feat(memory): Introduce configurable memory storage abstraction (#1353)

* feat(内存存储): 添加可配置的内存存储提供者支持

实现内存存储的抽象基类 MemoryStorage 和文件存储实现 FileMemoryStorage
重构内存数据加载和保存逻辑到存储提供者中
添加 storage_class 配置项以支持自定义存储提供者

* refactor(memory): 重构内存存储模块并更新相关测试

将内存存储逻辑从updater模块移动到独立的storage模块
使用存储接口模式替代直接文件操作
更新所有相关测试以使用新的存储接口

* Update backend/packages/harness/deerflow/agents/memory/storage.py

Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com>

* Update backend/packages/harness/deerflow/agents/memory/storage.py

Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com>

* fix(内存存储): 添加线程安全锁并增加测试用例

添加线程锁确保内存存储单例初始化的线程安全
增加对无效代理名称的验证测试
补充单例线程安全性和异常处理的测试用例

* Update backend/tests/test_memory_storage.py

Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com>

* fix(agents): 使用统一模式验证代理名称

修改代理名称验证逻辑以使用仓库中定义的AGENT_NAME_PATTERN模式，确保代码库一致性并防止路径遍历等安全问题。同时更新测试用例以覆盖更多无效名称情况。

---------

Co-authored-by: Willem Jiang <willem.jiang@gmail.com>
Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com>

