class PathfindingService(gevent.Greenlet):
# pylint: disable=too-many-instance-attributes
def __init__( # pylint: disable=too-many-arguments
self,
web3: Web3,
contracts: Dict[str, Contract],
private_key: PrivateKey,
db_filename: str,
sync_start_block: BlockNumber,
required_confirmations: BlockTimeout,
poll_interval: float,
matrix_servers: Optional[List[str]] = None,
):
super().__init__()
self.web3 = web3
self.registry_address = contracts[
CONTRACT_TOKEN_NETWORK_REGISTRY].address
self.user_deposit_contract = contracts[CONTRACT_USER_DEPOSIT]
self.service_token_address = self.user_deposit_contract.functions.token(
).call()
self.chain_id = ChainID(web3.eth.chainId)
self.address = private_key_to_address(private_key)
self.required_confirmations = required_confirmations
self._poll_interval = poll_interval
self._is_running = gevent.event.Event()
log.info("PFS payment address", address=self.address)
self.database = PFSDatabase(
filename=db_filename,
pfs_address=self.address,
sync_start_block=sync_start_block,
token_network_registry_address=to_canonical_address(
self.registry_address),
chain_id=self.chain_id,
user_deposit_contract_address=to_canonical_address(
self.user_deposit_contract.address),
allow_create=True,
)
self.blockchain_state = BlockchainState(
latest_committed_block=self.database.get_latest_committed_block(),
token_network_registry_address=to_canonical_address(
self.registry_address),
chain_id=self.chain_id,
)
self.matrix_listener = MatrixListener(
private_key=private_key,
chain_id=self.chain_id,
device_id=DeviceIDs.PFS,
message_received_callback=self.handle_message,
servers=matrix_servers,
)
self.token_networks = self._load_token_networks()
self.updated = gevent.event.Event(
) # set whenever blocks are processed
self.startup_finished = gevent.event.AsyncResult()
self._init_metrics()
def _init_metrics(self) -> None:
def _get_number_of_claimed_ious() -> float:
return float(self.database.get_nof_claimed_ious())
def _get_total_amount_of_claimed_ious() -> float:
return float(sum(iou.amount for iou in self._iter_claimed_ious()))
metrics.get_metrics_for_label(
metrics.IOU_CLAIMS, metrics.IouStatus.SUCCESSFUL).set_function(
_get_number_of_claimed_ious)
metrics.get_metrics_for_label(
metrics.IOU_CLAIMS_TOKEN,
metrics.IouStatus.SUCCESSFUL).set_function(
_get_total_amount_of_claimed_ious)
def _iter_claimed_ious(self) -> Iterator[IOU]:
return self.database.get_ious(claimed=True)
def _load_token_networks(self) -> Dict[TokenNetworkAddress, TokenNetwork]:
network_for_address = {
n.address: n
for n in self.database.get_token_networks()
}
for channel in self.database.get_channels():
for cv in channel.views:
network_for_address[cv.token_network_address].add_channel_view(
cv)
return network_for_address
def _run(self) -> None: # pylint: disable=method-hidden
try:
self.matrix_listener.start()
except (Timeout, ConnectionError) as exc:
log.critical("Could not connect to broadcasting system.", exc=exc)
sys.exit(1)
self.matrix_listener.link(self.startup_finished)
try:
self.matrix_listener.startup_finished.get(
timeout=MATRIX_START_TIMEOUT)
except Timeout:
raise Exception("MatrixListener did not start in time.")
self.startup_finished.set()
log.info(
"Listening to token network registry",
registry_address=self.registry_address,
start_block=self.database.get_latest_committed_block(),
)
while not self._is_running.is_set():
self._process_new_blocks(
BlockNumber(self.web3.eth.blockNumber -
self.required_confirmations))
# Let tests waiting for this event know that we're done with processing
self.updated.set()
self.updated.clear()
# Sleep, then collect errors from greenlets
gevent.sleep(self._poll_interval)
gevent.joinall({self.matrix_listener}, timeout=0, raise_error=True)
def _process_new_blocks(self, latest_confirmed_block: BlockNumber) -> None:
start = time.monotonic()
db_block = self.database.get_latest_committed_block()
assert db_block == self.blockchain_state.latest_committed_block, (
f"Unexpected `latest_committed_block` in db: "
f"was {db_block}, expected {self.blockchain_state.latest_committed_block}. "
f"Is the db accidentally shared by two PFSes?")
