- 256 entries of 4-byte first-level fan-out table.
- Table of sorted 20-byte SHA1 records for each object in pack.
- Table of 4-byte CRC32 entries for raw pack object data.
- Table of 4-byte offset entries for objects in the pack if offset is
representable with 31 bits or less, otherwise it is an index in the next
table with top bit set.
- Table of 8-byte offset entries indexed from previous table for offsets
which are 32 bits or more (optional).
- 20-byte SHA1 checksum of sorted object names.
- 20-byte SHA1 checksum of the above.
The object SHA1 table is all contiguous so future pack format that would
contain this table directly won't require big changes to the code. It is
also tighter for slightly better cache locality when looking up entries.
Support for large packs exceeding 31 bits in size won't impose an index
size bloat for packs within that range that don't need a 64-bit offset.
And because newer objects which are likely to be the most frequently used
are located at the beginning of the pack, they won't pay the 64-bit offset
lookup at run time either even if the pack is large.
Right now an index version 2 is created only when the biggest offset in a
pack reaches 31 bits. It might be a good idea to always use index version
2 eventually to benefit from the CRC32 it contains when reusing pack data
while repacking.
[jc: with the "oops" fix to keep track of the last offset correctly]
Signed-off-by: Nicolas Pitre <nico@cam.org> Signed-off-by: Junio C Hamano <junkio@cox.net>
compute a CRC32 for each object as stored in a pack
The most important optimization for performance when repacking is the
ability to reuse data from a previous pack as is and bypass any delta
or even SHA1 computation by simply copying the raw data from one pack
to another directly.
The problem with this is that any data corruption within a copied object
would go unnoticed and the new (repacked) pack would be self-consistent
with its own checksum despite containing a corrupted object. This is a
real issue that already happened at least once in the past.
In some attempt to prevent this, we validate the copied data by inflating
it and making sure no error is signaled by zlib. But this is still not
perfect as a significant portion of a pack content is made of object
headers and references to delta base objects which are not deflated and
therefore not validated when repacking actually making the pack data reuse
still not as safe as it could be.
Of course a full SHA1 validation could be performed, but that implies
full data inflating and delta replaying which is extremely costly, which
cost the data reuse optimization was designed to avoid in the first place.
So the best solution to this is simply to store a CRC32 of the raw pack
data for each object in the pack index. This way any object in a pack can
be validated before being copied as is in another pack, including header
and any other non deflated data.
Why CRC32 instead of a faster checksum like Adler32? Quoting Wikipedia:
Jonathan Stone discovered in 2001 that Adler-32 has a weakness for very
short messages. He wrote "Briefly, the problem is that, for very short
packets, Adler32 is guaranteed to give poor coverage of the available
bits. Don't take my word for it, ask Mark Adler. :-)" The problem is
that sum A does not wrap for short messages. The maximum value of A for
a 128-byte message is 32640, which is below the value 65521 used by the
modulo operation. An extended explanation can be found in RFC 3309,
which mandates the use of CRC32 instead of Adler-32 for SCTP, the
Stream Control Transmission Protocol.
In the context of a GIT pack, we have lots of small objects, especially
deltas, which are likely to be quite small and in a size range for which
Adler32 is dimed not to be sufficient. Another advantage of CRC32 is the
possibility for recovery from certain types of small corruptions like
single bit errors which are the most probable type of corruptions.
OK what this patch does is to compute the CRC32 of each object written to
a pack within pack-objects. It is not written to the index yet and it is
obviously not validated when reusing pack data yet either.
Signed-off-by: Nicolas Pitre <nico@cam.org> Signed-off-by: Junio C Hamano <junkio@cox.net>
Change a few size and offset variables to more appropriate type, then
add overflow tests on those offsets. This prevents any bad data to be
generated/processed if off_t happens to not be large enough to handle
some big packs.
Better be safe than sorry.
