a941d5e395
Notes provide a fast lookup mechanism for data keyed by
sha1. This is ideal for caching certain operations, like
textconv filters.
This patch builds some infrastructure to make it simpler to
use notes trees as caches. In particular, caches:
1. don't have arbitrary commit messages. They store a
cache validity string in the commit, and clear the tree
when the cache validity string changes.
2. don't keep any commit history. The accumulated history
of a a cache is just useless cruft.
3. use a looser form of locking for ref updates. If two
processes try to write to the cache simultaneously, it
is OK if one overwrites the other, losing some changes.
It's just a cache, so we will just end up with an extra
miss.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
////////////////////////////////////////////////////////////////
GIT - the stupid content tracker
////////////////////////////////////////////////////////////////
"git" can mean anything, depending on your mood.
- random three-letter combination that is pronounceable, and not
actually used by any common UNIX command. The fact that it is a
mispronunciation of "get" may or may not be relevant.
- stupid. contemptible and despicable. simple. Take your pick from the
dictionary of slang.
- "global information tracker": you're in a good mood, and it actually
works for you. Angels sing, and a light suddenly fills the room.
- "goddamn idiotic truckload of sh*t": when it breaks
Git is a fast, scalable, distributed revision control system with an
unusually rich command set that provides both high-level operations
and full access to internals.
Git is an Open Source project covered by the GNU General Public License.
It was originally written by Linus Torvalds with help of a group of
hackers around the net. It is currently maintained by Junio C Hamano.
Please read the file INSTALL for installation instructions.
See Documentation/gittutorial.txt to get started, then see
Documentation/everyday.txt for a useful minimum set of commands, and
Documentation/git-commandname.txt for documentation of each command.
If git has been correctly installed, then the tutorial can also be
read with "man gittutorial" or "git help tutorial", and the
documentation of each command with "man git-commandname" or "git help
commandname".
CVS users may also want to read Documentation/gitcvs-migration.txt
("man gitcvs-migration" or "git help cvs-migration" if git is
installed).
Many Git online resources are accessible from http://git-scm.com/
including full documentation and Git related tools.
The user discussion and development of Git take place on the Git
mailing list -- everyone is welcome to post bug reports, feature
requests, comments and patches to git@vger.kernel.org. To subscribe
to the list, send an email with just "subscribe git" in the body to
majordomo@vger.kernel.org. The mailing list archives are available at
http://marc.theaimsgroup.com/?l=git and other archival sites.
The messages titled "A note from the maintainer", "What's in
git.git (stable)" and "What's cooking in git.git (topics)" and
the discussion following them on the mailing list give a good
reference for project status, development direction and
remaining tasks.