import os
from typing import Optional
from uuid import uuid4
from redis import Redis, StrictRedis
from eventsourcing.infrastructure.integersequencegenerators.base import (
AbstractIntegerSequenceGenerator,
)
[docs]class RedisIncr(AbstractIntegerSequenceGenerator):
"""
Generates a sequence of integers, using Redis' INCR command.
Maximum number is 2**63, or 9223372036854775807, the maximum
value of a 64 bit signed integer.
"""
[docs] def __init__(self, redis: Optional[Redis] = None, key: Optional[str] = None):
redis_host = os.getenv("REDIS_HOST", "localhost")
self.redis = redis or StrictRedis(host=redis_host)
self.key = key or "integer-sequence-generator-{}".format(uuid4())
[docs] def __next__(self) -> int:
return self.redis.incr(self.key) - 1