def get_snapshot(stored_entity_id, event_store, until=None):
"""
Get the last snapshot for entity.
:rtype: Snapshot
"""
assert isinstance(event_store, AbstractEventStore)
snapshot_entity_id = make_stored_entity_id(id_prefix_from_event_class(Snapshot), stored_entity_id)
return event_store.get_most_recent_event(snapshot_entity_id, until=until)
def get_events(self, after=None, until=None, limit=None, is_ascending=False, page_size=None):
assert limit is None or limit > 0
if after is None:
after_timestamp = None
else:
after_timestamp = timestamp_from_uuid(after)
if until is None:
until_timestamp = None
else:
until_timestamp = timestamp_from_uuid(until)
now_timestamp = timestamp_from_uuid(uuid1())
started_on = self.log.started_on
if is_ascending:
# Start with the log start time, and continue until now.
timestamp = started_on if after is None else max(after_timestamp, started_on)
else:
timestamp = now_timestamp if until is None else min(until_timestamp, now_timestamp)
# Start counting events.
count_events = 0
while True:
entity_id = make_bucket_id(self.log.name, timestamp, self.log.bucket_size)
stored_entity_id = make_stored_entity_id('MessageLogged', entity_id)
for message_logged_event in self.event_store.get_entity_events(
stored_entity_id=stored_entity_id,
after=after,
until=until,
limit=limit,
is_ascending=is_ascending,
page_size=page_size,
):
yield message_logged_event
if limit is not None:
count_events += 1
if count_events >= limit:
raise StopIteration
# See if there's another bucket.
if is_ascending:
next_timestamp = next_bucket_starts(timestamp, self.log.bucket_size)
if next_timestamp > (until_timestamp or now_timestamp):
raise StopIteration
else:
timestamp = next_timestamp
else:
if timestamp < (after_timestamp or started_on):
raise StopIteration
else:
timestamp = previous_bucket_starts(timestamp, self.log.bucket_size)
def take_snapshot(entity, at_event_id):
# Make the 'stored entity ID' for the entity, it is used as the Snapshot 'entity ID'.
id_prefix = id_prefix_from_entity(entity)
stored_entity_id = make_stored_entity_id(id_prefix, entity.id)
# Create the snapshot event.
snapshot = Snapshot(
entity_id=stored_entity_id,
domain_event_id=at_event_id,
topic=topic_from_domain_class(entity.__class__),
attrs=entity.__dict__.copy(),
)
publish(snapshot)
# Return the event.
return snapshot
def make_stored_entity_id(self, entity_id):
"""Prefixes the given entity ID with the ID prefix for entity's type.
"""
return make_stored_entity_id(self.id_prefix, entity_id)
