e896369beb
When completing refs, several __git_refs() code paths list all the
refs from the refs/{heads,tags,remotes}/ hierarchy and then
__gitcomp_nl() iterates over those refs in a shell loop to filter out
refs not matching the current ref to be completed. This comes with a
considerable performance penalty when a repository contains a lot of
refs but the current ref can be uniquely completed or when only a
handful of refs match the current ref.
Reduce the number of iterations in __gitcomp_nl() from the number of
refs to the number of matching refs by specifying appropriate globbing
patterns to 'git for-each-ref' and 'git ls-remote' to list only those
refs that match the current ref to be completed. However, do so only
when the ref to match is explicitly given as parameter, because the
current word on the command line might contain a prefix like
'--option=' or 'branch..'. The __git_complete_refs() and
__git_complete_fetch_refspecs() helpers introduced previously in this
patch series already call __git_refs() specifying this current ref
parameter, so all their callsites, i.e. all places in the completion
script doing refs completion, can benefit from this optimization.
Furthermore, list only those symbolic and pseudo refs that match the
current ref to be completed. Though it doesn't matter at all in
itself performance-wise, it will allow us further significant
optimizations later in this series.
This speeds up refs completion considerably when there are a lot of
non-matching refs to be filtered out. Uniquely completing a branch in
a repository with 100k local branches, all packed, best of five:
On Linux, before:
$ time __git_complete_refs --cur=maste
real 0m0.831s
user 0m0.808s
sys 0m0.028s
After:
real 0m0.119s
user 0m0.104s
sys 0m0.008s
On Windows, before:
real 0m1.480s
user 0m1.031s
sys 0m0.060s
After:
real 0m0.377s
user 0m0.015s
sys 0m0.030s
Signed-off-by: SZEDER Gábor <szeder.dev@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 http://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.
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