def test_entity_lifecycle(self):
# Check the factory creates an instance.
example1 = register_new_example(a=1, b=2)
self.assertIsInstance(example1, Example)
self.assertEqual(1, example1.a)
self.assertEqual(2, example1.b)
# Check a second instance with the same values is not "equal" to the first.
example2 = register_new_example(a=1, b=2)
self.assertNotEqual(example1, example2)
# Setup the repo.
repo = ExampleRepository(self.event_store)
# Check the example entities can be retrieved from the example repository.
entity1 = repo[example1.id]
self.assertIsInstance(entity1, Example)
self.assertEqual(1, entity1.a)
self.assertEqual(2, entity1.b)
entity2 = repo[example2.id]
self.assertIsInstance(entity2, Example)
self.assertEqual(1, entity2.a)
self.assertEqual(2, entity2.b)
# Check the entity can be updated.
entity1.a = 100
self.assertEqual(100, repo[entity1.id].a)
entity1.b = -200
self.assertEqual(-200, repo[entity1.id].b)
self.assertEqual(0, entity1.count_heartbeats())
entity1.beat_heart()
entity1.beat_heart()
entity1.beat_heart()
self.assertEqual(3, entity1.count_heartbeats())
self.assertEqual(3, repo[entity1.id].count_heartbeats())
# Check the entity can be discarded.
entity1.discard()
self.assertRaises(KeyError, repo.__getitem__, entity1.id)
def test_with_snapshots(self):
# Check the EventPlayer's take_snapshot() method.
stored_event_repo = PythonObjectsStoredEventRepository()
event_store = EventStore(stored_event_repo)
self.ps = PersistenceSubscriber(event_store)
event_player = EventPlayer(
event_store=event_store,
id_prefix='Example',
mutate_func=Example.mutate,
snapshot_strategy=EventSourcedSnapshotStrategy(
event_store=event_store))
# Check the method returns None when there are no events.
snapshot = event_player.take_snapshot('wrong')
self.assertIsNone(snapshot)
# Create a new entity.
example = register_new_example(a=123, b=234)
# Take a snapshot with the entity.
snapshot1 = event_player.take_snapshot(example.id)
self.assertIsInstance(snapshot1, Snapshot)
# Take another snapshot with the entity.
snapshot2 = event_player.take_snapshot(example.id)
# - should return the previous snapshot
self.assertIsInstance(snapshot2, Snapshot)
self.assertEqual(snapshot2.at_event_id, snapshot1.at_event_id)
# Generate a domain event.
example.beat_heart()
# Take another snapshot with the entity.
# - should use the previous snapshot and the heartbeat event
snapshot3 = event_player.take_snapshot(example.id)
self.assertNotEqual(snapshot3.at_event_id, snapshot1.at_event_id)
def test_with_snapshots(self):
# Check the EventPlayer's take_snapshot() method.
stored_event_repo = PythonObjectsStoredEventRepository()
event_store = EventStore(stored_event_repo)
self.ps = PersistenceSubscriber(event_store)
event_player = EventPlayer(
event_store=event_store,
id_prefix='Example',
mutate_func=Example.mutate,
snapshot_strategy=EventSourcedSnapshotStrategy(event_store=event_store)
)
# Check the method returns None when there are no events.
snapshot = event_player.take_snapshot('wrong')
self.assertIsNone(snapshot)
# Create a new entity.
example = register_new_example(a=123, b=234)
# Take a snapshot with the entity.
snapshot1 = event_player.take_snapshot(example.id)
self.assertIsInstance(snapshot1, Snapshot)
# Take another snapshot with the entity.
snapshot2 = event_player.take_snapshot(example.id)
# - should return the previous snapshot
self.assertIsInstance(snapshot2, Snapshot)
self.assertEqual(snapshot2.at_event_id, snapshot1.at_event_id)
# Generate a domain event.
example.beat_heart()
# Take another snapshot with the entity.
# - should use the previous snapshot and the heartbeat event
snapshot3 = event_player.take_snapshot(example.id)
self.assertNotEqual(snapshot3.at_event_id, snapshot1.at_event_id)
def register_new_example(self, a, b):
return register_new_example(a=a, b=b)
def register_new_example(self, a, b):
return register_new_example(a=a, b=b)
def test_entity_performance(self):
"""
Reports on the performance of Example entity and repo.
NB: This test doesn't actually check anything, so it isn't really a test.
