance(ic *interop.Context, h util.Uint160, si *state.StorageItem, amount *big.Int, checkBal *big.Int) (func(), error) {
@@ -527,19 +505,23 @@ func (n *NEO) distributeGas(ic *interop.Context, acc *state.NEOBalance) (*big.In
 	if ic.Block == nil || ic.Block.Index == 0 || ic.Block.Index == acc.BalanceHeight {
 		return nil, nil
 	}
-	gen, err := n.calculateBonus(ic.DAO, acc.VoteTo, &acc.Balance, acc.BalanceHeight, ic.Block.Index)
+	gen, err := n.calculateBonus(ic.DAO, acc, ic.Block.Index)
 	if err != nil {
 		return nil, err
 	}
 	acc.BalanceHeight = ic.Block.Index
+	if acc.VoteTo != nil {
+		latestGasPerVote := n.getLatestGASPerVote(ic.DAO, makeVoterKey(acc.VoteTo.Bytes()))
+		acc.LastGasPerVote = latestGasPerVote
+	}
 
 	return gen, 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)
+	gen, err := n.CalculateBonus(ic, u, end)
 	if err != nil {
 		panic(err)
 	}
@@ -647,10 +629,7 @@ func (n *NEO) dropCandidateIfZero(d *dao.Simple, cache *NeoCache, pub *keys.Publ
 	d.DeleteStorageItem(n.ID, makeValidatorKey(pub))
 
 	voterKey := makeVoterKey(pub.Bytes())
-	d.Seek(n.ID, storage.SeekRange{Prefix: voterKey}, func(k, v []byte) bool {
-		d.DeleteStorageItem(n.ID, append(voterKey, k...)) // d.Seek cuts prefix, thus need to append it again.
-		return true
-	})
+	d.DeleteStorageItem(n.ID, voterKey)
 	delete(cache.gasPerVoteCache, string(voterKey))
 
 	return true
@@ -661,7 +640,7 @@ func makeVoterKey(pub []byte, prealloc ...[]byte) []byte {
 	if len(prealloc) != 0 {
 		key = prealloc[0]
 	} else {
-		key = make([]byte, 34, 38)
+		key = make([]byte, 34)
 	}
 	key[0] = prefixVoterRewardPerCommittee
 	copy(key[1:], pub)
@@ -670,29 +649,32 @@ func makeVoterKey(pub []byte, prealloc ...[]byte) []byte {
 
 // 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.Simple, acc util.Uint160, end uint32) (*big.Int, error) {
+func (n *NEO) CalculateBonus(ic *interop.Context, acc util.Uint160, end uint32) (*big.Int, error) {
+	if ic.Block == nil || end != ic.Block.Index {
+		return nil, errors.New("can't calculate bonus of height unequal (BlockHeight + 1)")
+	}
 	key := makeAccountKey(acc)
-	si := d.GetStorageItem(n.ID, key)
+	si := ic.DAO.GetStorageItem(n.ID, key)
 	if si == nil {
 		return nil, storage.ErrKeyNotFound
 	}
 	st, err := state.NEOBalanceFromBytes(si)
 	if err != nil {
 		return nil, err
 	}
-	return n.calculateBonus(d, st.VoteTo, &st.Balance, st.BalanceHeight, end)
+	return n.calculateBonus(ic.DAO, st, end)
 }
 
-func (n *NEO) calculateBonus(d *dao.Simple, 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 {
+func (n *NEO) calculateBonus(d *dao.Simple, acc *state.NEOBalance, end uint32) (*big.Int, error) {
+	r, err := n.CalculateNEOHolderReward(d, &acc.Balance, acc.BalanceHeight, end)
+	if err != nil || acc.VoteTo == nil {
 		return r, err
 	}
 
-	var key = makeVoterKey(vote.Bytes())
-	var reward = n.getGASPerVote(d, key, []uint32{start, end})
-	var tmp = (&reward[1]).Sub(&reward[1], &reward[0])
-	tmp.Mul(tmp, value)
+	var key = makeVoterKey(acc.VoteTo.Bytes())
+	var reward = n.getLatestGASPerVote(d, key)
+	var tmp = big.NewInt(0).Sub(&reward, &acc.LastGasPerVote)
+	tmp.Mul(tmp, &acc.Balance)
 	tmp.Div(tmp, bigVoterRewardFactor)
 	tmp.Add(tmp, r)
 	return tmp, nil
@@ -869,6 +851,9 @@ func (n *NEO) VoteInternal(ic *interop.Context, h util.Uint160, pub *keys.Public
 	if err := n.ModifyAccountVotes(acc, ic.DAO, new(big.Int).Neg(&acc.Balance), false); err != nil {
 		return err
 	}
+	if pub != nil && pub != acc.VoteTo {
+		acc.LastGasPerVote = n.getLatestGASPerVote(ic.DAO, makeVoterKey(pub.Bytes()))
+	}
 	oldVote := acc.VoteTo
 	acc.VoteTo = pub
 	if err := n.ModifyAccountVotes(acc, ic.DAO, &acc.Balance, true); err != nil {

pkg/core/native/native_test/neo_test.go

@@ -3,13 +3,16 @@ package native_test
 import (
 	"bytes"
 	"encoding/json"
+	"fmt"
 	"math"
 	"math/big"
 	"sort"
+	"strings"
 	"testing"
 