Signed-off-by: Nicolas Pitre <nico@cam.org> Signed-off-by: Junio C Hamano <junkio@cox.net>
make overflow test on delta base offset work regardless of variable size
This patch introduces the MSB() macro to obtain the desired number of
most significant bits from a given variable independently of the variable
type.
It is then used to better implement the overflow test on the OBJ_OFS_DELTA
base offset variable with the property of always working correctly
regardless of the type/size of that variable.
Signed-off-by: Nicolas Pitre <nico@cam.org> Signed-off-by: Junio C Hamano <junkio@cox.net>
The coming index format change doesn't allow for the number of objects
to be determined from the size of the index file directly. Instead, Let's
initialize a field in the packed_git structure with the object count when
the index is validated since the count is always known at that point.
While at it let's reorder some struct packed_git fields to avoid padding
due to needed 64-bit alignment for some of them.
Signed-off-by: Nicolas Pitre <nico@cam.org> Signed-off-by: Junio C Hamano <junkio@cox.net>
* jc/merge-subtree:
A new merge stragety 'subtree'.
It is safe to merge this early as this is a feature that user
explicitly needs to ask for and would not trigger otherwise. A
known issue with the current implementation is that the subtree
matching heuristics is very stupid. It could run ls-tree twice
and try to count intersection.
Giving it wider audience would help it to get improved by
motivated volunteers.
* maint:
Add Documentation/cmd-list.made to .gitignore
git-svn: fix log command to avoid infinite loop on long commit messages
git-svn: dcommit/rebase confused by patches with git-svn-id: lines
git-svn: bail out on incorrect command-line options
git-svn: fix log command to avoid infinite loop on long commit messages
This bug has been around since the the conversion to use the
Git.pm library back in October or November. Eventually I'd like
"git rev-list/log" to have the option to not truncate overly
long messages.
Signed-off-by: Eric Wong <normalperson@yhbt.net> Signed-off-by: Junio C Hamano <junkio@cox.net>
git-svn: dcommit/rebase confused by patches with git-svn-id: lines
When patches are merged from another git-svn managed branch,
they will have the git-svn-id: metadata line in them (generated
by git-format-patch).
When doing rebase or dcommit via git-svn, this would cause
git-svn to find the wrong upstream branch. We now verify
that the commit is consistent with the value in the .rev_db
file.
Signed-off-by: Eric Wong <normalperson@yhbt.net> Signed-off-by: Junio C Hamano <junkio@cox.net>
git-svn: bail out on incorrect command-line options
"git svn log" is the only command that needs the pass-through
option in Getopt::Long; otherwise we will bail out and let the
user know something is wrong.
Also, avoid printing out unaccepted mixed-case options (that
are reserved for the command-line) such as --useSvmProps
in the usage() function.
Signed-off-by: Eric Wong <normalperson@yhbt.net> Signed-off-by: Junio C Hamano <junkio@cox.net>
* 'jc/read-tree-df' (early part):
Fix switching to a branch with D/F when current branch has file D.
Fix twoway_merge that passed d/f conflict marker to merged_entry().
Fix read-tree --prefix=dir/.
unpack-trees: get rid of *indpos parameter.
unpack_trees.c: pass unpack_trees_options structure to keep_entry() as well.
add_cache_entry(): removal of file foo does not conflict with foo/bar
This merge strategy largely piggy-backs on git-merge-recursive.
When merging trees A and B, if B corresponds to a subtree of A,
B is first adjusted to match the tree structure of A, instead of
reading the trees at the same level. This adjustment is also
done to the common ancestor tree.
If you are pulling updates from git-gui repository into git.git
repository, the root level of the former corresponds to git-gui/
subdirectory of the latter. The tree object of git-gui's toplevel
is wrapped in a fake tree object, whose sole entry has name 'git-gui'
and records object name of the true tree, before being used by
the 3-way merge code.
