redis checksum

connection.py

# We use the redis-py library https://github.com/andymccurdy/redis-py
import redis

# This library is taken verbatim from https://gist.github.com/larsimmisch/9915766
from libs.crc64 import crc64

redis_client = redis.from_url(REDIS_URL, charset="utf-8", decode_responses=True)

def store(l):
    values = []
    for v in l:
        cs = crc64(v)
        values.append('{}:{}'.format(cs, v))
    pipe = managers.redis.pipeline()
    pipe.rpush(key, *values)
    pipe.expire(key, TTL)
    pipe.execute()
    
    
def fetch(key):
    for value in managers.redis.lrange(key, 0, -1):
        idx = value.index(':')
        cs, v = value[:idx], value[idx+1:]
        cs = int(cs)
        if crc64(v) != cs:
            raise Exception('invalid checksum for buffer storage data cs={} value={}'.format(cs, v))