优化 Windows 平台的文件替换操作，增加安全的原子写入功能，改进备份文件清理机制

src/memory_graph/storage/persistence.py

@@ -6,6 +6,9 @@ from __future__ import annotations
 
 import asyncio
 import json
+import os
+import sys
+from collections.abc import Callable
 from datetime import datetime
 from pathlib import Path
 
@@ -18,6 +21,106 @@ from src.memory_graph.storage.graph_store import GraphStore
 
 logger = get_logger(__name__)
 
+# Windows 平台检测
+IS_WINDOWS = sys.platform == "win32"
+
+# Windows 平台检测
+IS_WINDOWS = sys.platform == "win32"
+
+
+async def safe_atomic_write(temp_path: Path, target_path: Path, max_retries: int = 5) -> None:
+    """
+    安全的原子写入操作（针对 Windows 文件锁优化）
+
+    Args:
+        temp_path: 临时文件路径
+        target_path: 目标文件路径
+        max_retries: 最大重试次数
+
+    Raises:
+        OSError: 所有重试都失败时抛出
+    """
+    last_error: Exception | None = None
+
+    for attempt in range(max_retries):
+        try:
+            if IS_WINDOWS:
+                # Windows 特殊处理：多步骤原子替换
+                if target_path.exists():
+                    # 策略1: 尝试直接删除
+                    try:
+                        os.unlink(target_path)
+                    except OSError:
+                        # 策略2: 重命名为 .old 文件
+                        old_file = target_path.with_suffix(".old")
+                        try:
+                            if old_file.exists():
+                                os.unlink(old_file)
+                            target_path.rename(old_file)
+                        except OSError:
+                            # 策略3: 使用时间戳后缀
+                            from datetime import datetime
+                            backup_file = target_path.with_suffix(f".bak_{datetime.now().strftime('%H%M%S')}")
+                            target_path.rename(backup_file)
+                            # 标记稍后清理
+                            asyncio.create_task(_cleanup_backup_files(target_path.parent, target_path.stem))
+
+                # 执行重命名
+                temp_path.rename(target_path)
+            else:
+                # Unix/Linux: 直接使用 replace (原子操作)
+                temp_path.replace(target_path)
+
+            # 成功
+            return
+
+        except OSError as e:
+            last_error = e
+            if attempt < max_retries - 1:
+                # 指数退避重试
+                wait_time = 0.05 * (2 ** attempt)
+                logger.warning(
+                    f"文件替换失败 (尝试 {attempt + 1}/{max_retries}), "
+                    f"等待 {wait_time:.3f}s 后重试: {e}"
+                )
+                await asyncio.sleep(wait_time)
+            else:
+                logger.error(f"文件替换失败，已达到最大重试次数 ({max_retries})")
+
+    # 所有重试失败
+    if last_error:
+        raise last_error
+    raise OSError(f"文件替换失败: {temp_path} -> {target_path}")
+
+
+async def _cleanup_backup_files(directory: Path, file_stem: str, keep_recent: int = 3) -> None:
+    """
+    清理临时备份文件（后台异步任务）
+
+    Args:
+        directory: 目录路径
+        file_stem: 文件主名（不含扩展名）
+        keep_recent: 保留最近的文件数量
+    """
+    try:
+        # 延迟执行，避免立即清理可能仍在使用的文件
+        await asyncio.sleep(5)
+
+        # 查找所有备份文件
+        pattern = f"{file_stem}.bak_*"
+        backup_files = sorted(directory.glob(pattern), key=lambda p: p.stat().st_mtime, reverse=True)
+
+        # 删除超出保留数量的文件
+        for old_file in backup_files[keep_recent:]:
+            try:
+                old_file.unlink()
+                logger.debug(f"已清理旧备份文件: {old_file.name}")
+            except OSError as e:
+                logger.debug(f"清理备份文件失败: {old_file.name}, {e}")
+
+    except Exception as e:
+        logger.debug(f"清理备份文件任务失败: {e}")
+
 
 class PersistenceManager:
     """
@@ -90,26 +193,10 @@ class PersistenceManager:
                 async with aiofiles.open(temp_file, "wb") as f:
                     await f.write(json_data)
 
