#pragma warning restore VSTHRD103
private async Task <Unit> StartProcess(StartFFmpegSession request, CancellationToken cancellationToken)
{
TimeSpan idleTimeout = await _configElementRepository
.GetValue <int>(ConfigElementKey.FFmpegSegmenterTimeout)
.Map(maybeTimeout => maybeTimeout.Match(i => TimeSpan.FromSeconds(i), () => TimeSpan.FromMinutes(1)));
using IServiceScope scope = _serviceScopeFactory.CreateScope();
HlsSessionWorker worker = scope.ServiceProvider.GetRequiredService <HlsSessionWorker>();
_ffmpegSegmenterService.SessionWorkers.AddOrUpdate(request.ChannelNumber, _ => worker, (_, _) => worker);
// fire and forget worker
_ = worker.Run(request.ChannelNumber, idleTimeout, cancellationToken)
.ContinueWith(
_ => _ffmpegSegmenterService.SessionWorkers.TryRemove(
request.ChannelNumber,
out IHlsSessionWorker _),
TaskScheduler.Default);
string playlistFileName = Path.Combine(
FileSystemLayout.TranscodeFolder,
request.ChannelNumber,
"live.m3u8");
IConfigElementRepository repo = scope.ServiceProvider.GetRequiredService <IConfigElementRepository>();
int initialSegmentCount = await repo.GetValue <int>(ConfigElementKey.FFmpegInitialSegmentCount)
.Map(maybeCount => maybeCount.Match(identity, () => 1));
await WaitForPlaylistSegments(playlistFileName, initialSegmentCount, worker, cancellationToken);
return(Unit.Default);
}
private Task <Validation <BaseError, Unit> > FolderMustBeEmpty(StartFFmpegSession request)
{
string folder = Path.Combine(FileSystemLayout.TranscodeFolder, request.ChannelNumber);
_logger.LogDebug("Preparing transcode folder {Folder}", folder);
_localFileSystem.EnsureFolderExists(folder);
_localFileSystem.EmptyFolder(folder);
return(Task.FromResult <Validation <BaseError, Unit> >(Unit.Default));
}
private Task <Validation <BaseError, Unit> > SessionMustBeInactive(StartFFmpegSession request)
{
var result = Optional(_ffmpegSegmenterService.SessionWorkers.TryAdd(request.ChannelNumber, null))
.Where(success => success)
.Map(_ => Unit.Default)
.ToValidation <BaseError>(new ChannelSessionAlreadyActive());
if (result.IsFail && _ffmpegSegmenterService.SessionWorkers.TryGetValue(
request.ChannelNumber,
out IHlsSessionWorker worker))
{
worker?.Touch();
}
return(result.AsTask());
}
public Task <Either <BaseError, Unit> > Handle(StartFFmpegSession request, CancellationToken cancellationToken) =>
Validate(request)
.MapT(_ => StartProcess(request, cancellationToken))
// this weirdness is needed to maintain the error type (.ToEitherAsync() just gives BaseError)
#pragma warning disable VSTHRD103
.Bind(v => v.ToEither().MapLeft(seq => seq.Head()).MapAsync <BaseError, Task <Unit>, Unit>(identity));
private Task <Validation <BaseError, Unit> > Validate(StartFFmpegSession request) => SessionMustBeInactive(request) .BindT(_ => FolderMustBeEmpty(request));
