When copying from an existing pack and when copying from a loose
object with new style header, the code makes sure that the piece
we are going to copy out inflates well and inflate() consumes
the data in full while doing so.
The check to see if the xdelta really apply is quite expensive
as you described, because you would need to have the image of
the base object which can be represented as a delta against
something else.
Signed-off-by: Junio C Hamano <junkio@cox.net>
Like xmalloc and xrealloc xstrdup dies with a useful message if
the native strdup() implementation returns NULL rather than a
valid pointer.
I just tried to use xstrdup in new code and found it to be missing.
However I expected it to be present as xmalloc and xrealloc are
already commonly used throughout the code.
[jc: removed the part that deals with last_XXX, which I am
finding more and more dubious these days.]
Signed-off-by: Shawn O. Pearce <spearce@spearce.org>
Signed-off-by: Junio C Hamano <junkio@cox.net>
Also while we are at it, remove redundant typename[] array from
unpack_sha1_header. The only reason it is different from the
type_names[] array in object.c module is that this code cares
about the subset of object types that are valid in a loose
object, so prepare a separate array of boolean that tells us
which types are valid, and share the name translation with the
others.
Signed-off-by: Junio C Hamano <junkio@cox.net>
Change places that use realloc, without a proper error path, to instead use
xrealloc. Drop an erroneous error path in the daemon code that used errno
in the die message in favour of the simpler xrealloc.
Signed-off-by: Jonas Fonseca <fonseca@diku.dk>
Signed-off-by: Junio C Hamano <junkio@cox.net>
Change unpack_entry_gently and its helper functions to use offsets
rather than addresses and left counts to supply pack position
information. In most cases this makes the code easier to follow,
and it reduces the number of local variables in a few functions.
It also better prepares this code for mapping partial segments of
packs and altering what regions of a pack are mapped while unpacking
an entry.
Signed-off-by: Shawn O. Pearce <spearce@spearce.org>
Signed-off-by: Junio C Hamano <junkio@cox.net>
If we're always incrementing both the offset and the pointer we
aren't gaining anything by keeping both. Instead just use the
offset since that's what we were given and what we are expected
to return. Also using offset is likely to make it easier to remap
the pack in the future should partial mapping of very large packs
get implemented.
Signed-off-by: Shawn O. Pearce <spearce@spearce.org>
Signed-off-by: Junio C Hamano <junkio@cox.net>
[PATCH 3/5] Cleanup unpack_entry_gently and friends to use type_name array.
This change allows combining all of the non-delta entries into a
single case, as well as to remove an unnecessary local variable
in unpack_entry_gently.
Signed-off-by: Shawn O. Pearce <spearce@spearce.org>
Signed-off-by: Junio C Hamano <junkio@cox.net>
[PATCH 2/5] Reuse compression code in unpack_compressed_entry.
This cleans up the code by reusing a perfectly good decompression
implementation at the expense of 1 extra byte of memory allocated in
temporary memory while the delta is being decompressed and applied
to the base.
Signed-off-by: Shawn O. Pearce <spearce@spearce.org>
Signed-off-by: Junio C Hamano <junkio@cox.net>
This function was moved above unpack_delta_entry so we can call it
from within unpack_delta_entry without a forward declaration.
This change looks worse than it is. Its really just a relocation
of unpack_non_delta_entry to earlier in the file and renaming the
function to unpack_compressed_entry. No other changes were made.
Signed-off-by: Shawn O. Pearce <spearce@spearce.org>
Signed-off-by: Junio C Hamano <junkio@cox.net>
This abstracts away the size of the hash values when copying them
from memory location to memory location, much as the introduction
of hashcmp abstracted away hash value comparsion.
A few call sites were using char* rather than unsigned char* so
I added the cast rather than open hashcpy to be void*. This is a
reasonable tradeoff as most call sites already use unsigned char*
and the existing hashcmp is also declared to be unsigned char*.
[jc: Splitted the patch to "master" part, to be followed by a
patch for merge-recursive.c which is not in "master" yet.
Fixed the cast in the latter hunk to combine-diff.c which was
wrong in the original.
Also converted ones left-over in combine-diff.c, diff-lib.c and
upload-pack.c ]
Signed-off-by: Shawn O. Pearce <spearce@spearce.org>
Signed-off-by: Junio C Hamano <junkio@cox.net>
This declaration probably used to be necessary but the code has
been refactored since to use unpack_entry_gently instead.
Signed-off-by: Shawn O. Pearce <spearce@spearce.org>
Signed-off-by: Junio C Hamano <junkio@cox.net>
If the pack format were to ever change or be extended in the future
there is no assurance that just because the pack file lives in
objects/pack and doesn't end in .idx that we can read and decompress
its contents properly.
If we encounter what we think is a pack file and it isn't or we don't
recognize its version then die and suggest to the user that they
upgrade to a newer version of GIT which can handle that pack file.
Signed-off-by: Shawn O. Pearce <spearce@spearce.org>
Signed-off-by: Junio C Hamano <junkio@cox.net>
Introduces global inline:
hashcmp(const unsigned char *sha1, const unsigned char *sha2)
Uses memcmp for comparison and returns the result based on the length of
the hash name (a future runtime decision).
Acked-by: Alex Riesen <raa.lkml@gmail.com>
Signed-off-by: David Rientjes <rientjes@google.com>
Signed-off-by: Junio C Hamano <junkio@cox.net>
[jc: I needed to hand merge the changes to the updated codebase,
so the result needs to be checked.]
Signed-off-by: David Rientjes <rientjes@google.com>
Signed-off-by: Junio C Hamano <junkio@cox.net>
As Fredrik points out the current interface of has_extension() is
potentially confusing. Its parameters include both a nul-terminated
string and a length-limited string.
This patch drops the length argument, requiring two nul-terminated
strings; all callsites are updated. I checked that all of them indeed
provide nul-terminated strings. Filenames need to be nul-terminated
anyway if they are to be passed to open() etc. The performance penalty
of the additional strlen() is negligible compared to the system calls
which inevitably surround has_extension() calls.
Additionally, change has_extension() to use size_t inside instead of
int, as that is the exact type strlen() returns and memcmp() expects.
