def get_flag_by_field(
name: str,
value: Union[str, int],
current_round: int,
) -> Optional[models.Flag]:
"""
Get flag by generic field.
:param name: field name to ask cache for
:param value: value of the field "field_name" to filter on
:param current_round: current round
:returns: Flag model instance with flag.field_name == field_value or None
"""
cached_key = CacheKeys.flags_cached()
with utils.redis_pipeline(transaction=True) as pipe:
cached, = pipe.exists(cached_key).execute()
if not cached:
cache_helper(
pipeline=pipe,
cache_key=cached_key,
cache_func=caching.cache_last_flags,
cache_args=(current_round, pipe),
)
flag_json, = pipe.get(CacheKeys.flag_by_field(name, value)).execute()
if not flag_json:
return None
flag = models.Flag.from_json(flag_json)
return flag
def cache_last_flags(current_round: int, pipe: Pipeline) -> None:
"""
Cache all generated flags from last "flag_lifetime" rounds.
Just adds commands to pipeline stack, don't forget to execute afterwards.
:param current_round: current round
:param pipe: redis connection to add command to
"""
game_config = game.get_current_game_config()
expires = game_config.flag_lifetime * game_config.round_time * 2
with utils.db_cursor(dict_cursor=True) as (_, curs):
curs.execute(
_SELECT_ALL_LAST_FLAGS_QUERY,
{'round': current_round - game_config.flag_lifetime},
)
flags = curs.fetchall()
flag_models = list(models.Flag.from_dict(data) for data in flags)
pipe.set(CacheKeys.flags_cached(), 1)
for flag in flag_models:
pipe.set(CacheKeys.flag_by_id(flag.id), flag.to_json(), ex=expires)
pipe.set(CacheKeys.flag_by_str(flag.flag), flag.to_json(), ex=expires)
