Bug 3876 - HttpWebRequest chunked reading problem
Summary: HttpWebRequest chunked reading problem
Alias: None
Product: Class Libraries
Classification: Mono
Component: System ()
Version: master
Hardware: All All
: --- normal
Target Milestone: Untriaged
Assignee: Bugzilla
Depends on:
Reported: 2012-03-13 12:43 UTC by Gonzalo Paniagua Javier
Modified: 2012-03-13 12:48 UTC (History)
1 user (show)

Is this bug a regression?: ---
Last known good build:

Test that shows the difference between .NEt and Mono (5.56 KB, application/x-zip-compressed)
2012-03-13 12:44 UTC, Gonzalo Paniagua Javier

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Description Gonzalo Paniagua Javier 2012-03-13 12:43:06 UTC
From Mårten Ekblad in mono-list:

I have created a client app that communicates with a web service that uses the Comet way of sending events to a client. To do that I start a "long-living" HttpWebRequest to the server. The server communicates back to the client by sending chunked content (Transfer-Encoding: chunked). Individual events are then transferred in chunks. The problem for me here is that Mono seems to wait for the connection to terminate or the timeout to happen before sending the chunks back to the consumer of HttpWebRequest. This is not the case in .Net. In .Net each chunk is reported back individually when they arrive.
This is the pseudo code I'm using:
1. HttpWebRequest req = WebRequest.Create( URL...);
2. req.BeginGetRequestStream(...);
3. stream = eventContext.WebRequest.EndGetRequestStream(...);
4. StreamWriter writer = new StreamWriter(stream);
5. writer.Write(data);
6. writer.Close();
7. eventContext.RequestStream.Close();
8. eventContext.WebRequest.BeginGetResponse(...);
9. HttpWebResponse resp = (HttpWebResponse) req.EndGetResponse(asynchronousResult);
10. responseStream = resp.GetResponseStream();
11. responseStream.BeginRead(eventContext.Buffer, 0, 20000, new AsyncCallback(DataReceived), eventContext);
12. In DataReceived I do responseStream.EndRead(asynchronousResult);
13. After that I arm the read again with responseStream.BeginRead(...);

In .Net DataReceived is called on each packet. In Mono it's called after 30 seconds (probably the timeout).

Is this the intended behavior with HttpWebRequest and chunked content? Is there another recommended way of dealing Comet style web services?
Comment 1 Gonzalo Paniagua Javier 2012-03-13 12:44:00 UTC
Created attachment 1509 [details]
Test that shows the difference between .NEt and Mono
Comment 2 Gonzalo Paniagua Javier 2012-03-13 12:48:24 UTC
Fixed in mono-2-10/bad8aa4 and master/864d354