core: drop GetStandBy* methods

They're misleading now that we have variable number of committee
members/validators. The standby list can be seen in the configuration and the
appropriate numbers can be received from it also.

internal/fakechain/fakechain.go

@@ -300,16 +300,6 @@ func (chain *FakeChain) GetValidators() ([]*keys.PublicKey, error) {
 	panic("TODO")
 }
 
-// GetStandByCommittee implements Blockchainer interface.
-func (chain *FakeChain) GetStandByCommittee() keys.PublicKeys {
-	panic("TODO")
-}
-
-// GetStandByValidators implements Blockchainer interface.
-func (chain *FakeChain) GetStandByValidators() keys.PublicKeys {
-	panic("TODO")
-}
-
 // GetEnrollments implements Blockchainer interface.
 func (chain *FakeChain) GetEnrollments() ([]state.Validator, error) {
 	panic("TODO")

pkg/core/blockchain.go

@@ -152,8 +152,6 @@ type Blockchain struct {
 	// Block's transactions are passed via mempool.
 	postBlock []func(func(*transaction.Transaction, *mempool.Pool, bool) bool, *mempool.Pool, *block.Block)
 
-	sbCommittee keys.PublicKeys
-
 	log *zap.Logger
 
 	lastBatch *storage.MemBatch
@@ -247,10 +245,6 @@ func NewBlockchain(s storage.Store, cfg config.ProtocolConfiguration, log *zap.L
 				zap.Int("StateSyncInterval", cfg.StateSyncInterval))
 		}
 	}
-	committee, err := committeeFromConfig(cfg)
-	if err != nil {
-		return nil, err
-	}
 	if len(cfg.NativeUpdateHistories) == 0 {
 		cfg.NativeUpdateHistories = map[string][]uint32{}
 		log.Info("NativeActivations are not set, using default values")
@@ -262,7 +256,6 @@ func NewBlockchain(s storage.Store, cfg config.ProtocolConfiguration, log *zap.L
 		stopCh:      make(chan struct{}),
 		runToExitCh: make(chan struct{}),
 		memPool:     mempool.New(cfg.MemPoolSize, 0, false),
-		sbCommittee: committee,
 		log:         log,
 		events:      make(chan bcEvent),
 		subCh:       make(chan interface{}),
@@ -2089,16 +2082,6 @@ func (bc *Blockchain) PoolTxWithData(t *transaction.Transaction, data interface{
 	return bc.verifyAndPoolTx(t, mp, feer, data)
 }
 
-// GetStandByValidators returns validators from the configuration.
-func (bc *Blockchain) GetStandByValidators() keys.PublicKeys {
-	return bc.sbCommittee[:bc.config.GetNumOfCNs(bc.BlockHeight())].Copy()
-}
-
-// GetStandByCommittee returns standby committee from the configuration.
-func (bc *Blockchain) GetStandByCommittee() keys.PublicKeys {
-	return bc.sbCommittee.Copy()
-}
-
 // GetCommittee returns the sorted list of public keys of nodes in committee.
 func (bc *Blockchain) GetCommittee() (keys.PublicKeys, error) {
 	pubs := bc.contracts.NEO.GetCommitteeMembers()

pkg/core/blockchainer/blockchainer.go

@@ -56,8 +56,6 @@ type Blockchainer interface {
 	GetNotaryContractScriptHash() util.Uint160
 	GetNotaryBalance(acc util.Uint160) *big.Int
 	GetValidators() ([]*keys.PublicKey, error)
-	GetStandByCommittee() keys.PublicKeys
-	GetStandByValidators() keys.PublicKeys
 	GetStateModule() StateRoot
 	GetStorageItem(id int32, key []byte) state.StorageItem
 	GetStorageItems(id int32) ([]state.StorageItemWithKey, error)

pkg/core/interop/context.go

@@ -15,7 +15,6 @@ import (
 	"github.com/nspcc-dev/neo-go/pkg/core/state"
 	"github.com/nspcc-dev/neo-go/pkg/core/transaction"
 	"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/io"
 	"github.com/nspcc-dev/neo-go/pkg/smartcontract/callflag"
 	"github.com/nspcc-dev/neo-go/pkg/smartcontract/manifest"
@@ -42,8 +41,6 @@ type Ledger interface {
 	GetBlock(hash util.Uint256) (*block.Block, error)
 	GetConfig() config.ProtocolConfiguration
 	GetHeaderHash(int) util.Uint256
-	GetStandByCommittee() keys.PublicKeys
-	GetStandByValidators() keys.PublicKeys
 	GetStoragePrice() int64
 }
 

