prysm-pulse/beacon-chain/core/epoch/epoch_processing.go
Raul Jordan 84916672c6
Remove Eth2-Types Dependency in Prysm (#10578)
* replace eth2 types

* replace protos

* regen proto

* replace

* gaz

* deps

* amend

* regen proto

* mod

* gaz

* gaz

* ensure build

* ssz

* add dep

* no more eth2 types

* no more eth2

* remg

* all builds

* buidl

* tidy

* clean

* fmt

* val serv

* gaz

Co-authored-by: Preston Van Loon <preston@prysmaticlabs.com>
2022-04-29 10:32:11 -04:00

481 lines
18 KiB
Go

// Package epoch contains epoch processing libraries according to spec, able to
// process new balance for validators, justify and finalize new
// check points, and shuffle validators to different slots and
// shards.
package epoch
import (
"context"
"fmt"
"sort"
"github.com/pkg/errors"
"github.com/prysmaticlabs/prysm/beacon-chain/core/helpers"
"github.com/prysmaticlabs/prysm/beacon-chain/core/time"
"github.com/prysmaticlabs/prysm/beacon-chain/core/validators"
"github.com/prysmaticlabs/prysm/beacon-chain/state"
"github.com/prysmaticlabs/prysm/config/params"
types "github.com/prysmaticlabs/prysm/consensus-types/primitives"
"github.com/prysmaticlabs/prysm/math"
ethpb "github.com/prysmaticlabs/prysm/proto/prysm/v1alpha1"
"github.com/prysmaticlabs/prysm/proto/prysm/v1alpha1/attestation"
)
// sortableIndices implements the Sort interface to sort newly activated validator indices
// by activation epoch and by index number.
type sortableIndices struct {
indices []types.ValidatorIndex
validators []*ethpb.Validator
}
// Len is the number of elements in the collection.
func (s sortableIndices) Len() int { return len(s.indices) }
// Swap swaps the elements with indexes i and j.
func (s sortableIndices) Swap(i, j int) { s.indices[i], s.indices[j] = s.indices[j], s.indices[i] }
// Less reports whether the element with index i must sort before the element with index j.
func (s sortableIndices) Less(i, j int) bool {
if s.validators[s.indices[i]].ActivationEligibilityEpoch == s.validators[s.indices[j]].ActivationEligibilityEpoch {
return s.indices[i] < s.indices[j]
}
return s.validators[s.indices[i]].ActivationEligibilityEpoch < s.validators[s.indices[j]].ActivationEligibilityEpoch
}
// AttestingBalance returns the total balance from all the attesting indices.
//
// WARNING: This method allocates a new copy of the attesting validator indices set and is
// considered to be very memory expensive. Avoid using this unless you really
// need to get attesting balance from attestations.
//
// Spec pseudocode definition:
// def get_attesting_balance(state: BeaconState, attestations: Sequence[PendingAttestation]) -> Gwei:
// """
// Return the combined effective balance of the set of unslashed validators participating in ``attestations``.
// Note: ``get_total_balance`` returns ``EFFECTIVE_BALANCE_INCREMENT`` Gwei minimum to avoid divisions by zero.
// """
// return get_total_balance(state, get_unslashed_attesting_indices(state, attestations))
func AttestingBalance(ctx context.Context, state state.ReadOnlyBeaconState, atts []*ethpb.PendingAttestation) (uint64, error) {
indices, err := UnslashedAttestingIndices(ctx, state, atts)
if err != nil {
return 0, errors.Wrap(err, "could not get attesting indices")
}
return helpers.TotalBalance(state, indices), nil
}
// ProcessRegistryUpdates rotates validators in and out of active pool.
// the amount to rotate is determined churn limit.
//
// Spec pseudocode definition:
// def process_registry_updates(state: BeaconState) -> None:
// # Process activation eligibility and ejections
// for index, validator in enumerate(state.validators):
// if is_eligible_for_activation_queue(validator):
