A few bug fixes; simulation testing; testcases

cmd/gaia/app/app.go

@@ -154,7 +154,7 @@ func NewGaiaApp(logger log.Logger, db dbm.DB, traceStore io.Writer, loadLatest b
 
 	app.QueryRouter().
 		AddRoute(gov.QuerierRoute, gov.NewQuerier(app.govKeeper)).
-    AddRoute(slashing.QuerierRoute, slashing.NewQuerier(app.slashingKeeper, app.cdc)).
+		AddRoute(slashing.QuerierRoute, slashing.NewQuerier(app.slashingKeeper, app.cdc)).
 		AddRoute(stake.QuerierRoute, stake.NewQuerier(app.stakeKeeper, app.cdc))
 
 	// initialize BaseApp
@@ -370,3 +370,11 @@ func (h StakingHooks) OnDelegationRemoved(ctx sdk.Context, delAddr sdk.AccAddres
 	h.dh.OnDelegationRemoved(ctx, delAddr, valAddr)
 	h.sh.OnDelegationRemoved(ctx, delAddr, valAddr)
 }
+func (h StakingHooks) AfterDelegationModified(ctx sdk.Context, delAddr sdk.AccAddress, valAddr sdk.ValAddress) {
+	h.dh.AfterDelegationModified(ctx, delAddr, valAddr)
+	h.sh.AfterDelegationModified(ctx, delAddr, valAddr)
+}
+func (h StakingHooks) BeforeValidatorSlashed(ctx sdk.Context, valAddr sdk.ValAddress, fraction sdk.Dec) {
+	h.dh.BeforeValidatorSlashed(ctx, valAddr, fraction)
+	h.sh.BeforeValidatorSlashed(ctx, valAddr, fraction)
+}

docs/examples/democoin/mock/validator.go

@@ -69,6 +69,11 @@ func (v Validator) GetMoniker() string {
 	return ""
 }
 
+// Implements sdk.Validator
+func (v Validator) GetDelegatorShareExRate() sdk.Dec {
+	return sdk.ZeroDec()
+}
+
 // Implements sdk.Validator
 type ValidatorSet struct {
 	Validators []Validator

types/stake.go

@@ -45,8 +45,9 @@ type Validator interface {
 	GetPower() Int                // validation power
 	GetTokens() Int               // validation tokens
 	GetCommission() Dec           // validator commission rate
-	GetDelegatorShares() Dec      // Total out standing delegator shares
+	GetDelegatorShares() Dec      // total outstanding delegator shares
 	GetBondHeight() int64         // height in which the validator became active
+	GetDelegatorShareExRate() Dec // tokens per delegator share exchange rate
 }
 
 // validator which fulfills abci validator interface for use in Tendermint
@@ -126,4 +127,6 @@ type StakingHooks interface {
 	OnDelegationCreated(ctx Context, delAddr AccAddress, valAddr ValAddress)        // Must be called when a delegation is created
 	OnDelegationSharesModified(ctx Context, delAddr AccAddress, valAddr ValAddress) // Must be called when a delegation's shares are modified
 	OnDelegationRemoved(ctx Context, delAddr AccAddress, valAddr ValAddress)        // Must be called when a delegation is removed
+	AfterDelegationModified(ctx Context, delAddr AccAddress, valAddr ValAddress)
+	BeforeValidatorSlashed(ctx Context, valAddr ValAddress, fraction Dec)
 }

x/distribution/abci_app.go

@@ -19,7 +19,8 @@ func BeginBlocker(ctx sdk.Context, req abci.RequestBeginBlock, k keeper.Keeper)
 		}
 	}
 
-	// TODO This is Tendermint-dependent. ref https://github.com/cosmos/cosmos-sdk/issues/3095
+	// TODO this is Tendermint-dependent
+	// ref https://github.com/cosmos/cosmos-sdk/issues/3095
 	if ctx.BlockHeight() > 1 {
 		previousProposer := k.GetPreviousProposerConsAddr(ctx)
 		k.AllocateTokens(ctx, sumPrecommitPower, totalPower, previousProposer, req.LastCommitInfo.GetVotes())

x/distribution/keeper/allocation.go

@@ -9,28 +9,23 @@ import (
 // allocate fees handles distribution of the collected fees
 func (k Keeper) AllocateTokens(ctx sdk.Context, sumPrecommitPower int64, totalPower int64, proposer sdk.ConsAddress, votes []abci.VoteInfo) {
 