"""
# Initialise dict of entities.
self.entities = {}
report_name = type(self).__name__[4:]
print("\n\n{} report:\n".format(report_name))
repetitions = 10
# NB: Use range(1, 5) to test whether we can get more than 10000 event from Cassandra.
for i in six.moves.range(0, 5):
# Setup a number of entities, with different lengths of event history.
payload = 3
# payload = str([uuid4().hex for _ in six.moves.range(100000)])
example = register_new_example(a=1, b=payload)
self.entities[i] = example
# Beat a number of times.
start_beating = utc_now()
num_beats = int(floor(10 ** i))
for _ in six.moves.range(num_beats):
example.beat_heart()
time_beating = utc_now() - start_beating
print("Time to beat {} times: {:.2f}s ({:.0f} beats/s, {:.6f}s each)"
"".format(num_beats, time_beating, num_beats / time_beating, time_beating / num_beats))
# Get the last n events from the repo.
def last_n(n):
n = min(n, num_beats + 1)
stored_entity_id = make_stored_entity_id('Example', example.id)
repo = self.app.example_repo.event_player.event_store.stored_event_repo
start_last_n = utc_now()
last_n_stored_events = []
for _ in six.moves.range(repetitions):
last_n_stored_events = repo.get_most_recent_events(stored_entity_id, limit=n)
time_last_n = (utc_now() - start_last_n) / repetitions
num_retrieved_events = len(list(last_n_stored_events))
events_per_second = num_retrieved_events / time_last_n
print(("Time to get last {:>"+str(i+1)+"} events after {} events: {:.6f}s ({:.0f} events/s)"
"").format(n, num_beats + 1, time_last_n, events_per_second))
for j in range(0, i+1):
last_n(10**j)
# Get the entity by replaying all events (which it must since there isn't a snapshot).
start_replay = utc_now()
for _ in six.moves.range(repetitions):
example = self.app.example_repo[example.id]
assert isinstance(example, Example)
heartbeats = example.count_heartbeats()
assert heartbeats == num_beats, (heartbeats, num_beats)
time_replaying = (utc_now() - start_replay) / repetitions
print("Time to replay {} beats: {:.2f}s ({:.0f} beats/s, {:.6f}s each)"
"".format(num_beats, time_replaying, num_beats / time_replaying, time_replaying / num_beats))
# Take snapshot, and beat heart a few more times.
self.app.example_repo.event_player.take_snapshot(example.id, until=uuid1().hex)
extra_beats = 4
for _ in six.moves.range(extra_beats):
example.beat_heart()
num_beats += extra_beats
# Get the entity using snapshot and replaying events since the snapshot.
start_replay = utc_now()
for _ in six.moves.range(repetitions):
example = self.app.example_repo[example.id]
time_replaying = (utc_now() - start_replay) / repetitions
events_per_second = (extra_beats + 1) / time_replaying # +1 for the snapshot event
beats_per_second = num_beats / time_replaying
print("Time to replay snapshot with {} extra beats: {:.6f}s ({:.0f} events/s, {:.0f} beats/s)"
"".format(extra_beats, time_replaying, events_per_second, beats_per_second))
print("")
def test_snapshots(self):
stored_event_repo = PythonObjectsStoredEventRepository()
event_store = EventStore(stored_event_repo)
self.ps = PersistenceSubscriber(event_store)
event_player = EventPlayer(event_store=event_store,
id_prefix='Example',
mutate_func=Example.mutate)
# Create a new entity.
registered_example = register_new_example(a=123, b=234)
# Take a snapshot.
snapshot = take_snapshot(registered_example, uuid1().hex)
# Replay from this snapshot.
after = snapshot.at_event_id
initial_state = entity_from_snapshot(snapshot)
retrieved_example = event_player.replay_events(
registered_example.id, initial_state=initial_state, after=after)
# Check the attributes are correct.
self.assertEqual(retrieved_example.a, 123)
# Remember the time now.
timecheck1 = uuid1().hex
# Change attribute value.
retrieved_example.a = 999
# Check the initial state doesn't move.
self.assertEqual(initial_state.a, 123)
# Remember the time now.
timecheck2 = uuid1().hex
# Change attribute value.
retrieved_example.a = 9999
# Remember the time now.
timecheck3 = uuid1().hex
# Check the event sourced entities are correct.
assert initial_state.a == 123
retrieved_example = event_player.replay_events(registered_example.id)
self.assertEqual(retrieved_example.a, 9999)
# Take another snapshot.
snapshot2 = take_snapshot(retrieved_example, uuid1().hex)