events = get_blockchain_events_adaptive(
web3=self.web3,
blockchain_state=self.blockchain_state,
token_network_addresses=list(self.token_networks.keys()),
latest_confirmed_block=latest_confirmed_block,
)
if events is None:
return
before_process = time.monotonic()
for event in events:
self.handle_event(event)
gevent.idle() # Allow answering requests in between events
if events:
log.info(
"Processed events",
getting=round(before_process - start, 2),
processing=round(time.monotonic() - before_process, 2),
total_duration=round(time.monotonic() - start, 2),
event_counts=collections.Counter(e.__class__.__name__
for e in events),
)
def stop(self) -> None:
self.matrix_listener.kill()
self._is_running.set()
self.matrix_listener.join()
def follows_token_network(
self, token_network_address: TokenNetworkAddress) -> bool:
"""Checks if a token network is followed by the pathfinding service."""
return token_network_address in self.token_networks.keys()
def get_token_network(
self, token_network_address: TokenNetworkAddress
) -> Optional[TokenNetwork]:
"""Returns the `TokenNetwork` for the given address or `None` for unknown networks."""
return self.token_networks.get(token_network_address)
def handle_event(self, event: Event) -> None:
with sentry_sdk.configure_scope() as scope:
with metrics.collect_event_metrics(event):
scope.set_extra("event", event)
if isinstance(event, ReceiveTokenNetworkCreatedEvent):
self.handle_token_network_created(event)
elif isinstance(event, ReceiveChannelOpenedEvent):
self.handle_channel_opened(event)
elif isinstance(event, ReceiveChannelClosedEvent):
self.handle_channel_closed(event)
elif isinstance(event, UpdatedHeadBlockEvent):
# TODO: Store blockhash here as well
self.blockchain_state.latest_committed_block = event.head_block_number
self.database.update_lastest_committed_block(
event.head_block_number)
else:
log.debug("Unhandled event", evt=event)
def handle_token_network_created(
self, event: ReceiveTokenNetworkCreatedEvent) -> None:
network_address = event.token_network_address
if not self.follows_token_network(network_address):
log.info("Found new token network", event_=event)
self.token_networks[network_address] = TokenNetwork(
network_address)
self.database.upsert_token_network(network_address)
def handle_channel_opened(self, event: ReceiveChannelOpenedEvent) -> None:
token_network = self.get_token_network(event.token_network_address)
if token_network is None:
return
log.info("Received ChannelOpened event", event_=event)
channel = token_network.handle_channel_opened_event(
channel_identifier=event.channel_identifier,
participant1=event.participant1,
participant2=event.participant2,
settle_timeout=event.settle_timeout,
)
self.database.upsert_channel(channel)
# Handle messages for this channel which where received before ChannelOpened
with self.database.conn:
for message in self.database.pop_waiting_messages(
token_network_address=token_network.address,
channel_id=event.channel_identifier):
log.debug("Processing deferred message", message=message)
self.handle_message(message)
def handle_channel_closed(self, event: ReceiveChannelClosedEvent) -> None:
token_network = self.get_token_network(event.token_network_address)
if token_network is None:
return
log.info("Received ChannelClosed event", event_=event)
channel_deleted = self.database.delete_channel(
event.token_network_address, event.channel_identifier)
if channel_deleted:
token_network.handle_channel_closed_event(event.channel_identifier)
else:
log.error(
"Received ChannelClosed event for unknown channel",
token_network_address=event.token_network_address,
channel_identifier=event.channel_identifier,
)
metrics.get_metrics_for_label(metrics.ERRORS_LOGGED,
metrics.ErrorCategory.STATE).inc()
def handle_message(self, message: Message) -> None:
with sentry_sdk.configure_scope() as scope:
scope.set_extra("message", message)
try:
with metrics.collect_message_metrics(message):
if isinstance(message, PFSCapacityUpdate):
changed_channel: Optional[
Channel] = self.on_capacity_update(message)
elif isinstance(message, PFSFeeUpdate):
changed_channel = self.on_fee_update(message)
else:
log.debug("Ignoring message", unknown_message=message)
return
if changed_channel:
self.database.upsert_channel(changed_channel)
except DeferMessage as ex:
self.defer_message_until_channel_is_open(ex.deferred_message)
except InvalidGlobalMessage as ex:
log.info(str(ex), **asdict(message))
def defer_message_until_channel_is_open(self,
message: DeferableMessage) -> None:
log.debug(
"Received message for unknown channel, defer until ChannelOpened is confirmed",
channel_id=message.canonical_identifier.channel_identifier,
message=message,
)
self.database.insert_waiting_message(message)
def _validate_pfs_fee_update(self, message: PFSFeeUpdate) -> TokenNetwork:
# check if chain_id matches
if message.canonical_identifier.chain_identifier != self.chain_id:
raise InvalidFeeUpdate(
"Received Fee Update with unknown chain identifier")
