protected override void Run()
{
List <string> result = new List <string>(500);
try {
NntpWebRequest request = (NntpWebRequest)WebRequest.Create(IdentityNewsServerManager.BuildNntpRequestUri(serverDef));
request.Method = "LIST";
if (!string.IsNullOrEmpty(serverDef.AuthUser))
{
IBanditFeedSource extension = app.BanditFeedSourceExtension;
if (extension != null)
{
request.Credentials = extension.GetFeedCredentials(serverDef);
}
//string u = null, p = null;
//FeedSource.GetNntpServerCredentials(serverDef, ref u, ref p);
//request.Credentials = FeedSource.CreateCredentialsFrom(u, p);
}
//TODO: implement proxy support in NntpWebRequest
request.Proxy = app.Proxy;
request.Timeout = 1000 * 60; // default timeout: 1 minute
if (serverDef.Timeout > 0)
{
request.Timeout = serverDef.Timeout * 1000 * 60; // sd.Timeout specified in minutes, but we need msecs
}
WebResponse response = request.GetResponse();
foreach (string s in NntpParser.GetNewsgroupList(response.GetResponseStream()))
{
result.Add(s);
}
this.Newsgroups = result;
} catch (System.Threading.ThreadAbortException) {
// eat up
} catch (Exception ex) {
p_operationException = ex;
} finally {
WorkDone.Set();
}
} // Run
/// <summary>
/// Used to create an HTTP request.
/// </summary>
/// <param name="requestParameter">Could be modified for each subsequent request</param>
internal WebRequest PrepareRequest(RequestParameter requestParameter)
{
if (requestParameter == null)
{
throw new ArgumentNullException("requestParameter");
}
// here are the exceptions caused:
WebRequest webRequest = WebRequest.Create(requestParameter.RequestUri);
HttpWebRequest httpRequest = webRequest as HttpWebRequest;
FileWebRequest fileRequest = webRequest as FileWebRequest;
NntpWebRequest nntpRequest = webRequest as NntpWebRequest;
if (httpRequest != null)
{
// set extended HttpWebRequest params
httpRequest.Timeout = Convert.ToInt32(requestParameter.Timeout.TotalMilliseconds); // default: two minutes timeout
httpRequest.UserAgent = FullUserAgent(requestParameter.UserAgent);
httpRequest.Proxy = requestParameter.Proxy;
httpRequest.AllowAutoRedirect = false;
httpRequest.AutomaticDecompression = DecompressionMethods.GZip |
DecompressionMethods.Deflate;
if (requestParameter.Headers != null)
{
httpRequest.Headers.Add(requestParameter.Headers);
}
// due to the reported bug 893620 some web server fail with a server error 500
// if we send DateTime.MinValue as IfModifiedSince. Smoe Unix derivates only know
// about valid lowest DateTime around 1970. So in the case we use the
// httpRequest class default setting:
if (requestParameter.LastModified > MinValue)
{
httpRequest.IfModifiedSince = requestParameter.LastModified;
}
/* #if DEBUG
* // further to investigate: with this setting we don't leak connections
* // (try TCPView from http://www.sysinternals.com)
* // read:
* // * http://support.microsoft.com/default.aspx?scid=kb%3Ben-us%3B819450
* // * http://cephas.net/blog/2003/10/29/the_intricacies_of_http.html
* // * http://weblogs.asp.net/jan/archive/2004/01/28/63771.aspx
*
* httpRequest.KeepAlive = false; // to prevent open HTTP connection leak
* httpRequest.ProtocolVersion = HttpVersion.Version10; // to prevent "Underlying connection closed" exception(s)
#endif */
if (httpRequest.Proxy == null)
{
httpRequest.KeepAlive = false;
httpRequest.Proxy = WebRequest.DefaultWebProxy;
httpRequest.Proxy.Credentials = CredentialCache.DefaultCredentials;
}
if (requestParameter.ETag != null)
{
httpRequest.Headers.Add("If-None-Match", requestParameter.ETag);
httpRequest.Headers.Add("A-IM", "feed");
}
if (requestParameter.Credentials != null)
{
httpRequest.KeepAlive = true; // required for authentication to succeed
httpRequest.ProtocolVersion = HttpVersion.Version11; // switch back
httpRequest.Credentials = requestParameter.Credentials;
}
if (requestParameter.ClientCertificate != null)
{
httpRequest.ClientCertificates.Add(requestParameter.ClientCertificate);
httpRequest.Timeout *= 2; // double the timeout (SSL && Client Certs used!)
}
if (requestParameter.SetCookies)
{
HttpCookieManager.SetCookies(httpRequest);
}
if (requestParameter.Cookies != null)
{
httpRequest.CookieContainer = new CookieContainer();
httpRequest.CookieContainer.Add(requestParameter.Cookies);
}
//this prevents the feed mixup issue that we've been facing. See
//http://www.davelemen.com/archives/2006/04/rss_bandit_feeds_mix_up.html
//for a user complaint about the issue.
httpRequest.Pipelined = false;
}
else if (fileRequest != null)
{
fileRequest.Timeout = DefaultTimeout;
if (requestParameter.Credentials != null)
{
fileRequest.Credentials = requestParameter.Credentials;
}
}
else if (nntpRequest != null)
{
// ten minutes timeout. Large timeout is needed if this is first time we are fetching news
//TODO: move the timeout handling to the requestor
nntpRequest.Timeout = DefaultTimeout * 5;
if (requestParameter.Credentials != null)
{
nntpRequest.Credentials = requestParameter.Credentials;
}
if (requestParameter.LastModified > MinValue)
{
nntpRequest.IfModifiedSince = requestParameter.LastModified;
}
}
else
{
throw new NotImplementedException("Unsupported WebRequest type: " + webRequest.GetType());
}
return(webRequest);
}
