feat: initial project setup - Komet Flutter app

lib/core/protocol/packet.dart

@@ -0,0 +1,133 @@
+import 'dart:typed_data';
+import 'package:dart_lz4/dart_lz4.dart';
+import 'package:msgpack_dart/msgpack_dart.dart' as msgpack;
+
+final int apiVersion = 10;
+int seq = 1;
+
+/*
+  Базовый класс пакета
+
+  api - версия API (по умолчанию 10 для сокета)
+  cmd - от кого был прислан пакет (
+  0 - клиент (если отправляется серверу)
+  1 - сервер
+  3 - отправляется вместе с ошибкой)
+  seq - счёт пакетов (начинается с 1)
+  opcode - показывает, для чего отправляется пакет (подробнее в /lib/core/protocol/opcode_map.dart)
+  payload - содержимое пакета (отправляется с сервера ввиде msgpack)
+*/
+class Packet {
+  int api;
+  int cmd;
+  int seq;
+  int opcode;
+  Map<dynamic, dynamic> payload;
+
+  Packet({
+    this.api = 10,
+    this.cmd = 0,
+    this.seq = 1,
+    this.opcode = 0,
+    this.payload = const {},
+  });
+
+  /// Выводит пакет в консоль
+  void printPacket() {
+    print(
+      "Api: $api\nCmd: $cmd\nSeq: $seq\nOPCode: $opcode\nPayload: $payload",
+    );
+  }
+}
+
+/// Функция запаковки пакета
+/// Принимает только opcode и payload, так как api и cmd
+/// константы (10 и 0 соответственно), а seq считается менеджером сокета
+/// Возращает запакованный пакет
+Uint8List packPacket(int opcode, Map<dynamic, dynamic> payload) {
+  // Объяснение каждой переменной смотри в классе Packet
+
+  final apiVerB = Uint8List(1)..[0] = apiVersion;
+  final cmdB = Uint8List(1)..[0] = 0;
+  final seqB = Uint8List(2)..buffer.asByteData().setUint16(0, seq, Endian.big);
+  final opcodeB = Uint8List(2)
+    ..buffer.asByteData().setUint16(0, opcode, Endian.big);
+
+  // Перед получением длины пакуем в msgpack
+  final payloadBytes = msgpack.serialize(payload);
+  final payloadLen = payloadBytes.length & 0xFFFFFF;
+
+  final payloadLenB = Uint8List(4)
+    ..buffer.asByteData().setUint32(0, payloadLen, Endian.big);
+
+  return Uint8List.fromList(
+    apiVerB + cmdB + seqB + opcodeB + payloadLenB + payloadBytes,
+  );
+}
+
+/// Функция распаковки пакета
+/// Принимает байты пакета, которые отправляет сервер
+/// Возращает Packet
+Packet unpackPacket(Uint8List packet) {
+  // Для удобства расшифровки пакета переводим в ByteData
+  ByteData packetData = ByteData.view(packet.buffer);
+
+  // Объяснение каждой переменной смотри в классе Packet
+
+  // API версия и cmd представляют из себя 8 битные числа
+  var apiVer = packetData.getUint8(0) & 0xFF;
+  var cmd = packetData.getUint8(1) & 0xFF;
+
+  // Sequence и OPCode представляют из себя 16 битные числа
+  var seq = packetData.getUint16(2) & 0xFFFF;
+  var opcode = packetData.getUint16(4) & 0xFFFF;
+
+  // После базовых переменных идет длина пакета, является 32 битным числом
+  var packedLen = packetData.getUint32(6);
+
+  // Compression flag показывает, сжат ли payload
+  var compFlag = packedLen >> 24;
+
+  // Длина payload'а
+  var payloadLength = packedLen & 0xFFFFFF;
+
+  // Байты payload'а, могут быть сжаты LZ4
+  var payloadBytes = packet.buffer.asUint8List(10, payloadLength);
+
+  var payload = {};
+
+  // Если payload пустой, ничего не делаем (так может быть при получении пинга)
+  if (payloadBytes.buffer.lengthInBytes > 0) {
+    // Если пакет сжат, используем LZ4
+    if (compFlag != 0) {
+      try {
+        final decompressedBytes = lz4Decompress(
+          payloadBytes,
+          decompressedSize: 99999,
+        );
+
+        payloadBytes = decompressedBytes;
+      } catch (e) {
+        print("Ошибка при декомпрессировании: $e");
+      }
+    }
+
+    // Пробуем десериализовать msgpack
+    try {
+      payload = msgpack.deserialize(payloadBytes);
+    } catch (e) {
+      print("Ошибка при десериализации msgpack: $e");
+    }
+  }
+
+  // Собираем целый пакет и возращаем его
+  final fullPacket = Packet(
+    api: apiVer,
+    cmd: cmd,
+    seq: seq,
+    opcode: opcode,
+    payload: payload,
+  );
+
+  return fullPacket;
+}

