packfile: define and use bsearch_pack()
[git/git.git] / packfile.h
1 #ifndef PACKFILE_H
2 #define PACKFILE_H
3
4 #include "oidset.h"
5
6 /*
7 * Generate the filename to be used for a pack file with checksum "sha1" and
8 * extension "ext". The result is written into the strbuf "buf", overwriting
9 * any existing contents. A pointer to buf->buf is returned as a convenience.
10 *
11 * Example: odb_pack_name(out, sha1, "idx") => ".git/objects/pack/pack-1234..idx"
12 */
13 extern char *odb_pack_name(struct strbuf *buf, const unsigned char *sha1, const char *ext);
14
15 /*
16 * Return the name of the (local) packfile with the specified sha1 in
17 * its name. The return value is a pointer to memory that is
18 * overwritten each time this function is called.
19 */
20 extern char *sha1_pack_name(const unsigned char *sha1);
21
22 /*
23 * Return the name of the (local) pack index file with the specified
24 * sha1 in its name. The return value is a pointer to memory that is
25 * overwritten each time this function is called.
26 */
27 extern char *sha1_pack_index_name(const unsigned char *sha1);
28
29 extern struct packed_git *parse_pack_index(unsigned char *sha1, const char *idx_path);
30
31 /* A hook to report invalid files in pack directory */
32 #define PACKDIR_FILE_PACK 1
33 #define PACKDIR_FILE_IDX 2
34 #define PACKDIR_FILE_GARBAGE 4
35 extern void (*report_garbage)(unsigned seen_bits, const char *path);
36
37 extern void prepare_packed_git(void);
38 extern void reprepare_packed_git(void);
39 extern void install_packed_git(struct packed_git *pack);
40
41 /*
42 * Give a rough count of objects in the repository. This sacrifices accuracy
43 * for speed.
44 */
45 unsigned long approximate_object_count(void);
46
47 extern struct packed_git *find_sha1_pack(const unsigned char *sha1,
48 struct packed_git *packs);
49
50 extern void pack_report(void);
51
52 /*
53 * mmap the index file for the specified packfile (if it is not
54 * already mmapped). Return 0 on success.
55 */
56 extern int open_pack_index(struct packed_git *);
57
58 /*
59 * munmap the index file for the specified packfile (if it is
60 * currently mmapped).
61 */
62 extern void close_pack_index(struct packed_git *);
63
64 extern unsigned char *use_pack(struct packed_git *, struct pack_window **, off_t, unsigned long *);
65 extern void close_pack_windows(struct packed_git *);
66 extern void close_all_packs(void);
67 extern void unuse_pack(struct pack_window **);
68 extern void clear_delta_base_cache(void);
69 extern struct packed_git *add_packed_git(const char *path, size_t path_len, int local);
70
71 /*
72 * Make sure that a pointer access into an mmap'd index file is within bounds,
73 * and can provide at least 8 bytes of data.
74 *
75 * Note that this is only necessary for variable-length segments of the file
76 * (like the 64-bit extended offset table), as we compare the size to the
77 * fixed-length parts when we open the file.
78 */
79 extern void check_pack_index_ptr(const struct packed_git *p, const void *ptr);
80
81 /*
82 * Perform binary search on a pack-index for a given oid. Packfile is expected to
83 * have a valid pack-index.
84 *
85 * See 'bsearch_hash' for more information.
86 */
87 int bsearch_pack(const struct object_id *oid, const struct packed_git *p, uint32_t *result);
88
89 /*
90 * Return the SHA-1 of the nth object within the specified packfile.
91 * Open the index if it is not already open. The return value points
92 * at the SHA-1 within the mmapped index. Return NULL if there is an
93 * error.
94 */
95 extern const unsigned char *nth_packed_object_sha1(struct packed_git *, uint32_t n);
96 /*
97 * Like nth_packed_object_sha1, but write the data into the object specified by
98 * the the first argument. Returns the first argument on success, and NULL on
99 * error.
100 */
101 extern const struct object_id *nth_packed_object_oid(struct object_id *, struct packed_git *, uint32_t n);
102
103 /*
104 * Return the offset of the nth object within the specified packfile.
105 * The index must already be opened.
106 */
107 extern off_t nth_packed_object_offset(const struct packed_git *, uint32_t n);
108
109 /*
110 * If the object named sha1 is present in the specified packfile,
111 * return its offset within the packfile; otherwise, return 0.
112 */
113 extern off_t find_pack_entry_one(const unsigned char *sha1, struct packed_git *);
114
115 extern int is_pack_valid(struct packed_git *);
116 extern void *unpack_entry(struct packed_git *, off_t, enum object_type *, unsigned long *);
117 extern unsigned long unpack_object_header_buffer(const unsigned char *buf, unsigned long len, enum object_type *type, unsigned long *sizep);
118 extern unsigned long get_size_from_delta(struct packed_git *, struct pack_window **, off_t);
119 extern int unpack_object_header(struct packed_git *, struct pack_window **, off_t *, unsigned long *);
120
121 extern void release_pack_memory(size_t);
122
123 /* global flag to enable extra checks when accessing packed objects */
124 extern int do_check_packed_object_crc;
125
126 extern int packed_object_info(struct packed_git *pack, off_t offset, struct object_info *);
127
128 extern void mark_bad_packed_object(struct packed_git *p, const unsigned char *sha1);
129 extern const struct packed_git *has_packed_and_bad(const unsigned char *sha1);
130
131 extern int find_pack_entry(const unsigned char *sha1, struct pack_entry *e);
132
133 extern int has_sha1_pack(const unsigned char *sha1);
134
135 extern int has_pack_index(const unsigned char *sha1);
136
137 /*
138 * Only iterate over packs obtained from the promisor remote.
139 */
140 #define FOR_EACH_OBJECT_PROMISOR_ONLY 2
141
142 /*
143 * Iterate over packed objects in both the local
144 * repository and any alternates repositories (unless the
145 * FOR_EACH_OBJECT_LOCAL_ONLY flag, defined in cache.h, is set).
146 */
147 typedef int each_packed_object_fn(const struct object_id *oid,
148 struct packed_git *pack,
149 uint32_t pos,
150 void *data);
151 extern int for_each_packed_object(each_packed_object_fn, void *, unsigned flags);
152
153 /*
154 * Return 1 if an object in a promisor packfile is or refers to the given
155 * object, 0 otherwise.
156 */
157 extern int is_promisor_object(const struct object_id *oid);
158
159 #endif