From mboxrd@z Thu Jan  1 00:00:00 1970
From: Nicolas Goaziou <mail@nicolasgoaziou.fr>
Subject: Re: Bug: Caching org-publish-find-date [8.2.10 (release_8.2.10 @
 /opt/emacs/lisp/org/)]
Date: Wed, 27 Dec 2017 23:48:57 +0100
Message-ID: <87r2rfyeg6.fsf@nicolasgoaziou.fr>
References: <CADjgTRzfekmjgsdVY3+bjZ0AS9qHKD2X6=y+F6EgZoLxbqNArg@mail.gmail.com>
Mime-Version: 1.0
Content-Type: text/plain
Return-path: <emacs-orgmode-bounces+geo-emacs-orgmode=m.gmane.org@gnu.org>
Received: from eggs.gnu.org ([2001:4830:134:3::10]:52089)
	by lists.gnu.org with esmtp (Exim 4.71)
	(envelope-from <mail@nicolasgoaziou.fr>) id 1eUKVS-0000nM-Hl
	for emacs-orgmode@gnu.org; Wed, 27 Dec 2017 17:49:03 -0500
Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71)
	(envelope-from <mail@nicolasgoaziou.fr>) id 1eUKVR-0005ol-Jd
	for emacs-orgmode@gnu.org; Wed, 27 Dec 2017 17:49:02 -0500
Received: from relay4-d.mail.gandi.net ([2001:4b98:c:538::196]:58613)
	by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32)
	(Exim 4.71) (envelope-from <mail@nicolasgoaziou.fr>)
	id 1eUKVR-0005nW-A0
	for emacs-orgmode@gnu.org; Wed, 27 Dec 2017 17:49:01 -0500
In-Reply-To: <CADjgTRzfekmjgsdVY3+bjZ0AS9qHKD2X6=y+F6EgZoLxbqNArg@mail.gmail.com>
	(Lorenzo Bolla's message of "Wed, 27 Dec 2017 16:54:49 +0000")
List-Id: "General discussions about Org-mode." <emacs-orgmode.gnu.org>
List-Unsubscribe: <https://lists.gnu.org/mailman/options/emacs-orgmode>,
	<mailto:emacs-orgmode-request@gnu.org?subject=unsubscribe>
List-Archive: <http://lists.gnu.org/archive/html/emacs-orgmode/>
List-Post: <mailto:emacs-orgmode@gnu.org>
List-Help: <mailto:emacs-orgmode-request@gnu.org?subject=help>
List-Subscribe: <https://lists.gnu.org/mailman/listinfo/emacs-orgmode>,
	<mailto:emacs-orgmode-request@gnu.org?subject=subscribe>
Errors-To: emacs-orgmode-bounces+geo-emacs-orgmode=m.gmane.org@gnu.org
Sender: "Emacs-orgmode"
	<emacs-orgmode-bounces+geo-emacs-orgmode=m.gmane.org@gnu.org>
To: Lorenzo Bolla <lbolla@gmail.com>
Cc: emacs-orgmode@gnu.org

Hello,

Lorenzo Bolla <lbolla@gmail.com> writes:

> When using `org-publish-project` I noticed that generating a sitemap
> sorted (anti-)chronologically is very slow. It turns out that the
> slowness is due to the sorting of sitemap entries, which calls
> `org-publish-find-date` during the comparison. But
> `org-publish-find-date` is not cached therefore it is called over and
> over for each file during the sorting process.
> By contrast, `org-publish-find-title` is cached and sorting
> alphabetically is faster.
>
> To test this assumption, I've modified `ox-publish.el` to cache
>    `org-publish-find-date`, too, obtaining a substantial speed-up:
>
>    (defun org-publish-find-date (file)
>      (or
>       (org-publish-cache-get-file-property file :date nil t)
>       (let ((date (org-publish-find-date-uncached file)))
>         (org-publish-cache-set-file-property file :date date)
>         date)))
>
>    (defun org-publish-find-date-uncached (file)
>      "Find the date of FILE in project.
>    This function assumes FILE is either a directory or an Org file.
>    If FILE is an Org file and provides a DATE keyword use it.  In
>    any other case use the file system's modification time.  Return
>    time in `current-time' format."
>    ...
>
> Is there a reason why we should not cache the date of a file, in the
> same way as we cache its title?

That's post-mature optimization. When only cache results of a function
when it is reported as horribly slow.

I added a cache for `org-publish-find-date' in master branch. Thank you.

Regards,

-- 
Nicolas Goaziou