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1#ifndef PACK_H
2#define PACK_H
3
4#include "object.h"
5#include "csum-file.h"
6
7struct packed_git;
8struct pack_window;
9struct repository;
10
11/*
12 * Packed object header
13 */
14#define PACK_SIGNATURE 0x5041434b /* "PACK" */
15#define PACK_VERSION 2
16#define pack_version_ok(v) pack_version_ok_native(ntohl(v))
17#define pack_version_ok_native(v) ((v) == 2 || (v) == 3)
18struct pack_header {
19 uint32_t hdr_signature;
20 uint32_t hdr_version;
21 uint32_t hdr_entries;
22};
23
24/*
25 * The first four bytes of index formats later than version 1 should
26 * start with this signature, as all older git binaries would find this
27 * value illegal and abort reading the file.
28 *
29 * This is the case because the number of objects in a packfile
30 * cannot exceed 1,431,660,000 as every object would need at least
31 * 3 bytes of data and the overall packfile cannot exceed 4 GiB with
32 * version 1 of the index file due to the offsets limited to 32 bits.
33 * Clearly the signature exceeds this maximum.
34 *
35 * Very old git binaries will also compare the first 4 bytes to the
36 * next 4 bytes in the index and abort with a "non-monotonic index"
37 * error if the second 4 byte word is smaller than the first 4
38 * byte word. This would be true in the proposed future index
39 * format as idx_signature would be greater than idx_version.
40 */
41#define PACK_IDX_SIGNATURE 0xff744f63 /* "\377tOc" */
42
43struct pack_idx_option {
44 unsigned flags;
45 /* flag bits */
46#define WRITE_IDX_VERIFY 01 /* verify only, do not write the idx file */
47#define WRITE_IDX_STRICT 02
48#define WRITE_REV 04
49#define WRITE_REV_VERIFY 010
50#define WRITE_MTIMES 020
51
52 uint32_t version;
53 uint32_t off32_limit;
54
55 /*
56 * List of offsets that would fit within off32_limit but
57 * need to be written out as 64-bit entity for byte-for-byte
58 * verification.
59 */
60 int anomaly_alloc, anomaly_nr;
61 uint32_t *anomaly;
62
63 size_t delta_base_cache_limit;
64};
65
66void reset_pack_idx_option(struct pack_idx_option *);
67
68/*
69 * Packed object index header
70 */
71struct pack_idx_header {
72 uint32_t idx_signature;
73 uint32_t idx_version;
74};
75
76/*
77 * Common part of object structure used for write_idx_file
78 */
79struct pack_idx_entry {
80 struct object_id oid;
81 uint32_t crc32;
82 off_t offset;
83};
84
85
86struct progress;
87/* Note, the data argument could be NULL if object type is blob */
88typedef int (*verify_fn)(const struct object_id *, enum object_type, unsigned long, void*, int*);
89
90const char *write_idx_file(struct repository *repo,
91 const char *index_name,
92 struct pack_idx_entry **objects,
93 int nr_objects,
94 const struct pack_idx_option *,
95 const unsigned char *sha1);
96int check_pack_crc(struct packed_git *p, struct pack_window **w_curs, off_t offset, off_t len, unsigned int nr);
97int verify_pack_index(struct packed_git *);
98int verify_pack(struct repository *, struct packed_git *, verify_fn fn, struct progress *, uint32_t);
99off_t write_pack_header(struct hashfile *f, uint32_t);
100void fixup_pack_header_footer(const struct git_hash_algo *, int,
101 unsigned char *, const char *, uint32_t,
102 unsigned char *, off_t);
103char *index_pack_lockfile(struct repository *r, int fd, int *is_well_formed);
104
105struct ref;
106
107void write_promisor_file(const char *promisor_name, struct ref **sought, int nr_sought);
108
109char *write_rev_file(struct repository *repo,
110 const char *rev_name,
111 struct pack_idx_entry **objects,
112 uint32_t nr_objects,
113 const unsigned char *hash,
114 unsigned flags);
115char *write_rev_file_order(struct repository *repo,
116 const char *rev_name,
117 uint32_t *pack_order,
118 uint32_t nr_objects,
119 const unsigned char *hash,
120 unsigned flags);
121
122/*
123 * The "hdr" output buffer should be at least this big, which will handle sizes
124 * up to 2^67.
125 */
126#define MAX_PACK_OBJECT_HEADER 10
127int encode_in_pack_object_header(unsigned char *hdr, int hdr_len,
128 enum object_type, uintmax_t);
129
130#define PH_ERROR_EOF (-1)
131#define PH_ERROR_PACK_SIGNATURE (-2)
132#define PH_ERROR_PROTOCOL (-3)
133int read_pack_header(int fd, struct pack_header *);
134
135struct packing_data;
136
137struct hashfile *create_tmp_packfile(struct repository *repo,
138 char **pack_tmp_name);
139void stage_tmp_packfiles(struct repository *repo,
140 struct strbuf *name_buffer,
141 const char *pack_tmp_name,
142 struct pack_idx_entry **written_list,
143 uint32_t nr_written,
144 struct packing_data *to_pack,
145 struct pack_idx_option *pack_idx_opts,
146 unsigned char hash[],
147 char **idx_tmp_name);
148void rename_tmp_packfile_idx(struct repository *repo,
149 struct strbuf *basename,
150 char **idx_tmp_name);
151
152#endif