def get_or_create_with_retry(model: Type[Model], **kwargs: Any) -> Model:
try:
with non_nesting_atomic(using='control'):
model_object = model.objects.get_or_create_full_clean(**kwargs, )
except IntegrityError as exception:
if exception.__cause__.pgcode == pg_errorcodes.UNIQUE_VIOLATION:
model_object = model.objects.get_or_create_full_clean(**kwargs, )
else:
raise
except ValidationError:
with non_nesting_atomic(using='control'):
model_object = model.objects.get_or_create_full_clean(**kwargs, )
return model_object
def pre_process_message_related_subtasks(
client_message: Message,
client_public_key: bytes
) -> None:
"""
Function gets subtask_id (or more subtask id's if message is ForcePayment) from client message, starts transaction,
checks if state is active and subtask is timed out (in database query, if it is subtask is locked). If so, file
status is verified (check additional conditions in verify_file_status) and subtask's state is updated
"""
subtask_ids_list = [] # type: list
if isinstance(client_message, ForcePayment):
for subtask_result_accepted in client_message.subtask_results_accepted_list:
subtask_ids_list.append(subtask_result_accepted.subtask_id)
else:
subtask_ids_list = [client_message.subtask_id]
for subtask_id in subtask_ids_list:
with non_nesting_atomic(using='control'):
subtask = get_one_or_none(
model_or_query_set=Subtask.objects.select_for_update(),
subtask_id=subtask_id,
)
if subtask is None:
return
check_compatibility(subtask, client_public_key)
update_subtasks_states(subtask, client_public_key)
def test_that_decorated_function_called_in_transaction_should_rasie_exception(
self):
@non_nesting_atomic(using='control')
def wrapped_function():
pass
with non_nesting_atomic(using='control'):
with self.assertRaises(ConcentPendingTransactionError):
wrapped_function()
def init(self, network_nonce: int) -> None:
if not self._is_storage_initialized():
self._init_with_nonce(network_nonce)
return
# If nonce stored in GlobalTransactionState is lower than network_nonce
# this statement will update nonce in DatabaseTransactionStorage
if self._get_nonce() < network_nonce:
with non_nesting_atomic(using='control'):
global_transaction_state = GlobalTransactionState.objects.select_for_update(
).get(pk=0, )
global_transaction_state.nonce = network_nonce
global_transaction_state.full_clean()
global_transaction_state.save()
def discard_claim(deposit_claim: DepositClaim) -> bool:
""" This operation tells Bankster to discard the claim. Claim is simply removed, freeing the funds. """
assert isinstance(deposit_claim, DepositClaim)
with non_nesting_atomic(using='control'):
try:
DepositAccount.objects.select_for_update().get(
pk=deposit_claim.payer_deposit_account_id)
except DepositAccount.DoesNotExist:
assert False
if deposit_claim.tx_hash is None:
claim_removed = False
else:
deposit_claim.delete()
claim_removed = True
log(
logger,
f'After removing DepositClaim. Was DepositClaim removed: {claim_removed}. Tx_hash: {deposit_claim.tx_hash}',
subtask_id=deposit_claim.subtask_id,
)
return claim_removed
def set_nonce_sign_and_save_tx(self, sign_tx: Callable[[Transaction],
None],
tx: Transaction) -> None:
"""
Sets the next nonce for the transaction, invokes the callback for
signing and saves it to the storage.
"""
tx.nonce = self._get_nonce()
with non_nesting_atomic(using='control'):
global_transaction_state = self._get_locked_global_transaction_state(
)
sign_tx(tx)
logger.info(
'Saving transaction %s, nonce=%d',
encode_hex(tx.hash),
tx.nonce,
)
pending_ethereum_transaction = PendingEthereumTransaction(
nonce=tx.nonce,
gasprice=tx.gasprice,
startgas=tx.startgas,
value=tx.value,
v=tx.v,
r=tx.r,
s=tx.s,
data=tx.data,
to=tx.to,
)
pending_ethereum_transaction.full_clean()
pending_ethereum_transaction.save()
global_transaction_state.nonce += 1
global_transaction_state.full_clean()
global_transaction_state.save()
def update_all_timed_out_subtasks_of_a_client(client_public_key: bytes) -> None:
"""
Function looks for all subtasks in active state of client. All found subtasks are processed in separate transactions,
locked in database, file status is verified (check additional conditions in verify_file_status) and subtask's state
is updated in _update_timed_out_subtask
"""
encoded_client_public_key = b64encode(client_public_key)
clients_subtask_list = Subtask.objects.filter(
Q(requestor__public_key=encoded_client_public_key) | Q(provider__public_key=encoded_client_public_key),
state__in=[state.name for state in Subtask.ACTIVE_STATES],
)
