Commit Graph

501 Commits

Author SHA1 Message Date
Linus Torvalds
e8bd78c3fc close_sha1_file(): make it easier to diagnose errors
A bug report with "unable to write sha1 file" made us realize that we do
not have enough information to guess why close() is failing.

Signed-off-by: Junio C Hamano <gitster@pobox.com>
2009-03-24 14:39:20 -07:00
Brandon Casey
4d6acb7041 Remove --kept-pack-only option and associated infrastructure
This option to pack-objects/rev-list was created to improve the -A and -a
options of repack.  It was found to be lacking in that it did not provide
the ability to differentiate between local and non-local kept packs, and
found to be unnecessary since objects residing in local kept packs can be
filtered out by the --honor-pack-keep option.

Signed-off-by: Brandon Casey <casey@nrlssc.navy.mil>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2009-03-20 13:32:33 -07:00
Junio C Hamano
aec813062b Merge branch 'jc/maint-1.6.0-keep-pack'
* jc/maint-1.6.0-keep-pack:
  is_kept_pack(): final clean-up
  Simplify is_kept_pack()
  Consolidate ignore_packed logic more
  has_sha1_kept_pack(): take "struct rev_info"
  has_sha1_pack(): refactor "pretend these packs do not exist" interface
  git-repack: resist stray environment variable
2009-03-11 13:49:56 -07:00
Junio C Hamano
69e020ae00 is_kept_pack(): final clean-up
Now is_kept_pack() is just a member lookup into a structure, we can write
it as such.

Also rewrite the sole caller of has_sha1_kept_pack() to switch on the
criteria the callee uses (namely, revs->kept_pack_only) between calling
has_sha1_kept_pack() and has_sha1_pack(), so that these two callees do not
have to take a pointer to struct rev_info as an argument.

This removes the header file dependency issue temporarily introduced by
the earlier commit, so we revert changes associated to that as well.

Signed-off-by: Junio C Hamano <gitster@pobox.com>
2009-02-28 01:06:06 -08:00
Junio C Hamano
03a9683d22 Simplify is_kept_pack()
This removes --unpacked=<packfile> parameter from the revision parser, and
rewrites its use in git-repack to pass a single --kept-pack-only option
instead.

The new --kept-pack-only option means just that.  When this option is
given, is_kept_pack() that used to say "not on the --unpacked=<packfile>
list" now says "the packfile has corresponding .keep file".

Signed-off-by: Junio C Hamano <gitster@pobox.com>
2009-02-28 01:06:06 -08:00
Junio C Hamano
386cb77210 Consolidate ignore_packed logic more
This refactors three loops that check if a given packfile is on the
ignore_packed list into a function is_kept_pack().  The function returns
false for a pack on the list, and true for a pack not on the list, because
this list is solely used by "git repack" to pass list of packfiles that do
not have corresponding .keep files, i.e. a packfile not on the list is
"kept".

Signed-off-by: Junio C Hamano <gitster@pobox.com>
2009-02-28 01:06:06 -08:00
Junio C Hamano
b8431b033f has_sha1_kept_pack(): take "struct rev_info"
Its "ignore_packed" parameter always comes from struct rev_info.  This
patch makes the function take a pointer to the surrounding structure, so
that the refactoring in the next patch becomes easier to review.

There is an unfortunate header file dependency and the easiest workaround
is to temporarily move the function declaration from cache.h to
revision.h; this will be moved back to cache.h once the function loses
this "ignore_packed" parameter altogether in the later part of the
series.

Signed-off-by: Junio C Hamano <gitster@pobox.com>
2009-02-28 01:06:06 -08:00
Junio C Hamano
cd673c1f17 has_sha1_pack(): refactor "pretend these packs do not exist" interface
Most of the callers of this function except only one pass NULL to its last
parameter, ignore_packed.

Introduce has_sha1_kept_pack() function that has the function signature
and the semantics of this function, and convert the sole caller that does
not pass NULL to call this new function.

All other callers and has_sha1_pack() lose the ignore_packed parameter.

Signed-off-by: Junio C Hamano <gitster@pobox.com>
2009-02-28 01:06:06 -08:00
Felipe Contreras
a9d98a148d sha1_file.c: fix typo
it's != its

Signed-off-by: Felipe Contreras <felipe.contreras@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2009-02-25 00:49:54 -08:00
Junio C Hamano
30aa4fb15f Merge branch 'maint'
* maint:
  Prepare for 1.6.1.4.
  Make repack less likely to corrupt repository
  fast-export: ensure we traverse commits in topological order
  Clear the delta base cache if a pack is rebuilt

Conflicts:
	RelNotes
2009-02-11 18:47:30 -08:00
Junio C Hamano
7a134dbbc9 Merge branch 'maint-1.6.0' into maint
* maint-1.6.0:
  Make repack less likely to corrupt repository
  fast-export: ensure we traverse commits in topological order
  Clear the delta base cache if a pack is rebuilt
2009-02-11 18:32:37 -08:00
Shawn O. Pearce
fa3a0c94dc Clear the delta base cache if a pack is rebuilt
There is some risk that re-opening a regenerated pack file with
different offsets could leave stale entries within the delta base
cache that could be matched up against other objects using the same
"struct packed_git*" and pack offset.

Throwing away the entire delta base cache in this case is safer,
as we don't have to worry about a recycled "struct packed_git*"
matching to the wrong base object, resulting in delta apply
errors while unpacking an object.

Suggested-by: Daniel Barkalow <barkalow@iabervon.org>
Signed-off-by: Shawn O. Pearce <spearce@spearce.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2009-02-11 10:25:24 -08:00
Junio C Hamano
fd8475d9fb Merge branch 'maint'
* maint:
  Clear the delta base cache during fast-import checkpoint
2009-02-10 21:30:45 -08:00
Junio C Hamano
9b27ea9518 Merge branch 'maint-1.6.0' into maint
* maint-1.6.0:
  Clear the delta base cache during fast-import checkpoint
2009-02-10 15:32:26 -08:00
Shawn O. Pearce
3d20c636af Clear the delta base cache during fast-import checkpoint
Otherwise we may reuse the same memory address for a totally
different "struct packed_git", and a previously cached object from
the prior occupant might be returned when trying to unpack an object
from the new pack.

Found-by: Daniel Barkalow <barkalow@iabervon.org>
Signed-off-by: Shawn O. Pearce <spearce@spearce.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2009-02-10 15:30:59 -08:00
Junio C Hamano
141b6b83d7 Merge branch 'lt/maint-wrap-zlib' into maint
* lt/maint-wrap-zlib:
  Wrap inflate and other zlib routines for better error reporting

Conflicts:
	http-push.c
	http-walker.c
	sha1_file.c
2009-02-05 18:01:00 -08:00
Junio C Hamano
8c95d3c31b Sync with 1.6.1.2
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2009-01-29 00:32:52 -08:00
Junio C Hamano
8561b522d7 Merge branch 'maint-1.6.0' into maint
* maint-1.6.0:
  avoid 31-bit truncation in write_loose_object
2009-01-28 23:41:28 -08:00
Jeff King
915308b187 avoid 31-bit truncation in write_loose_object
The size of the content we are adding may be larger than
2.1G (i.e., "git add gigantic-file"). Most of the code-path
to do so uses size_t or unsigned long to record the size,
but write_loose_object uses a signed int.

On platforms where "int" is 32-bits (which includes x86_64
Linux platforms), we end up passing malloc a negative size.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2009-01-28 23:40:53 -08:00
Junio C Hamano
36dd939393 Merge branch 'lt/maint-wrap-zlib'
* lt/maint-wrap-zlib:
  Wrap inflate and other zlib routines for better error reporting

Conflicts:
	http-push.c
	http-walker.c
	sha1_file.c
2009-01-21 16:55:17 -08:00
Christian Couder
c2c5b27051 sha1_file: make "read_object" static
This function is only used from "sha1_file.c".

And as we want to add a "replace_object" hook in "read_sha1_file",
we must not let people bypass the hook using something other than
"read_sha1_file".

Signed-off-by: Christian Couder <chriscool@tuxfamily.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2009-01-13 00:14:55 -08:00
Linus Torvalds
39c68542fc Wrap inflate and other zlib routines for better error reporting
R. Tyler Ballance reported a mysterious transient repository corruption;
after much digging, it turns out that we were not catching and reporting
memory allocation errors from some calls we make to zlib.

This one _just_ wraps things; it doesn't do the "retry on low memory
error" part, at least not yet. It is an independent issue from the
reporting.  Some of the errors are expected and passed back to the caller,
but we die when zlib reports it failed to allocate memory for now.

Signed-off-by: Junio C Hamano <gitster@pobox.com>
2009-01-11 02:13:06 -08:00
Linus Torvalds
b760d3aa74 Make 'index_path()' use 'strbuf_readlink()'
This makes us able to properly index symlinks even on filesystems where
st_size doesn't match the true size of the link.

Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2008-12-17 13:36:34 -08:00
Junio C Hamano
de0db42278 Merge branch 'maint'
* maint:
  fsck: reduce stack footprint
  make sure packs to be replaced are closed beforehand
2008-12-11 00:36:31 -08:00
Nicolas Pitre
c74faea19e make sure packs to be replaced are closed beforehand
Especially on Windows where an opened file cannot be replaced, make
sure pack-objects always close packs it is about to replace. Even on
non Windows systems, this could save potential bad results if ever
objects were to be read from the new pack file using offset from the old
index.

This should fix t5303 on Windows.

Signed-off-by: Nicolas Pitre <nico@cam.org>
Tested-by: Johannes Sixt <j6t@kdbg.org> (MinGW)
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2008-12-10 17:56:05 -08:00
Junio C Hamano
0fd9d7e66d Merge branch 'bc/maint-keep-pack' into maint
* bc/maint-keep-pack:
  repack: only unpack-unreachable if we are deleting redundant packs
  t7700: test that 'repack -a' packs alternate packed objects
  pack-objects: extend --local to mean ignore non-local loose objects too
  sha1_file.c: split has_loose_object() into local and non-local counterparts
  t7700: demonstrate mishandling of loose objects in an alternate ODB
  builtin-gc.c: use new pack_keep bitfield to detect .keep file existence
  repack: do not fall back to incremental repacking with [-a|-A]
  repack: don't repack local objects in packs with .keep file
  pack-objects: new option --honor-pack-keep
  packed_git: convert pack_local flag into a bitfield and add pack_keep
  t7700: demonstrate mishandling of objects in packs with a .keep file
2008-12-02 23:00:04 -08:00
Junio C Hamano
455d0f5c23 Merge branch 'maint'
* maint:
  sha1_file.c: resolve confusion EACCES vs EPERM
  sha1_file: avoid bogus "file exists" error message
  git checkout: don't warn about unborn branch if -f is already passed
  bash: offer refs instead of filenames for 'git revert'
  bash: remove dashed command leftovers
  git-p4: fix keyword-expansion regex
  fast-export: use an unsorted string list for extra_refs
  Add new testcase to show fast-export does not always exports all tags
2008-11-27 19:23:51 -08:00
Sam Vilain
35243577ab sha1_file.c: resolve confusion EACCES vs EPERM
An earlier commit 916d081 (Nicer error messages in case saving an object
to db goes wrong, 2006-11-09) confused EACCES with EPERM, the latter of
which is an unlikely error from mkstemp().

