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e337a04de2
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>
78 lines
2.4 KiB
C
78 lines
2.4 KiB
C
#ifndef PACK_H
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#define PACK_H
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#include "object.h"
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/*
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* Packed object header
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*/
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#define PACK_SIGNATURE 0x5041434b /* "PACK" */
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#define PACK_VERSION 2
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#define pack_version_ok(v) ((v) == htonl(2) || (v) == htonl(3))
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struct pack_header {
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uint32_t hdr_signature;
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uint32_t hdr_version;
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uint32_t hdr_entries;
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};
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/*
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* The first four bytes of index formats later than version 1 should
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* start with this signature, as all older git binaries would find this
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* value illegal and abort reading the file.
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*
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* This is the case because the number of objects in a packfile
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* cannot exceed 1,431,660,000 as every object would need at least
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* 3 bytes of data and the overall packfile cannot exceed 4 GiB with
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* version 1 of the index file due to the offsets limited to 32 bits.
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* Clearly the signature exceeds this maximum.
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*
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* Very old git binaries will also compare the first 4 bytes to the
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* next 4 bytes in the index and abort with a "non-monotonic index"
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* error if the second 4 byte word is smaller than the first 4
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* byte word. This would be true in the proposed future index
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* format as idx_signature would be greater than idx_version.
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*/
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#define PACK_IDX_SIGNATURE 0xff744f63 /* "\377tOc" */
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struct pack_idx_option {
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unsigned flags;
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/* flag bits */
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#define WRITE_IDX_VERIFY 01
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uint32_t version;
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uint32_t off32_limit;
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};
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extern void reset_pack_idx_option(struct pack_idx_option *);
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/*
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* Packed object index header
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*/
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struct pack_idx_header {
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uint32_t idx_signature;
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uint32_t idx_version;
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};
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/*
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* Common part of object structure used for write_idx_file
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*/
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struct pack_idx_entry {
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unsigned char sha1[20];
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uint32_t crc32;
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off_t offset;
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};
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extern const char *write_idx_file(const char *index_name, struct pack_idx_entry **objects, int nr_objects, const struct pack_idx_option *, unsigned char *sha1);
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extern int check_pack_crc(struct packed_git *p, struct pack_window **w_curs, off_t offset, off_t len, unsigned int nr);
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extern int verify_pack_index(struct packed_git *);
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extern int verify_pack(struct packed_git *);
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extern void fixup_pack_header_footer(int, unsigned char *, const char *, uint32_t, unsigned char *, off_t);
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extern char *index_pack_lockfile(int fd);
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extern int encode_in_pack_object_header(enum object_type, uintmax_t, unsigned char *);
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#define PH_ERROR_EOF (-1)
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#define PH_ERROR_PACK_SIGNATURE (-2)
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#define PH_ERROR_PROTOCOL (-3)
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extern int read_pack_header(int fd, struct pack_header *);
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#endif
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