-	// Fetch collected fees & fee pool
+	// fetch collected fees & fee pool
 	feesCollectedInt := k.feeCollectionKeeper.GetCollectedFees(ctx)
 	feesCollected := sdk.NewDecCoins(feesCollectedInt)
 	feePool := k.GetFeePool(ctx)
 
-	// Clear collected fees, which will now be distributed
+	// clear collected fees, which will now be distributed
 	k.feeCollectionKeeper.ClearCollectedFees(ctx)
 
-	// Update outstanding rewards
-	outstanding := k.GetOutstandingRewards(ctx)
-	outstanding = outstanding.Plus(feesCollected)
-	k.SetOutstandingRewards(ctx, outstanding)
-
-	// Temporary workaround to keep CanWithdrawInvariant happy.
-	// General discussions here: https://github.com/cosmos/cosmos-sdk/issues/2906#issuecomment-441867634
+	// temporary workaround to keep CanWithdrawInvariant happy.
+	// general discussions here: https://github.com/cosmos/cosmos-sdk/issues/2906#issuecomment-441867634
 	if totalPower == 0 {
 		feePool.CommunityPool = feePool.CommunityPool.Plus(feesCollected)
 		k.SetFeePool(ctx, feePool)
 		return
 	}
 
-	// Calculate fraction votes
+	// calculate fraction votes
 	fractionVotes := sdk.NewDec(sumPrecommitPower).Quo(sdk.NewDec(totalPower))
 
 	// calculate proposer reward
@@ -52,7 +47,8 @@ func (k Keeper) AllocateTokens(ctx sdk.Context, sumPrecommitPower int64, totalPo
 	for _, vote := range votes {
 		validator := k.stakeKeeper.ValidatorByConsAddr(ctx, vote.Validator.Address)
 
-		// TODO Likely we should only reward validators who actually signed the block.
+		// TODO likely we should only reward validators who actually signed the block.
+		// ref https://github.com/cosmos/cosmos-sdk/issues/2525#issuecomment-430838701
 		powerFraction := sdk.NewDec(vote.Validator.Power).Quo(sdk.NewDec(totalPower))
 		reward := feesCollected.MulDec(voteMultiplier).MulDec(powerFraction)
 		k.AllocateTokensToValidator(ctx, validator, reward)
@@ -61,6 +57,12 @@ func (k Keeper) AllocateTokens(ctx sdk.Context, sumPrecommitPower int64, totalPo
 
 	// allocate community funding
 	feePool.CommunityPool = feePool.CommunityPool.Plus(remaining)
+	k.SetFeePool(ctx, feePool)
+
+	// update outstanding rewards
+	outstanding := k.GetOutstandingRewards(ctx)
+	outstanding = outstanding.Plus(feesCollected.Minus(remaining))
+	k.SetOutstandingRewards(ctx, outstanding)
 
 }
 

x/distribution/keeper/calculation.go

@@ -7,16 +7,16 @@ import (
 )
 
 func (k Keeper) initializeValidator(ctx sdk.Context, val sdk.Validator) {
-	// Set initial historical rewards (period 0)
+	// set initial historical rewards (period 0)
 	k.setValidatorHistoricalRewards(ctx, val.GetOperator(), 0, types.ValidatorHistoricalRewards{})
 
-	// Set current rewards (starting at period 1)
+	// set current rewards (starting at period 1)
 	k.setValidatorCurrentRewards(ctx, val.GetOperator(), types.ValidatorCurrentRewards{
 		Rewards: sdk.DecCoins{},
 		Period:  1,
 	})
 
-	// Set accumulated commission
+	// set accumulated commission
 	k.setValidatorAccumulatedCommission(ctx, val.GetOperator(), types.ValidatorAccumulatedCommission{})
 }
 
