107 lines
3.5 KiB
Python
107 lines
3.5 KiB
Python
"""Redis 单例网关（B7 lifespan 管理连接）：预警广播 publish + L3 缓存失效 DEL。
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惰性连接（首次 publish/DEL 才建）；连接/执行失败一律降级日志，不阻塞业务
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（DB 为权威，PRD FR-4 通知语义）。测试注入 fake：monkeypatch 本模块
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`_gateway`，实现 publish(channel, payload) / delete(*keys) 即可。
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"""
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from __future__ import annotations
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import json
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import logging
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from typing import Any
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from app.config.settings import settings
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logger = logging.getLogger(__name__)
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class RedisGateway:
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def __init__(self, url: str | None = None) -> None:
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self._url = url or settings.redis_url
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self._client: Any = None
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def _ensure(self) -> Any:
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if self._client is None:
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import redis
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self._client = redis.Redis.from_url(self._url, decode_responses=True)
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return self._client
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def publish(self, channel: str, payload: dict[str, Any]) -> None:
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self._ensure().publish(channel, json.dumps(payload, ensure_ascii=False))
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def delete(self, *keys: str) -> None:
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self._ensure().delete(*keys)
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def exists(self, key: str) -> bool:
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return bool(self._ensure().exists(key))
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def set_ex(self, key: str, value: str, ttl_seconds: int) -> None:
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self._ensure().setex(key, ttl_seconds, value)
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# ---- 输入防护限流（T-03 · ratelimit:{agent}:{actor} 固定窗口）----
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def incr(self, key: str) -> int:
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"""原子自增并返回新值（INCR）；调用方负责首命中时补 EXPIRE。"""
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return int(self._ensure().incr(key))
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# ---- 会话窗口（T-06 · sess:{agent}:{id}:msgs List）----
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def rpush(self, key: str, *values: str) -> None:
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self._ensure().rpush(key, *values)
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def lrange(self, key: str, start: int, end: int) -> list[str]:
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return self._ensure().lrange(key, start, end)
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def ltrim(self, key: str, start: int, end: int) -> None:
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self._ensure().ltrim(key, start, end)
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def expire(self, key: str, ttl_seconds: int) -> None:
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self._ensure().expire(key, ttl_seconds)
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_gateway: RedisGateway | Any | None = None
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def set_gateway(gateway: RedisGateway | Any | None) -> None:
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"""单例注入点（B7 lifespan 注册；测试注入 fake）。"""
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global _gateway
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_gateway = gateway
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def get_gateway() -> RedisGateway:
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"""取网关单例；未注册时惰性创建（脚本直调场景）。"""
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global _gateway
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if _gateway is None:
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_gateway = RedisGateway()
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return _gateway
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def publish(channel: str, payload: dict[str, Any]) -> None:
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"""广播；失败降级（不阻塞预警落库）。"""
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try:
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get_gateway().publish(channel, payload)
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except Exception:
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logger.exception("publish %s failed", channel)
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def cache_delete(*keys: str) -> None:
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"""写侧缓存失效（PRD §5.1：MySQL 更新时 DEL）；失败降级（TTL 兜底过期）。"""
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try:
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get_gateway().delete(*keys)
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except Exception:
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logger.warning("cache DEL failed (degrade to TTL): %s", keys, exc_info=True)
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def key_exists(key: str) -> bool:
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"""存在性检查（T-01 jti 吊销黑名单）；失败 fail-open 返回 False。
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日志不打 key 全文（jti 吊销 key 含完整 jti，手册 §11 只打前 8 位口径）。
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"""
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try:
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return get_gateway().exists(key)
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except Exception:
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logger.warning("redis EXISTS failed (fail-open), key prefix=%s", key.split(":")[:2], exc_info=True)
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return False
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