Re: [PATCH] don't use mmap() to hash files

From: Junio C Hamano <gitster@pobox.com>
Date: Feb 14, 2010, 03:14 UTC
Message-ID: <7v8wawy0ee.fsf@alter.siamese.dyndns.org>
In-Reply-To: <20100214021847.GA9704@dpotapov.dyndns.org>

Dmitry Potapov <dpotapov@gmail.com> writes:

Show 5 quoted lines

> My initial reaction was to write that the whole problem is due to abuse
> Git for the purposes that it was not intended. But then I decided to do
> some testing to see what impact it has. And, because I do not see any
> negative impact (in fact, slightly improve speed), and I decided to ask
> other people (who are interested in this patch) to do more testing.

Yes, I know, and I greatly appreciate it.

Later, we might want to split the codepath again to:

 (0) see if it is huge or small if we are not reading from pipe;

 (1) if we do not know the size or if it is moderately tiny, keep doing
     what your code does;

 (2) if we know we are reading something huge with known size, then have a
     loop to read-a-bit-compress-and-write-it-out-while-hashing, and
     finally rename the loose resulting object to the final name.  Or we
     may even want to do that into a new pack on its own.

but obviously all of that can come after this initial round ;-)