Граф коммитов

26 Коммитов

Автор SHA1 Сообщение Дата
Elijah Newren ef3ca95475 Add missing includes and forward declarations
I looped over the toplevel header files, creating a temporary two-line C
program for each consisting of
  #include "git-compat-util.h"
  #include $HEADER
This patch is the result of manually fixing errors in compiling those
tiny programs.

Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-08-15 11:52:09 -07:00
Derrick Stolee cfe83216e4 csum-file: refactor finalize_hashfile() method
If we want to use a hashfile on the temporary file for a lockfile, then
we need finalize_hashfile() to fully write the trailing hash but also keep
the file descriptor open.

Do this by adding a new CSUM_HASH_IN_STREAM flag along with a functional
change that checks this flag before writing the checksum to the stream.
This differs from previous behavior since it would be written if either
CSUM_CLOSE or CSUM_FSYNC is provided.

Signed-off-by: Derrick Stolee <dstolee@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-04-02 14:27:30 -07:00
Derrick Stolee f2af9f5e02 csum-file: rename hashclose() to finalize_hashfile()
The hashclose() method behaves very differently depending on the flags
parameter. In particular, the file descriptor is not always closed.

Perform a simple rename of "hashclose()" to "finalize_hashfile()" in
preparation for functional changes.

Signed-off-by: Derrick Stolee <dstolee@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-04-02 14:27:30 -07:00
brian m. carlson 4d2735005a csum-file: abstract uses of SHA-1
Convert several direct uses of SHA-1 to use the_hash_algo instead.
Convert one use of the constant 20 as well.

Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-02-02 11:28:41 -08:00
brian m. carlson 98a3beab6a csum-file: rename sha1file to hashfile
Rename struct sha1file to struct hashfile, along with all of its related
functions.

The transformation in this commit was made by global search-and-replace.

Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-02-02 11:28:41 -08:00
Junio C Hamano 3889e7a60c Merge branch 'jk/pack-bitmap'
* jk/pack-bitmap:
  pack-bitmap: do not use gcc packed attribute
2014-12-12 14:31:42 -08:00
Karsten Blees b5007211b6 pack-bitmap: do not use gcc packed attribute
The "__attribute__" flag may be a noop on some compilers.
That's OK as long as the code is correct without the
attribute, but in this case it is not. We would typically
end up with a struct that is 2 bytes too long due to struct
padding, breaking both reading and writing of bitmaps.

Instead of marshalling the data in a struct, let's just
provide helpers for reading and writing the appropriate
types. Besides being correct on all platforms, the result is
more efficient and simpler to read.

Signed-off-by: Karsten Blees <blees@dcon.de>
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2014-11-30 18:07:34 -08:00
Junio C Hamano f06a5e607d Merge branch 'jk/sha1write-void'
Code clean-up.

* jk/sha1write-void:
  do not pretend sha1write returns errors
2014-01-10 10:33:09 -08:00
Jeff King 9af270e8c2 do not pretend sha1write returns errors
The sha1write function returns an int, but it will always be
"0". The failure-prone parts of the function happen in the
"flush" callback, which cannot pass an error back to us. So
we just end up calling die() during the flush.

Let's just drop the return value altogether, as it only
confuses callers into thinking that it might be useful.

Only one call site actually checked the return value. We can
drop that check, since it just led to a die() anyway.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-12-26 11:50:20 -08:00
Jeff King e74435a516 sha1write: make buffer const-correct
We are passed a "void *" and write it out without ever
touching it; let's indicate that by using "const".

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-10-24 15:44:18 -07:00
Junio C Hamano 6c52614864 csum-file: introduce sha1file_checkpoint
It is useful to be able to rewind a check-summed file to a certain
previous state after writing data into it using sha1write() API. The
fast-import command does this after streaming a blob data to the packfile
being generated and then noticing that the same blob has already been
written, and it does this with a private code truncate_pack() that is
commented as "Yes, this is a layering violation".

Introduce two API functions, sha1file_checkpoint(), that allows the caller
to save a state of a sha1file, and then later revert it to the saved state.
Use it to reimplement truncate_pack().

Signed-off-by: Junio C Hamano <gitster@pobox.com>
2011-11-30 14:27:59 -08:00
Junio C Hamano e337a04de2 index-pack: --verify
Given an existing .pack file and the .idx file that describes it,
this new mode of operation reads and re-index the packfile and makes
sure the existing .idx file matches the result byte-for-byte.

