def process_transfers(state: BeaconState, block: BaseBeaconBlock,
config: Eth2Config) -> BeaconState:
if len(block.body.transfers) > config.MAX_TRANSFERS:
raise ValidationError(
f"The block ({block}) has too many transfers:\n"
f"\tFound {len(block.body.transfers)} transfers, "
f"maximum: {config.MAX_TRANSFERS}")
for transfer in block.body.transfers:
validate_transfer(
state,
transfer,
config,
)
state = decrease_balance(
state,
transfer.sender,
transfer.amount + transfer.fee,
)
state = increase_balance(
state,
transfer.recipient,
transfer.amount,
)
state = increase_balance(
state,
get_beacon_proposer_index(
state,
CommitteeConfig(config),
),
transfer.fee,
)
return state
def slash_validator(state: BeaconState,
index: ValidatorIndex,
config: Eth2Config,
whistleblower_index: ValidatorIndex = None) -> BeaconState:
"""
Slash the validator with index ``index``.
Exit the validator, penalize the validator, and reward the whistleblower.
"""
# NOTE: remove in phase 1
assert whistleblower_index is None
slots_per_epoch = config.SLOTS_PER_EPOCH
current_epoch = state.current_epoch(slots_per_epoch)
state = initiate_validator_exit(state, index, config)
state = state.update_validator_with_fn(
index,
_set_validator_slashed,
current_epoch,
config.EPOCHS_PER_SLASHINGS_VECTOR,
)
slashed_balance = state.validators[index].effective_balance
slashed_epoch = current_epoch % config.EPOCHS_PER_SLASHINGS_VECTOR
state = state.copy(slashings=update_tuple_item_with_fn(
state.slashings,
slashed_epoch,
lambda balance, slashed_balance: Gwei(balance + slashed_balance),
slashed_balance,
))
state = decrease_balance(
state, index, slashed_balance // config.MIN_SLASHING_PENALTY_QUOTIENT)
proposer_index = get_beacon_proposer_index(state, CommitteeConfig(config))
if whistleblower_index is None:
whistleblower_index = proposer_index
whistleblower_reward = Gwei(slashed_balance //
config.WHISTLEBLOWER_REWARD_QUOTIENT)
proposer_reward = Gwei(whistleblower_reward //
config.PROPOSER_REWARD_QUOTIENT)
state = increase_balance(state, proposer_index, proposer_reward)
state = increase_balance(
state,
whistleblower_index,
Gwei(whistleblower_reward - proposer_reward),
)
return state
def slash_validator(
state: BeaconState,
index: ValidatorIndex,
config: Eth2Config,
whistleblower_index: ValidatorIndex = None,
) -> BeaconState:
"""
Slash the validator with index ``index``.
Exit the validator, penalize the validator, and reward the whistleblower.
"""
# NOTE: remove in phase 1
assert whistleblower_index is None
slots_per_epoch = config.SLOTS_PER_EPOCH
current_epoch = state.current_epoch(slots_per_epoch)
state = initiate_validator_exit(state, index, config)
state = state.transform(
("validators", index),
partial(
_set_validator_slashed,
current_epoch=current_epoch,
epochs_per_slashings_vector=config.EPOCHS_PER_SLASHINGS_VECTOR,
),
)
slashed_balance = state.validators[index].effective_balance
slashed_epoch = current_epoch % config.EPOCHS_PER_SLASHINGS_VECTOR
state = state.transform(("slashings", slashed_epoch),
lambda balance: Gwei(balance + slashed_balance))
state = decrease_balance(
state, index, slashed_balance // config.MIN_SLASHING_PENALTY_QUOTIENT)
proposer_index = get_beacon_proposer_index(state, config)
if whistleblower_index is None:
whistleblower_index = proposer_index
whistleblower_reward = Gwei(slashed_balance //
config.WHISTLEBLOWER_REWARD_QUOTIENT)
proposer_reward = Gwei(whistleblower_reward //
config.PROPOSER_REWARD_QUOTIENT)
state = increase_balance(state, proposer_index, proposer_reward)
state = increase_balance(state, whistleblower_index,
Gwei(whistleblower_reward - proposer_reward))
return state
def process_rewards_and_penalties(
state: BeaconState, config: Eth2Config
) -> BeaconState:
current_epoch = state.current_epoch(config.SLOTS_PER_EPOCH)
if current_epoch == config.GENESIS_EPOCH:
return state
rewards_for_attestations, penalties_for_attestations = get_attestation_deltas(
state, config
)
rewards_for_crosslinks, penalties_for_crosslinks = get_crosslink_deltas(
state, config
)
for index in range(len(state.validators)):
index = ValidatorIndex(index)
state = increase_balance(
state,
index,
Gwei(rewards_for_attestations[index] + rewards_for_crosslinks[index]),
)
state = decrease_balance(
state,
index,
Gwei(penalties_for_attestations[index] + penalties_for_crosslinks[index]),
)
return state
def process_deposit(state: BeaconState,
deposit: Deposit,
config: Eth2Config) -> BeaconState:
"""
Process a deposit from Ethereum 1.0.
"""
validate_deposit_proof(state, deposit, DEPOSIT_CONTRACT_TREE_DEPTH)
# Increment the next deposit index we are expecting. Note that this
# needs to be done here because while the deposit contract will never
# create an invalid Merkle branch, it may admit an invalid deposit
# object, and we need to be able to skip over it
state = state.copy(
eth1_deposit_index=state.eth1_deposit_index + 1,
)
pubkey = deposit.data.pubkey
amount = deposit.data.amount
validator_pubkeys = tuple(v.pubkey for v in state.validators)
if pubkey not in validator_pubkeys:
# Verify the deposit signature (proof of possession) for new validators.
# Note: The deposit contract does not check signatures.
# Note: Deposits are valid across forks, thus the deposit domain
# is retrieved directly from `compute_domain`.
is_valid_proof_of_possession = bls.verify(
message_hash=deposit.data.signing_root,
pubkey=pubkey,
signature=deposit.data.signature,
domain=compute_domain(
SignatureDomain.DOMAIN_DEPOSIT,
),
)
if not is_valid_proof_of_possession:
return state
withdrawal_credentials = deposit.data.withdrawal_credentials
validator = Validator.create_pending_validator(
pubkey,
withdrawal_credentials,
amount,
config,
)
return state.copy(
validators=state.validators + (validator,),
balances=state.balances + (amount, ),
)
else:
index = ValidatorIndex(validator_pubkeys.index(pubkey))
return increase_balance(
state,
index,
amount,
)
def test_increase_balance(genesis_state, delta):
index = random.sample(range(len(genesis_state.validators)), 1)[0]
prior_balance = genesis_state.balances[index]
state = increase_balance(genesis_state, index, delta)
assert state.balances[index] == Gwei(prior_balance + delta)
