def _is_threshold_met_against_committee(
state: BeaconState,
attesting_indices: Set[ValidatorIndex],
committee: Set[ValidatorIndex],
) -> bool:
total_attesting_balance = get_total_balance(state, attesting_indices)
total_committee_balance = get_total_balance(state, committee)
return _bft_threshold_met(total_attesting_balance, total_committee_balance)
def get_crosslink_deltas(
state: BeaconState,
config: Eth2Config) -> Tuple[Sequence[Gwei], Sequence[Gwei]]:
rewards = tuple(0 for _ in range(len(state.validators)))
penalties = tuple(0 for _ in range(len(state.validators)))
epoch = state.previous_epoch(config.SLOTS_PER_EPOCH, config.GENESIS_EPOCH)
active_validators_indices = get_active_validator_indices(
state.validators, epoch)
epoch_committee_count = get_committee_count(
len(active_validators_indices),
config.SHARD_COUNT,
config.SLOTS_PER_EPOCH,
config.TARGET_COMMITTEE_SIZE,
)
epoch_start_shard = get_start_shard(
state,
epoch,
CommitteeConfig(config),
)
for shard_offset in range(epoch_committee_count):
shard = Shard((epoch_start_shard + shard_offset) % config.SHARD_COUNT)
crosslink_committee = set(
get_crosslink_committee(
state,
epoch,
shard,
CommitteeConfig(config),
))
_, attesting_indices = get_winning_crosslink_and_attesting_indices(
state=state,
epoch=epoch,
shard=shard,
config=config,
)
total_attesting_balance = get_total_balance(
state,
attesting_indices,
)
total_committee_balance = get_total_balance(
state,
crosslink_committee,
)
for index in crosslink_committee:
base_reward = get_base_reward(state, index, config)
if index in attesting_indices:
rewards = update_tuple_item_with_fn(
rewards, index, lambda balance, delta: balance + delta,
base_reward * total_attesting_balance //
total_committee_balance)
else:
penalties = update_tuple_item_with_fn(
penalties,
index,
lambda balance, delta: balance + delta,
base_reward,
)
return tuple(Gwei(reward) for reward in rewards), tuple(
Gwei(penalty) for penalty in penalties)
def _is_epoch_justifiable(state: BeaconState,
attestations: Sequence[PendingAttestationRecord],
epoch: Epoch, config: Eth2Config) -> bool:
"""
Determine if epoch boundary attesting balance is greater than 2/3 of total_balance
for the given ``epoch``.
"""
active_validator_indices = get_active_validator_indices(
state.validator_registry,
epoch,
)
if not active_validator_indices:
return False
total_balance = get_total_balance(
state.validator_balances,
active_validator_indices,
config.MAX_DEPOSIT_AMOUNT,
)
attesting_balance = get_epoch_boundary_attesting_balance(
state, attestations, epoch, config)
return 3 * attesting_balance >= 2 * total_balance
def _process_rewards_and_penalties_for_crosslinks(
state: BeaconState, config: Eth2Config,
effective_balances: Dict[ValidatorIndex,
Gwei], base_rewards: Dict[ValidatorIndex, Gwei]
) -> Tuple[Dict[ValidatorIndex, Gwei], Dict[ValidatorIndex,
Gwei]]: # noqa: E501
previous_epoch_start_slot = get_epoch_start_slot(
state.previous_epoch(config.SLOTS_PER_EPOCH),
config.SLOTS_PER_EPOCH,
)
current_epoch_start_slot = get_epoch_start_slot(
state.current_epoch(config.SLOTS_PER_EPOCH),
config.SLOTS_PER_EPOCH,
)
rewards_received = {
ValidatorIndex(index): Gwei(0)
for index in range(len(state.validator_registry))
}
penalties_received = rewards_received.copy()
for slot in range(previous_epoch_start_slot, current_epoch_start_slot):
crosslink_committees_at_slot = get_crosslink_committees_at_slot(
state,
slot,
CommitteeConfig(config),
)
for crosslink_committee, shard in crosslink_committees_at_slot:
winning_root, attesting_validator_indices = get_winning_root_and_participants(
state=state,
shard=shard,
effective_balances=effective_balances,
committee_config=CommitteeConfig(config),
)
total_attesting_balance = get_total_balance(
state.validator_balances,
attesting_validator_indices,
config.MAX_DEPOSIT_AMOUNT,
)
total_balance = get_total_balance_from_effective_balances(
effective_balances,
crosslink_committee,
)
for index in attesting_validator_indices:
rewards_received = _update_rewards_or_penalies(
index,
base_rewards[index] * total_attesting_balance //
total_balance,
rewards_received,
)
for index in set(crosslink_committee).difference(
attesting_validator_indices):
penalties_received = _update_rewards_or_penalies(
index,
base_rewards[index],
penalties_received,
)
return (rewards_received, penalties_received)
def _current_previous_epochs_justifiable(
state: BeaconState, current_epoch: Epoch, previous_epoch: Epoch,
config: BeaconConfig) -> Tuple[bool, bool]:
"""
Determine if epoch boundary attesting balance is greater than 2/3 of current_total_balance
for current and previous epochs.
