Re: [Noffle-devel] Filter crossposts using Xref instead of Newsg

[Jim H. <jim...@ac...>]

On 02-Mar-2002 Jim Hague wrote:
> On 01-Mar-2002 Mirko Liss wrote:
>> What about parsing the Xref:-Line for multiple colons?
>> The Xref is already part of the overview. Noffle doesn't
>> need to fetch additional headers then.
> 
> Well, the Xref line isn't necessarily part of the overview. RFC 2980 mandates
> the overview contain "subject, author, date, message-id, references, byte
> count, and line count" only.

I've tried all the news servers that I can connect to myself, plus examining
the source for a couple of others.

With Xref:full in overview:
        Leafnode, sn, Typhoon, INN, NewsCache, Inktomi Traffic Server.

Without Xref:full in overview format:
        Exchange, Noffle

So we can't reply on it being present and, having checked the latest news
article format draft, it does only reflect articles carried locally so we can't
reliably use it as a measure of crossposts.

However, we are in deeply ignominious company in not supporting Xref in our own
overviews, so I'm working on adding it.

The obvious way to add it (and I've received one patch that does exactly this)
is to fish it out of the articles database when servicing an XOVER. However,
this means a trip to the articles database for each article, whereas currently
servicing a XOVER just dumps content read from the group overview file. For
reasons I'm not able to enunciate clearly, I'm unhappy about adding a trip to
the article database for each article; at least not unless we move to getting
all overview info from the article database and reduce the group overview file
to holding a list of message IDs. This approach is more 'sound' from a
database point of view - only one copy of the info is held - but requires
reworking the handling of the transitory 'general info' messages in
unsubscribed groups. But adding Xref info to the group overview files involves
updating each group on crossposted articles; I don't think this is a huge
overhead, but I'd welcome comments from others.

-- 
Jim Hague - jim...@in... (Work), ji...@be... (Play)
Never trust a computer you can't lift or you don't control.