# Check if files are uploaded for all clients subtasks. It is checked for all clients subtasks, not only timeouted.
for subtask in clients_subtask_list:
with non_nesting_atomic(using='control'):
Subtask.objects.select_for_update().filter(subtask_id=subtask.subtask_id)
verify_file_status(subtask=subtask, client_public_key=client_public_key)
# Subtask may change it's state to passive (RESULT UPLOADED) in verify_file_status. In this case there
# is no need to call _update_timed_out_subtask any more. Next_deadline will be set to None, so it is
# necessary to check it before checking if deadline is exceeded.
if subtask.next_deadline is not None and subtask.next_deadline <= parse_timestamp_to_utc_datetime(get_current_utc_timestamp()):
_update_timed_out_subtask(subtask)
def claim_deposit(
subtask_id: str,
concent_use_case: ConcentUseCase,
requestor_ethereum_address: str,
provider_ethereum_address: str,
subtask_cost: int,
requestor_public_key: bytes,
provider_public_key: bytes,
) -> Tuple[Optional[DepositClaim], Optional[DepositClaim]]:
"""
The purpose of this operation is to check whether the clients participating in a use case have enough funds in their
deposits to cover all the costs associated with the use case in the pessimistic scenario.
"""
assert isinstance(concent_use_case, ConcentUseCase)
assert isinstance(requestor_ethereum_address, str)
assert isinstance(provider_ethereum_address, str)
assert isinstance(subtask_cost, int) and subtask_cost > 0
assert concent_use_case in [
ConcentUseCase.FORCED_ACCEPTANCE,
ConcentUseCase.ADDITIONAL_VERIFICATION
]
assert len(requestor_ethereum_address) == ETHEREUM_ADDRESS_LENGTH
assert len(provider_ethereum_address) == ETHEREUM_ADDRESS_LENGTH
assert provider_ethereum_address != requestor_ethereum_address
validate_bytes_public_key(requestor_public_key, 'requestor_public_key')
validate_bytes_public_key(provider_public_key, 'provider_public_key')
validate_uuid(subtask_id)
is_claim_against_provider: bool = (
concent_use_case == ConcentUseCase.ADDITIONAL_VERIFICATION
and settings.ADDITIONAL_VERIFICATION_COST > 0)
# Bankster creates Client and DepositAccount objects (if they don't exist yet) for the requestor
# and also for the provider if there's a non-zero claim against his account.
# This is done in single database transaction.
requestor_client: Client = get_or_create_with_retry(
Client, public_key=requestor_public_key)
requestor_deposit_account: DepositAccount = get_or_create_with_retry(
DepositAccount,
client=requestor_client,
ethereum_address=requestor_ethereum_address,
)
if is_claim_against_provider:
provider_client: Client = get_or_create_with_retry(
Client, public_key=provider_public_key)
provider_deposit_account: DepositAccount = get_or_create_with_retry(
DepositAccount,
client=provider_client,
ethereum_address=provider_ethereum_address,
)
# Bankster asks SCI about the amount of funds available in requestor's deposit.
requestor_deposit = service.get_deposit_value(
client_eth_address=requestor_ethereum_address) # pylint: disable=no-value-for-parameter
# If the amount claimed from provider's deposit is non-zero,
# Bankster asks SCI about the amount of funds available in his deposit.
if is_claim_against_provider:
provider_deposit = service.get_deposit_value(
client_eth_address=provider_ethereum_address) # pylint: disable=no-value-for-parameter
# Bankster puts database locks on DepositAccount objects
# that will be used as payers in newly created DepositClaims.
with non_nesting_atomic(using='control'):
DepositAccount.objects.select_for_update().filter(
client=requestor_client,
ethereum_address=requestor_ethereum_address,
)
if is_claim_against_provider:
DepositAccount.objects.select_for_update().filter(
client=provider_client,
ethereum_address=provider_ethereum_address,
)
# Bankster sums the amounts of all existing DepositClaims that have the same payer as the one being processed.
aggregated_claims_against_requestor = DepositClaim.objects.filter(
payer_deposit_account=requestor_deposit_account).aggregate(
sum_of_existing_claims=Coalesce(Sum('amount'), 0))
# If the existing claims against requestor's deposit are greater or equal to his current deposit,
# we can't add a new claim.
if requestor_deposit <= aggregated_claims_against_requestor[
'sum_of_existing_claims']:
return (None, None)