"""
current_epoch_active_validator_indices = get_active_validator_indices(
state.validator_registry,
current_epoch,
)
previous_epoch_active_validator_indices = get_active_validator_indices(
state.validator_registry,
previous_epoch,
)
current_total_balance = get_total_balance(
state.validator_balances,
current_epoch_active_validator_indices,
config.MAX_DEPOSIT_AMOUNT,
)
previous_total_balance = get_total_balance(
state.validator_balances,
previous_epoch_active_validator_indices,
config.MAX_DEPOSIT_AMOUNT,
)
(previous_epoch_boundary_attesting_balance,
current_epoch_boundary_attesting_balance
) = get_epoch_boundary_attesting_balances(current_epoch, previous_epoch,
state, config)
previous_epoch_justifiable = (3 * previous_epoch_boundary_attesting_balance
>= 2 * previous_total_balance)
current_epoch_justifiable = (3 * current_epoch_boundary_attesting_balance
>= 2 * current_total_balance)
return current_epoch_justifiable, previous_epoch_justifiable
def get_attestation_deltas(
state: BeaconState,
config: Eth2Config) -> Tuple[Sequence[Gwei], Sequence[Gwei]]:
rewards = tuple(0 for _ in range(len(state.validators)))
penalties = tuple(0 for _ in range(len(state.validators)))
previous_epoch = state.previous_epoch(config.SLOTS_PER_EPOCH)
total_balance = get_total_active_balance(state, config)
eligible_validator_indices = tuple(
ValidatorIndex(index) for index, v in enumerate(state.validators)
if v.is_active(previous_epoch) or (
v.slashed and previous_epoch + 1 < v.withdrawable_epoch))
matching_source_attestations = get_matching_source_attestations(
state, previous_epoch, config)
matching_target_attestations = get_matching_target_attestations(
state, previous_epoch, config)
matching_head_attestations = get_matching_head_attestations(
state, previous_epoch, config)
increment = config.EFFECTIVE_BALANCE_INCREMENT
total_balance_in_increment = total_balance // increment
for attestations in (
matching_source_attestations,
matching_target_attestations,
matching_head_attestations,
):
unslashed_attesting_indices = get_unslashed_attesting_indices(
state, attestations, config)
attesting_balance = get_total_balance(state,
unslashed_attesting_indices,
config)
attesting_balance_in_increment = attesting_balance // increment
for index in eligible_validator_indices:
if index in unslashed_attesting_indices:
if is_in_inactivity_leak(state, config):
reward = get_base_reward(state, index, config)
else:
reward = Gwei((get_base_reward(state, index, config) *
attesting_balance_in_increment) //
total_balance_in_increment)
rewards = update_tuple_item_with_fn(
rewards, index, lambda balance, delta: balance + delta,
reward)
else:
penalties = update_tuple_item_with_fn(
penalties,
index,
lambda balance, delta: balance + delta,
get_base_reward(state, index, config),
)
for index in get_unslashed_attesting_indices(state,
matching_source_attestations,
config):
attestation = min(
(a for a in matching_source_attestations if index in
get_attesting_indices(state, a.data, a.aggregation_bits, config)),
key=lambda a: a.inclusion_delay,
)
proposer_reward = get_proposer_reward(state, index, config)
rewards = update_tuple_item_with_fn(
rewards,
attestation.proposer_index,
lambda balance, delta: balance + delta,
proposer_reward,
)
base_reward = get_base_reward(state, index, config)
max_attester_reward = base_reward - proposer_reward
rewards = update_tuple_item_with_fn(
rewards,
index,
lambda balance, delta: balance + delta,
(max_attester_reward // attestation.inclusion_delay),
)
if is_in_inactivity_leak(state, config):