Signed-off-by: Rene Scharfe <rene.scharfe@lsrfire.ath.cx>
Signed-off-by: Junio C Hamano <junkio@cox.net>
The little helper has_extension() documents through its name what we are
trying to do and makes sure we don't forget the underrun check.
Signed-off-by: Rene Scharfe <rene.scharfe@lsrfire.ath.cx>
Signed-off-by: Junio C Hamano <junkio@cox.net>
This exposes map_sha1_file() interface to mmap a loose object file,
and legacy_loose_object() function, split from unpack_sha1_header().
They will be used in the next patch to reuse the deflated data from
new-style loose object files when generating packs.
Signed-off-by: Junio C Hamano <junkio@cox.net>
The pack-file format is slightly different from the traditional git
object format, in that it has a much denser binary header encoding.
The traditional format uses an ASCII string with type and length
information, which is somewhat wasteful.
A new object format starts with uncompressed binary header
followed by compressed payload -- this will allow us later to
copy the payload straight to packfiles.
Obviously they cannot be read by older versions of git, so for
now new object files are created with the traditional format.
core.legacyheaders configuration item, when set to false makes
the code write in new format for people to experiment with.
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Signed-off-by: Junio C Hamano <junkio@cox.net>
Linus Torvalds <torvalds@osdl.org> wrote:
It's entirely possible that we should just make that whole
if (ret == ENOENT)
go away. Yes, it's the right error code if a subdirectory is missing, and
yes, POSIX requires it, and yes, WXP is probably just a horrible piece of
sh*t, but on the other hand, I don't think git really has any serious
reason to even care.
Nobody else uses them, and I'm going to start changing them.
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Signed-off-by: Junio C Hamano <junkio@cox.net>
This doesn't make the code uglier or harder to read, yet it makes the
code more portable. This also simplifies checking for other potential
incompatibilities. "gcc -std=c89 -pedantic" can flag many incompatible
constructs as warnings, but C99 comments will cause it to emit an error.
Signed-off-by: Pavel Roskin <proski@gnu.org>
Signed-off-by: Junio C Hamano <junkio@cox.net>
The only visible change is that git-blame doesn't understand
"--compability" anymore, but it does accept "--compatibility" instead,
which is already documented.
Signed-off-by: Pavel Roskin <proski@gnu.org>
Signed-off-by: Junio C Hamano <junkio@cox.net>
With the change in default, "git add ." on kernel dir is about
twice as fast as before, with only minimal (0.5%) change in
object size. The speed difference is even more noticeable
when committing large files, which is now up to 8 times faster.
The configurability is through setting core.compression = [-1..9]
which maps to the zlib constants; -1 is the default, 0 is no
compression, and 1..9 are various speed/size tradeoffs, 9
being slowest.
Signed-off-by: Joachim B Haga (cjhaga@fys.uio.no)
Acked-by: Linus Torvalds <torvalds@osdl.org>
Signed-off-by: Junio C Hamano <junkio@cox.net>
ANSI C99 doesn't allow void-pointer arithmetic. This patch fixes this in
various ways. Usually the strategy that required the least changes was used.
Signed-off-by: Florian Forster <octo@verplant.org>
Signed-off-by: Junio C Hamano <junkio@cox.net>
There were a few calls to adjust_shared_perm() that were
missing:
- init-db creates refs, refs/heads, and refs/tags before
reading from templates that could specify sharedrepository in
the config file;
- updating config file created it under user's umask without
adjusting;
- updating refs created it under user's umask without
adjusting;
- switching branches created .git/HEAD under user's umask
without adjusting.
This moves adjust_shared_perm() from sha1_file.c to path.c,
since a few SIMPLE_PROGRAM need to call repository configuration
functions which in turn need to call adjust_shared_perm().
sha1_file.c needs to link with SHA1 computation library which
is usually not linked to SIMPLE_PROGRAM.
Signed-off-by: Junio C Hamano <junkio@cox.net>
When adding packs, skip the pack if we already have it in the packed_git
list. This might happen if we are re-preparing our packs because of a
missing object.
Signed-off-by: Junio C Hamano <junkio@cox.net>
This patch causes read_sha1_file and sha1_object_info to re-examine the
list of packs if an object cannot be found. It works by re-running
prepare_packed_git() after an object fails to be found.
It does not attempt to clean up the old pack list. Old packs which are in
use can continue to be used (until unused by lru selection). New packs
are placed at the front of the list and will thus be examined before old
packs.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <junkio@cox.net>
This cleans up and future-proofs the sha1 file writing in sha1_file.c.
In particular, instead of doing a simple "write()" call and just verifying
that it succeeds (or - as in one place - just assuming it does), it uses
"write_buffer()" to write data to the file descriptor while correctly
checking for partial writes, EINTR etc.
It also splits up write_sha1_to_fd() to be a lot more readable: if we need
to re-create the compressed object, we do so in a separate helper
function, making the logic a whole lot more modular and obvious.
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Signed-off-by: Junio C Hamano <junkio@cox.net>
* fix:
Fix pack-index issue on 64-bit platforms a bit more portably.
Install git-send-email by default
Fix compilation on newer NetBSD systems
git config syntax updates
Another config file parsing fix.
checkout: use --aggressive when running a 3-way merge (-m).
Apparently <stdint.h> is not enough for uint32_t on OpenBSD; use
"unsigned int" -- hopefully that would stay 32-bit on every
platform we care about, at least until we update the pack-index
file format.
Our sha1 routines optimized for architectures use uint32_t and
expects '#include <stdint.h>' to be enough, so OpenBSD on arm or
ppc might have similar issues down the road, I dunno.
Signed-off-by: Junio C Hamano <junkio@cox.net>
The offset of an object in the pack is recorded as a 4-byte integer
in the index file. When reading the offset from the mmap'ed index
in prepare_pack_revindex(), the address is dereferenced as a long*.
This works fine as long as the long type is four bytes wide. On
NetBSD/sparc64, however, a long is 8 bytes wide and so dereferencing
the offset produces garbage.
