129 lines
3.6 KiB
Python
129 lines
3.6 KiB
Python
|
"""
|
||
|
|
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
|
||
|
|
|