All the objects in the .pack file are validated during this operation as
well.  Unlike verify-pack, which visits each object described in the .idx
file in the SHA-1 order, index-pack efficiently exploits the delta-chain
to avoid rebuilding the objects that are used as the base of deltified
objects over and over again while validating the objects, resulting in
much quicker verification of the .pack file and its .idx file.

This version however cannot verify a .pack/.idx pair with a handcrafted v2
index that uses 64-bit offset representation for offsets that would fit
within 31-bit. You can create such an .idx file by giving a custom offset
to --index-version option to the command.

Signed-off-by: Junio C Hamano <gitster@pobox.com>
2011-02-27 23:29:03 -08:00
Shawn O. Pearce e782e12f89 Merge branch 'maint'
* maint:
  rebase -i: do not fail when there is no commit to cherry-pick
  test-lib: fix color reset in say_color()
  fix pread()'s short read in index-pack

Conflicts:
	csum-file.c
2008-10-10 08:39:20 -07:00
Nicolas Pitre 838cd34664 fix pread()'s short read in index-pack
Since v1.6.0.2~13^2~ the completion of a thin pack uses sha1write() for
its ability to compute a SHA1 on the written data.  This also provides
data buffering which, along with commit 92392b4a45, will confuse pread()
whenever an appended object is 1) freed due to memory pressure because
of the depth-first delta processing, and 2) needed again because it has
many delta children, and 3) its data is still buffered by sha1write().

Let's fix the issue by simply forcing cached data out when such an
object is written so it can be pread()'d at leisure.

Signed-off-by: Nicolas Pitre <nico@cam.org>
Signed-off-by: Shawn O. Pearce <spearce@spearce.org>
2008-10-10 07:09:30 -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
Linus Torvalds 4c81b03e30 Make pack creation always fsync() the result
This means that we can depend on packs always being stable on disk,
simplifying a lot of the object serialization worries.  And unlike loose
objects, serializing pack creation IO isn't going to be a performance
killer.

Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2008-05-31 14:46:57 -07:00
Nicolas Pitre ec640ed1cf remove dead code from the csum-file interface
The provided name argument is always constant and valid in every
caller's context, so no need to have an array of PATH_MAX chars to copy
it into when a simple pointer will do.  Unfortunately that means getting
rid of wascally wabbits too.

The 'error' field is also unused.

Signed-off-by: Nicolas Pitre <nico@cam.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2007-11-05 12:55:33 -08:00
Nicolas Pitre 218558af59 make display of total transferred more accurate
The throughput display needs a delay period before accounting and
displaying anything.  Yet it might be called after some amount of data
has already been transferred.  The display of total data is therefore
accounted late and therefore smaller than the reality.

Let's call display_throughput() with an absolute amount of transferred
data instead of a relative number, and let the throughput code find the
relative amount of data by itself as needed.  This way the displayed
total is always exact.

Signed-off-by: Nicolas Pitre <nico@cam.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2007-11-05 12:53:14 -08:00
Nicolas Pitre 2a128d63dc add throughput display to git-push
This one triggers only when git-pack-objects is called with
--all-progress and --stdout which is the combination used by
git-push.

Signed-off-by: Nicolas Pitre <nico@cam.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2007-10-30 16:08:40 -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
Dana How 960ccca680 Custom compression levels for objects and packs
Add config variables pack.compression and core.loosecompression ,
and switch --compression=level to pack-objects.

Loose objects will be compressed using core.loosecompression if set,
else core.compression if set, else Z_BEST_SPEED.
Packed objects will be compressed using --compression=level if seen,
else pack.compression if set, else core.compression if set,
else Z_DEFAULT_COMPRESSION.  This is the "pack compression level".

Loose objects added to a pack undeltified will be recompressed
to the pack compression level if it is unequal to the current
loose compression level by the preceding rules,  or if the loose
object was written while core.legacyheaders = true.  Newly
deltified loose objects are always compressed to the current
pack compression level.

Previously packed objects added to a pack are recompressed
to the current pack compression level exactly when their
deltification status changes,  since the previous pack data
cannot be reused.