If you are merging the other way, only the git-gui/ subtree of
git.git is extracted and merged into git-gui's toplevel.
The detection of corresponding subtree is done by comparing the
pathnames and types in the toplevel of the tree.
git-push to multiple locations does not stop at the first failure
When pushing into multiple repositories with git push, via
multiple URL in .git/remotes/$shorthand or multiple url
variables in [remote "$shorthand"] section, we used to stop upon
the first failure. Continue the operation and report the
failure at the end.
This came up on #git when somebody was getting 'unable to create
./objects/tmp_oXXXX' but sweared he had write permission to that
directory. It turned out that the repository URL was changed
and he was accessing a repository he does not have a write
permission anymore.
I am not sure how much this would have helped somebody who
believed he was accessing location when the permission of that
location was changed while he was looking the other way, though.
But giving more information on the error path would be better,
and the next change would be helped with this as well.
* cc/bisect:
git-bisect: allow bisecting with only one bad commit.
t6030: add a bit more tests to git-bisect
git-bisect: modernization
Documentation: bisect: "start" accepts one bad and many good commits
Bisect: teach "bisect start" to optionally use one bad and many good revs.
* maint:
Documentation: tighten dependency for git.{html,txt}
Makefile: iconv() on Darwin has the old interface
t5300-pack-object.sh: portability issue using /usr/bin/stat
t3200-branch.sh: small language nit
usermanual.txt: some capitalization nits
Make builtin-branch.c handle the git config file
rename_ref(): only print a warning when config-file update fails
Distinguish branches by more than case in tests.
Avoid composing too long "References" header.
cvsimport: Improve formating consistency
cvsimport: Reorder options in documentation for better understanding
cvsimport: Improve usage error reporting
cvsimport: Improve documentation of CVSROOT and CVS module determination
cvsimport: sync usage lines with existing options
Documentation: tighten dependency for git.{html,txt}
Every time _any_ documentation page changed, cmds-*.txt files
were regenerated, which caused git.{html,txt} to be remade. Try
not to update cmds-*.txt files if their new contents match the
old ones.
The libiconv on Darwin uses the old iconv() interface (2nd argument is a
const char **, instead of a char **). Add OLD_ICONV to the Darwin
variable definitions to handle this.
Signed-off-by: Arjen Laarhoven <arjen@yaph.org> Acked-by: Brian Gernhardt <benji@silverinsanity.com> Signed-off-by: Junio C Hamano <junkio@cox.net>
t5300-pack-object.sh: portability issue using /usr/bin/stat
In the test 'compare delta flavors', /usr/bin/stat is used to get file size.
This isn't portable. There already is a dependency on Perl, use its '-s'
operator to get the file size.
Signed-off-by: Arjen Laarhoven <arjen@yaph.org> Signed-off-by: Junio C Hamano <junkio@cox.net>
git-bisect: allow bisecting with only one bad commit.
This allows you to say:
git bisect start
git bisect bad $bad
git bisect next
to start bisection without knowing a good commit. This would
have you try a commit that is half-way since the beginning of
the history, which is rather wasteful if you already know a good
commit, but if you don't (or your history is short enough that
you do not care), there is no reason not to allow this.
This moves the knowledge about .git/config usage out of refs.c and into
builtin-branch.c instead, which allows git-branch to update HEAD to point
at the moved branch before attempting to update the config file. It also
allows git-branch to exit with an error code if updating the config file
should fail.
Signed-off-by: Lars Hjemli <hjemli@gmail.com> Signed-off-by: Junio C Hamano <junkio@cox.net>
rename_ref(): only print a warning when config-file update fails
If git_config_rename_section() fails, rename_ref() used to return 1, which
left HEAD pointing to an absent refs/heads file (since the actual renaming
had already occurred).
Signed-off-by: Lars Hjemli <hjemli@gmail.com> Signed-off-by: Junio C Hamano <junkio@cox.net>
The number of characters in a line MUST be no more than 998 characters,
and SHOULD be no more than 78 characters (RFC2822).