[jc: taking suggestion by Linus to use uint32_t]
Signed-off-by: Dennis Stosberg <dennis@stosberg.net>
Signed-off-by: Junio C Hamano <junkio@cox.net>
When adding an alternate object store then add entries from its
info/alternates files, too.
Relative entries are only allowed in the current repository.
Loops and duplicate alternates through multiple repositories are ignored.
Just to be sure that nothing breaks it is not allow to build deep
nesting levels using info/alternates.
Signed-off-by: Martin Waitz <tali@admingilde.org>
Signed-off-by: Junio C Hamano <junkio@cox.net>
Somebody on the #git channel complained that the sha1_to_hex() thing uses
a static buffer which caused an error message to show the same hex output
twice instead of showing two different ones.
That's pretty easily rectified by making it uses a simple LRU of a few
buffers, which also allows some other users (that were aware of the buffer
re-use) to be written in a more straightforward manner.
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Signed-off-by: Junio C Hamano <junkio@cox.net>
Serge E. Hallyn noticed that we compute how many input bytes are
still left, but did not use it for sanity checking.
Signed-off-by: Junio C Hamano <junkio@cox.net>
This replaces occurences of "blob", "commit", "tag", and "tree",
where they're really used as type specifiers, which we already
have defined global constants for.
Signed-off-by: Peter Eriksen <s022018@student.dtu.dk>
Signed-off-by: Junio C Hamano <junkio@cox.net>
Currently we unpack the delta data from the pack and then unpack
the base object to apply that delta data to it. When getting an
object that is deeply deltified, we can reduce memory footprint
by unpacking the base object first and then unpacking the delta
data, because we will need to keep at most one delta data in
memory that way.
Signed-off-by: Junio C Hamano <junkio@cox.net>
When generating a new pack, notice if we have already needed
objects in existing packs. If an object is stored deltified,
and its base object is also what we are going to pack, then
reuse the existing deltified representation unconditionally,
bypassing all the expensive find_deltas() and try_deltas()
calls.
Also, notice if what we are going to write out exactly match
what is already in an existing pack (either deltified or just
compressed). In such a case, we can just copy it instead of
going through the usual uncompressing & recompressing cycle.
Without this patch, in linux-2.6 repository with about 1500
loose objects and a single mega pack:
$ git-rev-list --objects v2.6.16-rc3 >RL
$ wc -l RL
184141 RL
$ time git-pack-objects p <RL
Generating pack...
Done counting 184141 objects.
Packing 184141 objects....................
a1fc7b3e537fcb9b3c46b7505df859f0a11e79d2
real 12m4.323s
user 11m2.560s
sys 0m55.950s
With this patch, the same input:
$ time ../git.junio/git-pack-objects q <RL
Generating pack...
Done counting 184141 objects.
Packing 184141 objects.....................
a1fc7b3e537fcb9b3c46b7505df859f0a11e79d2
Total 184141, written 184141, reused 182441
real 1m2.608s
user 0m55.090s
sys 0m1.830s
Signed-off-by: Junio C Hamano <junkio@cox.net>
The real problem triggered an earlier fix was that an alternate
entry was pointing at a removed directory. Complaining on
object/pack directory that cannot be opendir-ed produces noise
in an ancient repository that does not have object/pack
directory and has never been packed.
Detect the real user error and report it. Also if opendir
failed for other reasons (e.g. no read permissions), report that
as well.
Spotted by Andrew Vasquez <andrew.vasquez@qlogic.com>.
Signed-off-by: Junio C Hamano <junkio@cox.net>
* jc/pack-reuse:
pack-objects: avoid delta chains that are too long.
git-repack: allow passing a couple of flags to pack-objects.
pack-objects: finishing touches.
pack-objects: reuse data from existing packs.
When generating a new pack, notice if we have already needed
objects in existing packs. If an object is stored deltified,
and its base object is also what we are going to pack, then
reuse the existing deltified representation unconditionally,
bypassing all the expensive find_deltas() and try_deltas()
calls.
Also, notice if what we are going to write out exactly match
what is already in an existing pack (either deltified or just
compressed). In such a case, we can just copy it instead of
going through the usual uncompressing & recompressing cycle.
Without this patch, in linux-2.6 repository with about 1500
loose objects and a single mega pack:
$ git-rev-list --objects v2.6.16-rc3 >RL
$ wc -l RL
184141 RL
$ time git-pack-objects p <RL
Generating pack...
Done counting 184141 objects.
Packing 184141 objects....................
a1fc7b3e537fcb9b3c46b7505df859f0a11e79d2
real 12m4.323s
user 11m2.560s
sys 0m55.950s
With this patch, the same input:
$ time ../git.junio/git-pack-objects q <RL
Generating pack...
Done counting 184141 objects.
Packing 184141 objects.....................
a1fc7b3e537fcb9b3c46b7505df859f0a11e79d2
Total 184141, written 184141, reused 182441
real 1m2.608s
user 0m55.090s
sys 0m1.830s
Signed-off-by: Junio C Hamano <junkio@cox.net>
Use stat() to explicitly check for existence rather than
relying on the non-portable EEXIST error in sha1_file.c's
safe_create_leading_directories(). There certainly are
optimizations possible, but then the code becomes almost
the same as that in coreutil's lib/mkdir-p.c.
Other uses of EEXIST seem ok. Tested on Solaris 8, AIX 5.2L,
and a few Linux versions. AIX has some unrelated (I think)
failures right now; I haven't tried many recent gits there.
Anyone have an old Ultrix box to break everything? ;)
Also remove extraneous #includes. Everything's already in
git-compat-util.h, included through cache.h.
Signed-off-by: Jason Riedy <ejr@cs.berkeley.edu>
Signed-off-by: Junio C Hamano <junkio@cox.net>
This reverts c5ced64578 commit.
It turns out that doing this check every time we map the idx file
is quite expensive. A corrupt idx file is caught by git-fsck-objects,
so this check is not strictly necessary.
In one unscientific test, 0.99.9m spent 10 seconds usertime for
the same task 1.1.3 takes 37 seconds usertime. Reverting this gives
us the performance of 0.99.9 back.
If the config variable 'core.sharedrepository' is set, the directories
$GIT_DIR/objects/
$GIT_DIR/objects/??