In either case,  the --no-reuse-object switch from the first
patch below will always force recompression to the current pack
compression level,  instead of assuming the pack compression level
hasn't changed and pack data can be reused when possible.

This applies on top of the following patches from Nicolas Pitre:
[PATCH] allow for undeltified objects not to be reused
[PATCH] make "repack -f" imply "pack-objects --no-reuse-object"

Signed-off-by: Dana L. How <danahow@gmail.com>
Signed-off-by: Junio C Hamano <junkio@cox.net>
2007-05-10 15:23:09 -07:00
Nicolas Pitre 78d1e84fe5 compute a CRC32 for each object as stored in a pack
The most important optimization for performance when repacking is the
ability to reuse data from a previous pack as is and bypass any delta
or even SHA1 computation by simply copying the raw data from one pack
to another directly.

The problem with  this is that any data corruption within a copied object
would go unnoticed and the new (repacked) pack would be self-consistent
with its own checksum despite containing a corrupted object.  This is a
real issue that already happened at least once in the past.

In some attempt to prevent this, we validate the copied data by inflating
it and making sure no error is signaled by zlib.  But this is still not
perfect as a significant portion of a pack content is made of object
headers and references to delta base objects which are not deflated and
therefore not validated when repacking actually making the pack data reuse
still not as safe as it could be.

Of course a full SHA1 validation could be performed, but that implies
full data inflating and delta replaying which is extremely costly, which
cost the data reuse optimization was designed to avoid in the first place.

So the best solution to this is simply to store a CRC32 of the raw pack
data for each object in the pack index.  This way any object in a pack can
be validated before being copied as is in another pack, including header
and any other non deflated data.

Why CRC32 instead of a faster checksum like Adler32?  Quoting Wikipedia:

   Jonathan Stone discovered in 2001 that Adler-32 has a weakness for very
   short messages. He wrote "Briefly, the problem is that, for very short
   packets, Adler32 is guaranteed to give poor coverage of the available
   bits. Don't take my word for it, ask Mark Adler. :-)" The problem is
   that sum A does not wrap for short messages. The maximum value of A for
   a 128-byte message is 32640, which is below the value 65521 used by the
   modulo operation. An extended explanation can be found in RFC 3309,
   which mandates the use of CRC32 instead of Adler-32 for SCTP, the
   Stream Control Transmission Protocol.

In the context of a GIT pack, we have lots of small objects, especially
deltas, which are likely to be quite small and in a size range for which
Adler32 is dimed not to be sufficient.  Another advantage of CRC32 is the
possibility for recovery from certain types of small corruptions like
single bit errors which are the most probable type of corruptions.

OK what this patch does is to compute the CRC32 of each object written to
a pack within pack-objects.  It is not written to the index yet and it is
obviously not validated when reusing pack data yet either.

Signed-off-by: Nicolas Pitre <nico@cam.org>
Signed-off-by: Junio C Hamano <junkio@cox.net>
2007-04-10 12:48:14 -07:00
Timo Sirainen 4ec99bf080 [PATCH] -Werror fixes
GCC's format __attribute__ is good for checking errors, especially
with -Wformat=2 parameter. This fixes most of the reported problems
against 2005-08-09 snapshot.
2005-08-09 22:28:19 -07:00
Linus Torvalds 4397f0148a csum-file: add "sha1fd()" to create a SHA1 csum file from an existing file descriptor
We'll use this soon to write pack-files to stdout.
2005-06-28 11:10:06 -07:00
Linus Torvalds e18088451d csum-file interface updates: return resulting SHA1
Also, make the writing of the SHA1 as a end-header be conditional: not
every user will necessarily want to write the SHA1 to the file itself,
even though current users do (but we migh end up using the same helper
functions for the object files themselves, that don't do this).

This also makes the packed index file contain the SHA1 of the packed
data file at the end (just before its own SHA1).  That way you can
validate the pairing of the two if you want to.
2005-06-26 22:01:46 -07:00
Linus Torvalds c38138cd78 git-pack-objects: write the pack files with a SHA1 csum
We want to be able to check their integrity later, and putting the
sha1-sum of the contents at the end is a good thing.  The writing
routines are generic, so we could try to re-use them for the index file,
instead of having the same logic duplicated.

Update unpack-objects to know about the extra 20 bytes at the end
of the index.
2005-06-26 20:27:56 -07:00