 	"github.com/nspcc-dev/neo-go/internal/contracts"
 	"github.com/nspcc-dev/neo-go/internal/random"
+	"github.com/nspcc-dev/neo-go/pkg/compiler"
 	"github.com/nspcc-dev/neo-go/pkg/core/interop/interopnames"
 	"github.com/nspcc-dev/neo-go/pkg/core/native"
 	"github.com/nspcc-dev/neo-go/pkg/core/native/nativenames"
@@ -305,6 +308,15 @@ func TestNEO_GetAccountState(t *testing.T) {
 	neoValidatorInvoker := newNeoValidatorsClient(t)
 	e := neoValidatorInvoker.Executor
 
+	cfg := e.Chain.GetConfig()
+	committeeSize := cfg.GetCommitteeSize(0)
+	validatorSize := cfg.GetNumOfCNs(0)
+	advanceChain := func(t *testing.T) {
+		for i := 0; i < committeeSize; i++ {
+			neoValidatorInvoker.AddNewBlock(t)
+		}
+	}
+
 	t.Run("empty", func(t *testing.T) {
 		neoValidatorInvoker.Invoke(t, stackitem.Null{}, "getAccountState", util.Uint160{})
 	})
@@ -318,8 +330,100 @@ func TestNEO_GetAccountState(t *testing.T) {
 			stackitem.Make(amount),
 			stackitem.Make(lub),
 			stackitem.Null{},
+			stackitem.Make(0),
 		}), "getAccountState", acc.ScriptHash())
 	})
+
+	t.Run("lastGasPerVote", func(t *testing.T) {
+		const (
+			GasPerBlock      = 5
+			VoterRewardRatio = 80
+		)
+		getAccountState := func(t *testing.T, account util.Uint160) *state.NEOBalance {
+			stack, err := neoValidatorInvoker.TestInvoke(t, "getAccountState", account)
+			require.NoError(t, err)
+			as := new(state.NEOBalance)
+			err = as.FromStackItem(stack.Pop().Item())
+			require.NoError(t, err)
+			return as
+		}
+
+		amount := int64(1000)
+		acc := e.NewAccount(t)
+		neoValidatorInvoker.Invoke(t, true, "transfer", e.Validator.ScriptHash(), acc.ScriptHash(), amount, nil)
+		as := getAccountState(t, acc.ScriptHash())
+		require.Equal(t, uint64(amount), as.Balance.Uint64())
+		require.Equal(t, e.Chain.BlockHeight(), as.BalanceHeight)
+		require.Equal(t, uint64(0), as.LastGasPerVote.Uint64())
+		committee, _ := e.Chain.GetCommittee()
+		neoValidatorInvoker.WithSigners(e.Validator, e.Validator.(neotest.MultiSigner).Single(0)).Invoke(t, true, "registerCandidate", committee[0].Bytes())
+		neoValidatorInvoker.WithSigners(acc).Invoke(t, true, "vote", acc.ScriptHash(), committee[0].Bytes())
+		as = getAccountState(t, acc.ScriptHash())
+		require.Equal(t, uint64(0), as.LastGasPerVote.Uint64())
+		advanceChain(t)
+		neoValidatorInvoker.WithSigners(acc).Invoke(t, true, "transfer", acc.ScriptHash(), acc.ScriptHash(), amount, nil)
+		as = getAccountState(t, acc.ScriptHash())
+		expect := GasPerBlock * native.GASFactor * VoterRewardRatio / 100 * (uint64(e.Chain.BlockHeight()) / uint64(committeeSize))
+		expect = expect * uint64(committeeSize) / uint64(validatorSize+committeeSize) * native.NEOTotalSupply / as.Balance.Uint64()
+		require.Equal(t, e.Chain.BlockHeight(), as.BalanceHeight)
+		require.Equal(t, expect, as.LastGasPerVote.Uint64())
+	})
+}
+
+func TestNEO_GetAccountStateInteropAPI(t *testing.T) {
+	neoValidatorInvoker := newNeoValidatorsClient(t)
+	e := neoValidatorInvoker.Executor
+
+	cfg := e.Chain.GetConfig()
+	committeeSize := cfg.GetCommitteeSize(0)
+	validatorSize := cfg.GetNumOfCNs(0)
+	advanceChain := func(t *testing.T) {
+		for i := 0; i < committeeSize; i++ {
+			neoValidatorInvoker.AddNewBlock(t)
+		}
+	}
+
+	amount := int64(1000)
+	acc := e.NewAccount(t)
+	neoValidatorInvoker.Invoke(t, true, "transfer", e.Validator.ScriptHash(), acc.ScriptHash(), amount, nil)
+	committee, _ := e.Chain.GetCommittee()
+	neoValidatorInvoker.WithSigners(e.Validator, e.Validator.(neotest.MultiSigner).Single(0)).Invoke(t, true, "registerCandidate", committee[0].Bytes())
+	neoValidatorInvoker.WithSigners(acc).Invoke(t, true, "vote", acc.ScriptHash(), committee[0].Bytes())
+	advanceChain(t)
+	neoValidatorInvoker.WithSigners(acc).Invoke(t, true, "transfer", acc.ScriptHash(), acc.ScriptHash(), amount, nil)
+
+	var hashAStr string
+	for i := 0; i < util.Uint160Size; i++ {
+		hashAStr += fmt.Sprintf("%#x", acc.ScriptHash()[i])
+		if i != util.Uint160Size-1 {
+			hashAStr += ", "
+		}
+	}
+	src := `package testaccountstate
+	  import (
+		  "github.com/nspcc-dev/neo-go/pkg/interop/native/neo"
+		  "github.com/nspcc-dev/neo-go/pkg/interop"
+	  )
+	  func GetLastGasPerVote() int {
+		  accState := neo.GetAccountState(interop.Hash160{` + hashAStr + `})
+		  if accState == nil {
+			  panic("nil state")
+		  }
+		  return accState.LastGasPerVote
+	  }`
+	ctr := neotest.CompileSource(t, e.Validator.ScriptHash(), strings.NewReader(src), &compiler.Options{
+		Name: "testaccountstate_contract",
+	})
+	e.DeployContract(t, ctr, nil)
+
+	const (
+		GasPerBlock      = 5
+		VoterRewardRatio = 80
+	)
+	expect := GasPerBlock * native.GASFactor * VoterRewardRatio / 100 * (uint64(e.Chain.BlockHeight()) / uint64(committeeSize))
+	expect = expect * uint64(committeeSize) / uint64(validatorSize+committeeSize) * native.NEOTotalSupply / uint64(amount)
+	ctrInvoker := e.NewInvoker(ctr.Hash, e.Committee)
+	ctrInvoker.Invoke(t, stackitem.Make(expect), "getLastGasPerVote")
 }
 
