4cea1ce0f6
The loose objects cache is filled one subdirectory at a time as needed. It is stored in an oid_array, which has to be resorted after each add operation. So when querying a wide range of objects, the partially filled array needs to be resorted up to 255 times, which takes over 100 times longer than sorting once. Use one oid_array for each subdirectory. This ensures that entries have to only be sorted a single time. It also avoids eight binary search steps for each cache lookup as a small bonus. The cache is used for collision checks for the log placeholders %h, %t and %p, and we can see the change speeding them up in a repository with ca. 100 objects per subdirectory: $ git count-objects 26733 objects, 68808 kilobytes Test HEAD^ HEAD -------------------------------------------------------------------- 4205.1: log with %H 0.51(0.47+0.04) 0.51(0.49+0.02) +0.0% 4205.2: log with %h 0.84(0.82+0.02) 0.60(0.57+0.03) -28.6% 4205.3: log with %T 0.53(0.49+0.04) 0.52(0.48+0.03) -1.9% 4205.4: log with %t 0.84(0.80+0.04) 0.60(0.59+0.01) -28.6% 4205.5: log with %P 0.52(0.48+0.03) 0.51(0.50+0.01) -1.9% 4205.6: log with %p 0.85(0.78+0.06) 0.61(0.56+0.05) -28.2% 4205.7: log with %h-%h-%h 0.96(0.92+0.03) 0.69(0.64+0.04) -28.1% Reported-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com> Signed-off-by: Rene Scharfe <l.s.r@web.de> Signed-off-by: Junio C Hamano <gitster@pobox.com>
Git - fast, scalable, distributed revision control system
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 version 2 (some parts of it are under different licenses, compatible with the GPLv2). It was originally written by Linus Torvalds with help of a group of hackers around the net.
Please read the file INSTALL for installation instructions.
Many Git online resources are accessible from https://git-scm.com/ including full documentation and Git related tools.
See Documentation/gittutorial.txt to get started, then see
Documentation/giteveryday.txt for a useful minimum set of commands, and
Documentation/git-.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).
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 (read Documentation/SubmittingPatches for instructions on patch submission). 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 https://public-inbox.org/git/, http://marc.info/?l=git and other archival sites.
Issues which are security relevant should be disclosed privately to the Git Security mailing list git-security@googlegroups.com.
The maintainer frequently sends the "What's cooking" reports that list the current status of various development topics to the mailing list. The discussion following them give a good reference for project status, development direction and remaining tasks.
The name "git" was given by Linus Torvalds when he wrote the very first version. He described the tool as "the stupid content tracker" and the name as (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