pkg/core/native/native_gas.go

@@ -10,6 +10,7 @@ import (
 	"github.com/nspcc-dev/neo-go/pkg/core/state"
 	"github.com/nspcc-dev/neo-go/pkg/core/transaction"
 	"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/smartcontract"
 	"github.com/nspcc-dev/neo-go/pkg/util"
 )
@@ -135,7 +136,12 @@ func (g *GAS) BalanceOf(d dao.DAO, acc util.Uint160) *big.Int {
 }
 
 func getStandbyValidatorsHash(ic *interop.Context) (util.Uint160, error) {
-	s, err := smartcontract.CreateDefaultMultiSigRedeemScript(ic.Chain.GetStandByValidators())
+	cfg := ic.Chain.GetConfig()
+	committee, err := keys.NewPublicKeysFromStrings(cfg.StandbyCommittee)
+	if err != nil {
+		return util.Uint160{}, err
+	}
+	s, err := smartcontract.CreateDefaultMultiSigRedeemScript(committee[:cfg.GetNumOfCNs(0)])
 	if err != nil {
 		return util.Uint160{}, err
 	}

pkg/core/native/native_neo.go

@@ -10,6 +10,7 @@ import (
 	"strings"
 	"sync/atomic"
 
+	"github.com/nspcc-dev/neo-go/pkg/config"
 	"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"
@@ -54,6 +55,10 @@ type NEO struct {
 	// It is set in state-modifying methods only and read in `PostPersist` thus is not protected
 	// by any mutex.
 	gasPerVoteCache map[string]big.Int
+	// Configuration and standby keys are set during initialization and then
+	// only read from.
+	cfg         config.ProtocolConfiguration
+	standbyKeys keys.PublicKeys
 }
 
 const (
@@ -190,6 +195,10 @@ func newNEO() *NEO {
 
 // Initialize initializes NEO contract.
 func (n *NEO) Initialize(ic *interop.Context) error {
+	err := n.initConfigCache(ic.Chain)
+	if err != nil {
+		return nil
+	}
 	if err := n.nep17TokenNative.Initialize(ic); err != nil {
 		return err
 	}
@@ -199,9 +208,9 @@ func (n *NEO) Initialize(ic *interop.Context) error {
 		return errors.New("already initialized")
 	}
 
-	committee := ic.Chain.GetStandByCommittee()
-	cvs := toKeysWithVotes(committee)
-	err := n.updateCache(cvs, ic.Chain)
+	committee0 := n.standbyKeys[:n.cfg.GetCommitteeSize(ic.Block.Index)]
+	cvs := toKeysWithVotes(committee0)
+	err = n.updateCache(cvs, ic.Chain)
 	if err != nil {
 		return err
 	}
@@ -244,6 +253,10 @@ 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 interop.Ledger, d dao.DAO) error {
+	err := n.initConfigCache(bc)
+	if err != nil {
+		return nil
+	}
 	var committee = keysWithVotes{}
 	si := d.GetStorageItem(n.ID, prefixCommittee)
 	if err := committee.DecodeBytes(si); err != nil {
@@ -263,6 +276,14 @@ func (n *NEO) InitializeCache(bc interop.Ledger, d dao.DAO) error {
 	return nil
 }
 
+func (n *NEO) initConfigCache(bc interop.Ledger) error {
+	var err error
+
+	n.cfg = bc.GetConfig()
+	n.standbyKeys, err = keys.NewPublicKeysFromStrings(n.cfg.StandbyCommittee)
+	return err
+}
+
 func (n *NEO) updateCache(cvs keysWithVotes, bc interop.Ledger) error {
 	n.committee.Store(cvs)
 
@@ -273,8 +294,7 @@ func (n *NEO) updateCache(cvs keysWithVotes, bc interop.Ledger) error {
 	}
 	n.committeeHash.Store(hash.Hash160(script))
 
-	cfg := bc.GetConfig()
-	nextVals := committee[:cfg.GetNumOfCNs(bc.BlockHeight()+1)].Copy()
+	nextVals := committee[:n.cfg.GetNumOfCNs(bc.BlockHeight()+1)].Copy()
 	sort.Sort(nextVals)
 	n.nextValidators.Store(nextVals)
 	return nil
@@ -301,12 +321,11 @@ func (n *NEO) updateCommittee(ic *interop.Context) error {
 
