74 lines
2.4 KiB
Python
74 lines
2.4 KiB
Python
import os
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def extract_drive_letter(path: str) -> str:
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"""从绝对路径中提取盘符"""
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drive = os.path.splitdrive(path)[0]
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if not drive:
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raise ValueError(f"无法从路径中提取盘符：{path}")
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return drive[0].upper() # 返回 'Y'
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def CopyFileFromBytes(source_data_dict, target_path):
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"""
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根据起始字节和长度，从磁盘中读取数据并保存为目标文件
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:param source_data_dict: 包含源数据信息的字典
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:param target_path: 目标文件夹路径
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"""
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start_byte = source_data_dict.get("start_byte")
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byte_length = source_data_dict.get("length")
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absolute_path = source_data_dict.get("absolute_path")
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file_name = source_data_dict.get("filename")
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if byte_length <= 0:
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print("错误：字节长度无效")
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return
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if not absolute_path or not file_name:
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print("错误：缺少必要的文件信息")
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return
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source_disk_path = extract_drive_letter(absolute_path)
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target_file_path = os.path.join(target_path, file_name)
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try:
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# 创建目标目录（如果不存在）
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os.makedirs(target_path, exist_ok=True)
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with open(fr"\\.\{source_disk_path}:", 'rb') as disk:
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disk.seek(start_byte)
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with open(target_file_path, 'wb') as f:
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remaining = byte_length
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CHUNK_SIZE = 1024 * 1024 # 1MB
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while remaining > 0:
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read_size = min(CHUNK_SIZE, remaining)
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chunk = disk.read(read_size)
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if not chunk:
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print("警告：读取到空数据，可能已到达磁盘末尾。")
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break
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f.write(chunk)
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remaining -= len(chunk)
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print(
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f"成功：已从字节偏移量 {start_byte} 读取 {byte_length} 字节，保存为 {target_file_path}")
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except PermissionError:
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print("错误：需要管理员权限访问磁盘设备，请以管理员身份运行此程序")
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except Exception as e:
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print(f"发生错误: {str(e)}")
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if __name__ == "__main__":
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test_dict = {
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'absolute_path': 'Y:\\CloudMusic\\Aaron Zigman - Main Title.mp3',
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'filename': 'Aaron Zigman - Main Title.mp3',
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'extent_count': 1,
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'start_byte': 687685632,
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'length': 7163904,
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'fragment_index': 1
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}
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CopyFileFromBytes(test_dict, target_path=r"Z:\RecoveredFiles")
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