Consistent cancellation API across the library: S_OK = continue, S_FALSE = stop

8 files changed, 17 insertions, 6 deletions

diff --git a/Examples/WhisperDesktop/CaptureDlg.cpp b/Examples/WhisperDesktop/CaptureDlg.cpp
index 3c22078..0bd86f7 100644
--- a/Examples/WhisperDesktop/CaptureDlg.cpp
+++ b/Examples/WhisperDesktop/CaptureDlg.cpp
@@ -442,8 +442,8 @@ LRESULT CaptureDlg::onThreadStatus( UINT nMessage, WPARAM wParam, LPARAM lParam,
 
 HRESULT __stdcall CaptureDlg::cbCancel( void* pv ) noexcept
 {
-	CaptureDlg& dialog = *(CaptureDlg*)pv;
-	return dialog.threadState.stopRequested ? S_OK : S_FALSE;
+	const bool stopRequested = ( (CaptureDlg*)pv )->threadState.stopRequested;
+	return stopRequested ? S_FALSE : S_OK;
 }
 
 HRESULT __stdcall CaptureDlg::cbStatus( void* pv, Whisper::eCaptureStatus status ) noexcept
diff --git a/Whisper/API/MfStructs.h b/Whisper/API/MfStructs.h
index cd27659..39255de 100644
--- a/Whisper/API/MfStructs.h
+++ b/Whisper/API/MfStructs.h
@@ -40,8 +40,11 @@ namespace Whisper
 		Stalled = 0x80,
 	};
 
+	// Return S_OK to continue, or S_FALSE to stop the capture session
 	using pfnShouldCancel = HRESULT( __stdcall* )( void* pv ) noexcept;
+
 	using pfnCaptureStatus = HRESULT( __stdcall* )( void* pv, eCaptureStatus status ) noexcept;
+
 	struct sCaptureCallbacks
 	{
 		pfnShouldCancel shouldCancel;
diff --git a/Whisper/API/sFullParams.h b/Whisper/API/sFullParams.h
index 0a1d352..42d48a4 100644
--- a/Whisper/API/sFullParams.h
+++ b/Whisper/API/sFullParams.h
@@ -14,6 +14,8 @@ namespace Whisper
 	};
 
 	using pfnNewSegment = HRESULT( __cdecl* )( iContext* ctx, uint32_t n_new, void* user_data ) noexcept;
+
+	// Return S_OK to proceed, or S_FALSE to stop the process and return S_OK from runFull / runStreamed method
 	using pfnEncoderBegin = HRESULT( __cdecl* )( iContext* ctx, void* user_data ) noexcept;
 
 	enum struct eFullParamsFlags : uint32_t
diff --git a/Whisper/API/sLoadModelCallbacks.h b/Whisper/API/sLoadModelCallbacks.h
index f5248c6..8f274c6 100644
--- a/Whisper/API/sLoadModelCallbacks.h
+++ b/Whisper/API/sLoadModelCallbacks.h
@@ -3,6 +3,7 @@
 namespace Whisper
 {
 	using pfnLoadProgress = HRESULT( __stdcall* )( double val, void* pv ) noexcept;
+	// Return S_OK to continue, or S_FALSE to fail with "The operation was canceled by the user" status code
 	using pfnCancel = HRESULT( __stdcall* )( void* pv ) noexcept;
 	
 	struct sLoadModelCallbacks
diff --git a/Whisper/Whisper/ContextImpl.capture.cpp b/Whisper/Whisper/ContextImpl.capture.cpp
index 617c1f3..0062c2a 100644
--- a/Whisper/Whisper/ContextImpl.capture.cpp
+++ b/Whisper/Whisper/ContextImpl.capture.cpp
@@ -171,7 +171,7 @@ namespace
 		HRESULT checkCancel() noexcept
 		{
 			if( nullptr == callbacks.shouldCancel )
-				return S_FALSE;
+				return S_OK;
 			return callbacks.shouldCancel( callbacks.pv );
 		}
 
@@ -415,7 +415,7 @@ HRESULT COMLIGHTCALL ContextImpl::runCapture( const sFullParams& params, const s
 	{
 		HRESULT hr = capture.checkCancel();
 		CHECK( hr );
-		if( hr == S_OK )
+		if( hr != S_OK )
 			return S_OK;
 		CHECK( capture.run() );
 	}
diff --git a/Whisper/Whisper/ContextImpl.cpp b/Whisper/Whisper/ContextImpl.cpp
index 175af74..59d644b 100644
--- a/Whisper/Whisper/ContextImpl.cpp
+++ b/Whisper/Whisper/ContextImpl.cpp
@@ -257,6 +257,7 @@ HRESULT COMLIGHTCALL ContextImpl::runFullImpl( const sFullParams& params, const
 	int seek = seek_start;
 	// Start measuring "Run" profiler value, both CPU and GPU times
 	auto prof = context.completeProfiler();
+	bool stoppedPrematurely = false;
 	while( true )
 	{
 		if( nullptr != progress.pfn )
@@ -278,7 +279,10 @@ HRESULT COMLIGHTCALL ContextImpl::runFullImpl( const sFullParams& params, const
 			if( FAILED( hr ) )
 				return hr;
 			if( hr != S_OK )
+			{
+				stoppedPrematurely = true;
 				break;
+			}
 		}
 
 		// encode audio features starting at offset seek
@@ -511,7 +515,7 @@ HRESULT COMLIGHTCALL ContextImpl::runFullImpl( const sFullParams& params, const
 		seek += seek_delta;
 	}
 
-	if( nullptr != progress.pfn )
+	if( nullptr != progress.pfn && !stoppedPrematurely )
 	{
 		auto cb = profiler.cpuBlock( eCpuBlock::Callbacks );
 		CHECK( progress.pfn( 1.0, this, progress.pv ) );
diff --git a/WhisperNet/CaptureCallbacks.cs b/WhisperNet/CaptureCallbacks.cs
index 26013f9..f2528e4 100644
--- a/WhisperNet/CaptureCallbacks.cs
+++ b/WhisperNet/CaptureCallbacks.cs
@@ -19,7 +19,7 @@ namespace Whisper
 			{
 				try
 				{
-					return shouldCancel( sender ) ? S_OK : S_FALSE;
+					return shouldCancel( sender ) ? S_FALSE : S_OK;
 				}
 				catch( Exception ex )
 				{
diff --git a/WhisperNet/Internal/sCaptureCallbacks.cs b/WhisperNet/Internal/sCaptureCallbacks.cs
index 483c2f2..0865a5a 100644
--- a/WhisperNet/Internal/sCaptureCallbacks.cs
+++ b/WhisperNet/Internal/sCaptureCallbacks.cs
@@ -3,6 +3,7 @@
 namespace Whisper.Internal
 {
 	/// <summary>Unmanaged code calls this to check for cancellation</summary>
+	/// <remarks>Return 0 to proceed, or 1 to stop the process and return from Context.runFull method</remarks>
 	[UnmanagedFunctionPointer( CallingConvention.StdCall )]
 	public delegate int pfnShouldCancel( IntPtr pv );