[fix] Distinguish client cancellation from server errors during slice upload (#290)

Author: paul-fresquet

src/ByteSync.Client/Interfaces/Controls/Communications/IAdaptiveUploadController.cs

@@ -1,3 +1,5 @@
+using ByteSync.Common.Business.Communications.Transfers;
+
 namespace ByteSync.Interfaces.Controls.Communications;
 
 public interface IAdaptiveUploadController
@@ -8,6 +10,5 @@ public interface IAdaptiveUploadController
 
 	int GetNextChunkSizeBytes();
 
-	void RecordUploadResult(TimeSpan elapsed, bool isSuccess, int partNumber, int? statusCode = null, 
-		Exception? exception = null, string? fileId = null, long actualBytes = -1);
+	void RecordUploadResult(UploadResult uploadResult);
 }

src/ByteSync.Client/Services/Communications/Transfers/Strategies/AzureBlobStorageUploadStrategy.cs

@@ -27,7 +27,7 @@ public async Task<UploadFileResponse> UploadAsync(FileUploaderSlice slice, FileS
             var blob = new BlobClient(new Uri(storageLocation.Url), options);
             var response = await blob.UploadAsync(slice.MemoryStream, cancellationToken);
 
-            _logger.LogDebug("UploadAvailableSlice: slice {number} is uploaded", slice.PartNumber);
+            _logger.LogDebug("UploadAvailableSlice: slice {PartNumber} is uploaded", slice.PartNumber);
 
             var rawResponse = response.GetRawResponse();
 
@@ -45,10 +45,15 @@ public async Task<UploadFileResponse> UploadAsync(FileUploaderSlice slice, FileS
                 );
             }
         }
+        catch (OperationCanceledException ex)
+        {
+            _logger.LogWarning(ex, "Upload of slice {PartNumber} was canceled or timed out", slice.PartNumber);
+            return UploadFailureClassifier.Classify(ex, cancellationToken);
+        }
         catch (Exception ex)
         {
-            _logger.LogError(ex, "Failed to upload slice {number}", slice.PartNumber);
-            return UploadFileResponse.Failure(500, ex);
+            _logger.LogError(ex, "Failed to upload slice {PartNumber}", slice.PartNumber);
+            return UploadFailureClassifier.Classify(ex, cancellationToken);
         }
     }
 }

src/ByteSync.Client/Services/Communications/Transfers/Strategies/CloudflareR2UploadStrategy.cs

@@ -76,10 +76,15 @@ public async Task<UploadFileResponse> UploadAsync(FileUploaderSlice slice, FileS
                 );
             }
         }
+        catch (OperationCanceledException ex)
+        {
+            _logger.LogWarning(ex, "Upload of slice {PartNumber} was canceled or timed out", slice.PartNumber);
+            return UploadFailureClassifier.Classify(ex, cancellationToken);
+        }
         catch (Exception ex)
         {
-            _logger.LogError(ex, "Failed to upload slice {number}", slice.PartNumber);
-            return UploadFileResponse.Failure(500, ex);
+            _logger.LogError(ex, "Failed to upload slice {PartNumber}", slice.PartNumber);
+            return UploadFailureClassifier.Classify(ex, cancellationToken);
         }
     }
 }

src/ByteSync.Client/Services/Communications/Transfers/Strategies/UploadFailureClassifier.cs

@@ -0,0 +1,23 @@
+using System;
+using System.Threading;
+using ByteSync.Common.Business.Communications.Transfers;
+
+namespace ByteSync.Services.Communications.Transfers.Strategies;
+
+public static class UploadFailureClassifier
+{
+    public static UploadFileResponse Classify(Exception exception, CancellationToken cancellationToken)
+    {
+        if (exception is OperationCanceledException && cancellationToken.IsCancellationRequested)
+        {
+            return UploadFileResponse.ClientCancellation(exception);
+        }
+        
+        if (exception is OperationCanceledException)
+        {
+            return UploadFileResponse.ClientTimeout(exception);
+        }
+
+        return UploadFileResponse.Failure(500, exception);
+    }
+}

src/ByteSync.Client/Services/Communications/Transfers/Uploading/AdaptiveUploadController.cs

@@ -1,5 +1,6 @@
 using System.Reactive.Linq;
 using ByteSync.Business.Sessions;
+using ByteSync.Common.Business.Communications.Transfers;
 using ByteSync.Interfaces.Controls.Communications;
 using ByteSync.Interfaces.Services.Sessions;
 
@@ -81,14 +82,18 @@ public int GetNextChunkSizeBytes()
         }
     }
 
-    public void RecordUploadResult(TimeSpan elapsed, bool isSuccess, int partNumber, int? statusCode = null,
-        Exception? exception = null, string? fileId = null, long actualBytes = -1)
+    public void RecordUploadResult(UploadResult uploadResult)
     {
         lock (_syncRoot)
         {
-            EnqueueSample(elapsed, isSuccess, actualBytes);
+            if (IsClientSideFailure(uploadResult.FailureKind))
+            {
+                return;
+            }
+            
+            EnqueueSample(uploadResult.Elapsed, uploadResult.IsSuccess, uploadResult.ActualBytes);
 
-            if (HandleBandwidthReset(isSuccess, statusCode))
+            if (HandleBandwidthReset(uploadResult.IsSuccess, uploadResult.StatusCode))
             {
                 return;
             }
@@ -102,18 +107,18 @@ public void RecordUploadResult(TimeSpan elapsed, bool isSuccess, int partNumber,
 
             _logger.LogDebug(
                 "Adaptive: file {FileId} maxElapsed={MaxElapsedMs} ms, window={Window}, parallelism={Parallelism}, chunkSize={ChunkKb} KB",
-                fileId ?? "-",
+                uploadResult.FileId ?? "-",
                 maxElapsed.TotalMilliseconds,
                 _windowSize,
                 _currentParallelism,
                 Math.Round(_currentChunkSizeBytes / 1024d));
 
-            if (TryHandleDownscale(maxElapsed, fileId))
+            if (TryHandleDownscale(maxElapsed, uploadResult.FileId))
             {
                 return;
             }
 
-            TryHandleUpscale(fileId);
+            TryHandleUpscale(uploadResult.FileId);
         }
     }
 
@@ -146,6 +151,11 @@ private void EnqueueSample(TimeSpan elapsed, bool isSuccess, long actualBytes)
         }
     }
 
+    private static bool IsClientSideFailure(UploadFailureKind failureKind)
+    {
+        return failureKind is UploadFailureKind.ClientCancellation or UploadFailureKind.ClientTimeout;
+    }
+    
     private bool HandleBandwidthReset(bool isSuccess, int? statusCode)
     {
         if (!isSuccess && statusCode != null)
@@ -278,7 +288,7 @@ private void TryHandleUpscale(string? fileId)
         }
     }
 
-    private double GetUpscaleMultiplier(TimeSpan maxElapsedEligible)
+    private static double GetUpscaleMultiplier(TimeSpan maxElapsedEligible)
     {
         if (maxElapsedEligible < TimeSpan.FromSeconds(1))
         {