885ea73988
When git-last-modified(1) starts, it builds a list of all the paths
matching the pathspec it needs to find the last modifying commit for.
For example, every file and subdirectory listed by:
$ git last-modified -t --max-depth=0 -- src/
As it resolves a commit for each path during the revision walk, it drops
that path from the list.
To avoid diffing trees for every commit, Bloom filters are used when
available. For each remaining path, the commit's Bloom filter is checked
to see whether the commit changed that path. The Bloom filter says
either "no" or "maybe", and only in the latter case is the diff
calculated.
git-log(1) does this differently. It does not expand the pathspec but
checks the Bloom filter against the pathspec itself. This way, commits
not touching any path matching the pathspec can be discarded as a whole.
Apply this same check to git-last-modified(1). In a previous commit the
function revs_maybe_changed_in_bloom(), used by git-log(1), was made
public. Use this as a pre-filter in git-last-modified(1). After this
pre-filter, paths are still checked one-by-one to only find those which
don't have a "last commit" yet.
With `--show-trees` the list holds more than the paths matching the
pathspec. It also holds each parent tree entry, up to the root. Each of
those can resolve to a different commit. Thus for the pathspec "a/b/c",
the list will also hold "a" and "a/b".
When a commit touches "a/other", that commit could be the last commit
for "a", but revs_maybe_changed_in_bloom() would discard it, because it
doesn't match the full pathspec.
Instead, when `--show-trees` is given, use
revs_maybe_changed_in_bloom_with_parents(), which indicates the commit
maybe changed any of the paths leading up to the path in the pathspec.
Signed-off-by: Toon Claes <toon@iotcl.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