Removed outdated flag, additional checks and simplified logic. (#4621)

* Removed outdated flag and simplified logic.

* Removed outdated flag and simplified logic.

* Added additional logs.

consensus/consensus_v2.go

@@ -679,7 +679,7 @@ func (consensus *Consensus) commitBlock(blk *types.Block, committedMsg *FBFTMess
 
 // rotateLeader rotates the leader to the next leader in the committee.
 // This function must be called with enabled leader rotation.
-func (consensus *Consensus) rotateLeader(epoch *big.Int) *bls.PublicKeyWrapper {
+func (consensus *Consensus) rotateLeader(epoch *big.Int, defaultKey *bls.PublicKeyWrapper) *bls.PublicKeyWrapper {
 	var (
 		bc        = consensus.Blockchain()
 		leader    = consensus.getLeaderPubKey()
@@ -687,31 +687,32 @@ func (consensus *Consensus) rotateLeader(epoch *big.Int) *bls.PublicKeyWrapper {
 		curNumber = curBlock.NumberU64()
 		curEpoch  = curBlock.Epoch().Uint64()
 	)
+	if epoch.Uint64() != curEpoch {
+		return defaultKey
+	}
 	const blocksCountAliveness = 4
-
 	utils.Logger().Info().Msgf("[Rotating leader] epoch: %v rotation:%v external rotation %v", epoch.Uint64(), bc.Config().IsLeaderRotationInternalValidators(epoch), bc.Config().IsLeaderRotationExternalValidatorsAllowed(epoch))
 	ss, err := bc.ReadShardState(epoch)
 	if err != nil {
 		utils.Logger().Error().Err(err).Msg("Failed to read shard state")
-		return nil
+		return defaultKey
 	}
 	committee, err := ss.FindCommitteeByID(consensus.ShardID)
 	if err != nil {
 		utils.Logger().Error().Err(err).Msg("Failed to find committee")
-		return nil
+		return defaultKey
 	}
 	slotsCount := len(committee.Slots)
 	blocksPerEpoch := shard.Schedule.InstanceForEpoch(epoch).BlocksPerEpoch()
 	if blocksPerEpoch == 0 {
 		utils.Logger().Error().Msg("[Rotating leader] blocks per epoch is 0")
-		return nil
+		return defaultKey
 	}
 	if slotsCount == 0 {
 		utils.Logger().Error().Msg("[Rotating leader] slots count is 0")
-		return nil
+		return defaultKey
 	}
 	numBlocksProducedByLeader := blocksPerEpoch / uint64(slotsCount)
-	rest := blocksPerEpoch % uint64(slotsCount)
 	const minimumBlocksForLeaderInRow = blocksCountAliveness
 	if numBlocksProducedByLeader < minimumBlocksForLeaderInRow {
 		// mine no less than 3 blocks in a row
@@ -720,15 +721,11 @@ func (consensus *Consensus) rotateLeader(epoch *big.Int) *bls.PublicKeyWrapper {
 	s := bc.LeaderRotationMeta()
 	if !bytes.Equal(leader.Bytes[:], s.Pub) {
 		// Another leader.
-		return nil
+		return defaultKey
-	}
-	// If it is the first validator producing blocks, it should also produce the remaining 'rest' of the blocks.
-	if s.Shifts == 0 {
-		numBlocksProducedByLeader += rest
 	}
 	if s.Count < numBlocksProducedByLeader {
 		// Not enough blocks produced by the leader, continue producing by the same leader.
-		return nil
+		return defaultKey
 	}
 	// Passed all checks, we can change leader.
 	// NthNext will move the leader to the next leader in the committee.
@@ -748,7 +745,7 @@ func (consensus *Consensus) rotateLeader(epoch *big.Int) *bls.PublicKeyWrapper {
 		if !wasFound {
 			utils.Logger().Error().Msg("Failed to get next leader")
 			// Seems like nothing we can do here.
-			return nil
+			return defaultKey
 		}
 		members := consensus.decider.Participants()
 		mask := bls.NewMask(members)
@@ -757,7 +754,7 @@ func (consensus *Consensus) rotateLeader(epoch *big.Int) *bls.PublicKeyWrapper {
 			header := bc.GetHeaderByNumber(curNumber - uint64(i))
 			if header == nil {
 				utils.Logger().Error().Msgf("Failed to get header by number %d", curNumber-uint64(i))
-				return nil
+				return defaultKey
 			}
 			// if epoch is different, we should not check this block.
 			if header.Epoch().Uint64() != curEpoch {
@@ -767,12 +764,12 @@ func (consensus *Consensus) rotateLeader(epoch *big.Int) *bls.PublicKeyWrapper {
 			err = mask.SetMask(header.LastCommitBitmap())
 			if err != nil {
 				utils.Logger().Err(err).Msg("Failed to set mask")
-				return nil
+				return defaultKey
 			}
 			ok, err := mask.KeyEnabled(next.Bytes)
 			if err != nil {
 				utils.Logger().Err(err).Msg("Failed to get key enabled")
-				return nil
+				return defaultKey
 			}
 			if !ok {
 				skipped++
@@ -787,14 +784,13 @@ func (consensus *Consensus) rotateLeader(epoch *big.Int) *bls.PublicKeyWrapper {
 		}
 		return next
 	}
-	return nil
+	return defaultKey
 }
 