Signed-off-by: Sam Vilain <sam@vilain.net>
2008-11-27 19:11:21 -08:00
Joey Hess
65117abc04 sha1_file: avoid bogus "file exists" error message
This avoids the following misleading error message:

error: unable to create temporary sha1 filename ./objects/15: File exists

mkstemp can fail for many reasons, one of which, ENOENT, can occur if
the directory for the temp file doesn't exist. create_tmpfile tried to
handle this case by always trying to mkdir the directory, even if it
already existed. This caused errno to be clobbered, so one cannot tell
why mkstemp really failed, and it truncated the buffer to just the
directory name, resulting in the strange error message shown above.

Note that in both occasions that I've seen this failure, it has not been
due to a missing directory, or bad permissions, but some other, unknown
mkstemp failure mode that did not occur when I ran git again. This code
could perhaps be made more robust by retrying mkstemp, in case it was a
transient failure.

Signed-off-by: Joey Hess <joey@kitenet.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2008-11-27 18:48:53 -08:00
Joey Hess
cbacbf4e55 sha1_file: avoid bogus "file exists" error message
This avoids the following misleading error message:

error: unable to create temporary sha1 filename ./objects/15: File exists

mkstemp can fail for many reasons, one of which, ENOENT, can occur if
the directory for the temp file doesn't exist. create_tmpfile tried to
handle this case by always trying to mkdir the directory, even if it
already existed. This caused errno to be clobbered, so one cannot tell
why mkstemp really failed, and it truncated the buffer to just the
directory name, resulting in the strange error message shown above.

Note that in both occasions that I've seen this failure, it has not been
due to a missing directory, or bad permissions, but some other, unknown
mkstemp failure mode that did not occur when I ran git again. This code
could perhaps be made more robust by retrying mkstemp, in case it was a
transient failure.

Signed-off-by: Joey Hess <joey@kitenet.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2008-11-23 19:44:19 -08:00
Alex Riesen
f755bb996b Fix handle leak in sha1_file/unpack_objects if there were damaged object data
In the case of bad packed object CRC, unuse_pack wasn't called after
check_pack_crc which calls use_pack.

Signed-off-by: Alex Riesen <raa.lkml@gmail.com>
Acked-by: Nicolas Pitre <nico@cam.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2008-11-23 19:31:05 -08:00
Junio C Hamano
47a792539a Merge branch 'jk/commit-v-strip'
* jk/commit-v-strip:
  status: show "-v" diff even for initial commit
  wt-status: refactor initial commit printing
  define empty tree sha1 as a macro
2008-11-16 00:48:59 -08:00
Junio C Hamano
7b51b77dbc Merge branch 'np/pack-safer'
* np/pack-safer:
  t5303: fix printf format string for portability
  t5303: work around printf breakage in dash
  pack-objects: don't leak pack window reference when splitting packs
  extend test coverage for latest pack corruption resilience improvements
  pack-objects: allow "fixing" a corrupted pack without a full repack
  make find_pack_revindex() aware of the nasty world
  make check_object() resilient to pack corruptions
  make packed_object_info() resilient to pack corruptions
  make unpack_object_header() non fatal
  better validation on delta base object offsets
  close another possibility for propagating pack corruption
2008-11-12 22:26:35 -08:00
Junio C Hamano
ecbbfb15a4 Merge branch 'bc/maint-keep-pack'
* bc/maint-keep-pack:
  t7700: test that 'repack -a' packs alternate packed objects
  pack-objects: extend --local to mean ignore non-local loose objects too
  sha1_file.c: split has_loose_object() into local and non-local counterparts
  t7700: demonstrate mishandling of loose objects in an alternate ODB
  builtin-gc.c: use new pack_keep bitfield to detect .keep file existence
  repack: do not fall back to incremental repacking with [-a|-A]
  repack: don't repack local objects in packs with .keep file
  pack-objects: new option --honor-pack-keep
  packed_git: convert pack_local flag into a bitfield and add pack_keep
  t7700: demonstrate mishandling of objects in packs with a .keep file
2008-11-12 22:00:43 -08:00
Jeff King
14d9c57896 define empty tree sha1 as a macro
This can potentially be used in a few places, so let's make
it available to all parts of the code.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2008-11-12 12:52:21 -08:00
Brandon Casey
0f4dc14ac4 sha1_file.c: split has_loose_object() into local and non-local counterparts
Signed-off-by: Brandon Casey <drafnel@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2008-11-12 10:29:22 -08:00
Brandon Casey
8d25931d6f packed_git: convert pack_local flag into a bitfield and add pack_keep
pack_keep will be set when a pack file has an associated .keep file.

Signed-off-by: Brandon Casey <casey@nrlssc.navy.mil>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2008-11-12 10:28:08 -08:00
Nicolas Pitre
08698b1e32 make find_pack_revindex() aware of the nasty world
It currently calls die() whenever given offset is not found thinking
that such thing should never happen.  But this offset may come from a
corrupted pack whych _could_ happen and not be found.  Callers should
deal with this possibility gracefully instead.

Signed-off-by: Nicolas Pitre <nico@cam.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2008-11-02 15:22:35 -08:00
Nicolas Pitre
3d77d8774f make packed_object_info() resilient to pack corruptions
In the same spirit as commit 8eca0b47ff, let's try to survive a pack
corruption by making packed_object_info() able to fall back to alternate
packs or loose objects.

Signed-off-by: Nicolas Pitre <nico@cam.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2008-11-02 15:22:35 -08:00
Nicolas Pitre
09ded04b7e make unpack_object_header() non fatal
It is possible to have pack corruption in the object header.  Currently
unpack_object_header() simply die() on them instead of letting the caller
deal with that gracefully.

So let's have unpack_object_header() return an error instead, and find
a better name for unpack_object_header_gently() in that context.  All
callers of unpack_object_header() are ready for it.

Signed-off-by: Nicolas Pitre <nico@cam.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2008-11-02 15:22:34 -08:00
Nicolas Pitre
d8f325563d better validation on delta base object offsets
In one case, it was possible to have a bad offset equal to 0 effectively
pointing a delta onto itself and crashing git after too many recursions.
In the other cases, a negative offset could result due to off_t being
signed.  Catch those.

Signed-off-by: Nicolas Pitre <nico@cam.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2008-11-02 15:22:34 -08:00
Nicolas Pitre
0e8189e270 close another possibility for propagating pack corruption
Abstract
--------

With index v2 we have a per object CRC to allow quick and safe reuse of
pack data when repacking.  This, however, doesn't currently prevent a
stealth corruption from being propagated into a new pack when _not_
reusing pack data as demonstrated by the modification to t5302 included
here.

The Context
-----------

The Git database is all checksummed with SHA1 hashes.  Any kind of
corruption can be confirmed by verifying this per object hash against
corresponding data.  However this can be costly to perform systematically
and therefore this check is often not performed at run time when
accessing the object database.

First, the loose object format is entirely compressed with zlib which
already provide a CRC verification of its own when inflating data.  Any
disk corruption would be caught already in this case.

Then, packed objects are also compressed with zlib but only for their
actual payload.  The object headers and delta base references are not
deflated for obvious performance reasons, however this leave them
vulnerable to potentially undetected disk corruptions.  Object types
are often validated against the expected type when they're requested,
and deflated size must always match the size recorded in the object header,
so those cases are pretty much covered as well.

Where corruptions could go unnoticed is in the delta base reference.
Of course, in the OBJ_REF_DELTA case,  the odds for a SHA1 reference to
get corrupted so it actually matches the SHA1 of another object with the
same size (the delta header stores the expected size of the base object
to apply against) are virtually zero.  In the OBJ_OFS_DELTA case, the
reference is a pack offset which would have to match the start boundary
of a different base object but still with the same size, and although this
is relatively much more "probable" than in the OBJ_REF_DELTA case, the
probability is also about zero in absolute terms.  Still, the possibility
exists as demonstrated in t5302 and is certainly greater than a SHA1
collision, especially in the OBJ_OFS_DELTA case which is now the default
when repacking.

Again, repacking by reusing existing pack data is OK since the per object
CRC provided by index v2 guards against any such corruptions. What t5302
failed to test is a full repack in such case.

The Solution
------------

As unlikely as this kind of stealth corruption can be in practice, it
certainly isn't acceptable to propagate it into a freshly created pack.
But, because this is so unlikely, we don't want to pay the run time cost
associated with extra validation checks all the time either.  Furthermore,
consequences of such corruption in anything but repacking should be rather
visible, and even if it could be quite unpleasant, it still has far less
severe consequences than actively creating bad packs.

So the best compromize is to check packed object CRC when unpacking
objects, and only during the compression/writing phase of a repack, and
only when not streaming the result.  The cost of this is minimal (less
than 1% CPU time), and visible only with a full repack.

Someone with a stats background could provide an objective evaluation of
this, but I suspect that it's bad RAM that has more potential for data
corruptions at this point, even in those cases where this extra check
is not performed.  Still, it is best to prevent a known hole for
corruption when recreating object data into a new pack.

What about the streamed pack case?  Well, any client receiving a pack
must always consider that pack as untrusty and perform full validation
anyway, hence no such stealth corruption could be propagated to remote
repositoryes already.  It is therefore worthless doing local validation
in that case.

Signed-off-by: Nicolas Pitre <nico@cam.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2008-11-02 15:22:15 -08:00
Junio C Hamano
581000a419 Merge branch 'jc/maint-co-track' into maint
* jc/maint-co-track:
  Enhance hold_lock_file_for_{update,append}() API
  demonstrate breakage of detached checkout with symbolic link HEAD
  Fix "checkout --track -b newbranch" on detached HEAD
2008-11-02 13:36:14 -08:00
Junio C Hamano
a157400c97 Merge branch 'jc/maint-co-track'
* jc/maint-co-track:
  Enhance hold_lock_file_for_{update,append}() API
  demonstrate breakage of detached checkout with symbolic link HEAD
  Fix "checkout --track -b newbranch" on detached HEAD

Conflicts:
	builtin-commit.c
2008-10-21 17:58:11 -07:00
Junio C Hamano
acd3b9eca8 Enhance hold_lock_file_for_{update,append}() API
This changes the "die_on_error" boolean parameter to a mere "flags", and
changes the existing callers of hold_lock_file_for_update/append()
functions to pass LOCK_DIE_ON_ERROR.

