def do_watch(self):
"""
Monitors the blockchain for channel breaches.
This is the main method of the :obj:`Watcher` and the one in charge to pass appointments to the
:obj:`Responder <teos.responder.Responder>` upon detecting a breach.
"""
# Distinguish fresh bootstraps from bootstraps from db
if self.last_known_block is None:
self.last_known_block = self.block_processor.get_best_block_hash()
self.db_manager.store_last_block_hash_watcher(
self.last_known_block)
# Initialise the locator cache with the last ``cache_size`` blocks.
self.locator_cache.init(self.last_known_block, self.block_processor)
while True:
block_hash = self.block_queue.get()
# When the ChainMonitor is stopped, a final ChainMonitor.END_MESSAGE message is sent
if block_hash == ChainMonitor.END_MESSAGE:
break
block = self.block_processor.get_block(block_hash)
self.logger.info("New block received",
block_hash=block_hash,
prev_block_hash=block.get("previousblockhash"))
# If a reorg is detected, the cache is fixed to cover the last `cache_size` blocks of the new chain
if self.last_known_block != block.get("previousblockhash"):
self.locator_cache.fix(block_hash, self.block_processor)
txids = block.get("tx")
# Compute the locator for every transaction in the block and add them to the cache
locator_txid_map = {compute_locator(txid): txid for txid in txids}
self.locator_cache.update(block_hash, locator_txid_map)
with self.rw_lock.gen_wlock():
if len(self.appointments) > 0 and locator_txid_map:
outdated_appointments = self.gatekeeper.get_outdated_appointments(
block["height"])
# Make sure we only try to delete what is on the Watcher (some appointments may have been triggered)
outdated_appointments = list(
set(outdated_appointments).intersection(
self.appointments.keys()))
Cleaner.delete_outdated_appointments(
outdated_appointments, self.appointments,
self.locator_uuid_map, self.db_manager)
valid_breaches, invalid_breaches = self.filter_breaches(
self.get_breaches(locator_txid_map))
triggered_flags = []
appointments_to_delete = []
for uuid, breach in valid_breaches.items():
self.logger.info(
"Notifying responder and deleting appointment",
penalty_txid=breach["penalty_txid"],
locator=breach["locator"],
uuid=uuid,
)
receipt = self.responder.handle_breach(
uuid,
breach["locator"],
breach["dispute_txid"],
breach["penalty_txid"],
breach["penalty_rawtx"],
self.appointments[uuid].get("user_id"),
block_hash,
)
# FIXME: Only necessary because of the triggered appointment approach. Fix if it changes.
if receipt.delivered:
Cleaner.delete_appointment_from_memory(
uuid, self.appointments, self.locator_uuid_map)
triggered_flags.append(uuid)
else:
appointments_to_delete.append(uuid)
# Appointments are only flagged as triggered if they are delivered, otherwise they are just deleted.
appointments_to_delete.extend(invalid_breaches)
appointments_to_delete_gatekeeper = {
uuid: self.appointments[uuid].get("user_id")
for uuid in appointments_to_delete
}
self.db_manager.batch_create_triggered_appointment_flag(
triggered_flags)
Cleaner.delete_completed_appointments(
appointments_to_delete, self.appointments,
self.locator_uuid_map, self.db_manager)
# Remove invalid appointments from the Gatekeeper
self.gatekeeper.delete_appointments(
appointments_to_delete_gatekeeper)
if not self.appointments:
self.logger.info("No more pending appointments")
# Register the last processed block for the Watcher
self.db_manager.store_last_block_hash_watcher(block_hash)
self.last_known_block = block.get("hash")
self.block_queue.task_done()
def do_watch(self):
"""
Monitors the blockchain whilst there are pending appointments.
This is the main method of the :obj:`Watcher` and the one in charge to pass appointments to the
:obj:`Responder <teos.responder.Responder>` upon detecting a breach.
"""
while True:
block_hash = self.block_queue.get()
block = self.block_processor.get_block(block_hash)
logger.info("New block received", block_hash=block_hash, prev_block_hash=block.get("previousblockhash"))
if len(self.appointments) > 0 and block is not None:
txids = block.get("tx")
expired_appointments = [
uuid
for uuid, appointment_data in self.appointments.items()
if block["height"] > appointment_data.get("end_time") + self.expiry_delta
]
Cleaner.delete_expired_appointments(
expired_appointments, self.appointments, self.locator_uuid_map, self.db_manager
)
valid_breaches, invalid_breaches = self.filter_valid_breaches(self.get_breaches(txids))
triggered_flags = []
appointments_to_delete = []
for uuid, breach in valid_breaches.items():
logger.info(
"Notifying responder and deleting appointment",
penalty_txid=breach["penalty_txid"],
locator=breach["locator"],
uuid=uuid,
)
receipt = self.responder.handle_breach(
uuid,
breach["locator"],
breach["dispute_txid"],
breach["penalty_txid"],
breach["penalty_rawtx"],
self.appointments[uuid].get("end_time"),
block_hash,
)
# FIXME: Only necessary because of the triggered appointment approach. Fix if it changes.
if receipt.delivered:
Cleaner.delete_appointment_from_memory(uuid, self.appointments, self.locator_uuid_map)
triggered_flags.append(uuid)
else:
appointments_to_delete.append(uuid)
# Appointments are only flagged as triggered if they are delivered, otherwise they are just deleted.
appointments_to_delete.extend(invalid_breaches)
self.db_manager.batch_create_triggered_appointment_flag(triggered_flags)
Cleaner.delete_completed_appointments(
appointments_to_delete, self.appointments, self.locator_uuid_map, self.db_manager
)
if len(self.appointments) is 0:
logger.info("No more pending appointments")
# Register the last processed block for the watcher
self.db_manager.store_last_block_hash_watcher(block_hash)
self.block_queue.task_done()