$GIT_DIR/objects/pack
$GIT_DIR/refs
$GIT_DIR/refs/heads
$GIT_DIR/refs/heads/tags
are set group writable (and g+s, since the git group may be not the primary
group of all users).
Since all files are written as lock files first, and then moved to
their destination, they do not have to be group writable. Indeed, if
this leads to problems you found a bug.
Note that -- as in my first attempt -- the config variable is set in the
function which checks the repository format. If this were done in
git_default_config instead, a lot of programs would need to be modified
to call git_config(git_default_config) first.
[jc: git variables should be in environment.c unless there is a
compelling reason to do otherwise.]
Signed-off-by: Johannes Schindelin <Johannes.Schindelin@gmx.de>
Signed-off-by: Junio C Hamano <junkio@cox.net>
Although pack-check.c had routine to verify the checksum for the
pack index file itself, the core did not check it before using
it.
This is stolen from the patch to tighten packname requirements.
Signed-off-by: Junio C Hamano <junkio@cox.net>
(cherry picked from 797bd6f490 commit)
Although pack-check.c had routine to verify the checksum for the
pack index file itself, the core did not check it before using
it.
This is stolen from the patch to tighten packname requirements.
Signed-off-by: Junio C Hamano <junkio@cox.net>
sha1_to_hex() returns a pointer to a static buffer. Some of its users
modify that buffer by appending a newline character. Other users rely
on the fact that you can call
printf("%s", sha1_to_hex(sha1));
Just to be on the safe side, terminate the SHA1 in sha1_to_hex().
Signed-off-by: Johannes Schindelin <Johannes.Schindelin@gmx.de>
Signed-off-by: Junio C Hamano <junkio@cox.net>
fprintf and die sometimes have missing/excessive "\n" in their arguments,
correct the strings where I think it would be appropriate.
Signed-off-by: Alex Riesen <raa.lkml@gmail.com>
Signed-off-by: Junio C Hamano <junkio@cox.net>
add_packed_git() tries to get the pack SHA1 by parsing its name. It may
access uninitialized memory for packs with short names.
Signed-off-by: Pavel Roskin <proski@gnu.org>
Signed-off-by: Junio C Hamano <junkio@cox.net>
In order to support getting data into git with scripts, this adds a
--stdin option to git-hash-object, which will make it read from stdin.
Signed-off-by: Daniel Barkalow <barkalow@iabervon.org>
Signed-off-by: Junio C Hamano <junkio@cox.net>
We somehow ended up registering packs in alternate object
directories as "dir/object//pack/pack-*", which confusd the
update-server-info code very badly. Also we did not attempt to
detect a mistake of listing the object directory itself as one
of the alternates. This does not lead to incorrect behaviour,
but is simply wasteful, so try to do so when we are trivially
able to.
Signed-off-by: Junio C Hamano <junkio@cox.net>
This patch adds the program git-pack-intersect. It is
used to find redundant packs in git repositories.
Signed-off-by: Lukas Sandström <lukass@etek.chalmers.se>
Signed-off-by: Junio C Hamano <junkio@cox.net>
This fixes a problem in safe_create_leading_directories() when the
argument starts with a '/' (i.e. the path is absolute).
Signed-off-by: Johannes Schindelin <Johannes.Schindelin@gmx.de>
Signed-off-by: Junio C Hamano <junkio@cox.net>
Recent FAT workaround caused compilation trouble on OpenBSD;
different platforms use different error codes when we try to
hardlink the temporary file to its final location. Existing
Coda hack also checks its own error code, but the thing is,
the case we care about is if link failed for a reason other
than that the final file has already existed (which would be
normal, or it could mean collision). So just check the error
code against EEXIST.
Signed-off-by: Junio C Hamano <junkio@cox.net>
FAT -- like Coda -- does not like cross-directory hard links. To be
precise, FAT does not like links at all. But links are not needed either.
So get rid of them.
Signed-off-by: Johannes Schindelin <Johannes.Schindelin@gmx.de>
Signed-off-by: Junio C Hamano <junkio@cox.net>
If we want to re-pack just local packfiles, we need to know whether a
particular object is local or not.
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Signed-off-by: Junio C Hamano <junkio@cox.net>
This starts using the "user.name" and "user.email" config variables if
they exist as the default name and email when committing. This means
that you don't have to use the GIT_COMMITTER_EMAIL environment variable
to override your email - you can just edit the config file instead.
The patch looks bigger than it is because it makes the default name and
email information non-static and renames it appropriately. And it moves
the common git environment variables into a new library file, so that
you can link against libgit.a and get the git environment without having
to link in zlib and libcrypt.
In short, most of it is renaming and moving, the real change core is
just a few new lines in "git_default_config()" that copies the user
config values to the new base.
It also changes "git-var -l" to list the config variables.
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Signed-off-by: Junio C Hamano <junkio@cox.net>
The http commit walker cannot use the same temporary file
creation code because it needs to use predictable temporary
filename for partial fetch continuation purposes, but the code
to move the temporary file to the final location should be
usable from the ordinary object creation codepath.
Export move_temp_to_file from sha1_file.c and use it, while
losing the custom relink_or_rename function from http-fetch.c.
Also the temporary object file creation part needs to make sure
the leading path exists, in preparation of the really lazy
fan-out directory creation.
Signed-off-by: Junio C Hamano <junkio@cox.net>
This makes it possible to have a "sparse" git object subdirectory
structure, something that has become much more attractive now that people
use pack-files all the time.
As a result of pack-files, a git object directory doesn't necessarily have
any individual objects lying around, and in that case it's just wasting
space to keep the empty first-level object directories around: on many
filesystems the 256 empty directories will be aboue 1MB of diskspace.
Even more importantly, after you re-pack a project that _used_ to be
unpacked, you could be left with huge directories that no longer contain
anything, but that waste space and take time to look through.
With this change, "git prune-packed" can just do an rmdir() on the
directories, and they'll get removed if empty, and re-created on demand.
This patch also tries to fix up "write_sha1_from_fd()" to use the new
common infrastructure for creating the object files, closing a hole where
we might otherwise leave half-written objects in the object database.