# Deposit lock for requestor.
claim_against_requestor = DepositClaim(
subtask_id=subtask_id,
payee_ethereum_address=provider_ethereum_address,
amount=subtask_cost,
concent_use_case=concent_use_case,
payer_deposit_account=requestor_deposit_account,
)
claim_against_requestor.full_clean()
claim_against_requestor.save()
if is_claim_against_provider:
# Bankster sums the amounts of all existing DepositClaims where the provider is the payer.
aggregated_claims_against_provider = DepositClaim.objects.filter(
payer_deposit_account=provider_deposit_account).aggregate(
sum_of_existing_claims=Coalesce(Sum('amount'), 0))
# If the total of existing claims and the current claim is greater or equal to the current deposit,
# we can't add a new claim.
provider_obligations = aggregated_claims_against_provider[
'sum_of_existing_claims'] + settings.ADDITIONAL_VERIFICATION_COST
if provider_deposit <= provider_obligations:
claim_against_requestor.delete()
raise BanksterTooSmallProviderDepositError(
f'Provider deposit is {provider_deposit} (required: {provider_obligations}'
)
# Deposit lock for provider.
if is_claim_against_provider:
claim_against_provider = DepositClaim(
subtask_id=subtask_id,
payee_ethereum_address=ethereum_public_key_to_address(
settings.CONCENT_ETHEREUM_PUBLIC_KEY),
amount=settings.ADDITIONAL_VERIFICATION_COST,
concent_use_case=concent_use_case,
payer_deposit_account=provider_deposit_account,
)
claim_against_provider.full_clean()
claim_against_provider.save()
else:
claim_against_provider = None # type: ignore
return (claim_against_requestor, claim_against_provider)
def settle_overdue_acceptances(
requestor_ethereum_address: str,
provider_ethereum_address: str,
acceptances: List[SubtaskResultsAccepted],
requestor_public_key: bytes,
) -> DepositClaim:
"""
The purpose of this operation is to calculate the total amount that the requestor owes provider for completed
computations and transfer that amount from requestor's deposit.
The caller is responsible for making sure that the payment is legitimate and should be performed.
Bankster simply calculates the amount and executes it.
"""
assert isinstance(requestor_ethereum_address, str)
assert isinstance(provider_ethereum_address, str)
assert all([
isinstance(acceptance, SubtaskResultsAccepted)
for acceptance in acceptances
])
assert len(requestor_ethereum_address) == ETHEREUM_ADDRESS_LENGTH
assert len(provider_ethereum_address) == ETHEREUM_ADDRESS_LENGTH
assert provider_ethereum_address != requestor_ethereum_address
validate_list_of_transaction_timestamp(acceptances)
requestor_client: Client = get_or_create_with_retry(
Client, public_key=requestor_public_key)
requestor_deposit_account: DepositAccount = get_or_create_with_retry(
DepositAccount,
client=requestor_client,
ethereum_address=requestor_ethereum_address)
# Bankster asks SCI about the amount of funds available in requestor's deposit.
requestor_deposit_value = service.get_deposit_value(
client_eth_address=requestor_ethereum_address) # pylint: disable=no-value-for-parameter
# Bankster begins a database transaction and puts a database lock on the DepositAccount object.
with non_nesting_atomic(using='control'):
DepositAccount.objects.select_for_update().get(
pk=requestor_deposit_account.pk)
# Bankster sums the amounts of all existing DepositClaims that have the same payer as the one being processed.
sum_of_existing_requestor_claims = DepositClaim.objects.filter(
payer_deposit_account=requestor_deposit_account).aggregate(
sum_of_existing_claims=Coalesce(Sum('amount'), 0))
# Concent defines time T0 equal to oldest payment_ts from passed SubtaskResultAccepted messages from
# subtask_results_accepted_list.
oldest_payments_ts = min(subtask_results_accepted.payment_ts
for subtask_results_accepted in acceptances)
# Concent gets list of forced payments from payment API where T0 <= payment_ts + PAYMENT_DUE_TIME.
list_of_settlement_payments = service.get_list_of_payments( # pylint: disable=no-value-for-parameter
requestor_eth_address=requestor_ethereum_address,
provider_eth_address=provider_ethereum_address,
min_block_timestamp=oldest_payments_ts,
transaction_type=TransactionType.SETTLEMENT,
)
already_satisfied_claims_without_duplicates = find_unconfirmed_settlement_payments(
list_of_settlement_payments,
requestor_deposit_account,
provider_ethereum_address,
oldest_payments_ts,
)
