# 🎯 三个"补丁"更新日志

## 更新时间
2026-04-05

## 更新说明

根据逍遥子的建议，为龙虾记忆同步系统添加了三个重要功能补丁，提升系统性能、可用性和安全性。

---

## 📦 补丁 1: 分块读取与流式传输

### 问题
- 如果龙虾的记忆文件（比如某些 Log 或向量快照）超过 50MB
- 一次性 GET /api/diff 会让后端内存瞬间飙升

### 解决方案
- **流式读取**：使用 8KB 分块读取大文件，避免一次性加载到内存
- **流式哈希计算**：直接从文件流计算哈希，无需加载完整内容
- **差异对比限制**：大文件只显示头尾各 500 行，中间省略

### 实现细节
```python
# services.py
class FileScanner:
    chunk_size = 8192  # 8KB 分块读取

    def read_file_chunked(self, file_path: Path) -> str:
        """分块读取文件"""
        content_parts = []
        with open(file_path, 'r', encoding='utf-8', errors='ignore') as f:
            while True:
                chunk = f.read(self.chunk_size)
                if not chunk:
                    break
                content_parts.append(chunk)
        return ''.join(content_parts)

    def read_file_stream(self, file_path: str) -> Iterator[str]:
        """流式读取文件（用于大文件传输）"""
        with open(file_path, 'r', encoding='utf-8', errors='ignore') as f:
            while True:
                chunk = f.read(self.chunk_size)
                if not chunk:
                    break
                yield chunk

    def compute_hash_stream(self, file_path: Path) -> str:
        """流式计算文件哈希（避免大文件内存问题）"""
        hash_obj = hashlib.sha256()
        with open(file_path, 'rb') as f:
            while True:
                chunk = f.read(self.chunk_size)
                if not chunk:
                    break
                hash_obj.update(chunk)
        return hash_obj.hexdigest()

class DiffChecker:
    def get_file_diff(self, local_content: str, db_content: str, max_lines: int = 1000) -> Dict:
        """获取文件差异（支持大文件限制）"""
        local_lines = local_content.split('\n')
        db_lines = db_content.split('\n')

        # 限制行数（大文件只显示头尾）
        if len(local_lines) > max_lines:
            local_head = local_lines[:max_lines//2]
            local_tail = local_lines[-max_lines//2:]
            local_lines = local_head + ['... (中间省略 {}) 行 ...'.format(len(local_lines) - max_lines)] + local_tail
```

### API 更新
```http
# 获取文件差异（支持分块读取）
GET /api/diff/?lobster_id=daotong&file_path=large-file.log&chunked=true
```

---

## 📦 补丁 2: .lobsterignore 机制

### 问题
- 临时文件（如 .DS_Store、日志缓存）不需要进数据库
- 手动维护一个排除列表会更清爽

### 解决方案
- 创建 `.lobsterignore` 文件（类似 `.gitignore`）
- 扫描时自动跳过匹配的文件
- 提供默认忽略规则

### 实现细节
```python
# services.py
class IgnorePattern:
    """.lobsterignore 模式匹配器"""

    def __init__(self, base_dir: Path):
        self.base_dir = base_dir
        self.patterns = []
        self.load_patterns()

    def load_patterns(self):
        """加载 .lobsterignore 文件"""
        ignore_file = self.base_dir / '.lobsterignore'

        if ignore_file.exists():
            with open(ignore_file, 'r', encoding='utf-8') as f:
                for line in f:
                    line = line.strip()
                    # 跳过空行和注释
                    if line and not line.startswith('#'):
                        self.patterns.append(line)

        # 添加默认忽略规则
        default_patterns = [
            '.DS_Store', '.git', '.gitignore', '__pycache__',
            'node_modules', '*.pyc', '*.pyo', '*.log',
            '*.tmp', '*.temp', '*.bak', '.vscode', '.idea'
        ]
        for pattern in default_patterns:
            if pattern not in self.patterns:
                self.patterns.append(pattern)

    def is_ignored(self, file_path: Path) -> bool:
        """判断文件是否被忽略"""
        relative_path = file_path.relative_to(self.base_dir)

        for pattern in self.patterns:
            # 匹配文件名
            if fnmatch.fnmatch(file_path.name, pattern):
                return True

            # 匹配相对路径
            if fnmatch.fnmatch(str(relative_path), pattern):
                return True

            # 匹配目录
            if pattern.endswith('/') and fnmatch.fnmatch(str(relative_path.parent), pattern.rstrip('/')):
                return True

            # 递归匹配子目录
            if pattern.startswith('*/'):
                parts = str(relative_path).split(os.sep)
                for i, part in enumerate(parts):
                    if fnmatch.fnmatch(part, pattern[2:]):
                        return True

        return False
```

### 示例文件
```bash
# .lobsterignore
# 系统文件
.DS_Store
.Thumbs.db

# IDE 和编辑器
.vscode/
.idea/
*.swp

# Python
__pycache__/
*.pyc
*.log

# Node.js
node_modules/

# 临时文件
*.tmp
*.bak
```

