Merge branch 'rb/hpe'
[git.git] / pack.h
blobda99fdd1d2baf7574b606f4c2bc6e1dcfeacf0fa
1 #ifndef PACK_H
2 #define PACK_H
4 #include "object.h"
5 #include "csum-file.h"
7 struct repository;
9 /*
10 * Packed object header
12 #define PACK_SIGNATURE 0x5041434b /* "PACK" */
13 #define PACK_VERSION 2
14 #define pack_version_ok(v) ((v) == htonl(2) || (v) == htonl(3))
15 struct pack_header {
16 uint32_t hdr_signature;
17 uint32_t hdr_version;
18 uint32_t hdr_entries;
22 * The first four bytes of index formats later than version 1 should
23 * start with this signature, as all older git binaries would find this
24 * value illegal and abort reading the file.
26 * This is the case because the number of objects in a packfile
27 * cannot exceed 1,431,660,000 as every object would need at least
28 * 3 bytes of data and the overall packfile cannot exceed 4 GiB with
29 * version 1 of the index file due to the offsets limited to 32 bits.
30 * Clearly the signature exceeds this maximum.
32 * Very old git binaries will also compare the first 4 bytes to the
33 * next 4 bytes in the index and abort with a "non-monotonic index"
34 * error if the second 4 byte word is smaller than the first 4
35 * byte word. This would be true in the proposed future index
36 * format as idx_signature would be greater than idx_version.
38 #define PACK_IDX_SIGNATURE 0xff744f63 /* "\377tOc" */
40 struct pack_idx_option {
41 unsigned flags;
42 /* flag bits */
43 #define WRITE_IDX_VERIFY 01 /* verify only, do not write the idx file */
44 #define WRITE_IDX_STRICT 02
46 uint32_t version;
47 uint32_t off32_limit;
50 * List of offsets that would fit within off32_limit but
51 * need to be written out as 64-bit entity for byte-for-byte
52 * verification.
54 int anomaly_alloc, anomaly_nr;
55 uint32_t *anomaly;
58 extern void reset_pack_idx_option(struct pack_idx_option *);
61 * Packed object index header
63 struct pack_idx_header {
64 uint32_t idx_signature;
65 uint32_t idx_version;
69 * Common part of object structure used for write_idx_file
71 struct pack_idx_entry {
72 struct object_id oid;
73 uint32_t crc32;
74 off_t offset;
78 struct progress;
79 /* Note, the data argument could be NULL if object type is blob */
80 typedef int (*verify_fn)(const struct object_id *, enum object_type, unsigned long, void*, int*);
82 extern const char *write_idx_file(const char *index_name, struct pack_idx_entry **objects, int nr_objects, const struct pack_idx_option *, const unsigned char *sha1);
83 extern int check_pack_crc(struct packed_git *p, struct pack_window **w_curs, off_t offset, off_t len, unsigned int nr);
84 extern int verify_pack_index(struct packed_git *);
85 extern int verify_pack(struct repository *, struct packed_git *, verify_fn fn, struct progress *, uint32_t);
86 extern off_t write_pack_header(struct hashfile *f, uint32_t);
87 extern void fixup_pack_header_footer(int, unsigned char *, const char *, uint32_t, unsigned char *, off_t);
88 extern char *index_pack_lockfile(int fd);
91 * The "hdr" output buffer should be at least this big, which will handle sizes
92 * up to 2^67.
94 #define MAX_PACK_OBJECT_HEADER 10
95 extern int encode_in_pack_object_header(unsigned char *hdr, int hdr_len,
96 enum object_type, uintmax_t);
98 #define PH_ERROR_EOF (-1)
99 #define PH_ERROR_PACK_SIGNATURE (-2)
100 #define PH_ERROR_PROTOCOL (-3)
101 extern int read_pack_header(int fd, struct pack_header *);
103 extern struct hashfile *create_tmp_packfile(char **pack_tmp_name);
104 extern void finish_tmp_packfile(struct strbuf *name_buffer, const char *pack_tmp_name, struct pack_idx_entry **written_list, uint32_t nr_written, struct pack_idx_option *pack_idx_opts, unsigned char sha1[]);
106 #endif