Re: Time to compile

Fran=E7ois Pinard wrote:

> [Bram Moolenaar]
>=20
> >Derek Teaney wrote:
>=20
> >> I have a list of about 40 files and it takes quite some time (12 s)=20
> >> to decide what to do compile.  Would 400 files then take 2 minutes?
>=20
> > A-A-P computes a checksum to find out if the file contents has=20
> > changed.  If your processor is slow this may take a while.  I have=20
> > worked with Aap and very many files without big delays.  It does=20
> > depend on the speed of your machine, of course.  Only checking=20
> > timestamps will be faster, but less accurate.  And after doing "touch=
=20
> > file" a file may seem outdated, causing a lot of work to be done even=
=20
> > when its contents didn't actually change.  That's wasting time then.
>=20
> Just an idea.  Could checksums be computed only if timestamps
> differ (regardless of ordering of timestamps)?  Size might also be=20
> checked for a bit more safety, when timestamps are identical.  That=20
> might speed up things for big projects, without adverse effects in=20
> practice.

Timestamps on files often have an accuracy of one second only.  It's
very well possible today to change a file several times within a second,
e.g. when running a shell script to compile two versions with different
features.  I don't really want to make Aap less reliable for the sake of
performance.

--=20
~
~
~
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