matching_target_attesting_indices = get_unslashed_attesting_indices(
state, matching_target_attestations, config)
for index in eligible_validator_indices:
base_reward = get_base_reward(state, index, config)
penalties = update_tuple_item_with_fn(
penalties,
index,
lambda balance, delta: balance + delta,
BASE_REWARDS_PER_EPOCH * base_reward -
get_proposer_reward(state, index, config),
)
if index not in matching_target_attesting_indices:
effective_balance = state.validators[index].effective_balance
penalties = update_tuple_item_with_fn(
penalties,
index,
lambda balance, delta: balance + delta,
effective_balance *
get_finality_delay(state, config.SLOTS_PER_EPOCH) //
config.INACTIVITY_PENALTY_QUOTIENT,
)
return (
tuple(Gwei(reward) for reward in rewards),
tuple(Gwei(penalty) for penalty in penalties),
)
def get_attestation_deltas(state: BeaconState,
config: Eth2Config) -> Tuple[Sequence[Gwei], Sequence[Gwei]]:
committee_config = CommitteeConfig(config)
rewards = tuple(
0 for _ in range(len(state.validators))
)
penalties = tuple(
0 for _ in range(len(state.validators))
)
previous_epoch = state.previous_epoch(config.SLOTS_PER_EPOCH, config.GENESIS_EPOCH)
total_balance = get_total_active_balance(state, config)
eligible_validator_indices = tuple(
ValidatorIndex(index) for index, v in enumerate(state.validators)
if v.is_active(previous_epoch) or (
v.slashed and previous_epoch + 1 < v.withdrawable_epoch
)
)
matching_source_attestations = get_matching_source_attestations(
state,
previous_epoch,
config,
)
matching_target_attestations = get_matching_target_attestations(
state,
previous_epoch,
config,
)
matching_head_attestations = get_matching_head_attestations(
state,
previous_epoch,
config,
)
for attestations in (
matching_source_attestations,
matching_target_attestations,
matching_head_attestations
):
unslashed_attesting_indices = get_unslashed_attesting_indices(
state,
attestations,
committee_config,
)
attesting_balance = get_total_balance(state, unslashed_attesting_indices)
for index in eligible_validator_indices:
if index in unslashed_attesting_indices:
rewards = update_tuple_item_with_fn(
rewards,
index,
lambda balance, delta: balance + delta,
get_base_reward(
state,
index,
config,
) * attesting_balance // total_balance,
)
else:
penalties = update_tuple_item_with_fn(
penalties,
index,
lambda balance, delta: balance + delta,
get_base_reward(
state,
index,
config,
),
)
for index in get_unslashed_attesting_indices(
state,
matching_source_attestations,
committee_config,
):
attestation = min(
(
a for a in matching_source_attestations
if index in get_attesting_indices(
state,
a.data,
a.aggregation_bitfield,
committee_config,
)
),
key=lambda a: a.inclusion_delay,
)
base_reward = get_base_reward(state, index, config)
proposer_reward = base_reward // config.PROPOSER_REWARD_QUOTIENT
rewards = update_tuple_item_with_fn(
rewards,
attestation.proposer_index,
lambda balance, delta: balance + delta,
proposer_reward,
)
max_attester_reward = base_reward - proposer_reward
rewards = update_tuple_item_with_fn(
rewards,
index,
lambda balance, delta: balance + delta,
(
max_attester_reward *
config.MIN_ATTESTATION_INCLUSION_DELAY //
attestation.inclusion_delay
)
)
finality_delay = previous_epoch - state.finalized_epoch
if finality_delay > config.MIN_EPOCHS_TO_INACTIVITY_PENALTY:
matching_target_attesting_indices = get_unslashed_attesting_indices(
state,
matching_target_attestations,
committee_config,
)
for index in eligible_validator_indices:
penalties = update_tuple_item_with_fn(
