Merge branch 'mh/notes-duplicate-entries'
[git/git.git] / pack.h
CommitLineData
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1#ifndef PACK_H
2#define PACK_H
3
1974632c 4#include "object.h"
c0ad4657 5#include "csum-file.h"
a733cb60 6
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7struct repository;
8
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9/*
10 * Packed object header
11 */
12#define PACK_SIGNATURE 0x5041434b /* "PACK" */
29f049a0 13#define PACK_VERSION 2
d60fc1c8 14#define pack_version_ok(v) ((v) == htonl(2) || (v) == htonl(3))
a733cb60 15struct pack_header {
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16 uint32_t hdr_signature;
17 uint32_t hdr_version;
18 uint32_t hdr_entries;
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19};
20
df1b059d 21/*
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22 * The first four bytes of index formats later than version 1 should
23 * start with this signature, as all older git binaries would find this
24 * value illegal and abort reading the file.
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25 *
26 * This is the case because the number of objects in a packfile
27 * cannot exceed 1,431,660,000 as every object would need at least
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28 * 3 bytes of data and the overall packfile cannot exceed 4 GiB with
29 * version 1 of the index file due to the offsets limited to 32 bits.
30 * Clearly the signature exceeds this maximum.
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31 *
32 * Very old git binaries will also compare the first 4 bytes to the
33 * next 4 bytes in the index and abort with a "non-monotonic index"
34 * error if the second 4 byte word is smaller than the first 4
35 * byte word. This would be true in the proposed future index
36 * format as idx_signature would be greater than idx_version.
37 */
38#define PACK_IDX_SIGNATURE 0xff744f63 /* "\377tOc" */
39
ebcfb379 40struct pack_idx_option {
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41 unsigned flags;
42 /* flag bits */
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43#define WRITE_IDX_VERIFY 01 /* verify only, do not write the idx file */
44#define WRITE_IDX_STRICT 02
e337a04d 45
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46 uint32_t version;
47 uint32_t off32_limit;
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48
49 /*
50 * List of offsets that would fit within off32_limit but
51 * need to be written out as 64-bit entity for byte-for-byte
52 * verification.
53 */
54 int anomaly_alloc, anomaly_nr;
55 uint32_t *anomaly;
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56};
57
55454427 58void reset_pack_idx_option(struct pack_idx_option *);
aa7e44bf 59
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60/*
61 * Packed object index header
62 */
63struct pack_idx_header {
64 uint32_t idx_signature;
65 uint32_t idx_version;
66};
67
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68/*
69 * Common part of object structure used for write_idx_file
70 */
71struct pack_idx_entry {
e6a492b7 72 struct object_id oid;
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73 uint32_t crc32;
74 off_t offset;
75};
76
c9486eb0 77
1e49f22f 78struct progress;
ec9d2249 79/* Note, the data argument could be NULL if object type is blob */
9fd75046 80typedef int (*verify_fn)(const struct object_id *, enum object_type, unsigned long, void*, int*);
c9486eb0 81
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82const char *write_idx_file(const char *index_name, struct pack_idx_entry **objects, int nr_objects, const struct pack_idx_option *, const unsigned char *sha1);
83int check_pack_crc(struct packed_git *p, struct pack_window **w_curs, off_t offset, off_t len, unsigned int nr);
84int verify_pack_index(struct packed_git *);
85int verify_pack(struct repository *, struct packed_git *, verify_fn fn, struct progress *, uint32_t);
86off_t write_pack_header(struct hashfile *f, uint32_t);
87void fixup_pack_header_footer(int, unsigned char *, const char *, uint32_t, unsigned char *, off_t);
88char *index_pack_lockfile(int fd);
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89
90/*
91 * The "hdr" output buffer should be at least this big, which will handle sizes
92 * up to 2^67.
93 */
94#define MAX_PACK_OBJECT_HEADER 10
55454427 95int encode_in_pack_object_header(unsigned char *hdr, int hdr_len,
ad6dad09 96 enum object_type, uintmax_t);
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97
98#define PH_ERROR_EOF (-1)
99#define PH_ERROR_PACK_SIGNATURE (-2)
100#define PH_ERROR_PROTOCOL (-3)
55454427 101int read_pack_header(int fd, struct pack_header *);
cdf9db3c 102
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103struct hashfile *create_tmp_packfile(char **pack_tmp_name);
104void finish_tmp_packfile(struct strbuf *name_buffer, const char *pack_tmp_name, struct pack_idx_entry **written_list, uint32_t nr_written, struct pack_idx_option *pack_idx_opts, unsigned char sha1[]);
cdf9db3c 105
a733cb60 106#endif