Signed-off-by: Junio C Hamano <gitster@pobox.com>
2008-10-19 12:35:37 -07:00
Junio C Hamano
58e0fa5416 Merge branch 'maint'
* maint:
  Hopefully the final draft release notes update before 1.6.0.3
  diff(1): clarify what "T"ypechange status means
  contrib: update packinfo.pl to not use dashed commands
  force_object_loose: Fix memory leak
  tests: shell negation portability fix
2008-10-18 08:26:44 -07:00
Björn Steinbrink
1fb23e6550 force_object_loose: Fix memory leak
read_packed_sha1 expectes its caller to free the buffer it returns, which
force_object_loose didn't do.

This leak is eventually triggered by "git gc", when it is manually invoked
or there are too many packs around, making gc totally unusable when there
are lots of unreachable objects.

Signed-off-by: Björn Steinbrink <B.Steinbrink@gmx.de>
Acked-by: Nicolas Pitre <nico@cam.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2008-10-18 06:19:06 -07:00
Brandon Casey
f285a2d7ed Replace calls to strbuf_init(&foo, 0) with STRBUF_INIT initializer
Many call sites use strbuf_init(&foo, 0) to initialize local
strbuf variable "foo" which has not been accessed since its
declaration. These can be replaced with a static initialization
using the STRBUF_INIT macro which is just as readable, saves a
function call, and takes up fewer lines.

Signed-off-by: Brandon Casey <casey@nrlssc.navy.mil>
Signed-off-by: Shawn O. Pearce <spearce@spearce.org>
2008-10-12 12:36:19 -07:00
Miklos Vajna
749bc58c5e Cleanup in sha1_file.c::cache_or_unpack_entry()
This patch just removes an unnecessary goto which makes the code easier
to read and shorter.

Signed-off-by: Miklos Vajna <vmiklos@frugalware.org>
Signed-off-by: Shawn O. Pearce <spearce@spearce.org>
2008-10-09 08:55:42 -07:00
Nicolas Pitre
9126f0091f fix openssl headers conflicting with custom SHA1 implementations
On ARM I have the following compilation errors:

    CC fast-import.o
In file included from cache.h:8,
                 from builtin.h:6,
                 from fast-import.c:142:
arm/sha1.h:14: error: conflicting types for 'SHA_CTX'
/usr/include/openssl/sha.h:105: error: previous declaration of 'SHA_CTX' was here
arm/sha1.h:16: error: conflicting types for 'SHA1_Init'
/usr/include/openssl/sha.h:115: error: previous declaration of 'SHA1_Init' was here
arm/sha1.h:17: error: conflicting types for 'SHA1_Update'
/usr/include/openssl/sha.h:116: error: previous declaration of 'SHA1_Update' was here
arm/sha1.h:18: error: conflicting types for 'SHA1_Final'
/usr/include/openssl/sha.h:117: error: previous declaration of 'SHA1_Final' was here
make: *** [fast-import.o] Error 1

This is because openssl header files are always included in
git-compat-util.h since commit 684ec6c63c whenever NO_OPENSSL is not
set, which somehow brings in <openssl/sha1.h> clashing with the custom
ARM version.  Compilation of git is probably broken on PPC too for the
same reason.

Turns out that the only file requiring openssl/ssl.h and openssl/err.h
is imap-send.c.  But only moving those problematic includes there
doesn't solve the issue as it also includes cache.h which brings in the
conflicting local SHA1 header file.

As suggested by Jeff King, the best solution is to rename our references
to SHA1 functions and structure to something git specific, and define those
according to the implementation used.

Signed-off-by: Nicolas Pitre <nico@cam.org>
Signed-off-by: Shawn O. Pearce <spearce@spearce.org>
2008-10-02 18:06:56 -07:00
Shawn O. Pearce
1ad6d46235 Merge branch 'jc/alternate-push'
* jc/alternate-push:
  push: receiver end advertises refs from alternate repositories
  push: prepare sender to receive extended ref information from the receiver
  receive-pack: make it a builtin
  is_directory(): a generic helper function
2008-09-25 09:39:24 -07:00
Shawn O. Pearce
58245a5e40 Merge branch 'jc/safe-c-l-d'
* jc/safe-c-l-d:
  safe_create_leading_directories(): make it about "leading" directories
2008-09-25 08:50:01 -07:00
Junio C Hamano
3791f77c28 Merge branch 'maint'
* maint:
  sha1_file: link() returns -1 on failure, not errno
  Make git archive respect core.autocrlf when creating zip format archives
  Add new test to demonstrate git archive core.autocrlf inconsistency
  gitweb: avoid warnings for commits without body
  Clarified gitattributes documentation regarding custom hunk header.
  git-svn: fix handling of even funkier branch names
  git-svn: Always create a new RA when calling do_switch for svn://
  git-svn: factor out svnserve test code for later use
  diff/diff-files: do not use --cc too aggressively
2008-09-18 20:30:12 -07:00
Thomas Rast
e32c0a9c38 sha1_file: link() returns -1 on failure, not errno
5723fe7 (Avoid cross-directory renames and linking on object creation,
2008-06-14) changed the call to use link() directly instead of through a
custom wrapper, but forgot that it returns 0 or -1, not 0 or errno.

Signed-off-by: Thomas Rast <trast@student.ethz.ch>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2008-09-18 19:51:13 -07:00
Junio C Hamano
d79796bcf0 push: receiver end advertises refs from alternate repositories
Earlier, when pushing into a repository that borrows from alternate object
stores, we followed the longstanding design decision not to trust refs in
the alternate repository that houses the object store we are borrowing
from.  If your public repository is borrowing from Linus's public
repository, you pushed into it long time ago, and now when you try to push
your updated history that is in sync with more recent history from Linus,
you will end up sending not just your own development, but also the
changes you acquired through Linus's tree, even though the objects needed
for the latter already exists at the receiving end.  This is because the
receiving end does not advertise that the objects only reachable from the
borrowed repository (i.e. Linus's) are already available there.

This solves the issue by making the receiving end advertise refs from
borrowed repositories.  They are not sent with their true names but with a
phoney name ".have" to make sure that the old senders will safely ignore
them (otherwise, the old senders will misbehave, trying to push matching
refs, and mirror push that deletes refs that only exist at the receiving
end).

Signed-off-by: Junio C Hamano <gitster@pobox.com>
2008-09-09 09:27:46 -07:00
Junio C Hamano
90b4a71c49 is_directory(): a generic helper function
A simple "grep -e stat --and -e S_ISDIR" revealed there are many
open-coded implementations of this function.

Signed-off-by: Junio C Hamano <gitster@pobox.com>
2008-09-09 09:27:45 -07:00
Junio C Hamano
5f0bdf50c2 safe_create_leading_directories(): make it about "leading" directories
We used to allow callers to pass "foo/bar/" to make sure both "foo" and
"foo/bar" exist and have good permissions, but this interface is too error
prone.  If a caller mistakenly passes a path with trailing slashes
(perhaps it forgot to verify the user input) even when it wants to later
mkdir "bar" itself, it will find that it cannot mkdir "bar".  If such a
caller does not bother to check the error for EEXIST, it may even
errorneously die().

Because we have no existing callers to use that obscure feature, this
patch removes it to avoid confusion.

Signed-off-by: Junio C Hamano <gitster@pobox.com>
2008-09-03 22:35:32 -07:00
Junio C Hamano
5a1e8707a6 Merge branch 'np/verify-pack'
* np/verify-pack:
  discard revindex data when pack list changes
2008-08-27 16:39:46 -07:00
Nicolas Pitre
4b480c6716 discard revindex data when pack list changes
This is needed to fix verify-pack -v with multiple pack arguments.

Also, in theory, revindex data (if any) must be discarded whenever
reprepare_packed_git() is called. In practice this is hard to trigger
though.

Signed-off-by: Nicolas Pitre <nico@cam.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2008-08-22 22:00:22 -07:00
Junio C Hamano
d8eec50468 Merge branch 'dp/hash-literally'
* dp/hash-literally:
  add --no-filters option to git hash-object
  add --path option to git hash-object
  use parse_options() in git hash-object
  correct usage help string for git-hash-object
  correct argument checking test for git hash-object
  teach index_fd to work with pipes
2008-08-19 21:43:25 -07:00
Steven Grimm
ddd63e64e4 Optimize sha1_object_info for loose objects, not concurrent repacks
When dealing with a repository with lots of loose objects, sha1_object_info
would rescan the packs directory every time an unpacked object was referenced
before finally giving up and looking for the loose object. This caused a lot
of extra unnecessary system calls during git pack-objects; the code was
rereading the entire pack directory once for each loose object file.

This patch looks for a loose object before falling back to rescanning the
pack directory, rather than the other way around.

Signed-off-by: Steven Grimm <koreth@midwinter.com>
Acked-by: Shawn O. Pearce <spearce@spearce.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2008-08-05 21:21:20 -07:00
Dmitry Potapov
43df4f86e0 teach index_fd to work with pipes
index_fd can now work with file descriptors that are not normal files
but any readable file. If the given file descriptor is a regular file
then mmap() is used; for other files, strbuf_read is used.

The path parameter, which has been used as hint for filters, can be
NULL now to indicate that the file should be hashed literally without
any filter.

The index_pipe function is removed as redundant.

Signed-off-by: Dmitry Potapov <dpotapov@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2008-08-03 13:14:35 -07:00
Nicolas Pitre
ac9391093f restore legacy behavior for read_sha1_file()
Since commit 8eca0b47ff, it is possible
for read_sha1_file() to return NULL even with existing objects when they
are corrupted.  Previously a corrupted object would have terminated the
program immediately, effectively making read_sha1_file() return NULL
only when specified object is not found.

Let's restore this behavior for all users of read_sha1_file() and
provide a separate function with the ability to not terminate when
bad objects are encountered.

Signed-off-by: Nicolas Pitre <nico@cam.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2008-07-14 23:35:32 -07:00
Junio C Hamano
948e7471e0 Merge branch 'sp/maint-pack-memuse'
* sp/maint-pack-memuse:
  Correct pack memory leak causing git gc to try to exceed ulimit

Conflicts:

	sha1_file.c
2008-07-09 14:46:46 -07:00
Shawn O. Pearce
eac12e2d4d Correct pack memory leak causing git gc to try to exceed ulimit
When recursing to unpack a delta base we must unuse_pack() so that
the pack window for the current object does not remain pinned in
memory while the delta base is itself being unpacked and materialized
for our use.

On a long delta chain of 50 objects we may need to access 6 different
windows from a very large (>3G) pack file in order to obtain all
of the delta base content.  If the process ulimit permits us to
map/allocate only 1.5G we must release windows during this recursion
to ensure we stay within the ulimit and transition memory from pack
cache to standard malloc, or other mmap needs.

Inserting an unuse_pack() call prior to the recursion allows us to
avoid pinning the current window, making it available for garbage
collection if memory runs low.

