1Starting wich Suck-3.10.0, suck now supports a second type of killfiles.
2The original killfiles have not changed, and are still fully supported.
3
4In addition to the original killfiles, suck now supports killfiles
5that are processed by on data received from the XOVER command, not
6from the articles themselves.   The master killfile for this
7set is called "suckxover".
8
9Using the normal killfiles, suck would use the command XHDR to
10get the MessageID numbers for each group, then download each
11MessageID one at a time and check it against the killfiles, then
12go onto the next message.  To check against the killfiles, I'd
13first download the HEADER, check it, then if I needed to, download
14the BODY.   Because of this, I can't buffer commands and
15articles, so suck isn't very efficient.
16
17This changes under the new killfiles.  With these, suck now uses
18the XOVER command to get not only MessageIDs, but also the
19From:, Subject:, References:, Lines:, and ByteCount at the same
20time.  I can use this information to check against killfiles
21without downloading the header or the body of the article.
22To see which header fields your remote server supports via
23XOVER, run testhost remosthost -o.  If you need the -M command
24with suck, you'll probably need to run it as testhost remotehost
25-o -M.
26
27There are a few advantages to this approach.  The first is
28I can get the XOVER information for an entire group at a time,
29rather than one message at a time.  This should be more efficient
30on the server.   Plus, if you are using the BODYSIZE commands in
31killfiles, I don't have to download any of the message to kill it,
32saving time and bandwidth.  In addition, I don't have to download
33headers and bodies separate, and piece them back together.
34
35Also, when downloading messages, if there are no killfiles, there
36is pipelining code to make more efficient use of bandwidth.  Basically,
37I'm sending article commands 1 ahead of the one I'm receiving, so
38there should always be one waiting for me.
39
40If you don't use NRGROUPS, HEADER, BODY, and stick with the
41headers produced by the XOVER command, you should get quite
42a performance boost, just by renaming suckkillfile to
43suckxover.
44