cosmos-sdk/x/stake/keeper/inflation.go

54 lines
1.7 KiB
Go

package keeper
import (
sdk "github.com/cosmos/cosmos-sdk/types"
"github.com/cosmos/cosmos-sdk/x/stake/types"
)
const (
hrsPerYr = 8766 // as defined by a julian year of 365.25 days
precision = 100000000000 // increased to this precision for accuracy
)
var hrsPerYrRat = sdk.NewRat(hrsPerYr)
// process provisions for an hour period
func (k Keeper) ProcessProvisions(ctx sdk.Context) types.Pool {
pool := k.GetPool(ctx)
pool.Inflation = k.NextInflation(ctx)
provisions := pool.Inflation.Mul(sdk.NewRat(pool.TokenSupply())).Quo(hrsPerYrRat).Evaluate()
// TODO add to the fees provisions
pool.LooseTokens += provisions
return pool
}
// get the next inflation rate for the hour
func (k Keeper) NextInflation(ctx sdk.Context) (inflation sdk.Rat) {
params := k.GetParams(ctx)
pool := k.GetPool(ctx)
// The target annual inflation rate is recalculated for each previsions cycle. The
// inflation is also subject to a rate change (positive or negative) depending on
// the distance from the desired ratio (67%). The maximum rate change possible is
// defined to be 13% per year, however the annual inflation is capped as between
// 7% and 20%.
// (1 - bondedRatio/GoalBonded) * InflationRateChange
inflationRateChangePerYear := sdk.OneRat().Sub(pool.BondedRatio().Quo(params.GoalBonded)).Mul(params.InflationRateChange)
inflationRateChange := inflationRateChangePerYear.Quo(hrsPerYrRat)
// increase the new annual inflation for this next cycle
inflation = pool.Inflation.Add(inflationRateChange)
if inflation.GT(params.InflationMax) {
inflation = params.InflationMax
}
if inflation.LT(params.InflationMin) {
inflation = params.InflationMin
}
return inflation.Round(precision)
}