cosmos-sdk/x/stake/tick.go

76 lines
2.4 KiB
Go

package stake
import (
sdk "github.com/cosmos/cosmos-sdk/types"
abci "github.com/tendermint/abci/types"
)
// Tick - called at the end of every block
func Tick(ctx sdk.Context, m Mapper) (change []*abci.Validator, err error) {
// retrieve params
params := m.loadParams()
gs := m.loadGlobalState()
height := ctx.BlockHeight()
// Process Validator Provisions
// XXX right now just process every 5 blocks, in new SDK make hourly
if gs.InflationLastTime+5 <= height {
gs.InflationLastTime = height
processProvisions(m, gs, params)
}
newVals := m.getValidators(params.MaxVals)
// XXX determine change from old validators, set to change
_ = newVals
return change, nil
}
var hrsPerYr = sdk.NewRat(8766) // as defined by a julian year of 365.25 days
// process provisions for an hour period
func processProvisions(m Mapper, gs *GlobalState, params Params) {
gs.Inflation = nextInflation(gs, params).Round(1000000000)
// Because the validators hold a relative bonded share (`GlobalStakeShare`), when
// more bonded tokens are added proportionally to all validators the only term
// which needs to be updated is the `BondedPool`. So for each previsions cycle:
provisions := gs.Inflation.Mul(sdk.NewRat(gs.TotalSupply)).Quo(hrsPerYr).Evaluate()
gs.BondedPool += provisions
gs.TotalSupply += provisions
// XXX XXX XXX XXX XXX XXX XXX XXX XXX
// XXX Mint them to the hold account
// XXX XXX XXX XXX XXX XXX XXX XXX XXX
// save the params
m.saveGlobalState(gs)
}
// get the next inflation rate for the hour
func nextInflation(gs *GlobalState, params Params) (inflation sdk.Rat) {
// The target annual inflation rate is recalculated for each previsions cycle. The
// inflation is also subject to a rate change (positive of negative) depending or
// 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(gs.bondedRatio().Quo(params.GoalBonded)).Mul(params.InflationRateChange)
inflationRateChange := inflationRateChangePerYear.Quo(hrsPerYr)
// increase the new annual inflation for this next cycle
inflation = gs.Inflation.Add(inflationRateChange)
if inflation.GT(params.InflationMax) {
inflation = params.InflationMax
}
if inflation.LT(params.InflationMin) {
inflation = params.InflationMin
}
return
}