# Check we can replay from this snapshot.
initial_state2 = entity_from_snapshot(snapshot2)
after2 = snapshot2.domain_event_id
retrieved_example = event_player.replay_events(
registered_example.id, initial_state=initial_state2, after=after2)
# Check the attributes are correct.
self.assertEqual(retrieved_example.a, 9999)
# Check we can get historical state at timecheck1.
retrieved_example = event_player.replay_events(registered_example.id,
until=timecheck1)
self.assertEqual(retrieved_example.a, 123)
# Check we can get historical state at timecheck2.
retrieved_example = event_player.replay_events(registered_example.id,
until=timecheck2)
self.assertEqual(retrieved_example.a, 999)
# Check we can get historical state at timecheck3.
retrieved_example = event_player.replay_events(registered_example.id,
until=timecheck3)
self.assertEqual(retrieved_example.a, 9999)
# Similarly, check we can get historical state using a snapshot
retrieved_example = event_player.replay_events(
registered_example.id,
initial_state=initial_state,
after=after,
until=timecheck2)
self.assertEqual(retrieved_example.a, 999)
def test_snapshots(self):
stored_event_repo = PythonObjectsStoredEventRepository()
event_store = EventStore(stored_event_repo)
self.ps = PersistenceSubscriber(event_store)
event_player = EventPlayer(event_store=event_store, id_prefix='Example', mutate_func=Example.mutate)
# Create a new entity.
registered_example = register_new_example(a=123, b=234)
# Take a snapshot.
snapshot = take_snapshot(registered_example, uuid1().hex)
# Replay from this snapshot.
after = snapshot.at_event_id
initial_state = entity_from_snapshot(snapshot)
retrieved_example = event_player.replay_events(registered_example.id, initial_state=initial_state, after=after)
# Check the attributes are correct.
self.assertEqual(retrieved_example.a, 123)
# Remember the time now.
timecheck1 = uuid1().hex
# Change attribute value.
retrieved_example.a = 999
# Check the initial state doesn't move.
self.assertEqual(initial_state.a, 123)
# Remember the time now.
timecheck2 = uuid1().hex
# Change attribute value.
retrieved_example.a = 9999
# Remember the time now.
timecheck3 = uuid1().hex
# Check the event sourced entities are correct.
assert initial_state.a == 123
retrieved_example = event_player.replay_events(registered_example.id)
self.assertEqual(retrieved_example.a, 9999)
# Take another snapshot.
snapshot2 = take_snapshot(retrieved_example, uuid1().hex)
# Check we can replay from this snapshot.
initial_state2 = entity_from_snapshot(snapshot2)
after2 = snapshot2.domain_event_id
retrieved_example = event_player.replay_events(registered_example.id, initial_state=initial_state2, after=after2)
# Check the attributes are correct.
self.assertEqual(retrieved_example.a, 9999)
# Check we can get historical state at timecheck1.
retrieved_example = event_player.replay_events(registered_example.id, until=timecheck1)
self.assertEqual(retrieved_example.a, 123)
# Check we can get historical state at timecheck2.
retrieved_example = event_player.replay_events(registered_example.id, until=timecheck2)
self.assertEqual(retrieved_example.a, 999)
# Check we can get historical state at timecheck3.
retrieved_example = event_player.replay_events(registered_example.id, until=timecheck3)
self.assertEqual(retrieved_example.a, 9999)
# Similarly, check we can get historical state using a snapshot
retrieved_example = event_player.replay_events(registered_example.id, initial_state=initial_state, after=after, until=timecheck2)
self.assertEqual(retrieved_example.a, 999)
def test_entity_lifecycle(self):
# Check the factory creates an instance.
example1 = register_new_example(a=1, b=2)
self.assertIsInstance(example1, Example)
# Check the properties of the Example class.
self.assertEqual(1, example1.a)
self.assertEqual(2, example1.b)
# Check the properties of the EventSourcedEntity class.
self.assertTrue(example1.id)
self.assertEqual(1, example1.version)
self.assertTrue(example1.created_on)
# Check a second instance with the same values is not "equal" to the first.
example2 = register_new_example(a=1, b=2)
self.assertNotEqual(example1, example2)
# Setup the repo.
repo = ExampleRepo(self.event_store)
# Check the example entities can be retrieved from the example repository.
entity1 = repo[example1.id]
self.assertIsInstance(entity1, Example)
self.assertEqual(1, entity1.a)
self.assertEqual(2, entity1.b)
entity2 = repo[example2.id]
self.assertIsInstance(entity2, Example)
self.assertEqual(1, entity2.a)
self.assertEqual(2, entity2.b)
