e7485601ca
When finishing a section we will potentially write an index that makes it more efficient to look up relevant blocks. The index records written will encode, for each block of the indexed section, what the offset of that block is as well as the last key of that block. Thus, the reader would iterate through the index records to find the first key larger or equal to the wanted key and then use the encoded offset to look up the desired block. When there are a lot of blocks to index though we may end up writing multiple index blocks, too. To not require a linear search across all index blocks we instead end up writing a multi-level index. Instead of referring to the block we are after, an index record may point to another index block. The reader will then access the highest-level index and follow down the chain of index blocks until it hits the sought-after block. It has been observed though that it is impossible to seek ref records of the last ref block when using a multi-level index. While the multi-level index exists and looks fine for most of the part, the highest-level index was missing an index record pointing to the last block of the next index. Thus, every additional level made more refs become unseekable at the end of the ref section. The root cause is that we are not flushing the last block of the current level once done writing the level. Consequently, it wasn't recorded in the blocks that need to be indexed by the next-higher level and thus we forgot about it. Fix this bug by flushing blocks after we have written all index records. Signed-off-by: Patrick Steinhardt <ps@pks.im> 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/, 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