def __init__(self, *args, **kwargs):
super().__init__(*args, **kwargs)
self.compare_and_update_script = CompareAndUpdateScript(self.redis)
class SiteStatsDaoRedis(SiteStatsDaoBase, RedisDaoBase):
"""Persists and queries SiteStats in Redis."""
def __init__(self, *args, **kwargs):
super().__init__(*args, **kwargs)
self.compare_and_update_script = CompareAndUpdateScript(self.redis)
def find_by_id(self,
site_id: int,
day: datetime.datetime = None,
**kwargs) -> SiteStats:
if day is None:
day = datetime.datetime.now()
key = self.key_schema.site_stats_key(site_id, day)
fields = self.redis.hgetall(key)
if not fields:
raise SiteStatsNotFound()
return SiteStatsSchema().load(fields)
def _update_basic(self, key: str, reading: MeterReading) -> None:
reporting_time = datetime.datetime.utcnow().isoformat()
self.redis.hset(key, SiteStats.LAST_REPORTING_TIME, reporting_time)
self.redis.hincrby(key, SiteStats.COUNT, 1)
self.redis.expire(key, WEEK_SECONDS)
max_wh = self.redis.hget(key, SiteStats.MAX_WH)
if not max_wh or reading.wh_generated > float(max_wh):
self.redis.hset(key, SiteStats.MAX_WH, reading.wh_generated)
min_wh = self.redis.hget(key, SiteStats.MIN_WH)
if not min_wh or reading.wh_generated < float(min_wh):
self.redis.hset(key, SiteStats.MIN_WH, reading.wh_generated)
max_capacity = self.redis.hget(key, SiteStats.MAX_CAPACITY)
if not max_capacity or reading.current_capacity > float(max_capacity):
self.redis.hset(key, SiteStats.MAX_CAPACITY, reading.wh_generated)
def _update_optimized(self,
key: str,
meter_reading: MeterReading,
pipeline: redis.client.Pipeline = None) -> None:
execute = False
if pipeline is None:
pipeline = self.redis.pipeline()
execute = True
# START Challenge #3
reporting_time = datetime.datetime.utcnow().isoformat()
pipeline.hset(key, SiteStats.LAST_REPORTING_TIME, reporting_time)
pipeline.hincrby(key, SiteStats.COUNT, 1)
pipeline.expire(key, WEEK_SECONDS)
self.compare_and_update_script.update_if_greater(
pipeline, key, SiteStats.MAX_WH, meter_reading.wh_generated)
self.compare_and_update_script.update_if_less(
pipeline, key, SiteStats.MIN_WH, meter_reading.wh_generated)
self.compare_and_update_script.update_if_greater(
pipeline, key, SiteStats.MAX_CAPACITY,
meter_reading.current_capacity)
# END Challenge #3
if execute:
pipeline.execute()
def update(self, meter_reading: MeterReading, **kwargs) -> None:
key = self.key_schema.site_stats_key(meter_reading.site_id,
meter_reading.timestamp)
pipeline = kwargs.get('pipeline')
self._update_optimized(key, meter_reading, pipeline)