playlist retry-exhaustion handling

internal/playback/playlist_readiness.go

@@ -89,7 +89,8 @@ func (c *PlaylistReadinessCoordinator) Run(ctx context.Context) error {
 	ticker := c.newTicker(c.interval)
 	defer ticker.Stop()
 
-	var emittedRevision uint64
+	var emittedReadyRevision uint64
+	var emittedFailedRevision uint64
 	for {
 		select {
 		case <-ctx.Done():
@@ -99,11 +100,7 @@ func (c *PlaylistReadinessCoordinator) Run(ctx context.Context) error {
 			playlistSnapshot, ok := c.playlist.Snapshot()
 			if !ok ||
 				!playlistSnapshot.State.HasSelection ||
-				playlistSnapshot.Revision == 0 ||
-				playlistSnapshot.Entry.Duration <= 0 ||
-				playlistSnapshot.Timing.Started ||
-				playlistSnapshot.Timing.Paused ||
-				playlistSnapshot.Revision == emittedRevision {
+				playlistSnapshot.Revision == 0 {
 				continue
 			}
 
@@ -114,7 +111,30 @@ func (c *PlaylistReadinessCoordinator) Run(ctx context.Context) error {
 			) {
 				continue
 			}
-			if !IsSessionPlaying(sessionSnapshot, c.statuses.SnapshotAll()) {
+			statuses := c.statuses.SnapshotAll()
+			if IsSessionFailed(sessionSnapshot, statuses) {
+				if playlistSnapshot.Revision == emittedFailedRevision {
+					continue
+				}
+				failed := PlaylistEvent{
+					Revision: playlistSnapshot.Revision,
+					Kind:     PlaylistEventFailed,
+				}
+				select {
+				case <-ctx.Done():
+					return ctx.Err()
+				case c.output <- failed:
+					emittedFailedRevision = playlistSnapshot.Revision
+				}
+				continue
+			}
+			if playlistSnapshot.Entry.Duration <= 0 ||
+				playlistSnapshot.Timing.Started ||
+				playlistSnapshot.Timing.Paused ||
+				playlistSnapshot.Revision == emittedReadyRevision {
+				continue
+			}
+			if !IsSessionPlaying(sessionSnapshot, statuses) {
 				continue
 			}
 
@@ -123,7 +143,7 @@ func (c *PlaylistReadinessCoordinator) Run(ctx context.Context) error {
 			case <-ctx.Done():
 				return ctx.Err()
 			case c.output <- ready:
-				emittedRevision = playlistSnapshot.Revision
+				emittedReadyRevision = playlistSnapshot.Revision
 			}
 		}
 	}
@@ -193,6 +213,38 @@ func IsSessionPlaying(
 	}
 }
 
+func IsSessionFailed(
+	session SessionSnapshot,
+	statuses PlaybackStatusSnapshot,
+) bool {
+	if statuses.Generation != session.Generation {
+		return false
+	}
+
+	switch session.Plan.Topology {
+	case TopologyIndependent:
+		return (session.Plan.Video.Active && statusIsFailed(
+			statuses.Video, statuses.HasVideo, session.Generation, session.Plan.Video,
+		)) || (session.Plan.Audio.Active && statusIsFailed(
+			statuses.Audio, statuses.HasAudio, session.Generation, session.Plan.Audio,
+		))
+	case TopologySynchronized:
+		return statuses.HasSync &&
+			statuses.Sync.Generation == session.Generation &&
+			statuses.Sync.State == StateFailed &&
+			sameSyncSource(statuses.Sync.Pair, session.Plan.Sync)
+	default:
+		return false
+	}
+}
+
+func statusIsFailed(status Status, present bool, generation uint64, feed FeedConfig) bool {
+	return present &&
+		status.Generation == generation &&
+		status.State == StateFailed &&
+		sameFeedSource(status.Feed, feed)
+}
+
 func statusIsPlaying(
 	status Status,
 	present bool,