# Concent gets list of transactions from payment API where timestamp >= T0.
list_of_transactions = service.get_list_of_payments( # pylint: disable=no-value-for-parameter
requestor_eth_address=requestor_ethereum_address,
provider_eth_address=provider_ethereum_address,
min_block_timestamp=oldest_payments_ts,
transaction_type=TransactionType.BATCH,
)
(_amount_paid, amount_pending) = get_provider_payment_info(
list_of_settlement_payments=list_of_settlement_payments,
list_of_transactions=list_of_transactions,
settlement_payment_claims=
already_satisfied_claims_without_duplicates,
subtask_results_accepted_list=acceptances,
)
if amount_pending <= 0:
raise BanksterNoUnsettledTasksError()
# Bankster compares the amount with the available deposit minus the existing claims against requestor's account.
# If the whole amount can't be paid, Concent lowers it to pay as much as possible.
requestor_payable_amount = min(
amount_pending,
requestor_deposit_value -
sum_of_existing_requestor_claims['sum_of_existing_claims'],
)
logger.info(
f'requestor_payable_amount is {requestor_payable_amount} for ethereum address {requestor_ethereum_address}.'
)
if requestor_payable_amount <= 0:
raise BanksterTooSmallRequestorDepositError(
f"Requestor payable amount is {requestor_payable_amount}")
# This is time T2 (end time) equal to youngest payment_ts from passed SubtaskResultAccepted messages from
# subtask_results_accepted_list.
youngest_payment_ts = max(subtask_results_accepted.payment_ts
for subtask_results_accepted in acceptances)
# Deposit lock for requestor.
claim_against_requestor = DepositClaim(
payee_ethereum_address=provider_ethereum_address,
payer_deposit_account=requestor_deposit_account,
amount=requestor_payable_amount,
concent_use_case=ConcentUseCase.FORCED_PAYMENT,
tx_hash=None,
closure_time=parse_timestamp_to_utc_datetime(youngest_payment_ts),
)
claim_against_requestor.full_clean()
claim_against_requestor.save()
v_list, r_list, s_list, values, subtask_id_list = [], [], [], [], []
for subtask_results_accepted in acceptances:
v, r, s = subtask_results_accepted.task_to_compute.promissory_note_sig
v_list.append(v)
r_list.append(r)
s_list.append(s)
values.append(subtask_results_accepted.task_to_compute.price)
subtask_id_list.append(
subtask_results_accepted.task_to_compute.subtask_id)
transaction_hash = service.make_settlement_payment( # pylint: disable=no-value-for-parameter
requestor_eth_address=requestor_ethereum_address,
provider_eth_address=provider_ethereum_address,
value=values,
subtask_ids=subtask_id_list,
closure_time=youngest_payment_ts,
v=v_list,
r=r_list,
s=s_list,
reimburse_amount=claim_against_requestor.amount_as_int,
)
transaction_hash = adjust_transaction_hash(transaction_hash)
with non_nesting_atomic(using='control'):
claim_against_requestor.tx_hash = transaction_hash
claim_against_requestor.full_clean()
claim_against_requestor.save()
return claim_against_requestor
def finalize_payment(deposit_claim: DepositClaim) -> Optional[str]:
"""
This operation tells Bankster to pay out funds from deposit.
For each claim, Bankster uses SCI to submit an Ethereum transaction to the Ethereum client which then propagates it
to the rest of the network.
Hopefully the transaction is included in one of the upcoming blocks on the blockchain.
IMPORTANT!: This function must never be called in parallel for the same DepositClaim - otherwise provider might get
paid twice for the same thing. It's caller responsibility to ensure that.
"""
assert isinstance(deposit_claim, DepositClaim)
assert deposit_claim.tx_hash is None
# Bankster asks SCI about the amount of funds available on the deposit account listed in the DepositClaim.
available_funds = service.get_deposit_value( # pylint: disable=no-value-for-parameter
client_eth_address=deposit_claim.payer_deposit_account.ethereum_address
)
# Bankster begins a database transaction and puts a database lock on the DepositAccount object.
with non_nesting_atomic(using='control'):
DepositAccount.objects.select_for_update().get(
pk=deposit_claim.payer_deposit_account_id)
# Bankster sums the amounts of all existing DepositClaims that have the same payer as the one being processed.
aggregated_client_claims = DepositClaim.objects.filter(
payer_deposit_account=deposit_claim.payer_deposit_account).exclude(
pk=deposit_claim.pk).aggregate(
sum_of_existing_claims=Coalesce(Sum('amount'), 0))