 // OnPersist implements Contract interface.
 func (n *NEO) OnPersist(ic *interop.Context) error {
-	cfg := ic.Chain.GetConfig()
-	if cfg.ShouldUpdateCommitteeAt(ic.Block.Index) {
+	if n.cfg.ShouldUpdateCommitteeAt(ic.Block.Index) {
 		oldKeys := n.nextValidators.Load().(keys.PublicKeys)
 		oldCom := n.committee.Load().(keysWithVotes)
-		if cfg.GetNumOfCNs(ic.Block.Index) != len(oldKeys) ||
-			cfg.GetCommitteeSize(ic.Block.Index) != len(oldCom) {
+		if n.cfg.GetNumOfCNs(ic.Block.Index) != len(oldKeys) ||
+			n.cfg.GetCommitteeSize(ic.Block.Index) != len(oldCom) {
 			n.votesChanged.Store(true)
 		}
 		if err := n.updateCommittee(ic); err != nil {
@@ -320,17 +339,16 @@ 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()
-	cfg := ic.Chain.GetConfig()
-	committeeSize := cfg.GetCommitteeSize(ic.Block.Index)
+	committeeSize := n.cfg.GetCommitteeSize(ic.Block.Index)
 	index := int(ic.Block.Index) % committeeSize
 	committeeReward := new(big.Int).Mul(gas, bigCommitteeRewardRatio)
 	n.GAS.mint(ic, pubs[index].GetScriptHash(), committeeReward.Div(committeeReward, big100), false)
 
-	if cfg.ShouldUpdateCommitteeAt(ic.Block.Index) {
+	if n.cfg.ShouldUpdateCommitteeAt(ic.Block.Index) {
 		var voterReward = new(big.Int).Set(bigVoterRewardRatio)
 		voterReward.Mul(voterReward, gas)
 		voterReward.Mul(voterReward, big.NewInt(voterRewardFactor*int64(committeeSize)))
-		var validatorsCount = cfg.GetNumOfCNs(ic.Block.Index)
+		var validatorsCount = n.cfg.GetNumOfCNs(ic.Block.Index)
 		voterReward.Div(voterReward, big.NewInt(int64(committeeSize+validatorsCount)))
 		voterReward.Div(voterReward, big100)
 
@@ -940,8 +958,7 @@ func (n *NEO) getAccountState(ic *interop.Context, args []stackitem.Item) stacki
 
 // ComputeNextBlockValidators returns an actual list of current validators.
 func (n *NEO) ComputeNextBlockValidators(bc interop.Ledger, d dao.DAO) (keys.PublicKeys, error) {
-	cfg := bc.GetConfig()
-	numOfCNs := cfg.GetNumOfCNs(bc.BlockHeight() + 1)
+	numOfCNs := n.cfg.GetNumOfCNs(bc.BlockHeight() + 1)
 	if vals := n.validators.Load().(keys.PublicKeys); vals != nil && numOfCNs == len(vals) {
 		return vals.Copy(), nil
 	}
@@ -1010,10 +1027,9 @@ func (n *NEO) computeCommitteeMembers(bc interop.Ledger, d dao.DAO) (keys.Public
 	_, totalSupply := n.getTotalSupply(d)
 	voterTurnout := votersCount.Div(votersCount, totalSupply)
 
-	sbVals := bc.GetStandByCommittee()
-	cfg := bc.GetConfig()
-	count := cfg.GetCommitteeSize(bc.BlockHeight() + 1)
-	sbVals = sbVals[:count]
+	count := n.cfg.GetCommitteeSize(bc.BlockHeight() + 1)
+	// Can be sorted and/or returned to outside users, thus needs to be copied.
+	sbVals := keys.PublicKeys(n.standbyKeys[:count]).Copy()
 	cs, err := n.getCandidates(d, false)
 	if err != nil {
 		return nil, nil, err

pkg/core/native/native_test/neo_test.go

@@ -50,8 +50,9 @@ func TestNEO_Vote(t *testing.T) {
 	neoValidatorsInvoker := neoCommitteeInvoker.WithSigners(neoCommitteeInvoker.Validator)
 	e := neoCommitteeInvoker.Executor
 
-	committeeSize := len(neoValidatorsInvoker.Chain.GetConfig().StandbyCommittee)
-	validatorsCount := neoCommitteeInvoker.Chain.GetConfig().ValidatorsCount
+	cfg := e.Chain.GetConfig()
+	committeeSize := cfg.GetCommitteeSize(0)
+	validatorsCount := cfg.GetNumOfCNs(0)
 	freq := validatorsCount + committeeSize
 	advanceChain := func(t *testing.T) {
 		for i := 0; i < freq; i++ {
@@ -59,7 +60,9 @@ func TestNEO_Vote(t *testing.T) {
 		}
 	}
 
