Multi-threaded upload

src/Altinn.Broker.Integrations/Azure/AzureStorageService.cs

@@ -18,6 +18,7 @@ public class AzureStorageService(IResourceManager resourceManager, ILogger<Azure
 {
     private const int BLOCK_SIZE = 1024 * 1024 * 32; // 32MB
     private const int BLOCKS_BEFORE_COMMIT = 5;
+    private const int UPLOAD_THREADS = 3;
 
     private async Task<BlobContainerClient> GetBlobContainerClient(FileTransferEntity fileTransferEntity, ServiceOwnerEntity serviceOwnerEntity)
     {
@@ -51,7 +52,7 @@ public async Task<Stream> DownloadFile(ServiceOwnerEntity serviceOwnerEntity, Fi
     }
 
     public async Task<string?> UploadFile(ServiceOwnerEntity serviceOwnerEntity, FileTransferEntity fileTransferEntity,
-                                          Stream stream, long streamLength, CancellationToken cancellationToken)
+                                      Stream stream, long streamLength, CancellationToken cancellationToken)
     {
         logger.LogInformation($"Starting upload of {fileTransferEntity.FileTransferId} for {serviceOwnerEntity.Name}");
         var stopwatch = System.Diagnostics.Stopwatch.StartNew();
@@ -61,12 +62,14 @@ public async Task<Stream> DownloadFile(ServiceOwnerEntity serviceOwnerEntity, Fi
             BlockBlobClient blockBlobClient = blobContainerClient.GetBlockBlobClient(fileTransferEntity.FileTransferId.ToString());
 
             using var accumulationBuffer = new MemoryStream();
-            var networkReadBuffer = new byte[1024*1024]; 
+            var networkReadBuffer = new byte[1024 * 1024];
             var blockList = new List<string>();
             long position = 0;
             using var blobMd5 = MD5.Create();
 
             int blocksInBatch = 0;
+            var commitTasks = new List<Task>();
+            var semaphore = new SemaphoreSlim(UPLOAD_THREADS); // Limit to 3 concurrent commit operations
 
             while (position < streamLength)
             {
@@ -88,21 +91,41 @@ public async Task<Stream> DownloadFile(ServiceOwnerEntity serviceOwnerEntity, Fi
                     blockList.Add(blockId);
                     blocksInBatch++;
                     accumulationBuffer.SetLength(0); // Clear accumulation buffer for next block
+
                     if (blocksInBatch >= BLOCKS_BEFORE_COMMIT)
                     {
-                        logger.LogInformation($"Committing intermediate batch of {blocksInBatch} blocks at position " +
+                        logger.LogInformation($"Queuing commit of {blocksInBatch} blocks at position " +
                             $"{position / (1024.0 * 1024.0 * 1024.0):N2} GiB");
 
-                        await CommitBlocks(blockBlobClient, blockList, firstCommit: blockList.Count == blocksInBatch, null, cancellationToken);
+                        var blocksToCommit = blockList.ToList();
+                        var isFirstCommit = blockList.Count == blocksInBatch;
+
+                        commitTasks.Add(CommitBlocksAsync());
+                        async Task CommitBlocksAsync()
+                        {
+                            try
+                            {
+                                await semaphore.WaitAsync(cancellationToken);
+                                await CommitBlocks(blockBlobClient, blocksToCommit, firstCommit: isFirstCommit, null, cancellationToken);
+
+                                var uploadSpeedMBps = position / (1024.0 * 1024) / (stopwatch.ElapsedMilliseconds / 1000.0);
+                                logger.LogInformation($"Completed intermediate commit. Upload progress for {fileTransferEntity.FileTransferId}: " +
+                                    $"{position / (1024.0 * 1024.0 * 1024.0):N2} GiB ({uploadSpeedMBps:N2} MB/s)");
+                            }
+                            finally
+                            {
+                                semaphore.Release();
+                            }
+                        }
+
                         blocksInBatch = 0;
-                        // Keep the block list for the final commit
-                        var uploadSpeedMBps = position / (1024.0 * 1024) / (stopwatch.ElapsedMilliseconds / 1000.0);
-                        logger.LogInformation($"Upload progress for {fileTransferEntity.FileTransferId}: " +
-                            $"{position / (1024.0 * 1024.0 * 1024.0):N2} GiB ({uploadSpeedMBps:N2} MB/s)");
                     }
                 }
             }
 
+            // Wait for all pending commits to complete
+            await Task.WhenAll(commitTasks);
+
             // Final commit with all blocks
             blobMd5.TransformFinalBlock(Array.Empty<byte>(), 0, 0);
             if (blobMd5.Hash is null)
@@ -126,6 +149,7 @@ public async Task<Stream> DownloadFile(ServiceOwnerEntity serviceOwnerEntity, Fi
         }
     }
 
+
     private async Task UploadBlock(BlockBlobClient client, string blockId, byte[] blockData, CancellationToken cancellationToken)
     {
         await BlobRetryPolicy.ExecuteAsync(async () =>