Re: fetch only a portion of an article? (nnimap mainly)

["Ted Zlatanov" <tzz@lifelogs.com>]

On Fri, 04 Mar 2005, jas@extundo.com wrote:

> IMAP support partial retrieval (byte counts), and even retrieval based
> on the selected MIME structures (i.e., retrieve entire message except
> one big attachment).  I think the problem may be in designing the back
> end interface properly, so it is flexible enough.  

Can you write the nnimap function to get N bytes with an extra
parameter (you can merge it with nnimap-request-article-part or not,
up to you)?

I'll do the rest of the API.

> Ideally there should be some way to retrieve the MIME structure of
> an article, and then make Gnus chose which MIME parts to retrieve.

I'll take a look at that stuff.  Unfortunately the other backends
don't support this, so it's less useful than a line count IMO
(although it can make the Gnus IMAP experience much better).

> But having a line count may be sufficient as a start.  However,
> there is a big problem with caching.  If an incomplete article ends
> up in the asynchronous pre-fetcher, agent cache, user cache, etc, it
> will require some tinkering to invalidate that copy and force a
> re-query on the entire article.

I can deal with this, I think.  I looked at the code and it's not too
bad.  I just won't enter the article in the cache if it was fetched
partially.  Do you think this is OK?  When and if retrieval by MIME
part is done I can change this, but for now it seems like a good
compromise.

Ted