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Re: Thinking about changed buffers
From: |
Lars Magne Ingebrigtsen |
Subject: |
Re: Thinking about changed buffers |
Date: |
Mon, 28 Mar 2016 21:27:28 +0200 |
User-agent: |
Gnus/5.13 (Gnus v5.13) Emacs/25.1.50 (gnu/linux) |
Stefan Monnier <address@hidden> writes:
>> if (BUF_SAVE_MODIFF (buf) == BUF_MODIFF (buf))
>> return Qnil;
>
> This test basically never succeeds except when we already know the file
> in not modified.
It's to avoid having the hashing function being called several times in
a row if you happen to have the "original size" in the buffer. It's
what makes this hash only being called the first time per ... time. :-)
>> we can short circuit the hash calculation like, almost always. It would
>> only be necessary (the first time per ... time) the buffer reaches the
>> same size that it used to be.
>
> Still seems problematic if your 5 year old takes 2.7s to compute it on
> a 1GB file. You don't want to freeze for 2s in the normal course of
> editing just because you happen to cross the "original size" threshold.
Yeah, I don't see any way around that.
--
(domestic pets only, the antidote for overdose, milk.)
bloggy blog: http://lars.ingebrigtsen.no
Re: Thinking about changed buffers, Florian Weimer, 2016/03/29
Re: Thinking about changed buffers, Phillip Lord, 2016/03/29