chore: initialize standalone UPM package

2026-08-26 02:50:34 +08:00
commit 8eaaa3040a
139 changed files with 9309 additions and 0 deletions
@@ -0,0 +1,114 @@
+using System;
+using System.Buffers.Binary;
+
+namespace ShrinkNetwork
+{
+    internal enum ShrinkKcpEnvelopeKind : byte
+    {
+        ConnectRequest = 1,
+        ConnectAccept = 2,
+        Disconnect = 3,
+        Data = 4
+    }
+
+    internal static class ShrinkKcpTransportProtocol
+    {
+        private const int KindSize = 1;
+        private const int ConversationSize = 4;
+        private const int NonceSize = 8;
+
+        public static byte[] CreateConnectRequest(long nonce, uint requestedConversationId)
+        {
+            var buffer = new byte[KindSize + NonceSize + ConversationSize];
+            buffer[0] = (byte)ShrinkKcpEnvelopeKind.ConnectRequest;
+            BinaryPrimitives.WriteInt64LittleEndian(buffer.AsSpan(1, NonceSize), nonce);
+            BinaryPrimitives.WriteUInt32LittleEndian(buffer.AsSpan(1 + NonceSize, ConversationSize), requestedConversationId);
+            return buffer;
+        }
+
+        public static bool TryReadConnectRequest(byte[] datagram, out long nonce, out uint requestedConversationId)
+        {
+            nonce = default;
+            requestedConversationId = default;
+            if (datagram == null || datagram.Length != KindSize + NonceSize + ConversationSize)
+                return false;
+            if (datagram[0] != (byte)ShrinkKcpEnvelopeKind.ConnectRequest)
+                return false;
+
+            nonce = BinaryPrimitives.ReadInt64LittleEndian(datagram.AsSpan(1, NonceSize));
+            requestedConversationId = BinaryPrimitives.ReadUInt32LittleEndian(datagram.AsSpan(1 + NonceSize, ConversationSize));
+            return true;
+        }
+
+        public static byte[] CreateConnectAccept(long nonce, uint conversationId)
+        {
+            var buffer = new byte[KindSize + NonceSize + ConversationSize];
+            buffer[0] = (byte)ShrinkKcpEnvelopeKind.ConnectAccept;
+            BinaryPrimitives.WriteInt64LittleEndian(buffer.AsSpan(1, NonceSize), nonce);
+            BinaryPrimitives.WriteUInt32LittleEndian(buffer.AsSpan(1 + NonceSize, ConversationSize), conversationId);
+            return buffer;
+        }
+
+        public static bool TryReadConnectAccept(byte[] datagram, out long nonce, out uint conversationId)
+        {
+            nonce = default;
+            conversationId = default;
+            if (datagram == null || datagram.Length != KindSize + NonceSize + ConversationSize)
+                return false;
+            if (datagram[0] != (byte)ShrinkKcpEnvelopeKind.ConnectAccept)
+                return false;
+
+            nonce = BinaryPrimitives.ReadInt64LittleEndian(datagram.AsSpan(1, NonceSize));
+            conversationId = BinaryPrimitives.ReadUInt32LittleEndian(datagram.AsSpan(1 + NonceSize, ConversationSize));
+            return true;
+        }
+
+        public static byte[] CreateDisconnect(uint conversationId)
+        {
+            var buffer = new byte[KindSize + ConversationSize];
+            buffer[0] = (byte)ShrinkKcpEnvelopeKind.Disconnect;
+            BinaryPrimitives.WriteUInt32LittleEndian(buffer.AsSpan(1, ConversationSize), conversationId);
+            return buffer;
+        }
+
+        public static bool TryReadDisconnect(byte[] datagram, out uint conversationId)
+        {
+            conversationId = default;
+            if (datagram == null || datagram.Length != KindSize + ConversationSize)
+                return false;
+            if (datagram[0] != (byte)ShrinkKcpEnvelopeKind.Disconnect)
+                return false;
+
+            conversationId = BinaryPrimitives.ReadUInt32LittleEndian(datagram.AsSpan(1, ConversationSize));
+            return true;
+        }
+
+        public static byte[] CreateDataPacket(uint conversationId, byte[] payload)
+        {
+            payload ??= Array.Empty<byte>();
+
+            var buffer = new byte[KindSize + ConversationSize + payload.Length];
+            buffer[0] = (byte)ShrinkKcpEnvelopeKind.Data;
+            BinaryPrimitives.WriteUInt32LittleEndian(buffer.AsSpan(1, ConversationSize), conversationId);
+            if (payload.Length > 0)
+                Buffer.BlockCopy(payload, 0, buffer, KindSize + ConversationSize, payload.Length);
+            return buffer;
+        }
+
+        public static bool TryReadDataPacket(byte[] datagram, out uint conversationId, out int payloadOffset, out int payloadLength)
+        {
+            conversationId = default;
+            payloadOffset = default;
+            payloadLength = default;
+            if (datagram == null || datagram.Length < KindSize + ConversationSize)
+                return false;
+            if (datagram[0] != (byte)ShrinkKcpEnvelopeKind.Data)
+                return false;
+
+            conversationId = BinaryPrimitives.ReadUInt32LittleEndian(datagram.AsSpan(1, ConversationSize));
+            payloadOffset = KindSize + ConversationSize;
+            payloadLength = datagram.Length - payloadOffset;
+            return payloadLength >= 0;
+        }
+    }
+}