fix(moq-mux): keep catalog Consumer Clone + stable FramedFormat discriminants (#1661)

Co-authored-by: Claude <noreply@anthropic.com>

Author: kixelated

Cargo.lock

@@ -224,6 +224,20 @@ pub struct Consumer<T> {
 	_marker: PhantomData<fn() -> T>,
 }
 
+// Manual impl so cloning doesn't require `T: Clone`; `T` only lives in PhantomData.
+// Cloned readers inherit the current reconstruction state, then advance in parallel.
+impl<T> Clone for Consumer<T> {
+	fn clone(&self) -> Self {
+		Self {
+			track: self.track.clone(),
+			group: self.group.clone(),
+			current: self.current.clone(),
+			frames_read: self.frames_read,
+			_marker: PhantomData,
+		}
+	}
+}
+
 impl<T: DeserializeOwned> Consumer<T> {
 	/// Create a consumer reading from the given track subscriber.
 	pub fn new(track: moq_net::TrackConsumer) -> Self {
@@ -462,4 +476,36 @@ mod test {
 		}
 		assert_eq!(last.unwrap(), json!({ "a": 3 }));
 	}
+
+	#[test]
+	fn cloned_consumer_reconstructs_independently() {
+		// Deltas share one group, so a clone taken mid-group carries in-progress reconstruction state.
+		let config = Config {
+			delta_ratio: Some(100.0),
+		};
+		let (mut producer, track) = producer(config);
+		let mut consumer = Consumer::<Value>::new(track);
+		let waiter = kio::Waiter::noop();
+
+		producer.update(&json!({ "a": 1, "b": 1 })).unwrap(); // snapshot, group 0
+		match consumer.poll_next(&waiter) {
+			Poll::Ready(Ok(Some(value))) => assert_eq!(value, json!({ "a": 1, "b": 1 })),
+			other => panic!("expected snapshot, got {other:?}"),
+		}
+
+		// Clone after the snapshot: the copy inherits `current`/`frames_read` and an independent cursor.
+		let mut clone = consumer.clone();
+
+		producer.update(&json!({ "a": 1, "b": 2 })).unwrap(); // delta in group 0
+		producer.finish().unwrap();
+
+		// Each consumer applies the delta on top of its own reconstruction state.
+		let expected = json!({ "a": 1, "b": 2 });
+		for consumer in [&mut consumer, &mut clone] {
+			match consumer.poll_next(&waiter) {
+				Poll::Ready(Ok(Some(value))) => assert_eq!(value, expected),
+				other => panic!("expected delta, got {other:?}"),
+			}
+		}
+	}
 }

rs/moq-json/src/lib.rs

@@ -5,7 +5,7 @@ authors = ["Luke Curley <kixelated@gmail.com>"]
 repository = "https://github.com/moq-dev/moq"
 license = "MIT OR Apache-2.0"
 
-version = "0.5.3"
+version = "0.5.4"
 edition = "2024"
 rust-version.workspace = true
 

rs/moq-mux/Cargo.toml

@@ -8,6 +8,7 @@ use crate::Result;
 ///
 /// This wraps a [`moq_json::Consumer`], reconstructing the JSON catalog from the latest
 /// group's snapshot (plus any future deltas) to discover available audio and video tracks.
+#[derive(Clone)]
 pub struct Consumer {
 	inner: moq_json::Consumer<Catalog>,
 }

rs/moq-mux/src/catalog/hang/consumer.rs

@@ -28,10 +28,6 @@ pub enum FramedFormat {
 	Hev1,
 	/// AV1 with inline sequence headers
 	Av01,
-	/// VP8 (one frame per buffer; not self-delimiting).
-	Vp8,
-	/// VP9 (one frame per buffer; not self-delimiting).
-	Vp9,
 	/// Raw AAC frames (not ADTS).
 	Aac,
 	/// Raw Opus frames (not Ogg).
@@ -40,6 +36,12 @@ pub enum FramedFormat {
 	Mkv,
 	/// MPEG-TS (transport stream) container.
 	Ts,
+	// New variants go at the end: this enum has no repr, so inserting in the
+	// middle would shift the implicit discriminants of everything after it.
+	/// VP8 (one frame per buffer; not self-delimiting).
+	Vp8,
+	/// VP9 (one frame per buffer; not self-delimiting).
+	Vp9,
 }
 
 impl FromStr for FramedFormat {
@@ -52,12 +54,12 @@ impl FromStr for FramedFormat {
 			"hev1" => Ok(FramedFormat::Hev1),
 			"fmp4" | "cmaf" => Ok(FramedFormat::Fmp4),
 			"av01" | "av1" | "av1c" | "av1C" => Ok(FramedFormat::Av01),
-			"vp8" | "vp08" => Ok(FramedFormat::Vp8),
-			"vp9" | "vp09" => Ok(FramedFormat::Vp9),
 			"aac" => Ok(FramedFormat::Aac),
 			"opus" => Ok(FramedFormat::Opus),
 			"mkv" | "webm" | "matroska" => Ok(FramedFormat::Mkv),
 			"ts" | "mpegts" | "mpeg2ts" | "m2ts" => Ok(FramedFormat::Ts),
+			"vp8" | "vp08" => Ok(FramedFormat::Vp8),
+			"vp9" | "vp09" => Ok(FramedFormat::Vp9),
 			_ => Err(Error::UnknownFormat(s.to_string())),
 		}
 	}
@@ -71,12 +73,12 @@ impl fmt::Display for FramedFormat {
 			FramedFormat::Fmp4 => write!(f, "fmp4"),
 			FramedFormat::Hev1 => write!(f, "hev1"),
 			FramedFormat::Av01 => write!(f, "av01"),
-			FramedFormat::Vp8 => write!(f, "vp8"),
-			FramedFormat::Vp9 => write!(f, "vp9"),
 			FramedFormat::Aac => write!(f, "aac"),
 			FramedFormat::Opus => write!(f, "opus"),
 			FramedFormat::Mkv => write!(f, "mkv"),
 			FramedFormat::Ts => write!(f, "ts"),
+			FramedFormat::Vp8 => write!(f, "vp8"),
+			FramedFormat::Vp9 => write!(f, "vp9"),
 		}
 	}
 }