// validator.activation_eligibility_epoch = get_current_epoch(state) + 1
//
// if is_active_validator(validator, get_current_epoch(state)) and validator.effective_balance <= EJECTION_BALANCE:
// initiate_validator_exit(state, ValidatorIndex(index))
//
// # Queue validators eligible for activation and not yet dequeued for activation
// activation_queue = sorted([
// index for index, validator in enumerate(state.validators)
// if is_eligible_for_activation(state, validator)
// # Order by the sequence of activation_eligibility_epoch setting and then index
// ], key=lambda index: (state.validators[index].activation_eligibility_epoch, index))
// # Dequeued validators for activation up to churn limit
// for index in activation_queue[:get_validator_churn_limit(state)]:
// validator = state.validators[index]
// validator.activation_epoch = compute_activation_exit_epoch(get_current_epoch(state))
func ProcessRegistryUpdates(ctx context.Context, state state.BeaconState) (state.BeaconState, error) {
currentEpoch := time.CurrentEpoch(state)
vals := state.Validators()
var err error
ejectionBal := params.BeaconConfig().EjectionBalance
activationEligibilityEpoch := time.CurrentEpoch(state) + 1
for idx, validator := range vals {
// Process the validators for activation eligibility.
if helpers.IsEligibleForActivationQueue(validator) {
validator.ActivationEligibilityEpoch = activationEligibilityEpoch
if err := state.UpdateValidatorAtIndex(types.ValidatorIndex(idx), validator); err != nil {
return nil, err
}
}
// Process the validators for ejection.
isActive := helpers.IsActiveValidator(validator, currentEpoch)
belowEjectionBalance := validator.EffectiveBalance <= ejectionBal
if isActive && belowEjectionBalance {
state, err = validators.InitiateValidatorExit(ctx, state, types.ValidatorIndex(idx))
if err != nil {
return nil, errors.Wrapf(err, "could not initiate exit for validator %d", idx)
}
}
}
// Queue validators eligible for activation and not yet dequeued for activation.
var activationQ []types.ValidatorIndex
for idx, validator := range vals {
if helpers.IsEligibleForActivation(state, validator) {
activationQ = append(activationQ, types.ValidatorIndex(idx))
}
}
sort.Sort(sortableIndices{indices: activationQ, validators: vals})
// Only activate just enough validators according to the activation churn limit.
limit := uint64(len(activationQ))
activeValidatorCount, err := helpers.ActiveValidatorCount(ctx, state, currentEpoch)
if err != nil {
return nil, errors.Wrap(err, "could not get active validator count")
}
churnLimit, err := helpers.ValidatorChurnLimit(activeValidatorCount)
if err != nil {
return nil, errors.Wrap(err, "could not get churn limit")
}
// Prevent churn limit cause index out of bound.
if churnLimit < limit {
limit = churnLimit
}
activationExitEpoch := helpers.ActivationExitEpoch(currentEpoch)
for _, index := range activationQ[:limit] {
validator, err := state.ValidatorAtIndex(index)
if err != nil {
return nil, err
}
validator.ActivationEpoch = activationExitEpoch
if err := state.UpdateValidatorAtIndex(index, validator); err != nil {
return nil, err
}
}
return state, nil
}
// ProcessSlashings processes the slashed validators during epoch processing,
//
// def process_slashings(state: BeaconState) -> None:
// epoch = get_current_epoch(state)
// total_balance = get_total_active_balance(state)
// adjusted_total_slashing_balance = min(sum(state.slashings) * PROPORTIONAL_SLASHING_MULTIPLIER, total_balance)
// for index, validator in enumerate(state.validators):
// if validator.slashed and epoch + EPOCHS_PER_SLASHINGS_VECTOR // 2 == validator.withdrawable_epoch:
// increment = EFFECTIVE_BALANCE_INCREMENT # Factored out from penalty numerator to avoid uint64 overflow
