Improve comvert to mp3 task

- Improve progress reporting and cancellation performance
- Clear current book from queue before queueing single convert to mp3 task

Source/FileLiberator/ConvertToMp3.cs

@@ -1,6 +1,7 @@
 using System;
 using System.IO;
 using System.Linq;
+using System.Threading;
 using System.Threading.Tasks;
 using AAXClean;
 using AAXClean.Codecs;
@@ -19,7 +20,13 @@ namespace FileLiberator
 		private readonly AaxDecrypter.AverageSpeed averageSpeed = new();
 		private static string Mp3FileName(string m4bPath) => Path.ChangeExtension(m4bPath ?? "", ".mp3");
 
-		public override Task CancelAsync() => Mp4Operation?.CancelAsync() ?? Task.CompletedTask;		
+		private CancellationTokenSource CancellationTokenSource { get; set; }
+		public override async Task CancelAsync()
+		{
+			await CancellationTokenSource.CancelAsync();
+			if (Mp4Operation is not null)
+				await Mp4Operation.CancelAsync();
+		}
 
 		public static bool ValidateMp3(LibraryBook libraryBook)
 		{
@@ -32,17 +39,29 @@ namespace FileLiberator
 		public override async Task<StatusHandler> ProcessAsync(LibraryBook libraryBook)
 		{
 			OnBegin(libraryBook);
+			var cancellationToken = (CancellationTokenSource = new()).Token;
 
 			try
 			{
-				var m4bPaths = AudibleFileStorage.Audio.GetPaths(libraryBook.Book.AudibleProductId);
+				var m4bPaths = AudibleFileStorage.Audio.GetPaths(libraryBook.Book.AudibleProductId)
+					.Where(m4bPath => File.Exists(m4bPath))
+					.Select(m4bPath => new { m4bPath, proposedMp3Path = Mp3FileName(m4bPath), m4bSize = new FileInfo(m4bPath).Length })
+					.Where(p => !File.Exists(p.proposedMp3Path))
+					.ToArray();
 
-				foreach (var m4bPath in m4bPaths)
+				long totalInputSize = m4bPaths.Sum(p => p.m4bSize);
+				long sizeOfCompletedFiles = 0L;
+				foreach (var entry in m4bPaths)
 				{
-					var proposedMp3Path = Mp3FileName(m4bPath);
-					if (File.Exists(proposedMp3Path) || !File.Exists(m4bPath)) continue;
+					cancellationToken.ThrowIfCancellationRequested();
+					if (File.Exists(entry.proposedMp3Path) || !File.Exists(entry.m4bPath))
+					{
+						sizeOfCompletedFiles += entry.m4bSize;
+						continue;
+					}
 
-					var m4bBook = await Task.Run(() => new Mp4File(m4bPath, FileAccess.Read));
+					using var m4bFileStream = File.Open(entry.m4bPath, FileMode.Open, FileAccess.Read, FileShare.Read);
+					var m4bBook = new Mp4File(m4bFileStream);
 
 					//AAXClean.Codecs only supports decoding AAC and E-AC-3 audio.
 					if (m4bBook.AudioSampleEntry.Esds is null && m4bBook.AudioSampleEntry.Dec3 is null)
@@ -69,74 +88,85 @@ namespace FileLiberator
 						lameConfig.ID3.Track = trackCount > 0 ? $"{trackNum}/{trackCount}" : trackNum.ToString();
 					}
 
-					using var mp3File = File.Open(Path.GetTempFileName(), FileMode.OpenOrCreate, FileAccess.ReadWrite);
+					long currentFileNumBytesProcessed = 0;
 					try
 					{
-						Mp4Operation = m4bBook.ConvertToMp3Async(mp3File, lameConfig, chapters);
-						Mp4Operation.ConversionProgressUpdate += M4bBook_ConversionProgressUpdate;
-						await Mp4Operation;
-
-						if (Mp4Operation.IsCanceled)
+						var tempPath = Path.GetTempFileName();
+						using (var mp3File = File.Open(tempPath, FileMode.OpenOrCreate, FileAccess.ReadWrite))
 						{
-							FileUtility.SaferDelete(mp3File.Name);
-							return new StatusHandler { "Cancelled" };
+							Mp4Operation = m4bBook.ConvertToMp3Async(mp3File, lameConfig, chapters);
+							Mp4Operation.ConversionProgressUpdate += m4bBook_ConversionProgressUpdate;
+							await Mp4Operation;
 						}
-						else
-						{
-							var realMp3Path
+
+						if (cancellationToken.IsCancellationRequested)
+							FileUtility.SaferDelete(tempPath);
+
+						cancellationToken.ThrowIfCancellationRequested();
+
+						var realMp3Path
 								= FileUtility.SaferMoveToValidPath(
-									mp3File.Name,
-									proposedMp3Path,
+									tempPath,
+									entry.proposedMp3Path,
 									Configuration.Instance.ReplacementCharacters,
 									extension: "mp3",
 									Configuration.Instance.OverwriteExisting);
 
