@leroysheep / BookAlchemy
Code Commits Pulls CI/CD 82,027
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1 #ifndef PACK_H
2 #define PACK_H
3
4 #include "object.h"
5 #include "csum-file.h"
6
7 struct packed_git;
8 struct pack_window;
9 struct 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)
18 struct 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
43 struct 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
66 void reset_pack_idx_option(struct pack_idx_option *);
67
68 /*
69 * Packed object index header
70 */
71 struct 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 */
79 struct pack_idx_entry {
80 struct object_id oid;
81 uint32_t crc32;
82 off_t offset;
83 };
84
85
86 struct progress;
87 /* Note, the data argument could be NULL if object type is blob */
88 typedef int (*verify_fn)(const struct object_id *oid,
89 enum object_type type,
90 unsigned long size,
91 void *buffer, int *eaten,
92 void *fn_data);
93
94 const char *write_idx_file(struct repository *repo,
95 const char *index_name,
96 struct pack_idx_entry **objects,
97 int nr_objects,
98 const struct pack_idx_option *,
99 const unsigned char *sha1);
100 int check_pack_crc(struct packed_git *p, struct pack_window **w_curs, off_t offset, off_t len, unsigned int nr);
101 int verify_pack_index(struct packed_git *);
102 int verify_pack(struct repository *, struct packed_git *, verify_fn fn, void *fn_data,
103 struct progress *, uint32_t);
104 off_t write_pack_header(struct hashfile *f, uint32_t);
105 void fixup_pack_header_footer(const struct git_hash_algo *, int,
106 unsigned char *, const char *, uint32_t,
107 unsigned char *, off_t);
108 char *index_pack_lockfile(struct repository *r, int fd, int *is_well_formed);
109
110 struct ref;
111
112 void write_promisor_file(const char *promisor_name, struct ref **sought, int nr_sought);
113
114 char *write_rev_file(struct repository *repo,
115 const char *rev_name,
116 struct pack_idx_entry **objects,
117 uint32_t nr_objects,
118 const unsigned char *hash,
119 unsigned flags);
120 char *write_rev_file_order(struct repository *repo,
121 const char *rev_name,
122 uint32_t *pack_order,
123 uint32_t nr_objects,
124 const unsigned char *hash,
125 unsigned flags);
126
127 /*
128 * The "hdr" output buffer should be at least this big, which will handle sizes
129 * up to 2^67.
130 */
131 #define MAX_PACK_OBJECT_HEADER 10
132 int encode_in_pack_object_header(unsigned char *hdr, int hdr_len,
133 enum object_type, uintmax_t);
134
135 #define PH_ERROR_EOF (-1)
136 #define PH_ERROR_PACK_SIGNATURE (-2)
137 #define PH_ERROR_PROTOCOL (-3)
138 int read_pack_header(int fd, struct pack_header *);
139
140 struct packing_data;
141
142 struct hashfile *create_tmp_packfile(struct repository *repo,
143 char **pack_tmp_name);
144 void stage_tmp_packfiles(struct repository *repo,
145 struct strbuf *name_buffer,
146 const char *pack_tmp_name,
147 struct pack_idx_entry **written_list,
148 uint32_t nr_written,
149 struct packing_data *to_pack,
150 struct pack_idx_option *pack_idx_opts,
151 unsigned char hash[],
152 char **idx_tmp_name);
153 void rename_tmp_packfile_idx(struct repository *repo,
154 struct strbuf *basename,
155 char **idx_tmp_name);
156
157 #endif