from typing import Optional, Tuple import logging from frame import FrameFormat class FrameFinder: """帧查找器 - 在数据缓冲区中查找符合帧格式的数据""" def __init__(self, num_channels: int = 17): """ 初始化帧查找器 Args: num_channels: 通道数量，默认为8 """ self.frame_format = FrameFormat(num_channels) self.frame_length = self.frame_format.FIXED_SIZE + self.frame_format.DATA_SIZE self.frame_header = self.frame_format.FRAME_HEADER self.logger = logging.getLogger(__name__) # 设置日志级别为INFO，只有在需要调试时才改为DEBUG self.logger.setLevel(logging.INFO) def find_frame_in_buffer(self, buffer: bytes, start_pos: int = 0) -> Tuple[Optional[bytes], int]: """ 在给定的缓冲区数据中查找下一个有效帧 Args: buffer: 要搜索的缓冲区数据 start_pos: 开始搜索的位置 Returns: Tuple[Optional[bytes], int]: - 找到的帧数据（如果没找到则为None） - 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） """ buffer_size = len(buffer) current_pos = start_pos while current_pos < buffer_size: # 检查当前位置是否有足够的数据 if buffer_size - current_pos < len(self.frame_header): if self.logger.isEnabledFor(logging.DEBUG): self.logger.debug(f"剩余数据不足帧头长度: {buffer_size - current_pos} < {len(self.frame_header)}") return None, current_pos # 在当前位置查找帧头 header_pos = self._find_header(buffer, current_pos) if header_pos is None: if self.logger.isEnabledFor(logging.DEBUG): self.logger.debug(f"未找到帧头，将移除所有数据 ({buffer_size - current_pos} 字节)") if buffer_size - current_pos > 0: self.logger.debug(f"移除的数据: {buffer[current_pos:].hex()}") return None, buffer_size if self.logger.isEnabledFor(logging.DEBUG): self.logger.debug(f"找到帧头位置: {header_pos}") if header_pos > current_pos: removed_data = buffer[current_pos:header_pos] 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)") # 检查是否有完整帧的数据 if buffer_size - header_pos < self.frame_length: if self.logger.isEnabledFor(logging.DEBUG): self.logger.debug(f"帧头后数据不足: {buffer_size - header_pos} < {self.frame_length}") self.logger.debug(f"保留从位置 {header_pos} 开始的数据: {buffer[header_pos:].hex()}") return None, header_pos # 提取并验证帧 frame_data = buffer[header_pos:header_pos + self.frame_length] if self._verify_frame(frame_data): if self.logger.isEnabledFor(logging.DEBUG): self.logger.debug(f"找到有效帧: {frame_data.hex()}") next_pos = header_pos + self.frame_length remaining_data = buffer[next_pos:] if next_pos < buffer_size else b'' 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)") return frame_data, header_pos + self.frame_length # 帧验证失败，从下一个位置继续查找 if self.logger.isEnabledFor(logging.DEBUG): self.logger.debug(f"帧验证失败，从下一个位置继续查找") # 防止在同一位置反复查找 current_pos = header_pos + 1 # 从帧头后的下一个字节开始查找 if current_pos >= buffer_size: if self.logger.isEnabledFor(logging.DEBUG): self.logger.debug(f"搜索位置已到达缓冲区末尾，将移除所有数据") return None, buffer_size if self.logger.isEnabledFor(logging.DEBUG): removed_data = buffer[header_pos:current_pos] self.logger.debug(f"移除无效帧头数据: {removed_data.hex()} ({len(removed_data)} 字节)") # 如果遍历完整个缓冲区都没有找到有效帧 if self.logger.isEnabledFor(logging.DEBUG): self.logger.debug(f"遍历完整个缓冲区未找到有效帧") return None, buffer_size def _find_header(self, buffer: bytes, start_pos: int) -> Optional[int]: """ 在缓冲区中查找帧头 Args: buffer: 要搜索的缓冲区数据 start_pos: 开始搜索的位置 Returns: Optional[int]: 帧头位置，如果未找到则返回None """ header_len = len(self.frame_header) buffer_size = len(buffer) # 确保有足够的数据来查找帧头 if buffer_size - start_pos < header_len: if self.logger.isEnabledFor(logging.DEBUG): self.logger.debug(f"剩余数据不足帧头长度: {buffer_size - start_pos} < {header_len}") return None # 从起始位置开始查找帧头 for i in range(start_pos, buffer_size - header_len + 1): if buffer[i:i+header_len] == self.frame_header: if self.logger.isEnabledFor(logging.DEBUG): self.logger.debug(f"在位置 {i} 找到帧头: {buffer[i:i+header_len].hex()}") # 显示帧头前后的数据 before = buffer[max(0, i-4):i] after = buffer[i+header_len:i+header_len+4] self.logger.debug(f"帧头前4字节: {before.hex() if before else '无'}") self.logger.debug(f"帧头后4字节: {after.hex() if after else '无'}") return i if self.logger.isEnabledFor(logging.DEBUG): self.logger.debug(f"从位置 {start_pos} 开始未找到帧头") self.logger.debug(f"剩余数据: {buffer[start_pos:].hex()[:100]}...") self.logger.debug(f"剩余数据长度: {buffer_size - start_pos}") return None def _verify_frame(self, frame_data: bytes) -> bool: """ 验证帧的有效性 Args: frame_data: 要验证的帧数据 Returns: bool: 帧是否有效 """ # 使用FrameFormat验证帧 frame = FrameFormat.parse_frame(frame_data, self.frame_format.CHANNEL_COUNT) if frame is None and self.logger.isEnabledFor(logging.DEBUG): self.logger.debug(f"帧验证失败: {frame_data.hex()}") return frame is not None if __name__ == "__main__": # 使用示例 import logging # 配置日志 logging.basicConfig( level=logging.DEBUG, format='%(asctime)s - %(levelname)s - %(message)s' ) # 创建帧查找器实例 finder = FrameFinder(num_channels=24) # with open("test_data/test_frames.bin", "rb") as f: # test_data = f.read() # test_data_hex = "AA AA AA AA 02 00 00 00 49 00 00 00 B1 87 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 2B AA AA AA AA 02 00 00 00 49 00 00 00 B2 87 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 2C AA AA AA AA 02 00 00 00 49 00 00 00 B3 87 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 2D AA AA AA AA 02 00 00 00 49 00 00 00 B4 87 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 2E" test_data_hex = '''AA AA AA AA 02 00 00 00 65 00 00 00 00 00 00 00 E1 FE FF FF 20 01 00 00 E1 FB FF FF 00 00 00 00 A0 FE FF FF A1 FD FF FF C0 02 00 00 C1 FF FF FF 41 FF FF FF 61 FF FF FF 60 FF FF FF 60 FF FF FF 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 F5''' test_data = bytes.fromhex(test_data_hex) print("初始测试数据:") print("总长度:", len(test_data)) print("数据:", test_data.hex()) print("\n开始查找帧:") # 模拟实际使用场景，从不同位置开始查找 remaining_data = test_data frame_count = 0 while len(remaining_data) > 0: frame, next_pos = finder.find_frame_in_buffer(remaining_data) if frame: frame_count += 1 print(f"\n找到第 {frame_count} 个帧:") print(f"帧数据: {frame.hex()}") print(f"下一个搜索位置: {next_pos}") print(frame) # 解析帧内容 parsed_frame = FrameFormat.parse_frame(frame, finder.frame_format.CHANNEL_COUNT) if parsed_frame: print(f"命令码: 0x{parsed_frame.command:08X}") print(f"长度: {parsed_frame.length}") print(f"帧IDX: {parsed_frame.frame_idx}") print("通道数据:") for i, value in enumerate(parsed_frame.channels): print(f"通道 {i+1}: 0x{value:08X}") print(f"校验和: 0x{parsed_frame.checksum:02X}") # 更新剩余数据 remaining_data = remaining_data[next_pos:] print(f"\n剩余数据: ({len(remaining_data)} 字节)") if remaining_data: # print(f"数据: {remaining_data.hex()}") pass else: # 如果没有找到帧，next_pos 表示需要保留的数据起始位置 if next_pos == len(remaining_data): print("\n没有更多帧了") break elif next_pos == 0: # 如果next_pos为0，说明剩余数据不足一个帧头，直接结束 print("\n剩余数据不足一个帧头，结束查找") break else: # 移除无效数据 removed_data = remaining_data[:next_pos] if removed_data: print(f"\n移除 {len(removed_data)} 字节无效数据: {removed_data.hex()}") remaining_data = remaining_data[next_pos:] print(f"剩余数据: ({len(remaining_data)} 字节)") if remaining_data: # print(f"数据: {remaining_data.hex()}") pass print(f"\n总共找到 {frame_count} 个帧")