init

services/cache.py

@@ -0,0 +1,43 @@
+from __future__ import annotations
+
+from typing import Optional
+
+try:
+    import redis
+except Exception:
+    redis = None
+
+
+class CacheBase:
+    """缓存接口"""
+
+    def get(self, key: str) -> Optional[str]:
+        raise NotImplementedError
+
+    def set(self, key: str, value: str, ttl: int) -> None:
+        raise NotImplementedError
+
+
+class NoopCache(CacheBase):
+    """空实现缓存"""
+
+    def get(self, key: str) -> Optional[str]:
+        return None
+
+    def set(self, key: str, value: str, ttl: int) -> None:
+        return None
+
+
+class RedisCache(CacheBase):
+    """Redis 缓存"""
+
+    def __init__(self, url: str, db: int = 0):
+        if redis is None:
+            raise ImportError("未安装 redis 依赖")
+        self._client = redis.Redis.from_url(url, db=db, decode_responses=True)
+
+    def get(self, key: str) -> Optional[str]:
+        return self._client.get(key)
+
+    def set(self, key: str, value: str, ttl: int) -> None:
+        self._client.set(key, value, ex=ttl)