backend/packages/harness/deerflow/agents/memory/storage.py

@@ -0,0 +1,205 @@
+"""Memory storage providers."""
+
+import abc
+import json
+import logging
+import threading
+from datetime import datetime
+from pathlib import Path
+from typing import Any
+
+from deerflow.config.agents_config import AGENT_NAME_PATTERN
+from deerflow.config.memory_config import get_memory_config
+from deerflow.config.paths import get_paths
+
+logger = logging.getLogger(__name__)
+
+
+def create_empty_memory() -> dict[str, Any]:
+    """Create an empty memory structure."""
+    return {
+        "version": "1.0",
+        "lastUpdated": datetime.utcnow().isoformat() + "Z",
+        "user": {
+            "workContext": {"summary": "", "updatedAt": ""},
+            "personalContext": {"summary": "", "updatedAt": ""},
+            "topOfMind": {"summary": "", "updatedAt": ""},
+        },
+        "history": {
+            "recentMonths": {"summary": "", "updatedAt": ""},
+            "earlierContext": {"summary": "", "updatedAt": ""},
+            "longTermBackground": {"summary": "", "updatedAt": ""},
+        },
+        "facts": [],
+    }
+
+
+class MemoryStorage(abc.ABC):
+    """Abstract base class for memory storage providers."""
+
+    @abc.abstractmethod
+    def load(self, agent_name: str | None = None) -> dict[str, Any]:
+        """Load memory data for the given agent."""
+        pass
+
+    @abc.abstractmethod
+    def reload(self, agent_name: str | None = None) -> dict[str, Any]:
+        """Force reload memory data for the given agent."""
+        pass
+
+    @abc.abstractmethod
+    def save(self, memory_data: dict[str, Any], agent_name: str | None = None) -> bool:
+        """Save memory data for the given agent."""
+        pass
+
+
+class FileMemoryStorage(MemoryStorage):
+    """File-based memory storage provider."""
+
+    def __init__(self):
+        """Initialize the file memory storage."""
+        # Per-agent memory cache: keyed by agent_name (None = global)
+        # Value: (memory_data, file_mtime)
+        self._memory_cache: dict[str | None, tuple[dict[str, Any], float | None]] = {}
+
+    def _validate_agent_name(self, agent_name: str) -> None:
+        """Validate that the agent name is safe to use in filesystem paths.
+
+        Uses the repository's established AGENT_NAME_PATTERN to ensure consistency
+        across the codebase and prevent path traversal or other problematic characters.
+        """
+        if not agent_name:
+            raise ValueError("Agent name must be a non-empty string.")
+        if not AGENT_NAME_PATTERN.match(agent_name):
+            raise ValueError(
+                f"Invalid agent name {agent_name!r}: names must match {AGENT_NAME_PATTERN.pattern}"
+            )
+
+    def _get_memory_file_path(self, agent_name: str | None = None) -> Path:
+        """Get the path to the memory file."""
+        if agent_name is not None:
+            self._validate_agent_name(agent_name)
+            return get_paths().agent_memory_file(agent_name)
+
+        config = get_memory_config()
+        if config.storage_path:
+            p = Path(config.storage_path)
+            return p if p.is_absolute() else get_paths().base_dir / p
+        return get_paths().memory_file
+
+    def _load_memory_from_file(self, agent_name: str | None = None) -> dict[str, Any]:
+        """Load memory data from file."""
+        file_path = self._get_memory_file_path(agent_name)
+
+        if not file_path.exists():
+            return create_empty_memory()
+
+        try:
+            with open(file_path, encoding="utf-8") as f:
+                data = json.load(f)
+            return data
+        except (json.JSONDecodeError, OSError) as e:
+            logger.warning("Failed to load memory file: %s", e)
+            return create_empty_memory()
+
+    def load(self, agent_name: str | None = None) -> dict[str, Any]:
+        """Load memory data (cached with file modification time check)."""
+        file_path = self._get_memory_file_path(agent_name)
+
+        try:
+            current_mtime = file_path.stat().st_mtime if file_path.exists() else None
+        except OSError:
+            current_mtime = None
+
+        cached = self._memory_cache.get(agent_name)
+
+        if cached is None or cached[1] != current_mtime:
+            memory_data = self._load_memory_from_file(agent_name)
+            self._memory_cache[agent_name] = (memory_data, current_mtime)
+            return memory_data
+
+        return cached[0]
+
+    def reload(self, agent_name: str | None = None) -> dict[str, Any]:
+        """Reload memory data from file, forcing cache invalidation."""
+        file_path = self._get_memory_file_path(agent_name)
+        memory_data = self._load_memory_from_file(agent_name)
+
+        try:
+            mtime = file_path.stat().st_mtime if file_path.exists() else None
+        except OSError:
+            mtime = None
+
+        self._memory_cache[agent_name] = (memory_data, mtime)
+        return memory_data
+
+    def save(self, memory_data: dict[str, Any], agent_name: str | None = None) -> bool:
+        """Save memory data to file and update cache."""
+        file_path = self._get_memory_file_path(agent_name)
+
+        try:
+            file_path.parent.mkdir(parents=True, exist_ok=True)
+            memory_data["lastUpdated"] = datetime.utcnow().isoformat() + "Z"
+
+            temp_path = file_path.with_suffix(".tmp")
+            with open(temp_path, "w", encoding="utf-8") as f:
+                json.dump(memory_data, f, indent=2, ensure_ascii=False)
+
+            temp_path.replace(file_path)
+
+            try:
+                mtime = file_path.stat().st_mtime
+            except OSError:
+                mtime = None
+
+            self._memory_cache[agent_name] = (memory_data, mtime)
+            logger.info("Memory saved to %s", file_path)
+            return True
+        except OSError as e:
+            logger.error("Failed to save memory file: %s", e)
+            return False
+
+
+_storage_instance: MemoryStorage | None = None
+_storage_lock = threading.Lock()
+
+
+def get_memory_storage() -> MemoryStorage:
+    """Get the configured memory storage instance."""
+    global _storage_instance
+    if _storage_instance is not None:
+        return _storage_instance
+
+    with _storage_lock:
+        if _storage_instance is not None:
+            return _storage_instance
+
+        config = get_memory_config()
+        storage_class_path = config.storage_class
+
+        try:
+            module_path, class_name = storage_class_path.rsplit(".", 1)
+            import importlib
+            module = importlib.import_module(module_path)
+            storage_class = getattr(module, class_name)
+
+            # Validate that the configured storage is a MemoryStorage implementation
+            if not isinstance(storage_class, type):
+                raise TypeError(
+                    f"Configured memory storage '{storage_class_path}' is not a class: {storage_class!r}"
+                )
+            if not issubclass(storage_class, MemoryStorage):
+                raise TypeError(
+                    f"Configured memory storage '{storage_class_path}' is not a subclass of MemoryStorage"
+                )
+
+            _storage_instance = storage_class()
+        except Exception as e:
+            logger.error(
+                "Failed to load memory storage %s, falling back to FileMemoryStorage: %s",
+                storage_class_path,
+                e,
+            )
+            _storage_instance = FileMemoryStorage()
+
+    return _storage_instance