Mark S Bilk posted on Wed, 10 Aug 2011 05:14:38 -0700 as excerpted: > (But KNode has no trouble using Astraweb. Is there more than one > protocol for requesting an article from a server? Will I have to dig > out Ethereal and spend a week decoding hex in network packets? Aggh!)
Yes. Messages can be requested by Message-ID or by per-server/per-group message sequence number. The former is a bit more work to implement in the client, but is global -- message-ids are the same no matter which server you get them from. This is the way nzb files work, etc. The latter is as mentioned per-server/per-group, with the server assigning increasing article numbers per group. This is easiest to track in terms of read messages, etc, but because each server and each group on the server has its own numbering, if a client tracks a message by message sequence number, switching servers means losing track of read-message info, etc. If the read-message tracking isn't reset at the same time and the new server has lower numbers, everything will appear already read to the client, until its read message tracking for that server is reset. If the new server has higher numbers, everything appears unread, as the client just sees a big gap in article sequence numbers. Pan actually makes use of both. Read-message-tracking is done via per- server newsrc standard format file, which uses article sequence numbers. However, since pan uses an nzb file for tracking its own task queue as well, I believe it actually fetches posts via message-id (tho it may fall- back to message-sequence-number in some instances, I don't know). It also stores them in cache via message-ID, which helps it manage multiple servers downloading at the same time, since if the article is already being downloaded in another thread (from the same server or a different one), a file by that message-id will already exist in cache so the other threads simply skip it. -- Duncan - List replies preferred. No HTML msgs. "Every nonfree program has a lord, a master -- and if you use the program, he is your master." Richard Stallman _______________________________________________ Pan-users mailing list Pan-users@nongnu.org https://lists.nongnu.org/mailman/listinfo/pan-users