-                # 在Windows上，确保目标文件没有被占用
-                if self.graph_file.exists():
-                    import os
-                    try:
-                        os.unlink(self.graph_file)
-                    except OSError:
-                        # 如果无法删除，等待一小段时间再重试
-                        await asyncio.sleep(0.1)
-                        try:
-                            os.unlink(self.graph_file)
-                        except OSError:
-                            # 如果还是失败，使用备用策略
-                            backup_file = self.graph_file.with_suffix(".bak")
-                            if backup_file.exists():
-                                os.unlink(backup_file)
-                            self.graph_file.rename(backup_file)
+                # 使用安全的原子写入
+                await safe_atomic_write(temp_file, self.graph_file)
 
-                temp_file.replace(self.graph_file)
-
-                logger.info(f"图数据已保存: {self.graph_file}, 大小: {len(json_data) / 1024:.2f} KB")
+                logger.debug(f"图数据已保存: {self.graph_file}, 大小: {len(json_data) / 1024:.2f} KB")
 
             except Exception as e:
                 logger.error(f"保存图数据失败: {e}", exc_info=True)
@@ -127,36 +214,41 @@ class PersistenceManager:
             return None
 
         async with self._file_lock:  # 使用文件锁防止并发访问
-                try:
-                    # 读取文件，添加重试机制处理可能的文件锁定
-                    max_retries = 3
-                    for attempt in range(max_retries):
-                        try:
-                            async with aiofiles.open(self.graph_file, "rb") as f:
-                                json_data = await f.read()
-                            data = orjson.loads(json_data)
-                            break
-                        except OSError as e:
-                            if attempt == max_retries - 1:
-                                raise
-                            logger.warning(f"读取图数据文件失败 (尝试 {attempt + 1}/{max_retries}): {e}")
-                            await asyncio.sleep(0.1 * (attempt + 1))
+            try:
+                # 读取文件，添加重试机制处理可能的文件锁定
+                data = None
+                max_retries = 3
+                for attempt in range(max_retries):
+                    try:
+                        async with aiofiles.open(self.graph_file, "rb") as f:
+                            json_data = await f.read()
+                        data = orjson.loads(json_data)
+                        break
+                    except OSError as e:
+                        if attempt == max_retries - 1:
+                            raise
+                        logger.warning(f"读取图数据文件失败 (尝试 {attempt + 1}/{max_retries}): {e}")
+                        await asyncio.sleep(0.1 * (attempt + 1))
 
-                    # 检查版本（未来可能需要数据迁移）
-                    version = data.get("metadata", {}).get("version", "unknown")
-                    logger.info(f"加载图数据: version={version}")
-
-                    # 恢复图存储
-                    graph_store = GraphStore.from_dict(data)
-
-                    logger.info(f"图数据加载完成: {graph_store.get_statistics()}")
-                    return graph_store
-
-                except Exception as e:
-                    logger.error(f"加载图数据失败: {e}", exc_info=True)
-                    # 尝试加载备份
+                if data is None:
+                    logger.error("无法读取图数据文件")
                     return await self._load_from_backup()
 
+                # 检查版本（未来可能需要数据迁移）
+                version = data.get("metadata", {}).get("version", "unknown")
+                logger.info(f"加载图数据: version={version}")
+
+                # 恢复图存储
+                graph_store = GraphStore.from_dict(data)
+
+                logger.info(f"图数据加载完成: {graph_store.get_statistics()}")
+                return graph_store
+
+            except Exception as e:
+                logger.error(f"加载图数据失败: {e}", exc_info=True)
+                # 尝试加载备份
+                return await self._load_from_backup()
+
     async def save_staged_memories(self, staged_memories: list[StagedMemory]) -> None:
         """
         保存临时记忆列表
@@ -181,24 +273,8 @@ class PersistenceManager:
                 async with aiofiles.open(temp_file, "wb") as f:
                     await f.write(json_data)
 
