private void PrepareWebRequestForContentUpload(HttpWebRequest webRequest, HttpRequestMessage request)
{
HttpContent requestContent = request.Content;
if (requestContent == null)
{
// If we have no content, we set the Content-Length to 0, regardless of the Transfer-Encoding header.
webRequest.ContentLength = 0;
}
else
{
MediaTypeHeaderValue contentType = requestContent.Headers.ContentType;
if (contentType != null)
{
webRequest.ContentType = contentType.ToString();
}
// Determine how to communicate the length of the request content.
if (request.Headers.TransferEncodingChunked == true)
{
webRequest.SendChunked = true;
}
else
{
long?contentLength = requestContent.Headers.ContentLength;
if (contentLength != null)
{
webRequest.ContentLength = (long)contentLength;
}
else
{
// If we don't have a content length and we don't use chunked, then we must buffer the content.
// If the user specified a zero buffer size, we throw.
if (maxRequestContentBufferSize == 0)
{
throw new HttpException(
"The content length of the request content can't be determined. Either set TransferEncodingChunked to true, load content into buffer, or set AllowRequestContentBuffering to true.");
}
// HttpContent couldn't calculate the content length. Chunked is not specified. Buffer the
// content to get the content length.
// Note that we call LoadIntoBuffer() synchronously since the scenario where neither the length
// is known nor chunked is used, often means that we're about to serialize in-memory data like
// XML, objects, feed content, etc. I.e. loading sync results in better perf. than async.
// If customers want to use async buffering (e.g. the source is a network stream with
// unknown length), LoadIntoBufferAsync() can be called before sending the request. In this
// case the length is known and we'll not end up here.
requestContent.LoadIntoBuffer(maxRequestContentBufferSize);
contentLength = requestContent.Headers.ContentLength;
Contract.Assert(contentLength != null, "After buffering content, ContentLength must not be null.");
webRequest.ContentLength = (long)contentLength;
}
}
}
}