[Stablestake]: Withdrawal limit (#1110)

* withdrawal limit

* fix

proto/elys/stablestake/params.proto

@@ -100,4 +100,9 @@ message Params {
     (gogoproto.customtype) = "cosmossdk.io/math.LegacyDec",
     (gogoproto.nullable) = false
   ];
+  string max_withdraw_ratio = 12 [
+    (cosmos_proto.scalar) = "cosmos.Dec",
+    (gogoproto.customtype) = "cosmossdk.io/math.LegacyDec",
+    (gogoproto.nullable) = false
+  ];
 }

x/stablestake/keeper/msg_server_unbond.go

@@ -37,7 +37,7 @@ func (k msgServer) Unbond(goCtx context.Context, msg *types.MsgUnbond) (*types.M
 	redemptionAmount := shareCoin.Amount.ToLegacyDec().Mul(redemptionRate).RoundInt()
 
 	amountAfterRedemption := params.TotalValue.Sub(redemptionAmount)
-	maxAllowed := (params.TotalValue.ToLegacyDec().Mul(params.MaxLeverageRatio)).TruncateInt()
+	maxAllowed := (params.TotalValue.ToLegacyDec().Mul(params.MaxWithdrawRatio)).TruncateInt()
 	if amountAfterRedemption.LT(maxAllowed) {
 		return nil, types.ErrInvalidWithdraw
 	}

x/stablestake/migrations/v8_migration.go

@@ -0,0 +1,13 @@
+package migrations
+
+import (
+	"cosmossdk.io/math"
+	sdk "github.com/cosmos/cosmos-sdk/types"
+)
+
+func (m Migrator) V8Migration(ctx sdk.Context) error {
+	params := m.keeper.GetParams(ctx)
+	params.MaxWithdrawRatio = math.LegacyMustNewDecFromStr("0.9")
+	m.keeper.SetParams(ctx, params)
+	return nil
+}

x/stablestake/module.go

@@ -120,7 +120,7 @@ func (am AppModule) RegisterServices(cfg module.Configurator) {
 	types.RegisterMsgServer(cfg.MsgServer(), keeper.NewMsgServerImpl(am.keeper))
 	types.RegisterQueryServer(cfg.QueryServer(), am.keeper)
 	m := migrations.NewMigrator(am.keeper)
-	err := cfg.RegisterMigration(types.ModuleName, 6, m.V7Migration)
+	err := cfg.RegisterMigration(types.ModuleName, 7, m.V8Migration)
 	if err != nil {
 		panic(err)
 	}
@@ -147,7 +147,7 @@ func (am AppModule) ExportGenesis(ctx sdk.Context, cdc codec.JSONCodec) json.Raw
 }
 
 // ConsensusVersion is a sequence number for state-breaking change of the module. It should be incremented on each consensus-breaking change introduced by the module. To avoid wrong/empty versions, the initial version should be set to 1
-func (AppModule) ConsensusVersion() uint64 { return 7 }
+func (AppModule) ConsensusVersion() uint64 { return 8 }
 
 // BeginBlock contains the logic that is automatically triggered at the beginning of each block
 func (am AppModule) BeginBlock(goCtx context.Context) error {

x/stablestake/types/params.go

@@ -2,6 +2,7 @@ package types
 
 import (
 	"fmt"
+
 	sdk "github.com/cosmos/cosmos-sdk/types"
 
 	"cosmossdk.io/math"
@@ -21,6 +22,7 @@ func DefaultParams() Params {
 		HealthGainFactor:     math.LegacyOneDec(),
 		TotalValue:           math.ZeroInt(),
 		MaxLeverageRatio:     math.LegacyMustNewDecFromStr("0.7"),
+		MaxWithdrawRatio:     math.LegacyMustNewDecFromStr("0.7"),
 	}
 }