Re: [PATCH] Remove unecesssary invocations of org-mode in ox-publish

[Matt Lundin <mdl@imapmail.org>]

Nicolas Goaziou <mail@nicolasgoaziou.fr> writes:

> Hello,
>
> Matt Lundin <mdl@imapmail.org> writes:
>
>> Clearly, this is still very inadequate, but it is an improvement. I
>> would love to use the built in site-map functions, but they are simply
>> to slow for any larger projects.
>>
>> Could we do something like this to speed it up?
>>
>> (with-temp-buffer 
>>   (insert-file-contents file)
>>   (goto-char (point-min))
>>   (when (re-search-forward "^#\\+TITLE:" nil t)
>>     (org-element-at-point)))
>
> No, you also need to parse #+SETUPFILE: keywords. You could also get
> false positive within a verbatim block:
>
>  #+begin_example
>  #+title: something
>  #+end_example

> However, it is possible to write a specialized function to extract
> only #+TITLE.
>
> Another option is to cache results. See `org-publish-cache-set' and
> `org-publish-cache-get'.

Thanks for the helpful information. I think the cache would be a nice
way to go, especially if it were combined a timestamp check. E.g., only
files that have been updated since the last publishing should be queried
for titles; otherwise, use the cached file.

I notice that org-publish-find-title does cache the title, but AFAICT
this is never used, since org-publish-format-file-entry calls
org-publish-find-title with the reset argument. Perhaps we could add a
variable to make this optional in org-publish-format-file-entry. E.g., 

--8<---------------cut here---------------start------------->8---
(defun org-publish-format-file-entry (fmt file project-plist)
  (format-spec
   fmt
   `((?t . ,(org-publish-find-title file org-publish-find-title-use-cache))
[...]
--8<---------------cut here---------------end--------------->8---

A similar option could be added to the date function date function.

Would it be O.K. if I went ahead and implemented this?
Thanks,
Matt