It is much safer to fold the header by ourselves.
Signed-off-by: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org> Signed-off-by: Junio C Hamano <junkio@cox.net>
cvsimport: Reorder options in documentation for better understanding
The current order the options are documented in makes no sense
at all to me. Reorder them so that similar options are grouped
together and also order them somehwhat by importance.
Signed-off-by: Frank Lichtenheld <frank@lichtenheld.de> Signed-off-by: Junio C Hamano <junkio@cox.net>
Sync both the usage lines in the code and the asciidoc
documentation with the real list of options. While
all options seems to be documented in the asciidoc
document, not all of them were listed in the usage line.
Signed-off-by: Frank Lichtenheld <frank@lichtenheld.de> Signed-off-by: Junio C Hamano <junkio@cox.net>
* maint:
Fix lseek(2) calls with args 2 and 3 swapped
Honor -p<n> when applying git diffs
Fix dependency of common-cmds.h
Fix renaming branch without config file
DESTDIR support for git/contrib/emacs
gitweb: Fix bug in "blobdiff" view for split (e.g. file to symlink) patches
Document --left-right option to rev-list.
Revert "builtin-archive: use RUN_SETUP"
rename contrib/hooks/post-receieve-email to contrib/hooks/post-receive-email.
rerere: make sorting really stable.
Fix t4200-rerere for white-space from "wc -l"
Bisect: teach "bisect start" to optionally use one bad and many good revs.
One bad commit is fundamentally needed for bisect to run,
and if we beforehand know more good commits, we can narrow
the bisect space down without doing the whole tree checkout
every time we give good commits.
git bisect start
git bisect bad $bad
git bisect good $good1 $good2...
On the other hand, there may be some confusion between revs
(<bad> and <good>...) and <pathspec>... if -- is not used
and if an invalid rev or a pathspec that looks like a rev is
given.
Signed-off-by: Christian Couder <chriscool@tuxfamily.org> Signed-off-by: Junio C Hamano <junkio@cox.net>
This function was not called "add_file_to_cache()" only because
an ancient program, update-cache, used that name as an internal
function name that does something slightly different. Now that
is gone, we can take over the better name.
The plan is to name all functions that operate on the default
index xxx_cache(). Later patches create a variant of them that
take an explicit parameter xxx_index(), and then turn
xxx_cache() functions into macros that use "the_index".
Rename internal function "add_file_to_cache" in builtin-update-index.c
I'd like to consistently name all index-layer functions that
operate on the default index xxx_cache(), and this application
specific function interferes with the plan.
Propagate cache error internal to refresh_cache() via parameter.
The function refresh_cache() is the only user of cache_errno
that switches its behaviour based on what internal function
refresh_cache_entry() finds; pass the error status back in a
parameter passed down to it, to get rid of the global variable
cache_errno.
Fix bogus error message from merge-recursive error path
This error message should not usually trigger, but the function
make_cache_entry() called by add_cacheinfo() can return early
without calling into refresh_cache_entry() that sets cache_errno.
Also the error message had a wrong function name reported, and
it did not say anything about which path failed either.
Previously, a binary file in the diffstat would show as:
some-binary-file.bin | Bin
The space after the "Bin" was never used. This patch changes binary
lines in the diffstat to be:
some-binary-file.bin | Bin 12345 -> 123456 bytes
The very nice "->" notation was suggested by Johannes Schindelin, and
shows the before and after sizes more clearly than "+" and "-" would.
If a size is 0 it's not shown (although it would probably be better to
treat no-file differently from zero-byte-file).
The user can see what changed in the binary file, and how big the new
file is. This is in keeping with the information in the rest of the
diffstat.
The diffstat_t members "added" and "deleted" were unused when the file
was binary, so this patch loads them with the file sizes in
builtin_diffstat(). These figures are then read in show_stats() when
the file is marked binary.
