nimbus-eth2/beacon_chain/statediff.nim

196 lines
7.4 KiB
Nim

# beacon_chain
# Copyright (c) 2020-2021 Status Research & Development GmbH
# Licensed and distributed under either of
# * MIT license (license terms in the root directory or at https://opensource.org/licenses/MIT).
# * Apache v2 license (license terms in the root directory or at https://www.apache.org/licenses/LICENSE-2.0).
# at your option. This file may not be copied, modified, or distributed except according to those terms.
{.push raises: [Defect].}
import
stew/assign2,
./ssz/types,
./spec/[datatypes, digest, helpers]
func diffModIncEpoch[T, U](hl: HashArray[U, T], startSlot: uint64):
array[SLOTS_PER_EPOCH, T] =
static: doAssert U.uint64 mod SLOTS_PER_EPOCH == 0
doAssert startSlot mod SLOTS_PER_EPOCH == 0
for i in startSlot ..< startSlot + SLOTS_PER_EPOCH:
result[i mod SLOTS_PER_EPOCH] = hl[i mod U.uint64]
func applyModIncrement[T, U](
ha: var HashArray[U, T], hl: array[SLOTS_PER_EPOCH, T], slot: uint64) =
var indexSlot = slot
for item in hl:
ha[indexSlot mod U.uint64] = item
indexSlot += 1
func applyValidatorIdentities(
validators: var HashList[Validator, Limit VALIDATOR_REGISTRY_LIMIT],
hl: auto) =
for item in hl:
validators.add Validator(
pubkey: item.pubkey,
withdrawal_credentials: item.withdrawal_credentials)
func setValidatorStatuses(
validators: var HashList[Validator, Limit VALIDATOR_REGISTRY_LIMIT],
hl: List[ValidatorStatus, Limit VALIDATOR_REGISTRY_LIMIT]) =
doAssert validators.len == hl.len
for i in 0 ..< hl.len:
validators[i].effective_balance = hl[i].effective_balance
validators[i].slashed = hl[i].slashed
validators[i].activation_eligibility_epoch =
hl[i].activation_eligibility_epoch
validators[i].activation_epoch = hl[i].activation_epoch
validators[i].exit_epoch = hl[i].exit_epoch
validators[i].withdrawable_epoch = hl[i].withdrawable_epoch
func replaceOrAddEncodeEth1Votes[T, U](votes0, votes1: HashList[T, U]):
(bool, List[T, U]) =
let
num_votes0 = votes0.len
lower_bound =
if votes1.len < num_votes0 or
(num_votes0 > 0 and votes0[num_votes0 - 1] != votes1[num_votes0 - 1]):
# EPOCHS_PER_ETH1_VOTING_PERIOD epochs have passed, and
# eth1_data_votes has been reset/cleared. Because their
# deposit_index counts increase monotonically, it works
# to use only the last element for comparison.
0
else:
num_votes0
result[0] = lower_bound == 0
for i in lower_bound ..< votes1.len:
result[1].add votes1[i]
func replaceOrAddDecodeEth1Votes[T, U](
votes0: var HashList[T, U], eth1_data_votes_replaced: bool,
votes1: List[T, U]) =
if eth1_data_votes_replaced:
votes0 = HashList[T, U]()
for item in votes1:
votes0.add item
func getMutableValidatorStatus(validator: Validator): ValidatorStatus =
ValidatorStatus(
effective_balance: validator.effective_balance,
slashed: validator.slashed,
activation_eligibility_epoch: validator.activation_eligibility_epoch,
activation_epoch: validator.activation_epoch,
exit_epoch: validator.exit_epoch,
withdrawable_epoch: validator.withdrawable_epoch)
func getMutableValidatorStatuses(state: BeaconState):
