Implement Daybreak.API. Reorganize FocusView components (#995)

Daybreak.API/WebSockets/UpdateWebSocketRoute.cs

@@ -0,0 +1,46 @@
+using Net.Sdk.Web.Websockets;
+using System.Buffers;
+using System.Net.WebSockets;
+
+namespace Daybreak.API.WebSockets;
+
+public abstract class UpdateWebSocketRoute
+    : WebSocketRouteBase
+{
+    private readonly byte[] sharedBuffer;
+    private readonly ArraySegment<byte> packetBuffer;
+    private int sendingOperations = 0;
+
+    protected abstract int BufferSize { get; }
+
+    public UpdateWebSocketRoute()
+    {
+        this.sharedBuffer = ArrayPool<byte>.Shared.Rent(this.BufferSize);
+        this.packetBuffer = new ArraySegment<byte>(this.sharedBuffer);
+    }
+
+    public override Task SocketClosed()
+    {
+        ArrayPool<byte>.Shared.Return(this.sharedBuffer);
+        return base.SocketClosed();
+    }
+
+    public void SendUpdate(ReadOnlySpan<byte> state)
+    {
+        if (Interlocked.CompareExchange(ref this.sendingOperations, 1, 0) != 0)
+        {
+            return;
+        }
+
+        if (this.WebSocket is null)
+        {
+            this.sendingOperations = 0;
+            return;
+        }
+
+        state.CopyTo(this.packetBuffer);
+        var packet = this.packetBuffer.Slice(0, state.Length);
+        this.WebSocket?.SendAsync(packet, WebSocketMessageType.Binary, true, this.Context?.RequestAborted ?? CancellationToken.None)
+            .ContinueWith(_ => this.sendingOperations = 0);
+    }
+}