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2006-12-29pack-objects: fix use of use_pack().Libravatar Junio C Hamano1-2/+5
The code calls use_pack() to make that the variably encoded offset fits in the mmap'ed window, but it forgot that the operation gives the pointer to the beginning of the asked region. Signed-off-by: Junio C Hamano <junkio@cox.net>
2006-12-29Fix random segfaults in pack-objects.Libravatar Shawn O. Pearce1-3/+4
Junio noticed that 'non-trivial' pushes were failing if executed using the sliding window mmap changes. This was somewhat difficult to track down as the failure was appearing randomly. It turns out this was a failure caused by the delta base reference (either ref or offset format) spanning over the end of a mmap window. The error in pack-objects was we were not recalling use_pack after the object header was unpacked, and therefore we did not get the promise of at least 20 bytes in the buffer for the delta base parsing. This would case later memcmp() calls to walk into unassigned address space at the end of the window. The reason Junio and I had hard time tracking this down in current Git repositories is we were both probably packing with offset deltas, which minimized the odds of the delta base reference spanning over the end of the mmap window. Stepping back and repacking with version 1.3.3 (which only supported reference deltas) increased the likelyhood of seeing the bug. The correct technique (as used in sha1_file.c) is to invoke use_pack() after unpack_object_header_gently to ensure we have enough data available for the delta base decoding. Signed-off-by: Shawn O. Pearce <spearce@spearce.org> Signed-off-by: Junio C Hamano <junkio@cox.net>
2006-12-29Loop over pack_windows when inflating/accessing data.Libravatar Shawn O. Pearce1-6/+52
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>
2006-12-29Replace use_packed_git with window cursors.Libravatar Shawn O. Pearce1-9/+7
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>
2006-12-29Refactor packed_git to prepare for sliding mmap windows.Libravatar Shawn O. Pearce1-2/+2
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>
2006-12-20Teach git-repack to preserve objects referred to by reflog entries.Libravatar Junio C Hamano1-1/+2
This adds a new option --reflog to pack-objects and revision machinery; do not bother documenting it for now, since this is only useful for local repacking. When the option is passed, objects reachable from reflog entries are marked as interesting while computing the set of objects to pack. Signed-off-by: Junio C Hamano <junkio@cox.net>
2006-12-20simplify inclusion of system header files.Libravatar Junio C Hamano1-2/+0
This is a mechanical clean-up of the way *.c files include system header files. (1) sources under compat/, platform sha-1 implementations, and xdelta code are exempt from the following rules; (2) the first #include must be "git-compat-util.h" or one of our own header file that includes it first (e.g. config.h, builtin.h, pkt-line.h); (3) system headers that are included in "git-compat-util.h" need not be included in individual C source files. (4) "git-compat-util.h" does not have to include subsystem specific header files (e.g. expat.h). Signed-off-by: Junio C Hamano <junkio@cox.net>
2006-11-29pack-objects: remove redundent status informationLibravatar Nicolas Pitre1-2/+4
The final 'nr_result' and 'written' values must always be the same otherwise we're in deep trouble. So let's remove a redundent report. And for paranoia sake let's make sure those two variables are actually equal after all objects are written (one never knows). Signed-off-by: Nicolas Pitre <nico@cam.org> Signed-off-by: Junio C Hamano <junkio@cox.net>
2006-11-17pack-objects: tweak "do not even attempt delta" heuristicsLibravatar Junio C Hamano1-1/+3
The heuristics to give up deltification when both the source and the target are both in the same pack affects negatively when we are repacking the subset of objects in the existing pack. This caused any incremental updates to use suboptimal packs. Tweak the heuristics to avoid this problem. Signed-off-by: Junio C Hamano <junkio@cox.net>
2006-11-07git-pack-objects progress flag documentation and cleanupLibravatar Nicolas Pitre1-9/+10
This adds documentation for --progress and --all-progress, remove a duplicate --progress handling and make usage string more readable. Signed-off-by: Nicolas Pitre <nico@cam.org> Signed-off-by: Junio C Hamano <junkio@cox.net>
2006-11-01make git-push a bit more verboseLibravatar Nicolas Pitre1-7/+11
Currently git-push displays progress status for the local packing of objects to send, but nothing once it starts to push it over the connection. Having progress status in that later case is especially nice when pushing lots of objects over a slow network link. Signed-off-by: Nicolas Pitre <nico@cam.org> Signed-off-by: Junio C Hamano <junkio@cox.net>
2006-10-10pack-objects: document --delta-base-offset optionLibravatar Junio C Hamano1-1/+1
Signed-off-by: Junio C Hamano <junkio@cox.net>
2006-09-27allow delta data reuse even if base object is a preferred baseLibravatar Nicolas Pitre1-1/+1
Signed-off-by: Nicolas Pitre <nico@cam.org> Signed-off-by: Junio C Hamano <junkio@cox.net>
2006-09-27zap a debug remnantLibravatar Nicolas Pitre1-1/+0
Signed-off-by: Nicolas Pitre <nico@cam.org> Signed-off-by: Junio C Hamano <junkio@cox.net>
2006-09-27make pack data reuse compatible with both delta typesLibravatar Nicolas Pitre1-74/+130
