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Rafael Silva a643157d5a repack: avoid loosening promisor objects in partial clones
When `git repack -A -d` is run in a partial clone, `pack-objects`
is invoked twice: once to repack all promisor objects, and once to
repack all non-promisor objects. The latter `pack-objects` invocation
is with --exclude-promisor-objects and --unpack-unreachable, which
loosens all objects unused during this invocation. Unfortunately,
this includes promisor objects.

Because the -d argument to `git repack` subsequently deletes all loose
objects also in packs, these just-loosened promisor objects will be
immediately deleted. However, this extra disk churn is unnecessary in
the first place.  For example, in a newly-cloned partial repo that
filters all blob objects (e.g. `--filter=blob:none`), `repack` ends up
unpacking all trees and commits into the filesystem because every
object, in this particular case, is a promisor object. Depending on
the repo size, this increases the disk usage considerably: In my copy
of the linux.git, the object directory peaked 26GB of more disk usage.

In order to avoid this extra disk churn, pass the names of the promisor
packfiles as --keep-pack arguments to the second invocation of
`pack-objects`. This informs `pack-objects` that the promisor objects
are already in a safe packfile and, therefore, do not need to be
loosened.

For testing, we need to validate whether any object was loosened.
However, the "evidence" (loosened objects) is deleted during the
process which prevents us from inspecting the object directory.
Instead, let's teach `pack-objects` to count loosened objects and
emit via trace2 thus allowing inspecting the debug events after the
process is finished. This new event is used on the added regression
test.

Lastly, add a new perf test to evaluate the performance impact
made by this changes (tested on git.git):

     Test          HEAD^                 HEAD
     ----------------------------------------------------------
     5600.3: gc    134.38(41.93+90.95)   7.80(6.72+1.35) -94.2%

For a bigger repository, such as linux.git, the improvement is
even bigger:

     Test          HEAD^                     HEAD
     -------------------------------------------------------------------
     5600.3: gc    6833.00(918.07+3162.74)   268.79(227.02+39.18) -96.1%

These improvements are particular big because every object in the
newly-cloned partial repository is a promisor object.

