Merge pull request #1 from fissionlabsio/x-distr-scrt-foundation-tax

Secret Foundation Tax

Author: assafmo

x/distribution/handler.go

@@ -107,7 +107,7 @@ func NewCommunityPoolSpendProposalHandler(k Keeper) govtypes.Handler {
 			return keeper.HandleCommunityPoolSpendProposal(ctx, k, c)
 
 		default:
-			return sdkerrors.Wrapf(sdkerrors.ErrUnknownRequest, "unrecognized distr proposal content type: %T", c)
+			return sdkerrors.Wrapf(sdkerrors.ErrUnknownRequest, "unrecognized %s proposal content type: %T", types.ModuleName, c)
 		}
 	}
 }

x/distribution/keeper/allocation.go

@@ -77,24 +77,48 @@ func (k Keeper) AllocateTokens(
 			previousProposer.String()))
 	}
 
-	// calculate fraction allocated to validators
 	communityTax := k.GetCommunityTax(ctx)
 	voteMultiplier := sdk.OneDec().Sub(proposerMultiplier).Sub(communityTax)
 
-	// allocate tokens proportionally to voting power
-	// TODO consider parallelizing later, ref https://github.com/enigmampc/cosmos-sdk/pull/3099#discussion_r246276376
+	foundationTax := k.GetSecretFoundationTax(ctx)
+	foundationTaxAddr := k.GetSecretFoundationAddr(ctx)
+
+	// only apply the secret foundation tax when the tax and address is non-zero
+	var foundationTaxSum sdk.DecCoins
+	if !foundationTax.IsZero() && !foundationTaxAddr.Empty() {
+		voteMultiplier = voteMultiplier.Sub(foundationTax)
+
+		foundationTaxSum = feesCollected.MulDecTruncate(foundationTax)
+		remaining = remaining.Sub(foundationTaxSum)
+	}
+
+	// allocate tokens proportionally to voting power minus any taxes
 	for _, vote := range previousVotes {
 		validator := k.stakingKeeper.ValidatorByConsAddr(ctx, vote.Validator.Address)
 
-		// TODO consider microslashing for missing votes.
-		// ref https://github.com/enigmampc/cosmos-sdk/issues/2525#issuecomment-430838701
 		powerFraction := sdk.NewDec(vote.Validator.Power).QuoTruncate(sdk.NewDec(totalPreviousPower))
 		reward := feesCollected.MulDecTruncate(voteMultiplier).MulDecTruncate(powerFraction)
+
+		// allocate tokens to the validator
 		k.AllocateTokensToValidator(ctx, validator, reward)
+
+		// update the remaining allocation for the community pool
 		remaining = remaining.Sub(reward)
 	}
 
-	// allocate community funding
+	// Send the foundation tax sum to the foundation tax address. Note, the taxes
+	// collected are decimals and when coverted to integer coins, we must truncate.
+	// The remainder is given back to the community pool.
+	if !foundationTaxSum.IsZero() {
+		foundationTaxSumTrunc, rem := foundationTaxSum.TruncateDecimal()
+		remaining = remaining.Add(rem...)
+
+		if err := k.supplyKeeper.SendCoinsFromModuleToAccount(ctx, types.ModuleName, foundationTaxAddr, foundationTaxSumTrunc); err != nil {
+			panic(err)
+		}
+	}
+
+	// allocate community funding minus the foundation tax
 	feePool.CommunityPool = feePool.CommunityPool.Add(remaining...)
 	k.SetFeePool(ctx, feePool)
 }

x/distribution/keeper/params.go

@@ -41,3 +41,15 @@ func (k Keeper) GetWithdrawAddrEnabled(ctx sdk.Context) (enabled bool) {
 	k.paramSpace.Get(ctx, types.ParamStoreKeyWithdrawAddrEnabled, &enabled)
 	return enabled
 }
+
+// GetSecretFoundationTax returns the current secret foundation tax.
+func (k Keeper) GetSecretFoundationTax(ctx sdk.Context) (tax sdk.Dec) {
+	k.paramSpace.Get(ctx, types.ParamSecretFoundationTax, &tax)
+	return tax
+}
+
+// GetSecretFoundationAddr returns the current secret foundation address.
+func (k Keeper) GetSecretFoundationAddr(ctx sdk.Context) (addr sdk.AccAddress) {
+	k.paramSpace.Get(ctx, types.ParamSecretFoundationAddress, &addr)
+	return addr
+}

x/distribution/simulation/genesis.go

@@ -11,6 +11,7 @@ import (
 	sdk "github.com/enigmampc/cosmos-sdk/types"
 	"github.com/enigmampc/cosmos-sdk/types/module"
 	"github.com/enigmampc/cosmos-sdk/x/distribution/types"
+	"github.com/enigmampc/cosmos-sdk/x/simulation"
 )
 
 // Simulation parameter constants
@@ -19,6 +20,7 @@ const (
 	BaseProposerReward  = "base_proposer_reward"
 	BonusProposerReward = "bonus_proposer_reward"
 	WithdrawEnabled     = "withdraw_enabled"
+	FoundationTax       = "foundation_tax"
 )
 
