Azure 存储：BlobClient 在上传大文件时不断自我重置

Question

我正在尝试从连接到快速 Wifi 连接的手机上传 200 MB 的视频文件。我正在使用适用于 .NET 的 Azure Storage SDK v12，但以下代码在大约 30% 的上传进度后会自行重置。重置时，进度从 0 开始，不抛出异常。

await blobClient.UploadAsync(stream, progressHandler: new Progress<long>(progress =>
{
     // show progress bar
}), cancellationToken: cancellationToken);

v12 支持上传大文件吗？如果我没记错的话，旧的 API 可以上传单个块。我的印象是上面的上传方法会隐式处理分块。

如何使用最新的 sdk 上传大文件？

附：我尝试以非常高的并发性和 1 MB 的传输大小传递 StorageTransferOptions，但没有任何区别。

编辑：等待了很长时间，我能够得到一个异常抛出。我看到多个任务因为

而被取消

Cannot access a disposed object.
Object name: 'MobileAuthenticatedStream'.

  at Mono.Net.Security.MobileAuthenticatedStream.StartOperation (Mono.Net.Security.MobileAuthenticatedStream+OperationType type, Mono.Net.Security.AsyncProtocolRequest asyncRequest, System.Threading.CancellationToken cancellationToken) [0x00245] in /Users/builder/jenkins/workspace/archive-mono/2020-02/android/release/mcs/class/System/Mono.Net.Security/MobileAuthenticatedStream.cs:410 
  at System.Net.Http.HttpConnection.WriteAsync (System.ReadOnlyMemory`1[T] source) [0x00118] in /Users/builder/jenkins/workspace/archive-mono/2020-02/android/release/external/corefx/src/System.Net.Http/src/System/Net/Http/SocketsHttpHandler/HttpConnection.cs:1008 
  at System.IO.Stream.CopyToAsyncInternal (System.IO.Stream destination, System.Int32 bufferSize, System.Threading.CancellationToken cancellationToken) [0x000e7] in /Users/builder/jenkins/workspace/archive-mono/2020-02/android/release/external/corert/src/System.Private.CoreLib/shared/System/IO/Stream.cs:152 
  at Azure.Core.RequestContent+StreamContent.WriteToAsync (System.IO.Stream stream, System.Threading.CancellationToken cancellation) [0x00094] in <7b1dc95b0b4841539beb48023c1128d3>:0 
  at Azure.Core.Pipeline.HttpClientTransport+PipelineRequest+PipelineContentAdapter.SerializeToStreamAsync (System.IO.Stream stream, System.Net.TransportContext context) [0x0007c] in <7b1dc95b0b4841539beb48023c1128d3>:0 
  at System.Net.Http.HttpContent.CopyToAsyncCore (System.Threading.Tasks.ValueTask copyTask) [0x00022] in /Users/builder/jenkins/workspace/archive-mono/2020-02/android/release/external/corefx/src/System.Net.Http/src/System/Net/Http/HttpContent.cs:361 

所以blobClient 中似乎内置了并行化，但它仍然失败了。此外，我不能使用https://www.nuget.org/packages/Microsoft.Azure.Storage.DataMovement，因为它不适用于Xamarin Forms。

Answer 1

如果要将文件分块上传到 Azure Blob 存储，请参考以下代码

public async Task upload(Stream stream){
            string connectionString = "";
            string containerName = "upload";
            string blobName = "";
            BlockBlobClient blobClient = new BlockBlobClient(connectionString, containerName, blobName);
           
            List<string> blockList = new List<string>();

                while (true) {
                    byte[] b = new byte[1024 * 1024];
                    var n = await stream.ReadAsync(b, 0, 1024 * 1024);
                    if (n == 0) break;
                    string blockId = Guid.NewGuid().ToString();
                    string base64BlockId = Convert.ToBase64String(Encoding.UTF8.GetBytes(blockId));
                    await blobClient.StageBlockAsync(base64BlockId, new MemoryStream(b, true));
                    blockList.Add(base64BlockId);
                }

                await blobClient.CommitBlockListAsync(blockList);

   
}

---

更新

如果要使用sas token，请参考以下代码

var uri = new Uri($"https://{storageAccountName}.blob.core.windows.net/{containerName}/{blobName}?{sasToken}");
BlockBlobClient blobClient = new BlockBlobClient(uri);

Answer 2

v12 同时具有 BlobClient 和 BlockBlobClient。就是BlockBlobClient，它具有分块并上传每个块的功能。

你可以试试 Microsoft.Azure.Storage.DataMovement https://www.nuget.org/packages/Microsoft.Azure.Storage.DataMovement

“Microsoft Azure Storage DataMovement Library 提供了一组 API 扩展现有的 Azure Storage .Net 客户端库以提供帮助 客户传输高性能 Azure Blob 和文件存储， 可扩展性和可靠性。”