 // SetupForNewConsensus sets the state for new consensus
 func (consensus *Consensus) setupForNewConsensus(blk *types.Block, committedMsg *FBFTMessage) {
 	atomic.StoreUint64(&consensus.blockNum, blk.NumberU64()+1)
 	consensus.setCurBlockViewID(committedMsg.ViewID + 1)
-	consensus.LeaderPubKey = committedMsg.SenderPubkeys[0]
 	var epoch *big.Int
 	if blk.IsLastBlockInEpoch() {
 		epoch = new(big.Int).Add(blk.Epoch(), common.Big1)
@@ -802,9 +798,14 @@ func (consensus *Consensus) setupForNewConsensus(blk *types.Block, committedMsg
 		epoch = blk.Epoch()
 	}
 	if consensus.Blockchain().Config().IsLeaderRotationInternalValidators(epoch) {
-		if next := consensus.rotateLeader(epoch); next != nil {
+		if next := consensus.rotateLeader(epoch, committedMsg.SenderPubkeys[0]); next != nil {
 			prev := consensus.getLeaderPubKey()
 			consensus.setLeaderPubKey(next)
+			if consensus.isLeader() {
+				utils.Logger().Info().Msgf("We are block %d, I am the new leader %s", blk.NumberU64(), next.Bytes.Hex())
+			} else {
+				utils.Logger().Info().Msgf("We are block %d, the leader is %s", blk.NumberU64(), next.Bytes.Hex())
+			}
 			if consensus.isLeader() && !consensus.getLeaderPubKey().Object.IsEqual(prev.Object) {
 				// leader changed
 				blockPeriod := consensus.BlockPeriod

core/blockchain_leader_rotation.go

@@ -14,10 +14,9 @@ import (
 
 // LeaderRotationMeta contains information about leader rotation
 type LeaderRotationMeta struct {
-	Pub    []byte // bls public key of previous block miner
+	Pub   []byte // bls public key of previous block miner
-	Epoch  uint64 // epoch number of previously inserted block
+	Epoch uint64 // epoch number of previously inserted block
-	Count  uint64 // quantity of continuous blocks inserted by the same leader
+	Count uint64 // quantity of continuous blocks inserted by the same leader
-	Shifts uint64 // number of leader shifts, shift happens when leader changes
 }
 
 // ShortString returns string representation of the struct
@@ -28,8 +27,6 @@ func (a LeaderRotationMeta) ShortString() string {
 	s.WriteString(strconv.FormatUint(a.Epoch, 10))
 	s.WriteString(" ")
 	s.WriteString(strconv.FormatUint(a.Count, 10))
-	s.WriteString(" ")
-	s.WriteString(strconv.FormatUint(a.Shifts, 10))
 	return s.String()
 }
 
