59 lines
2.3 KiB
Python
59 lines
2.3 KiB
Python
"""NL2SQL 查询配额、并发和频率限制。"""
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from __future__ import annotations
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import time
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class QueryLimiter:
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"""基于 Redis 计数器的请求限制器，Redis 故障时允许降级放行。"""
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def __init__(self, redis, *, rate_window_seconds: int = 60):
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self.redis = redis
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self.rate_window_seconds = rate_window_seconds
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async def acquire(
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self,
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user_id: int,
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*,
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daily_quota: int = 0,
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max_concurrent: int = 1,
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rate_limit: int = 0,
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) -> bool:
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"""检查并占用一次配额、并发和频率额度，0 表示不限制。"""
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try:
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if daily_quota:
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daily_key = f"nl2sql:daily:{user_id}:{time.strftime('%Y%m%d')}"
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daily_count = await self.redis.incr(daily_key)
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await self.redis.expire(daily_key, 86400)
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if daily_count > daily_quota:
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await self.redis.decr(daily_key)
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return False
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concurrent_key = f"nl2sql:concurrent:{user_id}"
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concurrent_count = await self.redis.incr(concurrent_key)
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await self.redis.expire(concurrent_key, 3600)
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if max_concurrent and concurrent_count > max_concurrent:
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await self.redis.decr(concurrent_key)
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if daily_quota:
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await self.redis.decr(daily_key)
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return False
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if rate_limit:
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rate_key = f"nl2sql:rate:{user_id}:{int(time.time()) // self.rate_window_seconds}"
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rate_count = await self.redis.incr(rate_key)
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await self.redis.expire(rate_key, self.rate_window_seconds + 1)
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if rate_count > rate_limit:
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await self.redis.decr(rate_key)
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await self.redis.decr(concurrent_key)
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if daily_quota:
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await self.redis.decr(daily_key)
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return False
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return True
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except Exception: # noqa: BLE001 Redis 故障时降级为不限制
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return True
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async def release(self, user_id: int) -> None:
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"""释放一次并发额度，失败时静默降级。"""
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try:
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await self.redis.decr(f"nl2sql:concurrent:{user_id}")
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except Exception: # noqa: BLE001 Redis 故障不能影响查询结果
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return
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