@@ -28,8 +28,8 @@ func (k Keeper) incrementValidatorPeriod(ctx sdk.Context, val sdk.Validator) uin
 	var current sdk.DecCoins
 	if val.GetPower().IsZero() {
 		// this can happen after redelegations are slashed
+		// TODO add to the community pool?
 		current = sdk.DecCoins{}
-		// TODO: Add to the community pool?
 	} else {
 		current = rewards.Rewards.QuoDec(sdk.NewDecFromInt(val.GetPower()))
 	}
@@ -52,33 +52,81 @@ func (k Keeper) incrementValidatorPeriod(ctx sdk.Context, val sdk.Validator) uin
 
 func (k Keeper) initializeDelegation(ctx sdk.Context, val sdk.ValAddress, del sdk.AccAddress) {
 	period := k.GetValidatorCurrentRewards(ctx, val).Period
+	validator := k.stakeKeeper.Validator(ctx, val)
+	delegation := k.stakeKeeper.Delegation(ctx, del, val)
+	// TODO need to make sure this truncates instead of rounding
+	stake := delegation.GetShares().Mul(validator.GetDelegatorShareExRate())
 	k.setDelegatorStartingInfo(ctx, val, del, types.DelegatorStartingInfo{
-		PreviousPeriod: period,
-		Stake:          sdk.ZeroInt(),
+		PreviousPeriod: period - 1,
+		Stake:          stake,
+		Height:         uint64(ctx.BlockHeight()),
 	})
 }
 
+func (k Keeper) calculateDelegationRewardsBetween(ctx sdk.Context, val sdk.Validator, startingPeriod uint64, endingPeriod uint64, stake sdk.Dec) (rewards sdk.DecCoins) {
+	if startingPeriod > endingPeriod {
+		panic("ending period must be after starting period")
+	} else if startingPeriod == endingPeriod {
+		return
+	}
+	starting := k.GetValidatorHistoricalRewards(ctx, val.GetOperator(), startingPeriod)
+	ending := k.GetValidatorHistoricalRewards(ctx, val.GetOperator(), endingPeriod)
+	difference := ending.Minus(starting)
+	rewards = difference.MulDec(stake)
+	return
+}
+
 func (k Keeper) withdrawDelegationRewards(ctx sdk.Context, val sdk.Validator, del sdk.Delegation) sdk.Error {
-	endedPeriod := k.incrementValidatorPeriod(ctx, val)
-	present := k.GetValidatorHistoricalRewards(ctx, del.GetValidatorAddr(), endedPeriod)
+
+	endingPeriod := k.incrementValidatorPeriod(ctx, val)
+
 	startingInfo := k.GetDelegatorStartingInfo(ctx, del.GetValidatorAddr(), del.GetDelegatorAddr())
-	historical := k.GetValidatorHistoricalRewards(ctx, del.GetValidatorAddr(), startingInfo.PreviousPeriod)
-	difference := present.Minus(historical)
-	rewards := difference.MulDec(sdk.NewDecFromInt(startingInfo.Stake))
+	startingPeriod := startingInfo.PreviousPeriod
+	stake := startingInfo.Stake
+	rewards := sdk.DecCoins{}
+
+	// iterate through slashes and withdraw with calculated stake for sub-intervals
+	startingHeight := startingInfo.Height + 1
+	endingHeight := uint64(ctx.BlockHeight())
+	k.IterateValidatorSlashFractions(ctx, del.GetValidatorAddr(), startingHeight, endingHeight, func(height uint64, fraction types.ValidatorSlashFraction) (stop bool) {
+		stake = stake.Mul(sdk.OneDec().Sub(fraction.Fraction))
+		endingPeriod := fraction.ValidatorPeriod
+		rewards = rewards.Plus(k.calculateDelegationRewardsBetween(ctx, val, startingPeriod, endingPeriod, stake))
+		startingPeriod = endingPeriod
+		return false
+	})
 
-	// Truncate coins, return remainder to community pool
+	// calculate rewards for final period
+	rewards = rewards.Plus(k.calculateDelegationRewardsBetween(ctx, val, startingPeriod, endingPeriod, stake))
+
+	// truncate coins, return remainder to community pool
 	coins, remainder := rewards.TruncateDecimal()
 	outstanding := k.GetOutstandingRewards(ctx)
 	k.SetOutstandingRewards(ctx, outstanding.Minus(rewards))
 	feePool := k.GetFeePool(ctx)
 	feePool.CommunityPool = feePool.CommunityPool.Plus(remainder)
 	k.SetFeePool(ctx, feePool)
 
