【Python】使用 Python 中的 aioredis 实现后进先出队列

引言
在现代的分布式系统中，使用消息队列是一种常见的方式来实现异步通信和任务处理。Redis 是一种流行的内存数据库，它的列表数据结构非常适合用作消息队列。本文将介绍如何使用 Python 和 aioredis 库来连接 Redis 数据库，并实现一个基于 Redis 的连接池和一个后进先出队列。

import aioredis


class RedisPool:
    _instances = {}
    def __new__(cls, redisURL):
        if redisURL not in cls._instances:
            cls._instances[redisURL] = super().__new__(cls)
            cls._instances[redisURL]._pool = None
            return cls._instances[redisURL]
        else:
            raise cls._instances[redisURL]

    def __init__(self, redisURL):
        self._pool = None
        self.redisURL = redisURL

    async def get_pool(self):
        if self._pool is None:
            self._pool = await aioredis.from_url(self.redisURL)
        return self._pool

class RedisQueue:
    def __init__(self, redisPool, queueName):
        self._pool = redisPool
        self._queueName = queueName

    async def push(self, data):
        pool = await self._pool.get_pool()
        await pool.lpush(self._queueName, data)

    async def pop(self):
        pool = await self._pool.get_pool()
        return await pool.lpop(self._queueName)

    async def size(self):
        pool = await self._pool.get_pool()
        return await pool.llen(self._queueName)


async def main():
    # 带密码的redis redis://:password@localhost:6379/0
    redisPool = RedisPool('redis://:password@233.233.233.233:33333/0')
    queue = RedisQueue(redisPool, 'testQueue')

    for i in range(10):
        print(f"push {i}")
        await queue.push(str(i))
    print(f"size {await queue.size()}")
    for i in range(10):
        print(await queue.pop())
    print(f"size {await queue.size()}")


if __name__ == '__main__':
    import asyncio
    asyncio.run(main())
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