Files
prysm/beacon-chain/core/helpers/rewards_penalties.go
2019-06-18 17:22:39 -07:00

109 lines
3.3 KiB
Go

package helpers
import (
"fmt"
"github.com/prysmaticlabs/prysm/beacon-chain/cache"
pb "github.com/prysmaticlabs/prysm/proto/beacon/p2p/v1"
"github.com/prysmaticlabs/prysm/shared/params"
)
var totalBalanceCache = cache.NewTotalBalanceCache()
var totalActiveBalanceCache = cache.NewActiveBalanceCache()
// TotalBalance returns the total amount at stake in Gwei
// of input validators.
//
// Spec pseudocode definition:
// def get_total_balance(state: BeaconState, indices: List[ValidatorIndex]) -> Gwei:
// """
// Return the combined effective balance of the ``indices``. (1 Gwei minimum to avoid divisions by zero.)
// """
// return max(sum([state.validator_registry[index].effective_balance for index in indices]), 1)
func TotalBalance(state *pb.BeaconState, indices []uint64) (uint64, error) {
epoch := CurrentEpoch(state)
total, err := totalBalanceCache.TotalBalanceInEpoch(epoch)
if err != nil {
return 0, fmt.Errorf("could not retrieve total balance from cache: %v", err)
}
if total != params.BeaconConfig().FarFutureEpoch {
return total, nil
}
total = 0
for _, idx := range indices {
total += state.Validators[idx].EffectiveBalance
}
if err := totalBalanceCache.AddTotalBalance(&cache.TotalBalanceByEpoch{
Epoch: epoch,
TotalBalance: total,
}); err != nil {
return 0, fmt.Errorf("could not save total balance for cache: %v", err)
}
// Return 1 Gwei minimum to avoid divisions by zero
if total == 0 {
return 1, nil
}
return total, nil
}
// TotalActiveBalance returns the total amount at stake in Gwei
// of active validators.
func TotalActiveBalance(state *pb.BeaconState) (uint64, error) {
epoch := CurrentEpoch(state)
total, err := totalActiveBalanceCache.ActiveBalanceInEpoch(epoch)
if err != nil {
return 0, fmt.Errorf("could not retrieve total balance from cache: %v", err)
}
if total != params.BeaconConfig().FarFutureEpoch {
return total, nil
}
total = 0
for i, v := range state.Validators {
if IsActiveValidator(v, epoch) {
total += state.Validators[i].EffectiveBalance
}
}
if err := totalActiveBalanceCache.AddActiveBalance(&cache.ActiveBalanceByEpoch{
Epoch: epoch,
ActiveBalance: total,
}); err != nil {
return 0, fmt.Errorf("could not save active balance for cache: %v", err)
}
return total, nil
}
// IncreaseBalance increases validator with the given 'index' balance by 'delta' in Gwei.
//
// Spec pseudocode definition:
// def increase_balance(state: BeaconState, index: ValidatorIndex, delta: Gwei) -> None:
// """
// Increase validator balance by ``delta``.
// """
// state.balances[index] += delta
func IncreaseBalance(state *pb.BeaconState, idx uint64, delta uint64) *pb.BeaconState {
state.Balances[idx] += delta
return state
}
// DecreaseBalance decreases validator with the given 'index' balance by 'delta' in Gwei.
//
// Spec pseudocode definition:
// def decrease_balance(state: BeaconState, index: ValidatorIndex, delta: Gwei) -> None:
// """
// Decrease validator balance by ``delta`` with underflow protection.
// """
// state.balances[index] = 0 if delta > state.balances[index] else state.balances[index] - delta
func DecreaseBalance(state *pb.BeaconState, idx uint64, delta uint64) *pb.BeaconState {
if delta > state.Balances[idx] {
state.Balances[idx] = 0
return state
}
state.Balances[idx] -= delta
return state
}