Signed-off-by: Andy Parkins <andyparkins@gmail.com> Signed-off-by: Junio C Hamano <junkio@cox.net>
If the user is trying to apply a Git generated diff file and they
have specified a -p<n> option, where <n> is not 1, the user probably
has a good reason for doing this. Such as they are me, trying to
apply a patch generated in git.git for the git-gui subdirectory to
the git-gui.git repository, where there is no git-gui subdirectory
present.
Users shouldn't supply -p2 unless they mean it. But if they are
supplying it, they probably have thought about how to make this
patch apply to their working directory, and want to risk whatever
results may come from that.
Signed-off-by: Shawn O. Pearce <spearce@spearce.org> Signed-off-by: Junio C Hamano <junkio@cox.net>
Fix lost-found to show commits only referenced by reflogs
Prior to 1.5.0 the git-lost-found utility was useful to locate
commits that were not referenced by any ref. These were often
amends, or resets, or tips of branches that had been deleted.
Being able to locate a 'lost' commit and recover it by creating a
new branch was a useful feature in those days.
Unfortunately 1.5.0 added the reflogs to the reachability analysis
performed by git-fsck, which means that most commits users would
consider to be lost are still reachable through a reflog. So most
(or all!) commits are reachable, and nothing gets output from
git-lost-found.
Now git-fsck can be told to ignore reflogs during its reachability
analysis, making git-lost-found useful again to locate commits
that are no longer referenced by a ref itself, but may still be
referenced by a reflog.
Signed-off-by: Shawn O. Pearce <spearce@spearce.org> Signed-off-by: Junio C Hamano <junkio@cox.net>
clean up and optimize nth_packed_object_sha1() usage
Let's avoid the open coded pack index reference in pack-object and use
nth_packed_object_sha1() instead. This will help encapsulating index
format differences in one place.
And while at it there is no reason to copy SHA1's over and over while a
direct pointer to it in the index will do just fine.
Signed-off-by: Nicolas Pitre <nico@cam.org> Acked-by: Shawn O. Pearce <spearce@spearce.org> Signed-off-by: Junio C Hamano <junkio@cox.net>
Make git_config_rename_section return success if no config file
exists. Otherwise, renaming a branch would abort, leaving the
repository in an inconsistent state.
[jc: test]
Signed-off-by: Geert Bosch <bosch@gnat.com> Signed-off-by: Junio C Hamano <junkio@cox.net>
gitweb: Fix bug in "blobdiff" view for split (e.g. file to symlink) patches
git_patchset_body needs patch generated with --full-index option to
detect split patches, meaning two patches which corresponds to single
difftree (raw diff) entry. An example of such situation is changing
type (mode) of a file, e.g. from plain file to symbolic link.
Add, in git_blobdiff, --full-index option to patch generating git diff
invocation, for the 'html' format output ("blobdiff" view).
"blobdiff_plain" still uses shortened sha1 in the extended git diff
header "index <hash>..<hash>[ <mode>]" line.
Noticed-by: Martin Koegler <mkoegler@auto.tuwien.ac.at> Signed-off-by: Jakub Narebski <jnareb@gmail.com> Signed-off-by: Junio C Hamano <junkio@cox.net>
Commit 64edf4b2 cleaned up the initialization of git-archive,
at the cost of 'git-archive --list' now requiring a git repo.
This patch reverts the cleanup and documents the requirement
for this particular dirtyness in a test.
Signed-off-by: Rene Scharfe <rene.scharfe@lsrfire.ath.cx> Signed-off-by: Junio C Hamano <junkio@cox.net>
The earlier code does not swap hunks when the beginning of the
first side is identical to the whole of the second side. In
such a case, the first one should sort later.
On OS X, wc outputs 6 spaces before the number of lines, so the test
expecting the string "10" failed. Do not quote $cmd to strip away
the problematic whitespace as other tests do.
