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2018-04-02csum-file: refactor finalize_hashfile() methodLibravatar Derrick Stolee1-4/+4
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>
2018-04-02csum-file: rename hashclose() to finalize_hashfile()Libravatar Derrick Stolee1-1/+1
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>
2018-02-02csum-file: abstract uses of SHA-1Libravatar brian m. carlson1-5/+5
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>
2018-02-02csum-file: rename sha1file to hashfileLibravatar brian m. carlson1-18/+18
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>
2017-09-27prefer "!=" when checking read_in_full() resultLibravatar Jeff King1-1/+1
Comparing the result of read_in_full() using less-than is potentially dangerous, as a negative return value may be converted to an unsigned type and be considered a success. This is discussed further in 561598cfcf (read_pack_header: handle signed/unsigned comparison in read result, 2017-09-13). Each of these instances is actually fine in practice: - in get-tar-commit-id, the HEADERSIZE macro expands to a signed integer. If it were switched to an unsigned type (e.g., a size_t), then it would be a bug. - the other two callers check for a short read only after handling a negative return separately. This is a fine practice, but we'd prefer to model "!=" as a general rule. So all of these cases can be considered cleanups and not actual bugfixes. Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2015-03-19sha1fd_check: die when we cannot open the fileLibravatar Jeff King1-7/+3
Right now we return a NULL "struct sha1file" if we encounter an error. However, the sole caller (write_idx_file) does not check the return value, and will segfault if we hit this case. One option would be to handle the error in the caller. However, there's really nothing for it to do but die. This code path is hit during "git index-pack --verify"; after we verify the packfile, we check that the ".idx" we would generate from it is byte-wise identical to what is on disk. We hit the error (and segfault) if we can't open the .idx file (a likely cause of this is that somebody else ran "git repack -ad" while we were verifying). Since we can't complete the requested verification, we really have no choice but to die. Furthermore, the rest of the sha1fd_* functions simply die on errors. So if were to open the file successfully, for example, and then hit a read error, sha1write would call die() for us. So pushing the die() down into sha1fd_check keeps the interface consistent. Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2014-01-10Merge branch 'jk/sha1write-void'Libravatar Junio C Hamano1-2/+1
Code clean-up. * jk/sha1write-void: do not pretend sha1write returns errors
2013-12-26do not pretend sha1write returns errorsLibravatar Jeff King1-2/+1
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>
2013-10-24sha1write: make buffer const-correctLibravatar Jeff King1-3/+3
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>
2011-11-30csum-file: introduce sha1file_checkpointLibravatar Junio C Hamano1-0/+20
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>
2011-07-19Merge branch 'jc/index-pack'Libravatar Junio C Hamano1-1/+45
* jc/index-pack: verify-pack: use index-pack --verify index-pack: show histogram when emulating "verify-pack -v" index-pack: start learning to emulate "verify-pack -v" index-pack: a miniscule refactor index-pack --verify: read anomalous offsets from v2 idx file write_idx_file: need_large_offset() helper function index-pack: --verify write_idx_file: introduce a struct to hold idx customization options index-pack: group the delta-base array entries also by type Conflicts: builtin/verify-pack.c cache.h sha1_file.c
2011-04-03sparse: Fix errors and silence warningsLibravatar Stephen Boyd1-1/+1
* load_file() returns a void pointer but is using 0 for the return value * builtin/receive-pack.c forgot to include builtin.h * packet_trace_prefix can be marked static * ll_merge takes a pointer for its last argument, not an int * crc32 expects a pointer as the second argument but Z_NULL is defined to be 0 (see 38f4d13 sparse fix: Using plain integer as NULL pointer, 2006-11-18 for more info) Signed-off-by: Stephen Boyd <bebarino@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2011-02-27index-pack: --verifyLibravatar Junio C Hamano1-1/+45
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>
2009-06-27Convert existing die(..., strerror(errno)) to die_errno()Libravatar Thomas Rast1-3/+2
Change calls to die(..., strerror(errno)) to use the new die_errno(). In the process, also make slight style adjustments: at least state _something_ about the function that failed (instead of just printing the pathname), and put paths in single quotes. Signed-off-by: Thomas Rast <trast@student.ethz.ch> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2008-10-10Merge branch 'maint'Libravatar Shawn O. Pearce1-6/+12
* 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
2008-10-10fix pread()'s short read in index-packLibravatar Nicolas Pitre1-6/+12
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>
2008-10-02fix openssl headers conflicting with custom SHA1 implementationsLibravatar Nicolas Pitre1-4/+4
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>
2008-09-02sha1write: don't copy full sized buffersLibravatar Nicolas Pitre1-10/+17
No need to memcpy() source buffer data when we might just process the data in place instead of accumulating it into a separate buffer. This is the case when a whole buffer would have been copied, summed, written out and then discarded right away. Also move the CRC32 processing within the loop so the data is more likely to remain in the L1 CPU cache between the CRC32 sum, SHA1 sum and the write call. Signed-off-by: Nicolas Pitre <nico@cam.org> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2008-08-29pack-objects: use fixup_pack_header_footer()'s validation modeLibravatar Nicolas Pitre1-3/+3