This has been broken since at least before 1.5.1-rc1, and very
likely earlier than that.  Its fixed now.  :)

Signed-off-by: Shawn O. Pearce <spearce@spearce.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2008-07-09 14:45:42 -07:00
Ramsay Jones
6e1c23442a Fix some warnings (on cygwin) to allow -Werror
When printing valuds of type uint32_t, we should use PRIu32, and should
not assume that it is unsigned int.  On 32-bit platforms, it could be
defined as unsigned long. The same caution applies to ntohl().

Signed-off-by: Ramsay Jones <ramsay@ramsay1.demon.co.uk>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2008-07-05 17:26:29 -07:00
Junio C Hamano
bb1ab2db08 Merge branch 'j6t/mingw'
* j6t/mingw: (38 commits)
  compat/pread.c: Add a forward declaration to fix a warning
  Windows: Fix ntohl() related warnings about printf formatting
  Windows: TMP and TEMP environment variables specify a temporary directory.
  Windows: Make 'git help -a' work.
  Windows: Work around an oddity when a pipe with no reader is written to.
  Windows: Make the pager work.
  When installing, be prepared that template_dir may be relative.
  Windows: Use a relative default template_dir and ETC_GITCONFIG
  Windows: Compute the fallback for exec_path from the program invocation.
  Turn builtin_exec_path into a function.
  Windows: Use a customized struct stat that also has the st_blocks member.
  Windows: Add a custom implementation for utime().
  Windows: Add a new lstat and fstat implementation based on Win32 API.
  Windows: Implement a custom spawnve().
  Windows: Implement wrappers for gethostbyname(), socket(), and connect().
  Windows: Work around incompatible sort and find.
  Windows: Implement asynchronous functions as threads.
  Windows: Disambiguate DOS style paths from SSH URLs.
  Windows: A rudimentary poll() emulation.
  Windows: Implement start_command().
  ...
2008-07-02 21:57:52 -07:00
Junio C Hamano
abf7e0df17 Merge branch 'lt/config-fsync'
* lt/config-fsync:
  Add config option to enable 'fsync()' of object files
  Split up default "i18n" and "branch" config parsing into helper routines
  Split up default "user" config parsing into helper routine
  Split up default "core" config parsing into helper routine
2008-06-25 13:19:49 -07:00
Jeff King
2beebd22f4 clone: create intermediate directories of destination repo
The shell version used to use "mkdir -p" to create the repo
path, but the C version just calls "mkdir". Let's replicate
the old behavior. We have to create the git and worktree
leading dirs separately; while most of the time, the
worktree dir contains the git dir (as .git), the user can
override this using GIT_WORK_TREE.

We can reuse safe_create_leading_directories, but we need to
make a copy of our const buffer to do so. Since
merge-recursive uses the same pattern, we can factor this
out into a global function. This has two other cleanup
advantages for merge-recursive:

  1. mkdir_p wasn't a very good name. "mkdir -p foo/bar" actually
     creates bar, but this function just creates the leading
     directories.

  2. mkdir_p took a mode argument, but it was completely
     ignored.

Acked-by: Daniel Barkalow <barkalow@iabervon.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2008-06-25 11:44:15 -07:00
Nicolas Pitre
99093238bb optimize verify-pack a bit
Using find_pack_entry_one() to get object offsets is rather suboptimal
when nth_packed_object_offset() can be used directly.

Signed-off-by: Nicolas Pitre <nico@cam.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2008-06-24 23:58:57 -07:00
Jeff King
8e21d63b02 clone: create intermediate directories of destination repo
The shell version used to use "mkdir -p" to create the repo
path, but the C version just calls "mkdir". Let's replicate
the old behavior. We have to create the git and worktree
leading dirs separately; while most of the time, the
worktree dir contains the git dir (as .git), the user can
override this using GIT_WORK_TREE.

We can reuse safe_create_leading_directories, but we need to
make a copy of our const buffer to do so. Since
merge-recursive uses the same pattern, we can factor this
out into a global function. This has two other cleanup
advantages for merge-recursive:

  1. mkdir_p wasn't a very good name. "mkdir -p foo/bar" actually
     creates bar, but this function just creates the leading
     directories.

  2. mkdir_p took a mode argument, but it was completely
     ignored.

Acked-by: Daniel Barkalow <barkalow@iabervon.org>

Signed-off-by: Junio C Hamano <gitster@pobox.com>
2008-06-24 23:23:21 -07:00
Nicolas Pitre
27d69a465d refactor pack structure allocation
New pack structures are currently allocated in 2 different places
and all members have to be initialized explicitly.  This is prone
to errors leading to segmentation faults as found by Teemu Likonen.

Let's have a common place where this structure is allocated, and have
all members explicitly initialized to zero.

Signed-off-by: Nicolas Pitre <nico@cam.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2008-06-24 17:03:44 -07:00
Nicolas Pitre
8eca0b47ff implement some resilience against pack corruptions
We should be able to fall back to loose objects or alternative packs when
a pack becomes corrupted.  This is especially true when an object exists
in one pack only as a delta but its base object is corrupted.  Currently
there is no way to retrieve the former object even if the later is
available in another pack or loose.

This patch allows for a delta to be resolved (with a performance cost)
using a base object from a source other than the pack where that delta
is located.  Same thing for non-delta objects: rather than failing
outright, a search is made in other packs or used loose when the
currently active pack has it but corrupted.

Of course git will become extremely noisy with error messages when that
happens.  However, if the operation succeeds nevertheless, a simple
'git repack -a -f -d' will "fix" the corrupted repository given that all
corrupted objects have a good duplicate somewhere in the object store,
possibly manually copied from another source.

Signed-off-by: Nicolas Pitre <nico@cam.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2008-06-23 21:29:33 -07:00
Patrick Higgins
6ff6af62ec Workaround for AIX mkstemp()
The AIX mkstemp will modify it's template parameter to an empty string if
the call fails. This caused a subsequent mkdir to fail.

Signed-off-by: Patrick Higgins <patrick.higgins@cexp.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2008-06-23 16:13:38 -07:00
Johannes Sixt
8385abfda5 Windows: Handle absolute paths in safe_create_leading_directories().
In this function we must be careful to handle drive-local paths else there
is a danger that it runs into an infinite loop.

Signed-off-by: Johannes Sixt <johannes.sixt@telecom.at>
2008-06-23 13:30:27 +02:00
Johannes Sixt
80ba074f41 Windows: Use the Windows style PATH separator ';'.
Signed-off-by: Johannes Sixt <johannes.sixt@telecom.at>
2008-06-22 11:32:45 +02:00
Linus Torvalds
aafe9fbaf4 Add config option to enable 'fsync()' of object files
As explained in the documentation[*] this is totally useless on
filesystems that do ordered/journalled data writes, but it can be a
useful safety feature on filesystems like HFS+ that only journal the
metadata, not the actual file contents.

It defaults to off, although we could presumably in theory some day
auto-enable it on a per-filesystem basis.

[*] Yes, I updated the docs for the thing.  Hell really _has_ frozen
    over, and the four horsemen are probably just beyond the horizon.
    EVERYBODY PANIC!

Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2008-06-18 16:50:35 -07:00
Junio C Hamano
79c6dca413 sha1_file.c: simplify parse_pack_index()
It was implemented as a thin wrapper around an otherwise unused
helper function parse_pack_index_file().  The code becomes simpler
and easier to read by consolidating the two.

Signed-off-by: Junio C Hamano <gitster@pobox.com>
2008-06-16 22:19:00 -07:00
Junio C Hamano
3bfaf01857 create_tempfile: make sure that leading directories can be accessible by peers
In a shared repository, we should make sure adjust_shared_perm() is called
after creating the initial fan-out directories under objects/ directory.

Earlier an logico called the function only when mkdir() failed; we should
do so when mkdir() succeeded.

Signed-off-by: Junio C Hamano <gitster@pobox.com>
2008-06-16 22:02:12 -07:00
Linus Torvalds
1421c5f274 write_loose_object: don't bother trying to read an old object
Before even calling this, all callers have done a "has_sha1_file(sha1)"
or "has_loose_object(sha1)" check, so there is no point in doing a
second check.

If something races with us on object creation, we handle that in the
final link() that moves it to the right place.

Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2008-06-16 21:46:47 -07:00
Linus Torvalds
c529d75a75 Simplify and rename find_sha1_file()
Now that we've made the loose SHA1 file reading more careful and
streamlined, we only use the old find_sha1_file() function for checking
whether a loose object file exists at all.

As such, the whole 'return stat information' part of it was just
pointless (nobody cares any more), and the naming of the function is not
really all that relevant either.

So simplify it to not do a 'stat()', but just an existence check (which
is what the callers want), and rename it to 'has_loose_object()' which
matches the use.

Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2008-06-14 14:39:22 -07:00
Linus Torvalds
44d1c19ee8 Make loose object file reading more careful
We used to do 'stat()+open()+mmap()+close()' to read the loose object
file data, which does work fine, but has a couple of problems:

 - it unnecessarily walks the filename twice (at 'stat()' time and then
   again to open it)

 - NFS generally has open-close consistency guarantees, which means that
   the initial 'stat()' was technically done outside of the normal
   consistency rules.

So change it to do 'open()+fstat()+mmap()+close()' instead, which avoids
both these issues.

Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2008-06-14 14:39:22 -07:00
Linus Torvalds
5723fe7e3c Avoid cross-directory renames and linking on object creation
Instead of creating new temporary objects in the top-level git object
directory, create them in the same directory they will finally end up in
anyway.  This avoids making the final atomic "rename to stable name"
operation be a cross-directory event, which makes it a lot easier for
various filesystems.

Several filesystems do things like change the inode number when moving
files across directories (or refuse to do it entirely).

In particular, it can also cause problems for NFS implementations that
change the filehandle of a file when it moves to a different directory,
like the old user-space NFS server did, and like the Linux knfsd still
does if you don't export your filesystems with 'no_subtree_check' or if
you export a filesystem that doesn't have stable inode numbers across
renames).

This change also obviously implies creating the object fan-out
subdirectory at tempfile creation time, rather than at the final
move_temp_to_file() time.  Which actually accounts for most of the size
of the patch.

Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2008-06-14 14:39:22 -07:00
Junio C Hamano
6483925999 sha1_file.c: dead code removal
write_sha1_from_fd() and write_sha1_to_fd() were dead code nobody called,
neither the latter's helper repack_object() was.

Signed-off-by: Junio C Hamano <gitster@pobox.com>
2008-06-13 23:00:51 -07:00
Linus Torvalds
e9039dd351 Consolidate SHA1 object file close
This consolidates the common operations for closing the new temporary file
that we have written, before we move it into place with the final name.

There's some common code there (make it read-only and check for errors on
close), but more importantly, this also gives a single place to add an
fsync_or_die() call if we want to add a safe mode.

This was triggered due to Denis Bueno apparently twice being able to
corrupt his git repository on OS X due to an unlucky combination of kernel
crashes and a not-very-robust filesystem.

Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2008-06-10 22:23:18 -07:00
Junio C Hamano
6eec46bdda fix sha1_pack_index_name()
An earlier commit 633f43e (Remove redundant code, eliminate one static
variable, 2008-05-24) had a thinko (perhaps an eyeno) that broke
sha1_pack_index_name() function.  One symptom of this was that the http
walker is now completely broken.

This should fix it.

Signed-off-by: Junio C Hamano <gitster@pobox.com>
2008-05-28 10:24:32 -07:00
Junio C Hamano
b84c343c88 Merge branch 'db/clone-in-c'
* db/clone-in-c:
  Add test for cloning with "--reference" repo being a subset of source repo
  Add a test for another combination of --reference
  Test that --reference actually suppresses fetching referenced objects
  clone: fall back to copying if hardlinking fails
  builtin-clone.c: Need to closedir() in copy_or_link_directory()
  builtin-clone: fix initial checkout
  Build in clone
  Provide API access to init_db()
  Add a function to set a non-default work tree
  Allow for having for_each_ref() list extra refs
  Have a constant extern refspec for "--tags"
  Add a library function to add an alternate to the alternates file
  Add a lockfile function to append to a file
  Mark the list of refs to fetch as const

Conflicts:

	cache.h
	t/t5700-clone-reference.sh
2008-05-25 13:41:37 -07:00
Heikki Orsila
633f43e1f7 Remove redundant code, eliminate one static variable
Signed-off-by: Heikki Orsila <heikki.orsila@iki.fi>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2008-05-24 22:05:06 -07:00
Nicolas Pitre
bbac73117e add a force_object_loose() function
This is meant to force the creation of a loose object even if it
already exists packed.  Needed for the next commit.

Signed-off-by: Nicolas Pitre <nico@cam.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2008-05-13 22:42:33 -07:00
Daniel Barkalow
bef70b22ba Add a library function to add an alternate to the alternates file
This is in the core so that, if the alternates file has already been
read, the addition can be parsed and put into effect for the current
process.

Signed-off-by: Daniel Barkalow <barkalow@iabervon.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2008-05-04 17:41:44 -07:00
Heikki Orsila
c697ad143b Cleanup xread() loops to use read_in_full()
Signed-off-by: Heikki Orsila <heikki.orsila@iki.fi>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2008-05-03 22:15:25 -07:00
Junio C Hamano
628522ec14 sha1-lookup: more memory efficient search in sorted list of SHA-1
Currently, when looking for a packed object from the pack idx, a
simple binary search is used.

A conventional binary search loop looks like this:

        unsigned lo, hi;
        do {
                unsigned mi = (lo + hi) / 2;
                int cmp = "entry pointed at by mi" minus "target";
                if (!cmp)
                        return mi; "mi is the wanted one"
                if (cmp > 0)
                        hi = mi; "mi is larger than target"
                else
                        lo = mi+1; "mi is smaller than target"
        } while (lo < hi);
	"did not find what we wanted"

The invariants are:

  - When entering the loop, 'lo' points at a slot that is never
    above the target (it could be at the target), 'hi' points at
    a slot that is guaranteed to be above the target (it can
    never be at the target).

  - We find a point 'mi' between 'lo' and 'hi' ('mi' could be
    the same as 'lo', but never can be as high as 'hi'), and
    check if 'mi' hits the target.  There are three cases:

     - if it is a hit, we have found what we are looking for;

     - if it is strictly higher than the target, we set it to
       'hi', and repeat the search.

     - if it is strictly lower than the target, we update 'lo'
       to one slot after it, because we allow 'lo' to be at the
       target and 'mi' is known to be below the target.

    If the loop exits, there is no matching entry.

When choosing 'mi', we do not have to take the "middle" but
anywhere in between 'lo' and 'hi', as long as lo <= mi < hi is
satisfied.  When we somehow know that the distance between the
target and 'lo' is much shorter than the target and 'hi', we
could pick 'mi' that is much closer to 'lo' than (hi+lo)/2,
which a conventional binary search would pick.

This patch takes advantage of the fact that the SHA-1 is a good
hash function, and as long as there are enough entries in the
table, we can expect uniform distribution.  An entry that begins
with for example "deadbeef..." is much likely to appear much
later than in the midway of a reasonably populated table.  In
fact, it can be expected to be near 87% (222/256) from the top
of the table.

This is a work-in-progress and has switches to allow easier
experiments and debugging.  Exporting GIT_USE_LOOKUP environment
variable enables this code.

On my admittedly memory starved machine, with a partial KDE
repository (3.0G pack with 95M idx):

    $ GIT_USE_LOOKUP=t git log -800 --stat HEAD >/dev/null
    3.93user 0.16system 0:04.09elapsed 100%CPU (0avgtext+0avgdata 0maxresident)k
    0inputs+0outputs (0major+55588minor)pagefaults 0swaps

Without the patch, the numbers are:

    $ git log -800 --stat HEAD >/dev/null
    4.00user 0.15system 0:04.17elapsed 99%CPU (0avgtext+0avgdata 0maxresident)k
    0inputs+0outputs (0major+60258minor)pagefaults 0swaps

In the same repository:

    $ GIT_USE_LOOKUP=t git log -2000 HEAD >/dev/null
    0.12user 0.00system 0:00.12elapsed 97%CPU (0avgtext+0avgdata 0maxresident)k
    0inputs+0outputs (0major+4241minor)pagefaults 0swaps

Without the patch, the numbers are:

    $ git log -2000 HEAD >/dev/null
    0.05user 0.01system 0:00.07elapsed 100%CPU (0avgtext+0avgdata 0maxresident)k
    0inputs+0outputs (0major+8506minor)pagefaults 0swaps

There isn't much time difference, but the number of minor faults
seems to show that we are touching much smaller number of pages,
which is expected.

Signed-off-by: Junio C Hamano <gitster@pobox.com>
2008-04-09 01:23:52 -07:00
Nicolas Pitre
70f5d5d31c fix unimplemented packed_object_info_detail() features
Since commit eb32d236df, there was a TODO
comment in packed_object_info_detail() about the SHA1 of base object to
OBJ_OFS_DELTA objects.  So here it is at last.

While at it, providing the actual storage size information as well is now
trivial.

Signed-off-by: Nicolas Pitre <nico@cam.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2008-03-01 01:44:46 -08:00
Junio C Hamano
c484166374 Merge branch 'jk/empty-tree'
* jk/empty-tree:
  add--interactive: handle initial commit better
  hard-code the empty tree object
2008-02-20 16:13:28 -08:00
Junio C Hamano
ee4f06c0a6 Merge branch 'mk/maint-parse-careful'
* mk/maint-parse-careful:
  peel_onion: handle NULL
  check return value from parse_commit() in various functions
  parse_commit: don't fail, if object is NULL
  revision.c: handle tag->tagged == NULL
  reachable.c::process_tree/blob: check for NULL
  process_tag: handle tag->tagged == NULL
  check results of parse_commit in merge_bases
  list-objects.c::process_tree/blob: check for NULL
  reachable.c::add_one_tree: handle NULL from lookup_tree
  mark_blob/tree_uninteresting: check for NULL
  get_sha1_oneline: check return value of parse_object
  read_object_with_reference: don't read beyond the buffer
2008-02-18 20:56:01 -08:00
Martin Koegler
50974ec994 read_object_with_reference: don't read beyond the buffer
Signed-off-by: Martin Koegler <mkoegler@auto.tuwien.ac.at>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2008-02-18 19:20:17 -08:00
Jeff King
346245a1bb hard-code the empty tree object
Now any commands may reference the empty tree object by its
sha1 (4b825dc642). This is
useful for showing some diffs, especially for initial
commits.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2008-02-13 13:44:17 -08:00
Steffen Prohaska
21e5ad50fc safecrlf: Add mechanism to warn about irreversible crlf conversions
CRLF conversion bears a slight chance of corrupting data.
autocrlf=true will convert CRLF to LF during commit and LF to
CRLF during checkout.  A file that contains a mixture of LF and
CRLF before the commit cannot be recreated by git.  For text
files this is the right thing to do: it corrects line endings
such that we have only LF line endings in the repository.
But for binary files that are accidentally classified as text the
conversion can corrupt data.

If you recognize such corruption early you can easily fix it by
setting the conversion type explicitly in .gitattributes.  Right
after committing you still have the original file in your work
tree and this file is not yet corrupted.  You can explicitly tell
git that this file is binary and git will handle the file
appropriately.

Unfortunately, the desired effect of cleaning up text files with
mixed line endings and the undesired effect of corrupting binary
files cannot be distinguished.  In both cases CRLFs are removed
in an irreversible way.  For text files this is the right thing
to do because CRLFs are line endings, while for binary files
converting CRLFs corrupts data.

This patch adds a mechanism that can either warn the user about
an irreversible conversion or can even refuse to convert.  The
mechanism is controlled by the variable core.safecrlf, with the
following values:

 - false: disable safecrlf mechanism
 - warn: warn about irreversible conversions
 - true: refuse irreversible conversions

The default is to warn.  Users are only affected by this default
if core.autocrlf is set.  But the current default of git is to
leave core.autocrlf unset, so users will not see warnings unless
they deliberately chose to activate the autocrlf mechanism.

The safecrlf mechanism's details depend on the git command.  The
general principles when safecrlf is active (not false) are:

 - we warn/error out if files in the work tree can modified in an
   irreversible way without giving the user a chance to backup the
   original file.

 - for read-only operations that do not modify files in the work tree
   we do not not print annoying warnings.

There are exceptions.  Even though...

 - "git add" itself does not touch the files in the work tree, the
   next checkout would, so the safety triggers;

 - "git apply" to update a text file with a patch does touch the files
   in the work tree, but the operation is about text files and CRLF
   conversion is about fixing the line ending inconsistencies, so the
   safety does not trigger;

 - "git diff" itself does not touch the files in the work tree, it is
   often run to inspect the changes you intend to next "git add".  To
   catch potential problems early, safety triggers.

The concept of a safety check was originally proposed in a similar
way by Linus Torvalds.  Thanks to Dimitry Potapov for insisting
on getting the naked LF/autocrlf=true case right.

Signed-off-by: Steffen Prohaska <prohaska@zib.de>
2008-02-06 13:07:28 -08:00
Shawn O. Pearce
c9ced051c3 Fix random fast-import errors when compiled with NO_MMAP
fast-import was relying on the fact that on most systems mmap() and
write() are synchronized by the filesystem's buffer cache.  We were
relying on the ability to mmap() 20 bytes beyond the current end
of the file, then later fill in those bytes with a future write()
call, then read them through the previously obtained mmap() address.

This isn't always true with some implementations of NFS, but it is
especially not true with our NO_MMAP=YesPlease build time option used
on some platforms.  If fast-import was built with NO_MMAP=YesPlease
we used the malloc()+pread() emulation and the subsequent write()
call does not update the trailing 20 bytes of a previously obtained
"mmap()" (aka malloc'd) address.