[jc: I unoptimized the part that really removes the fan-out directories
to ease transition. init-db still wastes 1MB of diskspace to hold 256
empty fan-outs, and prune-packed rmdir()'s the grown but empty directories,
but runs mkdir() immediately after that -- reducing the saving from 150KB
to 146KB. These parts will be re-introduced when everybody has the
on-demand capability.]
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Signed-off-by: Junio C Hamano <junkio@cox.net>
This adds more cruft to diff --git header to record the blob SHA1 and
the mode the patch/diff is intended to be applied against, to help the
receiving end fall back on a three-way merge. The new header looks
like this:
diff --git a/apply.c b/apply.c
index 7be5041..8366082 100644
--- a/apply.c
+++ b/apply.c
@@ -14,6 +14,7 @@
// files that are being modified, but doesn't apply the patch
// --stat does just a diffstat, and doesn't actually apply
+// --show-index-info shows the old and new index info for...
...
Upon receiving such a patch, if the patch did not apply cleanly to the
target tree, the recipient can try to find the matching old objects in
her object database and create a temporary tree, apply the patch to
that temporary tree, and attempt a 3-way merge between the patched
temporary tree and the target tree using the original temporary tree
as the common ancestor.
The patch lifts the code to compute the hash for an on-filesystem
object from update-index.c and makes it available to the diff output
routine.
Signed-off-by: Junio C Hamano <junkio@cox.net>
The core part detected and died upon seeing a corrupted packfile, but
did not help the user by telling which packfile is corrupt and how.
Signed-off-by: Junio C Hamano <junkio@cox.net>
An entry in the alternates file can name a directory relative to
the object store it describes. A typical linux-2.6 maintainer
repository would have "../../../torvalds/linux-2.6.git/objects" there,
because the subsystem maintainer object store would live in
/pub/scm/linux/kernel/git/$u/$system.git/objects/
and the object store of Linus tree is in
/pub/scm/linux/kernel/git/torvalds/linux-2.6.git/objects/
This unfortunately is different from GIT_ALTERNATE_OBJECT_DIRECTORIES
which is relative to the cwd of the running process, but there is no
way to make it consistent with the behaviour of the environment
variable. The process typically is run in $system.git/ directory for
a naked repository, or one level up for a repository with a working
tree, so we just define it to be relative to the objects/ directory
to be different from either ;-).
Later, the dumb transport could be updated to read from info/alternates
and make requests for the repository the repository borrows from.
Signed-off-by: Junio C Hamano <junkio@cox.net>
We have deprecated the old environment variable names for quite a
while and now it's time to remove them. Gone are:
SHA1_FILE_DIRECTORIES AUTHOR_DATE AUTHOR_EMAIL AUTHOR_NAME
COMMIT_AUTHOR_EMAIL COMMIT_AUTHOR_NAME SHA1_FILE_DIRECTORY
Signed-off-by: Junio C Hamano <junkio@cox.net>
Hi. This patch contains the following possible cleanups:
* Make some needlessly global functions in local-pull.c static
* Change 'char *' to 'const char *' where appropriate
Signed-off-by: Peter Hagervall <hager@cs.umu.se>
Signed-off-by: Junio C Hamano <junkio@cox.net>
Omitting the first branch in ?: is a GNU extension. Cute,
but not supported by other compilers. Replaced mostly
by explicit tests. Calls to getenv() simply are repeated
on non-GNU compilers.
Signed-off-by: Jason Riedy <ejr@cs.berkeley.edu>
Yes, using the same format for the file and the environment variable
was a big mistake. This uses LF as the path separator, and allows
lines that begin with '#' to be comments. ':' is no longer a separator
in objects/info/alternates file.
Signed-off-by: Junio C Hamano <junkio@cox.net>
Note that the pack file has to be in the usual location if it gets
installed later.
Signed-off-by: Daniel Barkalow <barkalow@iabervon.org>
Signed-off-by: Junio C Hamano <junkio@cox.net>
It was a mistake to use GIT_ALTERNATE_OBJECT_DIRECTORIES
environment variable to specify what alternate object pools to
look for missing objects when working with an object database.
It is not a property of the process running the git commands,
but a property of the object database that is partial and needs
other object pools to complete the set of objects it lacks.
This patch allows you to have $GIT_OBJECT_DIRECTORY/info/alternates
whose contents is in exactly the same format as the environment
variable, to let an object database name alternate object pools
it depends on.
Signed-off-by: Junio C Hamano <junkio@cox.net>
This patch fixes the only warning reported by gcc 4.0.1 on Fedora Core 4
for x86_64:
sha1_file.c:1391: warning: pointer targets in assignment differ in
signedness
Signed-off-by: Pavel Roskin <proski@gnu.org>
Signed-off-by: Junio C Hamano <junkio@cox.net>
If the object to write was packed, both its uncompressed and compressed
data were leaked. If the object was not packed, its file was not unmapped.
[jc: I think it still leaks on the write error path of
write_sha1_to_fd(), but that should be fixable in a small separate
patch.]
Signed-off-by: Sergey Vlasov <vsu@altlinux.ru>
Signed-off-by: Junio C Hamano <junkio@cox.net>
When following a reference, read_object_with_reference() did not free the
intermediate object data.
Signed-off-by: Sergey Vlasov <vsu@altlinux.ru>
Signed-off-by: Junio C Hamano <junkio@cox.net>
Everybody envies rev-parse, who is the only one that can grok
the extended sha1 format. Move the get_extended_sha1() out of
rev-parse, rename it to get_sha1() and make it available to
everybody else.
The one I posted earlier to the list had one bug where it did
not handle a name that ends with a digit correctly (it
incorrectly tried the "Nth parent" path). This commit fixes it.
Signed-off-by: Junio C Hamano <junkio@cox.net>
This causes ssh-pull to request objects in prefetch() and read then in
fetch(), such that it reduces the unpipelined round-trip time.
This also makes sha1_write_from_fd() support having a buffer of data
which it accidentally read from the fd after the object; this was
formerly not a problem, because it would always get a short read at
the end of an object, because the next object had not been
requested. This is no longer true.