Reported-by: SZEDER Gábor <szeder.dev@gmail.com>
Helped-by: Jeff King <peff@peff.net>
Helped-by: Jonathan Tan <jonathantanmy@google.com>
Signed-off-by: Rafael Silva <rafaeloliveira.cs@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-04-28 13:36:13 +09:00
.github cmake(install): include vcpkg dlls 2021-03-29 13:49:04 -07:00
Documentation The eighth batch 2021-04-08 13:23:26 -07:00
block-sha1 block-sha1: drop trailing semicolon from macro definition 2021-03-17 10:20:01 -07:00
builtin repack: avoid loosening promisor objects in partial clones 2021-04-28 13:36:13 +09:00
ci Merge branch 'tb/pack-revindex-on-disk' 2021-02-12 14:21:04 -08:00
compat Merge branch 'jh/simple-ipc' 2021-04-02 14:43:14 -07:00
contrib Merge branch 'js/cmake-vsbuild' 2021-04-07 16:54:08 -07:00
ewah use CALLOC_ARRAY 2021-03-13 16:00:09 -08:00
git-gui Merge https://github.com/prati0100/git-gui 2021-03-04 12:38:50 -08:00
gitk-git
gitweb
mergetools mergetools/vimdiff: add vimdiff1 merge tool variant 2021-02-23 11:37:13 -08:00
negotiator use CALLOC_ARRAY 2021-03-13 16:00:09 -08:00
perl git-send-email: Respect core.hooksPath setting 2021-03-23 15:02:52 -07:00
po l10n: zh_CN: for git v2.31.0 l10n round 1 and 2 2021-03-15 00:05:25 +08:00
ppc
refs use CALLOC_ARRAY 2021-03-13 16:00:09 -08:00
sha1collisiondetection@855827c583
sha1dc
sha256
t repack: avoid loosening promisor objects in partial clones 2021-04-28 13:36:13 +09:00
templates
trace2
xdiff
.cirrus.yml
.clang-format
.editorconfig
.gitattributes
.gitignore
.gitmodules
.mailmap Add entry for Ramkumar Ramachandra 2021-03-08 09:56:34 -08:00
.travis.yml
.tsan-suppressions
CODE_OF_CONDUCT.md
COPYING
GIT-VERSION-GEN Git 2.31.1 2021-03-26 14:49:41 -07:00
INSTALL INSTALL: note on using Asciidoctor to build doc 2021-03-19 10:49:20 -07:00
LGPL-2.1
Makefile Merge branch 'ab/make-tags-quiet' 2021-04-08 13:23:26 -07:00
README.md
RelNotes Git 2.31.1 2021-03-26 14:49:41 -07:00
SECURITY.md SECURITY: describe how to report vulnerabilities 2021-03-27 15:13:02 -07:00
abspath.c
aclocal.m4
add-interactive.c Merge branch 'rs/xcalloc-takes-nelem-first' 2021-03-19 15:25:39 -07:00
add-interactive.h
add-patch.c
advice.c
advice.h
alias.c
alias.h
alloc.c
alloc.h
apply.c Merge branch 'mt/parallel-checkout-part-1' 2021-04-02 14:43:14 -07:00
apply.h
archive-tar.c use CALLOC_ARRAY 2021-03-13 16:00:09 -08:00
archive-zip.c
archive.c Merge branch 'ab/read-tree' 2021-03-30 14:35:37 -07:00
archive.h archive: expand only a single %(describe) per archive 2021-03-11 13:22:44 -08:00
attr.c Merge branch 'jk/open-dotgitx-with-nofollow' 2021-03-22 14:00:22 -07:00
attr.h
banned.h
base85.c
bisect.c use CALLOC_ARRAY 2021-03-13 16:00:09 -08:00
bisect.h
blame.c use CALLOC_ARRAY 2021-03-13 16:00:09 -08:00
blame.h
blob.c
blob.h
bloom.c use CALLOC_ARRAY 2021-03-13 16:00:09 -08:00
bloom.h
branch.c
branch.h
builtin.h
bulk-checkin.c use CALLOC_ARRAY 2021-03-13 16:00:09 -08:00
bulk-checkin.h
bundle.c
bundle.h
cache-tree.c use CALLOC_ARRAY 2021-03-13 16:00:09 -08:00
cache-tree.h
cache.h Merge branch 'mt/parallel-checkout-part-1' 2021-04-02 14:43:14 -07:00
chdir-notify.c
chdir-notify.h
check-builtins.sh
check_bindir
checkout.c
checkout.h
chunk-format.c chunk-format: restore duplicate chunk checks 2021-02-18 13:38:16 -08:00
chunk-format.h chunk-format: create read chunk API 2021-02-18 13:38:16 -08:00
color.c
color.h
column.c
column.h
combine-diff.c use CALLOC_ARRAY 2021-03-13 16:00:09 -08:00