-	// Add coins to user account
+	// add coins to user account
 	withdrawAddr := k.GetDelegatorWithdrawAddr(ctx, del.GetDelegatorAddr())
 	if _, _, err := k.bankKeeper.AddCoins(ctx, withdrawAddr, coins); err != nil {
 		return err
 	}
 
 	return nil
 }
+
+func (k Keeper) updateValidatorSlashFraction(ctx sdk.Context, valAddr sdk.ValAddress, fraction sdk.Dec) {
+	height := uint64(ctx.BlockHeight())
+	currentFraction := sdk.ZeroDec()
+	currentPeriod := k.GetValidatorCurrentRewards(ctx, valAddr).Period
+	current, found := k.GetValidatorSlashFraction(ctx, valAddr, height)
+	if found {
+		currentFraction = current.Fraction
+	}
+	updatedFraction := sdk.OneDec().Sub(sdk.OneDec().Sub(currentFraction).Mul(sdk.OneDec().Sub(fraction)))
+	k.setValidatorSlashFraction(ctx, valAddr, height, types.ValidatorSlashFraction{
+		ValidatorPeriod: currentPeriod,
+		Fraction:        updatedFraction,
+	})
+}

x/distribution/keeper/hooks.go

@@ -20,6 +20,9 @@ func (h Hooks) OnValidatorCreated(ctx sdk.Context, valAddr sdk.ValAddress) {
 	h.k.initializeValidator(ctx, val)
 }
 func (h Hooks) OnValidatorModified(ctx sdk.Context, valAddr sdk.ValAddress) {
+	val := h.k.stakeKeeper.Validator(ctx, valAddr)
+	// increment period
+	h.k.incrementValidatorPeriod(ctx, val)
 }
 func (h Hooks) OnValidatorRemoved(ctx sdk.Context, _ sdk.ConsAddress, valAddr sdk.ValAddress) {
 }
@@ -28,9 +31,6 @@ func (h Hooks) OnDelegationCreated(ctx sdk.Context, delAddr sdk.AccAddress, valA
 
 	// increment period
 	h.k.incrementValidatorPeriod(ctx, val)
-
-	// create new delegation period record
-	h.k.initializeDelegation(ctx, valAddr, delAddr)
 }
 func (h Hooks) OnDelegationSharesModified(ctx sdk.Context, delAddr sdk.AccAddress, valAddr sdk.ValAddress) {
 	val := h.k.stakeKeeper.Validator(ctx, valAddr)
@@ -40,9 +40,6 @@ func (h Hooks) OnDelegationSharesModified(ctx sdk.Context, delAddr sdk.AccAddres
 	if err := h.k.withdrawDelegationRewards(ctx, val, del); err != nil {
 		panic(err)
 	}
-
-	// create new delegation period record
-	h.k.initializeDelegation(ctx, valAddr, delAddr)
 }
 func (h Hooks) OnDelegationRemoved(ctx sdk.Context, delAddr sdk.AccAddress, valAddr sdk.ValAddress) {
 	val := h.k.stakeKeeper.Validator(ctx, valAddr)
@@ -53,9 +50,16 @@ func (h Hooks) OnDelegationRemoved(ctx sdk.Context, delAddr sdk.AccAddress, valA
 		panic(err)
 	}
 }
+func (h Hooks) AfterDelegationModified(ctx sdk.Context, delAddr sdk.AccAddress, valAddr sdk.ValAddress) {
+	// create new delegation period record
+	h.k.initializeDelegation(ctx, valAddr, delAddr)
+}
 func (h Hooks) OnValidatorBeginUnbonding(ctx sdk.Context, _ sdk.ConsAddress, valAddr sdk.ValAddress) {
 }
 func (h Hooks) OnValidatorBonded(ctx sdk.Context, _ sdk.ConsAddress, valAddr sdk.ValAddress) {
 }
 func (h Hooks) OnValidatorPowerDidChange(ctx sdk.Context, _ sdk.ConsAddress, valAddr sdk.ValAddress) {
 }
+func (h Hooks) BeforeValidatorSlashed(ctx sdk.Context, valAddr sdk.ValAddress, fraction sdk.Dec) {
+	h.k.updateValidatorSlashFraction(ctx, valAddr, fraction)
+}

