40 lines
1.1 KiB
Python
40 lines
1.1 KiB
Python
|
import redis
|
||
|
|
|
||
|
|
redis_cycler_db = redis.Redis(host='localhost', port=6379, db=9)
|
||
|
|
|
||
|
|
|
||
|
|
def redis_cycle(list_name):
|
||
|
|
"""
|
||
|
|
Emulates itertools.cycle() but returns the complete shuffled list.
|
||
|
|
:param list_name:
|
||
|
|
:return:
|
||
|
|
"""
|
||
|
|
pipeline = redis_cycler_db.pipeline()
|
||
|
|
pipeline.lpop(list_name)
|
||
|
|
to_move = pipeline.execute()[0]
|
||
|
|
if not to_move:
|
||
|
|
return []
|
||
|
|
pipeline.rpush(list_name, to_move)
|
||
|
|
pipeline.lrange(list_name, 0, -1)
|
||
|
|
results = pipeline.execute()
|
||
|
|
new_list = results[-1]
|
||
|
|
return [x.decode('utf-8') for x in new_list]
|
||
|
|
|
||
|
|
|
||
|
|
def add_backend_cycler(list_name: str, new_elements: list):
|
||
|
|
existing_elements = [i.decode('utf-8') for i in redis_cycler_db.lrange(list_name, 0, -1)]
|
||
|
|
existing_set = set(existing_elements)
|
||
|
|
|
||
|
|
with redis_cycler_db.pipeline() as pipe:
|
||
|
|
# Add elements
|
||
|
|
for element in new_elements:
|
||
|
|
if element not in existing_set:
|
||
|
|
pipe.rpush(list_name, element)
|
||
|
|
|
||
|
|
# Remove elements
|
||
|
|
for element in existing_set:
|
||
|
|
if element not in new_elements:
|
||
|
|
pipe.lrem(list_name, 0, element)
|
||
|
|
|
||
|
|
pipe.execute()
|