-                # 在Windows上，确保目标文件没有被占用
-                if self.staged_file.exists():
-                    import os
-                    try:
-                        os.unlink(self.staged_file)
-                    except OSError:
-                        # 如果无法删除，等待一小段时间再重试
-                        await asyncio.sleep(0.1)
-                        try:
-                            os.unlink(self.staged_file)
-                        except OSError:
-                            # 如果还是失败，使用备用策略
-                            backup_file = self.staged_file.with_suffix(".bak")
-                            if backup_file.exists():
-                                os.unlink(backup_file)
-                            self.staged_file.rename(backup_file)
-
-                temp_file.replace(self.staged_file)
+                # 使用安全的原子写入
+                await safe_atomic_write(temp_file, self.staged_file)
 
                 logger.info(f"临时记忆已保存: {len(staged_memories)} 条")
 
@@ -218,30 +294,35 @@ class PersistenceManager:
             return []
 
         async with self._file_lock:  # 使用文件锁防止并发访问
-                try:
-                    # 读取文件，添加重试机制处理可能的文件锁定
-                    max_retries = 3
-                    for attempt in range(max_retries):
-                        try:
-                            async with aiofiles.open(self.staged_file, "rb") as f:
-                                json_data = await f.read()
-                            data = orjson.loads(json_data)
-                            break
-                        except OSError as e:
-                            if attempt == max_retries - 1:
-                                raise
-                            logger.warning(f"读取临时记忆文件失败 (尝试 {attempt + 1}/{max_retries}): {e}")
-                            await asyncio.sleep(0.1 * (attempt + 1))
+            try:
+                # 读取文件，添加重试机制处理可能的文件锁定
+                data = None
+                max_retries = 3
+                for attempt in range(max_retries):
+                    try:
+                        async with aiofiles.open(self.staged_file, "rb") as f:
+                            json_data = await f.read()
+                        data = orjson.loads(json_data)
+                        break
+                    except OSError as e:
+                        if attempt == max_retries - 1:
+                            raise
+                        logger.warning(f"读取临时记忆文件失败 (尝试 {attempt + 1}/{max_retries}): {e}")
+                        await asyncio.sleep(0.1 * (attempt + 1))
 
-                    staged_memories = [StagedMemory.from_dict(sm) for sm in data.get("staged_memories", [])]
-
-                    logger.info(f"临时记忆加载完成: {len(staged_memories)} 条")
-                    return staged_memories
-
-                except Exception as e:
-                    logger.error(f"加载临时记忆失败: {e}", exc_info=True)
+                if data is None:
+                    logger.error("无法读取临时记忆文件")
                     return []
 
+                staged_memories = [StagedMemory.from_dict(sm) for sm in data.get("staged_memories", [])]
+
+                logger.info(f"临时记忆加载完成: {len(staged_memories)} 条")
+                return staged_memories
+
+            except Exception as e:
+                logger.error(f"加载临时记忆失败: {e}", exc_info=True)
+                return []
+
     async def create_backup(self) -> Path | None:
         """
         创建当前数据的备份
@@ -286,6 +367,7 @@ class PersistenceManager:
             logger.warning(f"尝试从备份恢复: {latest_backup}")
 
             # 读取备份文件，添加重试机制
+            data = None
             max_retries = 3
             for attempt in range(max_retries):
                 try:
@@ -299,6 +381,10 @@ class PersistenceManager:
                     logger.warning(f"读取备份文件失败 (尝试 {attempt + 1}/{max_retries}): {e}")
                     await asyncio.sleep(0.1 * (attempt + 1))
 
+            if data is None:
+                logger.error("无法从备份读取数据")
+                return None
+
             graph_store = GraphStore.from_dict(data)
             logger.info(f"从备份恢复成功: {graph_store.get_statistics()}")
 
@@ -329,7 +415,7 @@ class PersistenceManager:
     async def start_auto_save(
         self,
         graph_store: GraphStore,
-        staged_memories_getter: callable | None = None,
+        staged_memories_getter: Callable[[], list[StagedMemory]] | None = None,
     ) -> None:
         """
         启动自动保存任务