On August 20, 1998 at 10:58, Jason L Tibbitts III wrote:
e> Wilma doens't provide the cross linking. I sometimes wish it did, but I
e> haven't time to mess with it.. :-)
I don't think it can. If MHonArc had a way to have one central message-ID
to filename database that it could make the crosslinks from, then I think
this would happen automatically. But that's a bit out of Wilma's domain.
Cross archive linking is a known issue. It is possible to to create a
central message-id to filename database (like via DB_File). Some
issues arise providing such a feature:
o Locking central database from multiple processes modifying it.
The same technique can be used for archive locking, but then
you double the damage if MHonArc abnormally terminates.
o How to manage forward links. Detecting for cross-archive
references would be straight forward since modification to the
referenced message is not needed. However, linking back the
other way (ie. cross archive follow-up links) is more
problematic. It's possible, but performance will be an issue.
This implies that central database has to keep 3 sets of
information for each message-id:
- message-id => filename
- message-id => reference id list
- message-id => follow-up id list
o What to do if a message (same id) is added to more than one
archive. What gets stored as filename?
o Deleting a message gets more expensive since there can be
dependencies across multiple archives.
Some compromises can be made. For example, deleting a message only
updates the archive the deleted message is contained within. Then a
batch process can be used to periodically sync up the other archives.
The stickiest problem is the same message in multiple archives.
Earl Hood | University of California: Irvine
ehood(_at_)medusa(_dot_)acs(_dot_)uci(_dot_)edu | Electronic
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