penalties,
index,
lambda balance, delta: balance + delta,
BASE_REWARDS_PER_EPOCH * get_base_reward(
state,
index,
config,
),
)
if index not in matching_target_attesting_indices:
effective_balance = state.validators[index].effective_balance
penalties = update_tuple_item_with_fn(
penalties,
index,
lambda balance, delta: balance + delta,
effective_balance * finality_delay // config.INACTIVITY_PENALTY_QUOTIENT,
)
return tuple(
Gwei(reward) for reward in rewards
), tuple(
Gwei(penalty) for penalty in penalties
)
def test_get_winning_root(random, monkeypatch, target_committee_size,
block_root_1_participants, block_root_2_participants,
config, committee_config, n_validators_state,
sample_attestation_data_params,
sample_attestation_params):
shard = 1
committee = tuple([i for i in range(target_committee_size)])
from eth2.beacon import committee_helpers
def mock_get_crosslink_committees_at_slot(state,
slot,
committee_config,
registry_change=False):
return ((
committee,
shard,
), )
monkeypatch.setattr(committee_helpers, 'get_crosslink_committees_at_slot',
mock_get_crosslink_committees_at_slot)
competing_block_roots = [
hash_eth2(bytearray(random.getrandbits(8) for _ in range(10))),
hash_eth2(bytearray(random.getrandbits(8) for _ in range(10)))
]
# Generate bitfield of each participants set
root_1_participants_bitfield = get_aggregation_bitfield(
block_root_1_participants,
target_committee_size,
)
root_2_participants_bitfield = get_aggregation_bitfield(
block_root_2_participants,
target_committee_size,
)
# `attestions` contains attestation to different block root by different set of participants
attestations = (
# Attestation to `crosslink_data_root_1` by `attestation_participants_1`
Attestation(**sample_attestation_params).copy(
aggregation_bitfield=root_1_participants_bitfield,
data=AttestationData(**sample_attestation_data_params).copy(
shard=shard,
crosslink_data_root=competing_block_roots[0],
),
),
# Attestation to `crosslink_data_root_2` by `attestation_participants_2`
Attestation(**sample_attestation_params).copy(
aggregation_bitfield=root_2_participants_bitfield,
data=AttestationData(**sample_attestation_data_params).copy(
shard=shard,
crosslink_data_root=competing_block_roots[1],
),
),
)
try:
winning_root, attesting_balance = get_winning_root(
state=n_validators_state,
shard=shard,
attestations=attestations,
max_deposit_amount=config.MAX_DEPOSIT_AMOUNT,
committee_config=committee_config,
)
attesting_validators_indices = get_attester_indices_from_attesttion(
state=n_validators_state,
attestations=(a for a in attestations if a.data.shard == shard
and a.data.crosslink_data_root == winning_root),
committee_config=committee_config,
)
total_attesting_balance = get_total_balance(
n_validators_state.validator_balances,
attesting_validators_indices,
config.MAX_DEPOSIT_AMOUNT,
)
assert attesting_balance == total_attesting_balance
except NoWinningRootError:
assert len(block_root_1_participants) == 0 and len(
block_root_2_participants) == 0
else:
if len(block_root_1_participants) == len(block_root_2_participants):
if competing_block_roots[0] < competing_block_roots[1]:
assert winning_root == competing_block_roots[0]
else:
assert winning_root == competing_block_roots[1]
elif len(block_root_1_participants) < len(block_root_2_participants):
assert winning_root == competing_block_roots[1]
else:
assert winning_root == competing_block_roots[0]
def update_validator_registry(state: BeaconState,
config: BeaconConfig) -> BeaconState:
"""
Update validator registry.
