org-persist cache for remote files (was: org-persist)

[Ihor Radchenko <yantar92@gmail.com>]

Lele Gaifax <lele@metapensiero.it> writes:

> Digging down, I found that it was due to the persistent cache, that contained
> several entries about remote (Tramp) documents: upon closing Emacs, the
> org-persist-gc function is triggered, and the index is traversed to remove
> dangling entries, performing a file-exist-p on each filename. For remote
> files, that obviously mean prompting for the remote password (when the
> ssh-agent does not carry it) or spending a considerable time in the network
> round trip.

Thanks for reporting! I am not using tramp regularly and I did not think
about this use case.

> I wonder if there is some mechanism I could use to either prevent caching of
> non-local documents or to avoid the check on existence in the org-persist-gc.

I can easily make a change that always garbage-collect non-local
documents without trying to connect to remote server. This can be one
solution of your problem. However, I am not sure if it is the best
solution.

May I know more about your use cases? Do you frequently open large
remote Org files? If you do, trashing their cache may not be optimal.
Maybe we should better make this a user option?

Or we can go a different route and just not garbage collect remote files
until cache gets too large.

WDYT?

Best,
Ihor