validators

Documentation

Overview

Package validators contains libraries to shuffle validators and retrieve active validator indices from a given slot or an attestation. It also provides helper functions to locate validator based on pubic key.

Index

• func ActivatedValidatorIndices(epoch types.Epoch, validators []*ethpb.Validator) []types.ValidatorIndex
• func EjectedValidatorIndices(epoch types.Epoch, validators []*ethpb.Validator, activeValidatorCount uint64) ([]types.ValidatorIndex, error)
• func ExitedValidatorIndices(epoch types.Epoch, validators []*ethpb.Validator, activeValidatorCount uint64) ([]types.ValidatorIndex, error)
• func InitiateValidatorExit(state iface.BeaconState, idx types.ValidatorIndex) (iface.BeaconState, error)
• func SlashValidator(state iface.BeaconState, slashedIdx types.ValidatorIndex) (iface.BeaconState, error)
• func SlashedValidatorIndices(epoch types.Epoch, validators []*ethpb.Validator) []types.ValidatorIndex

Functions

func ActivatedValidatorIndices

func ActivatedValidatorIndices(epoch types.Epoch, validators []*ethpb.Validator) []types.ValidatorIndex

ActivatedValidatorIndices determines the indices activated during the given epoch.

func EjectedValidatorIndices

func EjectedValidatorIndices(epoch types.Epoch, validators []*ethpb.Validator, activeValidatorCount uint64) ([]types.ValidatorIndex, error)

EjectedValidatorIndices determines the indices ejected during the given epoch.

func ExitedValidatorIndices

func ExitedValidatorIndices(epoch types.Epoch, validators []*ethpb.Validator, activeValidatorCount uint64) ([]types.ValidatorIndex, error)

ExitedValidatorIndices determines the indices exited during the current epoch.

func InitiateValidatorExit

func InitiateValidatorExit(state iface.BeaconState, idx types.ValidatorIndex) (iface.BeaconState, error)

InitiateValidatorExit takes in validator index and updates validator with correct voluntary exit parameters.

Spec pseudocode definition:

def initiate_validator_exit(state: BeaconState, index: ValidatorIndex) -> None:
  """
  Initiate the exit of the validator with index ``index``.
  """
  # Return if validator already initiated exit
  validator = state.validators[index]
  if validator.exit_epoch != FAR_FUTURE_EPOCH:
      return

  # Compute exit queue epoch
  exit_epochs = [v.exit_epoch for v in state.validators if v.exit_epoch != FAR_FUTURE_EPOCH]
  exit_queue_epoch = max(exit_epochs + [compute_activation_exit_epoch(get_current_epoch(state))])
  exit_queue_churn = len([v for v in state.validators if v.exit_epoch == exit_queue_epoch])
  if exit_queue_churn >= get_validator_churn_limit(state):
      exit_queue_epoch += Epoch(1)

  # Set validator exit epoch and withdrawable epoch
  validator.exit_epoch = exit_queue_epoch
  validator.withdrawable_epoch = Epoch(validator.exit_epoch + MIN_VALIDATOR_WITHDRAWABILITY_DELAY)

func SlashValidator

func SlashValidator(state iface.BeaconState, slashedIdx types.ValidatorIndex) (iface.BeaconState, error)

SlashValidator slashes the malicious validator's balance and awards the whistleblower's balance.

Spec pseudocode definition:

def slash_validator(state: BeaconState,
                  slashed_index: ValidatorIndex,
                  whistleblower_index: ValidatorIndex=None) -> None:
  """
  Slash the validator with index ``slashed_index``.
  """
  epoch = get_current_epoch(state)
  initiate_validator_exit(state, slashed_index)
  validator = state.validators[slashed_index]
  validator.slashed = True
  validator.withdrawable_epoch = max(validator.withdrawable_epoch, Epoch(epoch + EPOCHS_PER_SLASHINGS_VECTOR))
  state.slashings[epoch % EPOCHS_PER_SLASHINGS_VECTOR] += validator.effective_balance
  decrease_balance(state, slashed_index, validator.effective_balance // MIN_SLASHING_PENALTY_QUOTIENT)

  # Apply proposer and whistleblower rewards
  proposer_index = get_beacon_proposer_index(state)
  if whistleblower_index is None:
      whistleblower_index = proposer_index
  whistleblower_reward = Gwei(validator.effective_balance // WHISTLEBLOWER_REWARD_QUOTIENT)
  proposer_reward = Gwei(whistleblower_reward // PROPOSER_REWARD_QUOTIENT)
  increase_balance(state, proposer_index, proposer_reward)
  increase_balance(state, whistleblower_index, Gwei(whistleblower_reward - proposer_reward))

func SlashedValidatorIndices

func SlashedValidatorIndices(epoch types.Epoch, validators []*ethpb.Validator) []types.ValidatorIndex

SlashedValidatorIndices determines the indices slashed during the given epoch.