 // GenCommunityTax randomized CommunityTax
@@ -41,6 +43,11 @@ func GenWithdrawEnabled(r *rand.Rand) bool {
 	return r.Int63n(101) <= 95 // 95% chance of withdraws being enabled
 }
 
+// GenSecretFoundationTax returns a randomized secret foundation tax parameter.
+func GenSecretFoundationTax(r *rand.Rand) sdk.Dec {
+	return sdk.NewDecWithPrec(1, 2).Add(sdk.NewDecWithPrec(int64(r.Intn(30)), 2))
+}
+
 // RandomizedGenState generates a random GenesisState for distribution
 func RandomizedGenState(simState *module.SimulationState) {
 	var communityTax sdk.Dec
@@ -67,13 +74,23 @@ func RandomizedGenState(simState *module.SimulationState) {
 		func(r *rand.Rand) { withdrawEnabled = GenWithdrawEnabled(r) },
 	)
 
+	var foundationTax sdk.Dec
+	simState.AppParams.GetOrGenerate(
+		simState.Cdc, FoundationTax, &foundationTax, simState.Rand,
+		func(r *rand.Rand) { foundationTax = GenSecretFoundationTax(r) },
+	)
+
+	foundationTaxAcc, _ := simulation.RandomAcc(simState.Rand, simState.Accounts)
+
 	distrGenesis := types.GenesisState{
 		FeePool: types.InitialFeePool(),
 		Params: types.Params{
-			CommunityTax:        communityTax,
-			BaseProposerReward:  baseProposerReward,
-			BonusProposerReward: bonusProposerReward,
-			WithdrawAddrEnabled: withdrawEnabled,
+			CommunityTax:            communityTax,
+			SecretFoundationTax:     foundationTax,
+			SecretFoundationAddress: foundationTaxAcc.Address,
+			BaseProposerReward:      baseProposerReward,
+			BonusProposerReward:     bonusProposerReward,
+			WithdrawAddrEnabled:     withdrawEnabled,
 		},
 	}
 

x/distribution/simulation/params.go

@@ -14,17 +14,23 @@ const (
 	keyCommunityTax        = "communitytax"
 	keyBaseProposerReward  = "baseproposerreward"
 	keyBonusProposerReward = "bonusproposerreward"
+	keySecretFoundationTax = "secretfoundationtax"
 )
 
-// ParamChanges defines the parameters that can be modified by param change proposals
-// on the simulation
+// ParamChanges defines the parameters that can be modified by param change
+// proposals in simulations.
 func ParamChanges(r *rand.Rand) []simulation.ParamChange {
 	return []simulation.ParamChange{
 		simulation.NewSimParamChange(types.ModuleName, keyCommunityTax,
 			func(r *rand.Rand) string {
 				return fmt.Sprintf("\"%s\"", GenCommunityTax(r))
 			},
 		),
+		simulation.NewSimParamChange(types.ModuleName, keySecretFoundationTax,
+			func(r *rand.Rand) string {
+				return fmt.Sprintf("\"%s\"", GenSecretFoundationTax(r))
+			},
+		),
 		simulation.NewSimParamChange(types.ModuleName, keyBaseProposerReward,
 			func(r *rand.Rand) string {
 				return fmt.Sprintf("\"%s\"", GenBaseProposerReward(r))

x/distribution/types/genesis.go

@@ -66,9 +66,16 @@ type GenesisState struct {
 }
 
 func NewGenesisState(
-	params Params, fp FeePool, dwis []DelegatorWithdrawInfo, pp sdk.ConsAddress, r []ValidatorOutstandingRewardsRecord,
-	acc []ValidatorAccumulatedCommissionRecord, historical []ValidatorHistoricalRewardsRecord,
-	cur []ValidatorCurrentRewardsRecord, dels []DelegatorStartingInfoRecord, slashes []ValidatorSlashEventRecord,
+	params Params,
+	fp FeePool,
+	dwis []DelegatorWithdrawInfo,
+	pp sdk.ConsAddress,
+	r []ValidatorOutstandingRewardsRecord,
+	acc []ValidatorAccumulatedCommissionRecord,
+	historical []ValidatorHistoricalRewardsRecord,
+	cur []ValidatorCurrentRewardsRecord,
+	dels []DelegatorStartingInfoRecord,
+	slashes []ValidatorSlashEventRecord,
 ) GenesisState {
 
 	return GenesisState{

x/distribution/types/params.go

@@ -20,14 +20,18 @@ var (
 	ParamStoreKeyBaseProposerReward  = []byte("baseproposerreward")
 	ParamStoreKeyBonusProposerReward = []byte("bonusproposerreward")
 	ParamStoreKeyWithdrawAddrEnabled = []byte("withdrawaddrenabled")
+	ParamSecretFoundationTax         = []byte("secretfoundationtax")
+	ParamSecretFoundationAddress     = []byte("secretfoundationaddress")
 )
 
