def test_create_data_appends_to_existing_data(self):
"""Tests that existing data is incremented instead of replaced."""
# Create 1 sample with the value 1.
option = gendata.DataOptions(datetime.datetime(2018, 1, 1),
datetime.datetime(2018, 1, 1, 0, 0, 1), 1,
'New Topic', 1, 1, 0, 0, 1, 0)
expected = {option.start: model.Datum(option.start, 1, '2.0')}
actual = {option.start: model.Datum(option.start, 1, '1.0')}
gendata.create_data(actual, option)
self.assertEqual(len(expected), len(actual))
self.assertEqual(expected[option.start].value_string,
actual[option.start].value_string)
def test_encode_datum(self): """Encodes a Datum object and ensures it has the correct representation.""" ts = datetime.datetime(2018, 1, 1) datum = model.Datum(ts, 18, 'value') actual = json.loads(json.dumps(datum, cls=codec.DatumEncoder)) expected = [ts.isoformat(), 18, 'value'] self.assertEqual(expected, actual)
def test_write_to_db(self):
"""Test that topics and data can be written to the DB."""
# Create one topic and one datum to be created.
ts = datetime.datetime.now()
self.write_to_db([], [model.Topic(1, 'Topic')],
[model.Datum(ts, 1, '1.0')])
# Verify the items were written.
session = sqlalchemy.orm.Session(bind=self.engine,
expire_on_commit=False)
actual_topics = session.query(model.Topic).all()
actual_data = session.query(model.Datum).all()
self.assertEqual(1, len(actual_topics))
self.assertEqual(1, len(actual_data))
topic = actual_topics[0]
self.assertEqual(1, topic.topic_id)
self.assertEqual('Topic', topic.topic_name)
datum = actual_data[0]
self.assertEqual(ts, datum.ts)
self.assertEqual(1, datum.topic_id)
self.assertEqual('1.0', datum.value_string)
session.close()
def test_latest_data_timestamp(self):
"""Tests that the most recent known timestamp in the DB is returned."""
# Insert two data objects.
first = model.Datum(
datetime.datetime(2018, 1, 1), 18, 'first value string')
second = model.Datum(
datetime.datetime(2018, 1, 2), 18, 'second value string')
session = sqlalchemy.orm.Session(bind=self.engine)
session.add(first)
session.add(second)
session.commit()
# Query database and validate results.
dt = json.loads(self.server.get_latest_data_timestamp())
self.assertNotEqual(first.ts, second.ts)
self.assertNotEqual(dt, first.ts.isoformat())
self.assertEqual(dt, second.ts.isoformat())
session.close()
def create_datum(options, ts):
"""Creates a datum object for the given timestamp and topic.
Args:
options: The configuration options for the current data generation run.
ts: The datum timestamp.
Returns:
A populated datum object, ready for insertion.
"""
# value = offset + A_cos * cos(omega * t) + A_sin * sin(omega * t) + fuzz factor
omega = 2 * math.pi / options.period
seconds = (ts - options.start).total_seconds()
fuzz = random.uniform(-options.spread, options.spread)
x = omega * seconds
value = (options.amplitude_offset + options.amplitude_cos * math.cos(x) +
options.amplitude_sin * math.sin(x) + fuzz)
datum = model.Datum(ts, options.topic_id, str(value))
return datum