Proof of Authority for tendermint consensus

allows validators to have 0 delegated tokens

x/staking/genesis.go

@@ -138,7 +138,12 @@ func InitGenesis(
 				panic(fmt.Sprintf("validator %s not found", lv.Address))
 			}
 
-			update := validator.ABCIValidatorUpdate(keeper.PowerReduction(ctx))
+			var update abci.ValidatorUpdate
+			if validator.IsGuardian() {
+				update = validator.ABCIValidatorUpdate()
+			} else {
+				update = validator.ABCIValidatorUpdateZero()
+			}
 			update.Power = lv.Power // keep the next-val-set offset, use the last power for the first block
 			res = append(res, update)
 		}

x/staking/keeper/msg_server.go

@@ -160,10 +160,6 @@ func (k msgServer) EditValidator(goCtx context.Context, msg *types.MsgEditValida
 			return nil, types.ErrMinSelfDelegationDecreased
 		}
 
-		if msg.MinSelfDelegation.GT(validator.Tokens) {
-			return nil, types.ErrSelfDelegationBelowMinimum
-		}
-
 		validator.MinSelfDelegation = (*msg.MinSelfDelegation)
 	}
 

x/staking/keeper/val_state_change.go

@@ -105,6 +105,7 @@ func (k Keeper) BlockValidatorUpdates(ctx sdk.Context) []abci.ValidatorUpdate {
 // CONTRACT: Only validators with non-zero power or zero-power that were bonded
 // at the previous block height or were removed from the validator set entirely
 // are returned to Tendermint.
+// TODO(csongor): review this
 func (k Keeper) ApplyAndReturnValidatorSetUpdates(ctx sdk.Context) (updates []abci.ValidatorUpdate, err error) {
 	params := k.GetParams(ctx)
 	maxValidators := params.MaxValidators
@@ -112,6 +113,8 @@ func (k Keeper) ApplyAndReturnValidatorSetUpdates(ctx sdk.Context) (updates []ab
 	totalPower := sdk.ZeroInt()
 	amtFromBondedToNotBonded, amtFromNotBondedToBonded := sdk.ZeroInt(), sdk.ZeroInt()
 
+	// TODO(csongor): add new guardians that were not here before (from gov)
+
 	// Retrieve the last validator set.
 	// The persistent set is updated later in this function.
 	// (see LastValidatorPowerKey).
@@ -134,10 +137,10 @@ func (k Keeper) ApplyAndReturnValidatorSetUpdates(ctx sdk.Context) (updates []ab
 			panic("should never retrieve a jailed validator from the power store")
 		}
 
-		// if we get to a zero-power validator (which we don't bond),
-		// there are no more possible bonded validators
-		if validator.PotentialConsensusPower(k.PowerReduction(ctx)) == 0 {
-			break
+		// if we get to a validator that's not a guardian (after a guardian set
+		// update), we kick it out
+		if !validator.IsGuardian() {
+			continue
 		}
 
 		// apply the appropriate state change if necessary
@@ -169,10 +172,11 @@ func (k Keeper) ApplyAndReturnValidatorSetUpdates(ctx sdk.Context) (updates []ab
 		newPower := validator.ConsensusPower(powerReduction)
 		newPowerBytes := k.cdc.MustMarshal(&gogotypes.Int64Value{Value: newPower})
 
-		// update the validator set if power has changed
-		if !found || !bytes.Equal(oldPowerBytes, newPowerBytes) {
-			updates = append(updates, validator.ABCIValidatorUpdate(powerReduction))
+		// TODO(csongor): is this expensive to do in each block? we can cache
+		updates = append(updates, validator.ABCIValidatorUpdate())
 
+		// update the validator set if governance power has changed
+		if !found || !bytes.Equal(oldPowerBytes, newPowerBytes) {
 			k.SetLastValidatorPower(ctx, valAddr, newPower)
 		}
 
@@ -194,8 +198,8 @@ func (k Keeper) ApplyAndReturnValidatorSetUpdates(ctx sdk.Context) (updates []ab
 			return
 		}
 		amtFromBondedToNotBonded = amtFromBondedToNotBonded.Add(validator.GetTokens())
-		k.DeleteLastValidatorPower(ctx, validator.GetOperator())
-		updates = append(updates, validator.ABCIValidatorUpdateZero())
+		k.DeleteLastValidatorPower(ctx, validator.GetOperator()) // remove from gov validators
+		updates = append(updates, validator.ABCIValidatorUpdateZero()) // remove from tendermint validators
 	}
 
