submodule: Use cat instead of echo to avoid DOS line-endings
[git/dscho.git] / pack.h
blob722a54e00a2cb7d9514c12f799fb1ec15930cf5d
1 #ifndef PACK_H
2 #define PACK_H
4 #include "object.h"
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;
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.
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.
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.
35 #define PACK_IDX_SIGNATURE 0xff744f63 /* "\377tOc" */
37 struct pack_idx_option {
38 unsigned flags;
39 /* flag bits */
40 #define WRITE_IDX_VERIFY 01
42 uint32_t version;
43 uint32_t off32_limit;
46 * List of offsets that would fit within off32_limit but
47 * need to be written out as 64-bit entity for byte-for-byte
48 * verification.
50 int anomaly_alloc, anomaly_nr;
51 uint32_t *anomaly;
54 extern void reset_pack_idx_option(struct pack_idx_option *);
57 * Packed object index header
59 struct pack_idx_header {
60 uint32_t idx_signature;
61 uint32_t idx_version;
65 * Common part of object structure used for write_idx_file
67 struct pack_idx_entry {
68 unsigned char sha1[20];
69 uint32_t crc32;
70 off_t offset;
73 extern const char *write_idx_file(const char *index_name, struct pack_idx_entry **objects, int nr_objects, const struct pack_idx_option *, unsigned char *sha1);
74 extern int check_pack_crc(struct packed_git *p, struct pack_window **w_curs, off_t offset, off_t len, unsigned int nr);
75 extern int verify_pack_index(struct packed_git *);
76 extern int verify_pack(struct packed_git *);
77 extern void fixup_pack_header_footer(int, unsigned char *, const char *, uint32_t, unsigned char *, off_t);
78 extern char *index_pack_lockfile(int fd);
79 extern int encode_in_pack_object_header(enum object_type, uintmax_t, unsigned char *);
81 #define PH_ERROR_EOF (-1)
82 #define PH_ERROR_PACK_SIGNATURE (-2)
83 #define PH_ERROR_PROTOCOL (-3)
84 extern int read_pack_header(int fd, struct pack_header *);
85 #endif