Method merge_chunks

core/storage.py:950–989

合并 OpenDAL 存储上的分片文件，使用临时文件避免内存问题

(self, upload_id: str, chunk_info: UploadChunk, save_path: str)

        await self.operator.write(chunk_path, chunk_data)

    async def merge_chunks(self, upload_id: str, chunk_info: UploadChunk, save_path: str) -> tuple[str, str]:
        """合并 OpenDAL 存储上的分片文件，使用临时文件避免内存问题"""
        file_sha256 = hashlib.sha256()
        chunk_dir = str(Path(save_path).parent / "chunks" / upload_id)

        # 使用临时文件存储合并数据
        with tempfile.NamedTemporaryFile(delete=False) as temp_file:
            temp_path = temp_file.name

        try:
            async with aiofiles.open(temp_path, 'wb') as out_file:
                for i in range(chunk_info.total_chunks):
                    chunk_path = f"{chunk_dir}/{i}.part"
                    chunk_record = await UploadChunk.filter(upload_id=upload_id, chunk_index=i).first()
                    if not chunk_record:
                        raise ValueError(f"分片{i}记录不存在")

                    try:
                        chunk_data = await self.operator.read(chunk_path)
                    except Exception as e:
                        raise ValueError(f"分片{i}文件不存在: {e}")

                    current_hash = hashlib.sha256(chunk_data).hexdigest()
                    if current_hash != chunk_record.chunk_hash:
                        raise ValueError(f"分片{i}哈希不匹配: 期望 {chunk_record.chunk_hash}, 实际 {current_hash}")

                    file_sha256.update(chunk_data)
                    await out_file.write(chunk_data)
                    del chunk_data  # 释放内存

            # 读取临时文件并写入存储
            async with aiofiles.open(temp_path, 'rb') as f:
                merged_content = await f.read()
            await self.operator.write(save_path, merged_content)
        finally:
            # 清理临时文件
            if os.path.exists(temp_path):
                os.unlink(temp_path)
        
        return save_path, file_sha256.hexdigest()

    async def clean_chunks(self, upload_id: str, save_path: str):
        """清理 OpenDAL 存储上的临时分片文件"""