// penalty_numerator = validator.effective_balance // increment * adjusted_total_slashing_balance
// penalty = penalty_numerator // total_balance * increment
// decrease_balance(state, ValidatorIndex(index), penalty)
func ProcessSlashings(state state.BeaconState, slashingMultiplier uint64) (state.BeaconState, error) {
currentEpoch := time.CurrentEpoch(state)
totalBalance, err := helpers.TotalActiveBalance(state)
if err != nil {
return nil, errors.Wrap(err, "could not get total active balance")
}
// Compute slashed balances in the current epoch
exitLength := params.BeaconConfig().EpochsPerSlashingsVector
// Compute the sum of state slashings
slashings := state.Slashings()
totalSlashing := uint64(0)
for _, slashing := range slashings {
totalSlashing, err = math.Add64(totalSlashing, slashing)
if err != nil {
return nil, err
}
}
// a callback is used here to apply the following actions to all validators
// below equally.
increment := params.BeaconConfig().EffectiveBalanceIncrement
minSlashing := math.Min(totalSlashing*slashingMultiplier, totalBalance)
err = state.ApplyToEveryValidator(func(idx int, val *ethpb.Validator) (bool, *ethpb.Validator, error) {
correctEpoch := (currentEpoch + exitLength/2) == val.WithdrawableEpoch
if val.Slashed && correctEpoch {
penaltyNumerator := val.EffectiveBalance / increment * minSlashing
penalty := penaltyNumerator / totalBalance * increment
if err := helpers.DecreaseBalance(state, types.ValidatorIndex(idx), penalty); err != nil {
return false, val, err
}
return true, val, nil
}
return false, val, nil
})
return state, err
}
// ProcessEth1DataReset processes updates to ETH1 data votes during epoch processing.
//
// Spec pseudocode definition:
// def process_eth1_data_reset(state: BeaconState) -> None:
// next_epoch = Epoch(get_current_epoch(state) + 1)
// # Reset eth1 data votes
// if next_epoch % EPOCHS_PER_ETH1_VOTING_PERIOD == 0:
// state.eth1_data_votes = []
func ProcessEth1DataReset(state state.BeaconState) (state.BeaconState, error) {
currentEpoch := time.CurrentEpoch(state)
nextEpoch := currentEpoch + 1
// Reset ETH1 data votes.
if nextEpoch%params.BeaconConfig().EpochsPerEth1VotingPeriod == 0 {
if err := state.SetEth1DataVotes([]*ethpb.Eth1Data{}); err != nil {
return nil, err
}
}
return state, nil
}
// ProcessEffectiveBalanceUpdates processes effective balance updates during epoch processing.
//
// Spec pseudocode definition:
// def process_effective_balance_updates(state: BeaconState) -> None:
// # Update effective balances with hysteresis
// for index, validator in enumerate(state.validators):
// balance = state.balances[index]
// HYSTERESIS_INCREMENT = uint64(EFFECTIVE_BALANCE_INCREMENT // HYSTERESIS_QUOTIENT)
// DOWNWARD_THRESHOLD = HYSTERESIS_INCREMENT * HYSTERESIS_DOWNWARD_MULTIPLIER
// UPWARD_THRESHOLD = HYSTERESIS_INCREMENT * HYSTERESIS_UPWARD_MULTIPLIER
// if (
// balance + DOWNWARD_THRESHOLD < validator.effective_balance
// or validator.effective_balance + UPWARD_THRESHOLD < balance
// ):
// validator.effective_balance = min(balance - balance % EFFECTIVE_BALANCE_INCREMENT, MAX_EFFECTIVE_BALANCE)
func ProcessEffectiveBalanceUpdates(state state.BeaconState) (state.BeaconState, error) {
effBalanceInc := params.BeaconConfig().EffectiveBalanceIncrement
maxEffBalance := params.BeaconConfig().MaxEffectiveBalance
hysteresisInc := effBalanceInc / params.BeaconConfig().HysteresisQuotient
downwardThreshold := hysteresisInc * params.BeaconConfig().HysteresisDownwardMultiplier
upwardThreshold := hysteresisInc * params.BeaconConfig().HysteresisUpwardMultiplier
bals := state.Balances()
// Update effective balances with hysteresis.
