/// <summary>
/// Retrieves the article headers for the specified range. Since this iterates over the article identifiers and
/// that range may contain identifiers that are not legal (i.e. they don't exist on the server), this method will
/// catch NNTP RFC 997 423 response codes and therefore skip the article identifier.
/// </summary>
/// <param name="firstArticleId">The first article id.</param>
/// <param name="lastArticleId">The last article id.</param>
/// <returns></returns>
public virtual IEnumerable <ArticleHeadersDictionary> RetrieveArticleHeaders(int firstArticleId, int lastArticleId)
{
if (!CurrentGroupSelected)
{
throw new NntpGroupNotSelectedException();
}
for (; firstArticleId < lastArticleId; firstArticleId++)
{
ArticleHeadersDictionary d = null;
try
{
d = RetrieveArticleHeader(firstArticleId);
}
catch (NntpResponseException error)
{
if (error.LastResponseCode == 423)
{
continue;
}
throw error;
}
yield return(d);
}
}
/// <summary>
/// Retrieves the article headers for the specified range.
/// </summary>
/// <param name="firstArticleId">The first article id.</param>
/// <param name="lastArticleId">The last article id.</param>
/// <returns></returns>
public override IEnumerable <ArticleHeadersDictionary> RetrieveArticleHeaders(int firstArticleId, int lastArticleId)
{
if (!CurrentGroupSelected)
{
throw new NntpGroupNotSelectedException();
}
if (m_supportsXover)
{
string[] headerNames = new string[] { "Article-ID", "Subject", "From", "Date", "Message-ID", "Xref", "Bytes", "Lines" };
foreach (string s in DoArticleCommand("XOVER " + firstArticleId + "-" + lastArticleId, 224))
{
ArticleHeadersDictionary headers = new ArticleHeadersDictionary();
string[] fields = s.Split('\t');
for (int i = 0; i < headerNames.Length; i++)
{
headers.AddHeader(headerNames[i], fields[i]);
}
yield return(headers);
}
}
else
{
// I can't use the base class to do this.
for (; firstArticleId < lastArticleId; firstArticleId++)
{
yield return(RetrieveArticleHeader(firstArticleId));
}
}
}
/// <summary>
/// Retrieves the article header common functionality. The command argument
/// should be in the form "HEAD [article-id|message-id]."
/// </summary>
/// <param name="command">The command.</param>
/// <returns></returns>
protected ArticleHeadersDictionary RetrieveArticleHeaderCore(string command)
{
ArticleHeadersDictionary headers = new ArticleHeadersDictionary();
foreach (string s in DoArticleCommand(command, Rfc977ResponseCodes.ArticleRetrievedHeadFollows))
{
if (s.Length == 0)
{
break;
}
else
{
headers.AddHeader(s);
}
}
return(headers);
}