-							SetFileTime(libraryBook, realMp3Path);
-							SetDirectoryTime(libraryBook, Path.GetDirectoryName(realMp3Path));
-
-							OnFileCreated(libraryBook, realMp3Path);
-						}
-					}
-					catch (Exception ex)
-					{
-						Serilog.Log.Error(ex, "AAXClean error");
-						return new StatusHandler { "Conversion failed" };
+						SetFileTime(libraryBook, realMp3Path);
+						SetDirectoryTime(libraryBook, Path.GetDirectoryName(realMp3Path));
+						OnFileCreated(libraryBook, realMp3Path);
 					}
 					finally
 					{
 						if (Mp4Operation is not null)
-							Mp4Operation.ConversionProgressUpdate -= M4bBook_ConversionProgressUpdate;
+							Mp4Operation.ConversionProgressUpdate -= m4bBook_ConversionProgressUpdate;
 
-						m4bBook.InputStream.Close();
-						mp3File.Close();
+						sizeOfCompletedFiles += entry.m4bSize;
+					}
+					void m4bBook_ConversionProgressUpdate(object sender, ConversionProgressEventArgs e)
+					{
+						currentFileNumBytesProcessed = (long)(e.FractionCompleted * entry.m4bSize);
+						var bytesCompleted = sizeOfCompletedFiles + currentFileNumBytesProcessed;
+						ConversionProgressUpdate(totalInputSize, bytesCompleted);
 					}
 				}
+				return new StatusHandler();
+			}
+			catch (Exception ex)
+			{
+				if (!cancellationToken.IsCancellationRequested)
+				{
+					Serilog.Log.Error(ex, "AAXClean error");
+					return new StatusHandler { "Conversion failed" };
+				}
+				return new StatusHandler { "Cancelled" };
 			}
 			finally
 			{
 				OnCompleted(libraryBook);
+				CancellationTokenSource.Dispose();
+				CancellationTokenSource = null;
 			}
-			return new StatusHandler();
 		}
 
-		private void M4bBook_ConversionProgressUpdate(object sender, ConversionProgressEventArgs e)
+		private void ConversionProgressUpdate(long totalInputSize, long bytesCompleted)
 		{
-			averageSpeed.AddPosition(e.ProcessPosition.TotalSeconds);
+			averageSpeed.AddPosition(bytesCompleted);
 
-			var remainingTimeToProcess = (e.EndTime - e.ProcessPosition).TotalSeconds;
-			var estTimeRemaining = remainingTimeToProcess / averageSpeed.Average;
+			var remainingBytes = (totalInputSize - bytesCompleted);
+			var estTimeRemaining = remainingBytes / averageSpeed.Average;
 
 			if (double.IsNormal(estTimeRemaining))
 				OnStreamingTimeRemaining(TimeSpan.FromSeconds(estTimeRemaining));
 
-			double progressPercent = 100 * e.FractionCompleted;
+			double progressPercent = 100 * bytesCompleted / totalInputSize;
 
 			OnStreamingProgressChanged(
 				new DownloadProgress
 				{
 					ProgressPercentage = progressPercent,
-					BytesReceived = (long)(e.ProcessPosition - e.StartTime).TotalSeconds,
-					TotalBytesToReceive = (long)(e.EndTime - e.StartTime).TotalSeconds
+					BytesReceived = bytesCompleted,
+					TotalBytesToReceive = totalInputSize
 				});
 		}
 	}

Source/LibationUiBase/ProcessQueue/ProcessQueueViewModel.cs

@@ -111,6 +111,8 @@ public class ProcessQueueViewModel : ReactiveObject
 		var preLiberated = libraryBooks.Where(lb => !lb.AbsentFromLastScan && lb.Book.UserDefinedItem.BookStatus is LiberatedStatus.Liberated && lb.Book.ContentType is DataLayer.ContentType.Product).ToArray();
 		if (preLiberated.Length > 0)
 		{
+			if (preLiberated.Length == 1)
+				RemoveCompleted(preLiberated[0]);
 			Serilog.Log.Logger.Information("Begin convert {count} books to mp3", preLiberated.Length);
 			AddConvertMp3(preLiberated);
 			return true;