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 +1,62 @@
+using System.Threading;
+using System.Threading.Tasks;
+
+namespace MediaBrowser.Controller.MediaEncoding;
+
+/// <summary>
+/// Provides a durable store for HLS transcoding session state, enabling
+/// HA recovery and lease-based ownership between pods.
+/// </summary>
+public interface ITranscodeSessionStore
+{
+    /// <summary>
+    /// Attempts to retrieve a transcoding session by its play session identifier.
+    /// </summary>
+    /// <param name="playSessionId">The play session identifier.</param>
+    /// <param name="cancellationToken">A cancellation token.</param>
+    /// <returns>
+    /// The <see cref="TranscodeSession"/> if it exists and its lease has not expired;
+    /// otherwise <c>null</c>.
+    /// </returns>
+    Task<TranscodeSession?> TryGetAsync(string playSessionId, CancellationToken cancellationToken = default);
+
+    /// <summary>
+    /// Attempts to take over ownership of an existing session by claiming the lease for
+    /// <paramref name="claimingPod"/>. Takeover succeeds only when the session exists and
+    /// its current lease has already expired.
+    /// </summary>
+    /// <param name="playSessionId">The play session identifier.</param>
+    /// <param name="claimingPod">The name of the pod attempting to claim ownership.</param>
+    /// <param name="cancellationToken">A cancellation token.</param>
+    /// <returns>
+    /// <c>true</c> if the takeover succeeded (the claiming pod now holds the lease);
+    /// <c>false</c> if the session does not exist, its lease is still valid, or another
+    /// concurrent caller already claimed it.
+    /// </returns>
+    Task<bool> TryTakeoverAsync(string playSessionId, string claimingPod, CancellationToken cancellationToken = default);
+
+    /// <summary>
+    /// Persists a new or updated transcoding session.
+    /// </summary>
+    /// <param name="session">The session to store.</param>
+    /// <param name="cancellationToken">A cancellation token.</param>
+    /// <returns>A <see cref="Task"/> representing the asynchronous operation.</returns>
+    Task SetAsync(TranscodeSession session, CancellationToken cancellationToken = default);
+
+    /// <summary>
+    /// Renews the lease for an existing session, extending its
+    /// <see cref="TranscodeSession.LeaseExpiresUtc"/> by the store's configured lease duration.
+    /// </summary>
+    /// <param name="playSessionId">The play session identifier.</param>
+    /// <param name="cancellationToken">A cancellation token.</param>
+    /// <returns>A <see cref="Task"/> representing the asynchronous operation.</returns>
+    Task RenewLeaseAsync(string playSessionId, CancellationToken cancellationToken = default);
+
+    /// <summary>
+    /// Removes a transcoding session from the store.
+    /// </summary>
+    /// <param name="playSessionId">The play session identifier.</param>
+    /// <param name="cancellationToken">A cancellation token.</param>
+    /// <returns>A <see cref="Task"/> representing the asynchronous operation.</returns>
+    Task DeleteAsync(string playSessionId, CancellationToken cancellationToken = default);
+}