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git/pack.h

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Change pack file format. Hopefully for the last time. This also adds a header with a signature, version info, and the number of objects to the pack file. It also encodes the file length and type more efficiently.
2005-06-29 05:21:02 +08:00
#ifndef PACK_H
#define PACK_H
Make git pack files use little-endian size encoding This makes it match the new delta encoding, and admittedly makes the code easier to follow. This also updates the PACK file version to 2, since this (and the delta encoding change in the previous commit) are incompatible with the old format.
2005-06-29 13:15:57 +08:00
/*
* The packed object type is stored in 3 bits.
* The type value 0 is a reserved prefix if ever there is more than 7
* object types, or any future format extensions.
*/
Change pack file format. Hopefully for the last time. This also adds a header with a signature, version info, and the number of objects to the pack file. It also encodes the file length and type more efficiently.
2005-06-29 05:21:02 +08:00
enum object_type {
Make git pack files use little-endian size encoding This makes it match the new delta encoding, and admittedly makes the code easier to follow. This also updates the PACK file version to 2, since this (and the delta encoding change in the previous commit) are incompatible with the old format.
2005-06-29 13:15:57 +08:00
OBJ_EXT = 0,
OBJ_COMMIT = 1,
OBJ_TREE = 2,
OBJ_BLOB = 3,
OBJ_TAG = 4,
/* 5/6 for future expansion */
OBJ_DELTA = 7,
Change pack file format. Hopefully for the last time. This also adds a header with a signature, version info, and the number of objects to the pack file. It also encodes the file length and type more efficiently.
2005-06-29 05:21:02 +08:00
};
/*
* Packed object header
*/
#define PACK_SIGNATURE 0x5041434b /* "PACK" */
Make git pack files use little-endian size encoding This makes it match the new delta encoding, and admittedly makes the code easier to follow. This also updates the PACK file version to 2, since this (and the delta encoding change in the previous commit) are incompatible with the old format.
2005-06-29 13:15:57 +08:00
#define PACK_VERSION 2
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>
2006-02-10 06:50:04 +08:00
#define pack_version_ok(v) ((v) == htonl(2) || (v) == htonl(3))
Change pack file format. Hopefully for the last time. This also adds a header with a signature, version info, and the number of objects to the pack file. It also encodes the file length and type more efficiently.
2005-06-29 05:21:02 +08:00
struct pack_header {
unsigned int hdr_signature;
unsigned int hdr_version;
unsigned int hdr_entries;
};
[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>
2005-07-01 08:15:39 +08:00
extern int verify_pack(struct packed_git *, int);
pack-objects: reuse data from existing packs. When generating a new pack, notice if we have already needed objects in existing packs. If an object is stored deltified, and its base object is also what we are going to pack, then reuse the existing deltified representation unconditionally, bypassing all the expensive find_deltas() and try_deltas() calls. Also, notice if what we are going to write out exactly match what is already in an existing pack (either deltified or just compressed). In such a case, we can just copy it instead of going through the usual uncompressing & recompressing cycle. Without this patch, in linux-2.6 repository with about 1500 loose objects and a single mega pack: $ git-rev-list --objects v2.6.16-rc3 >RL $ wc -l RL 184141 RL $ time git-pack-objects p <RL Generating pack... Done counting 184141 objects. Packing 184141 objects.................... a1fc7b3e537fcb9b3c46b7505df859f0a11e79d2 real 12m4.323s user 11m2.560s sys 0m55.950s With this patch, the same input: $ time ../git.junio/git-pack-objects q <RL Generating pack... Done counting 184141 objects. Packing 184141 objects..................... a1fc7b3e537fcb9b3c46b7505df859f0a11e79d2 Total 184141, written 184141, reused 182441 real 1m2.608s user 0m55.090s sys 0m1.830s Signed-off-by: Junio C Hamano <junkio@cox.net>
2006-02-16 09:34:29 +08:00
extern int check_reuse_pack_delta(struct packed_git *, unsigned long,
unsigned char *, unsigned long *,
enum object_type *);
Change pack file format. Hopefully for the last time. This also adds a header with a signature, version info, and the number of objects to the pack file. It also encodes the file length and type more efficiently.
2005-06-29 05:21:02 +08:00
#endif
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