This is the missing part to git-pack-objects allowing it to reuse delta data to/from any of the two delta types. It can reuse delta from any type, and it outputs base offsets when --allow-delta-base-offset is provided and the base is also included in the pack. Otherwise it outputs base sha1 references just like it always did. Signed-off-by: Nicolas Pitre <nico@cam.org> Signed-off-by: Junio C Hamano <junkio@cox.net>
2006-09-27make git-pack-objects able to create deltas with offset to baseLibravatar Nicolas Pitre1-14/+33
This is enabled with --delta-base-offset only, and doesn't work with pack data reuse yet. The idea is to allow for the fetch protocol to use an extension flag to notify the remote end that --delta-base-offset can be used with git-pack-objects. Eventually git-repack will always provide this flag. With this, all delta base objects are now pushed before deltas that depend on them. This is a requirements for OBJ_OFS_DELTA. This is not a requirement for OBJ_REF_DELTA but always doing so makes the code simpler. Signed-off-by: Nicolas Pitre <nico@cam.org> Signed-off-by: Junio C Hamano <junkio@cox.net>
2006-09-27introduce delta objects with offset to baseLibravatar Nicolas Pitre1-8/+8
This adds a new object, namely OBJ_OFS_DELTA, renames OBJ_DELTA to OBJ_REF_DELTA to better make the distinction between those two delta objects, and adds support for the handling of those new delta objects in sha1_file.c only. The OBJ_OFS_DELTA contains a relative offset from the delta object's position in a pack instead of the 20-byte SHA1 reference to identify the base object. Since the base is likely to be not so far away, the relative offset is more likely to have a smaller encoding on average than an absolute offset. And for those delta objects the base must always be stored first because there is no way to know the distance of later objects when streaming a pack. Hence this relative offset is always meant to be negative. The offset encoding is slightly denser than the one used for object size -- credits to <linux@horizon.com> (whoever this is) for bringing it to my attention. This allows for pack size reduction between 3.2% (Linux-2.6) to over 5% (linux-historic). Runtime pack access should be faster too since delta replay does skip a search in the pack index for each delta in a chain. Signed-off-by: Nicolas Pitre <nico@cam.org> Signed-off-by: Junio C Hamano <junkio@cox.net>
2006-09-23many cleanups to sha1_file.cLibravatar Nicolas Pitre1-4/+4
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>
2006-09-12pack-objects: document --revs, --unpacked and --all.Libravatar Junio C Hamano1-1/+1
Signed-off-by: Junio C Hamano <junkio@cox.net>
2006-09-07pack-objects: further work on internal rev-list logic.Libravatar Junio C Hamano1-60/+39
This teaches the internal rev-list logic to understand options that are needed for pack handling: --all, --unpacked, and --thin. It also moves two functions from builtin-rev-list to list-objects so that the two programs can share more code. Signed-off-by: Junio C Hamano <junkio@cox.net>
2006-09-07pack-objects: run rev-list equivalent internally.Libravatar Junio C Hamano1-82/+215
Instead of piping the rev-list output from its standard input, you can say: pack-objects --all --unpacked --revs pack and feed the rev parameters you would otherwise give the rev-list on its command line from the standard input. In other words: echo 'master..next' | pack-objects --revs pack and rev-list --objects master..next | pack-objects pack are equivalent. Signed-off-by: Junio C Hamano <junkio@cox.net>
2006-09-03more lightweight revalidation while reusing deflated stream in packingLibravatar Junio C Hamano1-29/+52
When copying from an existing pack and when copying from a loose object with new style header, the code makes sure that the piece we are going to copy out inflates well and inflate() consumes the data in full while doing so. The check to see if the xdelta really apply is quite expensive as you described, because you would need to have the image of the base object which can be represented as a delta against something else. Signed-off-by: Junio C Hamano <junkio@cox.net>
2006-09-03pack-objects: fix thinko in revalidate codeLibravatar Junio C Hamano1-6/+7
When revalidating an entry from an existing pack entry->size and entry->type are not necessarily the size of the final object when the entry is deltified, but for base objects they must match. Signed-off-by: Junio C Hamano <junkio@cox.net>
2006-09-02pack-objects: re-validate data we copy from elsewhere.Libravatar Junio C Hamano1-4/+63
When reusing data from an existing pack and from a new style loose objects, we used to just copy it staight into the resulting pack. Instead make sure they are not corrupt, but do so only when we are not streaming to stdout, in which case the receiving end will do the validation either by unpacking the stream or by constructing the .idx file. Signed-off-by: Junio C Hamano <junkio@cox.net>
2006-08-23Convert memcpy(a,b,20) to hashcpy(a,b).Libravatar Shawn Pearce1-3/+3
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>
2006-08-17Do not use memcmp(sha1_1, sha1_2, 20) with hardcoded length.Libravatar David Rientjes1-4/+4
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>
2006-08-15remove unnecessary initializationsLibravatar David Rientjes1-14/+14
[jc: I needed to hand merge the changes to the updated codebase, so the result needs to be checked.] Signed-off-by: David Rientjes <rientjes@google.com> Signed-off-by: Junio C Hamano <junkio@cox.net>
2006-08-12Merge branch 'jc/pack-objects'Libravatar Junio C Hamano1-0/+16
2006-08-03Make git-pack-objects a builtinLibravatar Matthias Kestenholz1-0/+1376
Signed-off-by: Matthias Kestenholz <matthias@spinlock.ch> Signed-off-by: Junio C Hamano <junkio@cox.net>