kernel/git - git - PowerEL Git System

Commit Graph

Author	SHA1	Message	Date
Junio C Hamano	8977c110b5	pack-check.c::verify_packfile(): don't run SHA-1 update on huge data Running the SHA1_Update() on the whole packfile in a single call revealed an overflow problem we had in the SHA-1 implementation on POWER architecture some time ago, which was fixed with commit `b47f509b` (June 19, 2006). Other SHA-1 implementations may have a similar problem. The sliding mmap() series already makes chunked calls to SHA1_Update(), so this patch itself will become moot when it graduates to "master", but in the meantime, run the hash function in smaller chunks to prevent possible future problems. Signed-off-by: Junio C Hamano <junkio@cox.net>	18 years ago
Shawn O. Pearce	079afb18fe	Loop over pack_windows when inflating/accessing data. When multiple mmaps start getting used for all pack file access it is not possible to get all data associated with a specific object in one contiguous memory region. This limitation prevents simply passing a single address and length to SHA1_Update or to inflate. Instead we need to loop until we have processed all data of interest. As we loop over the data we are always interested in reusing the same window 'cursor', as the prior window will no longer be of any use to us. This allows the use_pack() call to automatically decrement the use count of the prior window before setting up access for us to the next window. Within each loop we need to make use of the available length output parameter of use_pack() to tell us how many bytes are available in the current memory region, as we cannot tell otherwise. Signed-off-by: Shawn O. Pearce <spearce@spearce.org> Signed-off-by: Junio C Hamano <junkio@cox.net>	18 years ago
Shawn O. Pearce	03e79c88aa	Replace use_packed_git with window cursors. Part of the implementation concept of the sliding mmap window for pack access is to permit multiple windows per pack to be mapped independently. Since the inuse_cnt is associated with the mmap and not with the file, this value is in struct pack_window and needs to be incremented/decremented for each pack_window accessed by any code. To faciliate that implementation we need to replace all uses of use_packed_git() and unuse_packed_git() with a different API that follows struct pack_window objects rather than struct packed_git. The way this works is when we need to start accessing a pack for the first time we should setup a new window 'cursor' by declaring a local and setting it to NULL: struct pack_windows w_curs = NULL; To obtain the memory region which contains a specific section of the pack file we invoke use_pack(), supplying the address of our current window cursor: unsigned int len; unsigned char addr = use_pack(p, &w_curs, offset, &len); the returned address `addr` will be the first byte at `offset` within the pack file. The optional variable len will also be updated with the number of bytes remaining following the address. Multiple calls to use_pack() with the same window cursor will update the window cursor, moving it from one window to another when necessary. In this way each window cursor variable maintains only one struct pack_window inuse at a time. Finally before exiting the scope which originally declared the window cursor we must invoke unuse_pack() to unuse the current window (which may be different from the one that was first obtained from use_pack): unuse_pack(&w_curs); This implementation is still not complete with regards to multiple windows, as only one window per pack file is supported right now. Signed-off-by: Shawn O. Pearce <spearce@spearce.org> Signed-off-by: Junio C Hamano <junkio@cox.net>	18 years ago
Shawn O. Pearce	c41ee586dc	Refactor packed_git to prepare for sliding mmap windows. The idea behind the sliding mmap window pack reader implementation is to have multiple mmap regions active against the same pack file, thereby allowing the process to mmap in only the active/hot sections of the pack and reduce overall virtual address space usage. To implement this we need to refactor the mmap related data (pack_base, pack_use_cnt) out of struct packed_git and move them into a new struct pack_window. We are refactoring the code to support a single struct pack_window per packfile, thereby emulating the prior behavior of mmap'ing the entire pack file. Signed-off-by: Shawn O. Pearce <spearce@spearce.org> Signed-off-by: Junio C Hamano <junkio@cox.net>	18 years ago
Shawn O. Pearce	4d703a1a90	Replace unpack_entry_gently with unpack_entry. The unpack_entry_gently function currently has only two callers: the delta base resolution in sha1_file.c and the main loop of pack-check.c. Both of these must change to using unpack_entry directly when we implement sliding window mmap logic, so I'm doing it earlier to help break down the change set. This may cause a slight performance decrease for delta base resolution as well as for pack-check.c's verify_packfile(), as the pack use counter will be incremented and decremented for every object that is unpacked. Signed-off-by: Shawn O. Pearce <spearce@spearce.org> Signed-off-by: Junio C Hamano <junkio@cox.net>	18 years ago
