Optimizations for parsing and receiving OSC messages from recv.

VRCFaceTracking.Core/OSC/OSCMessage.cs

@@ -98,9 +98,20 @@ public OscMessage(byte[] bytes, int len, ref int messageIndex)
         _metaPtr = fti_osc.parse_osc(bytes, len, ref messageIndex);
         if (_metaPtr != IntPtr.Zero)
         {
-            _meta = Marshal.PtrToStructure<OscMessageMeta>(_metaPtr);
+            //var meta1 = Marshal.PtrToStructure<OscMessageMeta>(_metaPtr);
+            ParseToOscMessageMeta(_metaPtr);
         }
     }
+    private void ParseToOscMessageMeta(IntPtr ptr)
+    {
+        _meta.Address = Marshal.PtrToStringAnsi(Marshal.ReadIntPtr(ptr));
+        ptr += IntPtr.Size;
+
+        _meta.ValueLength = Marshal.ReadInt32(ptr);
+        ptr += IntPtr.Size;
+
+        _meta.Value = Marshal.ReadIntPtr(ptr);
+    }
 
     /// <summary>
     /// Encodes stored osc meta into raw bytes using fti_osc lib

VRCFaceTracking.Core/Services/OscRecvService.cs

@@ -16,7 +16,7 @@ public class OscRecvService : BackgroundService
     private readonly ILocalSettingsService _settingsService;
 
     private Socket _recvSocket;
-    private readonly byte[] _recvBuffer = new byte[4096];
+    private readonly byte[] _recvBuffer = new byte[64];
 
     private CancellationTokenSource _cts, _linkedToken;
     private CancellationToken _stoppingToken;
@@ -108,29 +108,34 @@ protected async override Task ExecuteAsync(CancellationToken stoppingToken)
                 continue;
             }
 
-            try
+            if (_recvSocket.Available > 0)
             {
-                var bytesReceived = await _recvSocket.ReceiveAsync(_recvBuffer, _linkedToken.Token);
-                var offset = 0;
-                var newMsg = await Task.Run(() => OscMessage.TryParseOsc(_recvBuffer, bytesReceived, ref offset), stoppingToken);
-                if (newMsg == null)
+                try
                 {
-                    continue;
-                }
+                    var bytesReceived = await _recvSocket.ReceiveAsync(_recvBuffer, SocketFlags.None, _linkedToken.Token);
+                    var offset = 0;
+                    var newMsg = OscMessage.TryParseOsc(_recvBuffer, bytesReceived, ref offset);
+                    if (newMsg == null)
+                    {
+                        continue;
+                    }
 
-                OnMessageReceived(newMsg);
-            }
-            catch (Exception e)
-            {
-                // We don't care about operation cancellations as they're intentional and carefully controlled
-                if (e.GetType() == typeof(OperationCanceledException))
+                    OnMessageReceived(newMsg);
+                }
+                catch (Exception e)
                 {
-                    continue;
+                    // We don't care about operation cancellations as they're intentional and carefully controlled
+                    if (e.GetType() == typeof(OperationCanceledException))
+                    {
+                        continue;
+                    }
+
+                    _logger.LogError("Error encountered in OSC Receive thread: {e}", e);
+                    SentrySdk.CaptureException(e, scope => scope.SetExtra("recvBuffer", _recvBuffer));
                 }
-
-                _logger.LogError("Error encountered in OSC Receive thread: {e}", e);
-                SentrySdk.CaptureException(e, scope => scope.SetExtra("recvBuffer", _recvBuffer));
             }
+            else
+                await Task.Delay(100, _linkedToken.Token);
         }
     }
 }