validatorFunc := func(idx int, val *ethpb.Validator) (bool, *ethpb.Validator, error) {
if val == nil {
return false, nil, fmt.Errorf("validator %d is nil in state", idx)
}
if idx >= len(bals) {
return false, nil, fmt.Errorf("validator index exceeds validator length in state %d >= %d", idx, len(state.Balances()))
}
balance := bals[idx]
if balance+downwardThreshold < val.EffectiveBalance || val.EffectiveBalance+upwardThreshold < balance {
effectiveBal := maxEffBalance
if effectiveBal > balance-balance%effBalanceInc {
effectiveBal = balance - balance%effBalanceInc
}
if effectiveBal != val.EffectiveBalance {
newVal := ethpb.CopyValidator(val)
newVal.EffectiveBalance = effectiveBal
return true, newVal, nil
}
return false, val, nil
}
return false, val, nil
}
if err := state.ApplyToEveryValidator(validatorFunc); err != nil {
return nil, err
}
return state, nil
}
// ProcessSlashingsReset processes the total slashing balances updates during epoch processing.
//
// Spec pseudocode definition:
// def process_slashings_reset(state: BeaconState) -> None:
// next_epoch = Epoch(get_current_epoch(state) + 1)
// # Reset slashings
// state.slashings[next_epoch % EPOCHS_PER_SLASHINGS_VECTOR] = Gwei(0)
func ProcessSlashingsReset(state state.BeaconState) (state.BeaconState, error) {
currentEpoch := time.CurrentEpoch(state)
nextEpoch := currentEpoch + 1
// Set total slashed balances.
slashedExitLength := params.BeaconConfig().EpochsPerSlashingsVector
slashedEpoch := nextEpoch % slashedExitLength
slashings := state.Slashings()
if uint64(len(slashings)) != uint64(slashedExitLength) {
return nil, fmt.Errorf(
"state slashing length %d different than EpochsPerHistoricalVector %d",
len(slashings),
slashedExitLength,
)
}
if err := state.UpdateSlashingsAtIndex(uint64(slashedEpoch) /* index */, 0 /* value */); err != nil {
return nil, err
}
return state, nil
}
// ProcessRandaoMixesReset processes the final updates to RANDAO mix during epoch processing.
//
// Spec pseudocode definition:
// def process_randao_mixes_reset(state: BeaconState) -> None:
// current_epoch = get_current_epoch(state)
// next_epoch = Epoch(current_epoch + 1)
// # Set randao mix
// state.randao_mixes[next_epoch % EPOCHS_PER_HISTORICAL_VECTOR] = get_randao_mix(state, current_epoch)
func ProcessRandaoMixesReset(state state.BeaconState) (state.BeaconState, error) {
currentEpoch := time.CurrentEpoch(state)
nextEpoch := currentEpoch + 1
// Set RANDAO mix.
randaoMixLength := params.BeaconConfig().EpochsPerHistoricalVector
if uint64(state.RandaoMixesLength()) != uint64(randaoMixLength) {
return nil, fmt.Errorf(
"state randao length %d different than EpochsPerHistoricalVector %d",
state.RandaoMixesLength(),
randaoMixLength,
)
}
mix, err := helpers.RandaoMix(state, currentEpoch)
if err != nil {
return nil, err
}
if err := state.UpdateRandaoMixesAtIndex(uint64(nextEpoch%randaoMixLength), mix); err != nil {
return nil, err
}
return state, nil
}
// ProcessHistoricalRootsUpdate processes the updates to historical root accumulator during epoch processing.
//
// Spec pseudocode definition:
// def process_historical_roots_update(state: BeaconState) -> None:
// # Set historical root accumulator
// next_epoch = Epoch(get_current_epoch(state) + 1)
// if next_epoch % (SLOTS_PER_HISTORICAL_ROOT // SLOTS_PER_EPOCH) == 0:
// historical_batch = HistoricalBatch(block_roots=state.block_roots, state_roots=state.state_roots)
// state.historical_roots.append(hash_tree_root(historical_batch))
func ProcessHistoricalRootsUpdate(state state.BeaconState) (state.BeaconState, error) {
currentEpoch := time.CurrentEpoch(state)
nextEpoch := currentEpoch + 1
// Set historical root accumulator.