 // Params defines the set of distribution parameters.
 type Params struct {
-	CommunityTax        sdk.Dec `json:"community_tax" yaml:"community_tax"`
-	BaseProposerReward  sdk.Dec `json:"base_proposer_reward" yaml:"base_proposer_reward"`
-	BonusProposerReward sdk.Dec `json:"bonus_proposer_reward" yaml:"bonus_proposer_reward"`
-	WithdrawAddrEnabled bool    `json:"withdraw_addr_enabled" yaml:"withdraw_addr_enabled"`
+	CommunityTax            sdk.Dec        `json:"community_tax" yaml:"community_tax"`
+	BaseProposerReward      sdk.Dec        `json:"base_proposer_reward" yaml:"base_proposer_reward"`
+	BonusProposerReward     sdk.Dec        `json:"bonus_proposer_reward" yaml:"bonus_proposer_reward"`
+	WithdrawAddrEnabled     bool           `json:"withdraw_addr_enabled" yaml:"withdraw_addr_enabled"`
+	SecretFoundationTax     sdk.Dec        `json:"secret_foundation_tax" yaml:"secret_foundation_tax"`
+	SecretFoundationAddress sdk.AccAddress `json:"secret_foundation_address" yaml:"secret_foundation_address"`
 }
 
 // ParamKeyTable returns the parameter key table.
@@ -38,10 +42,12 @@ func ParamKeyTable() params.KeyTable {
 // DefaultParams returns default distribution parameters
 func DefaultParams() Params {
 	return Params{
-		CommunityTax:        sdk.NewDecWithPrec(2, 2), // 2%
-		BaseProposerReward:  sdk.NewDecWithPrec(1, 2), // 1%
-		BonusProposerReward: sdk.NewDecWithPrec(4, 2), // 4%
-		WithdrawAddrEnabled: true,
+		CommunityTax:            sdk.NewDecWithPrec(2, 2), // 2%
+		SecretFoundationTax:     sdk.ZeroDec(),            // 0%
+		SecretFoundationAddress: sdk.AccAddress{},
+		BaseProposerReward:      sdk.NewDecWithPrec(1, 2), // 1%
+		BonusProposerReward:     sdk.NewDecWithPrec(4, 2), // 4%
+		WithdrawAddrEnabled:     true,
 	}
 }
 
@@ -57,6 +63,8 @@ func (p *Params) ParamSetPairs() params.ParamSetPairs {
 		params.NewParamSetPair(ParamStoreKeyBaseProposerReward, &p.BaseProposerReward, validateBaseProposerReward),
 		params.NewParamSetPair(ParamStoreKeyBonusProposerReward, &p.BonusProposerReward, validateBonusProposerReward),
 		params.NewParamSetPair(ParamStoreKeyWithdrawAddrEnabled, &p.WithdrawAddrEnabled, validateWithdrawAddrEnabled),
+		params.NewParamSetPair(ParamSecretFoundationTax, &p.SecretFoundationTax, validateSecretFoundationTax),
+		params.NewParamSetPair(ParamSecretFoundationAddress, &p.SecretFoundationAddress, validateSecretFoundationAddress),
 	}
 }
 
@@ -67,6 +75,11 @@ func (p Params) ValidateBasic() error {
 			"community tax should non-negative and less than one: %s", p.CommunityTax,
 		)
 	}
+	if p.SecretFoundationTax.IsNegative() || p.SecretFoundationTax.GT(sdk.OneDec()) {
+		return fmt.Errorf(
+			"secret foundation tax should non-negative and less than one: %s", p.SecretFoundationTax,
+		)
+	}
 	if p.BaseProposerReward.IsNegative() {
 		return fmt.Errorf(
 			"base proposer reward should be positive: %s", p.BaseProposerReward,
@@ -105,6 +118,38 @@ func validateCommunityTax(i interface{}) error {
 	return nil
 }
 
+func validateSecretFoundationTax(i interface{}) error {
+	v, ok := i.(sdk.Dec)
+	if !ok {
+		return fmt.Errorf("invalid parameter type: %T", i)
+	}
+
+	if v.IsNil() {
+		return fmt.Errorf("secret foundation tax must be not nil")
+	}
+	if v.IsNegative() {
+		return fmt.Errorf("secret foundation tax must be positive: %s", v)
+	}
+	if v.GT(sdk.OneDec()) {
+		return fmt.Errorf("secret foundation tax too large: %s", v)
+	}
+
+	return nil
+}
+
+func validateSecretFoundationAddress(i interface{}) error {
+	v, ok := i.(sdk.AccAddress)
+	if !ok {
+		return fmt.Errorf("invalid parameter type: %T", i)
+	}
+
+	if !v.Empty() {
+		return sdk.VerifyAddressFormat(v)
+	}
+
+	return nil
+}
+
 func validateBaseProposerReward(i interface{}) error {
 	v, ok := i.(sdk.Dec)
 	if !ok {