Also fix the grammar of the test name while making changes to it.
There's only one preimage, so it's "has", not "have".
git-svn: bail out on incorrect command-line options
"git svn log" is the only command that needs the pass-through
option in Getopt::Long; otherwise we will bail out and let the
user know something is wrong.
Also, avoid printing out unaccepted mixed-case options (that
are reserved for the command-line) such as --useSvmProps
in the usage() function.
Signed-off-by: Eric Wong <normalperson@yhbt.net> Signed-off-by: Junio C Hamano <junkio@cox.net>
Fix switching to a branch with D/F when current branch has file D.
This loosens the over-eager verify_absent() check that gets
upset to find directory D in the current working tree when
switching to a branch that has a file there. The check needs to
make sure that we do not lose precious working tree files as a
result of removing directory D and replacing it with the file
from the other branch, which is a tad expensive but this is a
less common case.
Fix twoway_merge that passed d/f conflict marker to merged_entry().
When switching from one tree to another, we should not send a
marker that says "this file does not exist in the new tree -- I
am a placeholder to tell you that, and not a real blob" down to
merged_entry() as the result of the merge.
This variable keeps track of which entry in the original index
the traversal is looking at, and belongs to the unpack_trees_options
structure along with other traversal status information.
unpack_trees.c: pass unpack_trees_options structure to keep_entry() as well.
Other decision functions, deleted_entry() and merged_entry() take one as
their parameter, and this function should. I'll be introducing a separate
index to build the result in, and am planning to pass it as the part of the
structure.
* jc/bisect:
make the previous optimization work also on path-limited rev-list --bisect
rev-list --bisect: Fix "halfway" optimization.
t6004: add a bit more path optimization test.
git-rev-list --bisect: optimization
git-rev-list: add --bisect-vars option.
t6002: minor spelling fix.
* fl/doc:
Documentation: unbreak user-manual.
Documentation: Add version information to man pages
Documentation: Replace @@GIT_VERSION@@ in documentation
* post1.5.1/p4:
Added correct Python path to the RPM specfile.
Remove unused WITH_OWN_SUBPROCESS_PY from RPM spec
Added git-p4 package to the list of git RPMs.
Add the WITH_P4IMPORT knob to the Makefile.
This corrects the interface mistake of the previous one, and
gives a command line parameter to the only plumbing command that
currently needs it: "git-read-tree".
We can add the calls to set_alternate_index_output() to other
plumbing commands that update the index if/when needed.
_GIT_INDEX_OUTPUT: allow plumbing to output to an alternative index file.
When defined, this allows plumbing commands that update the
index (add, apply, checkout-index, merge-recursive, mv,
read-tree, rm, update-index, and write-tree) to write their
resulting index to an alternative index file while holding a
lock to the original index file. With this, git-commit that
jumps the index does not have to make an extra copy of the index
file, and more importantly, it can do the update while holding
the lock on the index.
However, I think the interface to let an environment variable
specify the output is a mistake, as shown in the documentation.
If a curious user has the environment variable set to something
other than the file GIT_INDEX_FILE points at, almost everything
will break. This should instead be a command line parameter to
tell these plumbing commands to write the result in the named
file, to prevent stupid mistakes.
Not that this release really matters, as we will be doing
1.5.1 tomorrow. This commit is to tie the loose ends and
merge all of "maint" branch into "master" in preparation.
Rewrite Tcl/Tk interpreter path for the GUI tools.
--with-tcltk=/path/to/wish sets the TCLTK_PATH variable that is
used to substitute the location of the wish interpreter in the
Tcl/Tk programs.
New tracking file, GIT-GUI-VARS, was introduced: it tracks the
location of the Tcl/Tk interpreter and activates the GUI tools
rebuild if the interpreter path was changed. The separate tracker
is better than the GIT-CFLAGS: there is no need to rebuild the whole
git if the interpreter path was changed.