1 files changed, 64 insertions, 0 deletions
diff --git a/WhisperNet/Internal/sLoadModelCallbacks.cs b/WhisperNet/Internal/sLoadModelCallbacks.cs
new file mode 100644
index 0000000..07f5199
--- /dev/null
+++ b/WhisperNet/Internal/sLoadModelCallbacks.cs
@@ -0,0 +1,64 @@
+using System.Runtime.InteropServices;
+
+namespace Whisper.Internal
+{
+	/// <summary>Function pointer to report model loading progress</summary>
+	[UnmanagedFunctionPointer( CallingConvention.StdCall )]
+	delegate int pfnLoadProgress( double progress, IntPtr pv );
+
+	/// <summary>Function pointer to implement cooperative cancellation</summary>
+	[UnmanagedFunctionPointer( CallingConvention.StdCall )]
+	delegate int pfnCancel( IntPtr pv );
+
+	/// <summary>Callback functions for loading models</summary>
+	public struct sLoadModelCallbacks
+	{
+		/// <summary>Function pointer to report model loading progress</summary>
+		[MarshalAs( UnmanagedType.FunctionPtr )]
+		pfnLoadProgress? progress;
+
+		/// <summary>Function pointer to implement cooperative cancellation</summary>
+		[MarshalAs( UnmanagedType.FunctionPtr )]
+		pfnCancel? cancel;
+
+		// Not needed in C#, delegates can capture things
+		IntPtr pv;
+
+		/// <summary>Wrap idiomatic C# things into these low-level C callbacks</summary>
+		internal sLoadModelCallbacks( CancellationToken cancelToken, Action<double>? pfnProgress )
+		{
+			if( cancelToken != CancellationToken.None )
+			{
+				cancel = delegate ( IntPtr pv )
+				{
+					if( cancelToken.IsCancellationRequested )
+						return 1;   // S_FALSE
+					return 0;   // S_OK
+				};
+			}
+			else
+				cancel = null;
+
+			if( null != pfnProgress )
+			{
+				progress = delegate ( double val, IntPtr pv )
+				{
+					try
+					{
+						pfnProgress( val );
+						return 0;   // S_OK
+					}
+					catch( Exception ex )
+					{
+						NativeLogger.captureException( ex );
+						return ex.HResult;
+					}
+				};
+			}
+			else
+				progress = null;
+
+			pv = IntPtr.Zero;
+		}
+	}
+}
+\ No newline at end of file