@@ -39,17 +36,15 @@ func (a LeaderRotationMeta) Hash() []byte {
 	c.Write(a.Pub)
 	c.Write([]byte(strconv.FormatUint(a.Epoch, 10)))
 	c.Write([]byte(strconv.FormatUint(a.Count, 10)))
-	c.Write([]byte(strconv.FormatUint(a.Shifts, 10)))
 	return c.Sum(nil)
 }
 
 // Clone returns a copy of the struct
 func (a LeaderRotationMeta) Clone() LeaderRotationMeta {
 	return LeaderRotationMeta{
-		Pub:    append([]byte{}, a.Pub...),
+		Pub:   append([]byte{}, a.Pub...),
-		Epoch:  a.Epoch,
+		Epoch: a.Epoch,
-		Count:  a.Count,
+		Count: a.Count,
-		Shifts: a.Shifts,
 	}
 }
 
@@ -109,19 +104,10 @@ func processRotationMeta(epoch uint64, blockPubKey bls.SerializedPublicKey, s Le
 	} else {
 		s.Count = 1
 	}
-	// we should increase shifts if the leader has changed.
-	if !bytes.Equal(s.Pub, blockPubKey[:]) {
-		s.Shifts++
-	}
-	// but set to zero if new
-	if s.Epoch != epoch {
-		s.Shifts = 0
-	}
 	s.Epoch = epoch
 	return LeaderRotationMeta{
-		Pub:    blockPubKey[:],
+		Pub:   blockPubKey[:],
-		Epoch:  s.Epoch,
+		Epoch: s.Epoch,
-		Count:  s.Count,
+		Count: s.Count,
-		Shifts: s.Shifts,
 	}
 }

core/blockchain_leader_rotation_test.go

@@ -12,46 +12,27 @@ var k1 = bls.SerializedPublicKey{1, 2, 3}
 func TestRotationMetaProcess(t *testing.T) {
 	t.Run("same_leader_increase_count", func(t *testing.T) {
 		rs := processRotationMeta(1, bls.SerializedPublicKey{}, LeaderRotationMeta{
-			Pub:    bls.SerializedPublicKey{}.Bytes(),
+			Pub:   bls.SerializedPublicKey{}.Bytes(),
-			Epoch:  1,
+			Epoch: 1,
-			Count:  1,
+			Count: 1,
-			Shifts: 1,
 		})
 		require.Equal(t, LeaderRotationMeta{
-			Pub:    bls.SerializedPublicKey{}.Bytes(),
+			Pub:   bls.SerializedPublicKey{}.Bytes(),
-			Epoch:  1,
+			Epoch: 1,
-			Count:  2,
+			Count: 2,
-			Shifts: 1,
-		}, rs)
-	})
-
-	t.Run("new_leader_increase_shifts", func(t *testing.T) {
-		rs := processRotationMeta(1, k1, LeaderRotationMeta{
-			Pub:    bls.SerializedPublicKey{}.Bytes(),
-			Epoch:  1,
-			Count:  1,
-			Shifts: 1,
-		})
-		require.Equal(t, LeaderRotationMeta{
-			Pub:    k1.Bytes(),
-			Epoch:  1,
-			Count:  1,
-			Shifts: 2,
 		}, rs)
 	})
 
 	t.Run("new_epoch_reset_count", func(t *testing.T) {
 		rs := processRotationMeta(2, k1, LeaderRotationMeta{
-			Pub:    bls.SerializedPublicKey{}.Bytes(),
+			Pub:   bls.SerializedPublicKey{}.Bytes(),
-			Epoch:  1,
+			Epoch: 1,
-			Count:  1,
+			Count: 1,
-			Shifts: 1,
 		})
 		require.Equal(t, LeaderRotationMeta{
-			Pub:    k1.Bytes(),
+			Pub:   k1.Bytes(),
-			Epoch:  2,
+			Epoch: 2,
-			Count:  1,
+			Count: 1,
-			Shifts: 0,
 		}, rs)
 	})
 }