 func TestNEO_CommitteeBountyOnPersist(t *testing.T) {

pkg/core/state/native_state.go

@@ -19,8 +19,9 @@ type NEP17Balance struct {
 // NEOBalance represents the balance state of a NEO-token.
 type NEOBalance struct {
 	NEP17Balance
-	BalanceHeight uint32
-	VoteTo        *keys.PublicKey
+	BalanceHeight  uint32
+	VoteTo         *keys.PublicKey
+	LastGasPerVote big.Int
 }
 
 // NEP17BalanceFromBytes converts the serialized NEP17Balance to a structure.
@@ -125,6 +126,7 @@ func (s *NEOBalance) ToStackItem() (stackitem.Item, error) {
 		stackitem.NewBigInteger(&s.Balance),
 		stackitem.NewBigInteger(big.NewInt(int64(s.BalanceHeight))),
 		voteItem,
+		stackitem.NewBigInteger(&s.LastGasPerVote),
 	}), nil
 }
 
@@ -157,5 +159,12 @@ func (s *NEOBalance) FromStackItem(item stackitem.Item) error {
 		return fmt.Errorf("invalid public key bytes: %w", err)
 	}
 	s.VoteTo = pub
+	if len(structItem) >= 4 {
+		lastGasPerVote, err := structItem[3].TryInteger()
+		if err != nil {
+			return fmt.Errorf("invalid last vote reward per neo stackitem: %w", err)
+		}
+		s.LastGasPerVote = *lastGasPerVote
+	}
 	return nil
 }

pkg/interop/native/neo/neo.go

@@ -15,9 +15,10 @@ import (
 
 // AccountState contains info about a NEO holder.
 type AccountState struct {
-	Balance int
-	Height  int
-	VoteTo  interop.PublicKey
+	Balance        int
+	Height         int
+	VoteTo         interop.PublicKey
+	LastGasPerVote int
 }
 
 // Hash represents NEO contract hash.