Extract verify_pack_index for reuse from verify_pack
[git/git.git] / pack.h
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1#ifndef PACK_H
2#define PACK_H
3
1974632c 4#include "object.h"
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5
6/*
7 * Packed object header
8 */
9#define PACK_SIGNATURE 0x5041434b /* "PACK" */
29f049a0 10#define PACK_VERSION 2
d60fc1c8 11#define pack_version_ok(v) ((v) == htonl(2) || (v) == htonl(3))
a733cb60 12struct pack_header {
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13 uint32_t hdr_signature;
14 uint32_t hdr_version;
15 uint32_t hdr_entries;
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16};
17
df1b059d 18/*
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19 * The first four bytes of index formats later than version 1 should
20 * start with this signature, as all older git binaries would find this
21 * value illegal and abort reading the file.
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22 *
23 * This is the case because the number of objects in a packfile
24 * cannot exceed 1,431,660,000 as every object would need at least
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25 * 3 bytes of data and the overall packfile cannot exceed 4 GiB with
26 * version 1 of the index file due to the offsets limited to 32 bits.
27 * Clearly the signature exceeds this maximum.
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28 *
29 * Very old git binaries will also compare the first 4 bytes to the
30 * next 4 bytes in the index and abort with a "non-monotonic index"
31 * error if the second 4 byte word is smaller than the first 4
32 * byte word. This would be true in the proposed future index
33 * format as idx_signature would be greater than idx_version.
34 */
35#define PACK_IDX_SIGNATURE 0xff744f63 /* "\377tOc" */
36
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37/* These may be overridden by command-line parameters */
38extern uint32_t pack_idx_default_version;
39extern uint32_t pack_idx_off32_limit;
40
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41/*
42 * Packed object index header
43 */
44struct pack_idx_header {
45 uint32_t idx_signature;
46 uint32_t idx_version;
47};
48
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49/*
50 * Common part of object structure used for write_idx_file
51 */
52struct pack_idx_entry {
53 unsigned char sha1[20];
54 uint32_t crc32;
55 off_t offset;
56};
57
3bb72562 58extern const char *write_idx_file(const char *index_name, struct pack_idx_entry **objects, int nr_objects, unsigned char *sha1);
c41a4a94 59extern int check_pack_crc(struct packed_git *p, struct pack_window **w_curs, off_t offset, off_t len, unsigned int nr);
9b0aa728 60extern int verify_pack_index(struct packed_git *);
77d3ecee 61extern int verify_pack(struct packed_git *);
abeb40e5 62extern void fixup_pack_header_footer(int, unsigned char *, const char *, uint32_t, unsigned char *, off_t);
106764e6 63extern char *index_pack_lockfile(int fd);
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64
65#define PH_ERROR_EOF (-1)
66#define PH_ERROR_PACK_SIGNATURE (-2)
67#define PH_ERROR_PROTOCOL (-3)
68extern int read_pack_header(int fd, struct pack_header *);
a733cb60 69#endif