写入请求流时请求被中止错误

1 回答

• 1

  我建议直接从文件系统转移到异步并写入文件以请求以避免内存中的1.5GB三重缓冲（下面的警告未经过测试） .

  public async Task<HttpWebResponse> PushFileToWistiaAsync(string contentFilePath)
  {
      string boundary = "---------------------------" + DateTime.Now.Ticks.ToString("x");
      string contentBoundary = "\r\n--" + boundary + "\r\n";
  
      StringBuilder wistiaMetadataBuilder = new StringBuilder();
      wistiaMetadataBuilder.Append("--" + boundary + "\r\n");
      // Append all the wistia config and setting here
  
      byte[] wistiaMetadata = Encoding.UTF8.GetBytes(wistiaMetadataBuilder.ToString());
      byte[] requestBoundary = Encoding.UTF8.GetBytes(contentBoundary);
  
      ServicePointManager.Expect100Continue = false;
  
      HttpWebRequest request = (HttpWebRequest)WebRequest.Create(AppConfig.WistiaCustomCourseBucket);
      request.Method = "POST";
      request.Headers.Clear();
      request.Expect = String.Empty;
      request.ContentType = "multipart/form-data; boundary=" + boundary;
  
      Stream requestStream = await request.GetRequestStreamAsync();
      await requestStream.WriteAsync(wistiaMetadata, 0, wistiaMetadata.Length);
      using (FileStream wistiaFileStream = new FileStream(contentFilePath, FileMode.Open, FileAccess.Read))
      {
          byte[] wistiaFileBuffer = new byte[500 * 1024];
          int wistiaFileBytesRead = 0;
  
          while ((wistiaFileBytesRead = await wistiaFileStream.ReadAsync(wistiaFileBuffer, 0, wistiaFileBuffer.Length)) != 0)
          {
              await requestStream.WriteAsync(wistiaFileBuffer, 0, wistiaFileBytesRead);
              await requestStream.FlushAsync();
          }
      }
      await requestStream.WriteAsync(requestBoundary, 0, requestBoundary.Length);
  
      return (HttpWebResponse)(await request.GetResponseAsync());
  }
  

  您应该使用缓冲区大小，一次读取的数据量和 request.SendChunked 来实现合理的性能 .

  这是另一种方法（非异步，因此可能是最差的可扩展性），它直接从缓冲区到请求：

  public HttpWebResponse PushFileToWistia(byte[] contentFileByteArray)
  {
      string boundary = "---------------------------" + DateTime.Now.Ticks.ToString("x");
      string contentBoundary = "\r\n--" + boundary + "\r\n";
  
      StringBuilder wistiaMetadataBuilder = new StringBuilder();
      wistiaMetadataBuilder.Append("--" + boundary + "\r\n");
      // Append all the wistia config and setting here
  
      byte[] wistiaMetadata = Encoding.UTF8.GetBytes(wistiaMetadataBuilder.ToString());
      byte[] requestBoundary = Encoding.UTF8.GetBytes(contentBoundary);
  
      ServicePointManager.Expect100Continue = false;
  
      HttpWebRequest request = (HttpWebRequest)WebRequest.Create(AppConfig.WistiaCustomCourseBucket);
      request.Method = "POST";
      request.Headers.Clear();
      request.Expect = String.Empty;
      request.ContentType = "multipart/form-data; boundary=" + boundary;
      request.ContentLength = wistiaMetadata.Length + contentFileByteArray.Length + requestBoundary.Length
  
      // You can play with SendChunked and AllowWriteStreamBuffering to control the size of chunks you send and performance
      //request.SendChunked = true;
      //request.AllowWriteStreamBuffering = false;
  
      int contentFileChunkSize = 500 * 1024;
      int contentFileBytesRead = 0;
  
      Stream requestStream = request.GetRequestStream();
      requestStream.Write(wistiaMetadata, 0, wistiaMetadata.Length);
      while (contentFileBytesRead < contentFileByteArray.Length)
      {
          if ((contentFileBytesRead + contentFileChunkSize) > contentFileByteArray.Length)
          {
              contentFileChunkSize = contentFileByteArray.Length - contentFileBytesRead;
          }
  
          requestStream.Write(contentFileByteArray, contentFileBytesRead, contentFileChunkSize);
          requestStream.Flush();
  
          contentFileBytesRead += contentFileChunkSize;
      }
      requestStream.Write(requestBoundary, 0, requestBoundary.Length);
      requestStream.Close();
  
      // You might need to play with request.Timeout here
      return (HttpWebResponse)request.GetResponse();
  }
  

  此外，如果您在Web应用程序中执行此操作并且希望使用异步方法，则需要一直“异步/等待”（因此异步控制器中的异步操作等） .

  一般情况下，我不鼓励将此作为Web应用程序中请求处理的一部分（从用户角度观察的总时间将是上传到您的应用程序然后到Wistia的总和，这可能比客户端超时允许的多得多） . 在这种情况下，通常最好保存文件并安排其他一些“后台任务”来完成上传作业 .

  回复于 2024-04-20T22:25:39+08:00