-	standBySorted := e.Chain.GetStandByValidators()
+	standBySorted, err := keys.NewPublicKeysFromStrings(e.Chain.GetConfig().StandbyCommittee)
+	require.NoError(t, err)
+	standBySorted = standBySorted[:validatorsCount]
 	sort.Sort(standBySorted)
 	pubs, err := e.Chain.GetValidators()
 	require.NoError(t, err)
@@ -250,7 +253,8 @@ func TestNEO_CommitteeBountyOnPersist(t *testing.T) {
 	neoCommitteeInvoker := newNeoCommitteeClient(t, 0)
 	e := neoCommitteeInvoker.Executor
 
-	hs := e.Chain.GetStandByCommittee()
+	hs, err := keys.NewPublicKeysFromStrings(e.Chain.GetConfig().StandbyCommittee)
+	require.NoError(t, err)
 	committeeSize := len(hs)
 
 	const singleBounty = 50000000

pkg/core/util.go

@@ -49,25 +49,13 @@ func createGenesisBlock(cfg config.ProtocolConfiguration) (*block.Block, error)
 }
 
 func validatorsFromConfig(cfg config.ProtocolConfiguration) ([]*keys.PublicKey, error) {
-	vs, err := committeeFromConfig(cfg)
+	vs, err := keys.NewPublicKeysFromStrings(cfg.StandbyCommittee)
 	if err != nil {
 		return nil, err
 	}
 	return vs[:cfg.GetNumOfCNs(0)], nil
 }
 
-func committeeFromConfig(cfg config.ProtocolConfiguration) ([]*keys.PublicKey, error) {
-	validators := make([]*keys.PublicKey, len(cfg.StandbyCommittee))
-	for i := range validators {
-		pubKey, err := keys.NewPublicKeyFromString(cfg.StandbyCommittee[i])
-		if err != nil {
-			return nil, err
-		}
-		validators[i] = pubKey
-	}
-	return validators, nil
-}
-
 func getNextConsensusAddress(validators []*keys.PublicKey) (val util.Uint160, err error) {
 	raw, err := smartcontract.CreateDefaultMultiSigRedeemScript(validators)
 	if err != nil {

pkg/crypto/keys/publickey.go

@@ -32,6 +32,20 @@ type PublicKeys []*PublicKey
 var big0 = big.NewInt(0)
 var big3 = big.NewInt(3)
 
+// NewPublicKeysFromStrings converts an array of string-encoded P256 public keys
+// into an array of PublicKeys.
+func NewPublicKeysFromStrings(ss []string) (PublicKeys, error) {
+	arr := make([]*PublicKey, len(ss))
+	for i := range ss {
+		pubKey, err := NewPublicKeyFromString(ss[i])
+		if err != nil {
+			return nil, err
+		}
+		arr[i] = pubKey
+	}
+	return PublicKeys(arr), nil
+}
+
 func (keys PublicKeys) Len() int      { return len(keys) }
 func (keys PublicKeys) Swap(i, j int) { keys[i], keys[j] = keys[j], keys[i] }
 func (keys PublicKeys) Less(i, j int) bool {

pkg/rpc/server/server_test.go

@@ -699,8 +699,7 @@ var rpcTestCases = map[string][]rpcTestCase{
 		{
 			params: "[]",
 			result: func(e *executor) interface{} {
-				// it's a test chain, so committee is a sorted standby committee
-				expected := e.chain.GetStandByCommittee()
+				expected, _ := e.chain.GetCommittee()
 				sort.Sort(expected)
 				return &expected
 			},

scripts/gendump/main.go

@@ -64,7 +64,9 @@ func main() {
 	bc, err := newChain()
 	handleError("can't initialize blockchain", err)
 
-	valScript, err := smartcontract.CreateDefaultMultiSigRedeemScript(bc.GetStandByValidators())
+	nbVals, err := bc.GetNextBlockValidators()
+	handleError("can't get next block validators", err)
+	valScript, err := smartcontract.CreateDefaultMultiSigRedeemScript(nbVals)
 	handleError("can't create verification script", err)
 	lastBlock, err := bc.GetBlock(bc.GetHeaderHash(int(bc.BlockHeight())))
 	handleError("can't fetch last block", err)