Re: [Audacity-devel] Cache all blockfile data in memory

[Richard A. (audacity-help) <ri...@au...>]

Markus Meyer wrote:
> a user here has the crazy requirement that he wants to edit Audacity
> projects which are saved on network drives on a network which isn't
> exactly the fastest. When he plays audio, Audacity tries to read the
> blockfiles over the network, which is not fast enough, and so all sort
> of funny things happen, including stereo tracks where left and right
> channels are out of sync and general skipping of audio.
>
> Fortunately, the projects this user has are not too big (200 MB max), so
> it is feasible to load them into RAM and play them from RAM. So I
> implemented the attached patch, which does the following:

Kind of the obvious question: What happens if you run out of RAM, and
start hitting swap? and later, when you run out of swap?
I guess the first is just (an inefficient?) way of getting some local disk
cache when you can't otherwise, the latter is a problem.

A sideways thought, is there scope to enable a mode whereby the (local)
temp directory holds a copy of the project under edit, works there, and
audacity copies back to the saved project location on save / exit. This
would mean that you got the speed benfits of a local temp dir without the
hassle of manually copying projects to and fro.

I find myself saving projects to /tmp/ because it is a lot faster than
/home (it's on XFS / start of disk not reiserfs at the end), and then
having to re-save to /home to make space.

It may or may not help in your case because you might not have a temp dir
locally either, but I think it would help some users who start up, hit
record and it works in the temp, then save to their network drive and find
it doesn't work from there.

Richard