You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
136 lines
3.7 KiB
136 lines
3.7 KiB
package apr
|
|
|
|
import (
|
|
"github.com/harmony-one/harmony/core/types"
|
|
"github.com/harmony-one/harmony/shard"
|
|
"math/big"
|
|
|
|
"github.com/ethereum/go-ethereum/common"
|
|
"github.com/harmony-one/harmony/block"
|
|
"github.com/harmony-one/harmony/internal/params"
|
|
"github.com/harmony-one/harmony/internal/utils"
|
|
"github.com/harmony-one/harmony/numeric"
|
|
staking "github.com/harmony-one/harmony/staking/types"
|
|
"github.com/pkg/errors"
|
|
)
|
|
|
|
// Reader ..
|
|
type Reader interface {
|
|
GetHeaderByNumber(number uint64) *block.Header
|
|
Config() *params.ChainConfig
|
|
GetHeaderByHash(hash common.Hash) *block.Header
|
|
// GetHeader retrieves a block header from the database by hash and number.
|
|
GetHeader(hash common.Hash, number uint64) *block.Header
|
|
CurrentHeader() *block.Header
|
|
ReadValidatorSnapshotAtEpoch(
|
|
epoch *big.Int,
|
|
addr common.Address,
|
|
) (*staking.ValidatorWrapper, error)
|
|
}
|
|
|
|
const (
|
|
secondsInYear = int64(31557600)
|
|
)
|
|
|
|
var (
|
|
oneYear = big.NewInt(int64(secondsInYear))
|
|
)
|
|
|
|
func expectedRewardPerYear(
|
|
now, oneEpochAgo *block.Header,
|
|
curValidator, snapshotLastEpoch *staking.ValidatorWrapper,
|
|
) (*big.Int, error) {
|
|
timeNow, oneTAgo := now.Time(), oneEpochAgo.Time()
|
|
diffTime, diffReward :=
|
|
new(big.Int).Sub(timeNow, oneTAgo),
|
|
new(big.Int).Sub(curValidator.BlockReward, snapshotLastEpoch.BlockReward)
|
|
|
|
// impossibility but keep sane
|
|
if diffTime.Sign() == -1 {
|
|
return nil, errors.New("time stamp diff cannot be negative")
|
|
}
|
|
if diffTime.Cmp(common.Big0) == 0 {
|
|
return nil, errors.New("cannot div by zero of diff in time")
|
|
}
|
|
|
|
// TODO some more sanity checks of some sort?
|
|
expectedValue := new(big.Int).Div(diffReward, diffTime)
|
|
expectedPerYear := new(big.Int).Mul(expectedValue, oneYear)
|
|
utils.Logger().Info().Interface("now", curValidator).Interface("before", snapshotLastEpoch).
|
|
Uint64("diff-reward", diffReward.Uint64()).
|
|
Uint64("diff-time", diffTime.Uint64()).
|
|
Interface("expected-value", expectedValue).
|
|
Interface("expected-per-year", expectedPerYear).
|
|
Msg("expected reward per year computed")
|
|
return expectedPerYear, nil
|
|
}
|
|
|
|
var (
|
|
zero = numeric.ZeroDec()
|
|
)
|
|
|
|
// ComputeForValidator ..
|
|
func ComputeForValidator(
|
|
bc Reader,
|
|
block *types.Block,
|
|
validatorNow *staking.ValidatorWrapper,
|
|
) (*numeric.Dec, error) {
|
|
oneEpochAgo, zero :=
|
|
new(big.Int).Sub(block.Epoch(), common.Big1),
|
|
numeric.ZeroDec()
|
|
|
|
utils.Logger().Debug().
|
|
Uint64("now", block.Epoch().Uint64()).
|
|
Uint64("one-epoch-ago", oneEpochAgo.Uint64()).
|
|
Msg("apr - begin compute for validator ")
|
|
|
|
oneSnapshotAgo, err := bc.ReadValidatorSnapshotAtEpoch(
|
|
oneEpochAgo,
|
|
validatorNow.Address,
|
|
)
|
|
|
|
if err != nil {
|
|
return &zero, err
|
|
}
|
|
|
|
blockNumAtOneEpochAgo := shard.Schedule.EpochLastBlock(oneEpochAgo.Uint64())
|
|
|
|
headerOneEpochAgo := bc.GetHeaderByNumber(blockNumAtOneEpochAgo)
|
|
if block.Header() == nil || headerOneEpochAgo == nil {
|
|
utils.Logger().Debug().
|
|
Msgf("apr compute headers epochs ago %+v %+v %+v",
|
|
oneEpochAgo,
|
|
blockNumAtOneEpochAgo,
|
|
headerOneEpochAgo,
|
|
)
|
|
return &zero, errors.New("can't get headers for APR computation")
|
|
}
|
|
|
|
utils.Logger().Debug().
|
|
RawJSON("current-epoch-header", []byte(bc.CurrentHeader().String())).
|
|
RawJSON("one-epoch-ago-header", []byte(headerOneEpochAgo.String())).
|
|
Msg("headers used for apr computation")
|
|
|
|
estimatedRewardPerYear, err := expectedRewardPerYear(
|
|
block.Header(), headerOneEpochAgo,
|
|
validatorNow, oneSnapshotAgo,
|
|
)
|
|
|
|
if err != nil {
|
|
return nil, err
|
|
}
|
|
|
|
if estimatedRewardPerYear.Cmp(common.Big0) == 0 {
|
|
return &zero, nil
|
|
}
|
|
|
|
total := numeric.NewDecFromBigInt(validatorNow.TotalDelegation())
|
|
if total.IsZero() {
|
|
return nil, errors.New("zero total delegation will cause div by zero")
|
|
}
|
|
|
|
result := numeric.NewDecFromBigInt(estimatedRewardPerYear).Quo(
|
|
total,
|
|
)
|
|
return &result, nil
|
|
}
|
|
|