def _relations_sync(moved_sensor_ids: typing.List[int]):
logger = get_celery_logger()
trie: Trie[Zipcode] = Trie()
for zipcode in Zipcode.query.all():
trie.insert(zipcode.geohash, zipcode)
new_relations = []
# Delete the old relations before rebuilding them
deleted_relations_count = SensorZipcodeRelation.query.filter(
SensorZipcodeRelation.sensor_id.in_(moved_sensor_ids)).delete(
synchronize_session=False)
logger.info("Deleting %s relations", deleted_relations_count)
sensors = Sensor.query.filter(Sensor.id.in_(moved_sensor_ids)).all()
for sensor in sensors:
gh = sensor.geohash
latitude = sensor.latitude
longitude = sensor.longitude
done = False
zipcode_ids: typing.Set[int] = set()
# TODO: Use Postgres' native geolocation extension.
while gh and not done:
zipcodes = [
zipcode for zipcode in trie.get(gh)
if zipcode.id not in zipcode_ids
]
for zipcode_id, distance in sorted(
[(
z.id,
haversine_distance(longitude, latitude, z.longitude,
z.latitude),
) for z in zipcodes],
key=lambda t: t[1],
):
if distance >= 25:
done = True
break
if len(zipcode_ids) >= 25:
done = True
break
zipcode_ids.add(zipcode_id)
data = {
"zipcode_id": zipcode_id,
"sensor_id": sensor.id,
"distance": distance,
}
new_relations.append(SensorZipcodeRelation(**data))
gh = gh[:-1]
if new_relations:
logger.info("Creating %s relations", len(new_relations))
for objs in chunk_list(new_relations):
db.session.bulk_save_objects(objs)
db.session.commit()
def distance(self, other: "Zipcode") -> float:
"""Distance between this zip and the given zip."""
if other.id in self._distance_cache:
return self._distance_cache[other.id]
if self.id in other._distance_cache:
return other._distance_cache[self.id]
self._distance_cache[other.id] = haversine_distance(
other.longitude,
other.latitude,
self.longitude,
self.latitude,
)
return self._distance_cache[other.id]
def _is_in_range(lat: float, lon: float):
return haversine_distance(lon, lat, COORDINATES[1],
COORDINATES[0]) < RADIUS