Under NO_MMAP that behavior causes unpack_entry() in sha1_file.c to
be unable to read an object header (or data) that has been unlucky
enough to be written to the packfile at a location such that it
is in the trailing 20 bytes of a window previously opened on that
same packfile.

This bug has gone unnoticed for a very long time as it is highly data
dependent.  Not only does the object have to be placed at the right
position, but it also needs to be positioned behind some other object
that has been accessed due to a branch cache invalidation.  In other
words the stars had to align just right, and if you did run into
this bug you probably should also have purchased a lottery ticket.

Fortunately the workaround is a lot easier than the bug explanation.

Before we allow unpack_entry() to read data from a pack window
that has also (possibly) been modified through write() we force
all existing windows on that packfile to be closed.  By closing
the windows we ensure that any new access via the emulated mmap()
will reread the packfile, updating to the current file content.

This comes at a slight performance degredation as we cannot reuse
previously cached windows when we update the packfile.  But it
is a fairly minor difference as the window closes happen at only
two points:

 - When the packfile is finalized and its .idx is generated:

   At this stage we are getting ready to update the refs and any
   data access into the packfile is going to be random, and is
   going after only the branch tips (to ensure they are valid).
   Our existing windows (if any) are not likely to be positioned
   at useful locations to access those final tip commits so we
   probably were closing them before anyway.

 - When the branch cache missed and we need to reload:

   At this point fast-import is getting change commands for the next
   commit and it needs to go re-read a tree object it previously
   had written out to the packfile.  What windows we had (if any)
   are not likely to cover the tree in question so we probably were
   closing them before anyway.

We do try to avoid unnecessarily closing windows in the second case
by checking to see if the packfile size has increased since the
last time we called unpack_entry() on that packfile.  If the size
has not changed then we have not written additional data, and any
existing window is still vaild.  This nicely handles the cases where
fast-import is going through a branch cache reload and needs to read
many trees at once.  During such an event we are not likely to be
updating the packfile so we do not cycle the windows between reads.

With this change in place t9301-fast-export.sh (which was broken
by c3b0dec509) finally works again.

Signed-off-by: Shawn O. Pearce <spearce@spearce.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2008-01-17 22:39:20 -08:00
Jim Meyering
790296fd88 Fix grammar nits in documentation and in code comments.
Signed-off-by: Jim Meyering <meyering@redhat.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2008-01-03 09:15:17 -08:00
Steffen Prohaska
9e42d6a1c5 sha1_file.c: Fix size_t related printf format warnings
The old way of fixing warnings did not succeed on MinGW.  MinGW
does not support C99 printf format strings for size_t [1].  But
gcc on MinGW issues warnings if C99 printf format is not used.
Hence, the old stragegy to avoid warnings fails.

[1] http://www.mingw.org/MinGWiki/index.php/C99

This commits passes arguments of type size_t through a tiny
helper functions that casts to the type expected by the format
string.

Signed-off-by: Steffen Prohaska <prohaska@zib.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2007-11-28 16:03:38 -08:00
Johannes Sixt
85dadc3894 Use is_absolute_path() in sha1_file.c.
There are some places that test for an absolute path. Use the helper
function to ease porting.

Signed-off-by: Johannes Sixt <johannes.sixt@telecom.at>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2007-11-14 15:18:39 -08:00
Junio C Hamano
e2b7eaf0ca Merge branch 'maint'
* maint:
  RelNotes-1.5.3.5: describe recent fixes
  merge-recursive.c: mrtree in merge() is not used before set
  sha1_file.c: avoid gcc signed overflow warnings
  Fix a small memory leak in builtin-add
  honor the http.sslVerify option in shell scripts
2007-10-29 12:53:54 -07:00
Junio C Hamano
7109c889f1 sha1_file.c: avoid gcc signed overflow warnings
With the recent gcc, we get:

sha1_file.c: In check_packed_git_:
sha1_file.c:527: warning: assuming signed overflow does not
occur when assuming that (X + c) < X is always false
sha1_file.c:527: warning: assuming signed overflow does not
occur when assuming that (X + c) < X is always false

for a piece of code that tries to make sure that off_t is large
enough to hold more than 2^32 offset.  The test tried to make
sure these do not wrap-around:

    /* make sure we can deal with large pack offsets */
    off_t x = 0x7fffffffUL, y = 0xffffffffUL;
    if (x > (x + 1) || y > (y + 1)) {

but gcc assumes it can do whatever optimization it wants for a
signed overflow (undefined behaviour) and warns about this
construct.

Follow Linus's suggestion to check sizeof(off_t) instead to work
around the problem.

Signed-off-by: Junio C Hamano <gitster@pobox.com>
2007-10-29 11:56:57 -07:00
Junio C Hamano
66d4035e10 Merge branch 'ph/strbuf'
* ph/strbuf: (44 commits)
  Make read_patch_file work on a strbuf.
  strbuf_read_file enhancement, and use it.
  strbuf change: be sure ->buf is never ever NULL.
  double free in builtin-update-index.c
  Clean up stripspace a bit, use strbuf even more.
  Add strbuf_read_file().
  rerere: Fix use of an empty strbuf.buf
  Small cache_tree_write refactor.
  Make builtin-rerere use of strbuf nicer and more efficient.
  Add strbuf_cmp.
  strbuf_setlen(): do not barf on setting length of an empty buffer to 0
  sq_quote_argv and add_to_string rework with strbuf's.
  Full rework of quote_c_style and write_name_quoted.
  Rework unquote_c_style to work on a strbuf.
  strbuf API additions and enhancements.
  nfv?asprintf are broken without va_copy, workaround them.
  Fix the expansion pattern of the pseudo-static path buffer.
  builtin-for-each-ref.c::copy_name() - do not overstep the buffer.
  builtin-apply.c: fix a tiny leak introduced during xmemdupz() conversion.
  Use xmemdupz() in many places.
  ...
2007-10-03 03:06:02 -07:00
Pierre Habouzit
b315c5c081 strbuf change: be sure ->buf is never ever NULL.
For that purpose, the ->buf is always initialized with a char * buf living
in the strbuf module. It is made a char * so that we can sloppily accept
things that perform: sb->buf[0] = '\0', and because you can't pass "" as an
initializer for ->buf without making gcc unhappy for very good reasons.

strbuf_init/_detach/_grow have been fixed to trust ->alloc and not ->buf
anymore.

as a consequence strbuf_detach is _mandatory_ to detach a buffer, copying
->buf isn't an option anymore, if ->buf is going to escape from the scope,
and eventually be free'd.

API changes:
  * strbuf_setlen now always works, so just make strbuf_reset a convenience
    macro.
  * strbuf_detatch takes a size_t* optional argument (meaning it can be
    NULL) to copy the buffer's len, as it was needed for this refactor to
    make the code more readable, and working like the callers.

Signed-off-by: Pierre Habouzit <madcoder@debian.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2007-09-29 02:13:33 -07:00
Pierre Habouzit
182af8343c Use xmemdupz() in many places.
Signed-off-by: Pierre Habouzit <madcoder@debian.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2007-09-18 17:42:17 -07:00
Junio C Hamano
000dfd3f6e Export matches_pack_name() and fix its return value
The function sounds boolean; make it behave as one, not "0 for
success, non-zero for failure".

Signed-off-by: Junio C Hamano <gitster@pobox.com>
2007-09-17 12:25:26 -07:00
Pierre Habouzit
ba3ed09728 Now that cache.h needs strbuf.h, remove useless includes.
Signed-off-by: Pierre Habouzit <madcoder@debian.org>
Acked-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2007-09-16 17:30:03 -07:00
Pierre Habouzit
5ecd293d14 Rewrite convert_to_{git,working_tree} to use strbuf's.
* Now, those functions take an "out" strbuf argument, where they store their
  result if any. In that case, it also returns 1, else it returns 0.
* those functions support "in place" editing, in the sense that it's OK to
  call them this way:
    convert_to_git(path, sb->buf, sb->len, sb);
  When doable, conversions are done in place for real, else the strbuf
  content is just replaced with the new one, transparentely for the caller.

If you want to create a new filter working this way, being the accumulation
of filter1, filter2, ... filtern, then your meta_filter would be:

    int meta_filter(..., const char *src, size_t len, struct strbuf *sb)
    {
        int ret = 0;
        ret |= filter1(...., src, len, sb);
        if (ret) {
            src = sb->buf;
            len = sb->len;
        }
        ret |= filter2(...., src, len, sb);
        if (ret) {
            src = sb->buf;
            len = sb->len;
        }
        ....
        return ret | filtern(..., src, len, sb);
    }

That's why subfilters the convert_to_* functions called were also rewritten
to work this way.

Signed-off-by: Pierre Habouzit <madcoder@debian.org>
Acked-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2007-09-16 17:30:03 -07:00
Pierre Habouzit
fd17f5b5f7 Replace all read_fd use with strbuf_read, and get rid of it.
This brings builtin-stripspace, builtin-tag and mktag to use strbufs.

Signed-off-by: Pierre Habouzit <madcoder@debian.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2007-09-10 12:50:58 -07:00
Shawn O. Pearce
9064d87b06 Don't segfault if we failed to inflate a packed delta
Under some types of packfile corruption the zlib stream holding the
data for a delta within a packfile may fail to inflate, due to say
a CRC failure within the compressed data itself.  When this occurs
the unpack_compressed_entry function will return NULL as a signal to
the caller that the data is not available.  Unfortunately we then
tried to use that NULL as though it referenced a memory location
where a delta was stored and tried to apply it to the delta base.
Loading a byte from the NULL address typically causes a SIGSEGV.

cate on #git noticed this failure in `git fsck --full` where the
call to verify_pack() first noticed that the packfile was corrupt
by finding that the packfile's SHA-1 did not match the raw data of
the file.  After finding this fsck went ahead and tried to verify
every object within the packfile, even though the packfile was
already known to be bad.  If we are going to shovel bad data at
the delta unpacking code, we better handle it correctly.

Signed-off-by: Shawn O. Pearce <spearce@spearce.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2007-08-25 08:33:47 -07:00
Luiz Fernando N. Capitulino
eef427a09c Avoid ambiguous error message if pack.idx header is wrong
Print the index version when an error occurs so the user
knows what type of header (and size) we thought the index
should have had.

Signed-off-by: Luiz Fernando N. Capitulino <lcapitulino@mandriva.com.br>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2007-08-14 22:20:13 -07:00
Carlos Rica
c4fba0a358 Rename read_pipe() with read_fd() and make its buffer nul-terminated.
The new name is closer to the purpose of the function.

A NUL-terminated buffer makes things easier when callers need that.
Since the function returns only the memory written with data,
almost always allocating more space than needed because final
size is unknown, an extra NUL terminating the buffer is harmless.
It is not included in the returned size, so the function
remains working as before.

