Add ITranscodeSessionStore interface and HA recovery unit tests (#19)

* Initial plan * Add ITranscodeSessionStore interface, TranscodeSession record, InMemoryTranscodeSessionStore fake, and HA unit tests" Co-authored-by: ZoltyMat <177592743+ZoltyMat@users.noreply.github.com> --------- Co-authored-by: copilot-swe-agent[bot] <198982749+Copilot@users.noreply.github.com> Co-authored-by: ZoltyMat <177592743+ZoltyMat@users.noreply.github.com>
2026-03-09 22:35:32 -04:00
parent cf5268c1e4
commit a187ab18b8
6 changed files with 756 additions and 0 deletions
@@ -0,0 +1,107 @@
+using System;
+using System.Collections.Generic;
+using System.Threading;
+using System.Threading.Tasks;
+using MediaBrowser.Controller.MediaEncoding;
+
+namespace Jellyfin.MediaEncoding.Tests.Fakes;
+
+/// <summary>
+/// Thread-safe, in-memory implementation of <see cref="ITranscodeSessionStore"/> for use in unit tests.
+/// </summary>
+public sealed class InMemoryTranscodeSessionStore : ITranscodeSessionStore
+{
+    /// <summary>
+    /// The duration added to <see cref="DateTime.UtcNow"/> when a lease is renewed or first claimed.
+    /// </summary>
+    public static readonly TimeSpan DefaultLeaseDuration = TimeSpan.FromSeconds(30);
+
+    private readonly Dictionary<string, TranscodeSession> _sessions = new(StringComparer.OrdinalIgnoreCase);
+    private readonly Lock _lock = new();
+
+    /// <inheritdoc />
+    public Task<TranscodeSession?> TryGetAsync(string playSessionId, CancellationToken cancellationToken = default)
+    {
+        lock (_lock)
+        {
+            if (_sessions.TryGetValue(playSessionId, out var session) && session.LeaseExpiresUtc > DateTime.UtcNow)
+            {
+                return Task.FromResult<TranscodeSession?>(Clone(session));
+            }
+
+            return Task.FromResult<TranscodeSession?>(null);
+        }
+    }
+
+    /// <inheritdoc />
+    public Task<bool> TryTakeoverAsync(string playSessionId, string claimingPod, CancellationToken cancellationToken = default)
+    {
+        lock (_lock)
+        {
+            if (!_sessions.TryGetValue(playSessionId, out var session))
+            {
+                return Task.FromResult(false);
+            }
+
+            if (session.LeaseExpiresUtc > DateTime.UtcNow)
+            {
+                // Another pod's lease is still valid – takeover not permitted.
+                return Task.FromResult(false);
+            }
+
+            // Lease has expired – claim it atomically.
+            session.OwnerPod = claimingPod;
+            session.LeaseExpiresUtc = DateTime.UtcNow.Add(DefaultLeaseDuration);
+            return Task.FromResult(true);
+        }
+    }
+
+    /// <inheritdoc />
+    public Task SetAsync(TranscodeSession session, CancellationToken cancellationToken = default)
+    {
+        lock (_lock)
+        {
+            _sessions[session.PlaySessionId] = session;
+        }
+
+        return Task.CompletedTask;
+    }
+
+    /// <inheritdoc />
+    public Task RenewLeaseAsync(string playSessionId, CancellationToken cancellationToken = default)
+    {
+        lock (_lock)
+        {
+            if (_sessions.TryGetValue(playSessionId, out var session))
+            {
+                session.LeaseExpiresUtc = DateTime.UtcNow.Add(DefaultLeaseDuration);
+            }
+        }
+
+        return Task.CompletedTask;
+    }
+
+    /// <inheritdoc />
+    public Task DeleteAsync(string playSessionId, CancellationToken cancellationToken = default)
+    {
+        lock (_lock)
+        {
+            _sessions.Remove(playSessionId);
+        }
+
+        return Task.CompletedTask;
+    }
+
+    private static TranscodeSession Clone(TranscodeSession source)
+        => new TranscodeSession
+        {
+            PlaySessionId = source.PlaySessionId,
+            OwnerPod = source.OwnerPod,
+            LeaseExpiresUtc = source.LeaseExpiresUtc,
+            ManifestPath = source.ManifestPath,
+            SegmentPathPrefix = source.SegmentPathPrefix,
+            MediaSourceId = source.MediaSourceId,
+            LastCompletedSegmentIndex = source.LastCompletedSegmentIndex,
+            LastDurablePlaybackOffset = source.LastDurablePlaybackOffset,
+        };
+}