写请求流时请求被中止错误

Question

public HttpWebResponse PushFileToWistia(byte[] contentFileByteArray, string fileName) 
    { 
     StringBuilder postDataBuilder = new StringBuilder(); 
     postDataBuilder.Append("I am appending all the wistia config and setting here"); 
     byte[] postData = null; 
     using (MemoryStream postDataStream = new MemoryStream()) 
     { 
      byte[] postDataBuffer = Encoding.UTF8.GetBytes(postDataBuilder.ToString()); 
      postDataStream.Write(postDataBuffer, 0, postDataBuffer.Length); 
      postDataStream.Write(contentFileByteArray, 0, contentFileByteArray.Length); 
      postDataBuffer = Encoding.UTF8.GetBytes("\r\n--" + boundary + "--"); 
      postDataStream.Write(postDataBuffer, 0, postDataBuffer.Length); 
      postData = postDataStream.ToArray(); 
     } 

     ServicePointManager.Expect100Continue = false; 
     HttpWebRequest request = (HttpWebRequest)WebRequest.Create(AppConfig.WistiaCustomCourseBucket); 
     request.Method = "POST"; 
     request.Expect = String.Empty; 
     request.Headers.Clear(); 
     request.ContentType = "multipart/form-data; boundary=" + boundary; 
     request.ContentLength = postData.Length; 

     Stream requestStream = request.GetRequestStream(); 
     requestStream.Write(postData, 0, postData.Length); //for file > 100mb this call throws and error --the requet was aborted. the request was canceled. 
     requestStream.Flush(); 
     requestStream.Close(); 

     HttpWebResponse response = (HttpWebResponse)request.GetResponse(); 
     return response; 
     } 

上述代码适用于视频文件mp4小于50mb。但是，当我尝试上传一个100MB的文件时，它会抛出异常（请求被中止）。我需要支持的文件大小高达1.5GB所以现在我不确定这种方法对于如此大的文件大小上传是否正确。任何建议在正确的方向将是有益的...谢谢（我想上传文件到Wistia服务器） 在这一行发生异常 - requestStream.Write（postData，0，postData.Length）;

我试图改变的web.config的设置，但没有奏效： 的httpRuntime targetFramework = “4.5” 的maxRequestLength = “2048576” executionTimeout = “12000” requestLengthDiskThreshold = “1024”

----- -async呼叫-------

 MemoryStream wistiaFileStream = null; 
     using (MemoryStream postDataStream = new MemoryStream()) 
     { 
      postDataStream.Write(contentFileByteArray, 0, contentFileByteArray.Length); 
      wistiaFileStream = postDataStream; 
      postDataStream.Flush(); 
      postDataStream.Close(); 
     } 

     Stream requestStream = await request.GetRequestStreamAsync(); 
     await requestStream.WriteAsync(wistiaMetadata, 0, wistiaMetadata.Length); 

using (wistiaFileStream) 
     { 
      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); 
     } 

Answer 1

我建议移动到异步并直接从文件系统写入文件，以避免在存储器1.5GB的三重缓冲请求（下面警告是不测试）。

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()); 
} 

你应该和缓冲区大小，你读一次，并request.SendChunked实现合理的性能数据量播放。

这里是另一种方法（不是异步那么可能是最坏的可扩展性），这直接wirtes从缓冲区要求：

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，如果你的Web应用程序这样做的，你要使用异步方法，你需要“异步/等待“（async控制器中的异步操作等）。

一般来说，我会劝阻这样做，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应该是上传到您的应用程序，然后到Wistia的总和，这可能远远超过客户端超时允许） 。在这种情况下，通常最好保存文件并安排一些其他“后台任务”来完成上传作业。