move show_pack_info() where it belongs
[git/git.git] / pack.h
1 #ifndef PACK_H
2 #define PACK_H
3
4 #include "object.h"
5
6 /*
7 * Packed object header
8 */
9 #define PACK_SIGNATURE 0x5041434b /* "PACK" */
10 #define PACK_VERSION 2
11 #define pack_version_ok(v) ((v) == htonl(2) || (v) == htonl(3))
12 struct pack_header {
13 uint32_t hdr_signature;
14 uint32_t hdr_version;
15 uint32_t hdr_entries;
16 };
17
18 /*
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.
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
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.
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
37 /* These may be overridden by command-line parameters */
38 extern uint32_t pack_idx_default_version;
39 extern uint32_t pack_idx_off32_limit;
40
41 /*
42 * Packed object index header
43 */
44 struct pack_idx_header {
45 uint32_t idx_signature;
46 uint32_t idx_version;
47 };
48
49 /*
50 * Common part of object structure used for write_idx_file
51 */
52 struct pack_idx_entry {
53 unsigned char sha1[20];
54 uint32_t crc32;
55 off_t offset;
56 };
57
58 extern char *write_idx_file(char *index_name, struct pack_idx_entry **objects, int nr_objects, unsigned char *sha1);
59
60 extern int verify_pack(struct packed_git *);
61 extern void fixup_pack_header_footer(int, unsigned char *, const char *, uint32_t);
62 extern char *index_pack_lockfile(int fd);
63
64 #define PH_ERROR_EOF (-1)
65 #define PH_ERROR_PACK_SIGNATURE (-2)
66 #define PH_ERROR_PROTOCOL (-3)
67 extern int read_pack_header(int fd, struct pack_header *);
68 #endif