Re: multiple working directories for long-running builds (was: "git merge" merges too much!)

From: Jeff Epler <jepler@unpythonic.net>
Date: Dec 1, 2009, 22:25 UTC
Message-ID: <20091201222526.GB1926@unpythonic.net>
In-Reply-To: <20091201211830.GE11235@dpotapov.dyndns.org>

On Wed, Dec 02, 2009 at 12:18:30AM +0300, Dmitry Potapov wrote:

> AFAIK, "git archive" is cheaper than git clone. I do not say it is fast
> for huge project, but if you want to run a process such as clean build
> and test that takes a long time anyway, it does not add much to the
> total time.

If you want to keep a separate copy of your source tree in order to get consistent builds, "git archive" is not much cheaper in disk space or in time, at least on this unix system:

$ find orig -exec md5sum {} + > /dev/null 2>&1 # ensure hot cache $ time git clone orig temp-clone Initialized empty Git repository in /usr/local/jepler/src/temp-clone/.git/ 0.6 real 0.3 user 0.6 system $ time (GIT_DIR=orig/.git git archive --format tar --prefix temp-archive/ HEAD | tar xf -) 0.5 real 0.2 user 0.5 system $ du -s orig temp-clone temp-archive 41880 orig 14640 temp-clone # du excludes files already accounted for by 'orig' 14304 temp-archive

.. and the next run to bring temp-clone up to date can be even faster, since it's just 'git pull' and will only touch changed files.

Jeff