lib/main.dart

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+import 'package:flutter/material.dart';
+
+void main() {
+  runApp(const MyApp());
+}
+
+class MyApp extends StatelessWidget {
+  const MyApp({super.key});
+
+  // This widget is the root of your application.
+  @override
+  Widget build(BuildContext context) {
+    return MaterialApp(
+      title: 'Flutter Demo',
+      theme: ThemeData(
+        // This is the theme of your application.
+        //
+        // TRY THIS: Try running your application with "flutter run". You'll see
+        // the application has a purple toolbar. Then, without quitting the app,
+        // try changing the seedColor in the colorScheme below to Colors.green
+        // and then invoke "hot reload" (save your changes or press the "hot
+        // reload" button in a Flutter-supported IDE, or press "r" if you used
+        // the command line to start the app).
+        //
+        // Notice that the counter didn't reset back to zero; the application
+        // state is not lost during the reload. To reset the state, use hot
+        // restart instead.
+        //
+        // This works for code too, not just values: Most code changes can be
+        // tested with just a hot reload.
+        colorScheme: .fromSeed(seedColor: Colors.deepPurple),
+      ),
+      home: const MyHomePage(title: 'Flutter Demo Home Page'),
+    );
+  }
+}
+
+class MyHomePage extends StatefulWidget {
+  const MyHomePage({super.key, required this.title});
+
+  // This widget is the home page of your application. It is stateful, meaning
+  // that it has a State object (defined below) that contains fields that affect
+  // how it looks.
+
+  // This class is the configuration for the state. It holds the values (in this
+  // case the title) provided by the parent (in this case the App widget) and
+  // used by the build method of the State. Fields in a Widget subclass are
+  // always marked "final".
+
+  final String title;
+
+  @override
+  State<MyHomePage> createState() => _MyHomePageState();
+}
+
+class _MyHomePageState extends State<MyHomePage> {
+  int _counter = 0;
+
+  void _incrementCounter() {
+    setState(() {
+      // This call to setState tells the Flutter framework that something has
+      // changed in this State, which causes it to rerun the build method below
+      // so that the display can reflect the updated values. If we changed
+      // _counter without calling setState(), then the build method would not be
+      // called again, and so nothing would appear to happen.
+      _counter++;
+    });
+  }
+
+  @override
+  Widget build(BuildContext context) {
+    // This method is rerun every time setState is called, for instance as done
+    // by the _incrementCounter method above.
+    //
+    // The Flutter framework has been optimized to make rerunning build methods
+    // fast, so that you can just rebuild anything that needs updating rather
+    // than having to individually change instances of widgets.
+    return Scaffold(
+      appBar: AppBar(
+        // TRY THIS: Try changing the color here to a specific color (to
+        // Colors.amber, perhaps?) and trigger a hot reload to see the AppBar
+        // change color while the other colors stay the same.
+        backgroundColor: Theme.of(context).colorScheme.inversePrimary,
+        // Here we take the value from the MyHomePage object that was created by
+        // the App.build method, and use it to set our appbar title.
+        title: Text(widget.title),
+      ),
+      body: Center(
+        // Center is a layout widget. It takes a single child and positions it
+        // in the middle of the parent.
+        child: Column(
+          // Column is also a layout widget. It takes a list of children and
+          // arranges them vertically. By default, it sizes itself to fit its
+          // children horizontally, and tries to be as tall as its parent.
+          //
+          // Column has various properties to control how it sizes itself and
+          // how it positions its children. Here we use mainAxisAlignment to
+          // center the children vertically; the main axis here is the vertical
+          // axis because Columns are vertical (the cross axis would be
+          // horizontal).
+          //
+          // TRY THIS: Invoke "debug painting" (choose the "Toggle Debug Paint"
+          // action in the IDE, or press "p" in the console), to see the
+          // wireframe for each widget.
+          mainAxisAlignment: .center,
+          children: [
+            const Text('You have pushed the button this many times:'),
+            Text(
+              '$_counter',
+              style: Theme.of(context).textTheme.headlineMedium,
+            ),
+          ],
+        ),
+      ),
+      floatingActionButton: FloatingActionButton(
+        onPressed: _incrementCounter,
+        tooltip: 'Increment',
+        child: const Icon(Icons.add),
+      ),
+    );
+  }
+}