HIP-30: Emission split

core/staking_verifier.go

@@ -171,11 +171,20 @@ func VerifyAndEditValidatorFromMsg(
 		return nil, errCommissionRateChangeTooHigh
 	}
 
-	if chainContext.Config().IsMinCommissionRate(epoch) && newRate.LT(availability.MinCommissionRate) {
+	minRate := availability.MinCommissionRate(
+		chainContext.Config().IsMinCommissionRate(epoch),
+		chainContext.Config().IsHIP30(epoch),
+	)
+	if newRate.LT(minRate) {
 		firstEpoch := stateDB.GetValidatorFirstElectionEpoch(msg.ValidatorAddress)
 		promoPeriod := chainContext.Config().MinCommissionPromoPeriod.Int64()
 		if firstEpoch.Uint64() != 0 && big.NewInt(0).Sub(epoch, firstEpoch).Int64() >= promoPeriod {
-			return nil, errCommissionRateChangeTooLow
+			return nil,
+				errors.Errorf(
+					"%s %d%%",
+					errCommissionRateChangeTooLowT,
+					minRate.MulInt64(100).Int64(),
+				)
 		}
 	}
 

core/staking_verifier_test.go

@@ -676,7 +676,7 @@ func TestVerifyAndEditValidatorFromMsg(t *testing.T) {
 				return msg
 			}(),
 
-			expErr: errCommissionRateChangeTooLow,
+			expErr: errCommissionRateChangeTooLowT,
 		},
 		{
 			// 15: Rate is ok within the promo period

core/state_transition.go

@@ -40,7 +40,7 @@ var (
 	errNoDelegationToUndelegate    = errors.New("no delegation to undelegate")
 	errCommissionRateChangeTooFast = errors.New("change on commission rate can not be more than max change rate within the same epoch")
 	errCommissionRateChangeTooHigh = errors.New("commission rate can not be higher than maximum commission rate")
-	errCommissionRateChangeTooLow  = errors.New("commission rate can not be lower than min rate of 5%")
+	errCommissionRateChangeTooLowT = errors.New("commission rate can not be lower than min rate of ")
 	errNoRewardsToCollect          = errors.New("no rewards to collect")
 	errNegativeAmount              = errors.New("amount can not be negative")
 	errDupIdentity                 = errors.New("validator identity exists")

internal/chain/engine.go

@@ -6,7 +6,9 @@ import (
 	"sort"
 	"time"
 
+	"github.com/harmony-one/harmony/common/denominations"
 	"github.com/harmony-one/harmony/internal/params"
+	"github.com/harmony-one/harmony/numeric"
 
 	bls2 "github.com/harmony-one/bls/ffi/go/bls"
 	blsvrf "github.com/harmony-one/harmony/crypto/vrf/bls"
@@ -285,7 +287,7 @@ func (e *engineImpl) Finalize(
 		// depends on the old LastEpochInCommittee
 
 		startTime = time.Now()
-		if err := setElectionEpochAndMinFee(header, state, chain.Config()); err != nil {
+		if err := setElectionEpochAndMinFee(chain, header, state, chain.Config()); err != nil {
 			return nil, nil, err
 		}
 		utils.Logger().Debug().Int64("elapsed time", time.Now().Sub(startTime).Milliseconds()).Msg("SetElectionEpochAndMinFee")
@@ -311,7 +313,7 @@ func (e *engineImpl) Finalize(
 
 	// Accumulate block rewards and commit the final state root
 	// Header seems complete, assemble into a block and return
-	payout, err := AccumulateRewardsAndCountSigs(
+	remainder, payout, err := AccumulateRewardsAndCountSigs(
 		chain, state, header, beacon, sigsReady,
 	)
 	if err != nil {
@@ -331,6 +333,23 @@ func (e *engineImpl) Finalize(
 	// TODO: make the viewID fetch from caller of the block proposal.
 	header.SetViewID(new(big.Int).SetUint64(viewID()))
 
