Justin Tobler
d4c92e2ac9
In certain scenarios, Git handles writing blobs that exceed "core.bigFileThreshold" differently by streaming the object directly into a packfile. When there is an active ODB transaction, these blobs are streamed to the same packfile instead of using a separate packfile for each. If "pack.packSizeLimit" is configured and streaming another object causes the packfile to exceed the configured limit, the packfile is truncated back to the previous object and the object write is restarted in a new packfile. This works fine, but requires the fd being read from to save a checkpoint so it becomes possible to rewind the input source via seeking back to a known offset at the beginning. In a subsequent commit, blob streaming is converted to use `struct odb_write_stream` as a more generic input source instead of an fd which doesn't provide a mechanism for rewinding. For this use case though, rewinding the fd is not strictly necessary because the inflated size of the object is known and can be used to approximate whether writing the object would cause the packfile to exceed the configured limit prior to writing anything. These blobs written to the packfile are never deltified thus the size difference between what is written versus the inflated size is due to zlib compression. While this does prevent packfiles from being filled to the potential maximum is some cases, it should be good enough and still prevents the packfile from exceeding any configured limit. Use the inflated blob size to determine whether writing an object to a packfile will exceed the configured "pack.packSizeLimit". Signed-off-by: Justin Tobler <jltobler@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.adoc to get started, then see
Documentation/giteveryday.adoc for a useful minimum set of commands, and
Documentation/git-<commandname>.adoc 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.adoc
(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 to git+subscribe@vger.kernel.org (see https://subspace.kernel.org/subscribing.html for details). The mailing list archives are available at https://lore.kernel.org/git/, https://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