command-list.txt
commit-graph.c Merge branch 'ds/commit-graph-generation-config' 2021-03-22 14:00:23 -07:00
commit-graph.h commit-graph: use config to specify generation type 2021-02-25 15:10:41 -08:00
commit-reach.c use CALLOC_ARRAY 2021-03-13 16:00:09 -08:00
commit-reach.h
commit-slab-decl.h
commit-slab-impl.h
commit-slab.h
commit.c Merge branch 'cm/rebase-i-fixup-amend-reword' 2021-03-26 14:59:03 -07:00
commit.h Merge branch 'cm/rebase-i-fixup-amend-reword' 2021-03-26 14:59:03 -07:00
common-main.c
config.c use CALLOC_ARRAY 2021-03-13 16:00:09 -08:00
config.h
config.mak.dev
config.mak.in
config.mak.uname Merge branch 'jh/simple-ipc' 2021-04-02 14:43:14 -07:00
configure.ac
connect.c Merge branch 'jt/clone-unborn-head' 2021-02-17 17:21:40 -08:00
connect.h
connected.c
connected.h
convert.c Merge branch 'jh/simple-ipc' 2021-04-02 14:43:14 -07:00
convert.h convert: add classification for conv_attrs struct 2021-03-18 13:56:40 -07:00
copy.c
credential.c
credential.h
csum-file.c csum-file: make hashwrite() more readable 2021-03-26 14:32:45 -07:00
csum-file.h
ctype.c
daemon.c Merge branch 'rs/daemon-sanitize-dir-sep' 2021-04-08 13:23:26 -07:00
date.c
decorate.c use CALLOC_ARRAY 2021-03-13 16:00:09 -08:00
decorate.h
delta-islands.c
delta-islands.h
delta.h
detect-compiler
diff-delta.c
diff-lib.c fsmonitor: add assertion that fsmonitor is valid to check_removed 2021-03-18 13:31:13 -07:00
diff-merges.c
diff-merges.h
diff-no-index.c
diff.c use CALLOC_ARRAY 2021-03-13 16:00:09 -08:00
diff.h Merge branch 'jc/diffcore-rotate' 2021-02-25 16:43:30 -08:00
diffcore-break.c
diffcore-delta.c
diffcore-order.c
diffcore-pickaxe.c
diffcore-rename.c Merge branch 'en/ort-perf-batch-9' 2021-04-08 13:23:26 -07:00
diffcore-rotate.c diff: --{rotate,skip}-to=<path> 2021-02-16 09:30:42 -08:00
diffcore.h Merge branch 'en/ort-perf-batch-9' 2021-04-08 13:23:26 -07:00
dir-iterator.c
dir-iterator.h
dir.c Merge branch 'jk/open-dotgitx-with-nofollow' 2021-03-22 14:00:22 -07:00
dir.h exclude: add flags parameter to add_patterns() 2021-02-16 09:41:33 -08:00
editor.c
entry.c Merge branch 'mt/parallel-checkout-part-1' 2021-04-02 14:43:14 -07:00
entry.h entry: add checkout_entry_ca() taking preloaded conv_attrs 2021-03-23 10:34:05 -07:00
environment.c
environment.h
exec-cmd.c
exec-cmd.h
fetch-negotiator.c
fetch-negotiator.h
fetch-pack.c Merge branch 'll/clone-reject-shallow' 2021-04-08 13:23:25 -07:00
fetch-pack.h builtin/clone.c: add --reject-shallow option 2021-04-01 12:58:58 -07:00
fmt-merge-msg.c use CALLOC_ARRAY 2021-03-13 16:00:09 -08:00
fmt-merge-msg.h
fsck.c fetch-pack: use new fsck API to printing dangling submodules 2021-03-28 19:03:10 -07:00
fsck.h fetch-pack: use new fsck API to printing dangling submodules 2021-03-28 19:03:10 -07:00
fsmonitor.c Merge branch 'jh/fsmonitor-prework' 2021-03-19 15:25:37 -07:00
fsmonitor.h fsmonitor: add assertion that fsmonitor is valid to check_removed 2021-03-18 13:31:13 -07:00
fuzz-commit-graph.c
fuzz-pack-headers.c
fuzz-pack-idx.c
generate-cmdlist.sh
generate-configlist.sh
gettext.c Merge branch 'ab/detox-gettext-tests' 2021-02-10 14:48:33 -08:00
gettext.h
git-add--interactive.perl
git-archimport.perl
git-bisect.sh
git-compat-util.h Merge branch 'jk/open-dotgitx-with-nofollow' 2021-03-22 14:00:22 -07:00
git-cvsexportcommit.perl
git-cvsimport.perl
git-cvsserver.perl
git-difftool--helper.sh mergetool: break setup_tool out into separate initialization function 2021-02-09 14:09:16 -08:00