# check if token network exists
token_network = self.get_token_network(
message.canonical_identifier.token_network_address)
if token_network is None:
raise InvalidFeeUpdate(
"Received Fee Update with unknown token network")
# check signature of Capacity Update
if message.sender != message.updating_participant:
raise InvalidFeeUpdate("Fee Update not signed correctly")
# check if channel exists
channel_identifier = message.canonical_identifier.channel_identifier
if channel_identifier not in token_network.channel_id_to_addresses:
raise DeferMessage(message)
# check if participants fit to channel id
participants = token_network.channel_id_to_addresses[
channel_identifier]
if message.updating_participant not in participants:
raise InvalidFeeUpdate(
"Sender of Fee Update does not match the internal channel")
# check that timestamp has no timezone
if message.timestamp.tzinfo is not None:
raise InvalidFeeUpdate(
"Timestamp of Fee Update should not contain timezone")
return token_network
def on_fee_update(self, message: PFSFeeUpdate) -> Optional[Channel]:
token_network = self._validate_pfs_fee_update(message)
log.debug("Received Fee Update", message=message)
return token_network.handle_channel_fee_update(message)
def _validate_pfs_capacity_update(
self, message: PFSCapacityUpdate) -> TokenNetwork:
# check if chain_id matches
if message.canonical_identifier.chain_identifier != self.chain_id:
raise InvalidCapacityUpdate(
"Received Capacity Update with unknown chain identifier")
# check if token network exists
token_network = self.get_token_network(
message.canonical_identifier.token_network_address)
if token_network is None:
raise InvalidCapacityUpdate(
"Received Capacity Update with unknown token network")
# check values < max int 256
if message.updating_capacity > UINT256_MAX:
raise InvalidCapacityUpdate(
"Received Capacity Update with impossible updating_capacity")
if message.other_capacity > UINT256_MAX:
raise InvalidCapacityUpdate(
"Received Capacity Update with impossible other_capacity")
# check signature of Capacity Update
if message.sender != message.updating_participant:
raise InvalidCapacityUpdate("Capacity Update not signed correctly")
# check if channel exists
channel_identifier = message.canonical_identifier.channel_identifier
if channel_identifier not in token_network.channel_id_to_addresses:
raise DeferMessage(message)
# check if participants fit to channel id
participants = token_network.channel_id_to_addresses[
channel_identifier]
if message.updating_participant not in participants:
raise InvalidCapacityUpdate(
"Sender of Capacity Update does not match the internal channel"
)
if message.other_participant not in participants:
raise InvalidCapacityUpdate(
"Other Participant of Capacity Update does not match the internal channel"
)
return token_network
def on_capacity_update(self, message: PFSCapacityUpdate) -> Channel:
token_network = self._validate_pfs_capacity_update(message)
log.debug("Received Capacity Update", message=message)
self.database.upsert_capacity_update(message)
updating_capacity_partner, other_capacity_partner = self.database.get_capacity_updates(
updating_participant=message.other_participant,
token_network_address=TokenNetworkAddress(
message.canonical_identifier.token_network_address),
channel_id=message.canonical_identifier.channel_identifier,
)
return token_network.handle_channel_balance_update_message(
message=message,
updating_capacity_partner=updating_capacity_partner,
other_capacity_partner=other_capacity_partner,
)
class PathfindingService(gevent.Greenlet):
# pylint: disable=too-many-instance-attributes
def __init__( # pylint: disable=too-many-arguments
self,
web3: Web3,
contracts: Dict[str, Contract],
private_key: str,
db_filename: str,
sync_start_block: BlockNumber = BlockNumber(0),
required_confirmations: int = 8,
poll_interval: float = 10,
matrix_servers: List[str] = None,
):
super().__init__()
self.web3 = web3
self.registry_address = contracts[
CONTRACT_TOKEN_NETWORK_REGISTRY].address
self.user_deposit_contract = contracts[CONTRACT_USER_DEPOSIT]
self.chain_id = ChainID(int(web3.net.version))
self.address = private_key_to_address(private_key)
self.required_confirmations = required_confirmations
self._poll_interval = poll_interval
self._is_running = gevent.event.Event()
log.info("PFS payment address", address=self.address)
self.blockchain_state = BlockchainState(
latest_commited_block=BlockNumber(0),
token_network_registry_address=self.registry_address,
chain_id=self.chain_id,
)
self.database = PFSDatabase(
filename=db_filename,
pfs_address=self.address,
sync_start_block=sync_start_block,
token_network_registry_address=self.registry_address,
chain_id=self.chain_id,
user_deposit_contract_address=self.user_deposit_contract.address,
allow_create=True,
)
self.matrix_listener = MatrixListener(
private_key=private_key,
chain_id=self.chain_id,
service_room_suffix=PATH_FINDING_BROADCASTING_ROOM,
message_received_callback=self.handle_message,
address_reachability_changed_callback=self.
