review comments

Author: Mikachu

src/output/Filtered.cxx

@@ -192,7 +192,7 @@ FilteredAudioOutput::Cancel() noexcept
 void
 FilteredAudioOutput::BeginPause() noexcept
 {
-	if (!output->SupportsPauseWithoutCancel())
+	if (!output->SupportsHardwarePause())
 		Cancel();
 }
 

src/output/Interface.hxx

@@ -40,14 +40,24 @@ public:
 		return flags & FLAG_PAUSE;
 	}
 
-	virtual bool SupportsPauseWithoutCancel() const noexcept {
-		return false;
-	}
-
 	bool GetNeedFullyDefinedAudioFormat() const noexcept {
 		return flags & FLAG_NEED_FULLY_DEFINED_AUDIO_FORMAT;
 	}
 
+	/**
+	 * Returns true if this plugin can pause playback without first
+	 * discarding buffered audio via Cancel().  When this returns true,
+	 * #FilteredAudioOutput::BeginPause() will skip the Cancel() call,
+	 * allowing the plugin to preserve its hardware buffer across a pause
+	 * and resume it intact when Play() is next called.
+	 *
+	 * Plugins that return true must handle buffer cleanup if
+	 * Cancel() is called while paused (e.g. on stop or seek).
+	 */
+	virtual bool SupportsHardwarePause() const noexcept {
+		return false;
+	}
+
 	/**
 	 * Returns a map of runtime attributes.
 	 *

src/output/plugins/AlsaOutputPlugin.cxx

@@ -400,7 +400,7 @@ class AlsaOutput final
 	Event::Duration PrepareSockets() noexcept override;
 	void DispatchSockets() noexcept override;
 
-	bool SupportsPauseWithoutCancel() const noexcept override {
+	bool SupportsHardwarePause() const noexcept override {
 		return !close_on_pause && hw_can_pause;
 	}
 
@@ -1103,7 +1103,6 @@ AlsaOutput::CancelInternal() noexcept
 	ring_buffer.Clear();
 
 	active = false;
-	paused = false;
 	waiting = false;
 
 	UnregisterSockets();