1
0
mirror of https://github.com/git/git.git synced 2024-10-22 12:28:32 +02:00
Git Source Code Mirror. Please follow Documentation/SubmittingPatches procedure for any of your improvements.
Go to file
Jeff King 1a6d8b9148 do not discard revindex when re-preparing packfiles
When an object lookup fails, we re-read the objects/pack
directory to pick up any new packfiles that may have been
created since our last read. We also discard any pack
revindex structs we've allocated.

The discarding is a problem for the pack-bitmap code, which keeps
a pointer to the revindex for the bitmapped pack. After the
discard, the pointer is invalid, and we may read free()d
memory.

Other revindex users do not keep a bare pointer to the
revindex; instead, they always access it through
revindex_for_pack(), which lazily builds the revindex. So
one solution is to teach the pack-bitmap code a similar
trick. It would be slightly less efficient, but probably not
all that noticeable.

However, it turns out this discarding is not actually
necessary. When we call reprepare_packed_git, we do not
throw away our old pack list. We keep the existing entries,
and only add in new ones. So there is no safety problem; we
will still have the pack struct that matches each revindex.
The packfile itself may go away, of course, but we are
already prepared to handle that, and it may happen outside
of reprepare_packed_git anyway.

Throwing away the revindex may save some RAM if the pack
never gets reused (about 12 bytes per object). But it also
wastes some CPU time (to regenerate the index) if the pack
does get reused. It's hard to say which is more valuable,
but in either case, it happens very rarely (only when we
race with a simultaneous repack). Just leaving the revindex
in place is simple and safe both for current and future
code.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2014-01-16 14:33:46 -08:00
block-sha1
builtin
compat compat: add endianness helpers 2013-11-18 10:57:42 -08:00
contrib
Documentation
ewah
git-gui
gitk-git
gitweb
mergetools
perl
po
ppc
t
templates
vcs-svn
xdiff
.gitattributes
.gitignore
.mailmap
abspath.c
aclocal.m4
advice.c
advice.h
alias.c
alloc.c
archive-tar.c
archive-zip.c
archive.c
archive.h
argv-array.c
argv-array.h
attr.c
attr.h
base85.c
bisect.c
bisect.h
blob.c
blob.h
branch.c
branch.h
builtin.h
bulk-checkin.c
bulk-checkin.h
bundle.c
bundle.h
cache-tree.c
cache-tree.h
cache.h
check_bindir
check-builtins.sh
check-racy.c
color.c
color.h
column.c
column.h
combine-diff.c
command-list.txt
commit-slab.h
commit.c
commit.h
config.c
config.mak.in
config.mak.uname
configure.ac
connect.c
connect.h
connected.c
connected.h
convert.c
convert.h
copy.c
COPYING
credential-cache--daemon.c
credential-cache.c
credential-store.c
credential.c
credential.h
csum-file.c
csum-file.h
ctype.c
daemon.c
date.c
decorate.c
decorate.h
delta.h
diff-delta.c
diff-lib.c
diff-no-index.c
diff.c
diff.h
diffcore-break.c
diffcore-delta.c
diffcore-order.c
diffcore-pickaxe.c
diffcore-rename.c
diffcore.h
dir.c
dir.h
editor.c
entry.c
environment.c
exec_cmd.c
exec_cmd.h
fast-import.c
fetch-pack.c
fetch-pack.h
fmt-merge-msg.h
fsck.c
fsck.h
generate-cmdlist.sh
gettext.c
gettext.h
git-add--interactive.perl
git-am.sh
git-archimport.perl
git-bisect.sh
git-compat-util.h
git-cvsexportcommit.perl
git-cvsimport.perl
git-cvsserver.perl
git-difftool--helper.sh
git-difftool.perl
git-filter-branch.sh
git-instaweb.sh
git-lost-found.sh
git-merge-octopus.sh
git-merge-one-file.sh
git-merge-resolve.sh
git-mergetool--lib.sh
git-mergetool.sh
git-p4.py
git-parse-remote.sh
git-pull.sh
git-quiltimport.sh
git-rebase--am.sh
git-rebase--interactive.sh