Also, now the function allows the buffer passed to be NULL at first,
and alloc_nr is now used for growing the buffer, instead size=*2.

Signed-off-by: Carlos Rica <jasampler@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2007-07-18 17:30:03 -07:00
Junio C Hamano
e2b1accc59 Merge branch 'maint'
* maint:
  Document -<n> for git-format-patch
  glossary: add 'reflog'
  diff --no-index: fix --name-status with added files
  Don't smash stack when $GIT_ALTERNATE_OBJECT_DIRECTORIES is too long
2007-07-03 22:56:59 -07:00
Jim Meyering
9cb18f56fd Don't smash stack when $GIT_ALTERNATE_OBJECT_DIRECTORIES is too long
There is no restriction on the length of the name returned by
get_object_directory, other than the fact that it must be a stat'able
git object directory.  That means its name may have length up to
PATH_MAX-1 (i.e., often 4095) not counting the trailing NUL.

Combine that with the assumption that the concatenation of that name and
suffixes like "/info/alternates" and "/pack/---long-name---.idx" will fit
in a buffer of length PATH_MAX, and you see the problem.  Here's a fix:

    sha1_file.c (prepare_packed_git_one): Lengthen "path" buffer
    so we are guaranteed to be able to append "/pack/" without checking.
    Skip any directory entry that is too long to be appended.
    (read_info_alternates): Protect against a similar buffer overrun.

Before this change, using the following admittedly contrived environment
setting would cause many git commands to clobber their stack and segfault
on a system with PATH_MAX == 4096:

  t=$(perl -e '$s=".git/objects";$n=(4096-6-length($s))/2;print "./"x$n . $s')
  export GIT_ALTERNATE_OBJECT_DIRECTORIES=$t
  touch g
  ./git-update-index --add g

If you run the above commands, you'll soon notice that many
git commands now segfault, so you'll want to do this:

  unset GIT_ALTERNATE_OBJECT_DIRECTORIES

Signed-off-by: Jim Meyering <jim@meyering.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2007-07-03 12:25:29 -07:00
Junio C Hamano
68fb465049 Merge branch 'maint'
* maint:
  config: Change output of --get-regexp for valueless keys
  config: Complete documentation of --get-regexp
  cleanup merge-base test script
  Fix zero-object version-2 packs
  Ignore submodule commits when fetching over dumb protocols
2007-06-26 18:45:29 -07:00
Linus Torvalds
1164f1e48d Fix zero-object version-2 packs
A pack-file can get created without any objects in it (to transfer "no
data" - which can happen if you use a reference git repo, for example,
or just otherwise just end up transferring only branch head information
and already have all the objects themselves).

And while we probably should never create an index for such a pack, if we
do (and we do), the index file size sanity checking was incorrect.

This fixes it.

Reported-and-tested-by: Jocke Tjernlund <tjernlund@tjernlund.se>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2007-06-26 18:02:15 -07:00
Junio C Hamano
4175e9e3a8 More static
There still are quite a few symbols that ought to be static.

Signed-off-by: Junio C Hamano <gitster@pobox.com>
2007-06-13 02:02:10 -07:00
Junio C Hamano
b79d18c92d -Wold-style-definition fix
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2007-06-13 02:02:10 -07:00
Junio C Hamano
a6080a0a44 War on whitespace
This uses "git-apply --whitespace=strip" to fix whitespace errors that have
crept in to our source files over time.  There are a few files that need
to have trailing whitespaces (most notably, test vectors).  The results
still passes the test, and build result in Documentation/ area is unchanged.

Signed-off-by: Junio C Hamano <gitster@pobox.com>
2007-06-07 00:04:01 -07:00
Junio C Hamano
17c2929aa2 Merge branch 'sp/pack'
* sp/pack:
  Style nit - don't put space after function names
  Ensure the pack index is opened before access
  Simplify index access condition in count-objects, pack-redundant
  Test for recent rev-parse $abbrev_sha1 regression
  rev-parse: Identify short sha1 sums correctly.
  Attempt to delay prepare_alt_odb during get_sha1
  Micro-optimize prepare_alt_odb
  Lazily open pack index files on demand
2007-06-02 12:18:51 -07:00
Junio C Hamano
bd724be4be Merge branch 'maint'
* maint:
  git-config: Improve documentation of git-config file handling
  git-config: Various small fixes to asciidoc documentation
  decode_85(): fix missing return.
  fix signed range problems with hex conversions
2007-05-31 00:15:14 -07:00
Junio C Hamano
8e29f903eb Merge branch 'maint-1.5.1' into maint
* maint-1.5.1:
  git-config: Improve documentation of git-config file handling
  git-config: Various small fixes to asciidoc documentation
  decode_85(): fix missing return.
  fix signed range problems with hex conversions
2007-05-31 00:09:26 -07:00
Nicolas Pitre
f7c22cc68c always start looking up objects in the last used pack first
Jon Smirl said:

| Once an object reference hits a pack file it is very likely that
| following references will hit the same pack file. So first place to
| look for an object is the same place the previous object was found.

This is indeed a good heuristic so here it is.  The search always start
with the pack where the last object lookup succeeded.  If the wanted
object is not available there then the search continues with the normal
pack ordering.

To test this I split the Linux repository into 66 packs and performed a
"time git-rev-list --objects --all > /dev/null".  Best results are as
follows:

	Pack Sort			w/o this patch	w/ this patch
	-------------------------------------------------------------
	recent objects last		26.4s		20.9s
	recent objects first		24.9s		18.4s

This shows that the pack order based on object age has some influence,
but that the last-used-pack heuristic is even more significant in
reducing object lookup.

Signed-off-by: Nicolas Pitre <nico@cam.org> --- Note: the
--max-pack-size to git-repack currently produces packs with old objects
after those containing recent objects.  The pack sort based on
filesystem timestamp is therefore backward for those.  This needs to be
fixed of course, but at least it made me think about this variable for
the test.
Signed-off-by: Junio C Hamano <junkio@cox.net>
2007-05-30 23:35:07 -07:00
Linus Torvalds
192a6be2a7 fix signed range problems with hex conversions
Make hexval_table[] "const".  Also make sure that the accessor
function hexval() does not access the table with out-of-range
values by declaring its parameter "unsigned char", instead of
"unsigned int".

With this, gcc can just generate:

	movzbl  (%rdi), %eax
	movsbl  hexval_table(%rax),%edx
	movzbl  1(%rdi), %eax
	movsbl  hexval_table(%rax),%eax
	sall    $4, %edx
	orl     %eax, %edx

for the code to generate a byte from two hex characters.

Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Junio C Hamano <junkio@cox.net>
2007-05-30 15:01:37 -07:00
Shawn O. Pearce
bc8e478a28 Style nit - don't put space after function names
Our style is to not put a space after a function name.  I did here,
and Junio applied the patch with the incorrect formatting.  So I'm
cleaning up after myself since I noticed it upon review.

Signed-off-by: Shawn O. Pearce <spearce@spearce.org>
Signed-off-by: Junio C Hamano <junkio@cox.net>
2007-05-29 23:31:19 -07:00
Shawn O. Pearce
7dc24aa5a6 Micro-optimize prepare_alt_odb
Calling getenv() is not that expensive, but its also not free,
and its certainly not cheaper than testing to see if alt_odb_tail
is not null.

Because we are calling prepare_alt_odb() from within find_sha1_file
every time we cannot find an object file locally we want to skip out
of prepare_alt_odb() as early as possible once we have initialized
our alternate list.

Signed-off-by: Shawn O. Pearce <spearce@spearce.org>
Signed-off-by: Junio C Hamano <junkio@cox.net>
2007-05-26 20:28:08 -07:00
Shawn O. Pearce
d079837eee Lazily open pack index files on demand
In some repository configurations the user may have many packfiles,
but all of the recent commits/trees/tags/blobs are likely to
be in the most recent packfile (the one with the newest mtime).
It is therefore common to be able to complete an entire operation
by accessing only one packfile, even if there are 25 packfiles
available to the repository.

Rather than opening and mmaping the corresponding .idx file for
every pack found, we now only open and map the .idx when we suspect
there might be an object of interest in there.

Of course we cannot known in advance which packfile contains an
object, so we still need to scan the entire packed_git list to
locate anything.  But odds are users want to access objects in the
most recently created packfiles first, and that may be all they
ever need for the current operation.

Junio observed in b867092f that placing recent packfiles before
older ones can slightly improve access times for recent objects,
without degrading it for historical object access.

This change improves upon Junio's observations by trying even harder
to avoid the .idx files that we won't need.

Signed-off-by: Shawn O. Pearce <spearce@spearce.org>
Signed-off-by: Junio C Hamano <junkio@cox.net>
2007-05-26 20:28:08 -07:00
Junio C Hamano
cc93020f52 Merge branch 'np/pack'
* np/pack:
  deprecate the new loose object header format
  make "repack -f" imply "pack-objects --no-reuse-object"
  allow for undeltified objects not to be reused
2007-05-20 02:18:43 -07:00
Johan Herland
8a912bcb25 Ensure return value from xread() is always stored into an ssize_t
This patch fixes all calls to xread() where the return value is not
stored into an ssize_t. The patch should not have any effect whatsoever,
other than putting better/more appropriate type names on variables.

Signed-off-by: Johan Herland <johan@herland.net>
Signed-off-by: Junio C Hamano <junkio@cox.net>
2007-05-15 21:16:03 -07:00
Nicolas Pitre
726f852b0e deprecate the new loose object header format
Now that we encourage and actively preserve objects in a packed form
more agressively than we did at the time the new loose object format and
core.legacyheaders were introduced, that extra loose object format
doesn't appear to be worth it anymore.

Because the packing of loose objects has to go through the delta match
loop anyway, and since most of them should end up being deltified in
most cases, there is really little advantage to have this parallel loose
object format as the CPU savings it might provide is rather lost in the
noise in the end.

This patch gets rid of core.legacyheaders, preserve the legacy format as
the only writable loose object format and deprecate the other one to
keep things simpler.