git-filter-branch.sh filter-branch: drop $_x40 glob 2021-03-10 14:16:58 -08:00
git-instaweb.sh
git-merge-octopus.sh
git-merge-one-file.sh
git-merge-resolve.sh
git-mergetool--lib.sh Merge branch 'sh/mergetool-hideresolved' 2021-02-17 17:21:41 -08:00
git-mergetool.sh mergetool: do not enable hideResolved by default 2021-03-13 15:30:29 -08:00
git-p4.py Merge branch 'dl/p4-encode-after-kw-expansion' into maint 2021-02-08 14:05:54 -08:00
git-quiltimport.sh
git-rebase--preserve-merges.sh
git-request-pull.sh
git-send-email.perl git-send-email: Respect core.hooksPath setting 2021-03-23 15:02:52 -07:00
git-sh-i18n.sh
git-sh-setup.sh
git-submodule.sh
git-svn.perl
git-web--browse.sh
git.c Merge branch 'tb/precompose-prefix-too' 2021-02-12 14:21:04 -08:00
git.rc
gpg-interface.c gpg-interface: remove other signature headers before verifying 2021-02-10 23:35:42 -08:00
gpg-interface.h gpg-interface: improve interface for parsing tags 2021-02-10 23:35:42 -08:00
graph.c
graph.h
grep.c Merge branch 'ab/grep-pcre2-allocfix' 2021-03-22 14:00:23 -07:00
grep.h grep/pcre2: move back to thread-only PCREv2 structures 2021-02-17 16:32:19 -08:00
hash-lookup.c
hash-lookup.h
hash.h
hashmap.c use CALLOC_ARRAY 2021-03-13 16:00:09 -08:00
hashmap.h
help.c
help.h
hex.c
http-backend.c use CALLOC_ARRAY 2021-03-13 16:00:09 -08:00
http-fetch.c http-fetch: allow custom index-pack args 2021-02-22 12:07:40 -08:00
http-push.c lookup_unknown_object(): take a repository argument 2021-04-13 13:18:46 -07:00
http-walker.c
http.c Merge branch 'cs/http-use-basic-after-failed-negotiate' 2021-03-30 14:35:37 -07:00
http.h http: allow custom index-pack args 2021-02-22 12:07:40 -08:00
ident.c
imap-send.c use CALLOC_ARRAY 2021-03-13 16:00:09 -08:00
iterator.h
json-writer.c
json-writer.h
khash.h
kwset.c
kwset.h
levenshtein.c
levenshtein.h
line-log.c use CALLOC_ARRAY 2021-03-13 16:00:09 -08:00
line-log.h
line-range.c use CALLOC_ARRAY 2021-03-13 16:00:09 -08:00
line-range.h
linear-assignment.c
linear-assignment.h
list-objects-filter-options.c
list-objects-filter-options.h
list-objects-filter.c use CALLOC_ARRAY 2021-03-13 16:00:09 -08:00
list-objects-filter.h
list-objects.c
list-objects.h
list.h
ll-merge.c use CALLOC_ARRAY 2021-03-13 16:00:09 -08:00
ll-merge.h
lockfile.c
lockfile.h
log-tree.c format-patch: allow a non-integral version numbers 2021-03-23 12:49:47 -07:00
log-tree.h
ls-refs.c Merge branch 'jt/clone-unborn-head' 2021-02-17 17:21:40 -08:00
ls-refs.h
mailinfo.c
mailinfo.h
mailmap.c Merge branch 'jk/open-dotgitx-with-nofollow' 2021-03-22 14:00:22 -07:00
mailmap.h
match-trees.c
mem-pool.c mem-pool: drop trailing semicolon from macro definition 2021-03-17 10:20:16 -07:00
mem-pool.h
merge-blobs.c
merge-blobs.h
merge-ort-wrappers.c
merge-ort-wrappers.h
merge-ort.c Merge branch 'en/ort-perf-batch-9' 2021-04-08 13:23:26 -07:00
merge-ort.h
merge-recursive.c Merge branch 'ab/read-tree' 2021-03-30 14:35:37 -07:00
merge-recursive.h
merge.c
mergesort.c
mergesort.h
midx.c Merge branch 'tb/reverse-midx' 2021-04-08 13:23:25 -07:00
midx.h pack-revindex: write multi-pack reverse indexes 2021-04-01 13:07:37 -07:00
name-hash.c use CALLOC_ARRAY 2021-03-13 16:00:09 -08:00
notes-cache.c
notes-cache.h
notes-merge.c use CALLOC_ARRAY 2021-03-13 16:00:09 -08:00
notes-merge.h
notes-utils.c use CALLOC_ARRAY 2021-03-13 16:00:09 -08:00
notes-utils.h
notes.c use CALLOC_ARRAY 2021-03-13 16:00:09 -08:00