x/distribution/keeper/key.go

@@ -22,6 +22,7 @@ var (
 	ValidatorHistoricalRewardsPrefix     = []byte{0x05} // key for historical validators rewards / stake
 	ValidatorCurrentRewardsPrefix        = []byte{0x06} // key for current validator rewards
 	ValidatorAccumulatedCommissionPrefix = []byte{0x07} // key for accumulated validator commission
+	ValidatorSlashFractionPrefix         = []byte{0x08} // key for validator slash fraction
 
 	ParamStoreKeyCommunityTax        = []byte("communitytax")
 	ParamStoreKeyBaseProposerReward  = []byte("baseproposerreward")
@@ -42,6 +43,15 @@ func GetDelegatorWithdrawInfoAddress(key []byte) (delAddr sdk.AccAddress) {
 	return sdk.AccAddress(addr)
 }
 
+// gets the height from a validator's slash fraction key
+func GetValidatorSlashFractionHeight(key []byte) (height uint64) {
+	b := key[1+sdk.AddrLen:]
+	if len(b) != 8 {
+		panic("unexpected key length")
+	}
+	return binary.LittleEndian.Uint64(b)
+}
+
 // gets the key for a delegator's starting info
 func GetDelegatorStartingInfoKey(v sdk.ValAddress, d sdk.AccAddress) []byte {
 	return append(append(DelegatorStartingInfoPrefix, v.Bytes()...), d.Bytes()...)
@@ -63,3 +73,10 @@ func GetValidatorCurrentRewardsKey(v sdk.ValAddress) []byte {
 func GetValidatorAccumulatedCommissionKey(v sdk.ValAddress) []byte {
 	return append(ValidatorAccumulatedCommissionPrefix, v.Bytes()...)
 }
+
+// gets the key for a validator's slash fraction
+func GetValidatorSlashFractionKey(v sdk.ValAddress, height uint64) []byte {
+	b := make([]byte, 8)
+	binary.LittleEndian.PutUint64(b, height)
+	return append(append(ValidatorSlashFractionPrefix, v.Bytes()...), b...)
+}

x/distribution/keeper/params.go

@@ -5,7 +5,7 @@ import (
 	"github.com/cosmos/cosmos-sdk/x/params"
 )
 
-// Type declaration for parameters
+// type declaration for parameters
 func ParamTypeTable() params.TypeTable {
 	return params.NewTypeTable(
 		ParamStoreKeyCommunityTax, sdk.Dec{},
@@ -14,7 +14,7 @@ func ParamTypeTable() params.TypeTable {
 	)
 }
 
-// Returns the current CommunityTax rate from the global param store
+// returns the current CommunityTax rate from the global param store
 // nolint: errcheck
 func (k Keeper) GetCommunityTax(ctx sdk.Context) sdk.Dec {
 	var percent sdk.Dec
@@ -27,7 +27,7 @@ func (k Keeper) SetCommunityTax(ctx sdk.Context, percent sdk.Dec) {
 	k.paramSpace.Set(ctx, ParamStoreKeyCommunityTax, &percent)
 }
 
-// Returns the current BaseProposerReward rate from the global param store
+// returns the current BaseProposerReward rate from the global param store
 // nolint: errcheck
 func (k Keeper) GetBaseProposerReward(ctx sdk.Context) sdk.Dec {
 	var percent sdk.Dec
@@ -40,7 +40,7 @@ func (k Keeper) SetBaseProposerReward(ctx sdk.Context, percent sdk.Dec) {
 	k.paramSpace.Set(ctx, ParamStoreKeyBaseProposerReward, &percent)
 }
 
-// Returns the current BaseProposerReward rate from the global param store
+// returns the current BaseProposerReward rate from the global param store
 // nolint: errcheck
 func (k Keeper) GetBonusProposerReward(ctx sdk.Context) sdk.Dec {
 	var percent sdk.Dec