Signed-off-by: Nicolas Pitre <nico@cam.org>
Signed-off-by: Junio C Hamano <junkio@cox.net>
2007-05-10 15:22:33 -07:00
Junio C Hamano
6169a89c4f Merge branch 'maint'
* maint:
  Start preparing for 1.5.1.3
  Sanitize @to recipients.
  git-svn: Ignore usernames in URLs in find_by_url
  Document --dry-run and envelope-sender for git-send-email.
  Allow users to optionally specify their envelope sender.
  Ensure clean addresses are always used with Net::SMTP
  Validate @recipients before using it for sendmail and Net::SMTP.
  Perform correct quoting of recipient names.
  Change the scope of the $cc variable as it is not needed outside of send_message.
  Debugging cleanup improvements
  Prefix Dry- to the message status to denote dry-runs.
  Document --dry-run parameter to send-email.
  git-svn: Don't rely on $_ after making a function call
  Fix handle leak in write_tree
  Actually handle some-low memory conditions

Conflicts:

	RelNotes
	git-send-email.perl
2007-04-25 23:31:45 -07:00
Shawn O. Pearce
d1efefa46f Actually handle some-low memory conditions
Tim Ansell discovered his Debian server didn't permit git-daemon to
use as much memory as it needed to handle cloning a project with
a 128 MiB packfile.  Filtering the strace provided by Tim of the
rev-list child showed this gem of a sequence:

  open("./objects/pack/pack-*.pack", O_RDONLY|O_LARGEFILE <unfinished ...>
  <... open resumed> )              = 5

OK, so the packfile is fd 5...

  mmap2(NULL, 33554432, PROT_READ, MAP_PRIVATE, 5, 0 <unfinished ...>
   <... mmap2 resumed> )             = 0xb5e2d000

and we mapped one 32 MiB window from it at position 0...

   mmap2(NULL, 31020635, PROT_READ, MAP_PRIVATE, 5, 0x6000 <unfinished ...>
   <... mmap2 resumed> )             = -1 ENOMEM (Cannot allocate memory)

And we asked for another window further into the file.  But got
denied.  In Tim's case this was due to a resource limit on the
git-daemon process, and its children.

Now where are we in the code?  We're down inside use_pack(),
after we have called unuse_one_window() enough times to make sure
we stay within our allowed maximum window size.  However since we
didn't unmap the prior window at 0xb5e2d000 we aren't exceeding
the current limit (which probably was just the defaults).

But we're actually down inside xmmap()...

So we release the window we do have (by calling release_pack_memory),
assuming there is some memory pressure...

   munmap(0xb5e2d000, 33554432 <unfinished ...>
   <... munmap resumed> )            = 0
   close(5 <unfinished ...>
   <... close resumed> )             = 0

And that was the last window in this packfile.  So we closed it.
Way to go us.  Our xmmap did not expect release_pack_memory to
close the fd its about to map...

   mmap2(NULL, 31020635, PROT_READ, MAP_PRIVATE, 5, 0x6000 <unfinished ...>
   <... mmap2 resumed> )             = -1 EBADF (Bad file descriptor)

And so the Linux kernel happily tells us f' off.

   write(2, "fatal: ", 7 <unfinished ...>
   <... write resumed> )             = 7
   write(2, "Out of memory? mmap failed: Bad "..., 47 <unfinished ...>
   <... write resumed> )             = 47

And we report the bad file descriptor error, and not the ENOMEM,
and die, claiming we are out of memory.  But actually that mmap
should have succeeded, as we had enough memory for that window,
seeing as how we released the prior one.

Originally when I developed the sliding window mmap feature I had
this exact same bug in fast-import, and I dealt with it by handing
in the struct packed_git* we want to open the new window for, as the
caller wasn't prepared to reopen the packfile if unuse_one_window
closed it.  The same is true here from xmmap, but the caller doesn't
have the struct packed_git* handy.  So I'm using the file descriptor
instead to perform the same test.

Signed-off-by: Shawn O. Pearce <spearce@spearce.org>
Signed-off-by: Junio C Hamano <junkio@cox.net>
2007-04-25 14:22:24 -07:00
Junio C Hamano
a2d7c6c620 Merge branch 'jc/attr'
* 'jc/attr': (28 commits)
  lockfile: record the primary process.
  convert.c: restructure the attribute checking part.
  Fix bogus linked-list management for user defined merge drivers.
  Simplify calling of CR/LF conversion routines
  Document gitattributes(5)
  Update 'crlf' attribute semantics.
  Documentation: support manual section (5) - file formats.
  Simplify code to find recursive merge driver.
  Counto-fix in merge-recursive
  Fix funny types used in attribute value representation
  Allow low-level driver to specify different behaviour during internal merge.
  Custom low-level merge driver: change the configuration scheme.
  Allow the default low-level merge driver to be configured.
  Custom low-level merge driver support.
  Add a demonstration/test of customized merge.
  Allow specifying specialized merge-backend per path.
  merge-recursive: separate out xdl_merge() interface.
  Allow more than true/false to attributes.
  Document git-check-attr
  Change attribute negation marker from '!' to '-'.
  ...
2007-04-21 17:38:00 -07:00
Junio C Hamano
afb5b6a24b Merge branch 'lt/gitlink'
* lt/gitlink:
  Tests for core subproject support
  Expose subprojects as special files to "git diff" machinery
  Fix some "git ls-files -o" fallout from gitlinks
  Teach "git-read-tree -u" to check out submodules as a directory
  Teach git list-objects logic to not follow gitlinks
  Fix gitlink index entry filesystem matching
  Teach "git-read-tree -u" to check out submodules as a directory
  Teach git list-objects logic not to follow gitlinks
  Don't show gitlink directories when we want "other" files
  Teach git-update-index about gitlinks
  Teach directory traversal about subprojects
  Fix thinko in subproject entry sorting
  Teach core object handling functions about gitlinks
  Teach "fsck" not to follow subproject links
  Add "S_IFDIRLNK" file mode infrastructure for git links
  Add 'resolve_gitlink_ref()' helper function
  Avoid overflowing name buffer in deep directory structures
  diff-lib: use ce_mode_from_stat() rather than messing with modes manually
2007-04-21 17:21:10 -07:00
Alex Riesen
ac78e54804 Simplify calling of CR/LF conversion routines
Signed-off-by: Alex Riesen <raa.lkml@gmail.com>
Signed-off-by: Junio C Hamano <junkio@cox.net>
2007-04-20 23:24:34 -07:00
Nicolas Pitre
54dab52ae8 add get_size_from_delta()
... which consists of existing code split out of packed_delta_info()
for other callers to use it as well.

Signed-off-by: Nicolas Pitre <nico@cam.org>
Signed-off-by: Junio C Hamano <junkio@cox.net>
2007-04-16 17:43:31 -07:00
Linus Torvalds
f35a6d3bce Teach core object handling functions about gitlinks
This teaches the really fundamental core SHA1 object handling routines
about gitlinks.  We can compare trees with gitlinks in them (although we
can not actually generate patches for them yet - just raw git diffs),
and they show up as commits in "git ls-tree".

We also know to compare gitlinks as if they were directories (ie the
normal "sort as trees" rules apply).

[jc: amended a cut&paste error]

Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Junio C Hamano <junkio@cox.net>
2007-04-10 13:50:43 -07:00
Nicolas Pitre
74e34e1fca sha1_file.c: learn about index version 2
With this patch, packs larger than 4GB are usable, even on a 32-bit machine
(at least on Linux).  If off_t is not large enough to deal with a large
pack then die() is called instead of attempting to use the pack and
producing garbage.

This was tested with a 8GB pack specially created for the occasion on
a 32-bit machine.

Signed-off-by: Nicolas Pitre <nico@cam.org>
Signed-off-by: Junio C Hamano <junkio@cox.net>
2007-04-10 12:48:14 -07:00
Nicolas Pitre
8723f21626 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>
2007-04-10 12:48:14 -07:00
Nicolas Pitre
57059091fa get rid of num_packed_objects()
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>
2007-04-10 12:48:14 -07:00
Nicolas Pitre
d72308e01c 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>
2007-04-05 14:59:47 -07:00
Junio C Hamano
e82973cfb0 sha1_file.c (write_sha1_file): Detect close failure
This is in the same spirit as earlier fix to write_sha1_from_fd().

Signed-off-by: Junio C Hamano <junkio@cox.net>
2007-03-27 12:56:01 -07:00
Jim Meyering
0d315468f3 sha1_file.c (write_sha1_from_fd): Detect close failure.
I stumbled across this in the context of the fchmod 0444 patch.
At first, I was going to unlink and call error like the two subsequent
tests do, but a failed write (above) provokes a "die", so I made
this do the same.  This is testing for a write failure, after all.

Signed-off-by: Jim Meyering <jim@meyering.net>
Signed-off-by: Junio C Hamano <junkio@cox.net>
2007-03-27 12:43:49 -07:00
Nicolas Pitre
b5b8d8141a write_sha1_from_fd() should make new objects read-only
... like it is done everywhere else.

Signed-off-by: Nicolas Pitre <nico@cam.org>
Signed-off-by: Junio C Hamano <junkio@cox.net>
2007-03-24 22:32:41 -07:00
Nicolas Pitre
0e55181f29 make it more obvious that temporary files are temporary files
When some operations are interrupted (or "die()'d" or crashed) then the
partial object/pack/index file may remain around.  Make it more obvious
in their name that those files are temporary stuff and can be cleaned up
if no operation is in progress.

Signed-off-by: Nicolas Pitre <nico@cam.org>
Signed-off-by: Junio C Hamano <junkio@cox.net>
2007-03-24 22:32:39 -07:00
Linus Torvalds
ac54c277f0 Be more careful about zlib return values
When creating a new object, we use "deflate(stream, Z_FINISH)" in a loop
until it no longer returns Z_OK, and then we do "deflateEnd()" to finish
up business.

That should all work, but the fact is, it's not how you're _supposed_ to
use the zlib return values properly:

 - deflate() should never return Z_OK in the first place, except if we
   need to increase the output buffer size (which we're not doing, and
   should never need to do, since we pre-allocated a buffer that is
   supposed to be able to hold the output in full). So the "while()" loop
   was incorrect: Z_OK doesn't actually mean "ok, continue", it means "ok,
   allocate more memory for me and continue"!

 - if we got an error return, we would consider it to be end-of-stream,
   but it could be some internal zlib error.  In short, we should check
   for Z_STREAM_END explicitly, since that's the only valid return value
   anyway for the Z_FINISH case.

 - we never checked deflateEnd() return codes at all.

Now, admittedly, none of these issues should ever happen, unless there is
some internal bug in zlib. So this patch should make zero difference, but
it seems to be the right thing to do.

We should probablybe anal and check the return value of "deflateInit()"
too!

Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Junio C Hamano <junkio@cox.net>
2007-03-20 22:17:32 -07:00
Nicolas Pitre
ce9fbf16e0 index-pack: use hash_sha1_file()
Use hash_sha1_file() instead of duplicating code to compute object SHA1.
While at it make it accept a const pointer.

Signed-off-by: Nicolas Pitre <nico@cam.org>
Signed-off-by: Junio C Hamano <junkio@cox.net>
2007-03-20 22:09:57 -07:00
Linus Torvalds
456cdf6edb Fix loose object uncompression check.
The thing is, if the output buffer is empty, we should *still* actually
use the zlib routines to *unpack* that empty output buffer.

But we had a test that said "only unpack if we still expect more output".

So we wouldn't use up all the zlib stream, because we felt that we didn't
need it, because we already had all the bytes we wanted. And it was
"true": we did have all the output data. We just needed to also eat all
the input data!

We've had this bug before - thinking that we don't need to inflate()
anything because we already had it all..

Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Junio C Hamano <junkio@cox.net>
2007-03-19 23:13:17 -07:00