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From: prj@po.cwru.edu (Paul Jarc)
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Subject: Re: "Fixing up" gnus - (how hard is this?). (was Re: (provide 'nnmaildir))
Date: 18 Oct 2000 11:13:24 -0400
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Rob Browning <rlb@cs.utexas.edu> writes:
> I'd like to go even farther and have gnus write out log/journal
> snippets every time you take an action, or have it do atomic writes of
> group state info (using link/unlink tricks) so that it would be very
> hard to corrupt your state records.

nnmaildir's been doing that since the 2000-09-03 release. :)  But use
rename(), not link()/unlink(), for appropriate atomicity.  It's not so
critical when there are no concurrent readers, but it still saves you
a system call.  I haven't checked the Emacs sources, but I'm assuming
(rename-file) uses rename() when ok-if-already-exists is non-nil.

> As an added IMO *way-cool* feature, I wonder if it would be possible
> to define an interface that was both elisp and scheme friendly, and
> better yet, use a backend storage format that was too (i.e. have the
> forms where you store the state stick to a common "form" subset that
> both parsers can handle).

Hmm... nnmaildir's state files are non-Lisp text, parsed manually.  I
suppose (read)ing Lisp expressions would probably be faster, though.
I hadn't thought of that.


paul