git-rebase--merge.sh
git-rebase.sh
git-relink.perl
git-remote-testgit.sh
git-request-pull.sh
git-send-email.perl
git-sh-i18n.sh
git-sh-setup.sh
git-stash.sh
git-submodule.sh
git-svn.perl
GIT-VERSION-GEN
git-web--browse.sh
git.c
git.rc
git.spec.in
gpg-interface.c
gpg-interface.h
graph.c
graph.h
grep.c
grep.h
hash.c
hash.h
help.c
help.h
hex.c
http-backend.c
http-fetch.c
http-push.c
http-walker.c
http.c
http.h
ident.c
imap-send.c
INSTALL
khash.h
kwset.c
kwset.h
levenshtein.c
levenshtein.h
LGPL-2.1
line-log.c
line-log.h
line-range.c
line-range.h
list-objects.c
list-objects.h
ll-merge.c
ll-merge.h
lockfile.c
log-tree.c
log-tree.h
mailmap.c
mailmap.h
Makefile
match-trees.c
merge-blobs.c
merge-blobs.h
merge-recursive.c
merge-recursive.h
merge.c
mergesort.c
mergesort.h
name-hash.c
notes-cache.c
notes-cache.h
notes-merge.c
notes-merge.h
notes-utils.c
notes-utils.h
notes.c
notes.h
object.c
object.h
pack-bitmap-write.c
pack-bitmap.c
pack-bitmap.h
pack-check.c
pack-objects.c
pack-objects.h
pack-revindex.c
pack-revindex.h
pack-write.c
pack.h
pager.c
parse-options-cb.c
parse-options.c
parse-options.h
patch-delta.c
patch-ids.c
patch-ids.h
path.c
pathspec.c
pathspec.h
pkt-line.c
pkt-line.h
preload-index.c
pretty.c
prio-queue.c
prio-queue.h
progress.c
progress.h
prompt.c
prompt.h
quote.c
quote.h
reachable.c
reachable.h
read-cache.c
README
reflog-walk.c
reflog-walk.h
refs.c
refs.h
RelNotes
remote-curl.c
remote-testsvn.c
remote.c
remote.h
replace_object.c
rerere.c
rerere.h
resolve-undo.c
resolve-undo.h
revision.c
revision.h
run-command.c
run-command.h
send-pack.c
send-pack.h
sequencer.c
sequencer.h
server-info.c
setup.c
sh-i18n--envsubst.c
sha1_file.c
sha1_name.c
sha1-array.c
sha1-array.h
sha1-lookup.c
sha1-lookup.h
shallow.c
shell.c
shortlog.h
show-index.c
sideband.c
sideband.h
sigchain.c
sigchain.h
strbuf.c
strbuf.h
streaming.c
streaming.h
string-list.c
string-list.h
submodule.c
submodule.h
symlinks.c
tag.c
tag.h
tar.h
test-chmtime.c
test-ctype.c
test-date.c
test-delta.c
test-dump-cache-tree.c
test-genrandom.c
test-index-version.c
test-line-buffer.c
test-match-trees.c
test-mergesort.c
test-mktemp.c
test-parse-options.c
test-path-utils.c
test-prio-queue.c
test-read-cache.c
test-regex.c
test-revision-walking.c
test-run-command.c
test-scrap-cache-tree.c
test-sha1.c
test-sha1.sh
test-sigchain.c
test-string-list.c
test-subprocess.c
test-svn-fe.c
test-urlmatch-normalization.c
test-wildmatch.c
thread-utils.c
thread-utils.h
trace.c
transport-helper.c
transport.c
transport.h
tree-diff.c
tree-walk.c
tree-walk.h
tree.c
tree.h
unimplemented.sh
unix-socket.c
unix-socket.h
unpack-trees.c
unpack-trees.h
upload-pack.c
url.c
url.h
urlmatch.c
urlmatch.h
usage.c
userdiff.c
userdiff.h
utf8.c
utf8.h
varint.c
varint.h
version.c
version.h
walker.c
walker.h
wildmatch.c
wildmatch.h
wrap-for-bin.sh
wrapper.c
write_or_die.c
ws.c
wt-status.c
wt-status.h
xdiff-interface.c
xdiff-interface.h
zlib.c

////////////////////////////////////////////////////////////////

	Git - the stupid content tracker

////////////////////////////////////////////////////////////////

"git" can mean anything, 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

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.

See Documentation/gittutorial.txt to get started, then see
Documentation/everyday.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).

Many Git online resources are accessible from http://git-scm.com/
including full documentation and Git related tools.

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 http://news.gmane.org/gmane.comp.version-control.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.