# Bankster subtracts that value from the amount of funds available in the deposit.
available_funds_without_claims = available_funds - aggregated_client_claims[
'sum_of_existing_claims']
# If the result is negative or zero, Bankster removes the DepositClaim object being processed.
if available_funds_without_claims <= 0:
deposit_claim.delete()
return None
# Otherwise if the result is lower than DepositAccount.amount,
# Bankster sets this field to the amount that's actually available.
elif available_funds_without_claims < deposit_claim.amount:
deposit_claim.amount = available_funds_without_claims
deposit_claim.save()
# If the DepositClaim still exists at this point, Bankster uses SCI to create an Ethereum transaction.
subtask = Subtask.objects.filter(
subtask_id=deposit_claim.subtask_id).first() # pylint: disable=no-member
task_to_compute: TaskToCompute = deserialize_message(
subtask.task_to_compute.data.tobytes())
v, r, s = task_to_compute.promissory_note_sig
if deposit_claim.concent_use_case == ConcentUseCase.FORCED_ACCEPTANCE:
ethereum_transaction_hash = service.force_subtask_payment( # pylint: disable=no-value-for-parameter
requestor_eth_address=deposit_claim.payer_deposit_account.
ethereum_address,
provider_eth_address=deposit_claim.payee_ethereum_address,
value=task_to_compute.price,
subtask_id=deposit_claim.subtask_id,
v=v,
r=r,
s=s,
reimburse_amount=deposit_claim.amount_as_int,
)
elif deposit_claim.concent_use_case == ConcentUseCase.ADDITIONAL_VERIFICATION:
if subtask is not None:
if task_to_compute.requestor_ethereum_address == deposit_claim.payer_deposit_account.ethereum_address:
ethereum_transaction_hash = service.force_subtask_payment( # pylint: disable=no-value-for-parameter
requestor_eth_address=deposit_claim.payer_deposit_account.
ethereum_address,
provider_eth_address=deposit_claim.payee_ethereum_address,
value=task_to_compute.price,
subtask_id=deposit_claim.subtask_id,
v=v,
r=r,
s=s,
reimburse_amount=deposit_claim.amount_as_int,
)
elif task_to_compute.provider_ethereum_address == deposit_claim.payer_deposit_account.ethereum_address:
subtask_results_verify: SubtaskResultsVerify = deserialize_message(
subtask.subtask_results_verify.data.tobytes())
(v, r, s) = subtask_results_verify.concent_promissory_note_sig
ethereum_transaction_hash = service.cover_additional_verification_cost( # pylint: disable=no-value-for-parameter
provider_eth_address=deposit_claim.payer_deposit_account.
ethereum_address,
value=subtask_results_verify.task_to_compute.price,
subtask_id=deposit_claim.subtask_id,
v=v,
r=r,
s=s,
reimburse_amount=deposit_claim.amount_as_int,
)
else:
assert False
else:
assert False
with non_nesting_atomic(using='control'):
# The code below is executed in another transaction, so - in theory - deposit_claim object could be modified in
# the meantime. Here we are working under assumption that it's not the case and it is coder's responsibility to
# ensure that.
ethereum_transaction_hash = adjust_transaction_hash(
ethereum_transaction_hash)
deposit_claim.tx_hash = ethereum_transaction_hash
deposit_claim.full_clean()
deposit_claim.save()
service.register_confirmed_transaction_handler( # pylint: disable=no-value-for-parameter
tx_hash=deposit_claim.tx_hash,
callback=lambda _: discard_claim(deposit_claim),
)
return deposit_claim.tx_hash
def test_that_non_nesting_atomic_decorator_will_not_raise_exception_if_transaction_is_nested_using_same_databases_and_detect_nested_transaction_setting_is_false(
self):
with non_nesting_atomic(using='control'):
with non_nesting_atomic(using='control'):
self.assertTrue(get_connection('control').in_atomic_block)
def test_that_non_nesting_atomic_decorator_will_not_raise_exception_if_transaction_is_nested_using_different_databases(
self): # pylint: disable=no-self-use
with non_nesting_atomic(using='control'):
with non_nesting_atomic(using='storage'):
self.assertTrue(get_connection('control').in_atomic_block)
self.assertTrue(get_connection('storage').in_atomic_block)
def test_that_non_nesting_atomic_decorator_will_raise_exception_if_transaction_is_nested_using_same_database(
self):
with non_nesting_atomic(using='control'):
with self.assertRaises(ConcentPendingTransactionError):
with non_nesting_atomic(using='control'):
pass