notes.h
object-file.c use CALLOC_ARRAY 2021-03-13 16:00:09 -08:00
object-name.c
object-store.h packfile: add kept-pack cache for find_kept_pack_entry() 2021-02-22 23:30:52 -08:00
object.c lookup_unknown_object(): take a repository argument 2021-04-13 13:18:46 -07:00
object.h lookup_unknown_object(): take a repository argument 2021-04-13 13:18:46 -07:00
oid-array.c
oid-array.h
oidmap.c
oidmap.h
oidset.c
oidset.h
pack-bitmap-write.c
pack-bitmap.c Merge branch 'ps/pack-bitmap-optim' 2021-04-07 16:54:09 -07:00
pack-bitmap.h rev-list: add --disk-usage option for calculating disk usage 2021-02-11 09:57:55 -08:00
pack-check.c
pack-objects.c use CALLOC_ARRAY 2021-03-13 16:00:09 -08:00
pack-objects.h
pack-revindex.c Merge branch 'tb/reverse-midx' 2021-04-08 13:23:25 -07:00
pack-revindex.h pack-revindex: read multi-pack reverse indexes 2021-04-01 13:07:37 -07:00
pack-write.c Merge branch 'tb/reverse-midx' 2021-04-08 13:23:25 -07:00
pack.h Merge branch 'tb/reverse-midx' 2021-04-08 13:23:25 -07:00
packfile.c is_promisor_object(): free tree buffer after parsing 2021-04-13 13:16:39 -07:00
packfile.h packfile: introduce 'find_kept_pack_entry()' 2021-02-22 23:30:52 -08:00
pager.c
parse-options-cb.c
parse-options.c parse-options: don't leak alias help messages 2021-03-21 14:39:10 -07:00
parse-options.h parse-options: don't leak alias help messages 2021-03-21 14:39:10 -07:00
patch-delta.c
patch-ids.c use CALLOC_ARRAY 2021-03-13 16:00:09 -08:00
patch-ids.h
path.c
path.h
pathspec.c use CALLOC_ARRAY 2021-03-13 16:00:09 -08:00
pathspec.h
pkt-line.c pkt-line: add options argument to read_packetized_to_strbuf() 2021-03-15 14:32:50 -07:00
pkt-line.h pkt-line: add options argument to read_packetized_to_strbuf() 2021-03-15 14:32:50 -07:00
preload-index.c preload-index: log the number of lstat calls to trace2 2021-02-16 17:14:34 -08:00
pretty.c Merge branch 'rs/pretty-describe' 2021-03-22 14:00:24 -07:00
pretty.h Merge branch 'rs/pretty-describe' 2021-03-22 14:00:24 -07:00
prio-queue.c
prio-queue.h
progress.c use CALLOC_ARRAY 2021-03-13 16:00:09 -08:00
progress.h
promisor-remote.c use CALLOC_ARRAY 2021-03-13 16:00:09 -08:00
promisor-remote.h
prompt.c
prompt.h
protocol.c
protocol.h
prune-packed.c
prune-packed.h
quote.c
quote.h
range-diff.c use CALLOC_ARRAY 2021-03-13 16:00:09 -08:00
range-diff.h Merge branch 'js/range-diff-one-side-only' 2021-02-17 17:21:41 -08:00
reachable.c
reachable.h
read-cache.c Merge branch 'rs/calloc-array' 2021-03-19 15:25:38 -07:00
rebase-interactive.c rebase -i: clarify and fix 'fixup -c' rebase-todo help 2021-02-10 13:58:19 -08:00
rebase-interactive.h
rebase.c
rebase.h
ref-filter.c Merge branch 'rs/xcalloc-takes-nelem-first' 2021-03-19 15:25:39 -07:00
ref-filter.h
reflog-walk.c use CALLOC_ARRAY 2021-03-13 16:00:09 -08:00
reflog-walk.h
refs.c lookup_unknown_object(): take a repository argument 2021-04-13 13:18:46 -07:00
refs.h Merge branch 'tb/ls-refs-optim' 2021-02-05 16:40:45 -08:00
refspec.c
refspec.h
remote-curl.c
remote.c use CALLOC_ARRAY 2021-03-13 16:00:09 -08:00
remote.h Merge branch 'jt/clone-unborn-head' 2021-02-17 17:21:40 -08:00
replace-object.c
replace-object.h
repo-settings.c
repository.c use CALLOC_ARRAY 2021-03-13 16:00:09 -08:00
repository.h
rerere.c
rerere.h
reset.c
reset.h
resolve-undo.c use CALLOC_ARRAY 2021-03-13 16:00:09 -08:00
resolve-undo.h
revision.c revision: avoid parsing with --exclude-promisor-objects 2021-04-13 13:22:37 -07:00
