From: Jonathan Nieder <jrnieder@gmail.com>
Date: Mon, 04 Oct 2010 19:16:57 GMT
Subject: Re: large files and low memory
Message-ID: <20101004191657.GC6466@burratino>
In-Reply-To: <AANLkTin-mbzt93DWtp71vYBEUcDLHgo=G-6zynT5NC_r@mail.gmail.com>

Shawn Pearce wrote:

> This change only removes the deflate copy.  But due to the SHA-1
> consistency issue I alluded to earlier, I think we're still making a
> full copy of the file in memory before we SHA-1 it or deflate it.

Hmm, I _think_ we still use mmap for that (which is why 748af44c needs
to compare the sha1 before and after).

But

 1) a one-pass calculation would presumably be a little (5%?) faster
 2) if there are smudge/clean filters or autocrlf involved, the
    cleaned-up file is backed by swap and this all becomes moot.