When limiting the pack size, a new header has to be written to the pack and a new SHA1 computed. Make sure that the SHA1 of what is being read back matches the SHA1 of what was written. Signed-off-by: Nicolas Pitre <nico@cam.org> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2008-05-31Make pack creation always fsync() the resultLibravatar Linus Torvalds1-2/+5
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>
2007-11-05remove dead code from the csum-file interfaceLibravatar Nicolas Pitre1-12/+2
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>
2007-11-05make display of total transferred more accurateLibravatar Nicolas Pitre1-1/+3
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>
2007-10-30add throughput display to git-pushLibravatar Nicolas Pitre1-0/+8
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>
2007-10-17pack-objects.c: fix some global variable abuse and memory leaksLibravatar Nicolas Pitre1-9/+14
To keep things well layered, sha1close() now returns the file descriptor when it doesn't close the file. An ugly cast was added to the return of write_idx_file() to avoid a warning. A proper fix will come separately. Signed-off-by: Nicolas Pitre <nico@cam.org> Signed-off-by: Shawn O. Pearce <spearce@spearce.org>
2007-06-13More staticLibravatar Junio C Hamano1-55/+0
There still are quite a few symbols that ought to be static. Signed-off-by: Junio C Hamano <gitster@pobox.com>
2007-05-20Alter sha1close() 3rd argument to request flush onlyLibravatar Dana L. How1-3/+5
update=0 suppressed writing the final SHA-1 but was not used. Now final=0 suppresses SHA-1 finalization, SHA-1 writing, and closing -- in other words, only flush the buffer. Signed-off-by: Dana L. How <danahow@gmail.com> Signed-off-by: Junio C Hamano <junkio@cox.net>
2007-05-10Custom compression levels for objects and packsLibravatar Dana How1-2/+2
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>
2007-04-10compute a CRC32 for each object as stored in a packLibravatar Nicolas Pitre1-0/+14
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>
2006-08-23Convert memcpy(a,b,20) to hashcpy(a,b).Libravatar Shawn Pearce1-1/+1
This abstracts away the size of the hash values when copying them from memory location to memory location, much as the introduction of hashcmp abstracted away hash value comparsion. A few call sites were using char* rather than unsigned char* so I added the cast rather than open hashcpy to be void*. This is a reasonable tradeoff as most call sites already use unsigned char* and the existing hashcmp is also declared to be unsigned char*. [jc: Splitted the patch to "master" part, to be followed by a patch for merge-recursive.c which is not in "master" yet. Fixed the cast in the latter hunk to combine-diff.c which was wrong in the original. Also converted ones left-over in combine-diff.c, diff-lib.c and upload-pack.c ] Signed-off-by: Shawn O. Pearce <spearce@spearce.org> Signed-off-by: Junio C Hamano <junkio@cox.net>
2006-08-14Make sha1flush void and remove conditional return.Libravatar David Rientjes1-2/+2
Signed-off-by: David Rientjes <rientjes@google.com> Signed-off-by: Junio C Hamano <junkio@cox.net>
2006-07-03Make zlib compression level configurable, and change default.Libravatar Joachim B Haga1-1/+1
With the change in default, "git add ." on kernel dir is about twice as fast as before, with only minimal (0.5%) change in object size. The speed difference is even more noticeable when committing large files, which is now up to 8 times faster. The configurability is through setting core.compression = [-1..9] which maps to the zlib constants; -1 is the default, 0 is no compression, and 1..9 are various speed/size tradeoffs, 9 being slowest. Signed-off-by: Joachim B Haga (cjhaga@fys.uio.no) Acked-by: Linus Torvalds <torvalds@osdl.org> Signed-off-by: Junio C Hamano <junkio@cox.net>
2006-06-20Remove all void-pointer arithmetic.Libravatar Florian Forster1-2/+2
ANSI C99 doesn't allow void-pointer arithmetic. This patch fixes this in various ways. Usually the strategy that required the least changes was used. Signed-off-by: Florian Forster <octo@verplant.org> Signed-off-by: Junio C Hamano <junkio@cox.net>
2005-12-19xread/xwrite: do not worry about EINTR at calling sites.Libravatar Junio C Hamano1-3/+1
We had errno==EINTR check after read(2)/write(2) sprinkled all over the places, always doing continue. Consolidate them into xread()/xwrite() wrapper routines. Credits for suggestion goes to HPA -- bugs are mine. Signed-off-by: Junio C Hamano <junkio@cox.net>
2005-08-08[PATCH] Plug memory leak in sha1close()Libravatar Sergey Vlasov1-0/+1
sha1create() and sha1fd() malloc the returned struct sha1file; sha1close() should free it. Signed-off-by: Sergey Vlasov <vsu@altlinux.ru> Signed-off-by: Junio C Hamano <junkio@cox.net>
2005-07-06[PATCH] Let umask do its work upon filesystem object creation.Libravatar Junio C Hamano1-1/+1
IIRC our strategy was to let the users' umask take care of the final mode bits. This patch fixes places that deviate from it. Signed-off-by: Junio C Hamano <junkio@cox.net> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-06-28csum-file: add "sha1fd()" to create a SHA1 csum file from an existing file ↵Libravatar Linus Torvalds1-0/+20
descriptor We'll use this soon to write pack-files to stdout.
2005-06-27csum-file: fix missing buf pointer updateLibravatar Linus Torvalds1-0/+1
This would create broken pack archives for anything nontrivial.
2005-06-26csum-file interface updates: return resulting SHA1Libravatar Linus Torvalds1-10/+16
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.
2005-06-26git-pack-objects: write the pack files with a SHA1 csumLibravatar Linus Torvalds1-0/+120
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.