fix: block playout build loop (#2957)

CHANGELOG.md

@@ -29,11 +29,12 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/).
   - Content that can never play was still counted as waiting to play, so that never happened and the order stayed the same forever
   - This was caused by specials (season 0), which are skipped by `Season, Episode` order; marathons grouped by show or season use that order unless `Marathon Shuffle Items` is enabled
   - Affected playouts also became slower to build the longer they ran
-- Fix shuffled playlists and marathon groups changing order when a playout is rebuilt
+- Fix shuffled playlists and marathon groups changing order when a playout is rebuilt (continued or refreshed)
   - Existing playlists and marathons will change order once after updating
 - Fix playlists used as filler skipping content
   - When something doesn't fit, ETV puts the filler back where it was and tries again, but playlists were only partly put back
   - This could skip playlist content, and could cause the next playout build to resume in the wrong place
+- Fix case where block playouts would occasionally get stuck building forever
 - Fix green line sometimes seen with NVIDIA and AMD/VAAPI encoding
   - Both bugs were in ffmpeg, and ETV's patched ffmpeg 8.1.2 is required for the fixes
 

ErsatzTV.Core/Scheduling/BlockScheduling/BlockPlayoutBuilder.cs

@@ -217,8 +217,13 @@ public class BlockPlayoutBuilder(
                         if (effectiveBlock.Block.StopScheduling is BlockStopScheduling.BeforeDurationEnd &&
                             itemDuration > blockDuration)
                         {
-                            foreach (TimeSpan minimumDuration in enumerator.MinimumDuration)
+                            // enumerator.MinimumDuration is none for images and remote streams, which
-                            {
+                            // would skip forever, so use the same duration source as the check above
+                            TimeSpan minimumDuration = collectionMediaItems[CollectionKey.ForBlockItem(blockItem)]
+                                .Map(i => i.GetDurationForPlayout())
+                                .OrderBy(identity)
+                                .Head();
+
                             if (minimumDuration > blockDuration)
                             {
                                 Logger.LogError(
@@ -227,11 +232,6 @@ public class BlockPlayoutBuilder(
                                     blockDuration);
 
                                 done = true;
-                                }
-                            }
-
-                            if (done)
-                            {
                                 break;
                             }
 

ErsatzTV.Core/Scheduling/BlockScheduling/BlockPlayoutFillerBuilder.cs

@@ -34,13 +34,19 @@ public class BlockPlayoutFillerBuilder(
         var allItems = result.AddedItems.ToList();
         var removeBefore = await result.RemoveBefore.IfNoneAsync(DateTimeOffset.MaxValue);
 
+        // existing items that finish before this are deleted from the database by this build,
+        // so they must not be treated as existing items here
+        DateTimeOffset deletedBefore = await result.RemoveBefore
+            .Map(rb => rb - referenceData.MaxPlayoutOffset)
+            .IfNoneAsync(DateTimeOffset.MinValue);
+
         if (mode is PlayoutBuildMode.Reset)
         {
             // remove all playout items with type filler
             // except block items that are hidden from the guide (guide mode)
             foreach (PlayoutItem item in filteredExistingItems)
             {
-                if (item.Finish < removeBefore)
+                if (item.FinishOffset < removeBefore)
                 {
                     continue;
                 }
@@ -90,6 +96,7 @@ public class BlockPlayoutFillerBuilder(
 
         allItems = referenceData.ExistingItems
             .Where(i => !result.ItemsToRemove.Contains(i.Id))
+            .Where(i => i.FinishOffset >= deletedBefore)
             .ToList();
         allItems.AddRange(result.AddedItems);
 
@@ -348,12 +355,24 @@ public class BlockPlayoutFillerBuilder(
 
                 DateTimeOffset current = start;
                 var pastTime = false;
-                while (current < finish)
+                while (current < finish && !cancellationToken.IsCancellationRequested)
                 {
                     foreach (MediaItem mediaItem in enumerator.Current)
                     {
                         TimeSpan itemDuration = mediaItem.GetDurationForPlayout();
 
+                        // without a duration this loop can never reach the end of the gap
+                        if (itemDuration <= TimeSpan.Zero)
+                        {
+                            logger.LogWarning(
+                                "Default filler item {Item} has no duration; will stop filling gap at {Time}",
+                                mediaItem.Id,
+                                current);
+
+                            pastTime = true;
+                            break;
+                        }
+
                         // add filler from deco to unscheduled period
                         var filler = new PlayoutItem
                         {