epochsPerHistoricalRoot := params.BeaconConfig().SlotsPerHistoricalRoot.DivSlot(params.BeaconConfig().SlotsPerEpoch)
if nextEpoch.Mod(uint64(epochsPerHistoricalRoot)) == 0 {
historicalBatch := &ethpb.HistoricalBatch{
BlockRoots: state.BlockRoots(),
StateRoots: state.StateRoots(),
}
batchRoot, err := historicalBatch.HashTreeRoot()
if err != nil {
return nil, errors.Wrap(err, "could not hash historical batch")
}
if err := state.AppendHistoricalRoots(batchRoot); err != nil {
return nil, err
}
}
return state, nil
}
// ProcessParticipationRecordUpdates rotates current/previous epoch attestations during epoch processing.
//
// Spec pseudocode definition:
// def process_participation_record_updates(state: BeaconState) -> None:
// # Rotate current/previous epoch attestations
// state.previous_epoch_attestations = state.current_epoch_attestations
// state.current_epoch_attestations = []
func ProcessParticipationRecordUpdates(state state.BeaconState) (state.BeaconState, error) {
if err := state.RotateAttestations(); err != nil {
return nil, err
}
return state, nil
}
// ProcessFinalUpdates processes the final updates during epoch processing.
func ProcessFinalUpdates(state state.BeaconState) (state.BeaconState, error) {
var err error
// Reset ETH1 data votes.
state, err = ProcessEth1DataReset(state)
if err != nil {
return nil, err
}
// Update effective balances with hysteresis.
state, err = ProcessEffectiveBalanceUpdates(state)
if err != nil {
return nil, err
}
// Set total slashed balances.
state, err = ProcessSlashingsReset(state)
if err != nil {
return nil, err
}
// Set RANDAO mix.
state, err = ProcessRandaoMixesReset(state)
if err != nil {
return nil, err
}
// Set historical root accumulator.
state, err = ProcessHistoricalRootsUpdate(state)
if err != nil {
return nil, err
}
// Rotate current and previous epoch attestations.
state, err = ProcessParticipationRecordUpdates(state)
if err != nil {
return nil, err
}
return state, nil
}
// UnslashedAttestingIndices returns all the attesting indices from a list of attestations,
// it sorts the indices and filters out the slashed ones.
//
// Spec pseudocode definition:
// def get_unslashed_attesting_indices(state: BeaconState,
// attestations: Sequence[PendingAttestation]) -> Set[ValidatorIndex]:
// output = set() # type: Set[ValidatorIndex]
// for a in attestations:
// output = output.union(get_attesting_indices(state, a.data, a.aggregation_bits))
// return set(filter(lambda index: not state.validators[index].slashed, output))
func UnslashedAttestingIndices(ctx context.Context, state state.ReadOnlyBeaconState, atts []*ethpb.PendingAttestation) ([]types.ValidatorIndex, error) {
var setIndices []types.ValidatorIndex
seen := make(map[uint64]bool)
for _, att := range atts {
committee, err := helpers.BeaconCommitteeFromState(ctx, state, att.Data.Slot, att.Data.CommitteeIndex)
if err != nil {
return nil, err
}
attestingIndices, err := attestation.AttestingIndices(att.AggregationBits, committee)
if err != nil {
return nil, err
}
// Create a set for attesting indices
for _, index := range attestingIndices {
if !seen[index] {
setIndices = append(setIndices, types.ValidatorIndex(index))
}
seen[index] = true
}
}
// Sort the attesting set indices by increasing order.
sort.Slice(setIndices, func(i, j int) bool { return setIndices[i] < setIndices[j] })
// Remove the slashed validator indices.
for i := 0; i < len(setIndices); i++ {
v, err := state.ValidatorAtIndexReadOnly(setIndices[i])
if err != nil {
return nil, errors.Wrap(err, "failed to look up validator")
}
if !v.IsNil() && v.Slashed() {
setIndices = append(setIndices[:i], setIndices[i+1:]...)
}
}
return setIndices, nil
}