2b6070ac4c
If we want unpack and write a loose object using "write_loose_object", we have to feed it with a buffer with the same size of the object, which will consume lots of memory and may cause OOM. This can be improved by feeding data to "stream_loose_object()" in a stream. Add a new function "stream_loose_object()", which is a stream version of "write_loose_object()" but with a low memory footprint. We will use this function to unpack large blob object in later commit. Another difference with "write_loose_object()" is that we have no chance to run "write_object_file_prepare()" to calculate the oid in advance. In "write_loose_object()", we know the oid and we can write the temporary file in the same directory as the final object, but for an object with an undetermined oid, we don't know the exact directory for the object. Still, we need to save the temporary file we're preparing somewhere. We'll do that in the top-level ".git/objects/" directory (or whatever "GIT_OBJECT_DIRECTORY" is set to). Once we've streamed it we'll know the OID, and will move it to its canonical path. "freshen_packed_object()" or "freshen_loose_object()" will be called inside "stream_loose_object()" after obtaining the "oid". After the temporary file is written, we wants to mark the object to recent and we may find that where indeed is already the object. We should remove the temporary and do not leave a new copy of the object. Helped-by: René Scharfe <l.s.r@web.de> Helped-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com> Helped-by: Jiang Xin <zhiyou.jx@alibaba-inc.com> Signed-off-by: Han Xin <chiyutianyi@gmail.com> Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com> 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-<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).
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 and Documentation/CodingGuidelines).
Those wishing to help with error message, usage and informational message
string translations (localization l10) should see po/README.md
(a po file is a Portable Object file that holds the translations).
To subscribe to the list, send an email with just "subscribe git" in the body to majordomo@vger.kernel.org (not the Git list). The mailing list archives are available at https://lore.kernel.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