210 lines
11 KiB
Python
210 lines
11 KiB
Python
from typing import Optional, Tuple
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import logging
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from frame import FrameFormat
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class FrameFinder:
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"""帧查找器 - 在数据缓冲区中查找符合帧格式的数据"""
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def __init__(self):
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"""初始化帧查找器"""
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self.frame_length = FrameFormat.FIXED_SIZE + FrameFormat.DATA_SIZE
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self.frame_header = FrameFormat.FRAME_HEADER
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self.logger = logging.getLogger(__name__)
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# 设置日志级别为INFO，只有在需要调试时才改为DEBUG
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self.logger.setLevel(logging.INFO)
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def find_frame_in_buffer(self, buffer: bytes, start_pos: int = 0) -> Tuple[Optional[bytes], int]:
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"""
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在给定的缓冲区数据中查找下一个有效帧
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Args:
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buffer: 要搜索的缓冲区数据
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start_pos: 开始搜索的位置
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Returns:
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Tuple[Optional[bytes], int]:
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- 找到的帧数据（如果没找到则为None）
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- 下一次搜索的起始位置（如果找到帧，则是帧后的位置；如果没找到，则是需要保留的数据起始位置）
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"""
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buffer_size = len(buffer)
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current_pos = start_pos
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while current_pos < buffer_size:
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# 检查当前位置是否有足够的数据
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if buffer_size - current_pos < len(self.frame_header):
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if self.logger.isEnabledFor(logging.DEBUG):
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self.logger.debug(f"剩余数据不足帧头长度: {buffer_size - current_pos} < {len(self.frame_header)}")
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return None, current_pos
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# 在当前位置查找帧头
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header_pos = self._find_header(buffer, current_pos)
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if header_pos is None:
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if self.logger.isEnabledFor(logging.DEBUG):
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self.logger.debug(f"未找到帧头，将移除所有数据 ({buffer_size - current_pos} 字节)")
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if buffer_size - current_pos > 0:
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self.logger.debug(f"移除的数据: {buffer[current_pos:].hex()}")
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return None, buffer_size
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if self.logger.isEnabledFor(logging.DEBUG):
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self.logger.debug(f"找到帧头位置: {header_pos}")
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if header_pos > current_pos:
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removed_data = buffer[current_pos:header_pos]
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self.logger.debug(f"将移除帧头前的无效数据: {removed_data.hex() if len(removed_data) > 0 else '无'} ({len(removed_data)} 字节)")
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# 检查是否有完整帧的数据
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if buffer_size - header_pos < self.frame_length:
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if self.logger.isEnabledFor(logging.DEBUG):
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self.logger.debug(f"帧头后数据不足: {buffer_size - header_pos} < {self.frame_length}")
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self.logger.debug(f"保留从位置 {header_pos} 开始的数据: {buffer[header_pos:].hex()}")
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return None, header_pos
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# 提取并验证帧
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frame_data = buffer[header_pos:header_pos + self.frame_length]
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if self._verify_frame(frame_data):
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if self.logger.isEnabledFor(logging.DEBUG):
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self.logger.debug(f"找到有效帧: {frame_data.hex()}")
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next_pos = header_pos + self.frame_length
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remaining_data = buffer[next_pos:] if next_pos < buffer_size else b''
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self.logger.debug(f"处理完帧后剩余数据: {remaining_data.hex() if remaining_data else '无'} ({len(remaining_data)} 字节)")
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return frame_data, header_pos + self.frame_length
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# 帧验证失败，从下一个位置继续查找
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if self.logger.isEnabledFor(logging.DEBUG):
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self.logger.debug(f"帧验证失败，从下一个位置继续查找")
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# 防止在同一位置反复查找
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current_pos = header_pos + 1 # 从帧头后的下一个字节开始查找
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if current_pos >= buffer_size:
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if self.logger.isEnabledFor(logging.DEBUG):
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self.logger.debug(f"搜索位置已到达缓冲区末尾，将移除所有数据")
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return None, buffer_size
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if self.logger.isEnabledFor(logging.DEBUG):
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removed_data = buffer[header_pos:current_pos]
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self.logger.debug(f"移除无效帧头数据: {removed_data.hex()} ({len(removed_data)} 字节)")
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# 如果遍历完整个缓冲区都没有找到有效帧
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if self.logger.isEnabledFor(logging.DEBUG):
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self.logger.debug(f"遍历完整个缓冲区未找到有效帧")
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return None, buffer_size
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def _find_header(self, buffer: bytes, start_pos: int) -> Optional[int]:
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"""
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在缓冲区中查找帧头
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Args:
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buffer: 要搜索的缓冲区数据
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start_pos: 开始搜索的位置
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Returns:
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Optional[int]: 帧头位置，如果未找到则返回None
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"""
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header_len = len(self.frame_header)
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buffer_size = len(buffer)
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# 确保有足够的数据来查找帧头
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if buffer_size - start_pos < header_len:
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if self.logger.isEnabledFor(logging.DEBUG):
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self.logger.debug(f"剩余数据不足帧头长度: {buffer_size - start_pos} < {header_len}")
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return None
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# 从起始位置开始查找帧头
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for i in range(start_pos, buffer_size - header_len + 1):
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if buffer[i:i+header_len] == self.frame_header:
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if self.logger.isEnabledFor(logging.DEBUG):
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self.logger.debug(f"在位置 {i} 找到帧头: {buffer[i:i+header_len].hex()}")
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# 显示帧头前后的数据
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before = buffer[max(0, i-4):i]
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after = buffer[i+header_len:i+header_len+4]
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self.logger.debug(f"帧头前4字节: {before.hex() if before else '无'}")
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self.logger.debug(f"帧头后4字节: {after.hex() if after else '无'}")
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return i
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if self.logger.isEnabledFor(logging.DEBUG):
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self.logger.debug(f"从位置 {start_pos} 开始未找到帧头")
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self.logger.debug(f"剩余数据: {buffer[start_pos:].hex()[:100]}...")
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self.logger.debug(f"剩余数据长度: {buffer_size - start_pos}")
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return None
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def _verify_frame(self, frame_data: bytes) -> bool:
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"""
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验证帧的有效性
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Args:
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frame_data: 要验证的帧数据
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Returns:
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bool: 帧是否有效
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"""
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# 使用FrameFormat验证帧
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frame = FrameFormat.parse_frame(frame_data)
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if frame is None and self.logger.isEnabledFor(logging.DEBUG):
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self.logger.debug(f"帧验证失败: {frame_data.hex()}")
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return frame is not None
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if __name__ == "__main__":
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# 使用示例
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import logging
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# 配置日志
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logging.basicConfig(
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level=logging.DEBUG,
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format='%(asctime)s - %(levelname)s - %(message)s'
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)
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# 创建帧查找器实例
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finder = FrameFinder()
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# test_data = bytes.fromhex("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")
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with open("test_data/test_frames.bin", "rb") as f:
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test_data = f.read()
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print("初始测试数据:")
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print("总长度:", len(test_data))
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print("数据:", test_data.hex())
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print("\n开始查找帧:")
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# 模拟实际使用场景，从不同位置开始查找
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remaining_data = test_data
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frame_count = 0
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while len(remaining_data) > 0:
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frame, next_pos = finder.find_frame_in_buffer(remaining_data)
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if frame:
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frame_count += 1
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print(f"\n找到第 {frame_count} 个帧:")
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print(f"帧数据: {frame.hex()}")
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print(f"下一个搜索位置: {next_pos}")
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# 解析帧内容
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parsed_frame = FrameFormat.parse_frame(frame)
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if parsed_frame:
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print(f"命令码: 0x{parsed_frame.command:08X}")
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print(f"长度: {parsed_frame.length}")
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print(f"帧IDX: {parsed_frame.frame_idx}")
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print("通道数据:")
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for i, value in enumerate(parsed_frame.channels):
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print(f"通道 {i+1}: 0x{value:08X}")
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print(f"校验和: 0x{parsed_frame.checksum:02X}")
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# 更新剩余数据
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remaining_data = remaining_data[next_pos:]
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print(f"\n剩余数据: ({len(remaining_data)} 字节)")
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if remaining_data:
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# print(f"数据: {remaining_data.hex()}")
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pass
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else:
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# 如果没有找到帧，next_pos 表示需要保留的数据起始位置
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if next_pos == len(remaining_data):
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print("\n没有更多帧了")
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break
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elif next_pos == 0:
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# 如果next_pos为0，说明剩余数据不足一个帧头，直接结束
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print("\n剩余数据不足一个帧头，结束查找")
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break
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else:
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# 移除无效数据
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removed_data = remaining_data[:next_pos]
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if removed_data:
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print(f"\n移除 {len(removed_data)} 字节无效数据: {removed_data.hex()}")
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remaining_data = remaining_data[next_pos:]
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print(f"剩余数据: ({len(remaining_data)} 字节)")
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if remaining_data:
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# print(f"数据: {remaining_data.hex()}")
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pass
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print(f"\n总共找到 {frame_count} 个帧") |