"""
current_epoch = state.current_epoch(config.SLOTS_PER_EPOCH)
# The active validators
active_validator_indices = get_active_validator_indices(
state.validator_registry, current_epoch)
# The total effective balance of active validators
total_balance = get_total_balance(
state.validator_balances,
active_validator_indices,
config.MAX_DEPOSIT_AMOUNT,
)
# The maximum balance churn in Gwei (for deposits and exits separately)
max_balance_churn = max(
config.MAX_DEPOSIT_AMOUNT,
total_balance // (2 * config.MAX_BALANCE_CHURN_QUOTIENT))
# Activate validators within the allowable balance churn
# linter didn't like a bare lambda
state = _churn_validators(
state=state,
config=config,
check_should_churn_fn=lambda state, index: _is_ready_to_activate(
state,
index,
max_deposit_amount=config.MAX_DEPOSIT_AMOUNT,
),
churn_fn=lambda state, index: activate_validator(
state,
index,
is_genesis=False,
genesis_epoch=config.GENESIS_EPOCH,
slots_per_epoch=config.SLOTS_PER_EPOCH,
activation_exit_delay=config.ACTIVATION_EXIT_DELAY,
),
max_balance_churn=max_balance_churn,
)
# Exit validators within the allowable balance churn
# linter didn't like a bare lambda
state = _churn_validators(
state=state,
config=config,
check_should_churn_fn=lambda state, index: _is_ready_to_exit(
state, index),
churn_fn=lambda state, index: exit_validator(
state,
index,
slots_per_epoch=config.SLOTS_PER_EPOCH,
activation_exit_delay=config.ACTIVATION_EXIT_DELAY,
),
max_balance_churn=max_balance_churn,
)
state = state.copy(validator_registry_update_epoch=current_epoch, )
return state
def process_rewards_and_penalties(state: BeaconState,
config: BeaconConfig) -> BeaconState:
# Compute previous epoch active validator indices and the total balance they account for
# for later use.
previous_epoch_active_validator_indices = set(
get_active_validator_indices(
state.validator_registry,
state.previous_epoch(config.SLOTS_PER_EPOCH,
config.GENESIS_EPOCH)))
previous_total_balance: Gwei = get_total_balance(
state.validator_balances,
tuple(previous_epoch_active_validator_indices),
config.MAX_DEPOSIT_AMOUNT,
)
# Compute previous epoch attester indices and the total balance they account for
# for later use.
previous_epoch_attestations = get_previous_epoch_attestations(
state,
config.SLOTS_PER_EPOCH,
config.GENESIS_EPOCH,
)
previous_epoch_attester_indices = get_attester_indices_from_attesttion(
state=state,
attestations=previous_epoch_attestations,
committee_config=CommitteeConfig(config),
)
# Compute inclusion slot/distance of previous attestations for later use.
inclusion_infos = get_inclusion_infos(
state=state,
attestations=previous_epoch_attestations,
committee_config=CommitteeConfig(config),
)
# Compute effective balance of each previous epoch active validator for later use
effective_balances = {
index: get_effective_balance(
state.validator_balances,
index,
config.MAX_DEPOSIT_AMOUNT,
)
for index in previous_epoch_active_validator_indices
}
# Compute base reward of each previous epoch active validator for later use
_base_reward_quotient = (integer_squareroot(previous_total_balance) //
config.BASE_REWARD_QUOTIENT)
base_rewards = {
index: get_base_reward(
state=state,
index=index,
base_reward_quotient=_base_reward_quotient,
max_deposit_amount=config.MAX_DEPOSIT_AMOUNT,
)
for index in previous_epoch_active_validator_indices
}
# Initialize the reward (validator) received map
rewards_received = {
index: SignedGwei(0)
for index in previous_epoch_active_validator_indices
}
# 1. Process rewards and penalties for justification and finalization
rewards_received = pipe(
rewards_received,
_process_rewards_and_penalties_for_finality(
state,
config,
previous_epoch_active_validator_indices,
previous_total_balance,
previous_epoch_attestations,
previous_epoch_attester_indices,
inclusion_infos,
effective_balances,
base_rewards,
),
_process_rewards_and_penalties_for_attestation_inclusion(
state,
config,
previous_epoch_attester_indices,
inclusion_infos,
base_rewards,
),
_process_rewards_and_penalties_for_crosslinks(
state,
config,
previous_epoch_attestations,
effective_balances,
base_rewards,
))
# Apply the overall rewards/penalties
for index in previous_epoch_active_validator_indices:
state = state.update_validator_balance(
index,
# Prevent validator balance under flow
max(state.validator_balances[index] + rewards_received[index], 0),
)
return state
def process_crosslinks(state: BeaconState,
config: BeaconConfig) -> BeaconState:
"""
Implement 'per-epoch-processing.crosslinks' portion of Phase 0 spec:
https://github.com/ethereum/eth2.0-specs/blob/master/specs/core/0_beacon-chain.md#crosslinks
For each shard from the past two epochs, find the shard block
root that has been attested to by the most stake.
