引入Redis

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雅诺狐
2025-12-08 17:42:57 +08:00
parent f9b193c86d
commit da27c865d0
8 changed files with 1109 additions and 82 deletions

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"""Redis 缓存后端实现
基于 redis-py 的异步 Redis 缓存实现,支持:
- 异步连接池
- 自动序列化/反序列化
- TTL 过期管理
- 模式删除
- 批量操作
- 统计信息
"""
import asyncio
import json
import pickle
from typing import Any
from src.common.database.optimization.cache_backend import CacheBackend, CacheStats
from src.common.logger import get_logger
logger = get_logger("redis_cache")
import redis.asyncio as aioredis
class RedisCache(CacheBackend):
"""Redis 缓存后端
特性:
- 分布式缓存:支持多实例共享
- 自动序列化:支持 JSON 和 Pickle
- TTL 管理Redis 原生过期机制
- 模式删除:支持通配符删除
- 连接池:高效连接复用
"""
def __init__(
self,
host: str = "localhost",
port: int = 6379,
password: str | None = None,
db: int = 0,
key_prefix: str = "mofox:",
default_ttl: int = 600,
pool_size: int = 10,
socket_timeout: float = 5.0,
ssl: bool = False,
serializer: str = "json", # "json" 或 "pickle"
):
"""初始化 Redis 缓存
Args:
host: Redis 服务器地址
port: Redis 服务器端口
password: Redis 密码(可选)
db: Redis 数据库编号
key_prefix: 缓存键前缀
default_ttl: 默认过期时间(秒)
pool_size: 连接池大小
socket_timeout: socket 超时时间(秒)
ssl: 是否启用 SSL
serializer: 序列化方式json 或 pickle
"""
self.host = host
self.port = port
self.password = password if password else None
self.db = db
self.key_prefix = key_prefix
self.default_ttl = default_ttl
self.pool_size = pool_size
self.socket_timeout = socket_timeout
self.ssl = ssl
self.serializer = serializer
# 连接池和客户端(延迟初始化)
self._pool: Any = None
self._client: Any = None
self._lock = asyncio.Lock()
self._is_closing = False
# 统计信息
self._stats = CacheStats()
self._stats_lock = asyncio.Lock()
logger.info(
f"Redis 缓存初始化: {host}:{port}/{db}, "
f"前缀={key_prefix}, TTL={default_ttl}s, "
f"序列化={serializer}"
)
async def _ensure_connection(self) -> Any:
"""确保 Redis 连接已建立"""
if self._client is not None:
return self._client
async with self._lock:
if self._client is not None:
return self._client
try:
# 创建连接池 (使用 aioredis 模块确保类型安全)
self._pool = aioredis.ConnectionPool(
host=self.host,
port=self.port,
password=self.password,
db=self.db,
max_connections=self.pool_size,
socket_timeout=self.socket_timeout,
socket_connect_timeout=self.socket_timeout,
decode_responses=False, # 我们自己处理序列化
ssl=self.ssl,
)
# 创建客户端
self._client = aioredis.Redis(connection_pool=self._pool)
# 测试连接
await self._client.ping()
logger.info(f"Redis 连接成功: {self.host}:{self.port}/{self.db}")
return self._client
except Exception as e:
logger.error(f"Redis 连接失败: {e}")
self._client = None
self._pool = None
raise
def _make_key(self, key: str) -> str:
"""生成带前缀的完整键名"""
return f"{self.key_prefix}{key}"
def _serialize(self, value: Any) -> bytes:
"""序列化值"""
if self.serializer == "json":
try:
return json.dumps(value, ensure_ascii=False, default=str).encode("utf-8")
except (TypeError, ValueError):
# JSON 序列化失败,回退到 pickle
return pickle.dumps(value, protocol=pickle.HIGHEST_PROTOCOL)
else:
return pickle.dumps(value, protocol=pickle.HIGHEST_PROTOCOL)
def _deserialize(self, data: bytes) -> Any:
"""反序列化值"""
if self.serializer == "json":
try:
return json.loads(data.decode("utf-8"))
except (json.JSONDecodeError, UnicodeDecodeError):
# JSON 反序列化失败,尝试 pickle
try:
return pickle.loads(data)
except Exception:
return None
else:
try:
return pickle.loads(data)
except Exception:
return None
async def get(self, key: str) -> Any | None:
"""从缓存获取数据"""
try:
client = await self._ensure_connection()
full_key = self._make_key(key)
data = await client.get(full_key)
async with self._stats_lock:
if data is not None:
self._stats.hits += 1
return self._deserialize(data)
else:
self._stats.misses += 1
return None
except Exception as e:
logger.error(f"Redis GET 失败 [{key}]: {e}")