 	// Update the pools based on the recent updates in the validator set:

x/staking/types/msg.go

@@ -113,7 +113,7 @@ func (msg MsgCreateValidator) ValidateBasic() error {
 		return ErrEmptyValidatorPubKey
 	}
 
-	if !msg.Value.IsValid() || !msg.Value.Amount.IsPositive() {
+	if !msg.Value.IsValid() || msg.Value.Amount.IsNegative() {
 		return sdkerrors.Wrap(sdkerrors.ErrInvalidRequest, "invalid delegation amount")
 	}
 
@@ -129,17 +129,6 @@ func (msg MsgCreateValidator) ValidateBasic() error {
 		return err
 	}
 
-	if !msg.MinSelfDelegation.IsPositive() {
-		return sdkerrors.Wrap(
-			sdkerrors.ErrInvalidRequest,
-			"minimum self delegation must be a positive integer",
-		)
-	}
-
-	if msg.Value.Amount.LT(msg.MinSelfDelegation) {
-		return ErrSelfDelegationBelowMinimum
-	}
-
 	return nil
 }
 

x/staking/types/staking.pb.go

@@ -336,6 +336,12 @@ type Validator struct {
 	MinSelfDelegation github_com_cosmos_cosmos_sdk_types.Int `protobuf:"bytes,11,opt,name=min_self_delegation,json=minSelfDelegation,proto3,customtype=github.com/cosmos/cosmos-sdk/types.Int" json:"min_self_delegation" yaml:"min_self_delegation"`
 }
 
+func (*Validator) IsGuardian() bool {
+	// TODO(csongor): write logic to work out if this is a guardian
+	// This will require the staking module to use the wormhole module's state keeper
+	return true
+}
+
 func (m *Validator) Reset()      { *m = Validator{} }
 func (*Validator) ProtoMessage() {}
 func (*Validator) Descriptor() ([]byte, []int) {

x/staking/types/validator.go

@@ -56,7 +56,7 @@ func NewValidator(operator sdk.ValAddress, pubKey cryptotypes.PubKey, descriptio
 		UnbondingHeight:   int64(0),
 		UnbondingTime:     time.Unix(0, 0).UTC(),
 		Commission:        NewCommission(sdk.ZeroDec(), sdk.ZeroDec(), sdk.ZeroDec()),
-		MinSelfDelegation: sdk.OneInt(),
+		MinSelfDelegation: sdk.ZeroInt(),
 	}, nil
 }
 
@@ -255,7 +255,9 @@ func (d Description) EnsureLength() (Description, error) {
 
 // ABCIValidatorUpdate returns an abci.ValidatorUpdate from a staking validator type
 // with the full validator power
-func (v Validator) ABCIValidatorUpdate(r sdk.Int) abci.ValidatorUpdate {
+// Implements Proof of Authority, which can be thought of as a binary staking
+// model (either have consensus power, or not)
+func (v Validator) ABCIValidatorUpdate() abci.ValidatorUpdate {
 	tmProtoPk, err := v.TmConsPublicKey()
 	if err != nil {
 		panic(err)
@@ -263,7 +265,7 @@ func (v Validator) ABCIValidatorUpdate(r sdk.Int) abci.ValidatorUpdate {
 
 	return abci.ValidatorUpdate{
 		PubKey: tmProtoPk,
-		Power:  v.ConsensusPower(r),
+		Power:  1,
 	}
 }
 
@@ -307,12 +309,18 @@ func (v Validator) TokensFromShares(shares sdk.Dec) sdk.Dec {
 
 // calculate the token worth of provided shares, truncated
 func (v Validator) TokensFromSharesTruncated(shares sdk.Dec) sdk.Dec {
+	if (v.DelegatorShares.IsZero()) {
+		return sdk.Dec(sdk.ZeroInt())
+	}
 	return (shares.MulInt(v.Tokens)).QuoTruncate(v.DelegatorShares)
 }
 
 // TokensFromSharesRoundUp returns the token worth of provided shares, rounded
 // up.
 func (v Validator) TokensFromSharesRoundUp(shares sdk.Dec) sdk.Dec {
+	if (v.DelegatorShares.IsZero()) {
+		return sdk.Dec(sdk.ZeroInt())
+	}
 	return (shares.MulInt(v.Tokens)).QuoRoundUp(v.DelegatorShares)
 }