If enough(>= 2/3 total stake) attesting stake, update the crosslink record of that shard.
Return resulting ``state``
"""
latest_crosslinks = state.latest_crosslinks
previous_epoch_attestations = get_previous_epoch_attestations(
state,
config.SLOTS_PER_EPOCH,
config.GENESIS_EPOCH,
)
current_epoch_attestations = get_current_epoch_attestations(
state, config.SLOTS_PER_EPOCH)
previous_epoch_start_slot = get_epoch_start_slot(
state.previous_epoch(config.SLOTS_PER_EPOCH, config.GENESIS_EPOCH),
config.SLOTS_PER_EPOCH,
)
next_epoch_start_slot = get_epoch_start_slot(
state.next_epoch(config.SLOTS_PER_EPOCH),
config.SLOTS_PER_EPOCH,
)
for slot in range(previous_epoch_start_slot, next_epoch_start_slot):
crosslink_committees_at_slot = get_crosslink_committees_at_slot(
state,
slot,
CommitteeConfig(config),
)
for crosslink_committee, shard in crosslink_committees_at_slot:
try:
winning_root, total_attesting_balance = get_winning_root(
state=state,
shard=shard,
# Use `_filter_attestations_by_shard` to filter out attestations
# not attesting to this shard so we don't need to going over
# irrelevent attestations over and over again.
attestations=_filter_attestations_by_shard(
previous_epoch_attestations +
current_epoch_attestations,
shard,
),
max_deposit_amount=config.MAX_DEPOSIT_AMOUNT,
committee_config=CommitteeConfig(config),
)
except NoWinningRootError:
# No winning shard block root found for this shard.
pass
else:
total_balance = get_total_balance(
state.validator_balances,
crosslink_committee,
config.MAX_DEPOSIT_AMOUNT,
)
if 3 * total_attesting_balance >= 2 * total_balance:
latest_crosslinks = update_tuple_item(
latest_crosslinks,
shard,
CrosslinkRecord(
epoch=state.current_epoch(config.SLOTS_PER_EPOCH),
crosslink_data_root=winning_root,
),
)
else:
# Don't update the crosslink of this shard
pass
state = state.copy(latest_crosslinks=latest_crosslinks, )
return state
def process_rewards_and_penalties(state: BeaconState,
config: Eth2Config) -> BeaconState:
# Compute previous epoch active validator indices and the total balance they account for
# for later use.
previous_epoch_active_validator_indices = set(
get_active_validator_indices(
state.validator_registry,
state.previous_epoch(config.SLOTS_PER_EPOCH)))
previous_total_balance: Gwei = get_total_balance(
state.validator_balances,
tuple(previous_epoch_active_validator_indices),
config.MAX_DEPOSIT_AMOUNT,
)
# Compute previous epoch attester indices and the total balance they account for
# for later use.
previous_epoch_attestations = state.previous_epoch_attestations
previous_epoch_attester_indices = get_attester_indices_from_attestations(
state=state,
attestations=previous_epoch_attestations,
committee_config=CommitteeConfig(config),
)
