package keeper import ( "time" sdk "github.com/cosmos/cosmos-sdk/types" "github.com/kava-labs/kava/x/kavadist/types" ) // MintPeriodInflation mints new tokens according to the inflation schedule specified in the parameters func (k Keeper) MintPeriodInflation(ctx sdk.Context) error { params := k.GetParams(ctx) if !params.Active { ctx.EventManager().EmitEvent( sdk.NewEvent( types.EventTypeKavaDist, sdk.NewAttribute(types.AttributeKeyStatus, types.AttributeValueInactive), ), ) return nil } previousBlockTime, found := k.GetPreviousBlockTime(ctx) if !found { previousBlockTime = ctx.BlockTime() k.SetPreviousBlockTime(ctx, previousBlockTime) return nil } err := k.mintIncentivePeriods(ctx, params.Periods, previousBlockTime) if err != nil { return err } coinsToDistribute, timeElapsed, err := k.mintInfrastructurePeriods(ctx, params.InfrastructureParams.InfrastructurePeriods, previousBlockTime) if err != nil { return err } err = k.distributeInfrastructureCoins(ctx, params.InfrastructureParams.PartnerRewards, params.InfrastructureParams.CoreRewards, timeElapsed, coinsToDistribute) if err != nil { return err } k.SetPreviousBlockTime(ctx, ctx.BlockTime()) return nil } func (k Keeper) mintIncentivePeriods(ctx sdk.Context, periods types.Periods, previousBlockTime time.Time) error { var err error for _, period := range periods { switch { // Case 1 - period is fully expired case period.End.Before(previousBlockTime): continue // Case 2 - period has ended since the previous block time case period.End.After(previousBlockTime) && (period.End.Before(ctx.BlockTime()) || period.End.Equal(ctx.BlockTime())): // calculate time elapsed relative to the periods end time timeElapsed := sdk.NewInt(period.End.Unix() - previousBlockTime.Unix()) _, err = k.mintInflationaryCoins(ctx, period.Inflation, timeElapsed, types.GovDenom) // update the value of previousBlockTime so that the next period starts from the end of the last // period and not the original value of previousBlockTime previousBlockTime = period.End // Case 3 - period is ongoing case (period.Start.Before(previousBlockTime) || period.Start.Equal(previousBlockTime)) && period.End.After(ctx.BlockTime()): // calculate time elapsed relative to the current block time timeElapsed := sdk.NewInt(ctx.BlockTime().Unix() - previousBlockTime.Unix()) _, err = k.mintInflationaryCoins(ctx, period.Inflation, timeElapsed, types.GovDenom) // Case 4 - period hasn't started case period.Start.After(ctx.BlockTime()) || period.Start.Equal(ctx.BlockTime()): continue } if err != nil { return err } } return nil } func (k Keeper) mintInflationaryCoins(ctx sdk.Context, inflationRate sdk.Dec, timePeriods sdk.Int, denom string) (sdk.Coin, error) { totalSupply := k.bankKeeper.GetSupply(ctx, denom) // used to scale accumulator calculations by 10^18 scalar := sdk.NewInt(1000000000000000000) // convert inflation rate to integer inflationInt := sdk.NewUintFromBigInt(inflationRate.Mul(sdk.NewDecFromInt(scalar)).TruncateInt().BigInt()) timePeriodsUint := sdk.NewUintFromBigInt(timePeriods.BigInt()) scalarUint := sdk.NewUintFromBigInt(scalar.BigInt()) // calculate the multiplier (amount to multiply the total supply by to achieve the desired inflation) // multiply the result by 10^-18 because RelativePow returns the result scaled by 10^18 accumulator := sdk.NewDecFromBigInt(sdk.RelativePow(inflationInt, timePeriodsUint, scalarUint).BigInt()).Mul(sdk.SmallestDec()) // calculate the number of coins to mint amountToMint := (sdk.NewDecFromInt(totalSupply.Amount).Mul(accumulator)).Sub(sdk.NewDecFromInt(totalSupply.Amount)).TruncateInt() if amountToMint.IsZero() { return sdk.Coin{}, nil } err := k.bankKeeper.MintCoins(ctx, types.KavaDistMacc, sdk.NewCoins(sdk.NewCoin(denom, amountToMint))) if err != nil { return sdk.Coin{}, err } ctx.EventManager().EmitEvent( sdk.NewEvent( types.EventTypeKavaDist, sdk.NewAttribute(types.AttributeKeyInflation, sdk.NewCoin(denom, amountToMint).String()), ), ) return sdk.NewCoin(denom, amountToMint), nil }