Re: [PATCH] Two issues with the gnus-registry

[Eric Abrahamsen <eric@ericabrahamsen.net>]

Eric Abrahamsen <eric@ericabrahamsen.net> writes:

> Eric Abrahamsen <eric@ericabrahamsen.net> writes:
>
>> Hi there,
>>
>> I'm using the gnus-registry in Gnorb to keep track of correspondences
>> between Gnus messages and Org headings, using a key on the registry
>> entries called 'gnorb-ids. This is meant to be a "precious" key, ie
>> entries with this key are not pruned. So far so good:
>>
>> (oref gnus-registry-db :precious) => (gnorb-ids mark)
>>
>> But the entries still do get pruned! I've just had tracked entries start
>> disappearing on me, and realized that they're getting pruned from the
>> registry when I save it. There appear to be two problems here:
>
> [...]
>
>> And I really don't know why the precious entries are getting pruned.
>> In a day or so, when I have more time, I'll test with a dummy registry,
>> with max-entries set to 10 and 'creation-time added to the precious
>> entries -- should make debugging easier.
>
> Okay, I got curious (frustrated) and tried this, and I just don't get
> it. `registry-prune' doesn't seem to work as advertised: first it
> deletes according to `registry-prune-soft-candidates', which preserves
> precious entries, and then it deletes according to
> `registry-prune-hard-candidates', which doesn't.p
>
> The second pass unconditionally caps the registry length at 90% of
> `gnus-registry-max-entries', without consulting the entries' precious
> status at all.
>
> The `prune-needed' local variable also appears unused.

Given the commentary in registry.el, I wonder if the whole pruning
arrangement actually never quite got finished:

;; The user decides which fields are "precious", F2 for example.  At
;; PRUNE TIME (when the :prune-function is called), the registry will
;; trim any entries without the F2 field until the size is :max-soft
;; or less.  No entries with the F2 field will be removed at PRUNE
;; TIME.

It looks like there's supposed to be a :prune-function slot on registry
objects, and presumably the Gnus registry would have a prune function
that worked more like what the comments above outline.

I'd be happy to help work on this, with a little direction...

Eric