creat

Signed-off-by: TIANHE <TIANHE@GMAIL.COM>
2025-12-29 03:06:49 +08:00
commit f43312a858
292 changed files with 103739 additions and 0 deletions
@@ -0,0 +1,128 @@
+"""
+Cache utilities.
+Local-first behavior: use in-memory cache by default.
+Redis is only used when explicitly enabled via environment variables.
+"""
+import time
+import threading
+from typing import Optional, Any
+import json
+
+from app.utils.logger import get_logger
+from app.config import CacheConfig
+
+logger = get_logger(__name__)
+
+
+class MemoryCache:
+    """内存缓存（Redis 不可用时的备选方案）"""
+    
+    def __init__(self):
+        self._cache = {}
+        self._lock = threading.Lock()
+    
+    def get(self, key: str) -> Optional[str]:
+        with self._lock:
+            if key in self._cache:
+                data, expiry = self._cache[key]
+                if expiry > time.time():
+                    return data
+                else:
+                    del self._cache[key]
+            return None
+    
+    def setex(self, key: str, ttl: int, value: str):
+        with self._lock:
+            expiry = time.time() + ttl
+            self._cache[key] = (value, expiry)
+    
+    def delete(self, key: str):
+        with self._lock:
+            if key in self._cache:
+                del self._cache[key]
+    
+    def clear(self):
+        with self._lock:
+            self._cache.clear()
+
+
+class CacheManager:
+    """缓存管理器"""
+    
+    _instance = None
+    _lock = threading.Lock()
+    
+    def __new__(cls):
+        if cls._instance is None:
+            with cls._lock:
+                if cls._instance is None:
+                    cls._instance = super().__new__(cls)
+                    cls._instance._initialized = False
+        return cls._instance
+    
+    def __init__(self):
+        if self._initialized:
+            return
+            
+        self._initialized = True
+        self._client = None
+        self._use_redis = False
+
+        # Local-first: do NOT touch Redis unless explicitly enabled.
+        if not CacheConfig.ENABLED:
+            self._client = MemoryCache()
+            self._use_redis = False
+            return
+
+        # Try Redis only when enabled.
+        try:
+            import redis
+            from app.config import RedisConfig
+
+            self._client = redis.Redis(
+                host=RedisConfig.HOST,
+                port=RedisConfig.PORT,
+                db=RedisConfig.DB,
+                password=RedisConfig.PASSWORD,
+                decode_responses=True,
+                socket_connect_timeout=RedisConfig.CONNECT_TIMEOUT,
+                socket_timeout=RedisConfig.SOCKET_TIMEOUT
+            )
+            self._client.ping()
+            self._use_redis = True
+            logger.info("Redis cache connected")
+        except Exception as e:
+            # Fall back silently (keep startup logs clean in local mode).
+            logger.info(f"Redis is enabled but unavailable; using in-memory cache instead: {e}")
+            self._client = MemoryCache()
+            self._use_redis = False
+    
+    def get(self, key: str) -> Optional[Any]:
+        """获取缓存"""
+        try:
+            data = self._client.get(key)
+            if data:
+                return json.loads(data)
+            return None
+        except Exception as e:
+            logger.error(f"Cache read failed: {e}")
+            return None
+    
+    def set(self, key: str, value: Any, ttl: int = 300):
+        """设置缓存"""
+        try:
+            self._client.setex(key, ttl, json.dumps(value))
+        except Exception as e:
+            logger.error(f"Cache write failed: {e}")
+    
+    def delete(self, key: str):
+        """删除缓存"""
+        try:
+            self._client.delete(key)
+        except Exception as e:
+            logger.error(f"Cache delete failed: {e}")
+    
+    @property
+    def is_redis(self) -> bool:
+        return self._use_redis
+