60 lines
1.5 KiB
Dart
60 lines
1.5 KiB
Dart
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import 'dart:typed_data';
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class RawPacket {
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final int command; // 第三位指令位
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final Uint8List payload; // 数据位
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RawPacket({required this.command, required this.payload});
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}
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class ProtocolDecoder {
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static const head = [0xAB, 0xAA];
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static const tail = [0xAA, 0xAB];
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final List<int> _buffer = [];
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List<RawPacket> decode(List<int> newData) {
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_buffer.addAll(newData);
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List<RawPacket> packets = [];
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while (_buffer.length >= 5) {
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// 最小包长度：头2+指令1+尾2 = 5，加1位数据=6，但是心跳包是AB AA FF AA AB
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// 1. 找头
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int headIdx = -1;
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for (int i = 0; i < _buffer.length - 1; i++) {
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if (_buffer[i] == head[0] && _buffer[i + 1] == head[1]) {
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headIdx = i;
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break;
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}
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}
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if (headIdx == -1) {
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_buffer.clear(); // 没头，全是垃圾数据
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break;
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}
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// 2. 找尾
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int tailIdx = -1;
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for (int i = headIdx + 2; i < _buffer.length - 1; i++) {
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if (_buffer[i] == tail[0] && _buffer[i + 1] == tail[1]) {
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tailIdx = i;
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break;
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}
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}
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if (tailIdx != -1) {
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// 3. 提取
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int cmd = _buffer[headIdx + 2];
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Uint8List payload = Uint8List.fromList(
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_buffer.sublist(headIdx + 3, tailIdx),
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);
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packets.add(RawPacket(command: cmd, payload: payload));
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// 4. 移除已处理部分
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_buffer.removeRange(0, tailIdx + 2);
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} else {
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break; // 还没传完
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}
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}
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return packets;
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}
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}
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