db40e3c92b
When calling `try_partial_reuse()`, the (sole) caller from the function `reuse_partial_packfile_from_bitmap_1()` has to translate its bit position to a pack position. In the MIDX bitmap case, the caller translates from the bit position, to a position in the MIDX's pseudo-pack order (with `pack_pos_to_midx()`), then get a pack offset (with `nth_midxed_offset()`) before finally working backwards to get the pack position in the source pack by calling `offset_to_pack_pos()`. In the non-MIDX bitmap case, we can use the bit position as the pack position directly (see the comment at the beginning of the `reuse_partial_packfile_from_bitmap_1()` function for why). In either case, the first thing that `try_partial_reuse()` does after being called is determine the offset of the object at the given pack position by calling `pack_pos_to_offset()`. But we already have that information in the MIDX case! Avoid re-computing that information by instead passing it in. In the MIDX case, we already have that information stored. In the non-MIDX case, the call to `pack_pos_to_offset()` moves from the function `try_partial_reuse()` to its caller. In total, we'll save one call to `pack_pos_to_offset()` when processing MIDX bitmaps. (On my machine, there is a slight speed-up on the order of ~2ms, but it is within the margin of error over 10 runs, so I think you'd have to have a truly gigantic repository to confidently measure any significant improvement here). Signed-off-by: Taylor Blau <me@ttaylorr.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 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