def test_value_accumulator_can_be_created_from_value():
reference = ValueAccumulator()
reference.add(4.2)
acc = ValueAccumulator(4.2)
assert acc == reference
def test_value_accumulator_can_be_created_from_list():
reference = ValueAccumulator()
reference.add(4.2)
reference.add(1.3)
acc = ValueAccumulator([4.2, 1.3])
assert acc == reference
def test_value_accumulator_can_be_stored_as_bytes():
values = [4.2, -1.3, 10.8]
acc = ValueAccumulator(values)
data = acc.to_bytes()
assert isinstance(data, bytes)
restored_acc = ValueAccumulator.from_bytes(data)
assert acc == restored_acc
def test_value_accumulator_can_add_value():
value = 4.2
acc = ValueAccumulator()
acc.add(value)
assert acc.count == 1
assert acc.sum == value
assert acc.avg == value
assert acc.stddev is None
assert acc.min == value
assert acc.max == value
assert acc.lo == value
assert acc.hi == value
def test_value_accumulator_can_add_several_values():
values = [4.2, -1.3, 10.8]
acc = ValueAccumulator()
for value in values:
acc.add(value)
assert acc.count == len(values)
assert acc.sum == sum(values)
assert acc.avg == statistics.mean(values)
assert acc.stddev == statistics.stdev(values)
assert acc.min == min(values)
assert acc.max == max(values)
assert acc.min < acc.lo < acc.avg
assert acc.avg < acc.hi < acc.max
assert math.isclose(acc.hi - acc.lo, acc.stddev)
def test_value_accumulator_handles_same_values():
value = 4.2
count = 5
acc = ValueAccumulator()
for _ in range(count):
acc.add(value)
assert acc.count == count
assert acc.sum == value * count
assert acc.avg == value
assert acc.stddev == 0
assert acc.min == value
assert acc.max == value
assert acc.lo == value
assert acc.hi == value
def test_value_accumulator_dont_return_anything_when_created():
acc = ValueAccumulator()
assert acc.count == 0
assert acc.sum == 0
assert acc.avg is None
assert acc.stddev is None
assert acc.min is None
assert acc.max is None
assert acc.lo is None
assert acc.hi is None
def generate_events(num: int, min_ts=None) -> List[MetricsEvent]:
ts = gen_next_timestamp(min_ts)
result = []
for _ in range(num):
ts = gen_next_timestamp(ts)
name = gen_metrics_name()
if random() > 0.5:
value = gauss(0.0, 100.0)
else:
value = ValueAccumulator([gauss(0.0, 100.0) for _ in range(randint(2, 5))])
result += [MetricsEvent(ts, name, value)]
return result
def decode(key: bytes, value: bytes) -> Optional[MetricsEvent]:
key = int.from_bytes(key, byteorder='big', signed=False)
ts = datetime.utcfromtimestamp((key >> KvStoreMetricsFormat.seq_bits) / 1000000.0)
name = int.from_bytes(value[:32], byteorder='big', signed=False)
if name not in MetricsName.__members__.values():
return None
name = MetricsName(name)
data = value[32:]
if len(data) == 8:
value = struct.unpack('d', data)[0]
else:
value = ValueAccumulator.from_bytes(data)
return MetricsEvent(ts, name, value)
def decode(key: bytes, value: bytes) -> Optional[MetricsEvent]:
key = int.from_bytes(key, byteorder='big', signed=False)
ts = datetime.utcfromtimestamp((key >> KvStoreMetricsFormat.seq_bits) / 1000000.0)
name = int.from_bytes(value[:32], byteorder='big', signed=False)
if name not in MetricsName.__members__.values():
return None
name = MetricsName(name)
data = value[32:]
if len(data) == 8:
value = struct.unpack('d', data)[0]
else:
value = ValueAccumulator.from_bytes(data)
return MetricsEvent(ts, name, value)
def test_value_accumulator_with_one_value_is_stored_as_single_float64():
acc = ValueAccumulator()
acc.add(4.2)
data = acc.to_bytes()
assert struct.unpack('d', data)[0] == 4.2
restored_acc = ValueAccumulator.from_bytes(data)
assert acc == restored_acc
def test_value_accumulator_can_merge():
values = [4.2, -1.3, 10.8]
acc = ValueAccumulator(values)
other_values = [3.7, 7.6, -8.5]
other_acc = ValueAccumulator(other_values)
all_values = values + other_values
all_acc = ValueAccumulator(all_values)
acc.merge(other_acc)
assert acc == all_acc
decoded_event = KvStoreMetricsFormat.decode(k, v)
assert event == decoded_event
def test_kv_store_encode_generate_different_keys_for_different_seq_no():
event = MetricsEvent(gen_next_timestamp(), gen_metrics_name(), 4.2)
k1, v1 = KvStoreMetricsFormat.encode(event, 1)
k2, v2 = KvStoreMetricsFormat.encode(event, 2)
assert k1 != k2
assert v1 == v2
@pytest.mark.parametrize("value", [4.2, ValueAccumulator([42, -7, 0])])
def test_kv_store_metrics_collector_stores_properly_encoded_data(
storage: KeyValueStorage, value):
ts = MockTimestamp(gen_next_timestamp())
metrics = KvStoreMetricsCollector(storage, ts)
assert len([(k, v) for k, v in storage.iterator()]) == 0
id = gen_metrics_name()
event = MetricsEvent(ts.value, id, value)
encoded_key, encoded_value = KvStoreMetricsFormat.encode(event)
metrics.store_event(id, value)
stored_events = [(k, v) for k, v in storage.iterator()]
assert len(stored_events) == 1
assert stored_events[0][0] == encoded_key
def test_value_accumulator_eq_has_value_semantics():
a = ValueAccumulator()
b = ValueAccumulator()
assert a == b
a.add(1.0)
assert a != b
b.add(1.0)
assert a == b
a.add(2.0)
b.add(3.0)
assert a != b