async with self._stats_lock:
self._stats.misses += 1
return None
async def set(
self,
key: str,
value: Any,
ttl: float | None = None,
) -> None:
"""设置缓存值"""
try:
client = await self._ensure_connection()
full_key = self._make_key(key)
data = self._serialize(value)
# 使用 TTL
expire_time = int(ttl) if ttl is not None else self.default_ttl
await client.setex(full_key, expire_time, data)
logger.debug(f"Redis SET: {key} (TTL={expire_time}s)")
except Exception as e:
logger.error(f"Redis SET 失败 [{key}]: {e}")
async def delete(self, key: str) -> bool:
"""删除缓存条目"""
try:
client = await self._ensure_connection()
full_key = self._make_key(key)
result = await client.delete(full_key)
if result > 0:
async with self._stats_lock:
self._stats.evictions += 1
logger.debug(f"Redis DEL: {key}")
return True
return False
except Exception as e:
logger.error(f"Redis DEL 失败 [{key}]: {e}")
return False
async def exists(self, key: str) -> bool:
"""检查键是否存在"""
try:
client = await self._ensure_connection()
full_key = self._make_key(key)
return bool(await client.exists(full_key))
except Exception as e:
logger.error(f"Redis EXISTS 失败 [{key}]: {e}")
return False
async def clear(self) -> None:
"""清空所有带前缀的缓存"""
try:
client = await self._ensure_connection()
pattern = self._make_key("*")
# 使用 SCAN 避免阻塞
cursor = 0
deleted_count = 0
while True:
cursor, keys = await client.scan(cursor, match=pattern, count=100)
if keys:
await client.delete(*keys)
deleted_count += len(keys)
if cursor == 0:
break
async with self._stats_lock:
self._stats = CacheStats()
logger.info(f"Redis 缓存已清空: 删除 {deleted_count} 个键")
except Exception as e:
logger.error(f"Redis CLEAR 失败: {e}")
async def delete_pattern(self, pattern: str) -> int:
"""删除匹配模式的所有键
Args:
pattern: 键模式(支持 * 通配符)
Returns:
删除的键数量
"""
try:
client = await self._ensure_connection()
full_pattern = self._make_key(pattern)
# 使用 SCAN 避免阻塞
cursor = 0
deleted_count = 0
while True:
cursor, keys = await client.scan(cursor, match=full_pattern, count=100)
if keys:
await client.delete(*keys)
deleted_count += len(keys)
if cursor == 0:
break
async with self._stats_lock:
self._stats.evictions += deleted_count
logger.debug(f"Redis 模式删除: {pattern} -> {deleted_count} 个键")
return deleted_count
except Exception as e:
logger.error(f"Redis 模式删除失败 [{pattern}]: {e}")
return 0
async def mget(self, keys: list[str]) -> dict[str, Any]:
"""批量获取多个键的值"""
if not keys:
return {}
try:
client = await self._ensure_connection()
full_keys = [self._make_key(k) for k in keys]
values = await client.mget(full_keys)
result = {}
hits = 0
misses = 0
for key, value in zip(keys, values):
if value is not None:
result[key] = self._deserialize(value)
hits += 1
else:
misses += 1
async with self._stats_lock:
self._stats.hits += hits
self._stats.misses += misses
return result
except Exception as e:
logger.error(f"Redis MGET 失败: {e}")
return {}
async def mset(
self,
mapping: dict[str, Any],
ttl: float | None = None,
) -> None:
"""批量设置多个键值对"""
if not mapping:
return
try:
client = await self._ensure_connection()
expire_time = int(ttl) if ttl is not None else self.default_ttl
# 使用 pipeline 提高效率
async with client.pipeline(transaction=False) as pipe:
for key, value in mapping.items():
full_key = self._make_key(key)
data = self._serialize(value)
pipe.setex(full_key, expire_time, data)
await pipe.execute()
logger.debug(f"Redis MSET: {len(mapping)} 个键")
except Exception as e:
logger.error(f"Redis MSET 失败: {e}")
async def get_stats(self) -> dict[str, Any]:
"""获取缓存统计信息"""
try:
client = await self._ensure_connection()
# 获取 Redis 服务器信息
info = await client.info("memory")
# keyspace_info 可用于扩展统计, 暂时不获取避免开销
# keyspace_info = await client.info("keyspace")
# 统计带前缀的键数量
pattern = self._make_key("*")
key_count = 0
cursor = 0
while True:
cursor, keys = await client.scan(cursor, match=pattern, count=1000)
key_count += len(keys)
if cursor == 0:
break
async with self._stats_lock:
return {
"backend": "redis",
"hits": self._stats.hits,
"misses": self._stats.misses,
"hit_rate": self._stats.hit_rate,
"evictions": self._stats.evictions,
"key_count": key_count,
"redis_memory_used_mb": info.get("used_memory", 0) / (1024 * 1024),
"redis_memory_peak_mb": info.get("used_memory_peak", 0) / (1024 * 1024),
"redis_connected_clients": info.get("connected_clients", 0),
"key_prefix": self.key_prefix,
"default_ttl": self.default_ttl,
}
except Exception as e:
logger.error(f"获取 Redis 统计信息失败: {e}")
async with self._stats_lock:
return {
"backend": "redis",
"hits": self._stats.hits,
"misses": self._stats.misses,
"hit_rate": self._stats.hit_rate,
"evictions": self._stats.evictions,
"error": str(e),
}
async def close(self) -> None:
"""关闭 Redis 连接"""
self._is_closing = True
if self._client is not None:
try:
await self._client.aclose()
logger.info("Redis 连接已关闭")
except Exception as e:
logger.error(f"关闭 Redis 连接失败: {e}")
finally:
self._client = None
self._pool = None
@property
def backend_type(self) -> str:
"""返回缓存后端类型标识"""
return "redis"
@property
def is_distributed(self) -> bool:
"""Redis 是分布式缓存"""
return True
async def health_check(self) -> bool:
"""健康检查"""
try:
client = await self._ensure_connection()
await client.ping()
return True
except Exception:
return False
async def ttl(self, key: str) -> int:
"""获取键的剩余 TTL
Args:
key: 缓存键
Returns:
剩余秒数,-1 表示无过期时间,-2 表示键不存在
"""
try:
client = await self._ensure_connection()
full_key = self._make_key(key)
return await client.ttl(full_key)
except Exception as e:
logger.error(f"Redis TTL 失败 [{key}]: {e}")
return -2
async def expire(self, key: str, ttl: int) -> bool:
"""更新键的 TTL
Args:
key: 缓存键
ttl: 新的过期时间(秒)
Returns:
是否成功
"""
try:
client = await self._ensure_connection()
full_key = self._make_key(key)
return bool(await client.expire(full_key, ttl))
except Exception as e:
logger.error(f"Redis EXPIRE 失败 [{key}]: {e}")
return False
async def incr(self, key: str, amount: int = 1) -> int:
"""原子递增
Args:
key: 缓存键
amount: 递增量
Returns:
递增后的值
"""
try:
client = await self._ensure_connection()
full_key = self._make_key(key)
return await client.incrby(full_key, amount)
except Exception as e:
logger.error(f"Redis INCR 失败 [{key}]: {e}")
return 0
async def decr(self, key: str, amount: int = 1) -> int:
"""原子递减
Args:
key: 缓存键
amount: 递减量
Returns:
递减后的值
"""
try:
client = await self._ensure_connection()
full_key = self._make_key(key)
return await client.decrby(full_key, amount)
except Exception as e:
logger.error(f"Redis DECR 失败 [{key}]: {e}")
return 0
# 全局 Redis 缓存实例
_global_redis_cache: RedisCache | None = None
_redis_cache_lock = asyncio.Lock()
async def get_redis_cache() -> RedisCache:
"""获取全局 Redis 缓存实例(单例)"""
global _global_redis_cache
if _global_redis_cache is None:
async with _redis_cache_lock:
if _global_redis_cache is None:
# 从配置加载参数
try:
from src.config.config import global_config
assert global_config is not None
db_config = global_config.database
_global_redis_cache = RedisCache(
host=db_config.redis_host,
port=db_config.redis_port,
password=db_config.redis_password or None,
db=db_config.redis_db,
key_prefix=db_config.redis_key_prefix,
default_ttl=db_config.redis_default_ttl,
pool_size=db_config.redis_connection_pool_size,
socket_timeout=db_config.redis_socket_timeout,
ssl=db_config.redis_ssl,
)
except Exception as e:
logger.warning(f"无法从配置加载 Redis 参数,使用默认值: {e}")
_global_redis_cache = RedisCache()
return _global_redis_cache
async def close_redis_cache() -> None:
"""关闭全局 Redis 缓存"""
global _global_redis_cache
if _global_redis_cache is not None:
await _global_redis_cache.close()
_global_redis_cache = None
logger.info("全局 Redis 缓存已关闭")