[plug] File Synchronize - Open Source

[James Devenish]

Hi,

In message <20040825151733.GH21943 at cp.yi.org>
on Wed, Aug 25, 2004 at 11:17:33PM +0800, Cameron Patrick wrote:
> Aha.  Well, now I have you cowering in the corner facing unspecified
> implements of prescriptive grammarian doom,

:) [Of course, my extremely valid excuse for poor writing is that I was
distracted by studying for a test.]

> Is there an easy way to get unison to not stat() every file in the
> replica?  I have a multi-hundred-MB replica (a subset of my e-mail, in
> Maildir format) consisting of many thousands of files which I
> synchronise regularly between the mail server and my laptop.  It takes
> quite a while (>1 minute if the results aren't in cache) for unison to
> look for changes on each machine.
> One of the guarantees that the Maildir format makes is that file
> contents are never altered without the file name also changing.

So, what you really want is an option along the lines of "look for new
files but do not consider looking for modified files"? I'm not sure that
such an option is provided in v2.9.1 (though in the current beta I guess
you'd use `-fastcheck true -pretendwin` to achieve this effect). I guess
raw rsync wins in this case.

> In fact, it can do better: if a directory mtime hasn't changed, we can
> guarantee that nothing in the directory has changed -- and a lot of
> the time, nothing will have changed in most folders, so this should be
> a big win.

I assume that the other guarantee in this situation is that
the directory contains no subdirectories. I can't think of
any optimisation in unison for such a case.