Signed-off-by: Daniel Barkalow <barkalow@iabervon.org>
Signed-off-by: Junio C Hamano <junkio@cox.net>
This adds support for reading an uninstalled index, and installing a
pack file that was added while the program was running, as well as
functions for determining where to put the file.
Signed-off-by: Daniel Barkalow <barkalow@iabervon.org>
Signed-off-by: Junio C Hamano <junkio@cox.net>
Introduce a new file $GIT_DIR/info/grafts (or $GIT_GRAFT_FILE)
which is a list of "fake commit parent records". Each line of
this file is a commit ID, followed by parent commit IDs, all
40-byte hex SHA1 separated by a single SP in between. The
records override the parent information we would normally read
from the commit objects, allowing both adding "fake" parents
(i.e. grafting), and pretending as if a commit is not a child of
some of its real parents (i.e. cauterizing).
Signed-off-by: Junio C Hamano <junkio@cox.net>
I have reviewed all occurrences of mmap() in git and fixed three types
of errors/defects:
1) The result is not checked.
2) The file descriptor is closed if mmap() succeeds, but not when it
fails.
3) Various casts applied to -1 are used instead of MAP_FAILED, which is
specifically defined to check mmap() return value.
[jc: This is a second round of Pavel's patch. He fixed up the problem
that close() potentially clobbering the errno from mmap, which
the first round had.]
Signed-off-by: Pavel Roskin <proski@gnu.org>
Signed-off-by: Junio C Hamano <junkio@cox.net>
This reverses the order of object lookup, to check pack index first and
then go to the filesystem to find .git/objects/??/ hierarchy.
When most of the objects are packed, this saves quite many stat() calls
and negative dcache entries; while the price this approach has to pay is
negligible, even when most of the objects are outside pack, because
checking pack index file is quite cheap.
Signed-off-by: Junio C Hamano <junkio@cox.net>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Add write_sha1_to_fd(), which writes an object to a file descriptor. This
includes support for unpacking it and recompressing it.
Signed-off-by: Daniel Barkalow <barkalow@iabervon.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This patch makes the first half of write_sha1_file() and
index_fd() externally visible, to allow callers to compute the
object ID without actually storing it in the object database.
[JC demangled the whitespaces himself because he liked the patch
so much, and reworked the interface to index_fd() slightly,
taking suggestion from Linus and of his own.]
Signed-off-by: Bryan Larsen <bryan.larsen@gmail.com>
Signed-off-by: Junio C Hamano <junkio@cox.net>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
The function write_one_ref() is passed the list of refs received
from the other end, which was obtained by directory traversal
under $GIT_DIR/refs; this can contain paths other than what
git-init-db prepares and would fail to clone when there is
such.
Signed-off-by: Junio C Hamano <junkio@cox.net>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
The function calls opendir() without a matching closedir().
Signed-off-by: Junio C Hamano <junkio@cox.net>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
GIT_DIR=. ends up being what some of the pack senders use, and we
sometimes messed up when cleaning up the path, ie a ".//HEAD" was
cleaned up into "/HEAD", not "HEAD" like it should be.
We should do some other cleanup, and probably also verify that symlinks
don't point to outside the git area.
"git_path()" returns a static pathname pointer into the git directory
using a printf-like format specifier.
"head_ref()" works like "for_each_ref()", except for just the HEAD.
This implements show_pack_info() function used in verify-pack
command when -v flag is used to obtain something like
unpack-objects used to give when it was first written.
It shows the following for each non-deltified object found in
the pack:
SHA1 type size offset
For deltified objects, it shows this instead:
SHA1 type size offset depth base_sha1
In order to get the output in the order that appear in the pack
file for debugging purposes, you can do this:
$ git-verify-pack -v packfile | sort -n -k 4,4
Signed-off-by: Junio C Hamano <junkio@cox.net>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Nico pointed out that having verify_pack.c and verify-pack.c was
confusing. Rename verify_pack.c to pack-check.c as suggested,
and enhances the verification done quite a bit.
- Built-in sha1_file unpacking knows that a base object of a
deltified object _must_ be in the same pack, and takes
advantage of that fact.
- Earlier verify-pack command only checked the SHA1 sum for the
entire pack file and did not look into its contents. It now
checks everything idx file claims to have unpacks correctly.
- It now has a hook to give more detailed information for
objects contained in the pack under -v flag.
Signed-off-by: Junio C Hamano <junkio@cox.net>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This teaches packed_delta_info() that it only needs to look at
the type of the base object to figure out both type and size of
a deltified object. This saves quite a many calls to inflate()
when dealing with a deep delta chain.
Signed-off-by: Junio C Hamano <junkio@cox.net>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Given a list of <pack>.idx files, this command validates the
index file and the corresponding .pack file for consistency.
This patch also uses the same validation mechanism in fsck-cache
when the --full flag is used.
During normal operation, sha1_file.c verifies that a given .idx
file matches the .pack file by comparing the SHA1 checksum
stored in .idx file and .pack file as a minimum sanity check.
We may further want to check the pack signature and version when
we map the pack, but that would be a separate patch.
Earlier, errors to map a pack file was not flagged fatal but led
to a random fatal error later. This version explicitly die()s
when such an error is detected.
Signed-off-by: Junio C Hamano <junkio@cox.net>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
If we prefer 0 as maxsize for diff_delta() to say "unlimited", let's be
consistent about it.
This patch also fixes type mismatch in a call to get_delta_hdr_size()
from packed_delta_info().
Signed-off-by: Junio C Hamano <junkio@cox.net>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This is a wrap-up patch including all the cleanups I've done to the
delta code and its usage. The most important change is the
factorization of the delta header handling code.
Signed-off-by: Nicolas Pitre <nico@cam.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This makes it match the new delta encoding, and admittedly makes the
code easier to follow.
This also updates the PACK file version to 2, since this (and the delta
encoding change in the previous commit) are incompatible with the old
format.
The commands git-fsck-cache and probably git-*-pull needs to have a way
to enumerate objects contained in packed GIT archives and alternate
object pools. This commit exposes the data structure used to keep track
of them from sha1_file.c, and adds a couple of accessor interface
functions for use by the enhanced git-fsck-cache command.