# Compute inclusion slot/distance of previous attestations for later use.
inclusion_infos = get_inclusion_infos(
state=state,
attestations=previous_epoch_attestations,
committee_config=CommitteeConfig(config),
)
# Compute effective balance of each previous epoch active validator for later use
effective_balances = {
ValidatorIndex(index): get_effective_balance(
state.validator_balances,
ValidatorIndex(index),
config.MAX_DEPOSIT_AMOUNT,
)
for index in range(len(state.validator_registry))
}
# Compute base reward of each previous epoch active validator for later use
base_rewards = {
ValidatorIndex(index): get_base_reward(
state=state,
index=ValidatorIndex(index),
base_reward_quotient=config.BASE_REWARD_QUOTIENT,
previous_total_balance=previous_total_balance,
max_deposit_amount=config.MAX_DEPOSIT_AMOUNT,
)
for index in range(len(state.validator_registry))
}
# 1. Process rewards and penalties for justification and finalization
finality_rewards, finality_penalties = _process_rewards_and_penalties_for_finality(
state,
config,
previous_epoch_active_validator_indices,
previous_total_balance,
previous_epoch_attestations,
previous_epoch_attester_indices,
inclusion_infos,
effective_balances,
base_rewards,
)
# 2. Process rewards and penalties for crosslinks
crosslinks_rewards, crosslinks_penalties = _process_rewards_and_penalties_for_crosslinks(
state,
config,
effective_balances,
base_rewards,
)
# Apply the overall rewards/penalties
for index in range(len(state.validator_registry)):
state = state.update_validator_balance(
ValidatorIndex(index),
# Prevent validator balance under flow
max(
(state.validator_balances[index] + finality_rewards[index] +
crosslinks_rewards[index] - finality_penalties[index] -
crosslinks_penalties[index]),
0,
),
)
return state
def process_crosslinks(state: BeaconState, config: Eth2Config) -> BeaconState:
"""
Implement 'per-epoch-processing.crosslinks' portion of Phase 0 spec:
https://github.com/ethereum/eth2.0-specs/blob/master/specs/core/0_beacon-chain.md#crosslinks
For each shard from the past two epochs, find the shard block
root that has been attested to by the most stake.
If enough(>= 2/3 total stake) attesting stake, update the crosslink record of that shard.
Return resulting ``state``
"""
latest_crosslinks = state.latest_crosslinks
effective_balances = {
ValidatorIndex(index): get_effective_balance(
state.validator_balances,
ValidatorIndex(index),
config.MAX_DEPOSIT_AMOUNT,
)
for index in range(len(state.validator_registry))
}
previous_epoch_start_slot = get_epoch_start_slot(
state.previous_epoch(config.SLOTS_PER_EPOCH),
config.SLOTS_PER_EPOCH,
)
next_epoch_start_slot = get_epoch_start_slot(
state.next_epoch(config.SLOTS_PER_EPOCH),
config.SLOTS_PER_EPOCH,
)
for slot in range(previous_epoch_start_slot, next_epoch_start_slot):
crosslink_committees_at_slot = get_crosslink_committees_at_slot(
state,
slot,
CommitteeConfig(config),
)
for crosslink_committee, shard in crosslink_committees_at_slot:
winning_root, attesting_validator_indices = get_winning_root_and_participants(
state=state,
shard=shard,
effective_balances=effective_balances,
committee_config=CommitteeConfig(config),
)
if len(attesting_validator_indices) > 0:
total_attesting_balance = get_total_balance(
state.validator_balances,
attesting_validator_indices,
config.MAX_DEPOSIT_AMOUNT,
)
total_balance = get_total_balance(
state.validator_balances,
crosslink_committee,
config.MAX_DEPOSIT_AMOUNT,
)
if 3 * total_attesting_balance >= 2 * total_balance:
latest_crosslinks = update_tuple_item(
latest_crosslinks,
shard,
CrosslinkRecord(
epoch=slot_to_epoch(Slot(slot),
config.SLOTS_PER_EPOCH),
crosslink_data_root=winning_root,
),
)
state = state.copy(latest_crosslinks=latest_crosslinks, )
return state