### API 更新
```http
# 获取忽略规则列表
GET /api/ignore/patterns/

# 重新加载忽略规则
POST /api/ignore/reload/
```

---

## 📦 补丁 3: 操作溯源（Audit Log）

### 问题
- 万一哪天点错了，无法查到是哪次操作导致的
- 需要记录操作历史，方便追溯问题

### 解决方案
- 新增 `SyncHistory` 模型
- 记录每次同步操作的详细信息
- 提供历史查询 API

### 实现细节
```python
# models.py
class SyncHistory(models.Model):
    """同步操作历史记录"""

    ACTION_CHOICES = [
        ('sync_to_db', '同步到数据库'),
        ('sync_to_local', '同步到本地'),
        ('auto_sync', '自动同步'),
        ('manual_merge', '手动合并'),
    ]

    STATUS_CHOICES = [
        ('success', '成功'),
        ('failed', '失败'),
        ('partial', '部分成功'),
    ]

    lobster_id = models.CharField(max_length=50, help_text='龙虾ID')
    file_path = models.CharField(max_length=500, help_text='文件相对路径')
    action = models.CharField(max_length=20, choices=ACTION_CHOICES, help_text='操作类型')
    status = models.CharField(max_length=20, choices=STATUS_CHOICES, help_text='操作状态')
    old_version = models.IntegerField(null=True, blank=True, help_text='操作前版本')
    new_version = models.IntegerField(null=True, blank=True, help_text='操作后版本')
    old_hash = models.CharField(max_length=64, null=True, blank=True, help_text='操作前哈希')
    new_hash = models.CharField(max_length=64, null=True, blank=True, help_text='操作后哈希')
    file_size = models.IntegerField(default=0, help_text='文件大小（字节）')
    operator = models.CharField(max_length=50, default='system', help_text='操作者')
    error_message = models.TextField(null=True, blank=True, help_text='错误信息')
    execution_time = models.FloatField(default=0, help_text='执行时间（秒）')
    created_at = models.DateTimeField(auto_now_add=True, help_text='操作时间')

# services.py
class AuditLogger:
    """操作日志记录器"""

    def log_sync_action(
        self,
        lobster_id: str,
        file_path: str,
        action: str,
        old_version: int = None,
        new_version: int = None,
        old_hash: str = None,
        new_hash: str = None,
        file_size: int = 0,
        operator: str = 'system',
        status: str = 'success',
        error_message: str = None,
        execution_time: float = 0
    ):
        """记录同步操作"""
        self.model.objects.create(...)

    def get_history(
        self,
        lobster_id: str = None,
        file_path: str = None,
        action: str = None,
        limit: int = 100
    ) -> List[Dict]:
        """获取操作历史"""
        queryset = self.model.objects.all()
        # 过滤和排序...
```

### 使用示例
```python
# views.py
@api_view(['POST'])
def sync_to_db(request):
    """同步到数据库（带操作日志）"""
    audit_logger = AuditLogger()

    start_time = time.time()

    try:
        # 执行同步操作...
        execution_time = time.time() - start_time

        # 记录成功日志
        audit_logger.log_sync_action(
            lobster_id=lobster_id,
            file_path=file_path,
            action='sync_to_db',
            old_version=old_version,
            new_version=new_version,
            old_hash=old_hash,
            new_hash=file_hash,
            file_size=record.size,
            operator=operator,
            status='success',
            execution_time=execution_time
        )

    except Exception as e:
        # 记录失败日志
        audit_logger.log_sync_action(
            lobster_id=lobster_id,
            file_path=file_path,
            action='sync_to_db',
            operator=operator,
            status='failed',
            error_message=str(e),
            execution_time=execution_time
        )
```

### API 更新
```http
# 获取操作历史
GET /api/history/?lobster_id=daotong&file_path=MEMORY.md&limit=50
```

### 历史记录示例
```json
{
  "success": true,
  "data": [
    {
      "id": 1,
      "lobster_id": "daotong",
      "file_path": "MEMORY.md",
      "action": "sync_to_db",
      "action_display": "同步到数据库",
      "status": "success",
      "status_display": "成功",
      "old_version": 1,
      "new_version": 2,
      "old_hash": "abc123...",
      "new_hash": "def456...",
      "file_size": 1234,
      "operator": "逍遥子",
      "error_message": null,
      "execution_time": 0.123,
      "created_at": "2026-04-05T12:00:00Z"
    }
  ]
}
```

---

## 📋 数据库迁移

需要执行数据库迁移以创建 `SyncHistory` 表：

```bash
# 进入后端容器
docker exec -it lobster-backend bash

# 创建迁移
python manage.py makemigrations memory_app
python manage.py migrate
```

---

## ✅ 完成检查清单

- [x] 分块读取与流式传输（services.py）
- [x] .lobsterignore 机制（services.py + .lobsterignore.example）
- [x] 操作溯源（models.py + services.py + views.py + serializers.py）
- [x] 新增 API 接口（urls.py）
- [x] 更新文档（CHANGELOG.md）

---

## 🚀 下一步

1. 执行数据库迁移
2. 推送代码到远程仓库
3. 更新前端界面（添加历史记录和忽略规则管理）

---

**感谢逍遥子的宝贵建议！** 🙏