Signed-off-by: Junio C Hamano <junkio@cox.net>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This was causing random segfaults, because use_packed_git() got
confused by random garbage there.
Signed-off-by: Junio C Hamano <junkio@cox.net>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This also adds a header with a signature, version info, and the number
of objects to the pack file. It also encodes the file length and type
more efficiently.
The initial one was not doing enough to figure things out
without uncompressing too much. It also fixes a potential
segfault resulting from missing use_packed_git() call.
We would need to introduce unuse_packed_git() call and do proper
use counting to figure out when it is safe to unmap, but
currently we do not unmap packed file yet.
Signed-off-by: Junio C Hamano <junkio@cox.net>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Now, there's still a misfeature there, which is that when you
create a new object, it doesn't check whether that object
already exists in the pack-file, so you'll end up with a few
recent objects that you really don't need (notably tree
objects), and this patch fixes it.
Signed-off-by: Junio C Hamano <junkio@cox.net>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
GIT_OBJECT_DIRECTORY and GIT_ALTERNATE_OBJECT_DIRECTORIES can
have the "pack" subdirectory that houses "packed GIT" files
produced by git-pack-objects (e.g. .git/objects/pack/foo.pack
and .git/objects/pack/foo.idx; always store them as pairs). The
following functions in sha1_file.c can then read object contents
from such packed file:
- sha1_object_info()
- has_sha1_file()
- read_sha1_file()
Signed-off-by: Junio C Hamano <junkio@cox.net>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This lets us eliminate one use of map_sha1_file() outside
sha1_file.c, to bring us one step closer to the packed GIT.
Signed-off-by: Junio C Hamano <junkio@cox.net>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Packed delta files created by git-pack-objects seems to be the
way to go, and existing "delta" object handling code has exposed
the object representation details to too many places. Remove it
while we refactor code to come up with a proper interface in
sha1_file.c.
Signed-off-by: Junio C Hamano <junkio@cox.net>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Here is a patch that fixes several gcc4 warnings about different signedness,
all between char and unsigned char. I tried to keep the patch minimal
so resertod to casts in three places.
Signed-off-by: Mika Kukkonen <mikukkon@iki.fi>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Make 'sha1' parameters const where possible
Signed-off-by: Jason McMullan <jason.mcmullan@timesys.com>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This patch adds code to read a hash out of a specified file under
{GIT_DIR}/refs/, and to write such files atomically and optionally with an
compare and lock.
Signed-off-by: Daniel Barkalow <barkalow@iabervon.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This adds sha1_file_size() helper function and uses it in the
rename/copy similarity estimator. The helper function handles
deltified object as well.
Signed-off-by: Junio C Hamano <junkio@cox.net>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
When a remote repository is deltified, we need to get the
objects that a deltified object we want to obtain is based upon.
The initial parts of each retrieved SHA1 file is inflated and
inspected to see if it is deltified, and its base object is
asked from the remote side when it is. Since this partial
inflation and inspection has a small performance hit, it can
optionally be skipped by giving -d flag to git-*-pull commands.
This flag should be used only when the remote repository is
known to have no deltified objects.
Rsync transport does not have this problem since it fetches
everything the remote side has.
Signed-off-by: Junio C Hamano <junkio@cox.net>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Make a separate helper for parsing the header of an object file
(really carefully) and for unpacking the rest. This means that
anybody who uses the "unpack_sha1_header()" interface can easily
look at the header and decide to unpack the rest too, without
doing any extra work.
It's for people who aren't necessarily interested in the whole
unpacked file, but do want to know the header information (size,
type, etc..)
For example, the delta code can use this to figure out whether
an object is already a delta object, and what it is a delta
against, without actually bothering to unpack all of the actual
data in the delta.
Add <limits.h> to the include files handled by "cache.h", and remove
extraneous #include directives from various .c files. The rule is that
"cache.h" gets all the basic stuff, so that we'll have as few system
dependencies as possible.
This makes the core code aware of delta objects and undeltafy them as
needed. The convention is to use read_sha1_file() to have
undeltafication done automatically (most users do that already so this
is transparent).
If the delta object itself has to be accessed then it must be done
through map_sha1_file() and unpack_sha1_file().
In that context mktag.c has been switched to read_sha1_file() as there
is no reason to do the full map+unpack manually.
Signed-off-by: Nicolas Pitre <nico@cam.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Fix various things that sparse complains about:
- use NULL instead of 0
- make sure we declare everything properly, or mark it static
- use proper function declarations ("fn(void)" instead of "fn()")
Sparse is always right.
- Raw hashes should be unsigned char.
- String functions want signed char.
- Hash and compress functions want unsigned char.
Signed-off By: Brian Gerst <bgerst@didntduck.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
During the mailing list discussion on renaming GIT_ environment
variables, people felt that having one environment that lets the
user (or Porcelain) specify both SHA1_FILE_DIRECTORY (now
GIT_OBJECT_DIRECTORY) and GIT_INDEX_FILE for the default layout
would be handy. This change introduces GIT_DIR environment
variable, from which the defaults for GIT_INDEX_FILE and
GIT_OBJECT_DIRECTORY are derived. When GIT_DIR is not defined,
it defaults to ".git". GIT_INDEX_FILE defaults to
"$GIT_DIR/index" and GIT_OBJECT_DIRECTORY defaults to
"$GIT_DIR/objects".
Special thanks for ideas and discussions go to Petr Baudis and
Daniel Barkalow. Bugs are mine ;-)
Signed-off-by: Junio C Hamano <junkio@cox.net>
H. Peter Anvin mentioned that using SHA1_whatever as an
environment variable name is not nice and we should instead use
names starting with "GIT_" prefix to avoid conflicts. Here is
what this patch does:
* Renames the following environment variables:
New name Old Name
GIT_AUTHOR_DATE AUTHOR_DATE
GIT_AUTHOR_EMAIL AUTHOR_EMAIL
GIT_AUTHOR_NAME AUTHOR_NAME
GIT_COMMITTER_EMAIL COMMIT_AUTHOR_EMAIL
GIT_COMMITTER_NAME COMMIT_AUTHOR_NAME
GIT_ALTERNATE_OBJECT_DIRECTORIES SHA1_FILE_DIRECTORIES
GIT_OBJECT_DIRECTORY SHA1_FILE_DIRECTORY
* Introduces a compatibility macro, gitenv(), which does an
getenv() and if it fails calls gitenv_bc(), which in turn
picks up the value from old name while giving a warning about
using an old name.
