Restored previous single shot upload threshold (Azure#16365)

* Restored previous single shot upload threshold

* PR comments

* PR comments

* PR comments

Author: seanmcc-msft

sdk/storage/Azure.Storage.Blobs/CHANGELOG.md

@@ -10,6 +10,7 @@
 - Added CanAccountGenerateSasUri property, GenerateAccountSasUri() to BlobServiceClient.
 - Deprecated property BlobSasBuilder.Version, so when generating SAS will always use the latest Storage Service SAS version.
 - Added ability to get parent BlobContainerClient from BlobBaseClient and to get parent BlobServiceClient from BlobContainerClient.
+- Restored single upload threshold for parallel uploads from 5 TB to 256 MB.
 
 ## 12.7.0-preview.1 (2020-09-30)
 - Added support for service version 2020-02-10.

sdk/storage/Azure.Storage.Blobs/tests/BlockBlobClientTests.cs

@@ -2098,6 +2098,48 @@ await blob.UploadAsync(
             Assert.AreEqual(blobSize, progress.List[progress.List.Count - 1]);
         }
 
+        [LiveOnly]
+        [Test]
+        public async Task UploadAsync_SingleUpload_DefaultThreshold()
+        {
+            await using DisposingContainer test = await GetTestContainerAsync();
+
+            // Arrange
+            var blockBlobName = GetNewBlobName();
+            BlockBlobClient blob = InstrumentClient(test.Container.GetBlockBlobClient(blockBlobName));
+            long blobSize = Constants.Blob.Block.Pre_2019_12_12_MaxUploadBytes - 1;
+            var data = GetRandomBuffer(blobSize);
+            using Stream stream = new MemoryStream(data);
+
+            // Act
+            await blob.UploadAsync(content: stream);
+
+            // Assert
+            Response<BlockList> blockListResponse = await blob.GetBlockListAsync();
+            Assert.AreEqual(0, blockListResponse.Value.CommittedBlocks.ToList().Count);
+        }
+
+        [LiveOnly]
+        [Test]
+        public async Task UploadAsync_MultipleUpload_DefaultThreshold()
+        {
+            await using DisposingContainer test = await GetTestContainerAsync();
+
+            // Arrange
+            var blockBlobName = GetNewBlobName();
+            BlockBlobClient blob = InstrumentClient(test.Container.GetBlockBlobClient(blockBlobName));
+            long blobSize = Constants.Blob.Block.Pre_2019_12_12_MaxUploadBytes + 1;
+            var data = GetRandomBuffer(blobSize);
+            using Stream stream = new MemoryStream(data);
+
+            // Act
+            await blob.UploadAsync(content: stream);
+
+            // Assert
+            Response<BlockList> blockListResponse = await blob.GetBlockListAsync();
+            Assert.AreEqual(33, blockListResponse.Value.CommittedBlocks.ToList().Count);
+        }
+
         [Test]
         [ServiceVersion(Min = BlobClientOptions.ServiceVersion.V2019_12_12)]
         public async Task UploadAsync_VersionId()

sdk/storage/Azure.Storage.Common/src/Shared/PartitionedUploader.cs

@@ -130,7 +130,7 @@ public PartitionedUploader(
             }
             else
             {
-                _singleUploadThreshold = Constants.Blob.Block.MaxUploadBytes;
+                _singleUploadThreshold = Constants.Blob.Block.Pre_2019_12_12_MaxUploadBytes;
             }
 
             // Set _blockSize

sdk/storage/Azure.Storage.Files.DataLake/CHANGELOG.md

@@ -8,6 +8,7 @@
 - Added ability to set Position on streams created with DataLakeFileClient.OpenRead().
 - Added CanGenerateSasUri property and GenerateSasUri() to DataLakePathClient, DataLakeFileClient, DataLakeDirectoryClient and DataLakeFileSystemClient.
 - Added CanGenerateAccountSasUri property and GenerateAccountSasUri() to DataLakeServiceClient.
+- Restored single upload threshold for parallel uploads from 5 TB to 256 MB.
 
 ## 12.5.0-preview.1 (2020-09-30)
 - Added support for service version 2020-02-10.