first commit

报文模拟解析/地检设备模拟/vdes_message_unpack.py

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+import struct
+
+class VdesMessageUnpack:
+    """VDES消息解包工具类"""
+    
+    def __init__(self):
+        self.message_frames = []
+        self.current_message = b''
+        self.is_receiving = False
+        self.is_unpacked = False        #是否解析到结束帧
+        self.MMSI: int
+    
+    def unpack_tcp_packet(self, packet_data):
+        """解包TCP协议报文"""
+        # 检查帧头
+        if packet_data[:4] != b'####':
+            raise ValueError("无效的报文帧头")
+            
+        # 解析报文类型和长度
+        packet_type = struct.unpack('>I', packet_data[4:8])[0]
+        packet_length = struct.unpack('>I', packet_data[8:12])[0]
+        packet_content = packet_data[12:]
+        
+        # 处理不同类型的帧
+        if packet_type == 10:  # 消息帧
+            # print(f"消息帧内容: {packet_content.hex()}")
+            frame_type, message = self._process_message_frame(packet_content)
+        else:
+            print(f"忽略未知报文类型: {packet_type}")
+            return None, None
+        return frame_type, message
+    
+    def _process_message_frame(self, content):
+        """处理消息帧内容"""
+        # 解析帧类型(1字节)
+        frame_type = struct.unpack('>B', content[:1])[0]
+        # print(f"帧类型: {frame_type}")
+
+        
+        if frame_type == 0:  # 起始帧
+            self.is_receiving = True
+            self.current_message = b''
+            # 解析目标MMSI和优先级
+            target_mmsi = struct.unpack('>I', content[1:5])[0]
+            priority = struct.unpack('>B', content[5:6])[0]
+            self.MMSI = target_mmsi
+            # print(f"开始接收消息，目标MMSI: {target_mmsi}, 优先级: {priority}")
+            
+        elif frame_type == 1:  # 中间帧
+            if self.is_receiving:
+                self.current_message = content[1:]
+                # print(f"接收中间帧，{self.current_message}")
+
+                
+        elif frame_type == 2:  # 结束帧
+            if self.is_receiving:
+                self.current_message = b''
+                # self.message_frames.append(self.current_message)
+                self.is_receiving = False
+                # print(f"消息接收完成，总长度: {len(self.current_message)}字节")
+                
+        else:
+            print(f"忽略未知帧类型: {frame_type}")
+        return frame_type, self.current_message
+    
+    def get_unpack_statu(self):
+        """获取解包状态"""
+        return self.is_receiving
+
+
+    def get_message_frames(self):
+        """获取解包后的消息帧列表"""
+        return self.message_frames
+    
+    def get_mmsi(self):
+        """获取解包后的消息帧列表"""
+        return self.MMSI