def run_with(
_cls, inputs: Tuple[BeaconState, int], config: Optional[Eth2Config]
) -> BeaconState:
state, offset = inputs
target_slot = Slot(state.slot + offset)
return process_slots(state, target_slot, config)
def on_attestation(self,
attestation: Attestation,
validate_signature: bool = True) -> None:
target = attestation.data.target
current_epoch = compute_epoch_at_slot(self.get_current_slot(),
self._config.SLOTS_PER_EPOCH)
previous_epoch = (current_epoch -
1 if current_epoch > self._config.GENESIS_EPOCH else
self._config.GENESIS_EPOCH)
if target.epoch not in (current_epoch, previous_epoch):
raise ValidationError(
"Attestations must be from the current or previous epoch")
if target.root not in self._context.blocks:
raise ValidationError(
"Attestation targets a block we have not seen")
base_state = self._context.block_states[target.root]
time_of_target_epoch = (
base_state.genesis_time + compute_start_slot_at_epoch(
target.epoch, self._config.SLOTS_PER_EPOCH) *
self._config.SECONDS_PER_SLOT)
if self._context.time < time_of_target_epoch:
raise ValidationError("Attestation cannot be for a future epoch")
beacon_block_root = attestation.data.beacon_block_root
if beacon_block_root not in self._context.blocks:
raise ValidationError("Attestations must be for a known block")
if self._context.blocks[beacon_block_root].slot > attestation.data.slot:
raise ValidationError(
"Attestations must not be for a block in the future")
if target not in self._context.checkpoint_states:
base_state = process_slots(
base_state,
compute_start_slot_at_epoch(target.epoch,
self._config.SLOTS_PER_EPOCH),
self._config,
)
self._context.checkpoint_states[target] = base_state
target_state = self._context.checkpoint_states[target]
if (self._context.time <
(attestation.data.slot + 1) * self._config.SECONDS_PER_SLOT):
raise ValidationError(
"Attestations can only affect the fork choice of future slots")
# TODO: has this validation already been performed?
indexed_attestation = get_indexed_attestation(
target_state, attestation, CommitteeConfig(self._config))
validate_indexed_attestation(
target_state,
indexed_attestation,
self._config.MAX_VALIDATORS_PER_COMMITTEE,
self._config.SLOTS_PER_EPOCH,
validate_signature=validate_signature,
)
for i in indexed_attestation.attesting_indices:
if (i not in self._context.latest_messages
or target.epoch > self._context.latest_messages[i].epoch):
self._context.latest_messages[i] = LatestMessage(
epoch=target.epoch,
root=attestation.data.beacon_block_root)