* Changes all users of the environment variable to fetch
environment variable with the new name using gitenv().
* Updates the documentation and scripts shipped with Linus GIT
distribution.
The transition plan is as follows:
* We will keep the backward compatibility list used by gitenv()
for now, so the current scripts and user environments
continue to work as before. The users will get warnings when
they have old name but not new name in their environment to
the stderr.
* The Porcelain layers should start using new names. However,
just in case it ends up calling old Plumbing layer
implementation, they should also export old names, taking
values from the corresponding new names, during the
transition period.
* After a transition period, we would drop the compatibility
support and drop gitenv(). Revert the callers to directly
call getenv() but keep using the new names.
The last part is probably optional and the transition
duration needs to be set to a reasonable value.
Signed-off-by: Junio C Hamano <junkio@cox.net>
This fixes stylistic problems and one unused variable spotted by
Petr Baudis. The buf variable unused in prepare_alt_odb() is
gone and the "creepy" function is more heavily documented.
Signed-off-by: Junio C Hamano <junkio@cox.net>
A deflate loop in sha1_file.c would have /* nothing */ as its
body, but the semicolon was missing, so the next command was run.
Fortunately the loop went through exactly once so it didn't trigger
an actual bug so far.
Signed-Off-by: Thomas Glanzmann <sithglan@stud.uni-erlangen.de>
Signed-off-by: Petr Baudis <pasky@ucw.cz>
<JC> Editorial Note. We may want to include standard headers in one
of those headers everybody includes, e.g. cache.h, to reduce clutters,
but this commit is as Thomas posted to the GIT list.
Date: Sat, 7 May 2005 10:41:41 +0200
Signed-off-by: Thomas Glanzmann <sithglan@stud.uni-erlangen.de>
Signed-off-by: Junio C Hamano <junkio@cox.net>
This does not matter for commands that write just a handful SHA1 files,
but is noticeable in git-convert-cache which essentially traverses the
entire object database.
Signed-off-by: Junio C Hamano <junkio@cox.net>
SHA1_FILE_DIRECTORIES environment variable is a colon separated paths
used when looking for SHA1 files not found in the usual place for
reading. Creating a new SHA1 file does not use this alternate object
database location mechanism. This is useful to archive older, rarely
used objects into separate directories.
Signed-off-by: Junio C Hamano <junkio@cox.net>
Make it much safer: we write to a temporary file, and then link that
temporary file to the final destination. This avoids all the nasty
races if several people write the same object at the same time.
It should also result in nicer on-disk layout, since it means that
objects all get created in the same subdirectory. That makes a lot
of block allocation algorithms happier, since the objects will now
be allocated from the same zone.
A new command, git-write-blob, is introduced. This registers
the contents of any file on the filesystem as a blob in the
object database and reports its SHA1 to the standard output.
To implement it, the patch promotes index_fd() from a static
function in update-cache.c to extern and moves it to a library
source, sha1_file.c.
This command is used to update git-merge-one-file-script so that
it does not smudge the work tree.
Signed-off-by: Junio C Hamano <junkio@cox.net>
If somebody wants it later, we can re-do it, but for now we consider
it an experiment that wasn't worth it. Git will still honor symbolic
names, it just won't look up parents for you.
Of course, you can always do it by hand if you want to.
It uses the jit syntax, at least for now. 0-xxxx is the first parent of xxxx,
while 1-xxxx is the second, and so on. You can use just "-xxxx" for the first
parent, but a lot of commands will think that the initial '-' implies a
command line flag.
This allows the programs to use various simplified versions of
the SHA1 names, eg just say "HEAD" for the SHA1 pointed to by
the .git/HEAD file etc.
For example, this commit has been done with
git-commit-tree $(git-write-tree) -p HEAD
instead of the traditional "$(cat .git/HEAD)" syntax.
This patch renames read_tree_with_tree_or_commit_sha1() to
read_object_with_reference() and extends it to automatically
dereference not just "commit" objects but "tag" objects. With
this patch, you can say e.g.:
ls-tree $tag
read-tree -m $(merge-base $tag $HEAD) $tag $HEAD
diff-cache $tag
diff-tree $tag $HEAD
Signed-off-by: Junio C Hamano <junkio@cox.net>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Introduce xmalloc and xrealloc to die gracefully with a descriptive
message when out of memory, rather than taking a SIGSEGV.
Signed-off-by: Christopher Li<chrislgit@chrisli.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Here is how to trigger it:
echo blob 100 > .git/objects/00/ae4e8d3208e09f2cf7a38202a126f728cadb49
Then run fsck-cache. It will try to unpack after the header to calculate
the hash, inflate returns total_out == 0 and memcpy() dies.
The patch below seems to work with ZLIB 1.1 and 1.2.
Signed-off-by: Andreas Gal <gal@uci.edu>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This adds two functions: one to check if an object is present in the local
database, and one to add an object to the local database by reading it
from a file descriptor and checking its hash.
Signed-Off-By: Daniel Barkalow <barkalow@iabervon.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
We really don't care about atime, and it sucks to dirty the
inode cache just for it.
This is more than a one-liner only because we need to be able to
clear the O_NOATIME flag in case some of the objects are owned
by others (in which case open will return EPERM), and because not
everybody has the O_NOATIME flag.
This patch implements read_tree_with_tree_or_commit_sha1(),
which can be used when you are interested in reading an unpacked
raw tree data but you do not know nor care if the SHA1 you
obtained your user is a tree ID or a commit ID. Before this
function's introduction, you would have called read_sha1_file(),
examined its type, parsed it to call read_sha1_file() again if
it is a commit, and verified that the resulting object is a
tree. Instead, this function does that for you. It returns
NULL if the given SHA1 is not either a tree or a commit.
Signed-off-by: Junio C Hamano <junkio@cox.net>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