handle_reachability_change,
servers=matrix_servers,
)
self.address_to_reachability: Dict[Address,
AddressReachability] = dict()
self.token_networks = self._load_token_networks()
def _load_token_networks(self) -> Dict[TokenNetworkAddress, TokenNetwork]:
network_for_address = {
n.address: n
for n in self.database.get_token_networks()
}
for channel in self.database.get_channels():
for cv in channel.views:
network_for_address[cv.token_network_address].add_channel_view(
cv)
# Register channel participants for presence tracking
self.matrix_listener.follow_address_presence(channel.participant1)
self.matrix_listener.follow_address_presence(channel.participant2)
return network_for_address
def _run(self) -> None: # pylint: disable=method-hidden
register_error_handler()
try:
self.matrix_listener.start()
assert self.matrix_listener.startup_finished.wait(
timeout=MATRIX_START_TIMEOUT
), "MatrixListener did not start in time."
except (Timeout, ConnectionError) as exc:
log.critical("Could not connect to broadcasting system.", exc=exc)
sys.exit(1)
log.info(
"Listening to token network registry",
registry_address=self.registry_address,
start_block=self.database.get_latest_commited_block(),
)
while not self._is_running.is_set():
last_confirmed_block = self.web3.eth.blockNumber - self.required_confirmations
max_query_interval_end_block = (
self.database.get_latest_commited_block() +
MAX_FILTER_INTERVAL)
# Limit the max number of blocks that is processed per iteration
last_block = min(last_confirmed_block,
max_query_interval_end_block)
self._process_new_blocks(last_block)
try:
gevent.sleep(self._poll_interval)
except KeyboardInterrupt:
log.info("Shutting down")
sys.exit(0)
def _process_new_blocks(self, last_block: BlockNumber) -> None:
self.blockchain_state.latest_commited_block = self.database.get_latest_commited_block(
)
self.blockchain_state.token_network_addresses = list(
self.token_networks.keys())
_, events = get_blockchain_events(
web3=self.web3,
contract_manager=CONTRACT_MANAGER,
chain_state=self.blockchain_state,
to_block=last_block,
)
for event in events:
self.handle_event(event)
def stop(self) -> None:
self.matrix_listener.stop()
self._is_running.set()
self.matrix_listener.join()
def follows_token_network(
self, token_network_address: TokenNetworkAddress) -> bool:
""" Checks if a token network is followed by the pathfinding service. """
return token_network_address in self.token_networks.keys()
def handle_reachability_change(self, address: Address,
reachability: AddressReachability) -> None:
self.address_to_reachability[address] = reachability
def get_token_network(
self, token_network_address: TokenNetworkAddress
) -> Optional[TokenNetwork]:
""" Returns the `TokenNetwork` for the given address or `None` for unknown networks. """
return self.token_networks.get(token_network_address)
def handle_event(self, event: Event) -> None:
if isinstance(event, ReceiveTokenNetworkCreatedEvent):
self.handle_token_network_created(event)
elif isinstance(event, ReceiveChannelOpenedEvent):
self.handle_channel_opened(event)
elif isinstance(event, ReceiveChannelClosedEvent):
self.handle_channel_closed(event)
elif isinstance(event, UpdatedHeadBlockEvent):
self.database.update_lastest_committed_block(
event.head_block_number)
else:
log.debug("Unhandled event", evt=event)
def handle_token_network_created(
self, event: ReceiveTokenNetworkCreatedEvent) -> None:
network_address = TokenNetworkAddress(event.token_network_address)
if not self.follows_token_network(network_address):
log.info("Found new token network", event_=event)
self.token_networks[network_address] = TokenNetwork(
network_address)
self.database.upsert_token_network(network_address)
def handle_channel_opened(self, event: ReceiveChannelOpenedEvent) -> None:
token_network = self.get_token_network(event.token_network_address)
if token_network is None:
return
log.info("Received ChannelOpened event", event_=event)
self.matrix_listener.follow_address_presence(event.participant1,
refresh=True)
self.matrix_listener.follow_address_presence(event.participant2,
refresh=True)
channel = token_network.handle_channel_opened_event(
channel_identifier=event.channel_identifier,
participant1=event.participant1,
participant2=event.participant2,
settle_timeout=event.settle_timeout,
)
self.database.upsert_channel(channel)
# Handle messages for this channel which where received before ChannelOpened
with self.database.conn:
for message in self.database.pop_waiting_messages(
