0g-chain/chaincfg/mint.go
Solovyov1796 ee61e39769 Merge pull request #34 from 0glabs/vesting
calc inflation based on staking apy
2024-06-17 11:02:26 +08:00

77 lines
2.4 KiB
Go

package chaincfg
import (
"github.com/shopspring/decimal"
sdk "github.com/cosmos/cosmos-sdk/types"
minttypes "github.com/cosmos/cosmos-sdk/x/mint/types"
)
var (
Xmax, _ = sdk.NewDecFromStr("1.0") // upper limit on staked supply (as % of circ supply)
Ymin, _ = sdk.NewDecFromStr("0.05") // target APY at upper limit
Xmin, _ = sdk.NewDecFromStr("0.2") // lower limit on staked supply (as % of circ supply)
Ymax, _ = sdk.NewDecFromStr("0.15") // target APY at lower limit
decayRate, _ = sdk.NewDecFromStr("10")
)
func decExp(x sdk.Dec) sdk.Dec {
xDec := decimal.NewFromBigInt(x.BigInt(), -18)
expDec, _ := xDec.ExpTaylor(18)
expInt := expDec.Shift(18).BigInt()
return sdk.NewDecFromBigIntWithPrec(expInt, 18)
}
func NextInflationRate(ctx sdk.Context, minter minttypes.Minter, params minttypes.Params, bondedRatio sdk.Dec, circulatingRatio sdk.Dec) sdk.Dec {
X := bondedRatio.Quo(circulatingRatio)
var apy sdk.Dec
if X.LT(Xmin) {
apy = Ymax
} else {
exp := decayRate.Neg().Mul(Xmax.Sub(Xmin))
c := decExp(exp)
d := Ymin.Sub(Ymax.Mul(c)).Quo(sdk.OneDec().Sub(c))
expBonded := decayRate.Neg().Mul(X.Sub(Xmin))
cBonded := decExp(expBonded)
e := Ymax.Sub(d).Mul(cBonded)
apy = d.Add(e)
}
inflation := apy.Mul(bondedRatio)
// // 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.OneDec().
// Sub(bondedRatio.Quo(params.GoalBonded)).
// Mul(params.InflationRateChange)
// inflationRateChange := inflationRateChangePerYear.Quo(sdk.NewDec(int64(params.BlocksPerYear)))
// // adjust the new annual inflation for this next cycle
// inflation := minter.Inflation.Add(inflationRateChange) // note inflationRateChange may be negative
// if inflation.GT(params.InflationMax) {
// inflation = params.InflationMax
// }
// if inflation.LT(params.InflationMin) {
// inflation = params.InflationMin
// }
ctx.Logger().Info(
"nextInflationRate",
"bondedRatio", bondedRatio,
"circulatingRatio", circulatingRatio,
"apy", apy,
"inflation", inflation,
"params", params,
"minter", minter,
)
return inflation
}