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1406725b88
Add the necessary #includes and forward declarations to allow the header
file to pass the 'hdr-check' target.
Note that, since this header includes the commit-slab implementation
header file (indirectly via commit-slab.h), some of the commit-slab
inline functions (e.g contains_cache_at_peek()) will not compile without
the complete type of 'struct commit'. Hence, we replace the forward
declaration of 'struct commit' with the an #include of the 'commit.h'
header file.
It is possible, using the 'commit-slab-{decl,impl}.h' files, to avoid
this inclusion of the 'commit.h' header. Commit a9f1f1f9f8 ("commit-slab.h:
code split", 2018-05-19) separated the commit-slab interface from its
implementation, to allow for the definition of a public commit-slab data
structure. This enabled us to avoid including the commit-slab implementation
in a header file, which could result in the replication of the commit-slab
functions in each compilation unit in which it was included.
Indeed, if you compile with optimizations disabled, then run this script:
$ cat -n dup-static.sh
1 #!/bin/sh
2
3 nm $1 | grep ' t ' | cut -d' ' -f3 | sort | uniq -c |
4 sort -rn | grep -v ' 1'
$
$ ./dup-static.sh git | grep contains
24 init_contains_cache_with_stride
24 init_contains_cache
24 contains_cache_peek
24 contains_cache_at_peek
24 contains_cache_at
24 clear_contains_cache
$
you will find 24 copies of the commit-slab routines for the contains_cache.
Of course, when you enable optimizations again, these duplicate static
functions (mostly) disappear. Compiling with gcc at -O2, leaves two static
functions, thus:
$ nm commit-reach.o | grep contains_cache
0000000000000870 t contains_cache_at_peek.isra.1.constprop.6
$ nm ref-filter.o | grep contains_cache
00000000000002b0 t clear_contains_cache.isra.14
$
However, using a shared 'contains_cache' would result in all six of the
above functions as external public functions in the git binary. At present,
only three of these functions are actually called, so the trade-off
seems to favour letting the compiler inline the commit-slab functions.
Signed-off-by: Ramsay Jones <ramsay@ramsayjones.plus.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-.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.
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