+	// Add the emission recovery split to the balance
+	if chain.Config().IsHIP30(header.Epoch()) {
+		// convert to ONE - note that numeric.Dec
+		// is designed for staking decimals and not
+		// ONE balances so we use big.Int for this math
+		remainderOne := new(big.Int).Div(
+			remainder.Int, big.NewInt(denominations.One),
+		)
+		// this goes directly to the balance (on shard 0, of course)
+		// because the reward mechanism isn't built to handle
+		// rewards not obtained from any delegations
+		state.AddBalance(
+			shard.Schedule.InstanceForEpoch(header.Epoch()).
+				HIP30RecoveryAddress(),
+			remainderOne,
+		)
+	}
 	// Finalize the state root
 	header.SetRoot(state.IntermediateRoot(chain.Config().IsS3(header.Epoch())))
 	return types.NewBlock(header, txs, receipts, outcxs, incxs, stks), payout, nil
@@ -390,12 +409,23 @@ func IsCommitteeSelectionBlock(chain engine.ChainReader, header *block.Header) b
 	return isBeaconChain && header.IsLastBlockInEpoch() && inPreStakingEra
 }
 
-func setElectionEpochAndMinFee(header *block.Header, state *state.DB, config *params.ChainConfig) error {
+func setElectionEpochAndMinFee(chain engine.ChainReader, header *block.Header, state *state.DB, config *params.ChainConfig) error {
 	newShardState, err := header.GetShardState()
 	if err != nil {
 		const msg = "[Finalize] failed to read shard state"
 		return errors.New(msg)
 	}
+	// these 2 should be created outside of loop to optimize
+	minRate := availability.MinCommissionRate(
+		config.IsMinCommissionRate(newShardState.Epoch),
+		config.IsHIP30(newShardState.Epoch),
+	)
+	minRateNotZero := !minRate.Equal(numeric.ZeroDec())
+	// elected validators have their fee updated, if required to do so
+	isElected := make(
+		map[common.Address]struct{},
+		len(newShardState.StakedValidators().Addrs),
+	)
 	for _, addr := range newShardState.StakedValidators().Addrs {
 		wrapper, err := state.ValidatorWrapper(addr, true, false)
 		if err != nil {
@@ -405,14 +435,32 @@ func setElectionEpochAndMinFee(header *block.Header, state *state.DB, config *pa
 		}
 		// Set last epoch in committee
 		wrapper.LastEpochInCommittee = newShardState.Epoch
-
-		if config.IsMinCommissionRate(newShardState.Epoch) {
-			// Set first election epoch
+		if minRateNotZero {
+			// Set first election epoch (applies only if previously unset)
 			state.SetValidatorFirstElectionEpoch(addr, newShardState.Epoch)
-
 			// Update minimum commission fee
-			if err := availability.UpdateMinimumCommissionFee(
-				newShardState.Epoch, state, addr, config.MinCommissionPromoPeriod.Int64(),
+			if _, err := availability.UpdateMinimumCommissionFee(
+				newShardState.Epoch, state, addr, minRate,
+				config.MinCommissionPromoPeriod.Uint64(),
+			); err != nil {
+				return err
+			}
+		}
+		isElected[addr] = struct{}{}
+	}
+	// due to a bug in the old implementation of the minimum fee,
+	// unelected validators did not have their fee updated even
+	// when the protocol required them to do so. here we fix it,
+	// but only after the HIP-30 hard fork is effective.
+	if config.IsHIP30(newShardState.Epoch) {
+		for _, addr := range chain.ValidatorCandidates() {
+			// skip elected validator
+			if _, ok := isElected[addr]; ok {
+				continue
+			}
+			if _, err := availability.UpdateMinimumCommissionFee(
+				newShardState.Epoch, state, addr, minRate,
+				config.MinCommissionPromoPeriod.Uint64(),
 			); err != nil {
 				return err
 			}