List[ValidatorStatus, Limit VALIDATOR_REGISTRY_LIMIT] =
# use mapIt + .init(foo)?
for validator in state.validators:
result.add getMutableValidatorStatus(validator)
func diffStates*(state0, state1: BeaconState): BeaconStateDiff =
doAssert state1.slot > state0.slot
doAssert state0.slot.isEpoch
doAssert state1.slot == state0.slot + SLOTS_PER_EPOCH
# TODO not here, but in chainDag, an isancestorof check
doAssert state0.genesis_time == state1.genesis_time
doAssert state0.genesis_validators_root == state1.genesis_validators_root
doAssert state0.fork == state1.fork
doAssert state1.historical_roots.len - state0.historical_roots.len in [0, 1]
let
historical_root_added =
state0.historical_roots.len != state1.historical_roots.len
(eth1_data_votes_replaced, eth1_data_votes) =
replaceOrAddEncodeEth1Votes(state0.eth1_data_votes, state1.eth1_data_votes)
BeaconStateDiff(
slot: state1.slot,
latest_block_header: state1.latest_block_header,
block_roots: diffModIncEpoch(state1.block_roots, state0.slot.uint64),
state_roots: diffModIncEpoch(state1.state_roots, state0.slot.uint64),
historical_root_added: historical_root_added,
historical_root:
if historical_root_added:
state1.historical_roots[state0.historical_roots.len]
else:
default(Eth2Digest),
eth1_data: state1.eth1_data,
eth1_data_votes_replaced: eth1_data_votes_replaced,
eth1_data_votes: eth1_data_votes,
eth1_deposit_index: state1.eth1_deposit_index,
validatorStatuses: getMutableValidatorStatuses(state1),
balances: state1.balances.data,
# RANDAO mixes gets updated every block, in place
randao_mix: state1.randao_mixes[state0.slot.compute_epoch_at_slot.uint64 mod
EPOCHS_PER_HISTORICAL_VECTOR.uint64],
slashing: state1.slashings[state0.slot.compute_epoch_at_slot.uint64 mod
EPOCHS_PER_HISTORICAL_VECTOR.uint64],
previous_epoch_attestations: state1.previous_epoch_attestations.data,
current_epoch_attestations: state1.current_epoch_attestations.data,
justification_bits: state1.justification_bits,
previous_justified_checkpoint: state1.previous_justified_checkpoint,
current_justified_checkpoint: state1.current_justified_checkpoint,
finalized_checkpoint: state1.finalized_checkpoint
)
func applyDiff*(
state: var BeaconState,
immutableValidators: openArray[ImmutableValidatorData],
stateDiff: BeaconStateDiff) =
template assign[T, U](tgt: var HashList[T, U], src: List[T, U]) =
tgt.clear()
assign(tgt.data, src)
tgt.growHashes()
# Carry over unchanged genesis_time, genesis_validators_root, and fork.
assign(state.latest_block_header, stateDiff.latest_block_header)
applyModIncrement(state.block_roots, stateDiff.block_roots, state.slot.uint64)
applyModIncrement(state.state_roots, stateDiff.state_roots, state.slot.uint64)
if stateDiff.historical_root_added:
state.historical_roots.add stateDiff.historical_root
assign(state.eth1_data, stateDiff.eth1_data)
replaceOrAddDecodeEth1Votes(
state.eth1_data_votes, stateDiff.eth1_data_votes_replaced,
stateDiff.eth1_data_votes)
assign(state.eth1_deposit_index, stateDiff.eth1_deposit_index)
applyValidatorIdentities(state.validators, immutableValidators)
setValidatorStatuses(state.validators, stateDiff.validator_statuses)
assign(state.balances, stateDiff.balances)
# RANDAO mixes gets updated every block, in place, so ensure there's always
# >=1 value from it
let epochIndex =
state.slot.epoch.uint64 mod EPOCHS_PER_HISTORICAL_VECTOR.uint64
assign(state.randao_mixes[epochIndex], stateDiff.randao_mix)
assign(state.slashings[epochIndex], stateDiff.slashing)
assign(
state.previous_epoch_attestations, stateDiff.previous_epoch_attestations)
assign(
state.current_epoch_attestations, stateDiff.current_epoch_attestations)
state.justification_bits = stateDiff.justification_bits
assign(
state.previous_justified_checkpoint, stateDiff.previous_justified_checkpoint)
assign(
state.current_justified_checkpoint, stateDiff.current_justified_checkpoint)
assign(state.finalized_checkpoint, stateDiff.finalized_checkpoint)
# Don't update slot until the end, because various other updates depend on it
state.slot = stateDiff.slot