revision.h Merge branch 'zh/format-patch-fractional-reroll-count' 2021-04-02 14:43:14 -07:00
run-command.c use CALLOC_ARRAY 2021-03-13 16:00:09 -08:00
run-command.h
send-pack.c use CALLOC_ARRAY 2021-03-13 16:00:09 -08:00
send-pack.h
sequencer.c Merge branch 'en/sequencer-edit-upon-conflict-fix' 2021-04-08 13:23:26 -07:00
sequencer.h sequencer: fix edit handling for cherry-pick and revert messages 2021-03-31 14:10:50 -07:00
serve.c
serve.h
server-info.c use CALLOC_ARRAY 2021-03-13 16:00:09 -08:00
setup.c
sh-i18n--envsubst.c
sha1dc_git.c
sha1dc_git.h
shallow.c
shallow.h
shell.c
shortlog.h
sideband.c
sideband.h
sigchain.c
sigchain.h
simple-ipc.h simple-ipc: add Unix domain socket implementation 2021-03-22 11:52:54 -07:00
split-index.c use CALLOC_ARRAY 2021-03-13 16:00:09 -08:00
split-index.h
stable-qsort.c
strbuf.c
strbuf.h
streaming.c
streaming.h
string-list.c
string-list.h
strmap.c
strmap.h
strvec.c
strvec.h
sub-process.c
sub-process.h
submodule-config.c
submodule-config.h
submodule.c
submodule.h
symlinks.c checkout: don't follow symlinks when removing entries 2021-03-18 12:58:10 -07:00
tag.c gpg-interface: improve interface for parsing tags 2021-02-10 23:35:42 -08:00
tag.h
tar.h
tempfile.c
tempfile.h
thread-utils.c
thread-utils.h
tmp-objdir.c
tmp-objdir.h
trace.c
trace.h
trace2.c
trace2.h
trailer.c Merge branch 'rs/xcalloc-takes-nelem-first' 2021-03-19 15:25:39 -07:00
trailer.h
transport-helper.c use CALLOC_ARRAY 2021-03-13 16:00:09 -08:00
transport-internal.h
transport.c Merge branch 'll/clone-reject-shallow' 2021-04-08 13:23:25 -07:00
transport.h builtin/clone.c: add --reject-shallow option 2021-04-01 12:58:58 -07:00
tree-diff.c
tree-walk.c
tree-walk.h
tree.c tree.h API: simplify read_tree_recursive() signature 2021-03-20 16:09:26 -07:00
tree.h tree.h API: simplify read_tree_recursive() signature 2021-03-20 16:09:26 -07:00
unicode-width.h
unimplemented.sh
unix-socket.c unix-socket: disallow chdir() when creating unix domain sockets 2021-03-15 14:32:51 -07:00
unix-socket.h unix-socket: disallow chdir() when creating unix domain sockets 2021-03-15 14:32:51 -07:00
unix-stream-server.c unix-stream-server: create unix domain socket under lock 2021-03-15 14:32:51 -07:00
unix-stream-server.h unix-stream-server: create unix domain socket under lock 2021-03-15 14:32:51 -07:00
unpack-trees.c Merge branch 'mt/parallel-checkout-part-1' 2021-04-02 14:43:14 -07:00
unpack-trees.h stash show: teach --include-untracked and --only-untracked 2021-03-05 14:31:26 -08:00
upload-pack.c lookup_unknown_object(): take a repository argument 2021-04-13 13:18:46 -07:00
upload-pack.h
url.c
url.h
urlmatch.c
urlmatch.h
usage.c usage: trace2 BUG() invocations 2021-02-09 14:14:34 -08:00
userdiff.c
userdiff.h
utf8.c
utf8.h
varint.c
varint.h
version.c
version.h
versioncmp.c
walker.c lookup_unknown_object(): take a repository argument 2021-04-13 13:18:46 -07:00
walker.h
wildmatch.c
wildmatch.h
worktree.c use CALLOC_ARRAY 2021-03-13 16:00:09 -08:00
worktree.h
wrap-for-bin.sh
wrapper.c add open_nofollow() helper 2021-02-16 09:41:32 -08:00
write-or-die.c
ws.c
wt-status.c use CALLOC_ARRAY 2021-03-13 16:00:09 -08:00
wt-status.h
xdiff-interface.c
xdiff-interface.h
zlib.c

README.md

Build status

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). 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://lore.kernel.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