|
|
import logging
|
|
|
import time
|
|
|
|
|
|
from sqlalchemy import text
|
|
|
|
|
|
logger = logging.getLogger(__name__)
|
|
|
|
|
|
|
|
|
class StorageManager:
|
|
|
"""存储管理器骨架，封装 Redis / MySQL 可用性检测与三级降级状态。"""
|
|
|
|
|
|
def __init__(self, redis_client=None, mysql_engine=None, check_interval=30):
|
|
|
self.redis_client = redis_client
|
|
|
self.mysql_engine = mysql_engine
|
|
|
self.check_interval = check_interval
|
|
|
|
|
|
self.redis_available = False
|
|
|
self.mysql_available = False
|
|
|
self.last_redis_check = 0
|
|
|
self.last_mysql_check = 0
|
|
|
|
|
|
def check_redis(self):
|
|
|
"""惰性检测 Redis 可用性，30 秒间隔内返回缓存结果。"""
|
|
|
now = time.time()
|
|
|
if now - self.last_redis_check < self.check_interval:
|
|
|
return self.redis_available
|
|
|
|
|
|
if self.redis_client is None:
|
|
|
self.redis_available = False
|
|
|
else:
|
|
|
try:
|
|
|
self.redis_client.ping()
|
|
|
self.redis_available = True
|
|
|
except Exception as e:
|
|
|
self.redis_available = False
|
|
|
|
|
|
self.last_redis_check = now
|
|
|
return self.redis_available
|
|
|
|
|
|
def check_mysql(self):
|
|
|
"""惰性检测 MySQL 可用性，30 秒间隔内返回缓存结果。"""
|
|
|
now = time.time()
|
|
|
if now - self.last_mysql_check < self.check_interval:
|
|
|
return self.mysql_available
|
|
|
|
|
|
if self.mysql_engine is None:
|
|
|
self.mysql_available = False
|
|
|
else:
|
|
|
try:
|
|
|
with self.mysql_engine.connect() as conn:
|
|
|
conn.execute(text("SELECT 1"))
|
|
|
self.mysql_available = True
|
|
|
except Exception as e:
|
|
|
self.mysql_available = False
|
|
|
|
|
|
self.last_mysql_check = now
|
|
|
return self.mysql_available
|
|
|
|
|
|
def is_available(self):
|
|
|
"""判断 Redis 或 MySQL 至少一个可用。"""
|
|
|
return self.check_redis() or self.check_mysql()
|
|
|
|
|
|
def initialize(self):
|
|
|
"""启动时调用，检测各后端可用性并输出日志。"""
|
|
|
redis_ok = self.check_redis()
|
|
|
mysql_ok = self.check_mysql()
|
|
|
|
|
|
if redis_ok:
|
|
|
logger.info("Redis 可用")
|
|
|
else:
|
|
|
logger.warning("Redis 不可用")
|
|
|
|
|
|
if mysql_ok:
|
|
|
logger.info("MySQL 可用")
|
|
|
else:
|
|
|
logger.warning("MySQL 不可用")
|
|
|
|
|
|
|
|
|
_storage_manager = None
|
|
|
|
|
|
|
|
|
def get_storage_manager():
|
|
|
"""获取全局 StorageManager 单例。"""
|
|
|
global _storage_manager
|
|
|
if _storage_manager is None:
|
|
|
_storage_manager = StorageManager()
|
|
|
return _storage_manager
|