# Check the entity can be updated.
entity1.a = 100
self.assertEqual(100, repo[entity1.id].a)
entity1.b = -200
self.assertEqual(-200, repo[entity1.id].b)
self.assertEqual(0, entity1.count_heartbeats())
entity1.beat_heart()
entity1.beat_heart()
entity1.beat_heart()
self.assertEqual(3, entity1.count_heartbeats())
self.assertEqual(3, repo[entity1.id].count_heartbeats())
# Check the entity can be discarded.
entity1.discard()
# Check the repo now raises a KeyError.
self.assertRaises(RepositoryKeyError, repo.__getitem__, entity1.id)
# Check the entity can't be discarded twice.
self.assertRaises(AssertionError, entity1.discard)
# Should fail to validate event with wrong entity ID.
self.assertRaises(
EntityIDConsistencyError, entity2._validate_originator,
DomainEvent(entity_id=entity2.id + 'wrong', entity_version=0))
# Should fail to validate event with wrong entity version.
self.assertRaises(EntityVersionConsistencyError,
entity2._validate_originator,
DomainEvent(entity_id=entity2.id, entity_version=0))
# Should validate event with correct entity ID and version.
entity2._validate_originator(
DomainEvent(entity_id=entity2.id, entity_version=entity2.version))
# Check an entity can be reregistered with the same ID.
replacement_event = Example.Created(entity_id=entity1.id, a=11, b=12)
# replacement = Example.mutate(event=replacement_event)
publish(event=replacement_event)
# Check the replacement entity can be retrieved from the example repository.
replacement = repo[entity1.id]
assert isinstance(replacement, Example)
self.assertEqual(replacement.a, 11)
self.assertEqual(replacement.b, 12)
def test_entity_lifecycle(self):
# Check the factory creates an instance.
example1 = register_new_example(a=1, b=2)
self.assertIsInstance(example1, Example)
# Check the properties of the Example class.
self.assertEqual(1, example1.a)
self.assertEqual(2, example1.b)
# Check the properties of the EventSourcedEntity class.
self.assertTrue(example1.id)
self.assertEqual(1, example1.version)
self.assertTrue(example1.created_on)
# Check a second instance with the same values is not "equal" to the first.
example2 = register_new_example(a=1, b=2)
self.assertNotEqual(example1, example2)
# Setup the repo.
repo = ExampleRepo(self.event_store)
# Check the example entities can be retrieved from the example repository.
entity1 = repo[example1.id]
self.assertIsInstance(entity1, Example)
self.assertEqual(1, entity1.a)
self.assertEqual(2, entity1.b)
entity2 = repo[example2.id]
self.assertIsInstance(entity2, Example)
self.assertEqual(1, entity2.a)
self.assertEqual(2, entity2.b)
# Check the entity can be updated.
entity1.a = 100
self.assertEqual(100, repo[entity1.id].a)
entity1.b = -200
self.assertEqual(-200, repo[entity1.id].b)
self.assertEqual(0, entity1.count_heartbeats())
entity1.beat_heart()
entity1.beat_heart()
entity1.beat_heart()
self.assertEqual(3, entity1.count_heartbeats())
self.assertEqual(3, repo[entity1.id].count_heartbeats())
# Check the entity can be discarded.
entity1.discard()
# Check the repo now raises a KeyError.
self.assertRaises(RepositoryKeyError, repo.__getitem__, entity1.id)
# Check the entity can't be discarded twice.
self.assertRaises(AssertionError, entity1.discard)
# Should fail to validate event with wrong entity ID.
self.assertRaises(EntityIDConsistencyError,
entity2._validate_originator,
DomainEvent(entity_id=entity2.id+'wrong', entity_version=0)
)
# Should fail to validate event with wrong entity version.
self.assertRaises(EntityVersionConsistencyError,
entity2._validate_originator,
DomainEvent(entity_id=entity2.id, entity_version=0)
)
# Should validate event with correct entity ID and version.
entity2._validate_originator(
DomainEvent(entity_id=entity2.id, entity_version=entity2.version)
)
# Check an entity can be reregistered with the same ID.
replacement_event = Example.Created(entity_id=entity1.id, a=11, b=12)
# replacement = Example.mutate(event=replacement_event)
publish(event=replacement_event)
# Check the replacement entity can be retrieved from the example repository.
replacement = repo[entity1.id]
assert isinstance(replacement, Example)
self.assertEqual(replacement.a, 11)
self.assertEqual(replacement.b, 12)
