add session api endpoints (#1578)

CHANGELOG.md

@@ -29,6 +29,11 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/).
     - `Playout Templates` - templates to schedule using the specified criteria. Only one template will be selected each day
   - Much more to come on this feature as development continues
 - Show chapter markers in movie and episode media info
+- Add two new API endpoints for interacting with transcoding sessions (MPEG-TS and HLS Segmenter):
+  - GET `/api/sessions`
+    - Show brief info about all active sessions
+  - DELETE `/api/session/{channel-number}`
+    - Stop the session for the given channel number 
 
 ### Fixed
 - Fix error loading path replacements when using MySql

ErsatzTV.Application/Streaming/HlsSessionWorker.cs

@@ -39,6 +39,7 @@ public class HlsSessionWorker : IHlsSessionWorker
     private HlsSessionState _state;
     private Timer _timer;
     private DateTimeOffset _transcodedUntil;
+    private CancellationTokenSource _cancellationTokenSource;
 
     public HlsSessionWorker(
         IServiceScopeFactory serviceScopeFactory,
@@ -61,6 +62,21 @@ public class HlsSessionWorker : IHlsSessionWorker
 
     public DateTimeOffset PlaylistStart { get; private set; }
 
+    public async Task Cancel(CancellationToken cancellationToken)
+    {
+        _logger.LogInformation("API termination request for HLS session for channel {Channel}", _channelNumber);
+
+        await Slim.WaitAsync(cancellationToken);
+        try
+        {
+            await _cancellationTokenSource.CancelAsync();
+        }
+        finally
+        {
+            Slim.Release();
+        }
+    }
+
     public void Touch()
     {
         lock (_sync)
@@ -121,6 +137,8 @@ public class HlsSessionWorker : IHlsSessionWorker
 
     public void PlayoutUpdated() => _state = HlsSessionState.PlayoutUpdated;
     
+    public HlsSessionModel GetModel() => new(_channelNumber, _state.ToString(), _transcodedUntil, _lastAccess);
+
     void IDisposable.Dispose()
     {
         Dispose(true);
@@ -129,14 +147,14 @@ public class HlsSessionWorker : IHlsSessionWorker
 
     public async Task Run(string channelNumber, TimeSpan idleTimeout, CancellationToken incomingCancellationToken)
     {
-        var cts = CancellationTokenSource.CreateLinkedTokenSource(incomingCancellationToken);
+        _cancellationTokenSource = CancellationTokenSource.CreateLinkedTokenSource(incomingCancellationToken);
 
         [SuppressMessage("Usage", "VSTHRD100:Avoid async void methods")]
         async void Cancel(object o, ElapsedEventArgs e)
         {
             try
             {
-                await cts.CancelAsync();
+                await _cancellationTokenSource.CancelAsync();
             }
             catch (Exception)
             {
@@ -154,7 +172,7 @@ public class HlsSessionWorker : IHlsSessionWorker
                 _timer.Elapsed += Cancel;
             }
 
-            CancellationToken cancellationToken = cts.Token;
+            CancellationToken cancellationToken = _cancellationTokenSource.Token;
 
             _logger.LogInformation("Starting HLS session for channel {Channel}", channelNumber);
 
@@ -495,7 +513,10 @@ public class HlsSessionWorker : IHlsSessionWorker
         // delete old segments
         var allSegments = Directory.GetFiles(
                 Path.Combine(FileSystemLayout.TranscodeFolder, _channelNumber),
-                "live*.ts")
+                "live*.ts").Append(
+                Directory.GetFiles(
+                    Path.Combine(FileSystemLayout.TranscodeFolder, _channelNumber),
+                    "live*.mp4"))
             .Map(
                 file =>
                 {

ErsatzTV.Core/FFmpeg/HlsSessionModel.cs

@@ -0,0 +1,7 @@
+namespace ErsatzTV.Core.FFmpeg;
+
+public record HlsSessionModel(
+    string ChannelNumber,
+    string State,
+    DateTimeOffset TranscodedUntil,
+    DateTimeOffset LastAccess);

ErsatzTV.Core/Interfaces/FFmpeg/IHlsSessionWorker.cs

@@ -4,7 +4,9 @@ namespace ErsatzTV.Core.Interfaces.FFmpeg;
 
 public interface IHlsSessionWorker : IDisposable
 {
+    Task Cancel(CancellationToken cancellationToken);
     void Touch();
     Task<Option<TrimPlaylistResult>> TrimPlaylist(DateTimeOffset filterBefore, CancellationToken cancellationToken);
     void PlayoutUpdated();
+    HlsSessionModel GetModel();
 }

ErsatzTV/Controllers/Api/SessionController.cs

@@ -0,0 +1,27 @@
+using ErsatzTV.Core.FFmpeg;
+using ErsatzTV.Core.Interfaces.FFmpeg;
+using Microsoft.AspNetCore.Mvc;
+
+namespace ErsatzTV.Controllers.Api;
+
+[ApiController]
+public class SessionController(IFFmpegSegmenterService ffmpegSegmenterService)
+{
+    [HttpGet("api/sessions")]
+    public List<HlsSessionModel> GetSessions()
+    {
+        return ffmpegSegmenterService.SessionWorkers.Values.Map(w => w.GetModel()).ToList();
+    }
+
+    [HttpDelete("api/session/{channelNumber}")]
+    public async Task<IActionResult> StopSession(string channelNumber, CancellationToken cancellationToken)
+    {
+        if (ffmpegSegmenterService.SessionWorkers.TryGetValue(channelNumber, out IHlsSessionWorker worker))
+        {
+            await worker.Cancel(cancellationToken);
+            return new NoContentResult();
+        }
+
+        return new NotFoundResult();
+    }
+}