token_network_address=token_network.address,
channel_id=event.channel_identifier):
self.handle_message(message)
def handle_channel_closed(self, event: ReceiveChannelClosedEvent) -> None:
token_network = self.get_token_network(event.token_network_address)
if token_network is None:
return
log.info("Received ChannelClosed event", event_=event)
token_network.handle_channel_closed_event(
channel_identifier=event.channel_identifier)
self.database.delete_channel(event.token_network_address,
event.channel_identifier)
def handle_message(self, message: Message) -> None:
try:
if isinstance(message, PFSCapacityUpdate):
changed_channel: Optional[Channel] = self.on_capacity_update(
message)
elif isinstance(message, PFSFeeUpdate):
changed_channel = self.on_fee_update(message)
else:
log.debug("Ignoring message", unknown_message=message)
return
if changed_channel:
self.database.upsert_channel(changed_channel)
except DeferMessage as ex:
self.defer_message_until_channel_is_open(ex.deferred_message)
except InvalidGlobalMessage as ex:
log.info(str(ex), **asdict(message))
def defer_message_until_channel_is_open(self,
message: DeferableMessage) -> None:
log.debug(
"Received message for unknown channel, defer until ChannelOpened is confirmed",
channel_id=message.canonical_identifier.channel_identifier,
message=message,
)
self.database.insert_waiting_message(message)
def on_fee_update(self, message: PFSFeeUpdate) -> Optional[Channel]:
if message.sender != message.updating_participant:
raise InvalidPFSFeeUpdate(
"Invalid sender recovered from signature in PFSFeeUpdate")
token_network = self.get_token_network(
message.canonical_identifier.token_network_address)
if not token_network:
return None
log.debug("Received Fee Update", message=message)
if (message.canonical_identifier.channel_identifier
not in token_network.channel_id_to_addresses):
raise DeferMessage(message)
return token_network.handle_channel_fee_update(message)
def _validate_pfs_capacity_update(
self, message: PFSCapacityUpdate) -> TokenNetwork:
token_network_address = TokenNetworkAddress(
message.canonical_identifier.token_network_address)
# check if chain_id matches
if message.canonical_identifier.chain_identifier != self.chain_id:
raise InvalidCapacityUpdate(
"Received Capacity Update with unknown chain identifier")
# check if token network exists
token_network = self.get_token_network(token_network_address)
if token_network is None:
raise InvalidCapacityUpdate(
"Received Capacity Update with unknown token network")
# check values < max int 256
if message.updating_capacity > UINT256_MAX:
raise InvalidCapacityUpdate(
"Received Capacity Update with impossible updating_capacity")
if message.other_capacity > UINT256_MAX:
raise InvalidCapacityUpdate(
"Received Capacity Update with impossible other_capacity")
# check signature of Capacity Update
if message.sender != message.updating_participant:
raise InvalidCapacityUpdate("Capacity Update not signed correctly")
# check if channel exists
channel_identifier = message.canonical_identifier.channel_identifier
if channel_identifier not in token_network.channel_id_to_addresses:
raise DeferMessage(message)
# check if participants fit to channel id
participants = token_network.channel_id_to_addresses[
channel_identifier]
if message.updating_participant not in participants:
raise InvalidCapacityUpdate(
"Sender of Capacity Update does not match the internal channel"
)
if message.other_participant not in participants:
raise InvalidCapacityUpdate(
"Other Participant of Capacity Update does not match the internal channel"
)
return token_network
def on_capacity_update(self, message: PFSCapacityUpdate) -> Channel:
token_network = self._validate_pfs_capacity_update(message)
log.debug("Received Capacity Update", message=message)
self.database.upsert_capacity_update(message)
# Follow presence for the channel participants
self.matrix_listener.follow_address_presence(
message.updating_participant, refresh=True)
self.matrix_listener.follow_address_presence(message.other_participant,
refresh=True)
updating_capacity_partner, other_capacity_partner = self.database.get_capacity_updates(
updating_participant=message.other_participant,
token_network_address=TokenNetworkAddress(
message.canonical_identifier.token_network_address),
channel_id=message.canonical_identifier.channel_identifier,
)
return token_network.handle_channel_balance_update_message(
message=message,
updating_capacity_partner=updating_capacity_partner,
other_capacity_partner=other_capacity_partner,
)