Nicolas Pitre	43057304c0	many cleanups to sha1_file.c Those cleanups are mainly to set the table for the support of deltas with base objects referenced by offsets instead of sha1. This means that many pack lookup functions are converted to take a pack/offset tuple instead of a sha1. This eliminates many struct pack_entry usages since this structure carried redundent information in many cases, and it increased stack footprint needlessly for a couple recursively called functions that used to declare a local copy of it for every recursion loop. In the process, packed_object_info_detail() has been reorganized as well so to look much saner and more amenable to deltas with offset support. Finally the appropriate adjustments have been made to functions that depend on the above changes. But there is no functionality changes yet simply some code refactoring at this point. Signed-off-by: Nicolas Pitre <nico@cam.org> Signed-off-by: Junio C Hamano <junkio@cox.net>	18 years ago
David Rientjes	a89fccd281	Do not use memcmp(sha1_1, sha1_2, 20) with hardcoded length. Introduces global inline: hashcmp(const unsigned char sha1, const unsigned char sha2) Uses memcmp for comparison and returns the result based on the length of the hash name (a future runtime decision). Acked-by: Alex Riesen <raa.lkml@gmail.com> Signed-off-by: David Rientjes <rientjes@google.com> Signed-off-by: Junio C Hamano <junkio@cox.net>	18 years ago
Florian Forster	1d7f171c3a	Remove all void-pointer arithmetic. 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>	19 years ago
Junio C Hamano	55e1805dff	verify-pack: check integrity in a saner order. Check internal integrity to report corrupt pack or idx, and then check cross-integrity between idx and pack. Signed-off-by: Linus Torvalds <torvalds@osdl.org> Signed-off-by: Junio C Hamano <junkio@cox.net>	19 years ago
Junio C Hamano	473ab1659b	verify-pack -v: show delta-chain histogram. Signed-off-by: Junio C Hamano <junkio@cox.net>	19 years ago
Junio C Hamano	f8f135c9ba	packed objects: minor cleanup The delta depth is unsigned. Signed-off-by: Junio C Hamano <junkio@cox.net>	19 years ago
Nicolas Pitre	d60fc1c864	remove delta-against-self bit After experimenting with code to add the ability to encode a delta against part of the deltified file, it turns out that resulting packs are _bigger_ than when this ability is not used. The raw delta output might be smaller, but it doesn't compress as well using gzip with a negative net saving on average. Said bit would in fact be more useful to allow for encoding the copying of chunks larger than 64KB providing more savings with large files. This will correspond to packs version 3. While the current code still produces packs version 2, it is made future proof so pack versions 2 and 3 are accepted. Any pack version 2 are compatible with version 3 since the redefined bit was never used before. When enough time has passed, code to use that bit to produce version 3 packs could be added. Signed-off-by: Nicolas Pitre <nico@cam.org> Signed-off-by: Junio C Hamano <junkio@cox.net>	19 years ago
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.	20 years ago
Junio C Hamano	1038f0c0a1	[PATCH] Typofix an error message in pack-check.c The current error message does not make any sense. Signed-off-by: Junio C Hamano <junkio@cox.net> Signed-off-by: Linus Torvalds <torvalds@osdl.org>	20 years ago
Junio C Hamano	ad8c80a58f	[PATCH] Show more details of packfile with verify-pack -v. This implements show_pack_info() function used in verify-pack command when -v flag is used to obtain something like unpack-objects used to give when it was first written. It shows the following for each non-deltified object found in the pack: SHA1 type size offset For deltified objects, it shows this instead: SHA1 type size offset depth base_sha1 In order to get the output in the order that appear in the pack file for debugging purposes, you can do this: $ git-verify-pack -v packfile \| sort -n -k 4,4 Signed-off-by: Junio C Hamano <junkio@cox.net> Signed-off-by: Linus Torvalds <torvalds@osdl.org>	20 years ago
Junio C Hamano	f3bf922409	[PATCH] verify-pack updates. Nico pointed out that having verify_pack.c and verify-pack.c was confusing. Rename verify_pack.c to pack-check.c as suggested, and enhances the verification done quite a bit. - Built-in sha1_file unpacking knows that a base object of a deltified object _must_ be in the same pack, and takes advantage of that fact. - Earlier verify-pack command only checked the SHA1 sum for the entire pack file and did not look into its contents. It now checks everything idx file claims to have unpacks correctly. - It now has a hook to give more detailed information for objects contained in the pack under -v flag. Signed-off-by: Junio C Hamano <junkio@cox.net> Signed-off-by: Linus Torvalds <torvalds@osdl.org>	20 years ago
Junio C Hamano	f9253394a2	[PATCH] Add git-verify-pack command. Given a list of <pack>.idx files, this command validates the index file and the corresponding .pack file for consistency. This patch also uses the same validation mechanism in fsck-cache when the --full flag is used. During normal operation, sha1_file.c verifies that a given .idx file matches the .pack file by comparing the SHA1 checksum stored in .idx file and .pack file as a minimum sanity check. We may further want to check the pack signature and version when we map the pack, but that would be a separate patch. Earlier, errors to map a pack file was not flagged fatal but led to a random fatal error later. This version explicitly die()s when such an error is detected. Signed-off-by: Junio C Hamano <junkio@cox.net> Signed-off-by: Linus Torvalds <torvalds@osdl.org>	20 years ago

15 Commits (084ae0a7bd8a13dea7731dd7b6bf37f08c1cfc77)