C＃HTTP PUT请求代码问题

Question

I am trying to send a file to S3 via a PUT request URL that Amazon S3 has already generated for me.

My code works fine for small files, but it errors out on large files (>100 mb) after a few minutes of sending.

There error is: The request was aborted: The request was canceled. at System.Net.ConnectStream.InternalWrite(Boolean async, Byte[] buffer, Int32 offset, Int32 size, AsyncCallback callback, Object state) at System.Net.ConnectStream.Write(Byte[] buffer, Int32 offset, Int32 size)

Can someone please tell me what is wrong with my code that is stopping it from sending large files? It is not due to the Amazon PUT request URL expiring because I have that set to 30 minutes and the problem occurs after just a few minutes of sending.

The code eventually exceptions out on this line of code: dataStream.Write(byteArray, 0, byteArray.Length);

Once again, it works great for smaller files that I am sending to S3. Just not large files.

WebRequest request = WebRequest.Create(PUT_URL_FINAL[0]);
//PUT_URL_FINAL IS THE PRE-SIGNED AMAZON S3 URL THAT I AM SENDING THE FILE TO

request.Timeout = 360000; //6 minutes

request.Method = "PUT";

//result3 is the filename that I am sending                                     
request.ContentType =
    MimeType(GlobalClass.AppDir + Path.DirectorySeparatorChar + "unzip" +
             Path.DirectorySeparatorChar +
             System.Web.HttpUtility.UrlEncode(result3));

byte[] byteArray =
    File.ReadAllBytes(
        GlobalClass.AppDir + Path.DirectorySeparatorChar + "unzip" +
        Path.DirectorySeparatorChar +
        System.Web.HttpUtility.UrlEncode(result3));

request.ContentLength = byteArray.Length;
Stream dataStream = request.GetRequestStream();

// this is the line of code that it eventually quits on.  
// Works fine for small files, not for large ones
dataStream.Write(byteArray, 0, byteArray.Length); 

dataStream.Close();

//This will return "OK" if successful.
WebResponse response = request.GetResponse();
Console.WriteLine("++ HttpWebResponse: " +
                  ((HttpWebResponse)response).StatusDescription);

Answer 1

使用Fiddler或Wireshark来比较线路工作时的线路（第三方工具）和不工作时（你的代码）......一旦你知道了差异，就可以相应地改变你的代码......

Answer 2

You should set the Timeout property of the WebRequest to a higher value. It causes the request to time out before it is completed.

Answer 3

I would try writing it in chunks and splitting up the byte array. It may be choking on one large chunk.

Something like this:

        const int chunkSize = 500;
        for (int i = 0; i < byteArray.Length; i += chunkSize)
        {
            int count = i + chunkSize > byteArray.Length ? byteArray.Length - i : chunkSize;
            dataStream.Write(byteArray, i, count);
        }

May want to double-check that to make sure it wrote everything, I only did very basic testing on it.

Answer 4

Just a rough guess, but shouldn't you have:

request.ContentLength = byteArray.LongLength;

instead of:

request.ContentLength = byteArray.Length;

Having second thought, 100 MB = 100 * 1024 * 1024 < 2^32, so it probably won't be the problem